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Harrop, John P. „Improving the Army's joint platform allocation tool (JPAT)“. Thesis, Monterey, California: Naval Postgraduate School, 2013. http://hdl.handle.net/10945/37635.
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Approved for public release; distribution is unlimitedThe U.S. Army's joint platform allocation tool (JPAT) is an integer linear program that was developed by the Army's Training and Doctrine Command Analysis Center and the Naval Postgraduate School to help inform acquisition decisions involving aerial reconnaissance and surveillance (R&S) resources. JPAT evaluates inputs such as mission requirements, locations of available equipment, and budgetary constraints to determine an effective assignment of unmanned aerial R&S assets to missions. As of September 2013, JPAT is solved using a rolling horizon approach, which produces a sub-optimal solution, and requires substantial computational resources to solve a problem of realistic size. Because JPAT is an integer linear program, it is a suitable candidate for using decomposition techniques to improve its computational efficiency. This thesis conducts an analysis of multiple approaches for increasing JPAT's computational efficiency. First, we reformulate JPAT using Benders decomposition. Then, we solve both the original and decomposed formulations using the simplex and barrier algorithms with multiple size datasets. In addition, we experiment with an initial heuristic solution and other techniques in our attempts to improve JPAT's runtime. We find that while Benders decomposition does not result in significant improvements in computation time for the instances considered in this thesis, initial solution heuristics and other modifications to the model improve JPAT's performance.
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Luo, Lu. „Joint routing and resource allocation in multihop wireless network /“. View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20LUOL.
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Lahad, Bachir. „Joint Uplink/Downlink Radio Resource Allocation in 5G HetNets“. Electronic Thesis or Diss., université Paris-Saclay, 2020. http://www.theses.fr/2020UPASG057.
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La croissance rapide du trafic de données sans fil et des services intensifs en bande passante (voix sur IP, streaming vidéo, live streaming, etc.) nécessite de trouver des solutions viables pour améliorer la qualité de service et maximiser les performances du réseau. Pour s'adapter à ces applications intensives en bande passante, les réseaux cellulaires hétérogènes (HetNets) ont été introduits dans le 3GPP comme l'une des principales caractéristiques pour répondre à ces exigences avancées.Maintenant, en raison de la différence de charges de trafic de liaison montante (UL) et de liaison descendante (DL) attendues dans les prochaines générations HetNets, il devient essentiel d'ajuster dynamiquement les ressources UL/DL. Pour soutenir cette nouvelle approche, le duplexage temporel (TDD) dynamique a été proposé. Néanmoins, l'importance d'UL se pose avec l'évolution des réseaux sociaux et des solutions cloud. Par conséquent, il est très intéressant d’introduire de nouvelles techniques qui atténuent les interférences de l’UL, améliorent les débits UL et DL et permettent également une meilleure utilisation des ressources radio en fournissant un équilibrage de charge adéquat entre UL et DL. Une telle caractéristique supplémentaire est le découplage accès UL/DL.Dans notre travail, nous développons d'abord un modèle TDD dans HetNets. Dans ce modèle, nous dérivons des expressions analytiques pour la distribution de l'emplacement du brouilleur considérant tous les scénarios d’interférences possibles qui pourraient se produire dans les réseaux basés sur TDD, tout en tenant compte de l'impact nocif de cette interférence.Basé sur ce dernier résultat, nous dérivons la fonction de distribution et de génération de moment (MGF) de l’interférence intercellulaire montante et descendante considérant un réseau composé d'une macro-cellule et d'une petite cellule. Nous nous appuyons sur les expressions dérivées pour analyser la capacité moyenne de la cellule de référence dans les transmissions en liaison montante et en liaison descendante.Deuxièmement, nous développons un modèle statistique conjoint TDD/découplage pour mettre en évidence les avantages que le mode d'accès de découplage peut apporter à un système basé sur HetNet TDD. L'introduction du mode de découplage nécessite une analyse approfondie de l’étude de comparaison avec le mode d'accès couplé UL/DL conventionnel. Par conséquent, nous dérivons les statistiques du signal d'interférence et du signal d'intérêt des deux modes, puis analysons leur impact sur le performance du système.Ce travail a été étendu pour inclure le déploiement de plusieurs petites cellules, où des aperçus supplémentaires sur les avantages du mode de découplage sont fournies en termes de gains de découplage UL et DL. Suite à la mise en œuvre du modèle développé, il est démontré que le cas de découplage apporte de plus grands avantages dans la liaison montante et maintient la même amélioration dans la liaison descendante pour diverses valeurs de décalage et, ainsi, améliore les performances globales du système lorsqu'il est associé avec une technologie TDD dynamique. Il est en outre démontré que notre réseau modélisé peut être optimisé en adoptant la combinaison optimale à la fois du facteur de décalage des petites cellules et de la distance entre les petites cellules.D'un autre côté, l'évaluation des avantages d'un TDD adaptatif et du découplage dans un système basé sur HetNet en fonction des charges de trafic variant dans le temps, nécessite de trouver un simulateur de niveau système où nous pouvons présenter le motif derrière l' adoption de découplage et de TDD dynamique. À partir des scénarios de simulation mise en œuvre, il est observé que l'algorithme adaptatif proposé apporte des améliorations de performances significatives dans le débit UL et DL par rapport à un certain nombre de schémas conventionnels, principalement dans les systèmes fortement chargésThe rapid growth in wireless data traffic and bandwidth intensive services (voice over IP, video streaming, livestreaming, etc.) necessitates finding viable solutions to improve service quality and maximize thenetwork performance. To accommodate these bandwidth intensive applications, heterogeneous cellular networks (HetNets) were introduced in 3GPP as one of the main features to meet these advanced requirements. Yet, because of the difference in uplink (UL) and downlink (DL) traffic loads expected in the next HetNetsgeneration, it becomes essential to dynamically adjust UL/DL resources. To support this newapproach, dynamic time-division duplexing (TDD) has been proposed. Nevertheless, the importance of UL arises along with the evolution of social networking and cloudsolutions. Therefore, it is of great interest to introduce novel techniques that mitigate ULinterferences, improve UL and DL throughputs and allow as well, a better use of radio resources byproviding adequate load balancing among UL and DL. Such an additional feature is the decoupledUL/DL access.In our work, we first develop a TDD model in HetNets. Under this model, we derive analytical expressions for the distribution of the interferer location considering all possible interference scenarios that could occur in TDD-based networks, while taking into account the harmful impact of interference.Based on the latter result, we derive the distribution and moment generating function (MGF) of the uplink and downlinkinter-cell interference considering a network consisting of one macro cell and one small cell. We build on the derivedexpressions to analyze the average capacity of the reference cell in both uplink and downlink transmissions.Second, we develop a joint TDD/decoupling statistical model to highlight the benefits thatthe decoupling access mode can bring to a HetNet TDD based system, in terms of UL and DL spectral efficiencies and throughputs. Introducing the decoupling mode necessitates a thoroughcomparison study with the conventional coupled UL/DL access mode. Therefore, we derive the statistics of the interference signal and the signal of interest of both modes and then analyze their impact on the system performance.This work was extended to include multiple small cells deployment, where more insight into the benefits of decoupling mode is provided in terms of UL and DL decoupling gains. Further to the implementation of the developed model, it is shown that the decoupling case brings greater benefits in the uplink and maintains the same improvement in the downlink for various offset values and thus, improves the overall system performance when being combined with a dynamic TDD technology. It is further shown that our modeled network can be optimized by adopting the optimal combination of both the small cell offset factor and the distance between small cells.On the other hand, evaluating the benefits of an adaptive TDD and decoupling in a HetNet based system according to time-variant traffic loads, necessitates findinga system level simulator where we can present the motivation and accurately assess the role of both decoupling and dynamic TDD techniques in the UL/DL optimization problem. From the applied simulation scenarios, it is observed that the proposed adaptive algorithm (dynamic TDD with decoupling policies) yields significant performance improvements in UL and DL throughput compared to a number of conventional schemes, mainly in dense HetNet deployment and in highly loaded systems
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Tervo, V. (Valtteri). „Joint multiuser power allocation and iterative multi-antenna receiver design“. Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526207292.
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Abstract This thesis concentrates on joint optimization of transmit power allocation and receive filtering in multiuser, multi-antenna communications. Due to the increasing number of wireless devices, the design of energy-efficient communication links is becoming increasingly important. In cellular mobile communications, reducing the average power consumption in uplink transmission is beneficial for users in order to extend battery life and, hence, energy efficiency in general. However, the power consumption of the high power amplifier (HPA) at the transmitter depends on the peak power of the transmission. This thesis focuses on power allocation problems for single-carrier (SC) frequency division multiple access (FDMA) and orthogonal FDMA (OFDMA) transmission assuming iterative reception. The goal in the first scheme presented in this thesis is to reduce the average power consumption by designing a power allocation method that takes into account the convergence properties of an iterative receiver in multiuser uplink communications. The proposed scheme can guarantee that the desired quality of service (QoS) is achieved after a sufficient number of iterations. Reducing the peak-to-average power ratio (PAPR) in any transmission system is beneficial because it allows the use of inexpensive, energy-efficient power amplifiers. The goal in the second scheme presented in this thesis is to control the PAPR of the transmitted signal. Hence, in addition to the QoS constraint, the instantaneous PAPR constraint is derived for SC-FDMA and OFDMA transmission. Moreover, a statistical approach is considered in which the power variance of the transmitted waveform is controlled. The QoS and PAPR constraints are considered jointly and, therefore, the proposed power allocation strategy jointly takes into account the channel quality and the PAPR characteristics of the power amplifier. However, the PAPR constraint can be adopted to any SC-FDMA or OFDMA framework and it is not restricted to the scheme presented in this thesis. The objective of the optimization problems considered throughout the thesis is to minimize the sum power. The majority of the derived constraints are non-convex and therefore, two alternative successive convex approximations (SCAs) are derived for all the non-convex constraints considered. The numerical results show that the proposed power allocation strategies can significantly reduce the average transmission power of users while allowing flexible PAPR control. Hence, the proposed methods can be used to extend battery life for users and especially improve the QoS at the cell edgesTiivistelmä Väitöskirjassa tutkitaan lähettimessä tapahtuvan tehoallokoinnin sekä vastaanottimessa tapahtuvan signaalin suodatuksen yhteisoptimointia monikäyttöön suunnatussa langattomassa moniantennikommunikaatiossa. Langattomien laitteiden lukumäärän kasvaessa energiatehokkuuden merkitys tiedonsiirtolinkkien suunnittelussa korostuu. Soluihin perustuvassa langattomassa tietoliikenteessä keskimääräisen tehonkulutuksen pienentäminen ylälinkkilähetyksessä (käyttäjältä tukiasemaan) on tärkeää käyttäjän kannalta, sillä se pidentää laitteen akun kestoa. Lähettimen tehovahvistimen (high power amplifier (HPA)) tehonkulutus on kuitenkin verrannollinen lähetyksen huipputehoon. Väitöskirjassa luodaaan uusia menetelmiä sekä vertaillaan tehoallokointia yhden kantoaallon taajuustason monikäyttöön (single carrier frequency division multiple access (SC-FDMA)) ja ortogonaalisen taajuustason monikäyttöön (orthogonal FDMA (OFDMA)) perustuvissa lähetysteknologioissa. Työn ensimmäisessä osiossa tavoitteena on keskimääräisen tehonkulutuksen pienentäminen monen käyttäjän ylälinkkikommunikaatiossa suunnittelemalla tehoallokointimenetelmä, joka ottaa huomioon iteratiivisen vastaanottimen konvergenssiominaisuudet. Työssä ehdotettu menetelmä takaa vastaanotetun informaation halutun laadun (quality of service (QoS)) riittävän monen vastaanottimessa tehdyn iteraation jälkeen. Huipputehon ja keskitehon suhteen (peak to average power ratio (PAPR)) pienentäminen missä tahansa lähetyksessä on hyödyllistä, sillä sen ansiosta voidaan käyttää energiatehokkaampia ja halvempia tehovahvistimia. Työn jälkimmäisessä osiossa tavoitteena on kontrolloida lähetetyn signaalin huipputehon ja keskitehon suhdetta. Työn ensimmäisessä osiossa esitetyn QoS-rajoitteen lisäksi tehoallokointia rajoitetaan symbolisekvenssikohtaisella PAPR-rajoitteella SCFDMA- ja OFDMA-lähetyksessä. Lisäksi esitetään tilastollinen menetelmä, jossa rajoitetaan lähetetyn signaalin tehon varianssia. Kun käytetään yhtäaikaisesti QoS- ja PAPR-rajoitteita, voidaan tiedonsiirtokanavaan suunnitella optimaalinen tehoallokointi ottaen huomioon tehovahvistimen epälineaarisuudet. Työssä esitetty PAPR-rajoite on kuitenkin geneerinen, ja se voidaan sovittaa mihin tahansa SCFDMA- tai OFDMA- optimointikehykseen. Työssä esitettävien optimointiongelmien tavoitteena on käyttäjien summatehon minimointi. Suurin osa työssä esiintyvistä ongelmista on ei-konvekseja, joten siinä esitetään kaksi vaihtoehtoista peräkkäinen konveksi approksimaatio (successive convex approximation (SCA)) -menetelmää kaikille ei-konvekseille rajoitteille. Numeeriset tulokset osoittavat, että esitetyt tehoallokointimenetelmät pienentävät merkittävästi keskimääräistä tehonkulutusta mahdollistaen lisäksi adaptiivisen PAPR-kontrolloinnin. Väitöskirjassa esitettyjen menetelmien avulla voidaan pidentää mobiilikäyttäjien akun kestoa sekä erityisesti parantaa solun reunakäyttäjien palvelun laatua
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Gecili, Hakan. „Joint Shelf Design and Shelf Space Allocation Problem for Retailers“. Wright State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=wright1594374475655644.
