• 교육시설
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• 제22권5호
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• pp.18-23
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• 2015

• 정보처리학회논문지A
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• 제17A권3호
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• pp.127-136
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• 2010

무선 센서네트워크는 유비쿼터스 컴퓨팅에서 생활환경과 컴퓨터 사이의 중계자 역할을 하는 매우 중요한 연구 분야이다. 매우 제약적인 자원 환경에서 동작하여야 하는 센서 노드의 특성 때문에 제한된 자원을 효율적으로 관리할 수 있는 센서네트워크 운영체제가 요구된다. 또한 센서네트워크는 외부 물리 환경의 변화에 반응하여 동작하는 시스템이기 때문에 여러 이벤트를 동시에 신속하게 처리 할 수 있어야 한다. 이러한 요구조건을 만족시킬 수 있도록 TinyOS나 MANTIS, NanoQplus 등 센서네트워크용 운영체제에서 다양한 기법들이 제시되고 있다. 하지만, 센서네트워크 응용 프로그램을 개발하는 프로그래머 입장에서는 제약이 심한 개발 환경과 개발을 용이하게 할 수 있도록 하는 프레임워크가 부족한 문제점도 매우 크다. 이를 위해 본 논문에서는 반응형 시스템에 적합한 상태머신 프레임워크를 멀티쓰레드 기반의 센서네트워크운영체제인 NanoQplus에 구현하였다. 또한 효과적인 이벤트 처리를 위한 이벤트 브로커 모듈 및 상태머신간 메시지 공유를 위한 메시지 자료구조와 메시지 및 메시지큐를 핸들링하고 상태머신의 전이를 수행하는 실행 모듈을 제안한다. 추가적으로 상태머신 프레임워크기반의 응용 프로그램을 좀 더 용이한 개발을 지원할 수 있는 CASE(Computer-aided software engineering)툴을 개발하였다.

• 대한기계학회논문집B
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• 제41권8호
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• pp.511-519
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• 2017

태양열 및 발전기의 배기가스 폐열을 복합열원으로 이용하여 작동되는 하이브리드 태양열 해수담수기의 성능을 증가시키기 위한 실험을 수행하였다. 실험 장비는 집열 면적이 $1m{\times}2m$인 단순 태양열 증류기와 수직 다중효용부로 구성되어 있다. 실험은 두 대의 동일한 하이브리드 태양열 해수담수기에 대하여 태양열을 열원으로 실외에서 다양한 운전 조건으로 수행하였다. 실험 결과 하이브리드 태양열 해수담수기의 담수 생산량은 다양한 운전 조건에 의존하였다. 태양열 증류기의 측면 유리에 단열을 하는 것과 낮은 초기 베이진 해수 수위는 태양열 해수담수기의 성능을 증가시켰다. 반사율이 평균 47%보다 낮은 반사휜의 적용은 예상과 다르게 총 생산량을 감소시켰다. 그러나 다중효용부로 공급하는 해수 공급 유량은 실험 범위 내에서 생산량에 명확한 영향을 보이지 않았다.

• 한국물환경학회지
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• 제37권2호
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• pp.128-136
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• 2021

It is generally known that a wastewater treatment plant (WWTP) consumes immense energy even if it can produce energy. With an aim to increase the energy independence rate of WWTP from 3.5% in 2010 to 50% in 2030, the Korean government has invested enormous research funds. In this study, cost-effective operating alternatives were investigated by analyzing the energy efficiency and economic feasibility for biogas and power generation using new and renewable energy. Based on the US EPA Energy Conservation Measures and Korea ESCO projects, energy production and independence rate were also analyzed. The main energy consumption equipment in WWTP is the blower for aeration, discharge pump for effluent, and pump for influent. Considering the processes of WWTP, the specific energy consumption rate of the process using media and MBR was the lowest (0.549 kWh/㎥) and the highest (1.427 kWh/㎥), respectively. Energy-saving by enhancing anaerobic digester efficiency was turned out to be efficient when in conjunction with stable wastewater treatment. The result of economic analysis (B/C ratio) was 2.5 for digestive gas power generation, 0.86 for small hydropower, 0.49 for solar energy, and 0.15 for wind energy, respectively. Furthermore, it was observed that the energy independence rate could be enhanced by installing energy production facilities such as solar and small hydropower and reducing energy consumption via the replacement of high-efficiency operating.

