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Fong, K., i J. Reinstedler. "Development of an OSI application layer protocol interface". ACM SIGCOMM Computer Communication Review 19, nr 3 (lipiec 1989): 21–57. http://dx.doi.org/10.1145/74674.74676.
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Shiroshita, T. "A data processing performance model for the OSI application layer protocols". ACM SIGCOMM Computer Communication Review 20, nr 4 (sierpień 1990): 60–68. http://dx.doi.org/10.1145/99517.99535.
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Karbowski, Andrzej. "Distributed asynchronous algorithms in the Internet – new routing and traffic control methods". Journal of Telecommunications and Information Technology, nr 3 (30.09.2005): 29–36. http://dx.doi.org/10.26636/jtit.2005.3.328.
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The paper presents several new algorithms concerning the third (network) and the fourth (transport) layer of ISO/OSI network model. For the third layer two classes of the shortest paths algorithms – label correcting and auction algorithms – are proposed. For the fourth layer an application of price decomposition to network optimization and Internet congestion control is suggested.
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Ivanov, Valeriy, i Maxim Tereshonok. "Cross-Layer Methods for Ad Hoc Networks—Review and Classification". Future Internet 16, nr 1 (16.01.2024): 29. http://dx.doi.org/10.3390/fi16010029.
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The OSI model used to be a common network model for years. In the case of ad hoc networks with dynamic topology and difficult radio communications conditions, gradual departure is happening from the classical kind of OSI network model with a clear delineation of layers (physical, channel, network, transport, application) to the cross-layer approach. The layers of the network model in ad hoc networks strongly influence each other. Thus, the cross-layer approach can improve the performance of an ad hoc network by jointly developing protocols using interaction and collaborative optimization of multiple layers. The existing cross-layer methods classification is too complicated because it is based on the whole manifold of network model layer combinations, regardless of their importance. In this work, we review ad hoc network cross-layer methods, propose a new useful classification of cross-layer methods, and show future research directions in the development of ad hoc network cross-layer methods. The proposed classification can help to simplify the goal-oriented cross-layer protocol development.
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O. Hasan, Ammar. "Application Based performance monitoring heavy data transmission of Local Area Network". Kufa Journal of Engineering 13, nr 3 (31.07.2022): 14–40. http://dx.doi.org/10.30572/2018/kje/130302.
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There are many applications should be work online, these applications can be seen in the application layer of OSI reference model, each one of these consumes particular band width, bit rate and network speed depending of the resources that used to make any application operate for example there is a widely difference between video streaming network application and text chatting application. In this paper when any computer network needs to be examined, at least two different applications should be taken for example to monitor network performance when these application going to work and get in action. In this paper the researcher designed and a local area network to implement dedicated applications, monitor the network factors performance, get results, and compare between applications.
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T, Varsha, Shrihari i Dr Nagaraja G. S. "IoT based a Smart Home Automation System Using Packet Tracer". International Journal for Research in Applied Science and Engineering Technology 11, nr 1 (31.01.2023): 183–87. http://dx.doi.org/10.22214/ijraset.2023.48514.
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Abstract: The technology is seeing a rapid growth day by day in the life of humans. Rapid growth intechnology has led to newer inventions that has made human lives very comfortable. The introduction of Internet Of Things (IOT) has brought a drastic change in the way humans lead their lives. Network plays an important role in each and every technology as it allows connection and communication between different objects and entities of any application. Different models like OSI, TCP demonstrate how computer system communicate over a network. Each of these models have different layers in it. This paper mainly focuses on the application layer which enables effective communication with other applications on different computer systems and different networks. Also the paper discuss different application layer IoT based protocols that work in the application layer by considering the scenario of Smart Home to demonstrate working of each protocol.
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Susilawati Susilawati, Marcel Ade Satria, Khaila Mardina, Juniwan Juniwan i Didik Aribowo. "Implementasi Teknologi Komunikasi Data Menggunakan Open System Interconnection (OSI) Untuk Berkirim Pesan Antar Perangkat". Venus: Jurnal Publikasi Rumpun Ilmu Teknik 2, nr 3 (17.05.2024): 124–29. http://dx.doi.org/10.61132/venus.v2i3.307.
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Currently, the development of communication networks has influenced how humans communicate and exchange information. Data communications technology reflects the rapid evolution in the way humans communicate and exchange information. Data communication is the process of exchanging information between two or more devices via a transmission medium, such as cables, radio waves, or other network infrastructure. The goal of data communications is to transfer data from one location to another quickly, efficiently, and accurately. The method used is to look for references from several internet sources such as Google. The OSI model has 7 layers, namely Application Layer, Presentation layer, Session Layer, Transport layer, Network layer, data link layer, physical layer
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Abilov, A. V., A. V. Chunaev, A. I. Nistyuk i I. A. Kaisina. "Data Transmission Model with Lost Fragments Recovery Based on Application Layer ARQ". Bulletin of Kalashnikov ISTU 23, nr 4 (30.12.2020): 85. http://dx.doi.org/10.22213/2413-1172-2020-4-85-94.
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Для сетей беспроводной связи в сложных условиях приема характерен высокий уровень группирования потерь, при котором может теряться подряд большое количество фрагментов данных. В этом случае для восстановления потерянных данных применение методов прямой коррекции потерь FEC в большинстве случаев не дает достаточного эффекта.Применение стандартных методов восстановления потерь данных на основе автоматического запроса повторной передачи ARQ на канальном и транспортном уровнях модели OSI может привести к появлению существенных задержек, что является неприемлемым для сервисов потоковой передачи в реальном режиме времени. В этом случае предпочтительнее пропустить фрагмент данных, чем вносить задержку на ожидание доставки фрагмента при повторных передачах. Применение методов, основанных на ARQ прикладного уровня модели OSI для потоковой передачи данных, позволяет более эффективно восстанавливать потерянные фрагменты данных в сетях беспроводной связи с высоким уровнем группирования потерь. Известные модели дискретного канала передачи информации для беспроводных сетей позволяют аналитически оценить вероятность потерь данных, однако не учитывают случаи с повторной передачей потерянных данных.В исследовании предложена математическая модель передачи данных в канале беспроводной связи на основе модели Гильберта, которая учитывает восстановление потерь методом ARQ и позволяет рассчитывать коэффициент потерь фрагментов данных. Для проверки адекватности предложенной модели разработано программное обеспечение, обеспечивающее передачу потоковых данных в сети беспроводной связи с восстановлением потерь фрагментов на прикладном уровне, и проведено соответствующее экспериментальное исследование. Показано, что математическая модель учитывает группирование потерь передаваемых данных и их восстановление методом ARQ.
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Nakao, K., i K. Suzuki. "Proposal on a secure communications service element (SCSE) in the OSI application layer". IEEE Journal on Selected Areas in Communications 7, nr 4 (maj 1989): 505–16. http://dx.doi.org/10.1109/49.17714.
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Jiang, Jian Feng, Jian Feng Jiang, Xian Zhang i Jin Xia Sun. "Complementary QoS Strategy Research and Application in Large-Scale Switched Networks". Advanced Materials Research 712-715 (czerwiec 2013): 2664–70. http://dx.doi.org/10.4028/www.scientific.net/amr.712-715.2664.
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Large-scale switched networks based on hierarchical architecture put forward higher requirements for the quality of service. This paper analyzes the advantages, disadvantages and the application environment of the traditional QoS architecture based on business according to the second layer and the third layer of the OSI reference model. Then a complementary strategy model integrating Differentiated service model with Integrated service model is designed to enhance the QoS of a large-scale switched network. Simulation results prove that the model can improve the networks QoS in many aspects such as transmission delay, packet loss rate, delay jitter and network throughput.