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Abdul, Aziz Hasan Ali Aamir, und Muhammad Adil Shahzad. „A Joint Subcarrier/Power allocation Scheme for OFDMA-based Cellular Networks“. Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-91310.
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The assignment of this master thesis consists of initiating power, subcarrier allocation in a dynamic FFR based scheme designed for multi-cell OFDMA networks and to enhance the throughput of all center users in bandwidth hungry borrower cells (overloaded cells) which was previously degraded by original FFR3 scheme as a result of partitioning of system bandwidth into center and edge bands respectively. The method uses band borrowing to compensate center user’s throughput loss in a semi and fully overloaded system. The scheme uses dynamic programming method (0/1 knapsack problem) to bargain an edge band on various power levels and tends to check the best combination (power and sub-carrier) which the system can utilize while still maintaining acceptable throughput loss for the users at the edge of the neighboring cell (lender cell). The algorithm consists of generating a borrowing request to neighboring cells for utilizing their edge bands by the overloaded borrower cell if their average center user throughput reaches below a minimum threshold value set in the system. The borrowing method uses 0/1 knapsack problem to capture an edge band based on limiting factors of total cost in average throughput losses by neighbors (Ci) and Un (tolerable mean user edge user throughput loss by lending cell). While solving knapsack problem the lender (neighbors) will check Ci and Un before granting the right to use its edge band. The later stage requires reducing subcarrier power level in order to utilize the lenders edge band using "soft borrower" mode. The borrowed sub-carriers will be activated take power from the original center band sub-carriers of the overloaded cell by taking into account the interference between the lender and the borrower. In case of negative (0) reply from the lender cell after the first request, multiple requests are generated at reduce power level at every step to order to acquire more bands. If a neighbor has band borrowing requests from multiple overloaded base stations, the band will be granted to the one which gives minimal loss in terms of throughput to the lender cell. The simulation results are analyzed w.r.t reuse-1 and FFR3 scheme of a multi cell regular and irregular scenarios comprising of lightly to heavily overloaded cells with various subcarrier allocation patterns. An overhead and time assessment is also presented between borrower and lender cells. Simulation results show an increase of 60% in center user’s throughput w.r.t original FFR3 scheme with an acceptable loss of 18% at the edges in complex overloaded scenarios while the overall system throughout increases by 35%.
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Fallgren, Mikael. „Optimization of Joint Cell, Channel and Power Allocation in Wireless Communication Networks“. Doctoral thesis, KTH, Optimeringslära och systemteori, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-40274.
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In this thesis we formulate joint cell, channel and power allocation problems within wireless communication networks. The objectives are to maximize the user with mini- mum data throughput (Shannon capacity) or to maximize the total system throughput, referred to as the max-min and max-sum problem respectively. The complexity is stud- ied together with proposed optimization- and heuristic-based approaches. In the first paper an overall joint cell, channel and power allocation max-min prob- lem is formulated. We show that the decision problem is NP-hard and that the op- timization problem is not approximable unless P is equal to NP, for instances with a sufficiently large number of channels. Further, it follows that for a feasible binary cell and channel allocation, the remaining continuous power allocation optimization problem is still not approximable unless P is equal to NP. In addition, it is shown that first-order optimality conditions give global optimum of the single channel power al- location optimization problem, although the problem is in general not convex. In the following two papers heuristics for solving the overall problem are proposed. In the second paper we consider the single channel problem with convex combinations of the max-min and the max-sum objective functions. This variable utility provides the ability of tuning the amount of fairness and total throughput. The third paper investi- gates the multiple channel setting. On a system with three cells, eight mobile users and three channels, we perform an exhaustive search over feasible cell and channel alloca- tions. The exhaustive search is then compared to the less computationally expensive heuristic approaches, presenting potential earnings to strive for. A conclusion is that several of the proposed heuristics perform very well. The final paper incorporates fixed relay stations into the overall joint cell, channel and power allocation max-min problem. The complexity is inherited from the formula- tion without relay stations. Further, we propose a heuristic channel allocation approach that shows good performance, compared to an optimization based approach, in numer- ical simulations on the relay setting.Financial support by the Swedish Foundation for Strategic Research (SSF) QC 20110915
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Mao, Shaobo. „Joint energy allocation for sensing and transmission in rechargeable wireless sensor networks“. Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42832.
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The energy management policy of a rechargeable wireless sensor network (WSN) needs to take into account the energy harvesting process, and is thus different from that of a traditional WSN powered by non-rechargeable batteries. In this thesis, we study the energy allocation for sensing and transmission in an energy harvesting sensor node with a rechargeable battery. The sensor aims to maximize the expected total amount of data transmitted subject to time-varying energy harvesting rate, energy availability in the battery, data availability in the data buffer, and channel fading. In this thesis, we first consider the energy allocation problem that assumes a fixed sensor lifetime. Then, we extend the energy allocation problem by taking into account the randomness of the senor lifetime.
In the first part of this thesis, we study the joint energy allocation for sensing and transmission in an energy harvesting sensor node with a fixed sensor lifetime. We formulate the energy allocation problem as a finite-horizon Markov decision process
(MDP) and propose an optimal energy allocation (OEA) algorithm using backward induction. We conduct simulations to compare the performance between our proposed OEA algorithm and the channel-aware energy allocation (CAEA) algorithm extended from [1]. Simulation results show that the OEA algorithm can transmit a much larger amount of data over a finite horizon than the CAEA algorithm under different settings.
In the second part of this thesis, we extend the joint energy allocation problem by taking into account the randomness of the sensor lifetime, and formulate the problem as an infinite-horizon discounted MDP. We propose an optimal stationary energy allocation (OSEA) algorithm using the value iteration. We then consider a special case with infinite data backlog and prove that the optimal transmission energy allocation (OTEA) policy is monotone with respect to the amount of battery energy available. Finally, we conduct extensive simulations to compare the performance of the OSEA, OTEA, and CAEA algorithms. Results show that the OSEA algorithm transmits the largest amount of data, and the OTEA algorithm can achieve a near-optimal performance.
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Wei, Junyi. „QoS-aware joint power and subchannel allocation algorithms for wireless network virtualization“. Thesis, University of Essex, 2017. http://repository.essex.ac.uk/20142/.
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Wireless network virtualization (WNV) is a promising technology which aims to overcome the network redundancy problems of the current Internet. WNV involves abstraction and sharing of resources among different parties. It has been considered as a long term solution for the future Internet due to its flexibility and feasibility. WNV separates the traditional Internet service provider’s role into the infrastructure provider (InP) and service provider (SP). The InP owns all physical resources while SPs borrow such resources to create their own virtual networks in order to provide services to end users. Because the radio resources is finite, it is sensible to introduce WNV to improve resources efficiency. This thesis proposes three resource allocation algorithms on an orthogonal frequency division multiple access (OFDMA)-based WNV transmission system aiming to improve resources utility. The subject of the first algorithm is to maximize the InP and virtual network operators’ (VNOs’) total throughput by means of subchannel allocation. The second one is a power allocation algorithm which aims to improve VNO’s energy efficiency. In addition, this algorithm also balances the competition across VNOs. Finally, a joint power and subchannel allocation algorithm is proposed. This algorithm tries to find out the overall transmission rate. Moreover, all the above alogorithms consider the InP’s quality of service (QoS) requirement in terms of data rate. The evaluation results indicates that the joint resource allocation algorithm has a better performance than others. Furthermore, the results also can be a guideline for WNV performance guarantees.
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Ngo, K. (KienTrung). „Joint energy harvesting time allocation and beamforming in two-way relaying network“. Master's thesis, University of Oulu, 2019. http://jultika.oulu.fi/Record/nbnfioulu-201902271252.
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Abstract. A two-way relaying system with amplify-and-forward technique, where relay stations (RSs) acquire the energy from transmission signal and interferences, is considered. The RSs use the energy to amplify the signal received from the transmitter and forward it to the receiver. Particularly, energy harvesting (EH) and time switching (TS) are deployed. Based on the TS architecture, we divide transmission time into two time slots, which are EH phase and information transmission (IT) phase. In the EH phase, the RSs harvest the energy from the received radio frequency (RF) signal. In the IT phase, the RSs process and forward the transmission signal to the destination by energy harvesting during the EH phase. From such a transmission scheme, we investigate the optimal time ratio of the EH and IT phase as well as the beamforming at RSs in order to acquire the sum rate maximization. Since the sum-rate maximization problem is nonconvex, we develop an iterative algorithm based on the majorization-minimization (MM) technique to solve the problem. Furthermore, we deployed two schemes to overcome the self-interference to see the efficiency of each scheme related to sum-rate performance. The results show that power transmission and a number of relay station have a major impact on the sum rate performance of the two-way relay system.
