• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1423-1428
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• 2012

In this paper, we investigated an implementation of anti-fire monitoring system based on the RS-485 communication to support local area coverage within a range of 1 Km range. We developed a Multi Point Communication Protocol supporting input/output information processing and control up to 8128 terminal check points, which provides an interface between the anti-fire monitoring system receiver and multiplex transponders. Additionally, a multiplex transponders controller has been designed for the implemented system to comply with the government regulation on fire protection, especially to monitor, report and control 1016 terminal check points within the time limit.

• Journal of the Korea Society for Simulation
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• v.17 no.4
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• pp.199-208
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• 2008

Lately, since Complementary Metal Oxide Semiconductor(CMOS) image sensor system has low power, low cost and been miniaturized, hardware and applied software studies using these strengths are being carrying on actively. However, the products equipped with CMOS image sensor based polling method yet has several problems in degree of completeness of applied software and firmware, compared with hardware’s. CMOS image sensor system has an ineffective synchronous problem due to superfluous message exchange. Also when a sending of data is delayed continually, overhead of re-sending is large. So because of these, it has a problem in structural stability according to Polling Method. In this study, polling cycle was subdivided in high-speed synchronization method of firmware -based through MCU and synchronization method of Stepwise was proposed. Also, re-connection and data sending were advanced more efficiently by using interrupt way. In conclusion, the proposed method showed more than 20 times better performance in synchronization time and error connection. Also, a board was created by using C328R board of CMOS image sensor-based and ATmega128L which has low power, MCU and camera modules of proposed firmware were compared with provided software and analyzed in synchronization time and error connection.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.227-229
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• 2017

In this paper, we propose electronic attendance checking system using a bluetooth beacon in the absence of Wi-Fi or cellular networks. The proposed electronic attendance checking system uses a polling scheme where the administrator sends a request message and the attendees response using a beacon packet. Existing electronic attendance checking system requires a centralized server but the proposed method can check attendance without any external networks.

• The Journal of the Korea Contents Association
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• v.7 no.8
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• pp.66-75
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• 2007

The traditional centralized network management method using the SNMP has problems, such as, increase of communication traffic and severe bottleneck phenomena at the specific manager-node caused by a frequent polling mechanism. Several mobile agent based network management methods have been studied to solve and overcome these problem. However, in these mobile agent based methods, as the number of nodes to be managed is increased, the mobile data are increased accumulatively and the effectiveness of the network management is decreased. In this paper, we propose the split management method by using mobile agents to handle these problems. In our method, the nodes are divided into groups to be handled by separate mobile agents. Each mobile agent visits its own nodes and gets management information from them. We demonstrate the effectiveness of our proposed method using experimental results.

• The KIPS Transactions:PartC
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• v.12C no.5 s.101
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• pp.679-686
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• 2005

Because EPON access network shares a medium and aggregates the traffic from EPON subscribers, scheduling media access control on EPON bandwidth allocation is very important. Furthermore DBA mechanism of EPON based on TDMA is out of specification and up to implementation. This paper deals with a DBA method to guarantee the QoS of the delay sensitive traffic on the base of best-effort service and delay priority queue management. The proposed method performs virtual scheduling algorithm for the integrated traffic. It uses the same MAC messages and tries to guarantee the QoS of higher priority traffic first with a simple DBA architecture. We evaluate the algorithm for traffic delay according to polling interval and traffic load of upstream and downstream. The results show that the proposed method can guarantee the QoS of the delay sensitive traffic with priority of the service classes.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.1
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• pp.1-8
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• 2006

A modified PCF(Point Coordination Function) protocol with the optimal polling sequence is defined in detail and shown to improve the efficiency of the conventional PCF protocol in IEEE 802.11 wireless LAN standard. The problem for the optimal polling sequence is formulated as TSP(Travelling Salesman Problem) with the distance values of 1's or 0's. Numerical examples show that the optimal polling sequence increases the capacity of the real-time service such as VoIP(Voice over Internet Protocol).

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.2
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• pp.237-245
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• 2007

In this paper, a modified PCF (Point Coordination Function) MAC (Medium Access Control) Protocol is proposed to support the multiple direct link communication between STAs (STAtions) in infrastructure mode IEEE 802.11 wireless LANs. By the proposed MAC protocol, the direct link communication between STAs, which are located within the communication range of each other, is allowed without the use of AP (Access Point) as a relay. Moreover, when multiple direct data communication between STAs can be simultaneously performed with a sufficiently small interference, multiple simultaneous direct link communication is allowed for the efficient use of radio bandwidth. AP polls STAs to grant the transmission opportunities using the direct link communication by transmitting the polling frames to STAs. An efficient polling method for granting the transmission opportunities to STAs is proposed to reduce the number of the polling frame transmissions and enhance the PCF MAC performance.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1104-1107
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• 2010

홍채 인식 시스템의 응용 프레임워크는 홍채 인식기 모듈을 컴퓨터에 연결할 때 사용되는 USB 호스트 콘트롤러 드라이버와 응용 프로그램 사이에서 둘을 제어하는 스탠다드 라이브러리를 제공한다. 본 논문에서는 스탠다드 라이브러리 설계와 구현을 설명하고 있다. 스탠다드 라이브러리는 표준 호출규약을 지키므로 응용 프로그램은 다양한 언어로 작성할 수 있다. 또한, 기존의 폴링 방식으로 구현된 스탠다드 라이브러리를 콜백을 이용하여 구현함으로써 네트워크를 통해 많은 사람들이 동시에 홍채 인식기를 사용할 때 리소스 사용을 경감할 수 있는 장점이 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.1013-1016
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• 2011

최근 정보통신 기술의 발전과 더불어 가정 내에서의 홈 네트워크 서비스에 많은 관심이 집중되고 있다. 기존 홈 네트워크 서비스는 유선으로 연결되어야 함으로 신축 현장에만 적용이 가능했으나 무선으로 연결하는 경우 기 구축되어 있는 현장에도 별도의 배선공사 없이 홈 네트워크 서비스를 제공할 수 있다는 장점이 있다. 본 논문에서는 UHF 대역을 이용한 무선 홈 네트워크 시스템을 설계하였다. 시스템 구성 요소로는 HN(Home Network)세대기, 무선통신모듈, 무선제어기 등이 있다. 세대기와 무선통신 모듈 사이의 통신에는 폴링 방식을 사용하여 신뢰성을 높였으며 그에 적합한 프로토콜을 설계하였다.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.3
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• pp.69-75
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• 2011

In this paper, we propose an anycast event driven synchronization mechanism to reduce power overheads. Our proposed mechanism can reduce unnecessary polling operations on SHI(Snoop Hit Invalidate) or SHR(Snoop Hit Read) states. It prevents waisting bandwidth and reduces power overheads on polling operation. Also it decreases transition power of state change compared to broadcast model. Simulation results indicated that the proposed architecture had about 15.3% of power decrease compared to spin-lock model and about 4.7% of power decrease compared to broadcast model. Overall results indicated that proposed synchronization mechanism could increase power efficiency of multi-core system by reducing power overheads.