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Abilov, A. V., A. V. Chunaev, A. I. Nistyuk i I. A. Kaisina. "Data Transmission Model with Lost Fragments Recovery Based on Application Layer ARQ". Vestnik IzhGTU imeni M.T. Kalashnikova 24, nr 3 (2021): 104–11. http://dx.doi.org/10.22213/2413-1172-2021-3-104-111.
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Wireless networks in difficult conditions of signal receiving are characterized by a high level of burst data losses, at which a large number of data fragments can be lost in a row. In this case, to recover the lost data, the use of forward error correction methods (FEC) in most cases does not give a sufficient effect. The use of standard data loss recovery methods based on automatic retransmission request (ARQ) at the data link and transport layers of the OSI model can lead to significant delays, which is often unacceptable for real-time streaming services. In such a case, it may be preferable to skip the piece of data rather than delay waiting for the piece to be delivered on retransmissions. The use of ARQ-based techniques on application layer of OSI model for data streaming allows for a more efficient recovery of lost data chunks in wireless networks with a high level of burst losses. The known models of a discrete channel for wireless networks allow for analytically assessing the probability of data loss, however, they do not take into account cases with retransmission of lost data. The study proposes a mathematical model of data transmission in a wireless communication channel based on the Gilbert model, which takes into account the loss recovery by the ARQ method and allows you to calculate the data loss ratio. To check the adequacy of the proposed model, a software was developed that ensures the transmission of data streaming in a wireless communication network with recovery of fragment losses at the application level, and a corresponding experimental study was carried out. It is shown that the mathematical model takes into account the burstiness of transmitted data losses and their recovery by the ARQ method.
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R, Gautam, Suyog P i G. S. Nagaraja. "Analysis of SNMP Based Protocols in IoT and Real- World Scenarios". International Journal for Research in Applied Science and Engineering Technology 10, nr 11 (30.11.2022): 1867–71. http://dx.doi.org/10.22214/ijraset.2022.47293.
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bstract: In the scenario of large organizations device management and maintenance plays an important role in proper functioning of network connected devices. SNMP (Simple NetworkManagement Protocol) is an internet Protocol running in the application layer of the OSI modelthat governs the functioning of the network devices such as routers, switches and access points. The implementation of SNMP is done mainly using UDP (User Datagram Protocol) which is best effort protocol leaving the responsibility of error correction to the application layer. Whatcan be gathered from the local device and what may be modified and set are specified by SNMPManagement Information Bases, or MIBs for short.
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Orphanos, George N., George D. Papadopoulos i Stavros A. Koubias. "MACSE: A generic connection establishment protocol for multimedia communication residing at the OSI application layer". European Transactions on Telecommunications 9, nr 3 (maj 1998): 295–311. http://dx.doi.org/10.1002/ett.4460090309.
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Tennakoon, Chaminda, i Subha Fernando. "Deep learning model for distributed denial of service (DDoS) detection". International Journal of ADVANCED AND APPLIED SCIENCES 9, nr 2 (luty 2022): 109–18. http://dx.doi.org/10.21833/ijaas.2022.02.012.
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Distributed denial of service (DDoS) attacks is one of the serious threats in the domain of cybersecurity where it affects the availability of online services by disrupting access to its legitimate users. The consequences of such attacks could be millions of dollars in worth since all of the online services are relying on high availability. The magnitude of DDoS attacks is ever increasing as attackers are smart enough to innovate their attacking strategies to expose vulnerabilities in the intrusion detection models or mitigation mechanisms. The history of DDoS attacks reflects that network and transport layers of the OSI model were the initial target of the attackers, but the recent history from the cybersecurity domain proves that the attacking momentum has shifted toward the application layer of the OSI model which presents a high degree of difficulty distinguishing the attack and benign traffics that make the combat against application-layer DDoS attack a sophisticated task. Striding for high accuracy with high DDoS classification recall is key for any DDoS detection mechanism to keep the reliability and trustworthiness of such a system. In this paper, a deep learning approach for application-layer DDoS detection is proposed by using an autoencoder to perform the feature selection and Deep neural networks to perform the attack classification. A popular benchmark dataset CIC DoS 2017 is selected by extracting the most appealing features from the packet flows. The proposed model has achieved an accuracy of 99.83% with a detection rate of 99.84% while maintaining the false-negative rate of 0.17%, which has the heights accuracy rate among the literature reviewed so far.
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Martynenkov, I. V. "THE MAIN STAGES OF DEVELOPMENT OF THE CRYPTOGRAPHIC PROTOCOLS SSL/TLS AND IPsec". Prikladnaya Diskretnaya Matematika, nr 51 (2021): 31–67. http://dx.doi.org/10.17223/20710410/51/2.
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The paper discusses the main stages of development of cryptographic protocols from SSL 2.0 (Secure Socket Layer) to TLS 1.3 (Transport Layer Security), which ensure the protection of transport layer data in the OSI model. A brief description of the modification of the RuTLS protocol based on TLS 1.3 and their main differences is given. The development of IPsec, which provides cryptographic protection of communications at the network level of the OSI model, is considered using examples of the development of the three most commonly used protocols. These include IKE (Internet Key Exchange), AH (Authentication Header), and ESP (Encapsulation Security Payload). For the SSL/TLS and IPsec specifications, the basic handshake protocols and the main stages of their development are considered. The described handshakes include primary cryptographic information exchange cycles in the form of identifiers of interaction participants, one-time numbers, lists of supported cryptographic combinations. Authentication of participants based on certificates, shared symmetric keys, data exchange for establishing a shared Diffie — Hellman secret, development of key material for secret keys of communication sessions, message authentication, and other cryptographic parameters are presented. For different versions of SSL/TLS and IPsec, the logical structures of application data cryptographic protection functions are described.
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Jafri, Syed Talib Abbas, Irfan Ahmed, Sundus Ali, Jamaiah Yahaya, Faizan Qamar i Zuriani Hayati Abdullah. "Split Hop Penalty for Transmission Quality Metrics in a Better Approach to Mobile Ad Hoc Networking (BATMAN) for IoT-Based MANET". Symmetry 15, nr 5 (24.04.2023): 969. http://dx.doi.org/10.3390/sym15050969.
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Various routing protocols have been developed for wireless ad hoc networks to shift from infrastructure-based networks to self-controlling and self-configurable networks. These ad hoc networks are easy to implement and have plenty of application in the fields of healthcare, transportation, smart cities, etc. Although almost all of the routing protocols work on the Open Systems Interconnection (OSI) model’s network layer, a few routing protocols support routing on the data link layer of the OSI model rather than the conventional one. One of these routing protocols include the Better Approach To Mobile Ad Hoc Networking (BATMAN). Though BATMAN is a comparably new routing protocol and included in the Linux kernel, it suffers from performance deterioration and latency issues that need to be addressed especially in the Internet of Things (IoT). This paper presents a symmetry-based split hop penalty for BATMAN version 4 to improve the network’s performance in multi-hop scenarios. Split hop penalty defines two different sets of penalties to accommodate the routing protocol metric based on the interface media type. The experiments were conducted within the campus building of the university with physical nodes, and the obtained results highlight that overall performance is improved in terms of throughput, latency, and jitter while no performance gain is measured in packet loss and routing loops that are still present.
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Chacón, Edgar, i Orestes Llanes Santiago. "Definition of a control service in the application layer of the ISO/OSI reference model for control stations". Computers in Industry 20, nr 2 (styczeń 1992): 187–92. http://dx.doi.org/10.1016/0166-3615(92)90052-o.
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Al Hayajneh, Abdullah, Md Zakirul Alam Bhuiyan i Ian McAndrew. "A Novel Security Protocol for Wireless Sensor Networks with Cooperative Communication". Computers 9, nr 1 (20.01.2020): 4. http://dx.doi.org/10.3390/computers9010004.
