• 한국지열·수열에너지학회논문집
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• 제12권1호
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• pp.17-22
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• 2016

It is very important to obtain a out-of season production in horticultural greenhouses corresponding with higher crop prices. A ground source heat pump system has been highly spotlighed as an energy efficient heating system for the greenhouse. This paper investigated the operating cost of the ground source heat pump system with the variation of generating temperature and designing methods for heating system of the greenhouse. Even though the COP of the ground source heat pump system decreased with an increment of generating temperature in heating mode, the operating cost could be reduced. By adopting the high temperature heat pump system and heat storage tank, it could be achieved to save energy and reduce the operating time of auxiliary oil heating system for producing good plant-growth in the greenhouse.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1840-1845
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• 2005

The SoC and digital technology development recently enabled the emergence of information devices and control devices because the SoC present many advantages such as lower power consumption, greater reliability, and lower cost. It is required to use an embedded operating system for building control systems. So far, the Real-Time operating system is widely used to implement a Real-Time system since it meets developer's requirements. However, Real-Time operating systems reveal a lack of standards, expensive development, and license costs. Embedded Linux is able to overcome these disadvantages. In this paper, the implementation of control system platform using Real-Time Embedded Linux is described. As a control system platform, we use XScale of a Soc and build Real-Time control platform using RTAI and Real-Time device driver. Finally, we address the feasibility study of the Real-Time Embedded Linux as a Real-Time operating system for mobile robots.

• 한국경영과학회지
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• 제4권1호
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• pp.51-67
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• 1979

This paper considers the problem of determining an optimal dynamic operating policy for a two-stage tandem queueing service system in which the service facilities (or stages) can be operated at more than one service rate. At each period of the system's operation, the system manager must specify which of the available service rates is to be employed at each stage. The cost structure includes an operating cost for running each stage and a service facility profit earned when a service completion occurs at Stage 2. We assume that the system has a finite waiting capacity in front of each station and each customer requires two services which must be done in sequence, that is, customers must pass through Stage 1 and Stage 2 in that order. Processing must be in the order of arrival at each station. The objective is to minimize the total discounted expected cost in a two-stage tandem queueing service system, which we formulate as a Discrete-Time Markov Decision Process. We present analytical and numerical results that specify the form of the optimal dynamic operating policy for a two-stage tandem queueing service system.

• 한국레이저가공학회지
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• 제18권4호
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• pp.12-16
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• 2015

The research on multi electron beam systems is being carried out by various methods. We are studying multi electron beam system using miniaturized electron beam columns. The column consists of electrostatic lenses, electrostatic deflector and tip emitter. Our operating system controls 4 column array, captures images of each column and maintains the instrument. We present the usefulness of our operating system for multi columns by capturing images of each column.

• 전기의세계
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• 제24권5호
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• pp.97-102
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• 1975

This paper describes the result of a Study for the Optimum Operating method with Spinning reserve in case of outage of large generator unit to improve the system stability and prevent the system frequency drop. This is usually done by governor free operation, so we focused our attention to the operating Char acteristics of spinning reserve. Nexy, a study was made to mesure the upper limit of Spinning reserve and when this upper limit cannot match the required power, a relationship between the amount of spinning reserve and that of the load shedding requirement was searched with regard to several system operating conditions to use it in our future system operation. By this study, the optimum system operating method was recommended for reliable operation of power system.

• Journal of Biosystems Engineering
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• 제31권1호
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• pp.39-45
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• 2006

Fundamental informations on performance of sets of solenoid valve and nozzle were necessary to develop a target selectable spraying system. The experiments were performed for the sets of solenoid valves and flat spraying nozzles at 3 levels of the operating pressures, and the obtained results are as follows; Rise time of the system pressure to reach up to 90% of the operating pressure after the valve turned was affected by nozzle size and operating pressure. Maximum overshoot of the system pressure was about 170% not affected by the sets of valve and nozzle and operating pressure. The system pressure after its settle down within 5% of the set pressure showed good uniformity in any condition of the experiment as less as 2.3% of its coefficient of variation. Time requirement to lower the system pressure down to 50% after the valve power turned off was affected by valve and nozzle set and operating pressure.

