• Journal of Korean Society of Transportation
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• v.21 no.5
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• pp.119-133
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• 2003

도로는 교통기능 외에 여러 시설물을 수용할 수 있는 사회 인프라구축의 공간으로 활용될 수 있기 때문에 서울시뿐만 아니라 각 지방자치단체에서는 이러한 공간을 활용하기 위한 도로점용공사는 매년 전국적으로 수만 건에 달하고 있다. 따라서. 매년 발생하는 도로점용공사의 차로과다 점용, 교통시설물 설치 부적절, 보행자 안전무시, 공사안내표지 부적절, 공사구간에서의 불법 주.정차 등의 문제점이 계속하여 발생.지적되고 있으나 이에 따른 관련 규정이 미흡하여 도로점용공사 시행자의 불법을 초래하고 있는 실정이다. 또한 서울시의 경우 시스템적 접근방법인 관련조례에 의해서 수행되기보다는, 교통자문회의로 운영되고 있으며, 관련 인원 및 법적 제재조치가 미약하여 도로점용공사의 효과적인 관리가 어려운 실정이다. 따라서 서울시 및 각 지방자치단체에서는 도로점용공사로 인한 보행자와 운전자의 통행권 확보와 안전상의 문제 등을 하루빨리 인식하여 도로점용공사에 따른 도로공사장 교통관리 규정을 법규화 하여 체계적으로 관리할 필요가 있다. 이에 따라, 본 논문에서는 도로점용공사에 따른 관련법 및 적용대상, 관련보고서 검토, 서울시를 사례로 한 공사중 교통처리방안 운영실태 및 문제점의 진단을 통하여 향후 도로공사장 교통관리 규정의 운영적 및 제도적 측면의 개선방안과 향후 추진방향을 제시하고자 한다.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.322-326
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• 2009

본 연구는 지열원식 냉난방 히트펌프 시스템의 상태를 실시간으로 감시하고 열 성능을 실시간으로 평가할 수 있도록 한 지열원식 냉난방 히트펌프 시스템의 상태 감시 및 열 성능 평가 방법에 관한 것으로서, 이러한 본 연구는, 프로그램 실행을 통하여 측정 간격이 설정되고, 다이얼로그 박스 상에서 시스템 개요, 공사개요, 히트펌프설비개요, 지열루핑 설비개요, 버퍼탱크, 건물개요 등을 입력받은 후 시스템의 개통도 이미지 파일프로그램 로딩과 각종 계측기를 통해 전기적인 데이터의 취득 기능 등의 데이터측정 준비를 위한 기본 제1단계와; 취득된 전기적인 데이터를 물리 신호로 변환한 후 기본 데이터 산정하고 결과를 도시하는 "시스템 실시간 작동 상태 감시" 기능의 제2단계와; 기본 순간치 데이터를 근거로 "시스템의 열성능 평가 변수 값 산정과 결과"를 도시하는 제3단계와; 2단계에서의 기본 데이터와 3단계에서의 열성능 평가 변수 값을 후처리용 데이터 파일로 저장하는 제4단계와; 현장에 설치된 지열원식 히트펌프 시스템의 상태를 TCP/IP 프로토콜을 활용하여 원격지(본사)에서 IP 접속을 통하여 원거리 원격 작동상태 감시 기능 및 제어를 수행하는 제5단계를 수행하게 된다.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2006.06a
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• pp.105-108
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• 2006

무선인지(RFID)시스템은 많은 산업 분야에 적용되고 있다. 대표적인 예로써 RFID 시스템을 이용한 출입 관제시스템을 들 수 있으며, 이런 경우 기존의 건물에 이 시스템을 설치하려고 하면 출입문을 개조하여야 한다. 하지만 무선 통신을 이용하면, 리더기에서 호스트 컴퓨터로의 접근이 용이해지므로 출입문 개조에 있어서도 한결 수월해진다. 이 때 필요한 것이 무선 디지털 데이터 통신 기술과 원격지에서 Tag의 ID를 모니터링을 위한 TCP/IP를 이용한 Ethernet 통신이다. 본 논문에서는 이러한 시스템의 개발방법에 대해 설명하였으며 RFID 리더기는 125KHz를 사용 주파수로 하고, Tag 칩은 Microchip사의 MCRF 250을 사용하였다. 그리고 무선 데이터 통신을 위해서 CC1020칩을 사용하였으며 이 칩의 장점은 간단히 레지스터를 설정으로 송신 상태 혹은 수신 상태로 변환이 가능하고 또한 주파수 설정도 가능하다는 것이다. 마지막으로 Ethernet 통신을 위해서는 W3100A칩을 이용하였으며, Ethernet 통신에 있어 OS가 차지하는 부분으로 하드웨어를 통해 구현하였다. 실험을 위해 하드웨어를 구성하고 각 모듈별 동작을 분석하고. 각 부분의 파형을 확인하였다. DB에 해당하는 Application을 통해 Tag ID DATA를 확인하였다.