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This paper builds upon the foundation and clarifies specifications for a necessary security protocol in Wireless Sensor Networks (WSNs) with cooperative communications. It is designed to enhance performance and resiliency against cyber-attacks. Recent literature has shown that developing a WSN with Cooperative Communication greatly increases the performance of the network, but also exposes new vulnerabilities. The technique operates by transmitting packets of data to neighboring relay nodes in a cooperative fashion to reach the destination. In this paper, we consider security issues in WSNs with cooperative communication on each layer of the OSI model: physical layer, data link layer, network layer, service (topology) layer, and application layer. For each layer, we clarify the main task, enumerate the main attacks and threats, specify the primary security approaches and techniques (if any), and discuss possible new attacks and problems that may arise with the use of cooperative communications. Furthermore, we show for some attacks (e.g., jamming, packet dropping, and wormhole) that using cooperative communication improves the network resiliency and reliability. Finally, we propose a security protocol that addresses many of these shortcomings, while outlining the remaining issues that need further work and research.
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Sabelkin, Mike, i François Gagnon. "Data Transmission Oriented on the Object, Communication Media, Application, and State of Communication Systems". International Journal of Interdisciplinary Telecommunications and Networking 3, nr 2 (kwiecień 2011): 51–65. http://dx.doi.org/10.4018/jitn.2011040104.
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The proposed communication system architecture is called TOMAS, which stands for data Transmission oriented on the Object, communication Media, Application, and state of communication Systems. TOMAS could be considered a Cross-Layer Interface (CLI) proposal, since it refers to multiple layers of the Open Systems Interconnection Basic Reference Model (OSI). Given particular scenarios of image transmission over a wireless LOS channel, the wireless TOMAS system demonstrates superior performance compared to a JPEG2000+OFDM system in restored image quality parameters over a wide range of wireless channel parameters. A wireless TOMAS system provides progressive lossless image transmission under influence of moderate fading without any kind of channel coding and estimation. The TOMAS system employs a patent pending fast analysis/synthesis algorithm, which does not use any multiplications, and it uses three times less real additions than the one of JPEG2000+OFDM.
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Ikuesan, Adeyemi R., Mazleena Salleh, Hein S. Venter, Shukor Abd Razak i Steven M. Furnell. "A heuristics for HTTP traffic identification in measuring user dissimilarity". Human-Intelligent Systems Integration 2, nr 1-4 (2.06.2020): 17–28. http://dx.doi.org/10.1007/s42454-020-00010-2.
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AbstractThe prevalence of HTTP web traffic on the Internet has long transcended the layer 7 classification, to layers such as layer 5 of the OSI model stack. This coupled with the integration-diversity of other layers and application layer protocols has made identification of user-initiated HTTP web traffic complex, thus increasing user anonymity on the Internet. This study reveals that, with the current complex nature of Internet and HTTP traffic, browser complexity, dynamic web programming structure, the surge in network delay, and unstable user behavior in network interaction, user-initiated requests can be accurately determined. The study utilizes HTTP request method of GET filtering, to develop a heuristic algorithm to identify user-initiated requests. The algorithm was experimentally tested on a group of users, to ascertain the certainty of identifying user-initiated requests. The result demonstrates that user-initiated HTTP requests can be reliably identified with a recall rate at 0.94 and F-measure at 0.969. Additionally, this study extends the paradigm of user identification based on the intrinsic characteristics of users, exhibited in network traffic. The application of these research findings finds relevance in user identification for insider investigation, e-commerce, and e-learning system as well as in network planning and management. Further, the findings from the study are relevant in web usage mining, where user-initiated action comprises the fundamental unit of measurement.
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Chupaev, A. V., R. S. Zaripova, R. R. Galyamov i A. Y. Sharifullina. "The use of industrial wireless networks based on standard ISA-100.11a and protocol WirelessHART in process control". E3S Web of Conferences 124 (2019): 03013. http://dx.doi.org/10.1051/e3sconf/201912403013.
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This article considers wireless technologies in the field of automation of technological processes and production in the energy, chemical, petrochemical and oil refining, gas, railway, mining, metallurgical and other industries where the use of wireless industrial devices is necessary due to specific features. Wireless technologies provide the ability to connect measuring devices directly to the wireless network with further transfer of information through a wireless gateway to an automated control system. This article will discuss the types of wireless networks that are classified according to the possible range of action (Wireless Wide area network, Wireless Local Area Network, Wireless Personal Area Network). The most common standards of organization of wireless industrial networks, including IEEE 802.11 b/g/n, IEEE 802.15.1, IEEE 802.15.4, IEEE 802.16 e, will also be considered, including in the field of management of chemical-technological processes and productions. Data transmission protocols ISA-100.11.a and WirelessHART and a number of their features will be analyzed. The basic standard network structures based on the ISA-100.11.a and WirelessHART protocols, their typical components, will be considered. The article provides an analytical comparison of the ISA100.11a and WirelessHART over the OSI network model layers, including the physical layer, the link layer, the network layer, the transport layer, the session layer, the presentation layer and the application layer (process control, management, security, application sublayer). The main stages of calculation of wireless industrial network are given, in particular: calculation of the network information load, calculation of the network’s energy parameters, frequency-territorial planning, development of the communication scheme and interface with external networks. The formulas for calculating the network information load using Nazarov’s methodology, calculating the network’s energy parameters, taking into account the overall losses in the propagation of radio waves, including losses in free space, losses in partitions and walls inside the building, losses due to interference and signal fading are given.
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Gadasin, Denis V., i Andrey V. Schvedov. "APPLICATION OF A TRANSPORT TASK FOR LOAD BALANCING IN CONDITIONS OF SOURCE DATA FUZZINESS". T-Comm 18, nr 1 (17.01.2024): 13–20. http://dx.doi.org/10.36724/2072-8735-2024-18-1-13-20.
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The structure of the ISO/OSI model does not allow choosing the optimal packet transmission route at the channel level and preventing the formation of ring routes. These functions are performed by the network layer. In general, the problem of packet routing is solved by the switch based on the routing algorithm, which contains a hidden "flooding" mechanism. A packet from the sender's switch is sent to all ports, except for the port where the packet was received. When a packet arrives, the switch analyzes the header and if the address in the header matches the address to which the switch belongs, then the packet is accepted. This situation, combined with the unevenness of sending a message, creates an increased load on switching devices at random times and determines the problem of distributing the input data flow in conditions of pulsating traffic. Pulsating traffic can be considered as a fuzziness lying within certain boundaries. To smooth traffic, it is possible to use clusters of switching devices, which in turn are considered as outgoing devices for the next level of clusters. Thus, to distribute the load, it is possible to apply the flow distribution algorithm used in solving the transport problem.
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Sambangi, Swathi, i Lakshmeeswari Gondi. "A Machine Learning Approach for DDoS (Distributed Denial of Service) Attack Detection Using Multiple Linear Regression". Proceedings 63, nr 1 (25.12.2020): 51. http://dx.doi.org/10.3390/proceedings2020063051.
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The problem of identifying Distributed Denial of Service (DDos) attacks is fundamentally a classification problem in machine learning. In relevance to Cloud Computing, the task of identification of DDoS attacks is a significantly challenging problem because of computational complexity that has to be addressed. Fundamentally, a Denial of Service (DoS) attack is an intentional attack attempted by attackers from single source which has an implicit intention of making an application unavailable to the target stakeholder. For this to be achieved, attackers usually stagger the network bandwidth, halting system resources, thus causing denial of access for legitimate users. Contrary to DoS attacks, in DDoS attacks, the attacker makes use of multiple sources to initiate an attack. DDoS attacks are most common at network, transportation, presentation and application layers of a seven-layer OSI model. In this paper, the research objective is to study the problem of DDoS attack detection in a Cloud environment by considering the most popular CICIDS 2017 benchmark dataset and applying multiple regression analysis for building a machine learning model to predict DDoS and Bot attacks through considering a Friday afternoon traffic logfile.