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Gong, Xuan. „Cross-layer design through joint routing and link allocation in wireless sensor networks“. Diss., Rolla, Mo. : Missouri University of Science and Technology, 2008. http://scholarsmine.mst.edu/thesis/pdf/xgwt2_09007dcc8053a770.pdf.
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Thesis (M.S.)--Missouri University of Science and Technology, 2008.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed August 15, 2008) Includes bibliographical references (p. 49-55).
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Nesbitt, Jesse. „Robust Optimization in Operational Risk: A Study of the Joint Platform Allocation Tool“. Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/43063.
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The Joint Platform Allocation Tool (JPAT) is a tool currently used to inform Army decision makers on resource management, procurement, and operational employment of Army aerial intelligence, surveillance, and reconnaissance (ISR) assets. The tool is modeled and implemented using point estimates for input data on future resource, equipment capability, and employment demand. This research expands the capability of the JPAT to account for uncertainty and changes in those parameters that bear on the overall operational risk of the Army's ISR mission: uncertain and changing future budgets, and uncertainty and unpredictability of future operational demands for ISR assets. Techniques of robust optimization are explored and applied to JPAT, and results and methodology are shown to be applicable to other operational areas.
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Saeed, Arsalan. „Efficient resource allocation for joint operation of large and small-cell heterogeneous networks“. Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/810343/.
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This thesis investigates the downlink resource allocation problem in Orthogonal Frequency Division Multiple Access (OFDMA) Heterogeneous Networks (HetNets) consisting of macro-cells and small-cells sharing the same frequency band. Dense deployment of small-cells overlaid by a macro layer is considered to be one of the most promising solutions for providing hotspot coverage in future 5G networks. The focus is to devise optimised policies for small-cells’ access to the shared spectrum, in terms of their transmissions, in order to maximise small-cell served users sum data rate while ensuring that certain level of quality of service (QoS) for the macro-cell users in the vicinity of small-cells is provided. We obtain the optimal solution to the resource allocation problem by employing the well-known Dual Lagrangian method. The formulated resource allocation problem is decomposed into N sub-problem at each Resource Block (RB). The optimal transmit power and RB allocation for each small-cell is obtained by updating the dual variables based on sub-gradient method. Furthermore, a low complexity heuristic solution based on binary integer linear programming is proposed for practical systems, and its performance is analysed in comparison with Reuse-1 and orthogonal frequency reuse cases. Alongside considering the data channel protection for macro-cell served users in the vicinity of small-cells, we also cater for control channel constraints. Since the control channel holds key information to decode data channel information, and if control channel is lost the data channel performance will be severely affected. We formulate the joint control and data channel resource allocation problem in HetNets. The solution to the complex problem is addressed by two low complexity heuristic solutions. The proposed interference aware heuristic solution is based on a progressive iterative approach which has significantly lower complexity compared to the optimal case. Whilst the aim is to maximise the net data-rate performance of the small-cells, we also address the energy efficiency issues in dense small-cell networks. We formulate the optimisation problem to minimise the small-cells’ energy consumption by making use of sleep-mode capabilities. The solution to the problem is provided by another heuristic algorithm which addresses the interference problem as well as the energy consumption minimisation. The interference minimisation phase is updated on a shorter intervals, whereas sleep mode phase takes place on larger time scales, considering the wake-up delays associate with practical networks. The potential energy saving gains are extensively examined by hypothetically making use of call data records from City of Milan. This real data helps highlight the potential of energy savings by making use of small-cells’ sleep-mode capabilities along with our proposed algorithm.
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Xie, Shiguang. „Optimal Allocation of Resources for Screening of Donated Blood“. Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/39259.
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Blood products, either whole blood or its components, are vital healthcare commodities for patients across all age groups, multiple diagnoses, and in a variety of settings. Meanwhile, blood shortages are common, and are projected to significantly increase in the near future in both developing and developed countries due to a limited supply of and increasing demand for blood, lack of resources, infrastructure. Unfortunately, today there remains a definable risk associated with the transfusion of blood and blood products. We explored, in depth, the resource allocation problem in reducing the risks of transfusion-transmitted infections (TTI). We developed models and algorithms to study the problem of selecting a set of blood screening tests for risk reduction, which we show to be very efficient in numerical studies with realistic-sized problems. This analysis also motivates the development of effective lower bounds with co-infection; our analysis indicates that these algorithms are very efficient and effective for the general problem. We also incorporate other objective functions and constraints (i.e., waste) into the analysis. Waste, defined as the fraction of disposed blood in the ``infection-free" blood, is incorporated into the risk-based model as a constraint. As an important extension, we compared our results of the blood screening problem in risk model with that of weighted risk objectives, which allows for different weights for each TTI. We further explored efficient algorithms to study this extension of the model and analyze how the test composition changes with the different objectives. Finally, in the context of blood screening, the last extension we investigated is to include a ``differential" testing policy, in which an optimal solution is allowed to contain multiple test sets, each applied to a fraction of the total blood units. In particular, the decision-maker faces the problem of selecting a collection of test sets as well as determining the proportion (or fraction) of blood units each test set will be administered to. We proposed the solution methodology and determined how the test sets under differential policy relate to those under the "same-for-all" policy; and how these changes impact the risk, and allow for better budget utilization.Ph. D.
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Karki, Uttam. „Joint Determination of Rack Configuration and Shelf Space Allocation to Maximize Retail Impulse Profit“. Wright State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=wright1578912008563221.
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Sharawi, Abeer Tarief. „OPTIMIZATION MODELS FOR EMERGENCY RELIEF SHELTER PLANNING FOR ANTICIPATED HURRICANE EVENTS“. Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4151.
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Natural disasters, specifically hurricanes, can cause catastrophic loss of life and property. In recent years, the United States has endured significant losses due to a series of devastating hurricanes (e.g., Hurricanes Charley and Ivan in 2004, and Hurricanes Katrina and Wilma in 2005). Several Federal authorities report that there are weaknesses in the emergency and disaster planning and response models that are currently employed in practice, thus creating a need for better decision models in emergency situations. The current models not only lack fast communication with emergency responders and the public, but are also inadequate for advising the pre-positioning of supplies at emergency shelters before the storm's impact. The problem of emergency evacuation relief shelter planning during anticipated hurricane events is addressed in this research. The shelter planning problem is modeled as a joint location-allocation-inventory problem, where the number and location of shelter facilities must be identified. In addition, the evacuating citizens must be assigned to the designated shelter facilities, and the amount of emergency supply inventory to pre-position at each facility must be determined. The objective is to minimize total emergency evacuation costs, which is equal to the combined facility opening and preparation cost, evacuee transportation cost and emergency supply inventory cost. A review of the emergency evacuation planning literature reveals that this class of problems has not been largely addressed to date. First, the emergency evacuation relief sheltering problem is formulated under deterministic conditions as a mixed integer non-linear programming (MINLP) model. For three different evacuation scenarios, the proposed MINLP model yields a plan that identifies the locations of relief shelters for evacuees, the assignment of evacuees to those shelters and the amount of emergency supplies to stockpile in advance of an anticipated hurricane. The MINLP model is then used (with minor modifications) to explore the idea of equally distributing the evacuees across the open shelters. The results for the three different scenarios indicate that a balanced utilization of the open shelters is achieved with little increase in the total evacuation cost. Next, the MINLP is enhanced to consider the stochastic characteristics of both hurricane strength and projected trajectory, which can directly influence the storm's behavior. The hurricane's strength is based on its hurricane category according to the Saffir-Simpson Hurricane Scale. Its trajectory is represented as a Markov chain, where the storm's path is modeled as transitions among states (i.e., coordinate locations) within a spherical coordinate system. A specific hurricane that made landfall in the state of Florida is used as a test case for the model. Finally, the stochastic model is employed within a robust optimization strategy, where several probable hurricane behavioral scenarios are solved. Then, a single, robust evacuation sheltering plan that provides the best results, not only in terms of maximum deviation of total evacuation cost across the likely scenarios, but also in terms of maximum deviation of unmet evacuee demand at the shelter locations, is generated. The practical value of this robust plan is quite significant. This plan should accommodate unexpected changes in the behavior of an approaching storm to a reasonable degree with minimal negative impact to the total evacuation cost and the fulfillment of evacuee demand at the shelter locations. Most importantly, the re-allocation and re-mobilization of emergency personnel and supplies are not required, which can cause confusion and potentially increase the response time of responders to the hurricane emergency. The computational results show the promise of this research and usefulness of the proposed models. This work is an initial step in addressing the simultaneous identification of shelter locations, assignment of citizens to those shelters, and determination of a policy for stockpiling emergency supplies in advance of a hurricane. Both the location-allocation problem and the inventory problem have been extensively and individually studied by researchers as well as practitioners. However, this joint location-allocation-inventory problem is a difficult problem to solve, especially in the presence of stochastic storm behavior. The proposed models, even in the deterministic case, are a significant step beyond the current state-of-the-art in the area of emergency and disaster planning.Ph.D.
Department of Industrial Engineering and Management Systems
Engineering and Computer Science
Industrial Engineering PhD
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Freye, Jeffrey T. „Design of experiment analysis for the Joint Dynamic Allocation of Fires and Sensors (JDAFS) simulation“. Thesis, Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion-image.exe/07Jun%5FFreye.pdf.
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Thesis (M.S. in Operations Research)--Naval Postgraduate School, June 2007.Thesis Advisor(s): Lucas, Thomas W. . "June 2007." Description based on title screen as viewed on August 15, 2007. Includes bibliographical references (p. 135-137). Also available in print.
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Teague, Kory Alan. „Approaches to Joint Base Station Selection and Adaptive Slicing in Virtualized Wireless Networks“. Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/85966.
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Wireless network virtualization is a promising avenue of research for next-generation 5G cellular networks. This work investigates the problem of selecting base stations to construct virtual networks for a set of service providers, and adaptive slicing of the resources between the service providers to satisfy service provider demands. A two-stage stochastic optimization framework is introduced to solve this problem, and two methods are presented for approximating the stochastic model. The first method uses a sampling approach applied to the deterministic equivalent program of the stochastic model. The second method uses a genetic algorithm for base station selection and adaptively slicing via a single-stage linear optimization problem. A number of scenarios are simulated using a log-normal model designed to emulate demand from real world cellular networks. Simulations indicate that the first approach can provide a reasonably tight solution, but is constrained as the time expense grows exponentially with the number of parameters. The second approach provides a significant improvement in run time with the introduction of marginal error.Master of Science
5G, the next generation cellular network standard, promises to provide significant improvements over current generation standards. For 5G to be successful, this must be accompanied by similarly significant efficiency improvements. Wireless network virtualization is a promising technology that has been shown to improve the cost efficiency of current generation cellular networks. By abstracting the physical resource—such as cell tower base stations— from the use of the resource, virtual resources are formed. This work investigates the problem of selecting virtual resources (e.g., base stations) to construct virtual wireless networks with minimal cost and slicing the selected resources to individual networks to optimally satisfy individual network demands. This problem is framed in a stochastic optimization framework and two approaches are presented for approximation. The first approach converts the framework into a deterministic equivalent and reduces it to a tractable form. The second approach uses a genetic algorithm to approximate resource selection. Approaches are simulated and evaluated utilizing a demand model constructed to emulate the statistics of an observed real world urban network. Simulations indicate that the first approach can provide a reasonably tight solution with significant time expense, and that the second approach provides a solution in significantly less time with the introduction of marginal error.