• The Transactions of the Korea Information Processing Society
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• v.5 no.3
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• pp.763-773
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• 1998

본논문은 TCP/IP를 사용하는 기존의 LAN상에 이동 호스트들이 셀의 형태로 덧붙여진 환경에서 이동 호스트와 고정 호스트간의 지속적인 세션을 지원하는 개선된 IP 체계인 SIMIP을 제안하였다. 이동형 프로토콜 설계시 라우팅 최적화가 매우 중요한 항목이고 이는 이동 호스트의 위치정보 관리방법과 직접적인 관계가 있다. 기존의 아이비엠과 마쓰시다 제안은 이를 집중화하였으며 콜롬비아와 소니제안은 이를 분산화하였다. MH 위치정보를 집중화하면 트라이앵글 문제로 인해 최적의 라우팅 경로를 지원할 수 없으며 집중화된 라우터의 실패 발생시는 위험도가 매우 크다. 반면에 분산화하면 위의 문제들은 해결되지만 캡슐화되는 주소를 찾기위해 CACH 또는 AMT와 같은 복잡한 기법이 요구된다. SIMIP은 MH위치정보를 DMR에 집중화하였으나 DMR 실패 발생시는 복수의 GMR중에서 하나가 자동적으로 DMR로 대체되어 위험도를 최소화시켰고, 'DMR 경로변경'에 의해 최적의 라우팅 경로를 지원하였다는 점에서 다른 제안들과 차이가 있다. 이동에 따른 주소변경을 해결하기 위해 가상네트워크 기법을 적용하였고, 이동 호스트로의 데이터 송신시 디폴트 라우팅 개념을 이용하였고, 이동라우터간 터널링에 IPIP 캡슐화를 사용하였다. SIMIP은 다른 제안에 비해 실용성있고, 신뢰성이 강하며, 구현이 용이하므로 산업계에서 활용가치가 있으리라본다.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.91-102
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• 2009

The average window size is most closely related to average throughput. In order to improve fairness, the proposed dropper tries to control the window size of each flow to equal level by intentional packet drop. Intentional packet drop is performed only to the flows that have been occupied bandwidth in a large amount. Because of intentional packet drop, this flow cut down its transmission rate to a half. Accordingly, somewhat capacity of core link comes into existence. And other flow can use this new capacity of this link. Hence other flows have more throughput than before. In this paper, we propose the TRC (Transmission Rate Control) Dropper improving the fairness between individual flows of aggregated sources on DiffServ network. It has the fairness improvement mechanism mentioned above paragraph.

• Journal of Mechanical Science and Technology
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• v.20 no.4
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• pp.455-466
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• 2006

This study was an attempt to control and monitor Computerized Numerical Controller (CNC) machines anywhere and anytime for the development of a ubiquitous machine (u-machine). With a Personal Digital Assistant (PDA) phone, the machine status and machining data of CNC machines can be monitored in wired and wireless environments, including the environments of IMT2000 and Wireless LAN. Moreover, CNC machines can be controlled anywhere and anytime. The concept of the anywhere-anytime controlling and monitoring of a manufacturing system was implemented in this study for the purpose of u-manufacturing and u-machines. In this concept, the communication between the CNC controller and the PDA phone was successfully performed anywhere and anytime for the real-time monitoring and control of CNC machines. In addition, the interface between the CNC controller and the developed application module was implemented by Object linking and embedding for Process Control (OPC) and shared CNC memory. For communication, the design of a server contents module within the target CNC was based on a TCP/IP. Furthermore, the client contents module within the PDA phone was designed with the aid of embedded c++ programming for mobile communication. For the interface, the monitoring data, such as the machine status, the machine running state, the name of the Numerical Control (NC) program, the alarm and the position of the stage axes, were acquired in real time from real machines with the aid of the OPC method and by sharing the CNC memory. The control data, such as the start, hold, emergency stop, reserved start and reserved stop, were also applied to the CNC domain of the real machine. CNC machines can therefore be controlled and monitored in real time, anywhere and anytime. Moreover, prompt notification from CNC machines to mobile phones, including cellular phones and PDA phones, can be automatically realized in emergencies.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.334-334
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• 2022

Improvement of old-fashioned rain gauge systems for automatic, timely, continuous, and accurate precipitation observation is highly essential for weather/climate prediction and natural hazards early warning, since the occurrence frequency and intensity of heavy and extreme precipitation events (especially floods) are recently getting more increase and severe worldwide due to climate change. Although rain gauge accuracy of 0.1 mm is recommended by the World Meteorological Organization (WMO), the traditional rain gauges in both weighting and tipping bucket types are often unable to meet that demand due to several existing technical limitations together with higher production and maintenance costs. Therefore, we aim to introduce a newly developed and cost-effective hybrid rain gauge system at 0.1 mm accuracy that combines advantages of weighting and tipping bucket types for continuous, automatic, and accurate precipitation observation, where the errors from long-term load cells and external environmental sources (e.g., winds) can be removed via an automatic drainage system and artificial intelligence-based data quality control procedure. Our rain gauge system consists of an instrument unit for measuring precipitation, a communication unit for transmitting and receiving measured precipitation signals, and a database unit for storing, processing, and analyzing precipitation data. This newly developed rain gauge was designed according to the weather instrument criteria, where precipitation amounts filled into the tipping bucket are measured considering the receiver's diameter, the maximum measurement of precipitation, drainage time, and the conductivity marking. Moreover, it is also designed to transmit the measured precipitation data stored in the PCB through RS232, RS485, and TCP/IP, together with connecting to the data logger to enable data collection and analysis based on user needs. Preliminary results from a comparison with an existing 1.0-mm tipping bucket rain gauge indicated that our developed rain gauge has an excellent performance in continuous precipitation observation with higher measurement accuracy, more correct precipitation days observed (120 days), and a lower error of roughly 27 mm occurred during the measurement period.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1705-1711
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• 1991