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Kaisina, I. A., A. V. Abilov, M. A. Lamri, K. E. Korepanov i R. E. Shibanov. "Methods for Priority Relaying of Multi-Stream Data at the Application Layer in the UAV Networks". Vestnik IzhGTU imeni M.T. Kalashnikova 25, nr 1 (2022): 91–99. http://dx.doi.org/10.22213/2413-1172-2022-1-91-99.
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The article presents methods for relaying Multi-Stream data at the application layer of OSI model through a relay node in UAV networks - MS-AL-ARQ Relaying methods. MS-AL-ARQ method is taken as the principal one. One of the basic operating principles of Application Layer ARQ-based Multi-Streaming (MS-AL-ARQ) is to determine a lost fragment from one of the source nodes based on a sequence number with an IP address ID. After determination of the lost data fragment, a negative non-acknowledgment NACK is sent to the source node. A round trip time RTT is set, after each NACK to schedule the requesting process. This action is performed until data fragment is received or the data fragment timeout RTO expires. The main difference between MS-AL-ARQ and MS-AL-ARQ Relaying is that MS-AL-ARQ Relaying works with buffers on the source and destination nodes as well as working with a buffer on the relay node. To describe the methods, the definition of a leading/priority source node with sending video priority, was introduced. The core metrics for determination of the leading node is the packet delivery ratio (counter PDR), which calculates the value at the relay node in a given interval and only then transmits data to the recipient node. There are several options to define the leading/priority source node: default, static, and dynamic definition. In this case, the situation with the flying relay node and the ground relay node is considered separately. The choice of relay node position is related to the characteristics of the node. Thus, a ground-based relay node could be a laptop, where the computing resources are often higher and the memory capacity can allow storing incoming data for longer time periods and a flying relay node is represented by a UAV with limited productive resources. The final part presents a test bench for further laboratory testing of the MS-AL-ARQ Relaying method and the results of laboratory tests confirming the relevance of developing algorithms based on MS-AL-ARQ Relaying methods.
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Shibanov, R. E., I. A. Kaysina, A. V. Abilov i K. E. Korepanov. "Transmission quality evaluation of multistreaming video data from the UAV to the ground station in network simulator 3 simulation environment using WI-FI standards". Vestnik IzhGTU imeni M.T. Kalashnikova 26, nr 1 (8.04.2023): 91–99. http://dx.doi.org/10.22213/2413-1172-2023-1-91-99.
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The article presents the results of transmitting video data simulation in real time from video cameras on board Unmanned Aerial Vehicles (UAVs) to a ground station (GS). The main purpose of the article was to evaluate the impact of the flying source node number on Quality of Service (QoS) metrics, such as Packet Delivery Ratio and Goodput at OSI model application layer. A scenario was considered when hovering over UAVs, in the zone of reliable communication, transmitted a stream of video data to a ground station, then the distance between the UAV and the GS increased to repeat the experiment. The bitrate was maintained at the same level, close to the bitrate of real high-definition video. The experiment was carried out in the Network Simulator 3 (NS-3) simulation environment for scenarios with one, two, four, and eight source nodes. Simulation results have shown the negative impact of the increasing the number of flying source nodes on Quality of Service (QoS) metrics such as Packet Delivery Rate (PDR) and Goodput. Recommendations regarding the applicability of different standards of the 802.11 family to scenarios for using UAVs in the multistreaming video data transmission mode are given. A change in the relationship of useful throughput on the number of source nodes by 15 % was also found.
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Engelhardt, Michael, Arne Hildebrand, Dagmar Lange i Thomas C. Schmidt. "Semantic overlays in educational content networks – the hylOs approach". Campus-Wide Information Systems 23, nr 4 (1.08.2006): 254–67. http://dx.doi.org/10.1108/10650740610704126.
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PurposeThe paper, aims to introduce an educational content management system Hypermedia Learning Objects System (hylOs), which is fully compliant to the IEEE LOM eLearning object metadata standard. Enabled through an advanced authoring toolset, hylOs allows the definition of instructional overlays of a given eLearning object mesh.Design/methodology/approachIn educational content management, simple file distribution is considered insufficient. Instead, IEEE LOM standardised eLearning objects have been well established as the basic building blocks for educational online content. They are nicely suited for self‐explorative learning approaches within adaptive hypermedia applications. Even though eLearning objects typically reside within content repositories, they may propagate metadata relations beyond repository limits. Given the explicit meaning of these interobject references, a semantic net of content strings can be knotted, overlaying the repository infrastructure.FindingsBased on a newly introduced ontological evaluation layer, meaningful overlay relations between knowledge objects are shown to derive autonomously. A technology framework to extend the resulting semantic nets beyond repository limits is also presented.Research limitations/implicationsThis paper provides proof of concept for the derivation and use of semantic content networks in educational hypermedia. It thereby opens up new directions for future eLearning technologies and pedagogical adoption.Practical implicationsThe paper illustrates capabilities of the hylOs eLearning content management. The hylOs is built upon the more general Media Information Repository (MIR) and the MIR Adaptive Context Linking Environment (MIRaCLE): its linking extension. MIR is an open system supporting the standard XML, CORBA and JNDI. hylOs benefits from manageable information structures, sophisticated access logic and high‐level authoring tools like the eLO editor responsible for the semi‐manual creation of meta data and WYSIWYG like XML–content editing, allowing for rapid distributed content development.Originality/valueOver the last few years, networking technologies and distributed information systems have moved up the OSI layer and are established well within application‐centric middleware. Most recently, content overlay networks have matured, incorporating the semantics of data files into their self‐organisational structure with the aim of optimising data‐centric distributed indexing and retrieval. This paper elaborates a corresponding concept of semantic structuring for educational content objects. It introduces and analyses the autonomous generation and educational exploitation of semantic content nets, providing proof of concept by a full‐featured implementation within the hylOs educational content management system.
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Kocher, Idrees Sarhan. "AN EXPERIMENTAL SIMULATION OF ADDRESSING AUTO-CONFIGURATION ISSUES FOR WIRELESS SENSOR NETWORKS". Academic Journal of Nawroz University 10, nr 4 (25.11.2021): 1–13. http://dx.doi.org/10.25007/ajnu.v10n4a957.
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Wireless Sensor Networks (WSN) is now an evolving technology and has a broad range of applications, such as battlefield surveillance, traffic surveillance, detection of forest fires, detection of floods, etc. The communication nature of the wireless sensor network is unprotected and dangerous due to deployment in hostile environments, restricted resources, an automatic nature, and untrusted media for broadcast transmission. For wireless sensor networks, several routing protocols have been suggested, but none of them have been developed with protection as a target. The majority function in routing algorithms currently in place for sensor networks optimize a restricted capacities in sensor nodes and the application based design of WSNs. A WSNs, however, are exposed to a number of possible threats that impede the network's regular activity. Thus, there is a strong need to provide the routing protocols of the OSI structure layer with a safe mechanism to prevent an attacker from obstructing it.
The well-known attacks against all layers are discussed in this systematic roadmap, and debilitating attacks against routing protocols are analyzed and defined in particular. Several suggested attack countermeasures, design considerations and paper contributions are also included in the routing protocols. The assertion of the study is that WSN routing protocols must be built with protection in mind, and this is the only efficient solution in WSNs for safe routing. The aim of this paper is also to provide problems, attacks and countermeasures related to protection. Finally, it is hoped that this roadmap would inspire potential researchers to come up with smarter and better protection measures and make their network safer.
The first such research analysis of secure routing protocols in WSNs is this roadmap study.
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Davison, Wayne. "OSI upper layers support for applications". Library Hi Tech 8, nr 4 (kwiecień 1990): 33–42. http://dx.doi.org/10.1108/eb047806.
