• 한국정보통신학회논문지
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• 제14권7호
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• pp.1641-1646
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• 2010

최근 들어 환경에 대한 관심이 높아지면서 대기오염 방지에 비중을 둔 CNG 연료에 대한 연구가 활발하다. 그러나, 가솔린연료에 비해 출력이 감소하며, 1회 충전 거리가 짧은 단점을 가지고 있다. 특히, 토크 및 출력 저하의 원인으로는 CNG 연료가 가솔린에 비해 단위체적당 발열량이 낮고, 화염 전파 속도가 느림에 따라 혼합기가 연소되는 타이밍 손실 등에 기인한다. 본 연구에서는 타이밍 손실을 고려한 점화 진각 제어장치를 설계하여 이를 차량에 실제 장착하고, 새시 다이나모미터(Chassis Dynamometer)에서 엔진 출력 및 토크를 측정하였다. 측정된 결과 일반적인 CNG 바이 퓨얼 시스템에 비하여 최대 토크 및 출력이 향상되었다.

• 산업경영시스템학회지
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• 제34권3호
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• pp.123-133
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• 2011

The advanced planning and scheduling(APS) is an well known enterprise information system that provides optimal production schedules and supports to complete production on time by solving the complex scheduling problems including capacity and due dates. In this paper, we focused on the improvement of the APS that is already established on a real company. The existing APS had several drawbacks, thus utilization and satisfaction were very low. We performed the focused group interviews and the process analysis and could find that the end users and developers have various objectives and the frequently used functions are different. We applied the analytical hierarchy process(AHP) to converge opinions of them on quantitative data. The results show that it is necessary to enhance visibility, to improve user interfaces and response speed, and to reconcile the real business process and the APS's process.

• 산업공학
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• 제9권3호
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• pp.306-316
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• 1996

The easily use of WWW and Web browser of INTERNET makes the world our stage. But when we search for the information and resource that we want, the information supplied by search engine (e.g., Yahoo, Lycos, WebCrawler, Alta Vista) is inadequate to acquire the necessary and related information of research issues. This paper surveys AMT(Advanced Manufacturing Technology) which is the research topics recently on the WWW(WorLd Wide Web) and provides searching methods and information for academic research, technical report, proceedings, software, etc. It also briefly surveys WWW-VL(Virtual Library) and reviews the major three technology, CALS (Commerce At Light Speed), AMS(Agile Manufacturing System), CE(Concurrent Engineering), that is recently the focus of the research issue of Industrial Engineer.

• KIEAE Journal
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• 제12권3호
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• pp.77-82
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• 2012

With developments of architectural and information technologies at the knowledge-information oriented society in the 21st century, there are the needs on intelligent buildings equipped with advanced systems to integrate both technologies. The intelligent building means a smart building which provides comfortable environments, realizes fast and speed information and telecommunication network services, and maximizes work productivities by adopting various systems suitable to uses, sizes, and functions of buildings. In order to meet these needs of the times, the domestic intelligent building certification system has been enforced in 2006. Recently, the intelligent building certification system was newly revised for revitalizing the spread of intelligent buildings. Thus, this paper investigates rating criteria and assessment standards of the new certification system focused on office building projects and suggests strategies for obtaining certifications by analyzing cases which were certified on the previous version of the system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권11호
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• pp.5276-5298
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• 2019

Internet of Things (IoT) based sensor networks have gained unprecedented popularity in recent years. With the exponential explosion of the objects (sensors and mobiles), the bandwidth and the speed of data transmission are dwarfed by the anticipated emergence of IoT. In this paper, we propose a novel heterogeneous IoT model integrated the power line communication (PLC) and WiFi network to increase the network capacity and cope with the rapid growth of the objects. We firstly propose the mean transmission delay calculation algorithm based the 3D Markov chain according to the multi-priority of the objects. Then, the attractor selection algorithm, which is based on the adaptive behavior of the biological system, is exploited. The combined the 3D Markov chain and the attractor selection model, named MASM, can select the optimal path adaptively in the heterogeneous IoT according to the environment. Furthermore, we verify that the MASM improves the transmission efficiency and reduce the transmission delay effectively. The simulation results show that the MASM is stable to changes in the environment and more applicable for the heterogeneous IoT, compared with the other algorithms.