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Raffensperger, Peter Abraham. „Measuring and Influencing Sequential Joint Agent Behaviours“. Thesis, University of Canterbury. Electrical and Computer Engineering, 2013. http://hdl.handle.net/10092/7472.
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Algorithmically designed reward functions can influence groups of learning agents toward measurable desired sequential joint behaviours. Influencing learning agents toward desirable behaviours is non-trivial due to the difficulties of assigning credit for global success to the deserving agents and of inducing coordination. Quantifying joint behaviours lets us identify global success by ranking some behaviours as more desirable than others. We propose a real-valued metric for turn-taking, demonstrating how to measure one sequential joint behaviour. We describe how to identify the presence of turn-taking in simulation results and we calculate the quantity of turn-taking that could be observed between independent random agents. We demonstrate our turn-taking metric by reinterpreting previous work on turn-taking in emergent communication and by analysing a recorded human conversation. Given a metric, we can explore the space of reward functions and identify those reward functions that result in global success in groups of learning agents. We describe 'medium access games' as a model for human and machine communication and we present simulation results for an extensive range of reward functions for pairs of Q-learning agents. We use the Nash equilibria of medium access games to develop predictors for determining which reward functions result in turn-taking. Having demonstrated the predictive power of Nash equilibria for turn-taking in medium access games, we focus on synthesis of reward functions for stochastic games that result in arbitrary desirable Nash equilibria. Our method constructs a reward function such that a particular joint behaviour is the unique Nash equilibrium of a stochastic game, provided that such a reward function exists. This method builds on techniques for designing rewards for Markov decision processes and for normal form games. We explain our reward design methods in detail and formally prove that they are correct.
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Karaer, Arzu. „Optimum bit-by-bit power allocation for minimum distortion transmission“. Texas A&M University, 2005. http://hdl.handle.net/1969.1/4760.
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In this thesis, bit-by-bit power allocation in order to minimize mean-squared error (MSE) distortion of a basic communication system is studied. This communication system consists of a quantizer. There may or may not be a channel encoder and a Binary Phase Shift Keying (BPSK) modulator. In the quantizer, natural binary mapping is made. First, the case where there is no channel coding is considered. In the uncoded case, hard decision decoding is done at the receiver. It is seen that errors that occur in the more significant information bits contribute more to the distortion than less significant bits. For the uncoded case, the optimum power profile for each bit is determined analytically and through computer-based optimization methods like differential evolution. For low signal-to-noise ratio (SNR), the less significant bits are allocated negligible power compared to the more significant bits. For high SNRs, it is seen that the optimum bit-by-bit power allocation gives constant MSE gain in dB over the uniform power allocation. Second, the coded case is considered. Linear block codes like (3,2), (4,3) and (5,4) single parity check codes and (7,4) Hamming codes are used and soft-decision decoding is done at the receiver. Approximate expressions for the MSE are considered in order to find a near-optimum power profile for the coded case. The optimization is done through a computer-based optimization method (differential evolution). For a simple code like (7,4) Hamming code simulations show
that up to 3 dB MSE gain can be obtained by changing the power allocation on the
information and parity bits. A systematic method to find the power profile for linear block codes is also introduced given the knowledge of input-output weight enumerating function of the code. The information bits have the same power, and parity bits
have the same power, and the two power levels can be different.
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Cheng, Yong [Verfasser], Marius Akademischer Betreuer] Pesavento und Stefan [Akademischer Betreuer] [Ulbrich. „Joint Downlink Beamforming and Discrete Resource Allocation Using Mixed-Integer Programming / Yong Cheng. Betreuer: Marius Pesavento ; Stefan Ulbrich“. Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2014. http://nbn-resolving.de/urn:nbn:de:tuda-tuprints-37411.
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Cheng, Yong Verfasser], Marius [Akademischer Betreuer] Pesavento und Stefan [Akademischer Betreuer] [Ulbrich. „Joint Downlink Beamforming and Discrete Resource Allocation Using Mixed-Integer Programming / Yong Cheng. Betreuer: Marius Pesavento ; Stefan Ulbrich“. Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2014. http://d-nb.info/1108094309/34.
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Li, Y. „Resource allocation for coordinated multipoint joint transmission system and received signal strength based positioning in long term evolution network“. Thesis, University of Liverpool, 2017. http://livrepository.liverpool.ac.uk/3009494/.
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The Long-Term Evolution Advanced (LTE-A) system are expected to provide high speed and high quality services, which are supported by emerging technologies such as Coordinated Multipoint (CoMP) transmission and reception. Dynamic resource allocation plays a vital role in LTE-A design and planning, which is investigated in this thesis. In addition, Received Signal Strength (RSS) based positioning is also investigated in orthogonal frequency division multiplexing (OFDM) based wireless networks, which is based on an industry project. In the first contribution, a physical resource blocks (PRB) allocation scheme with fuzzy logic based user selection is proposed. This work considers three parameters and exploit a fuzzy logic (FL) based criterion to categorize users. As a result, it enhances accuracy of user classification. This work improves system capacity by a ranking based PRBs allocation schemes. Simulation results show that proposed fuzzy logic based user selection scheme improves performance for CoMP users. Proposed ranking based greedy allocation algorithm cut complexity in half but maintain same performance. In the second contribution, a two-layer proportional-fair (PF) user scheduling scheme is proposed. This work focused on fairness between CoMP and Non-CoMP users instead of balancing fairness in each user categories. Proposed scheme jointly optimizes fairness and system capacity over both CoMP and Non-CoMP users. Simulation results show that proposed algorithm significantly improves fairness between CoMP and Non-CoMP users. In the last contribution, RSS measurement method in LTE system is analyzed and a realizable RSS measurement method is proposed to fight against multipath effect. Simulation results shows that proposed method significantly reduced measurement error caused by multipath. In RSS based positioning area, this is the first work that consider exploiting LTE’s own signal strength measurement mechanism to enhance accuracy of positioning. Furthermore, the proposed method can be deployed in modern LTE system with limited cost.
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Eriksson, Anders. „Sektionsindelade gemensamhetsanläggningar : Om dess användning utifrån förrättningslantmätarens och ett rättsligt perspektiv“. Thesis, Högskolan i Gävle, Avdelningen för Industriell utveckling, IT och Samhällsbyggnad, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-22191.
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Samverkan mellan olika fastigheter kan vara centralt för att skapa ändamålsenliga fastigheter. Samverkan kan exempelvis ske genom bildandet av gemensamhetsanläggning bestående av väg som tillgodoser behov för flera fastigheter. När en gemensamhetsanläggning bildas ska kostnader för anläggningens utförande respektive drift fördelas genom andelstal. Ett andelstal kan avse hela gemensamhetsanläggningen eller del av gemensamhetsanläggningen. När olika andelstal avser olika delar av gemensamhetsanläggningen är gemensamhetsanläggningen sektionsindelad. Sektionsindelning är rent lagtekniskt möjligt men har lyfts fram som olämpligt i många sammanhang av flera källor, vilket gör det viktigt att studera. Syftet med denna studie var därför att beskriva användandet av sektionsindelning utifrån förrättningslantmätarens och ett rättsligt perspektiv. Studien syfte besvarades med hjälp av fyra frågeställningar. Frågeställningarna besvarades med hjälp av två metoder. För det första användes en juridisk metod där lagen, förarbeten, rättsfall och doktrin undersöktes. För det andra genomfördes en intervjustudie där sex förrättningslantmätare intervjuades. Resultatet från den juridiska metoden pekar på svårigheter i den senare förvaltningen som ett av huvudskälen till att sektionsindelning inte används i så stor utsträckning. Vägar är den typ av anläggning som sektionsindelning är mest lämplig för. Resultatet från intervjustudien visar att förrättningslantmätare i större utsträckning använder sektionsindelning för utförandeandelstalen än driftandelstalen. Samtidigt spelar ett antal faktorer in om sektionsindelning används eller inte som storleken på kostnader och relationen mellan de medverkade i gemensamhetsanläggningen. Samtidigt pekar resultat mot att sektionsindelning för olika kostnadsslag inte används i så stor utsträckning.Collaboration between different properties can be central for creating suitable properties. Collaboration may be through the creation of joint facilities that for example meets the real estates need of roads. Once formed the costs for a joint facilities operation and execution must be divided among its members. These costs are distributed through the awarding of "shared numbers" (andelstal). Shared numbers may refer to the whole joint facility or a part of the joint facility. When shared numbers refer to a part of the joint facility the facility is divided into sections, which is called sectiondivision. Sectiondivision is made possible by the way the law is formulated but has been highlighted as inappropriate in many contexts by multiple sources, making it important to study. The purpose of this study was to describe the use of sectiondivision based on cadastral surveyor’s perspective and a legal perspective. The purpose of this study was answered with the help of four questions. The questions were answered by two methods. Firstly, a legal method was used in which the law, preliminary work of the law, legal cases and doctrine was examined. Secondly, interviews where conducted with six cadastral surveyors. The results of the legal method indicate that difficulties in the latter management of the joint facility are one of the main reasons why sectiondivision should not be used as much. Roads are the type of facility that sectiondivision is most suitable for. The results from the interviews show that cadastral surveyors are making greater use of sections of execution than sections of operation. A number of factors are central for the use of sectiondivision. The size of the joint facility is one important factor. Another is the relations between the participants in the joint facility. Sectiondivision for different types of costs are not used in a wide extent.
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El, Omri Adel. „Cooperation in Supply Chains : Alliance Formation and Profit Allocation among Independent Firms“. Phd thesis, Ecole Centrale Paris, 2009. http://tel.archives-ouvertes.fr/tel-00453322.