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Alasri, Abbas, i Rossilawati Sulaiman. "Protection of XML-Based Denail-of-Service and Httpflooding Attacks in Web Services Using the Middleware Tool". International Journal of Engineering & Technology 7, nr 4.7 (27.09.2018): 322. http://dx.doi.org/10.14419/ijet.v7i4.7.20570.
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A web service is defined as the method of communication between the web applications and the clients. Web services are very flexible and scalable as they are independent of both the hardware and software infrastructure. The lack of security protection offered by web services creates a gap which attackers can make use of. Web services are offered on the HyperText Transfer Protocol (HTTP) with Simple Object Access Protocol (SOAP) as the underlying infrastructure. Web services rely heavily on the Extended Mark-up Language (XML). Hence, web services are most vulnerable to attacks which use XML as the attack parameter. Recently, a new type of XML-based Denial-of-Service (XDoS) attacks has surfaced, which targets the web services. The purpose of these attacks is to consume the system resources by sending SOAP requests that contain malicious XML content. Unfortunately, these malicious requests go undetected underneath the network or transportation layers of the Transfer Control Protocol/Internet Protocol (TCP/IP), as they appear to be legitimate packets.In this paper, a middleware tool is proposed to provide real time detection and prevention of XDoS and HTTP flooding attacks in web service. This tool focuses on the attacks on the two layers of the Open System Interconnection (OSI) model, which are to detect and prevent XDoS attacks on the application layer and prevent flooding attacks at the Network layer.The rule-based approach is used to classify requests either as normal or malicious,in order to detect the XDoS attacks. The experimental results from the middleware tool have demonstrated that the rule-based technique has efficiently detected and prevented theattacks of XDoS and HTTP flooding attacks such as the oversized payload, coercive parsing and XML external entities close to real-time such as 0.006s over the web services. The middleware tool provides close to 100% service availability to normal request, hence protecting the web service against the attacks of XDoS and distributed XDoS (DXDoS).\
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Pestin, Maxim S., i Alexander S. Novikov. "Simulation model of wireless ad-hoc network to study algorithms of traffic routing". Journal Of Applied Informatics 17, nr 4 (31.08.2022): 75–86. http://dx.doi.org/10.37791/2687-0649-2022-17-4-75-86.
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Communication network simulators are software designed to model, explore, test and debug network technologies, including wireless decentralized self-organizing networks or ad-hoc networks. They greatly simplify the research, development and optimization of routing protocols in these networks. However, the well-known simulators have a number of disadvantages, including the difficulty of adding custom extensions to ad-hoc network routing protocols, the lack of the necessary network stack, the lack of routing algorithm visualization modes, low performance, and difficulty in debugging communication protocols. The purpose of this work is to create a simulation model of a wireless network that would allow us to explore, debug and evaluate the developed algorithms and routing protocols for ad-hoc networks. At the same time, the requirements for interface ergonomics and the ability to visualize the operation of algorithms, ensure the collection of statistics, and create various scenarios for the operation of the network come to the fore. The article proposes the structure of the simulation model, which includes the modules of the network subscriber, application software, network layer of the OSI data transmission model, radio module, radio transmission environment, statistics collection, visualization and scenario management. To solve the tasks set, the approach of discrete-event modeling was used. To create a simulator of wireless decentralized networks and routing algorithms, a set of classes was developed that implement the modules of the simulation model. Based on the proposed structure, module classes and discrete event simulation algorithm, a software implementation of the simulation model was created using the C++ programming language and the Qt framework. The developed simulation model was used in the course of an experimental study of the effectiveness of the network routing algorithm. The proposed software will simplify the development and debugging of algorithms and routing protocols for ad-hoc networks.
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Snellen, David. "DECnet/OSI (part 2)". International Journal of Network Management 2, nr 1 (marzec 1992): 18–27. http://dx.doi.org/10.1002/nem.4560020106.
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Rao, Gottapu Sankara, i P. Krishna Subbarao. "A Novel Approach for Detection of DoS / DDoS Attack in Network Environment using Ensemble Machine Learning Model". International Journal on Recent and Innovation Trends in Computing and Communication 11, nr 9 (27.10.2023): 244–53. http://dx.doi.org/10.17762/ijritcc.v11i9.8340.
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One of the most serious threat to network security is Denial of service (DOS) attacks. Internet and computer networks are now important parts of our businesses and daily lives. Malicious actions have become more common as our reliance on computers and communication networks has grown. Network threats are a big problem in the way people communicate today. To make sure that the networks work well and that users' information is safe, the network data must be watched and analysed to find malicious activities and attacks. Flooding may be the simplest DDoS assault. Computer networks and services are vulnerable to DoS and DDoS attacks. These assaults flood target systems with malicious traffic, making them unreachable to genuine users. The work aims to enhance the resilience of network infrastructures against these attacks and ensure uninterrupted service delivery. This research develops and evaluates enhanced DoS/DDoS detection methods. DoS attacks usually stop or slow down legal computer or network use. Denial-of-service (DoS) attacks prevent genuine users from accessing and using information systems and resources. The OSI model's layers make up the computer network. Different types of DDoS strikes target different layers. The Network Layer can be broken by using ICMP Floods or Smurf Attacks. The Transport layer can be attacked using UDP Floods, TCP Connection Exhaustion, and SYN Floods. HTTP-encrypted attacks can be used to get through to the application layer. DoS/DDoS attacks are malicious attacks. Protect network data from harm. Computer network services are increasingly threatened by DoS/DDoS attacks. Machine learning may detect prior DoS/DDoS attacks. DoS/DDoS attacks proliferate online and via social media. Network security is IT's top priority. DoS and DDoS assaults include ICMP, UDP, and the more prevalent TCP flood attacks. These strikes must be identified and stopped immediately. In this work, a stacking ensemble method is suggested for detecting DoS/DDoS attacks so that our networked data doesn't get any worse. This paper used a method called "Ensemble of classifiers," in which each class uses a different way to learn. In proposed methodology Experiment#1 , I used the Home Wifi Network Traffic Collected and generated own Dataset named it as MywifiNetwork.csv, whereas in proposed methodology Experiment#2, I used the kaggle repository “NSL-KDD benchmark dataset” to perform experiments in order to find detection accuracy of dos attack detection using python language in jupyter notebook. The system detects attack-type or legitimate-type of network traffic during detection ML classification methods are used to compare how well the suggested system works. The results show that when the ensembled stacking learning model is used, 99% of the time it is able to find the problem. In proposed methodology two Experiments are implemented for comparing detection accuracy with the existing techniques. Compared to other measuring methods, we get a big step forward in finding attacks. So, our model gives a lot of faith in securing these networks. This paper will analyse the behaviour of network traffics.
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Певнев, Володимир Якович, Володимир Володимирович Торяник i Вячеслав Сергійович Харченко. "КІБЕРБЕЗПЕКА БЕЗПРОВОДОВИХ СМАРТ-СИСТЕМ: КАНАЛИ ВТРУЧАНЬ ТА РАДІОЧАСТОТНІ ВРАЗЛИВОСТІ". RADIOELECTRONIC AND COMPUTER SYSTEMS, nr 4 (27.11.2020): 79–92. http://dx.doi.org/10.32620/reks.2020.4.07.