On-line fault detection and diagnosis has an increasing interest in a chemical process industry, especially for a process control and automation. The chemical process needs an intelligent operation-aided workstation which can do such tasks as process monitoring, fault detection, fault diagnosis and action guidance in semiautomatic mode. These tasks can increase the performance of a process operation and give merits in economics, safety and reliability. Aiming these tasks, series of researches have been done in our lab. Main results from these researches are building appropriate knowledge representation models and a diagnosis mechanism for fault detection and diagnosis in a chemical process. The knowledge representation schemes developed in our previous research, the symptom tree model and the fault-consequence digraph, showed the effectiveness and the usefulness in a real-time application, of the process diagnosis, especially in large and complex plants. However in our previous approach, the diagnosis speed is its demerit in spite of its merits of high resolution, mainly due to using two knowledge models complementarily. In our current study, new knowledge representation scheme is developed which integrates the previous two knowledge models, the symptom tree and the fault-consequence digraph, into one. This new model is constructed using a material balance, energy balance, momentum balance and equipment constraints. Controller related constraints are included in this new model, which possesses merits of the two previous models. This new integrated model will be tested and verified by the real-time application in a BTX process or a crude unit process. The reliability and flexibility will be greatly enhanced compared to the previous model in spite of the low diagnosis speed. Nexpert Object for the expert system shell and SUN4 workstation for the hardware platform are used. TCP/IP for a communication protocol and interfacing to a dynamic simulator, SPEEDUP, for a dynamic data generation are being studied.

• Journal of Periodontal and Implant Science
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• v.38 no.sup2
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• pp.273-298
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• 2008

Purpose: The aim of this review is to introduce a novel bone-graft material for hard-tissue regeneration based on the calcium phosphate glass(CPG). Materials and Methods: CPG was synthesized by melting and subsequent quenching process in the system of CaO-$CaF_2-P_2O_5$-MgO-ZnO having a much lower Ca/P ratio than that of conventional calcium phosphates such as HA or TCP. The biodegradability and bioactivity were performed. Effects on the proliferation, calcification and mineralization of osteoblast-like cells were examined in vitro. Influence in new bone and cementum formations was investigated in vivo using calvarial defects of Sprague-Dawley rats as well as 1-wall intrabony defect of beagle dogs. The application to the tissue-engineered macroporous scaffold and in vitro and in vivo tests was explored. Results: The extent of dissolution decreased with increasing Ca/P ratio. Exposure to either simulated body fluid or fetal bovine serum caused precipitation on the surface. The calcification and mineralization of osteoblast-like cells were enhanced by CPG. CPG promoted new bone and cementum formation in the calvarial defect of Sprague-Dawley rats after 8 weeks. The macroporous scaffolds can be fabricated with $500{\sim}800{\mu}m$ of pore size and a three-dimensionally interconnected open pore system. The stem cells were seeded continuously proliferated in CPG scaffold. Extracellular matrix and the osteocalcin were observed at the $2^{nd}$ days and $4^{th}$ week. A significant difference in new bone and cementum formations was observed in vivo (p<0.05). Conclusion: The novel calcium phosphate glass may play an integral role as potential biomaterial for regeneration of new bone and cementum.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.107-107
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• 2019

Millets are provided considerable amounts of nutrients and gluten-free cereal products and their rich non-nutritional compounds having proven health benefits, especially phenolic compounds. The aim of present investigation was to determine phenolic composition and antioxidant and SOD activity of three different millet of genetic resources namely, foxtail, proso and finger millet. Phenolic compounds were extracted from dehulled grain of genetic resources using methanol and examined for their total phenolic content (TPC), antioxidant activities and superoxide dismutase (SOD)-like activity. The TPC range of hog millet, finger millet and finger millet range from 3.3 to 25.1, 11.1 to 29.0 and 3.8 to 94.3 gallic acid equivalent (GAE)mg/g, respectively. Most of TCP content in dehulled millet grains was distributed from 10 to 20 gallic acid equivalent (GAE)/g, but two accessions of finger millet (IT235690 and 235689) were showed over than 90. The antioxidant activities were measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Finger millet and hog millet showed 26.4% and 26.7% in the mean of DPPH scavenging activity percentage, but foxtail millet was 13%. The finger millet showed the higher value than hog and foxtail millet in superoxide dismutase (SOD)-like activity. Particularly, two accessions of finger millet (IT235690 and 235689) showed the highest phenolic content and antioxidant activities among the used millet genetic resources and will be primary resources for finger millet breeding to develop the appropriate breeding strategies.