Добірка наукової літератури з теми "338.18.78"

Biomorphic SiC ceramics were fabricated by infiltrating liquid silicon into woodceramics which were prepared from beech and pine impregnated with phenolic resin (PR) of different viscosity in order to reinforce the cell wall of wood. The viscosity of phenolic resin was adjusted by ethanol according to the weight ratio of PR to ethanol. The samples not impregnated with resin were compared. Effect of viscosity of phenolic resin on the dimension shrinkage, weight loss, porosity and the axial and radial flexural strength were investigated. Microstructural observation and phase identification of woodceramics and biomorphic SiC were performed by SEM and XRD, respectively. The results show that, the lower the viscosity of phenolic resin was, the higher the dimension shrinkage, weight loss and porosity of woodceramics were. Biomorphic SiC was a diphase composite consisting of major phase β-SiC and secondary phase Si. Woodceramics made from pine swelled or broke and strength of woodceramics fabricated from beech declined when higher viscosity resins were impregnated. The flexural strength of biomorphic SiC increased with increasing in viscosity of PR. The axial flexural strength was significantly higher than the radial flexural strength because of anisotropic pore microstructures.

Wireless multimedia sensor network routing protocols based on ant colony optimization algorithm (ACOQoS) is proposed. Based on the existing routing protocol design concept, and the actual needs of QoS from each network layer of wireless multimedia sensor networks, the protocols use the Agent collection method to select cluster head node, from the perspective of the balance network load. And maximize the network lifetime by balanced use of energy of the whole network.

WirelessHART, a kind of wireless mesh communication network that suits process automation, are widely used in the industrial fields. Routing algorithm performance directly determines sensor nodes how to transfer and control data, and the effective data rate. The algorithm which affects the energy consumption and lifetime of the whole sensor network is the core content of the network layer. WirelessHART network layer routing algorithm includes Source Route and Graph Route. In this paper, WirelessHART routing algorithm is simulated using nesC language in the TinyOS, and then compares with AODV protocol. And the data of experiment show the application advantage of WirelessHART Graph Route.

This paper presents an architecture for 32-bit datapath Advanced Encryption Standard(AES) IP core based on FPGA. It uses finite state machine, and supports encryption, decryption and key expansion. The round-key is calculated before the beginning of encryption and decryption. It consumes less hardware resources. It is implemented on Cyclone II FPGA EP2C35F672C6, which consumes less than 55% logic elements of the resources. The IP core can operate at a maximum clock frequency of 100 MHz. Compared with 128-bit datapath AES, it can interface with CPU easily.

Actual reflector antenna always has a deformation which has a serious influence on antenna performance. Establishing the equation of the distorted reflector surface is important for calculating antenna performance and precise control. A new best-fitting method based on least square method is submitted in this paper. This method depart from the ideal parabolic equation, and use the distance between the deformation point and the correspondent fitting point to establish the least square error condition equations, though which the six parameters can be got to determine the geometry position of the deformed parabolic accurately. Matrix operation can make the algorithm easy to realize in computer. Nan-shan 25m antennas finite element model is established in ANSYS program, and its result is analyzed compared with another method, confirmed the operability and accuracy of this algorithm.

In this paper, an improved kernel independent component analysis (KICA) algorithm is proposed for multi-user detection (MUD). In this algorithm, a new hybrid kernel function is adopted. In addition, the bat algorithm is applied to the optimizing process of independent component separation. Simulation results show that the new hybrid kernel function performs better in MUD than other kernel functions, and the improved KICA with bat algorithm has the smallest bit error rate (BER) when compared with classical FastICA and KICA algorithms.

For the linearization of power amplifiers, a digital pre-distorter is proposed to compensate nonlinear distortion in this paper. The pre-distorter is realized by Volterra series, and a restarted limited memory BFGS(LBFGS) algorithm is proposed for training the nonlinear pre-distorter. Training of Volterra series can be switched between gradient descend algorithm and quasi Newton algorithm by setting a switching condition, and LBFGS algorithm can be used for high dimensional iterative matrix of BFGS algorithm. These make the new algorithm much more stable with a fast convergence rate. The pre-distorter is used for OFDM power amplifiers and it high efficiency is proved by simulation results. Moreover, the convergence rate of the proposed algorithm is greatly faster than that of the gradient algorithm.

According to characteristics that the vehicles move fast and topology changes quickly in Vehicular Ad hoc Networks (VANETs), a novel routing protocol GMGP based on the location is proposed for VANETs. Predicting the changes of the neighboring nodes positions and using greedy forwarding mechanism forward packet, and using a movement perimeter forwarding algorithm to select the next reliable hop node on the basis of direction and velocity of the mobile nodes when the greedy forwarding fails, it improves the reliability of routing. When a more realistic vehicles mobility model is applied to the NS-2 simulation platform, the simulation indicates that the improved routing protocol has better performance than the GPSR routing protocol.