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The subject of this study is the radio frequency cyber vulnerability of information and control interaction technology in the wireless smart systems (WSS). WSS is the cyber-physical systems, that operate within the OSI model. The specificity and specialization of these systems are determined by radio technologies of the physical layer. For example, the Internet of Things (IoT, including medical IoMT), the Internet of Drones (IoD), systems for aviation monitoring ADS-B and traffic management ATM, and, in the future, the Internet of Everything (IoE) - all are types of WSS. The aim is to analyze the radio frequency parameters of information and control interaction in the WSS to identify possible radio frequency cyber vulnerabilities in the WSS. Objectives: summarize and systematize the physical and functional parameters of wireless technologies in the ISM (Industrial Scientific & Medical Band) and SRD (Short range devices) ranges, which are significant from the WSS radiofrequency cyber vulnerability perspective, including navigation technologies; analyze trends and methods of successful cyber attacks on the WSS; carry out expert assessments of potential WSSs cyber vulnerabilities depending on their architecture and application area. The methods used: analysis of trends in known radiofrequency incidents and expert assessments of the cyber vulnerability of the WSS information and control interaction channels. The following results were obtained: 12 actual WSS radio technologies were analyzed. 6 types of possible radio frequency cyber attacks on the WSS were typified. The expert assessment of the probability of exploiting vulnerabilities by ranges, radio technologies, and attack type was made. The special danger of high-tech targeted APT attacks, as well as the high potential radio vulnerability of cyber-physical systems, was shown. The cyber vulnerability of ADS-B aircraft systems was especially noted. Conclusions. The scientific novelty of the results obtained is as follows: a trend of APT attacks cost reduction and an increase in the probability of their implementation through the new capabilities of SDR technology (Software Defined Radio) were revealed. The possibility of a controlled SDR compromising of the security parameters of WSS channels in any radio range was shown. A promising direction of research was proposed - SDR-penetration testing of WSS.
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Tardo, J. "Standardizing cryptographic services at OSI higher layers". IEEE Communications Magazine 23, nr 7 (lipiec 1985): 25–29. http://dx.doi.org/10.1109/mcom.1985.1092610.
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Yuliia, KOSTIUK, i SHESTAK Yaroslav. "THE TRANSPORT LAYER OF THE ISO/OSI MODEL IN COMPUTER NETWORKS". INTERNATIONAL SCIENTIFIC-PRACTICAL JOURNAL "COMMODITIES AND MARKETS" 40, nr 4 (22.12.2021): 49–58. http://dx.doi.org/10.31617/tr.knute.2021(40)05.
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Background. The transport layer is designed to deliver data without errors, losses and duplication in the order in which they were transmitted. It provides data transfer between two applications with the required level of reliability. Transport layer protocols, which guarantee reliable data delivery, establish a virtual connection before data exchange and resend segments in case of loss or damage. The aim of the study was to determine the role of transport security protocols in computer networks. Materials and methods. To achieve the goal, the study used statistical analysis and a systematic approach. Results. TCP provides reliable message transmission through the formation of logical connections, while allowing peers on the sending computer and the receiving computer to support data exchange in duplex mode. It also has the ability to seamlessly send a byte stream generated on one of the computers to any other computer connected to the network.In addition, TCP controls the connection load, UDP does not control anything but the integrity of the received datagrams. Conclusion. The difference between TCP and UDP is the so-called "delivery guarantee". TCP requires a response from the client to whom the data packet is delivered, confirmation of delivery, and for this he needs a pre-established connection. TCP is also considered reliable, unlike UDP, which is called "unreliable datagram protocol". TCP eliminates data loss, duplication and shuffling of packets, delays, UDP allows all this, and it does not need a connection to work., as a result of which the data is transferred on UDP, should manage received, even with losses.
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Snellen, David. "Decnet/osi protocols: The physical, data link and network layers". International Journal of Network Management 1, nr 2 (grudzień 1991): 82–95. http://dx.doi.org/10.1002/nem.4560010205.
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Solikhin, Imam. "Desain Aplikasi Pedataan Pasien Pada Puskesmas Tugu Jaya Kabupaten OKI". Jurnal Ilmiah Betrik 8, nr 03 (30.01.2017): 166–74. http://dx.doi.org/10.36050/betrik.v8i03.77.
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Puskesmas Tugu Jaya is a government institution that serves the public health either having a small economy or the economy up. The Puskesmas in the patient's data collection system is still done through a manual process (through paper writing) then typed in a computer using Ms.Office). The process of data collection like this is less efficient because the process of repetition is done repeatedly so long time. The process of storing, searching and reporting patient data that often occurs difficult because employees have to look for in one place. Solutions to overcome these problems by proposing the design of patient data collection application at Tugu Jaya Community Health Center of OKI-based computerized. The design of this application can be developed so that the patient data collection system at Tugu Jaya Puskesmas OKI Regency is more efficient in its processing compared to the current manual system running today. In this pedesainan need an application development method (software) in the form of linear sequential model to finish the phases to produce a design that later can dikembangankan into computerized applications. Application development is expected to be able to perform pakanendan data processing pembutan report quickly, precisely, and accurately.
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Ahdarrijal, Yujitia, i Ulung Pribadi. "Community Satisfaction with Online Services in East Lombok Regency: (Case Study: BAKSO Application)". Scientific Journal of Informatics 11, nr 1 (29.02.2024): 95–106. http://dx.doi.org/10.15294/sji.v11i1.48083.
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Purpose: This study analyzes the use of the BAKSO (Create Online Population Administration) application for users, namely employees of the East Lombok Regency Population and Civil Registration Office and the Admin of each village. The measurement uses variables consisting of infrastructure, ICT, bureaucracy, leadership, and implementation of digital government.Methods: The method used is a quantitative type, primary data in the form of a survey of 115 respondents from East Lombok Regency Population and Civil Registration Office office employees and village admins who used the BAKSO application (Create Online Population Administration). Using the Likert Scale (1: strongly disagree, 2: disagree, 3: neutral, 4: agree, and 5: strongly agree). The analysis technique for this study uses SmartPLS 3.Results: The results of this study show that infrastructure and ICT variables have a positive and significant influence on the implementation of digital government in the implementation of the BAKSO application. Meanwhile, bureaucratic and leadership variables have little impact and are substantial in implementing the BAKSO application in East Lombok Regency.Novelty: This study is unique because it examines users who are also employees who use the BAKSO application (Make Online Population Administration) with a measuring indicator, namely the online service index (OSI); most of the previous research on this theory was only oriented to assessing public satisfaction with online services. This research provides a new perspective on using the Online Service Index (OSI) on the scope of application-based online services from an employee perspective. In addition, the empirical contribution lies in the professionalism of employees in using the BAKSO application. So that later, it can provide space for the government to pay attention to human resources in running Online Service Index (OSI)-based application services.
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Jiang, W., G. He, T. Long i Y. Ni. "DETECTING WATER BODIES IN LANDSAT8 OLI IMAGE USING DEEP LEARNING". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3 (30.04.2018): 669–72. http://dx.doi.org/10.5194/isprs-archives-xlii-3-669-2018.
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Water body identifying is critical to climate change, water resources, ecosystem service and hydrological cycle. Multi-layer perceptron(MLP) is the popular and classic method under deep learning framework to detect target and classify image. Therefore, this study adopts this method to identify the water body of Landsat8. To compare the performance of classification, the maximum likelihood and water index are employed for each study area. The classification results are evaluated from accuracy indices and local comparison. Evaluation result shows that multi-layer perceptron(MLP) can achieve better performance than the other two methods. Moreover, the thin water also can be clearly identified by the multi-layer perceptron. The proposed method has the application potential in mapping global scale surface water with multi-source medium-high resolution satellite data.
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Shen, Lu, Daniel J. Jacob, Xiong Liu, Guanyu Huang, Ke Li, Hong Liao i Tao Wang. "An evaluation of the ability of the Ozone Monitoring Instrument (OMI) to observe boundary layer ozone pollution across China: application to 2005–2017 ozone trends". Atmospheric Chemistry and Physics 19, nr 9 (17.05.2019): 6551–60. http://dx.doi.org/10.5194/acp-19-6551-2019.