• 한국정보통신학회논문지
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• 제10권1호
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• pp.156-163
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• 2006

본 고에서는 임베디드 시스템을 위한 운영체제를 평가하고 성능을 검사하는 것을 주안점으로 삼고 있으며 현재 상용화 되어있는 윈도우즈 플래포움을 기초로 하고 있다. 전형적인 컴퓨터의 workload 이용하고 시스템성능을 증가시키는 운영체제의 벤치마킹의 분석을 포함한 기본적인 방법과 동시에 하위레벨에서의 규명을 이루고 있다. 본 고에서는 "WinStone"과 "HBench" 같은 선택되어진 어플리케이션 중심과 직접적으로 시스템에 영향을 끼치는 가장최선의 벤치마킹툴이 사용되었다. 이 실험과 케이스 연구를 통하여 벤치마킹툴을 이용하여 윈도우즈 플래포움의 하위레벨 테스트와 동시에 어플리케이션 레벨의 임베디드 마이크로시스템의 성능을 보여 주고 있다.

• 한국항공우주학회지
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• 제39권11호
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• pp.1042-1051
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• 2011

본 논문에서는 복수 무인기의 편대 비행을 위한 탑재 무선 통신 및 임무통제 네트워크 (지상관제시스템)를 포함하는 통합 운영 시스템의 구성 방안을 제시한다. 이를 위해 편대비행을 위한 무인기에 탑재되는 시스템들의 구성 형태에 따라 다양한 운영 시스템들을 분류하였다. 또한 각각의 운영 시스템에 대한 장단점 및 고장에 대한 신뢰성을 파악하였다. 이 결과를 바탕으로 편대기의 임무비행을 수행하는데 있어 적절한 운영 시스템의 형태를 결정하고 구성 요소들을 개발하였다. 제안된 운영 시스템을 이용하면, 이종의 비행체로 편대를 구성할 수 있으며, 복잡한 임무를 여러 무인기에 나누어 수행 가능하고, 단일 임무의 협업 또는 다양한 임무의 동시 수행이 가능하다.

• 전기학회논문지
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• 제56권3호
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• pp.451-456
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• 2007

This paper presents a problem that reconfigure distribution power system using branch exchange method. Optimal reconfiguration problem calculates line loss, voltage condition about system states of all situations that become different according to line On/off status, and search for optimum composition of these. However, result is difficult to be calculated fast. Because radiated operation condition of system is satisfied using many connection and sectionalize switches in the distribution power system. Therefore, in this paper, optimization method for reducing system total loss and satisfying operating condition of radial and constraints condition of voltage is proposed using the fastest branch exchange. And optimal solution at branch exchange algorithm can be wrong estimated to local optimal solution according to initial operating state. Considering this particular, an initial operating point algorithm is added and this paper showed that optimal solution arrives at global optimal solution.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.674-677
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• 2012

운영체제는 컴퓨터 하드웨어와 컴퓨터 사용자간의 매개체 역할을 수행하는 것으로 사용자가 프로그램을 수행할 수 있는 환경을 제공한다. 따라서, 운영체제의 주된 목적은 컴퓨터를 편리하게 이용하는 것에 있고, 컴퓨터 하드웨어를 효율적으로 관리하는 데 있다. 컴퓨터를 이용하는 계층의 대중화, 하드웨어의 성능적 향상, 인터넷의 등장, 무선 네트워크의 활성화, 스마트폰 및 태블릿(Tablet) PC 등장, 가상화 기술 및 클라우드 컴퓨팅 등장 등은 운영체제 분야에도 변화를 주기 시작하였다. 특히 서버 가상화 기술을 기반으로 하는 클라우드 컴퓨팅 환경과 다양한 유무선기기를 활용한 인터넷 접속환경으로 인해 웹 기반 운영체제가 탄생하였다. 본 논문에서는 웹 기반 운영체제의 정의, 종류와 특징, 장단점에 대해 분석하고, 앞으로의 전망에 대해 알아본다.