• 융합신호처리학회논문지
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• 제12권2호
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• pp.119-127
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• 2011

The paper surveys various analytical models for IEEE 802.11 medium access control protocols and critically discusses recent issues developing in wireless mobile ad hoc networks and their MACs. The surveyed MAC protocols include the standard IEEE 802.11 MAC suites such as IEEE 802.11 DCF, IEEE 802.11 PCF, IEEE 802.11e EDCA, and IEEE 802.11 ad hoc mode; and also the newer, de facto MAC protocols. We study the analytic models of the standard MAC suites followed by the newer analytic models that have been published in recent years. Also, the paper tries to include most of current literatures discussing analytic modeling of MAC in conjunction to some critical issues such as contention among ad hoc nodes, hidden terminal problems, and real-time service support.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 봄 학술발표논문집 Vol.30 No.1 (C)
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• pp.331-333
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• 2003

본 논문에서는 802.11을 기반으로 한 무선 링크에서 인터넷 상의 대표적인 전송계층 프로토콜인 TCP(Transmission Control Protocol)와 HDP(User Datagram Protocol)의 성능을 비교한다. 또한 이들 프로토콜이 무선 환경에서 보이는 문제점을 지적하고 원인을 분석한다. 무선 네트워크의 용량은 유선 네트워크와 다르며, 따라서 유선 네트워크 용량을 기반으로 설계된 TCP는 불안정하게 작동한다. 본 논문에서는 주목할만한 전송 프로토콜의 병목현상을 나타내는 원인으로 MAC(Medium Access Control)에 의해 채널을 잡기 위한 경쟁이 심각함과 전송 계층 프로토콜의 네트워크 용량 예측이 올바르지 않음을 지적하고, TCP와 HDP를 비교하여 무선 망에서도 네트워크 상황에 적응하는 기법이 중요함을 확인한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.52.3-52
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• 2001

There are some problems to implement a realtime network system with Ethernet because the MAC(Medium Access Control) of Ethernet uses a CSMA/CD protocol, which introduces unexpected delays. In this paper, we designed a method to solve problems due to the Ethernet MAC. This method introduces a pseudo-MAC in application layer to support the real-time feature. So the presented method doesn´t need any modifications of protocols such as UDP/IP/MAC. The presented pseudo-MAC is based on both a token passing protocol and a publisher-subscriber protocol. The suggested realtime protocol is implemented and tested practically in a local area network. The proposed real-time network consists of a token controller node and general nodes.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 춘계학술발표대회
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• pp.1021-1023
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• 2012

본 논문에서는 UWB 기술 기반 WiMedia Distributed Medium Access Control (D-MAC) 표준 프로토콜에 적용할 수 있는 Satisfaction of QoS (SoQ) 기반 협력 통신 프로토콜을 제안한다. 이를 위해 UWB 링크 전송 속도와 QoS 척도에 따른 릴레이 노드 선정 알고리즘을 제안한다. 본 논문에서 제안하는 SoQ 기반 협력 통신 프로토콜은 분산적인 D-MAC 표준 기술과 호환성을 갖고, 각 디바이스에서 독립적으로 실행되는 SoQ 기반 Relay Node Selection (RNS) 기준에 따라 실행된다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 춘계학술발표대회
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• pp.1024-1026
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• 2012

본 논문에서는 UWB 기술 기반 WiMedia Distributed Medium Access Control (D-MAC) 프로토콜에서, 디바이스들의 이동성으로 인해 발생하는 Distributed Reservation Protocol (DRP) 예약 충돌 현상을 분석한다. 그리고 DRP 예약 충돌 시 발생하는 성능 저하를 감소시키기 위해 DRP Conflict Resolution 방식과 DRP 릴레이 통신 기술을 제안한다. 본 논문에서 제안하는 DRP 릴레이 통신 프로토콜은 충돌대상 디바이스에게 예약된 자원을 유지할 수 있도록 Direct Link 뿐만 아니라, DRP 예약 충돌 시 릴레이 노드를 경유하여 또 다른 Indirect Link 링크를 빠르게 예약할 수 있는 분산적인 자원 예약 프로토콜을 제안한다.