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À l'ère de la mondialisation, l'environnement industriel et économique a subi plusieurs changements majeurs. Les chaînes logistiques sont en train de devenir de plus en plus de complexes réseaux composés de nombreux acteurs qui sont tantôt en concurrence et tantôt coopèrent pour répondre aux incessantes exigences des consommateurs. Dans un tel contexte, les entreprises se sont rapidement rendu compte de la limite du modèle complètement décentralisé où chacune d'entre elles optimise sa propre chaîne logistique indépendamment des autres acteurs. Afin de trouver de nouvelles sources de compétitivité et de faire face à la perpétuelle complexité de l'environnement économique, les entreprises tentent de dépasser la frontière des actions individuelles favorisant les actions coordonnées et centralisées. Désormais, la coopération entre les diverses chaînes logistiques et la formation d'alliances se trouvent au coeur des préoccupations des entreprises. En effet, en mutualisant les moyens logistiques, la coopération permet une meilleure exploitation des ressources et par le biais des actions collectives, elle permet de mieux bénéficier des économies d'échelles conduisant à réduire significativement les coûts et à générer des bénéfices considérables. Toutefois, dans de tels systèmes coopératifs, les acteurs sont indépendants et par ailleurs toujours intéressés en priorité par leurs profits individuels. De ce fait, la coopération soulève deux enjeux essentiels : (1) Quelles sont les alliances qui sont susceptibles de se former ? Et (2), comment partager les bénéfices réalisés sur les différents acteurs coopérants ? Dans cette thèse, nous nous intéressons au phénomène de la coopération dans les chaînes logistiques. Particulièrement, nous posons les précédentes questions dans des chaînes logistiques ou plusieurs firmes peuvent réduire leurs coûts logistiques en optant pour une gestion collective des stocks. Les principaux résultats de cette thèse portent sur l'utilisation des principes de la théorie des jeux coopératifs pour déterminer les alliances les plus profitables ainsi que la portion de profit que chaque firme doit recevoir afin de garder la stabilité des alliances formées.
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Hössinger, Reinhard, Florian Aschauer, Sergio Jara-Díaz, Simona Jokubauskaite, Basil Schmid, Stefanie Peer, Kay W. Axhausen und Regine Gerike. „A joint time-assignment and expenditure-allocation model: value of leisure and value of time assigned to travel for specific population segments“. Springer, 2019. http://dx.doi.org/10.1007/s11116-019-10022-w.
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Based on a time-use model with a sound theoretical basis and carefully collected data for
Austria, the value of leisure (VoL) for different population segments has been estimated.
Through the combination of these results with mode-specific values of travel time savings
from a related study based on the same data, the first mode-specific values of time assigned
to travel (VTAT) were calculated. Data was collected using a Mobility-Activity-Expenditure
Diary, a novel survey format which gathers all activities, expenditures, and travel decisions
from the same individuals for 1 week in a diary-based format. The average VoL is
8.17 Euro/h, which is below the mean wage of 12.14 Euro/h, indicating that the value of work is,
on average, negative. Regarding the reliability of the VoL, we show its sensitivity to the
variance of working time in a sample, something that has been ignored in previous studies
and could be used to avoid inadequate segmentation. We controlled this effect in the
analysis of the heterogeneity of the VoL across the population by estimating the parameters
from the total (unsegmented) dataset with single interaction terms. We find that the VTAT
is strictly negative for walking, predominantly negative for cycling and car, and predominantly
positive for public transport with 0.27 Euro/h on average. The positive VTAT for public
transport is a strong indication for the importance of travel conditions, in turn suggesting
that improvements in travel conditions of public transport might be as important as investing
in shorter travel times.
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Sharara, Mahdi. „Resource Allocation in Future Radio Access Networks“. Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPASG024.
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Cette thèse considère l'allocation des ressources radio et de calcul dans les futurs réseaux d'accès radio et plus précisément dans les réseaux Cloud-RAN (Cloud-Radio Access Networks) ainsi que les réseaux Open-RAN (Open-Radio Access Networks). Dans ces architectures, le traitement en bande de base de plusieurs stations de base est centralisé et virtualisé. Cela permet une meilleure optimisation du réseau et une réduction des dépenses d'investissement et d'exploitation. Dans la première partie de cette thèse, nous considérons un schéma de coordination entre les ordonnanceurs radio et de calcul. Dans le cas où les ressources de calcul ne sont pas suffisantes, l'ordonnanceur de calcul envoie un retour d'information à l'ordonnanceur radio pour mettre à jour les paramètres radio. Bien que cela réduise le débit radio de l'utilisateur, il garantit que la trame sera traitée au niveau de l'ordonnanceur de calcul. Nous modélisons ce schéma de coordination à l'aide de la programmation linéaire en nombres entiers (ILP) avec comme objectifs de maximiser le débit total ainsi que la satisfaction des utilisateurs. Les résultats montrent la capacité de ce schéma de coordination à améliorer différents paramètres, notamment la réduction du gaspillage de puissance de transmission. Ensuite, nous proposons des heuristiques à faible complexité et nous les testons dans un environnement de services multiples avec des exigences différentes. Dans la deuxième partie de cette thèse, nous considérons l'allocation conjointe des ressources radio et de calcul. Les ressources radio et de calcul sont allouées conjointement dans le but de minimiser la consommation énergétique. Le problème est modélisé à l'aide de la programmation linéaire mixte en nombres entiers (MILP), et est ensuite comparé à un autre problème MILP ayant comme objectif de maximiser le débit total. Les résultats montrent que l'allocation conjointe des ressources radio et de calcul est plus efficace que l'allocation séquentielle pour minimiser la consommation énergétique. Enfin, nous proposons un algorithme basé sur la théorie de matching (matching theory) à faible complexité qui pourra être une alternative pour résoudre le problème MILP à haute complexité. Dans la dernière partie de cette thèse, nous étudions l'utilisation des outils de l'apprentissage machine (machine learning). Tout d'abord, nous considérons un modèle d'apprentissage profond (deep learning) qui vise à apprendre comment résoudre le problème de coordination ILP, mais en un temps beaucoup plus court. Ensuite, nous considérons un modèle d'apprentissage par renforcement (reinforcement learning) qui vise à allouer des ressources de calcul aux utilisateurs afin de maximiser le profit de l'opérateurThis dissertation considers radio and computing resource allocation in future radio access networks and more precisely Cloud Radio Access Network (Cloud-RAN) and Open Radio Access Network (Open-RAN). In these architectures, the baseband processing of multiple base stations is centralized and virtualized. This permits better network optimization and allows for saving capital expenditure and operational expenditure. In the first part, we consider a coordination scheme between radio and computing schedulers. In case the computing resources are not sufficient, the computing scheduler sends feedback to the radio scheduler to update the radio parameters. While this reduces the radio throughput of the user, it guarantees that the frame will be processed at the computing scheduler level. We model this coordination scheme using Integer Linear Programming (ILP) with the objectives of maximizing the total throughput and users' satisfaction. The results demonstrate the ability of this scheme to improve different parameters, including the reduction of wasted transmission power. Then, we propose low-complexity heuristics, and we test them in an environment of multiple services with different requirements. In the second part, we consider the joint radio and computing resource allocation. Radio and computing resources are jointly allocated with the aim of minimizing energy consumption. The problem is modeled as a Mixed Integer Linear Programming Problem (MILP) and is compared to another MILP problem that maximizes the total throughput. The results demonstrate the ability of joint allocation to minimize energy consumption in comparison with the sequential allocation. Finally, we propose a low-complexity matching game-based algorithm that can be an alternative for solving the high-complexity MILP problem. In the last part, we investigate the usage of machine learning tools. First, we consider a deep learning model that aims to learn how to solve the coordination ILP problem, but with a much shorter time. Then, we consider a reinforcement learning model that aims to allocate computing resources for users to maximize the operator's profit
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Calabuig, Soler Daniel. „Common Radio Resource Management Strategies for Quality of Service Support in Heterogeneous Wireless Networks“. Doctoral thesis, Universitat Politècnica de València, 2010. http://hdl.handle.net/10251/7348.
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Hoy en día existen varias tecnologías que coexisten en una misma zona formando un sistema heterogéneo. Además, este hecho se espera que se vuelva más acentuado con todas las nuevas tecnologías que se están estandarizando actualmente. Hasta ahora, generalmente son los usuarios los que eligen la tecnología a la que se van a conectar, ya sea configurando sus terminales o usando terminales distintos. Sin embargo, esta solución es incapaz de aprovechar al máximo todos los recursos. Para ello es necesario un nuevo conjunto de estrategias. Estas estrategias deben gestionar los recursos radioeléctricos conjuntamente y asegurar la satisfacción de la calidad de servicio de los usuarios.
Siguiendo esta idea, esta Tesis propone dos nuevos algoritmos. El primero es un algoritmo de asignación dinámica de recusos conjunto (JDRA) capaz de asignar recursos a usuarios y de distribuir usuarios entre tecnologías al mismo tiempo. El algoritmo está formulado en términos de un problema de optimización multi-objetivo que se resuelve usando redes neuronales de Hopfield (HNNs). Las HNNs son interesantes ya que se supone que pueden alcanzar soluciones sub-óptimas en cortos periodos de tiempo. Sin embargo, implementaciones reales de las HNNs en ordenadores pierden esta rápida respuesta. Por ello, en esta Tesis se analizan las causas y se estudian posibles mejoras.
El segundo algoritmo es un algoritmo de control de admisión conjunto (JCAC) que admite y rechaza usuarios teniendo en cuenta todas las tecnologías al mismo tiempo. La principal diferencia con otros algorimos propuestos es que éstos últimos toman las dicisiones de admisión en cada tecnología por separado. Por ello, se necesita de algún mecanismo para seleccionar la tecnología a la que los usuarios se van a conectar. Por el contrario, la técnica propuesta en esta Tesis es capaz de tomar decisiones en todo el sistema heterogéneo. Por lo tanto, los usuarios no se enlazan con ninguna tecnología antes de ser admitidos.Calabuig Soler, D. (2010). Common Radio Resource Management Strategies for Quality of Service Support in Heterogeneous Wireless Networks [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/7348
Palancia
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Salazar, Gabriel R. „An analysis of the role of the Joint Chiefs of Staff in the requirements generation and resource allocation process within the Department of Defense“. Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA311436.
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Bao, Lei. „Control over Low-Rate Noisy Channels“. Doctoral thesis, KTH, Kommunikationsteori, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10641.
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Networked embedded control systems are present almost everywhere. A recent trendis to introduce radio communication in these systems to increase mobility and flex-ibility. Network nodes, such as the sensors, are often simple devices with limitedcomputing and transmission power and low storage capacity, so an important prob-lem concerns how to optimize the use of resources to provide sustained overall sys-tem performance. The approach to this problem taken in the thesis is to analyzeand design the communication and control application layers in an integrated man-ner. We focus in particular on cross-layer design techniques for closed-loop controlover non-ideal communication channels, motivated by future control systems withvery low-rate and highly quantized sensor communication over noisy links. Severalfundamental problems in the design of source–channel coding and optimal controlfor these systems are discussed.The thesis consists of three parts. The first and main part is devoted to the jointdesign of the coding and control for linear plants, whose state feedback is trans-mitted over a finite-rate noisy channel. The system performance is measured by afinite-horizon linear quadratic cost. We discuss equivalence and separation proper-ties of the system, and conclude that although certainty equivalence does not holdin general it can still be utilized, under certain conditions, to simplify the overalldesign by separating the estimation and the control problems. An iterative opti-mization algorithm for training the encoder–controller pairs, taking channel errorsinto account in the quantizer design, is proposed. Monte Carlo simulations demon-strate promising improvements in performance compared to traditional approaches.In the second part of the thesis, we study the rate allocation problem for statefeedback control of a linear plant over a noisy channel. Optimizing a time-varyingcommunication rate, subject to a maximum average-rate constraint, can be viewedas a method to overcome the limited bandwidth and energy resources and to achievebetter overall performance. The basic idea is to allow the sensor and the controllerto communicate with a higher data rate when it is required. One general obstacle ofoptimal rate allocation is that it often leads to a non-convex and non-linear problem.We deal with this challenge by using high-rate theory and Lagrange duality. It isshown that the proposed method gives a good performance compared to some otherrate allocation schemes.In the third part, encoder–controller design for Gaussian channels is addressed.Optimizing for the Gaussian channel increases the controller complexity substan-tially because the channel output alphabet is now infinite. We show that an efficientcontroller can be implemented using Hadamard techniques. Thereafter, we proposea practical controller that makes use of both soft and hard channel outputs.QC 20100623
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Chenghua, Lin. „Probabilistic topic models for sentiment analysis on the Web“. Thesis, University of Exeter, 2011. http://hdl.handle.net/10036/3307.
