• Wind and Structures
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• v.20 no.6
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• pp.793-810
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• 2015

Tests were conducted at the Florida International University (FIU) Wall of Wind (WOW) to investigate the susceptibility of Variable Message Signs (VMS) to wind induced vibrations due to vortex shedding and galloping instability. Large scale VMS models were tested in turbulence representative of the high frequency end of the spectrum in a simulated suburban atmospheric boundary layer. Data was measured for the $0^{\circ}$ and $45^{\circ}$ horizontal wind approach directions and vertical attack angles ranging from $-4.5^{\circ}$ to $+4.5^{\circ}$. Analysis of the power spectrum of the fluctuating lift indicated that vertical vortex oscillations could be significant for VMS with a large depth ratio attached to a structure with a low natural frequency. Analysis of the galloping test data indicated that VMS with large depth ratios, greater than about 0.5, and low natural frequency could also be subject to galloping instability.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.50-52
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• 2001

반도체 장비간 통신의 표준인 SECS(SEMI Equipment Communication Standard)는 반도체 제조 업체에서 많이 사용되고 있다. SECS-I의 단점을 보완하기 위해 제안된 HSMS (High-speed SECS Message Services)는, TCP/IP를 지원하고 SECS-I에 비해 통신 속도가 높다. 사용자는 HSMS를 이용하여 LAN을 통한 장비 제어 및 모니터링이 가능하게 되었다. 그러나, 네트워크의 확장에 대한 관심 고조로 기존의 제한된 영역의 네트워크 구성에 대한 변화가 필요하게 되었다. 또한 사용자가 항상 LAN의 범위 내에서 장비 모니터링 및 제어하기에는 위치적 제약이 많다. 그렇지만 HSMS는 Web을 통한 데이터 전송 요구를 수용하지 못하고 있다. 따라서 SECS-II message가 Web을 통해 전송될 수 있는 새로운 포맷이 필요하다. 본 논문에서는, 구조화된 데이터를 정의하기 유리한 마크업 언어인 XML을 이용하여, SECS-II message를 Web으로 전송할 수 있는 포맷을 정의하고 이를 구현한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.856-862
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• 2002

The object-oriented(00) distributed real-time(RT) programming movement started in1990's and is growing rapidly at this turn of the century. Distributed real-time simulation is a field in its infancy but it is bounded to receive steadily growing recognition for its importance and wide applicability. The scheme is called the distributed time-triggered simulation scheme which is conceptually simple and easy to use but widely applicable. A new generation object oriented(00) RT programming scheme is called the time-triggered message triggered object(TMO)programming scheme and it is used to make specific illustrations of the issues. The TMO structuring scheme is a general-style components structuring scheme and supports design of all types of component including hard real time objects and non real time objects within one general structure.

• Journal of information and communication convergence engineering
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• v.19 no.1
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• pp.16-21
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• 2021

In this paper, to prevent accidents of school vehicles used by students, which have emerged as a continuous social problem, a boarding and leaving notification system using Bluetooth beacons is proposed. The platform structure uses Bluetooth, a smartphone, and an application, and provides real-time message reception between parents and teachers. It is not simply a system with Bluetooth capability alone, but also an IcT technology that is closely related to real life using two-way communication. The purpose is to provide user-friendly ICT technology as an integrated system for more practical effects. Two-way exchange of information between parents and teachers using cloud servers is made possible. By using this Bluetooth beacon notification system, safety accidents in student vehicles are reduced, which brings confidence from traffic accidents to schoolchildren of parents and teachers. Therefore, it is expected that parents and teachers are expected to improve their mental stability and quality of life from traffic accidents.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.771-774
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• 1999

This paper presents a new timing structure for real time communications and its performance analysis. The cycle time consists of several "one time slot" which may be an interval defined by a synchronous traffic part followed by an asynchronous traffic part. If a station receives a token within a synchronous interval, it transmits its synchronous message if any, otherwise it may transmit an asynchronous message. This scheme is different from usual allocation schemes which divide one cycle into alternating synchronous and asynchronous subslots. This protocol is designed to prevent low priority messages from delaying too much due to lots of high priority messages. We propose the algorithm and show its justification by simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.821-831
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• 2006

In this paper we researched on the development methods and design of the B-ISDN protocol embedded Internet-Phone PBX System for the previous telephone exchange and communication. We designed the structure of the user terminal md exchange server of the Internet-Phone PBX System, defined message and data structure for call control, and designed call control message flows between sender and receiver terminal for user's communication.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1296-1304
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• 2007

In this paper we researched on the implementation of the B-ISDN protocol embedded IP-PBX System with the computers interconnected by the Internet for the telephone exchange and multimedia communication. For the improvement on the structural problems of the previous PABX we designed the structure of the IP-PBX System, defined message and data structure for call control, designed call control state transition, and implemented call control message flows for user's communication.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.12
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• pp.2256-2264
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• 2007

In this paper we researched on the implementation of the B-ISDN protocol embedded IP-PBX System with the computers interconnected by the Internet for the telephone exchange and multimedia communication. For the improvement on the structural problems of the previous PABX we designed the structure of the IP-PBX System, defined message and data structure for call control, designed call control state transition and implemented call control message flows for user's communication.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.4
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• pp.247-253
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• 2008

The TMO may contain two types of methods, time-triggered methods(also called the spontaneous methods of SpMs) which are clearly separated from the conventional service methods (SvMs). The SpM executions are triggered upon design time whereas the SvM executions are triggered by service request message from clients. In this paper, we describes the application environment as the patient monitor telemedicine system with TMO structure. Vital sign information web viewer systems is also the standard protocol for medical image and transfer. In order to embrace new technologies as telemedicine service, it is important to develope the standard protocol between different systems in the hospital, as well as the communication with external hospital systems.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.289-440
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• 1998

This paper describes an interconnection network structure which transports information among processors through a high speed ATM switch. To efficiently use the high speed ATM switch for the message-based multiprocessor, we implemented the cell router that performs multiplexing and demultiplexing of cells from/to processors. In this system, we use the expanded internal cell format including 3bytes for switch routing information. This interconnection network has 3 stage routing strategies: ATM switch routing using switch routing information, cell router routing using a virtual path identifier (VPI) and cell reassembly routing using a virtual channel indentifier (VCI). The interconnection network consists of the NxN folded switch and N cell routers with the M processor interface. Therefore, the maximum number of NxM processors can be interconnected for message communication. This interconnection network using the ATM switch makes a significant improvement in terms of message passing latency and scalability. Additionally, we evaluated the transmission overhead in this interconnection network using ATM switch.