• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.4
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• pp.326-333
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• 2004

This research proposes a high frequency resonant inverter for high power conversion apparatus, which is consist of two L-C linked full-bridge inverter using MOSFET in order to distribute voltage and current of the devices. As an output power control strategy, the time sharing control method is applied. From the computer simulation results, the inverters and devices can be shared properly voltage and current rating of the system. And also, theoretical characteristics of the proposed circuit are compared with experimental results.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.419-423
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• 2002

본 연구는 농업기계에 관한 정보를 종합적으로 체계화하여 데이터베이스로 구축하고 정보 수요자가 인터넷을 통해 구축된 데이터베이스를 쉽게 검색할 수 있는 프로그램을 개발하기 위 해 수행되었다. 가. 농업기계 정보 DB는 농업기계와 관련된 텍스트, 이미지, 수치자료들을 데이터베이스화한 것으로서 지원시책, 구입, 이용, 사후관리, 연구 및 교육, 시험평가, 통계, 기타 정보 등의 8개의 카테고리로 구성하였으며 원시자료가 텍스트, 이미지 자료인 경우는 Html로 자체 제작하거나 기존 사이트에 링크하고, 원시자료가 수치자료인 농업기계 사양 및 농업기계화 현황은 관계형 데이터베이스로 구축하였다. 나. 구축된 농업기계 정보 DB를 검색하기 위하여 검색프로그램을 개발하였다. Html로 제작된 DB는 메뉴식 검색방법 또는 검색어 검색방법으로 검색할 수 있으며 관계형 DB는 DBMS를 개발하여 검색이 가능하도록 하였다.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.9
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• pp.503-513
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• 2002

Since CC-NUMA architecture has to access remote memory, the interconnection network determines the performance of the CC-NUMA system. Bus which has been used as a popular interconnection network has many limits in a large-scale system because of the limited physical scalability and bandwidth. The dual ring interconnection network, composed of high-speed point-to-point links, is made to resolve the defects of the bus for the large-scale system. However, it also has a problem, in that the response latency is rapidly increased when many nodes are attached to the snooping based CC-NUMA system with the dual ring. In this paper, we propose a ring architecture with repeater nodes in order to overcome the problem of the dual ring on a snooping based CC-NUMA system, and design a repeater node adapted to this architecture. We will also analyze the effects of proposed architecture on the system performance and the response latency by using a probability-driven simulator.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.2
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• pp.34-44
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• 2007

Many urban cities deployed ITS technologies to improve the efficiency of traffic operation and management including a real-time franc control system (i.e., COSMOS). The system adopted loop detector system to collect traffic information such as volume, occupancy time, degree of saturation, and queue length. This paper investigated the applicability of detector information within COSMOS to represent the congestion level of the links. Initially, link travel times obtained from the field study were related with each of detector information. Results showed that queue length was highly correlated with link travel time, and direct link travel time estimation using the spot speed data produced high estimation error rates. From this analysis, a procedure was proposed to estimate congestion level of the links using both degree of saturation and queue length information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.147-151
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• 2002

One of the main issues in Diffserv AS architecture is guaranteeing fairness among the flows which have their own QoS requirements. Because the methodology of resource allocation and traffic conditioning would affect the end-to-end QoS and backbone link utilization. In this paper, we propose a variant of TSW algorithm for enhancing fair bandwidth allocation and link utilization and presents performance evaluation between TSW & TS2W3C through NS-2 Simulations.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.5
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• pp.21-26
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• 2020

A descending lifeline is the only self-escape fire apparatus for fire in high-rise buildings and is installed in most buildings according to fire-fighting law. However, it is difficult to properly use and quickly evacuate during an emergency due to its complex installation methods and procedures, even if users are pre-educated. In this paper, a new one-touch descending lifeline, which simplifies usage procedures and can be used regardless of whether users are educated, is proposed to solve the drawbacks of the conventional descending lifeline. All separate parts that require additional installation are initially assembled in a box, and the concept of a double square linkage is proposed to enable escape in a single motion of pushing the handle attached to the box. Three steps of kinematic design are explored to determine an appropriate configuration of double square linkage, and its dimensions are determined using Matlab and NX CAD software. The proposed all-in-one descending lifeline also follows the enforcement decree of the Fire Control Act, and its feasibility is verified through fabrication.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.430-436
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• 2019

It is needed to develop an antenna with features of subminiature, light weight and multi-band operation for the variaty services in maritime and industrial fields. The PCB pattern antenna is one of the appropreiate antennas solving these requirements. In this research, the design and fabrication of the PCB pattern antenna operating on the single band of 920 MHz are investigated. The final goal is that the development of the dual band PCB pattern antenna operating on 260 MHz and 920 MHz, which is based on the proposed antenna. It is evident that the performance in the frequencies of 902 MHz, 915 MHz and 928 MHz among of 920 MHz ISM band is better than that in other frequencies. It is also confirmed that the differences of the voltage standing wave ratio, return loss, gain and efficiency between three frequencies are less than 5%. It is expected that the development of communication link of 5-10 km is possible when the induced results are applied into the low power wide area (LPWA) network desinged by the rule of -30 dB sensitivity.

• Journal of Advanced Navigation Technology
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• v.21 no.4
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• pp.413-421
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• 2017

In this paper, we designed and fabricated a compact UHF receive module for efficient operation such as tactical and operation situation, target location information confirmation, target reset using Link-K(Korean joint tactical data link system). And the effect of target reset was analyzed by simulation. The designed module consists of UHF(ultra high frequency) receiver section, control section, and power distribution section. The UHF receiver section performs frequency down conversion, filtering and automatic gain control, etc. The control section demodulates frequency down-converted signals, extracts information, and performs external interworking. The power distribution section supplies external power, generates and supplies the power required by each section. The fabricated module was dimension of $105{\times}105{\times}80mm$ and weighed 1.10 kg and The receiving distance is more than 50 km.