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Abstract. Nadir-viewing satellite observations of tropospheric ozone in the UV have been shown to have some sensitivity to boundary layer ozone pollution episodes, but so far they have not yet been compared to surface ozone observations collected by large-scale monitoring networks. Here we use 2013–2017 surface ozone data from China's new Ministry of Ecology and Environment (MEE) network of ∼ 1000 sites, together with vertical profiles from ozonesondes and aircraft, to quantify the ability of tropospheric ozone retrievals from the Ozone Monitoring Instrument (OMI) and to detect boundary layer ozone pollution in China. We focus on summer when ozone pollution in China is most severe and when OMI has the strongest sensitivity. After subtracting the Pacific background, we find that the 2013–2017 mean OMI ozone enhancements over eastern China have strong spatial correlation with the corresponding multiyear means in the surface afternoon observations (R=0.73), and that OMI can estimate these multiyear means in summer afternoon surface ozone with a precision of 8 ppb. The OMI data show significantly higher values on observed surface ozone episode days (>82 ppb) than on non-episode days. Day-to-day correlations with surface ozone are much weaker due to OMI noise and are stronger for sites in southern China (<34∘ N; R=0.3–0.6) than in northern China (R=0.1–0.3) because of weaker retrieval sensitivity and larger upper tropospheric variability in the north. Ozonesonde data show that much of the variability of OMI ozone over southern China in summer is driven by the boundary layer. Comparison of 2005–2009 and 2013–2017 OMI data indicates that mean summer afternoon surface ozone in southern China (including urban and rural regions) has increased by 3.5±3.0 ppb over the 8-year period and that the number of episode days per summer has increased by 2.2±0.4 (as diagnosed by an extreme value model), generally consistent with the few long-term surface records. Ozone increases have been particularly large in the Yangtze River Delta and in the Hubei, Guangxi and Hainan provinces.
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Hafizhah, Annisa, Firmansyah Firmansyah i Addys Aldizar. "Practice of Buying and Selling Services Using the Instagram Application". Jurnal Ekonomi dan Perbankan Syariah 10, nr 2 (31.10.2022): 181–94. http://dx.doi.org/10.46899/jeps.v10i2.366.
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This study aims to review fiqh on the practice of buying and selling transactions using deposit services on the Instagram application according to contemporary scholars, namely Erwandi Tarmizi, and Oni Sahroni This research uses the descriptive analysis method. Collecting data through interviews and literature study. The results of this study indicate that buying and selling transactions using deposit services on the Instagram application are viewed from the view of contemporary cleric Dr. Erwandi Tarmizi, MA, and Dr. Oni Sahroni, MA is allowed if the custodian pays first and then delivers the goods later.
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Fedkin, Nikita M., Can Li, Nickolay A. Krotkov, Pascal Hedelt, Diego G. Loyola, Russell R. Dickerson i Robert Spurr. "Volcanic SO<sub>2</sub> effective layer height retrieval for the Ozone Monitoring Instrument (OMI) using a machine-learning approach". Atmospheric Measurement Techniques 14, nr 5 (20.05.2021): 3673–91. http://dx.doi.org/10.5194/amt-14-3673-2021.
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Abstract. Information about the height and loading of sulfur dioxide (SO2) plumes from volcanic eruptions is crucial for aviation safety and for assessing the effect of sulfate aerosols on climate. While SO2 layer height has been successfully retrieved from backscattered Earthshine ultraviolet (UV) radiances measured by the Ozone Monitoring Instrument (OMI), previously demonstrated techniques are computationally intensive and not suitable for near-real-time applications. In this study, we introduce a new OMI algorithm for fast retrievals of effective volcanic SO2 layer height. We apply the Full-Physics Inverse Learning Machine (FP_ILM) algorithm to OMI radiances in the spectral range of 310–330 nm. This approach consists of a training phase that utilizes extensive radiative transfer calculations to generate a large dataset of synthetic radiance spectra for geophysical parameters representing the OMI measurement conditions. The principal components of the spectra from this dataset in addition to a few geophysical parameters are used to train a neural network to solve the inverse problem and predict the SO2 layer height. This is followed by applying the trained inverse model to real OMI measurements to retrieve the effective SO2 plume heights. The algorithm has been tested on several major eruptions during the OMI data record. The results for the 2008 Kasatochi, 2014 Kelud, 2015 Calbuco, and 2019 Raikoke eruption cases are presented here and compared with volcanic plume heights estimated with other satellite sensors. For the most part, OMI-retrieved effective SO2 heights agree well with the lidar measurements of aerosol layer height from Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) and thermal infrared retrievals of SO2 heights from the infrared atmospheric sounding interferometer (IASI). The errors in OMI-retrieved SO2 heights are estimated to be 1–1.5 km for plumes with relatively large SO2 signals (>40 DU). The algorithm is very fast and retrieves plume height in less than 10 min for an entire OMI orbit.
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Levelt, Pieternel F., Joanna Joiner, Johanna Tamminen, J. Pepijn Veefkind, Pawan K. Bhartia, Deborah C. Stein Zweers, Bryan N. Duncan i in. "The Ozone Monitoring Instrument: overview of 14 years in space". Atmospheric Chemistry and Physics 18, nr 8 (24.04.2018): 5699–745. http://dx.doi.org/10.5194/acp-18-5699-2018.
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Abstract. This overview paper highlights the successes of the Ozone Monitoring Instrument (OMI) on board the Aura satellite spanning a period of nearly 14 years. Data from OMI has been used in a wide range of applications and research resulting in many new findings. Due to its unprecedented spatial resolution, in combination with daily global coverage, OMI plays a unique role in measuring trace gases important for the ozone layer, air quality, and climate change. With the operational very fast delivery (VFD; direct readout) and near real-time (NRT) availability of the data, OMI also plays an important role in the development of operational services in the atmospheric chemistry domain.
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Huening, Felix, Holger Heuermann, Franz-Josef Wache i Rami Audisho Jajo. "A new wireless sensor interface using dual-mode radio". Journal of Sensors and Sensor Systems 7, nr 2 (21.09.2018): 507–15. http://dx.doi.org/10.5194/jsss-7-507-2018.
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Abstract. The integration of sensors is one of the major tasks in embedded, control and “internet of things” (IoT) applications. For the integration mainly digital interfaces are used, starting from rather simple pulse-width modulation (PWM) interface to more complex interfaces like CAN (Controller Area Network). Even though these interfaces are tethered by definition, a wireless realization is highly welcome in many applications to reduce cable and connector cost, increase the flexibility and realize new emerging applications like wireless control systems. Currently used wireless solutions like Bluetooth, WirelessHART or IO-Link Wireless use dedicated communication standards and corresponding higher protocol layers to realize the wireless communication. Due to the complexity of the communication and the protocol handling, additional latency and jitter are introduced to the data communication that can meet the requirements for many applications. Even though tunnelling of other bus data like CAN data is generally also possible the latency and jitter prevent the tunnelling from being transparent for the bus system. Therefore a new basic technology based on dual-mode radio is used to realize a wireless communication on the physical layer only, enabling a reliable and real-time data transfer. As this system operates on the physical layer it is independent of any higher layers of the OSI (open systems interconnection) model. Hence it can be used for several different communication systems to replace the tethered physical layer. A prototype is developed and tested for real-time wireless PWM, SENT (single-edge nibble transmission) and CAN data transfer with very low latency and jitter.
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Hayashi, Takahiro, i Ken Ishihara. "OS6-13 Generation of Narrow Band Elastic Wave with a Fiber Laser and its Application to the Scanning Laser Source Technique(Ultrasonic NDT of Cracks and Damages (2),OS6 Ultrasonic non-destructive testing and evaluation,MEASUREMENT METHODS)". Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2015.14 (2015): 84. http://dx.doi.org/10.1299/jsmeatem.2015.14.84.