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Sentiment analysis aims to use automated tools to detect subjective information such as opinions, attitudes, and feelings expressed in text, and has received a rapid growth of interest in natural language processing in recent years. Probabilistic topic models, on the other hand, are capable of discovering hidden thematic structure in large archives of documents, and have been an active research area in the field of information retrieval. The work in this thesis focuses on developing topic models for automatic sentiment analysis of web data, by combining the ideas from both research domains. One noticeable issue of most previous work in sentiment analysis is that the trained classifier is domain dependent, and the labelled corpora required for training could be difficult to acquire in real world applications. Another issue is that the dependencies between sentiment/subjectivity and topics are not taken into consideration. The main contribution of this thesis is therefore the introduction of three probabilistic topic models, which address the above concerns by modelling sentiment/subjectivity and topic simultaneously. The first model is called the joint sentiment-topic (JST) model based on latent Dirichlet allocation (LDA), which detects sentiment and topic simultaneously from text. Unlike supervised approaches to sentiment classification which often fail to produce satisfactory performance when applied to new domains, the weakly-supervised nature of JST makes it highly portable to other domains, where the only supervision information required is a domain-independent sentiment lexicon. Apart from document-level sentiment classification results, JST can also extract sentiment-bearing topics automatically, which is a distinct feature compared to the existing sentiment analysis approaches. The second model is a dynamic version of JST called the dynamic joint sentiment-topic (dJST) model. dJST respects the ordering of documents, and allows the analysis of topic and sentiment evolution of document archives that are collected over a long time span. By accounting for the historical dependencies of documents from the past epochs in the generative process, dJST gives a richer posterior topical structure than JST, and can better respond to the permutations of topic prominence. We also derive online inference procedures based on a stochastic EM algorithm for efficiently updating the model parameters. The third model is called the subjectivity detection LDA (subjLDA) model for sentence-level subjectivity detection. Two sets of latent variables were introduced in subjLDA. One is the subjectivity label for each sentence; another is the sentiment label for each word token. By viewing the subjectivity detection problem as weakly-supervised generative model learning, subjLDA significantly outperforms the baseline and is comparable to the supervised approach which relies on much larger amounts of data for training. These models have been evaluated on real world datasets, demonstrating that joint sentiment topic modelling is indeed an important and useful research area with much to offer in the way of good results.
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Zheng, Shuo. „Prise en compte des contraintes de canal dans les schémas de codage vidéo conjoint du source-canal“. Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLT005/document.
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Les schémas de Codage Vidéo Linéaire (CVL) inspirés de SoftCast ont émergé dans la dernière décennie comme une alternative aux schémas de codage vidéo classiques. Ces schémas de codage source-canal conjoint exploitent des résultats théoriques montrant qu’une transmission (quasi-)analogique est plus performante dans des situations de multicast que des schémas numériques lorsque les rapports signal-à-bruit des canaux (C-SNR) diffèrent d’un récepteur à l’autre. Dans ce contexte, les schémas de CVL permettent d’obtenir une qualité de vidéo décodée proportionnelle au C-SNR du récepteur.Une première contribution de cette thèse concerne l’optimisation de la matrice de précodage de canal pour une transmission de type OFDM de flux générés par un CVL lorsque les contraintes de puissance diffèrent d’un sous-canal à l’autre. Ce type de contrainte apparait en sur des canaux DSL, ou dans des dispositifs de transmission sur courant porteur en ligne (CPL). Cette thèse propose une solution optimale à ce problème de type multi-level water filling et nécessitant la solution d’un problème de type Structured Hermitian Inverse Eigenvalue. Trois algorithmes sous-optimaux de complexité réduite sont également proposés. Des nombreux résultats de simulation montrent que les algorithmes sous-optimaux ont des performances très proches de l’optimum et réduisent significativement le temps de codage. Le calcul de la matrice de précodage dans une situation de multicast est également abordé. Une seconde contribution principale consiste en la réduction de l’impact du bruit impulsif dans les CVL. Le problème de correction du bruit impulsif est formulé comme un problème d’estimation d’un vecteur creux. Un algorithme de type Fast Bayesian Matching Pursuit (FBMP) est adapté au contexte CVL. Cette approche nécessite de réserver des sous-canaux pour la correction du bruit impulsif, entrainant une diminution de la qualité vidéo en l'absence de bruit impulsif. Un modèle phénoménologique (MP) est proposé pour décrire l’erreur résiduelle après correction du bruit impulsif. Ce modèle permet de d’optimiser le nombre de sous-canaux à réserver en fonction des caractéristiques du bruit impulsif. Les résultats de simulation montrent que le schéma proposé améliore considérablement les performances lorsque le flux CVL est transmis sur un canal sujet à du bruit impulsifSoftCast based Linear Video Coding (LVC) schemes have been emerged in the last decade as a quasi analog joint-source-channel alternative to classical video coding schemes. Theoretical analyses have shown that analog coding is better than digital coding in a multicast scenario when the channel signal-to-noise ratios (C-SNR) differ among receivers. LVC schemes provide in such context a decoded video quality at different receivers proportional to their C-SNR.This thesis considers first the channel precoding and decoding matrix design problem for LVC schemes under a per-subchannel power constraint. Such constraint is found, e.g., on Power Line Telecommunication (PLT) channels and is similar to per-antenna power constraints in multi-antenna transmission system. An optimal design approach is proposed, involving a multi-level water filling algorithm and the solution of a structured Hermitian Inverse Eigenvalue problem. Three lower-complexity alternative suboptimal algorithms are also proposed. Extensive experiments show that the suboptimal algorithms perform closely to the optimal one and can reduce significantly the complexity. The precoding matrix design in multicast situations also has been considered.A second main contribution consists in an impulse noise mitigation approach for LVC schemes. Impulse noise identification and correction can be formulated as a sparse vector recovery problem. A Fast Bayesian Matching Pursuit (FBMP) algorithm is adapted to LVC schemes. Subchannels provisioning for impulse noise mitigation is necessary, leading to a nominal video quality decrease in absence of impulse noise. A phenomenological model (PM) is proposed to describe the impulse noise correction residual. Using the PM model, an algorithm to evaluate the optimal number of subchannels to provision is proposed. Simulation results show that the proposed algorithms significantly improve the video quality when transmitted over channels prone to impulse noise
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Johansson, Mats. „Product Costing for Sawmill Business Management“. Doctoral thesis, Växjö : Växjö University Press, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-1566.
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Zhao, Haiquan. „Measurement and resource allocation problems in data streaming systems“. Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34785.
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In a data streaming system, each component consumes one or several streams of data on the fly and produces one or several streams of data for other components. The entire Internet can be viewed as a giant data streaming system. Other examples include real-time exploratory data mining and high performance transaction processing. In this thesis we study several measurement and resource allocation optimization problems of data streaming systems.
Measuring quantities associated with one or several data streams is often challenging because the sheer volume of data makes it impractical to store the streams in memory or ship them across the network. A data streaming algorithm processes a long stream of data in one pass using a small working memory (called a sketch). Estimation queries can then be answered from one or more such sketches. An important task is to analyze the performance guarantee of such algorithms. In this thesis we describe a tail bound problem that often occurs and present a technique for solving it using majorization and convex ordering theories. We present two algorithms that utilize our technique. The first is to store a large array of counters in DRAM while achieving the update speed of SRAM. The second is to detect global icebergs across distributed data streams.
Resource allocation decisions are important for the performance of a data streaming system. The processing graph of a data streaming system forms a fork and join network. The underlying data processing tasks consists of a rich set of semantics that include synchronous and asynchronous data fork and data join. The different types of semantics and processing requirements introduce complex interdependence between various data streams within the network. We study the distributed resource allocation problem in such systems with the goal of achieving the maximum total utility of output streams. For networks with only synchronous fork and join semantics, we present several decentralized iterative algorithms using primal and dual based optimization techniques. For general networks with both synchronous and asynchronous fork and join semantics, we present a novel modeling framework to formulate the resource allocation problem, and present a shadow-queue based decentralized iterative algorithm to solve the resource allocation problem. We show that all the algorithms guarantee optimality and demonstrate through simulation that they can adapt quickly to dynamically changing environments.
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Ouro-Bodi, Ouro-Gnaou. „Les Etats et la protection internationale de l'environnement : la question du changement climatique“. Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0228/document.
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Le changement climatique est devenu aujourd’hui le fléau environnemental qui préoccupe etmobilise le plus la communauté internationale. L’aboutissement de cette mobilisation générale reste sansdoute la mise en place du régime international de lutte contre le changement climatique dont la Conventioncadredes Nations Unies sur le changement climatique et le Protocole de Kyoto constituent les basesjuridiques. Ce régime innove en ce qu’il fixe des engagements quantifiés de réduction des émissions de gaz àeffet de serre pour les États pollueurs, mais aussi en ce qu’il instaure des mécanismes dits de « flexibilité »dont la mise en oeuvre est assortie d’un contrôle original basé sur un Comité dit de « l’observance ». Mais, endépit de toute cette production normative, il est regrettable de constater aujourd’hui que le régimeinternational du climat est un véritable échec. En effet, si la mobilisation des États ne fait aucun doute, enrevanche, les mêmes États qui ont volontairement accepté de s’engager refusent délibérément d’honorer leursengagements pour des raisons essentiellement politiques, économiques et stratégiques. Ce travail ambitionnedonc de lever le voile sur les causes de cet échec en dressant un bilan mitigé de la première périoded’engagement de Kyoto qui a pris fin en 2012, et propose des perspectives pour un régime juridique duclimat post-Kyoto efficient et efficace, en mesure d’être à la hauteur des enjeuxClimate change has become the scourge environmental concern and mobilizes more theinternational community. The outcome of this mobilization remains probably the implementation ofinternational climate change regime for which the Climate Convention and the Kyoto Protocol are the legalbases. This system is innovative in that it sets quantified emission reduction commitments for greenhouse gasemissions (GHG) for polluters States, but also in that it establishes mechanisms known as of “flexibility”whose implementation is accompanied by a control based on a Committee known as of “compliance”. Butdespite all this normative production, it is regrettable that today the international climate regime is a realfailure. Indeed, if the mobilization of states is no doubt, however, the same states that have voluntarily agreedto engage deliberately refuse to honour their commitments for essentially political, economic and strategicreasons. This work therefore aims to shed light on the causes of this failure by developing a mixed record ofthe first Kyoto commitment ended period in 2012, and offers prospects for a legal regime of the post-Kyotoclimate and efficient, able to be up to the challenges
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LAI, ZHAO-MING, und 賴昭明. „A study on joint clearances and feasible joint allocation in spherical four-bar linkages“. Thesis, 1990. http://ndltd.ncl.edu.tw/handle/33308620992187550740.