• 상하수도학회지
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• 제35권1호
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• pp.1-14
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• 2021

Eutrophication and algal blooms can lead to increase of taste and odor compounds and health problems by cyanobacterial toxins. To cope with these eco-social issues, Ministry of Environment in Korea has been reinforcing the effluent standards of wastewater treatment facilities. As a result, various advanced phosphorus removal processes have been adopted in each wastewater treatment plant nation-widely. However, a lot of existing advanced wastewater treatment processes have been facing the problems of expensive cost in operation and excessive sludge production caused by high dosage of coagulant. In this study, the sedimentation and dissolved air flotation (SeDAF) process integrated with sedimentation and flotation has been developed for enhanced phosphorus removal in wastewater treatment facilities. Design and operating parameters of the SeDAF process with the capacity of 100 ㎥/d were determined, and a demonstration plant has been installed and operated at I wastewater treatment facility (located in Gyeonggi-do) for the verification of field applicability. Several empirical evaluations for the SeDAF process were performed at demonstration-plant scale, and the results showed clearly that T-P and turbidity values of treated water were to satisfy the highest effluent standards below 0.2 mg/L and 2.0 NTU stably for all of operation cases.

• 제어로봇시스템학회논문지
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• 제21권2호
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• pp.87-94
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• 2015

This paper proposes a situation awareness method based on data fusion and independent objects for autonomous driving in on-road environment. The proposed method, designed to achieve an accurate analysis of driving situations in on-road environment, executes preprocessing tasks that include coordinate transformations, data filtering, and data fusion and independent object based situation assessment to evaluate the collision risks of driving situations and calculate a desired velocity. The method was implemented in an open-source robot operating system called ROS and tested on a closed road with other vehicles. It performed successfully in several scenarios similar to a real road environment.

• 한국유기농업학회지
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• 제25권3호
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• pp.523-536
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• 2017

The purpose of this study is to present operating directions of school food service center (SFSC) for development of environment-friendly agricultural producers (EFAP) and regional agriculture. Of eight SFSCs being operated in Chungcheongnam-do, this study analyzed situations of three cases, Cheonan, Asan and Hongseong. The analysis on operation situations revealed that all the three cases had positive economic effects on EFAP in the aspect of low commission and fixed supply price for a given period. The survey showed that social and economic changes since participating in the SFSC were largest in Asan. The awareness of the economic effects was largest among the producers in Cheonan.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.268-272
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• 2003

Large medical images in PACS are compressed for saving storage space and improving network speed. The integrated compression environment was designed and developed for uniting of various compression methods. Various compression algorithm-RLE compression, lossless JEPG, JPEG, was built into it, complying with DICOM. A image compression using DWT was also implemented in it. And a unified algorithm of lossless compression and lossy compression was designed to improve images quality and to make compression ratios high. And integrated compression environment was operating together with a database program for efficient and user-friendly management.

• 제어로봇시스템학회논문지
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• 제5권5호
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• pp.622-629
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• 1999

This paper discusses a real time multi-tasking system model and a development environment for an elevator control system. Recently, as the elevator systems become large-scaled and operate with high speed, there are lots of software tasks to be processed with time constraints. Thus, the control systems are designed with distributed control structure and characteristics of typical real time systems. For stuructural design of such real time system, we introduce a multi-tasking model based on a real time operating system model and an software development environment based on virtual protopyping which simulates real system operation in the cross development of a new elevator system with distributed control structure and its system reliability can be verified through numerous field tests.

• 한국주거학회논문집
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• 제12권1호
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• pp.85-92
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• 2001

The purpose of this study is to investigate the characteristic of the thermal environment at a living room by the heating system(floor radiation heating, forced convection heating, combined heating, radiation convection heating), and to compares the change of the thermal environment after operating the heating with after the operation stopped based on the floor radiation heating. This study proposes the basic data for the design and the development of the thermal storage structure heating system which not only utilizes fully the characteristic of the comfortable thermal environment but also reduces the preheating period and be able to use the off-peak electricity.