• International journal of advanced smart convergence
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• 제3권2호
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• pp.14-17
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• 2014

Precision agriculture relies on information technology, whose precondition is providing real-time and accurate information. It depends on various kinds of advanced sensors, such as environmental temperature and humidity, wind speed, light intensity, and other types of sensors. Currently, it is a hot topic how to collect accurate information, the main raw data for agricultural experts, monitored by these sensors timely. Most existing work in WSNs addresses their fundamental challenges, including power supply, limited memory, processing power and communication bandwidth and focuses entirely on their operating system and networking protocol design and implementation. However, it is not easy to find the self-localization capability of wireless sensor networks. Because of constraints on the cost and size of sensors, energy consumption, implementation environment and the deployment of sensors, most sensors do not know their locations. This paper provides maximum likelihood estimators for sensor location estimation when observations are time-of arrival (TOA) range measurement.

• Nuclear Engineering and Technology
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• 제50권4호
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• pp.553-561
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• 2018

To easily understand and systematically express the behaviors of the industrial systems, various system modeling techniques have been developed. Particularly, the importance of system modeling has been greatly emphasized in recent years since modern industrial systems have become larger and more complex. Multilevel flow modeling (MFM) is one of the qualitative modeling techniques, applied for the representation and reasoning of target system characteristics and phenomena. MFM can be applied to industrial systems without additional domain-specific assumptions or detailed knowledge, and qualitative reasoning regarding event causes and consequences can be conducted with high speed and fidelity. However, current MFM techniques have a limitation, i.e., the dynamic features of a target system are not considered because time-related concepts are not involved. The applicability of MFM has been restricted since time-related information is essential for the modeling of dynamic systems. Specifically, the results from the reasoning processes include relatively less information because they did not utilize time-related data. In this article, the concepts of time-to-detect and time-to-effect were adopted from the system failure model to incorporate time-related issues into MFM, and a methodology for enhancing MFM-based reasoning with time-series data was suggested.

• 한국컴퓨터정보학회논문지
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• 제5권2호
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• pp.81-89
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• 2000

본 논문에서는 효율적이며 편리한 원격의료시스템을 개발하기 위해 분산 멀티미디어 기술을 바탕으로 256kbps 전용선과 10Mbps Ethernet LAN망을 기반으로 원격의료시스템을 설계 및 구현하였다. 원격 의료시스템은 분산멀티미디어 기술을 이용하여 여러 개의 영상획득장치와 저장 장치 및 서버들을 네트워크와 효율적으로 연결함으로써 통한 환경아래 빠르고 간편하게 의료영상을 열람하고 저장, 전송할 수 있게 하였다. 의료영상의 전송 효율을 높이고 추후 Web의로의 확장을 위해서 JPEG방식의 영상압축을 실시하였으며 데이터베이스의 안정성과 효율을 높이기 위해 의료정보를 데이터베이스로 의료영상을 파일로 데이터베이스로 구축하여 관리할 수 있게 설계와 구현을 하였다.

• 한국항행학회논문지
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• 제18권1호
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• pp.14-21
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• 2014

본 논문에서는 주행상황의 자동차 정보를 인식하기 위하여 차량, 운전자, 환경 정보와 함께 주행상태 정보, 운전자상태 정보를 추가하여 실시간으로 바뀌는 운전행동에 대한 정보를 상황인식에 활용하여 운전자의 의도를 반영할 수 있도록 하였으며, 온톨로지 기반 상황인식 모델을 구성하여 다양한 상황에서의 상황인식이 가능하게 설계하였다. 상황정보의 획득방법으로 운전자 정보와 주행정보는 카메라를 이용한 영상인식 기술을 활용하며, 자동차 정보는 OBD-II 프로토콜을 이용한 정보 획득 장치를 이용한다. 실험결과 운전자 상태정보와 주행정보의 분석을 통하여 운전자 의도를 반영한 제안 시스템이 고속주행 상황에서의 차선이탈 경고 서비스 및 저속주행 상황에서의 안전거리 경보서비스를 위한 상황인식에 있어서 기존의 차량, 운전자, 환경정보를 활용한 방식보다 운전자 안전지원 서비스에 우수한 성능을 확인할 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.182-185
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• 2014

본 논문에서는 지연시간 최소화를 위한 고속 데이터 광 전송용 ADC 개발에 관한 연구를 진행하였다. 기존 광 중계기의 전송 방식은 데이터 신호 변환에서 $6{\mu}s$이상의 지연시간을 갖고 있어 고속 데이터 전송 및 신호 변환에 제한을 받고 있으므로 이를 직접 변환 방식을 이용하여 데이터 신호 변환 시 지연시간을 $2{\mu}s$ 이내로 줄이는 새로운 기술의 개발이 요구된다. 이동통신 LTE, LTE advanced 등의 서비스 전송망 구축에 필요한 신호변환 부품 핵심기술의 발전이 요구되고 있으므로, 본 논문에서는 신호변환 단계에서 지연시간을 획기적으로 줄일 수 있는 기술을 적용하여 $3{\mu}s$의 지연시간을 갖는 ADC를 개발하였다.