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Gong, Xiaowen. „Joint bandwidth and power allocation in wireless communication networks“. Master's thesis, 2010. http://hdl.handle.net/10048/1251.
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This thesis consists of two studies on joint bandwidth and power allocation strategy for wireless communication
networks. In the first study, joint bandwidth and power allocation strategy is proposed for wireless multi-user networks without relaying and with decode-and-forward relaying. It is shown that the formulated resource allocation problems are convex and, thus, can be solved efficiently. Admission control problem based on the joint bandwidth and power allocation strategy is further considered, and a greedy search algorithm is developed for solving it efficiently. In the second study, joint bandwidth
and power allocation strategy is presented for maximizing the sum ergodic capacity of secondary users under fading channels in cognitive radio networks. Optimal bandwidth allocation is derived in closed-form for any given power allocation. Then the structures of optimal power allocations are derived. Using these structures, efficient algorithms are developed for finding the optimal power allocations.Communications
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Lee, Chiao, und 李橋. „Joint Subcarrier Allocation and Power Control for OFDMA Femtocells“. Thesis, 2010. http://ndltd.ncl.edu.tw/handle/23589213494115005605.
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Chao, Li-Hua, und 趙梨華. „Joint Spectrum Allocation and Transmission Opportunity for Cognitive Radio Networks“. Thesis, 2010. http://ndltd.ncl.edu.tw/handle/21191417189356437377.
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碩士國立交通大學
資訊科學與工程研究所
99
There are three main operator types and research subjects in cognitive radio systems, consisting of software define radio (SDR), channel sensing and channel management. In this paper, we focus on a channel-sensing and accessing and a synchronized channel-sensing and accessing for cognitive radio users in IEEE 802.11 wireless networks is proposed. The mechanism consists of two phases: fast channel sensing and channel vacating. A pair of cognitive radio users can search an available channel with the most success transmission probability from those available channels presently and further proceed to transmit data by fast channel sensing time-efficiently; proactive channel vacating is for the pair of cognitive radio users to be aware of the presence of primary users and vacate the occupied channel as quick as possible. We utilize the concept of channel hopping to reduce the average channel sensing time of cognitive radio users. Besides, we propose one equation to decide how to set TXQ (the bounded time interval during which a CR user can send as many frames as possible) by PU traffic load and make the caused interference to primary users within tolerable range. We further evaluate the performance of a considered cognitive radio network through simulations. From the simulation results, our proposed protocol can efficiently balance the tradeoff between throughput performance of a cognitive radio network and waiting time of primary users.
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Liao, Jia-Jian, und 廖家健. „An Adaptive Joint Bandwidth Allocation Scheme for Heterogeneous Wireless Networks“. Thesis, 2010. http://ndltd.ncl.edu.tw/handle/25082999259840068857.
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碩士國立東華大學
網路與多媒體科技研究所
98
With advanced network technology, now people may connect with different networks at the same time or same place. Hence, IEEE published 1900.4 standards in February 2009, which provided integration architecture for heterogeneous network. In this thesis, we enact standards for data transmission between core network and mobile devices. Also, we use common radio resource management architecture to integrate network environment and achieve optimal resource distribution. Wireless network resource distribution is an important issue. In this thesis, we propose a model with user mobility prediction algorithm, which considers the coverage of base stations and mobility of pedestrians, vehicles, and mass transportation for bandwidth reservation. In addition, we use the concept of bandwidth integration to access to various BSs and achieve optimal goals in heterogeneous network environment. This thesis adopted hybrid genetic algorithm, which combines traditional genetic Algorithm and local search to improve the frequency of finding Pareto set. The performance of our algorithm is compared to three other algorithms in order to verify the effectiveness of the proposed work. The simulation result shows that our mechanism can provide optimal network utilization and stable quality in the multi-homed environment.
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Tsou, Yao-Chun, und 鄒曜駿. „Joint Clusterization and Power Allocation for Cloud Radio Access Network“. Thesis, 2015. http://ndltd.ncl.edu.tw/handle/57398476295819895668.
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碩士國立交通大學
電信工程研究所
104
In this paper, the cloud radio access network (C-RAN) is considered to extend the transmission coverage via the distributed deployment of large scale remote radio units (RRUs). The benefits of C-RAN system deployment is distributed network with centralized management solution. The RRUs are more closer to the user equipments (UEs), power consumption can be reduced to overcome pathloss attenuation and enhance spectral and energy efficiency (EE). However, this type of structure can induce considerable computational loadings due to the centralized management mechanisms. To reduce the complexity incurred in the C-RAN architecture, the clusterization technique is designed to categorize those RRUs into several groups. For the purpose of enhancing EE as well as the consideration of computational complexity, the joint clusterization and power allocation schemes are proposed to obtain the better tradeoff under the quality-of-service (QoS) requirement for each UE. The optimization problem is modeled as mixed combinatorial problem. To obtain the near-optimal solution without any problem transformation, the stochastic joint clusterization and power allocation (S-JCPA) scheme is proposed to jointly solve the problem with cross-entropy (CE) algorithm. In addition, reducing the complexity incurs from stochastic process, the deterministic joint clusterization and power allocation (D-JCPA) schemes are also proposed. By converting the problem into convex problem and using derivation information to find the clusterization and power allocation policies. Moreover, this joint optimization problem can be divided into two sub-problems, each of which is solved by iterative algorithm. Therefore, the iterative times in D-JCPA scheme can be reduced. In addition, as large number of RRUs are deployed in the C-RAN system, the large random theorem with convex properties can be applied to derive asymptotic form for performing D-JCPA scheme. Finally, the complexity of the proposed method has been analyzed. Simulation results show that the proposed algorithms can provide better performance gain than the existing method.
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Tang, Chih-Hsiang, und 湯智翔. „Joint Relay Selection and Resource Allocation using Cooperative Network Coding“. Thesis, 2010. http://ndltd.ncl.edu.tw/handle/89792273448231442248.
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碩士臺灣大學
電信工程學研究所
98
The increasing rate on ubiquitous wireless broadband access drives the development of even better wireless communication technology. Both LTE-Advanced and 802.16m, potential candidates of so-called 4G standard, are capable of reaching over-the-air 1Gbps transmission rate which is required by IMT-Advanced. Although different in certain features, they both share many common key technologies, including OFDMA, MIMO, multi-carrier, relay support, etc. Relay operation is viewed as a highly efficient way to either increase cell coverage or enhance channel condition without deployment of a new BS. However, without proper setting and better way of transmission, relay operation might not be as good as expected. Cooperative communication is a promising communication technology developed in recent years. While it might not be possible for MS node to be equipped with several antennas, as MIMO requested, cooperative communication forms a virtual MIMO scheme through the cooperation with neighbor nodes. Theoretically proven, cooperative communication could not only increase system capacity, but enhance reliability. Network coding is another promising technology that attracts many researches. To encode receiving packets by XOR operation, network coding could largely reduce transmission time, so as to increase system throughput. In virtue of the above reasons, we try to combine cooperative communication with network coding and apply this new mechanism to cellular relay system. Cooperative network coding (CNC) for relay system generates challenging problems, among which relay selection might be the most important one. How to choose relay station (RS) to incorporate CNC remains a difficult problem. In the following article, we use relay station and RS alternately. Moreover, this work is highly associated with resource allocation problem. Hence, we propose a joint relay selection and resource allocation problem with precise formulation. Then, an algorithm is proposed to minimize the computation of original optimization problems. Finally, through computer simulation, results show that our work increase overall system capacity by a large degree.
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Chang, Wen-Yao, und 張文耀. „A Joint Multicast Scheduling and Power Allocation Scheme for Cellular Systems“. Thesis, 2013. http://ndltd.ncl.edu.tw/handle/39347511015976740566.
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碩士國立臺灣大學
電信工程學研究所
101
Due to the nature of time-varying and frequency selective fading, wireless communication system can increase system throughput via dynamic resource allocation (time slot, bandwidth, power and bit), exploiting multi-user diversity. Multicast deliver the same content to several users in the same group to enhance frequency efficiency, but the channel conditions may vary greatly between users of the same group. Conventional approach selects the worst channel gain as equivalent channel gain of group’s sub-channel, limiting the system throughput. Aim to maximum frequency efficiency, we have to make appropriate trade-off between multi-user diversity gain and multicast gain. In addition to system throughput, fairness is another performance index of resource allocation. Considering orthogonal frequency division multiple access (OFDMA)-based wireless multicast system, firstly, we separately formulate different resource allocation as three simpler optimization problem — Link adaption of single group (Which data fragments can be correctly received by different users?), sub-channel assignment (Which group’s data can be transmitted over different sub-channels?) and power allocation — and propose corresponding algorithms successively. Subsequently, we formulate all resource allocation as a joint optimization problem and combine it with aforementioned algorithms to approach proportional fairness among users. Besides, we also consider more general case — One user may belong to more than two different groups (i.e., receives different data streams more than two simultaneously). Simulation results show that our proposed approaches have outer performance on system throughput as well as fairness among users.
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Cheng, Yong. „Joint Downlink Beamforming and Discrete Resource Allocation Using Mixed-Integer Programming“. Phd thesis, 2014. https://tuprints.ulb.tu-darmstadt.de/3741/1/Joint%20Downlink%20Beamforming%20and%20Discrete%20Resource%20Allocation%20Using%20Mixed-Integer%20Programming.pdf.
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Multi-antenna processing is widely adopted as one of the key enabling technologies for current and future cellular networks. Particularly, multiuser downlink beamforming (also known as space-division multiple access), in which multiple users are simultaneously served with spatial transmit beams in the same time and frequency resource, achieves high spectral efficiency with reduced energy consumption. To harvest the potential of multiuser downlink beamforming in practical systems, optimal beamformer design shall be carried out jointly with network resource allocation. Due to the specifications of cellular standards and/or implementation constraints, resource allocation in practice naturally necessitates discrete decision makings, e.g., base station (BS) association, user scheduling and admission control, adaptive modulation and coding, and codebook-based beamforming (precoding).
This dissertation focuses on the joint optimization of multiuser downlink beamforming and discrete resource allocation in modern cellular networks. The problems studied in this thesis involve both continuous and discrete decision variables and are thus formulated as mixed-integer programs (MIPs). A systematic MIP framework is developed to address the problems. The MIP framework consists of four components: (i) MIP formulations that support the commercial solver based approach for computing the optimal solutions, (ii) analytic comparisons of the MIP formulations, (iii) customizing techniques for speeding up the MIP solvers, and (iv) low-complexity heuristic algorithms for practical applications.