• International Journal of Computer Science & Network Security
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• 제21권12호
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• pp.280-292
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• 2021

Enterprise Resource Planning (ERP) is a software that manages and automate the internal processes of an organization. Process speed and quality can be increased, and cost reduced by process automation. Odoo is an open source ERP platform including more than 15000 apps. ERP systems such as Odoo are all-in-one management systems. Odoo can be suitable for small and medium organizations, but duo to efficiency limitations, Odoo is not suitable for the large ones. Furthermore, Odoo can be implemented on both local or public servers in which each has some advantages and disadvantages such as; the speed of internet, synced data or anywhere access. In many cases, there is a persistent need to have more than one synchronized Odoo instance in several physical places. We modified Odoo to support this kind of requirements and improve its efficiency by replacing its standard database with a distributed one, namely CockroachDB.

• International Journal of Advanced Culture Technology
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• 제9권4호
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• pp.355-362
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• 2021

Through the Korean version of the New Deal 2.0, manufacturing-oriented SMEs are facing a new environmental change called smart factory construction. In addition, SMEs are facing new security threats along with a contactless environment due to COVID-19. However, it is practically impossible to apply the previously researched and developed security management system to protect the core technology of manufacturing-oriented SMEs due to the lack of economic capacity of SMEs. Therefore, through research on security management systems suitable for SMEs, it is necessary to strengthen their business competitiveness and ensure sustainability through proactive responses to security threats faced by SMEs. The security management system presented in this study is a security management system to prevent technology leakage applicable to SMEs by deriving and reflecting the minimum security requirements in consideration of technology protection point of view, smart factory, and remote access in a non-contact environment. It is also designed in a modular form. The proposed security management system is standardized and can be selectively used by SMEs.

• International Journal of Internet, Broadcasting and Communication
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• 제14권1호
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• pp.188-193
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• 2022

The energy efficiency of memory systems is an important task in designing future computer systems as memory capacity continues to increase to accommodate the growing big data. In this article, we present an energy-efficient last-level cache management policy for future mobile systems. The proposed policy makes use of low-power PCM (phase-change memory) as the main memory medium, and reduces the amount of data written to PCM, thereby saving memory energy consumptions. To do so, the policy keeps track of the modified cache lines within each cache block, and replaces the last-level cache block that incurs the smallest PCM writing upon cache replacement requests. Also, the policy considers the access bit of cache blocks along with the cache line modifications in order not to degrade the cache hit ratio. Simulation experiments using SPEC benchmarks show that the proposed policy reduces the power consumption of PCM memory by 22.7% on average without degrading performances.

• International Journal of Computer Science & Network Security
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• 제22권5호
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• pp.284-288
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• 2022

The article analyzes the regulations of current criminal law, which ensures the protection and protection of information relations, offers the optimal model of the system of norms of the Criminal Code of Ukraine, which establishes liability for violation of information. The subject of the article is protected information, which should include information or data, the procedure for access to and distribution of which, regardless of the method of submission, storage or organization, are subject to legal regulation in accordance with laws and regulations. For the purposes of criminal law, information as an object of criminal law protection should be classified on the following grounds: depending on the content: personal or family secrets; information constituting a state secret; data included in the official secret; information that constitutes a professional secret; information that constitutes a commercial, tax, banking secret, and, depending on the medium - documented and undocumented.

• Journal of applied mathematics & informatics
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• 제41권6호
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• pp.1155-1171
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• 2023

This paper investigates a non Markovian M/G/1 queue with retrial policy, different kind of service rates as well as unsatisfied clients which is inspired by an example of a transmission medium access control in wireless communications. The server tends to work continuously until it finds at least one client in the system. The server will begin its maintenance tasks after serving all of the clients and if the system becomes empty. Provisioning periods in regular working periods and maintenance service periods should be evenly divided. Using supplementary variable technique, the amount of clients in the system as well as in the orbit were found. Further few performance measures of the system were demonstrated numerically.