When there are multiple electronic tags in the reading range of reader, It arises problem of multiple tags data collision in the data communication process of RFID system, causing the data reader have obtained error. This paper will contrapose the problem of tag collision, analysizing the search number and the system throughput rate of the existing anti-collision search algorithm based on binary, to propose an improved anti-collision algorithm. The improved algorithm reduces the redundant information of the sequence number that the reader have sent, and no longer searchs the tags of one bit collided ,but identify the two collided tags directly, thus reducing the search number of algorithm. Matlab simulation show that this algorithm can reduce the search number of reader identifying tags, improving the identifying efficiency of the RFID system, solving the problem of tag collision effectively.

This paper proposes a complete set of Urban Parking Guidance and Information System, which includes Parking Subsystem and City Parking Subsystem. The system adopts wireless sense network based on ZigBee technology for the communication network. The parking information terminals that set up in the parking areas automatically identify the parking vehicles and upload the parking information. After processing the data, the Central Control Module would distribute the parking information by LCD screens for the drivers. In terms of parking supply and demand status, the system sends the separately parking information to the corresponding phone number. The system achieves barrier-free intelligent parking management by realizing functions such as three ways of releasing the information of parking lots, inquiry of parking location and convenient register operation.

Магістерська дисертація на тему: «Підвищення ефективності зовнішньоекономічної діяльності підприємства» містить 102 сторінок, 31 таблиць, 19 рисунків, 17 формул. Перелік посилань нараховує 65 найменувань. Актуальність теми полягає в підвищенні ефективності зовнішньоекономічної діяльності підприємництва як головної форми господарювання в сучасних умовах трансформації економіки пов’язане з активізацією та удосконаленням організаційного, фінансового менеджменту, господарського механізму загалом. Теоретичні і методологічні аспекти визначення ефективності діяльності підприємств знайшли відображення в працях таких вітчизняних вченихекономістів, як Т.В. Якимчук, Л.В. Фролова, А.М. Турило, Є.М. Сич, І.А. Маркіна, Т.С. Голубєва, В.В. Прядко, О.О. Канцуров, О.І. Макаренко, Т.Ф. Касянчук. Основною метою дослідження є систематизація теоретико-методичних засад та розроблення практичних рекомендацій щодо підвищення ефективності діяльності підприємства ТОВ «Фарадей Електронікс». Задачі даної роботи: дослідити та проаналізувати зовнішнє середовище підприємства та фінансовоекономічний стан ТОВ «Фарадей Електронікс і розробити рекомендації . Об’єктом дослідження є розвиток зовнішньоекономічної діяльності підприємства. Предметом дослідження є напрями підвищення ефективності зовнішньоекономічної діяльності підприємства ТОВ «Фарадей Електронікс». Практична значущість магістерської дисертації полягає у виявленні можливостей для підвищення ефективності зовнішньоекономічної діяльності ТОВ «Фарадей Електронікс». Апробація результатів дослідження: Николаїшин Н.П. Оцінка ефективності зовнішньоекономічної діяльності підприємства. «Розвиток підприємництва як фактор росту національної економіки» ХІХ Міжнародної науково-практичної конференції. 25.11.2020. м. Київ. Николаїшин Н.П. Кузнєцова К.О. Шляхи підвищення ефективності зовнішньоекономічної діяльності транспортного підприємства, «Сучасні проблеми і перспективи розвитку обліку, аналізу і контроль в умовах глобалізації економіки» ХІІ Міжнародної науково-практичній конференції. 05.12.2020. м. Луцьк. У висновках та пропозиціях узагальнено результати дослідження.
Master's dissertation on the topic: "Improving the efficiency of foreign economic activity of the enterprise" contains 102 pages, 31 tables, 19 figures, 17 formulas. The list of links includes 65 items. The urgency of the topic is to increase the efficiency of foreign economic activity of entrepreneurship as the main form of management in modern economic transformation is associated with the activation and improvement of organizational, financial management, economic mechanism in general. Theoretical and methodological aspects of determining the efficiency of enterprises are reflected in the works of such domestic economists as T.V. Yakimchuk, LV Фролова, А.М. Turilo, E.M. Сич, І.А. Markina, T.S. Golubeva, VV Прядко, О.О. Kantsurov, OI Makarenko, TF Kasyanchuk. The main purpose of the study is to systematize the theoretical and methodological principles and develop practical recommendations for improving the efficiency of the company LLC "Faraday Electronics". Objectives of this work: to investigate and analyze the external environment of the enterprise and the financial and economic condition of Faraday Electronics LLC and develop recommendations. The object of research is the development of foreign economic activity of the enterprise. The subject of the research is the directions of increasing the efficiency of foreign economic activity of the enterprise LLC "Faraday Electronics". The practical significance of the master's dissertation is to identify opportunities to increase the efficiency of foreign economic activity of Faraday Electronics LLC. Approbation of research results: Nykolaishyn N.P. Evaluation of the effectiveness of foreign economic activity of the enterprise. "Development of Entrepreneurship as a Factor of National Economy Growth" of the XIX International Scientific and Practical Conference. 11/25/2020 m. Kyiv. Nуkolaishyn N.P. Kuznetsova K.O. Ways to increase the efficiency of foreign economic activity of the transport enterprise, "Modern problems and prospects for the development of accounting, analysis and control in the context of economic globalization" XII International Scientific and Practical Conference. 12/05/2020 Lutsk city. The conclusions and proposals summarize the results of the study.