We consider first joint network topology optimization and multi-cell downlink beamforming (JNOB) for coordinated multi-point transmission. The objective is to minimize the overall power consumption of all BSs while guaranteeing the quality-of-service (QoS) requirements of the mobile stations (MSs). A standard mixed-integer second-order cone program (MISOCP) formulation and an extended MISOCP formulation are developed, both of which support the branch-and-cut (BnC) method. Analysis shows that the extended formulation admits tighter continuous relaxations (and hence less computational complexity) than that of the standard formulation. Effective strategies are proposed to customize the BnC method in the MIP solver CPLEX when applying it to the JNOB problem. Low-complexity inflation and deflation procedures are devised for large-scale applications. The simulations show that our design results in sparse network topologies and partial BS cooperation.
We study next the joint optimization of discrete rate adaptation and downlink beamforming (DRAB), in which rate adaptation is carried out via modulation and coding scheme (MCS) assignment and admission control is embedded in the MCS assignment procedure. The objective is to achieve the maximum sum-rate with the minimum transmitted BS power. As in the JNOB problem, a standard and an extended MISOCP formulations are developed, and analytic comparisons of the two formulations are carried out. The analysis also leads to efficient customizing strategies for the BnC method in CPLEX. We also develop fast inflation and deflation procedures for applications in large-scale networks. Our numerical results show that the heuristic algorithms yield sum-rates that are very close to the optimal ones.
We then turn our attention to codebook-based downlink beamforming. Codebook-based beamforming is employed in the latest cellular standards, e.g., in long-term evolution advanced (LTE-A), to simplify the signaling procedure of beamformers with reduced signaling overhead. We consider first the standard codebook-based downlink beamforming (SCBF) problem, in which precoding vector assignment and power allocation are jointly optimized. The objective is to minimize the total transmitted BS power while ensuring the prescribed QoS targets of the MSs. We introduce a virtual uplink (VUL) problem, which is proved to be equivalent to the SCBF problem. A customized power iteration method is developed to solve optimally the VUL problem and hence the SCBF problem. To improve the performance of codebook-based downlink beamforming, we propose a channel predistortion mechanism that does not introduce any additional signalling overhead or require modification of the mobile receivers. The joint codebook-based downlink beamforming and channel predistortion (CBCP) problem represents a non-convex MIP. An alternating optimization algorithm and an alternating feasibility search algorithm are devised to approximately solve the CBCP problem. The simulation results confirm the efficiency of the channel predistortion scheme, e.g., achieving significant reductions of the total transmitted BS power.
We study finally the worst-case robust codebook-based downlink beamforming when only estimated channel covariance matrices are available at the BS. Similar to the DRAB problem, user admission control is embedded in the precoding vector assignment procedure. In the robust codebook-based downlink beamforming and admission control (RCBA) problem, the objective is to achieve the maximum number of admitted MSs with the minimum transmitted BS power. We develop a conservative mixed-integer linear program (MILP) approximation and an exact MISOCP formulation of the RCBA problem. We further propose a low-complexity inflation procedure. Our simulations show that the three approaches yield almost the same average number of admitted MSs, while the MILP based approach requires much more transmitted BS power than the other two to support the admitted MSs.
The MIP framework developed in this thesis can be applied to address various discrete resource allocation problems in interference limited cellular networks. Both optimal solutions, i.e., performance benchmarks, and low-complexity practical algorithms are considered in our MIP framework. Conventional approaches often did not adopt the exact discrete models and approximated the discrete variables by (quantized) continuous ones, which could lead to highly suboptimal solutions or infeasible problem instances.
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Shu-Wei, Fu. „Nestling sex allocation of a joint-nesting Yuhina brunneiceps population at Meifeng“. 2005. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2507200514393800.
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Fu, Shu-Wei, und 傅淑瑋. „Nestling sex allocation of a joint-nesting Yuhina brunneiceps population at Meifeng“. Thesis, 2005. http://ndltd.ncl.edu.tw/handle/99283626266780323945.
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碩士國立臺灣大學
森林環境暨資源學研究所
93
The aim of this study was to examine the nestling sex allocation of a joint-nesting population of Taiwan yuhina (Yuhina brunneiceps). Most of Taiwan Yuhina breeds with joint-nesting strategy in the study site, and the linear hierarchy relationship within group members is obvious. Dominant males had larger wing chords than subordinate males, but there was no difference of body size between dominant and subordinate females. We assumed that the condition of males was more influenced by parental investment than that of females. I conducted the study at Meifeng area during 2003-2004; field work included observing the hierarchy and pair bond of breeding group members, and taking the blood samples from adults and nestlings. I then employed molecular techniques to determine the sex and estimate parentage of nestlings. Results showed that nestling sex was associated with maternal status, and dominant females produced more sons than subordinate females. When sex ratio of broods was analyzed, I found that primary sex ratio was influenced by timing of breeding season, group size, and brood size. The proportion of sons decreased as the season progressed and when group size and brood size were larger. Secondary sex ratio was also influenced by timing of breeding season and brood size. The results supported the predictions of Trivers and Willard hypothesis, females manipulated offspring sex in relation to maternal status and sex ratio of broods was female-biased when the resources was limited in late breeding season and when brood size was larger.
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Yang, Jia-you, und 楊佳祐. „Joint Beamforming and Power Allocation Design in Non-Orthogonal Multiple Access Systems“. Thesis, 2015. http://ndltd.ncl.edu.tw/handle/09374400561877072556.
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碩士國立中山大學
通訊工程研究所
103
Due to the rapid development of communication networks, people gradually increasingly rely on mobile communication devices in their daily life, resulting in increasing demand for network bandwidth and transmission rate.To satisfy serve requirement, mobile communications have developed toward the fourth generation systems. In the near future, the Fifth-generation mobile communications network which is expected to boost thousands times of capacity will be deployed in 2020. To deal with explosion amount of data transmission, 5G systems aim to enhance spectrum efficiency, network capacity, transmission rate, and reduce latency in the future. Non-orthogonal multiple access (NOMA) technique is one of key candidates currently. Multi-accepting technologies mostly allocate orthogonal radio resourced multiple users in time-domain, frequency domain, or code domain. By contrast, NOMA technology allows users access and share the same radio resource through multiple-access in power domain in order to effectively improve spectrum efficiency. In this paper, we consider a multi-input multi-output (MIMO) down-link system where using non-orthogonal multiple access technology is adopted.The base station uses superposition coding to superimpose signals regarding multiple users. We propose to optimize the transmission of a MIMO base station toward multiple users equipped with antenna based on perfect channel state information. The user can use successive interference cancellation to enhance the signal and interference plus noise ratio. We will design the beamforming vector of the base station as well as the optimal power allocation of downlink users, in order to maximize sum rate of the downlink system. In this paper, we consider two beamforming strategies, one is to match the beamforming vector to the stronger channel (MSC), and the other is to find the optimal beamforming vector in terms of maximum sum rate. Our results show that the proposed NOMA scheme achieves higher sum rate than conventional orthogonal multiple access system. With optimal beamforming vector, the propose scheme can support higher rate even when the geometrical angle between two users is large.
48
Lai, Wei-Sheng, und 賴偉勝. „Joint Optimization of Resource Allocation and Admission Control in Heterogeneous OFDMA Networks“. Thesis, 2016. http://ndltd.ncl.edu.tw/handle/57758718598449151040.
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博士國立交通大學
電信工程研究所
104
Heterogeneous network is a promising technology for improving coverage and throughput of wireless communication systems. Since small cells are overlaid on and share the same spectrum with the existing cellular network, interference management is paramount for small cells. This dissertation studies the joint power and admission control (JPAC) problem for orthogonal frequency division multiplexing access (OFDMA) based heterogeneous networks. We consider a small-cell network coexisting with a macro-cell network. Small cells are not only subject to constraints imposed by interference with the macro-cell network but also by the minimum achievable rates of secondary user equipment (SUE). The goal is to admit as many SUE as possible to satisfy the minimum rate requirements while maximizing a certain network utility associated with the admitted SUE. To this end, we formulate two JPAC problems aimed at maximizing the network spectral efficiency (SE) and network energy efficiency (EE), respectively, where the latter has not been considered before. In light of the NP-hardness of the admission control and SE maximization problems, prior works have often treated the two problems separately without considering OFDMA constraints. In this dissertation, we propose a novel joint optimization framework that is capable of considering power control, admission control, and resource block assignment simultaneously. Via advanced convex approximation techniques and sequential SUE deflation procedures, we develop efficient algorithms that jointly maximize the SE/EE and the number of admitted SUE. Simulation results show that the proposed algorithms yield substantially higher SE/EE and admit more SUE than existing methods. The proposed optimization framework can provide a promising solution for heterogeneous OFDMA networks in future wireless communication systems.
49
Hsiao, Chun-Wei, und 蕭君維. „Joint Design of Statistical Precoder and Statistical Bit Allocation for Correlated MIMO Channels“. Thesis, 2011. http://ndltd.ncl.edu.tw/handle/69944201204975458409.
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碩士國立交通大學
電控工程研究所
100
In this thesis we consider the design of statistical precoder and statistical bit allocation for multi-input multi-output (MIMO) systems over correlated channels. We assume the correlated channel is slow fading and full channel state information is available at the receiver, while only the statistics of the correlated channels is assumed to be known at transmitter. We will first derive the statistical bound of bit error rate (BER) and the corresponding optimal real bit allocation. Based on this statistical BER bound, the optimal unitary statistical precoder is derived both for linear and decision feedback receiver. Second, the statistical integer bit allocation is designed the greedy algorithm. Finally, different number of substreams will be considered and selected by statistical BER bound. Simulations show lower BER can be achieved when optimal number of substreams is selected for correlated channels.
50
Soury, Hamza. „Joint Subcarrier Pairing and Resource Allocation for Cognitive Network and Adaptive Relaying Strategy“. Thesis, 2012. http://hdl.handle.net/10754/224711.
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Recent measurements show that the spectrum is under-utilized by licensed users in
wireless communication. Cognitive radio (CR) has been proposed as a suitable solution
to manage the inefficient usage of the spectrum and increase coverage area of
wireless networks. The concept is based on allowing a group of secondary users (SUs)
to share the unused radio spectrum originally owned by the primary user (PUs). The
operation of CR should not cause harmful interference to the PUs. In the other
hand, relayed transmission increases the coverage and achievable capacity of communication
systems and in particular in CR systems. In fact there are many types
of cooperative communications, however the two main ones are decode-and-forward
(DAF) and amplify-and-forward (AAF). Adaptive relaying scheme is a relaying technique
by which the benefits of the amplifying or decode and forward techniques can
be achieved by switching the forwarding technique according to the quality of the signal.
In this dissertation, we investigate the power allocation for an adaptive relaying
protocol (ARP) scheme in cognitive system by maximizing the end-to-end rate and
searching the best carriers pairing distribution. The optimization problem is under the interference and power budget constraints. The simulation results confirm the
efficiency of the proposed adaptive relaying protocol in comparison to other relaying
techniques, and the consequence of the choice of the pairing strategy.