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Castanheiro, L. F., A. M. G. Tommaselli, M. V. Machado, G. H. Santos, I. S. Norberto i T. T. Reis. "THE USE OF A WIDE FOV LASER SCANNING SYSTEM AND A SLAM ALGORITHM FOR MOBILE APPLICATIONS". International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B1-2022 (30.05.2022): 181–87. http://dx.doi.org/10.5194/isprs-archives-xliii-b1-2022-181-2022.
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Abstract. This paper presents the assessment of a wide-angle laser scanner and a simultaneous localisation and mapping (SLAM) algorithm to estimate the trajectory and generate a 3D map of the environment. A backpack platform composed of an OS0-128 Ouster (FoV 90° × 360°) laser scanner was used to acquire laser data in an area with urban and forest features. Web SLAM, an online SLAM algorithm implemented by Ouster, Inc., was used to estimate the trajectory and generate a 3D map in a local reference system. Then, the 3D point clouds were transformed into the ground coordinate system with a rigid body transformation. Three datasets were used: (I) the entire trajectory consisting of forwarding and backwards paths, (II) only forward path, and (III) only backward path. Visual analysis showed a double mapping error in the point cloud of dataset I. Therefore, the point cloud registration was performed only for datasets II and III, achieving a centimetric accuracy, which is compatible with the OS0-128 laser scanner accuracy (∼5cm).
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Gong, Shun, Hai Jin, Danfeng Zhang, Wei Zou, Chunhui Wang, Zhenxing Li, Rongbin Chen, Yan Dong i Lijun Hou. "The Therapeutic Effects after Transplantation of Whole-Layer Olfactory Mucosa in Rats with Optic Nerve Injury". BioMed Research International 2018 (2018): 1–8. http://dx.doi.org/10.1155/2018/6069756.
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Background. Existing evidence suggests the potential therapy of transplanting olfactory ensheathing cells (OEC) either alone or in combination with neurotrophic factors or other cell types in optic nerve injury (ONI). However, clinical use of autologous OEC in the acute stages of ONI is not possible. On the other hand, acute application of heterologous transplantation may bring the issue of immune rejection. The olfactory mucosa (OM) with OEC in the lamina propria layer is located in the upper region of the nasal cavity and is easy to dissect under nasal endoscopy, which makes it a candidate as autograft material in acute stages of ONI. To investigate the potential of the OM on the protection of injured neurons and on the promotion of axonal regeneration, we developed a transplantation of syngenic OM in rats with ONI model. Methods. After the right optic nerve was crushed in Lewis rats, pieces of syngenic whole-layer OM were transplanted into the lesion. Rats undergoing phosphate buffered saline (PBS) injection were used as negative controls (NC). The authors evaluated the regeneration of retinal ganglion cells (RGCs) and axons for 3, 7, 14, and 28 days after transplantation. Obtained retinas and optic nerves were analyzed histologically. Results. Transplantations of OM significantly promoted the survival of retinal ganglion cells (RGCs) and axonal growth of RGCs compared with PBS alone. Moreover, OM group was associated with higher expression of GAP-43 in comparison with the PBS group. In addition to the potential effects on RGCs, transplantations of OM significantly decreased the expression of GFAP in the retinas, suggesting inhibiting astrocyte activation. Conclusions. Transplantation of whole-layer OM in rats contributes to the neuronal survival and axon regeneration after ONI.
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Zhao, Yu, Thierry Camps, Véronique Bardinal i Julien Perchoux. "Optical Feedback Interferometry Based Microfluidic Sensing: Impact of Multi-Parameters on Doppler Spectral Properties". Applied Sciences 9, nr 18 (18.09.2019): 3903. http://dx.doi.org/10.3390/app9183903.
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As a compact and simple sensing technique, optical feedback interferometry (OFI) can be a promising flowmetry method in various microfluidic applications. In this paper, OFI-based flowmetry sensor performance in a microscale flow scheme is studied theoretically and experimentally. An innovating model and different numerical methods are investigated, where the scattering light angle distribution is involved to predict the Doppler frequency distribution. For the first time, our model describes the influences of multiple OFI sensor system characteristics, such as flowing particle size, concentration, channel interface reflectivity and channel dimension, on the OFI signal spectral performances. In particular, a significant OFI signal level enhancement was achieved by deposing a high reflectivity gold layer on the rear channel interface due to the increased forward scattered light reflection. The consistent experimental validation associated with the simulations verifies this numerical simulation method’s reliability. The numerical methods presented here provide a new tool to design novel microfluidic reactors and sensors.
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Sundarabalan, B., i P. Shanmugam. "Modelling of underwater light fields in turbid and eutrophic waters: application and validation with experimental data". Ocean Science Discussions 11, nr 5 (15.09.2014): 2119–72. http://dx.doi.org/10.5194/osd-11-2119-2014.
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Abstract. A reliable radiative transfer model is an essential and indispensable tool for understanding of the radiative transfer processes in homogenous and layered waters, analyzing measurements made by radiance sensors and developing remote sensing algorithms to derive meaningful physical quantities and biogeochemical variables in turbid and productive coastal waters. Existing radiative transfer models have been designed to be applicable to either homogenous waters or inhomogeneous waters. To overcome such constraints associated with these models, this study presents a radiative transfer model that treats a homogenous layer as a diffuse part and an inhomogeneous layer as a direct part in the water column and combines these two parts appropriately in order to generate more reliable underwater light field data such as upwelling radiance (Lu), downwelling irradiance (Ed) and upwelling irradiance (Eu). The diffuse model assumes the inherent optical properties (IOPs) to be vertically continuous and the light fields to exponentially decrease with the depth, whereas the direct part considers the water column to be vertically inhomogeneous (layer-by-layer phenomena) with the vertically varying phase function. The surface and bottom boundary conditions, source function due to chlorophyll and solar incident geometry are also included in the present RT model. The performance of this model is assessed in a variety of waters (clear, turbid and eutrophic) using the measured radiometric data. The present model shows an advantage in terms of producing accurate Lu, Ed and Eu profiles (in spatial domain) in different waters determined by both homogenous and inhomogeneous conditions. The feasibility of predicting these underwater light fields based on the remotely estimated IOP data is also examined using the present RT model. For this application, vertical profiles of the water constituents and IOPs are estimated by empirical models based on our in-situ data. The present RT model generates Lu, Ed and Eu spectra closely consistent with the measured data. These results lead to a conclusion that the present RT model is a viable alternative to existing RT models and has an important implication for remote sensing of optically complex waters.
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Silva, Bernardo B. da, Alexandra C. Braga, Célia C. Braga, Leidjane M. M. de Oliveira, Suzana M. G. L. Montenegro i Bernardo Barbosa Junior. "Procedures for calculation of the albedo with OLI-Landsat 8 images: Application to the Brazilian semi-arid". Revista Brasileira de Engenharia Agrícola e Ambiental 20, nr 1 (styczeń 2016): 3–8. http://dx.doi.org/10.1590/1807-1929/agriambi.v20n1p3-8.
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ABSTRACT The surface albedo plays an important role in the exchanges of energy and mass in the planetary boundary layer. Therefore, changes in albedo affect the balance of radiation and energy at the surface, which can be detected with its monitoring. Albedo determination has been performed through various sensors, but there is not yet any publication dealing with albedo calculation procedures using OLI (Operational Land Imager) - Landsat 8 images. The objective of the study is to present the procedures for computing the albedo with OLI images and map it in irrigated areas of the São Gonçalo Irrigated District, PB, Brazil. Images of the year 2013, path 215 and row 65, were selected. The data necessary for calculating the albedo were extracted from each image metadata: additive and multiplicative terms of radiance and reflectance, and sun elevation angle. There were large differences between the albedo values of irrigated plots, water bodies and native vegetation. The albedo obtained with OLI images provides a higher degree of differentiation of the various types of land use, due to the substantial increase in the radiometric resolution of this new sensor.