This thesis investigates the membership, activities and policy impact of three distinct groups of policy networks operating within and between the agricultural policy environments of the US and EC as well as at the multilateral level during the preparation for and negotiations of the GATT Uruguay Round between 1980 and 1993. Briefly defined, these three groups are: 1) epistemic communities - networks of professionals who share both specialized knowledge and expertise in a specific issue area; 2) advocacy coalitions - policy actors from various levels of the policy process who share common policy beliefs and work together to turn these policy beliefs into government policy; and 3) elite transnational networks - incorporating political leaders, political appointees and senior government and international institutional officials, these elite level networks are formed through regular contact in either an official or unofficial capacity. The contention of this thesis is that various networks of actors within the distinct policy networks of epistemic communities, advocacy coalitions and elite transnational networks contributed significantly to bringing about the reform of agricultural policy that occurred within the EC and the US between 1980 and 1993 allowing for the establishment of consensus on the liberalization of agricultural trade policy at the multilateral level of the General Agreement on Tariffs and Trade during the Uruguay Round. The hypothesis of this thesis is that these three policy networks varied in their impact according to the specific stage of negotiations due to changing policy needs. I argue that in general: 1) epistemic communities exhibited the most impact during the agenda-setting stage owing in part to their expertise in agricultural trade issues, the existence of a common framework for discussion and their work in creating analytical tools that allowed agricultural liberalization to be politically and economically viable; 2) advocacy coalitions had the most significant role during the second, or policy-making stage, due to their ability to work within the policy environment and shape domestic policy development; and 3) elite transnational networks, due to their ability to provide the necessary political pressure, had the greatest impact in the third, or breakthrough stage.

Livestock-based agriculture plays an important role in the development of sub-saharan Africa, especially those countries whose livestock industry contributes significantly to the Gross Domestic Product (GDP). In Kenya, agriculture alone accounts for 21% of the GDP and provides employment directly or indirectly to over 75% of the total labour force. The livestock industry, mainly arid rangelands, contributes 50% of the agricultural productivity. However, these Arid and Semi-Arid Lands (ASALs) are exposed to a myriad of risks affecting the environment which is the pastoral core asset. These risks arise from climatic change and variability, growth in human population and expanding settlements, changes in the land use systems, poor infrastructure, diseases, wildlife predation, and inter-ethnic conflicts. The consequences of these pastoral risks include: (1) declining per capita asset value, (2) increased health problems, (3) increased poverty, and (4) declining GDP generated from pastoralism. While a lot of resources have been invested in responding to the pastoral crisis associated with droughts, there is still inadequate understanding of the policy measures to put in place as mitigation strategies. The aims of this research are (1) identify the main pastoral risks and community response strategies, (2) assess the impact the identified risks on the wellbeing of pastoralists based on financial, human, physical, natural and social capital measurements (5 C‘s), and (3) develop a System Dynamics (SD) model to assess the holistic impact of community and government response strategies on pastoral wellbeing. Samburu district, in northern Kenya, was chosen as a study area because it is classified as 100% ASAL and experiences frequent droughts and changing land use systems. The research process involved literature synthesis, analysis of both cross-sectional and a 5-year panel data, and the development of a System Dynamics model. Cross-section data was primarily collected for the purposes of identifying the extent to which risks affect households, while the 5-year panel data was sourced from the Arid Lands Resource Management Project (ALRMP). Descriptive and empirical analysis showed that droughts, land use system and human population were considered as the main cause of shrinking rangeland productivity and as a result declining per capita livestock. This was further confirmed from the panel data analysis indicating climate variability as the main driver of pastoral wellbeing. Droughts affect rangeland pasture productivity, market prices, livestock assets, and households‘ nutritional status and poverty levels. These results imply a multifaceted nature of pastoral system with compound affects. The SD simulation result, which was run over the period January 2006 to December 2030, provided insights on policy evaluation and the state of pastoral wellbeing. Baseline scenario indicated reducing livestock ownership, causing high malnutrition and poverty rates. Strategies which incorporated rangeland rehabilitation, planned settlements, livestock disease control, insurance against droughts, reducing inter-ethnic conflicts, and timely destocking offered better policy options. These strategies resulted in reduced malnutrition, increased pasture productivity, reduced livestock losses and ultimately reducing poverty rates among the pastoral communities.