• 전기학회논문지
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• 제67권3호
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• pp.479-484
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• 2018

This paper describes domestic technical standard of Photovoltaic(PV) PCS(Power Conditioning Systems)-Characteristics of the utility interface. This standard tests utility compatibility and personnel safety and equipment protection of PV inverter performance functions. Especially utility compatibility part includes test items of 1)voltage, current and frequency, 2)normal voltage operating range, 3)DC injection, 4)normal frequency operating range, 5)harmonics and 6)waveform distortion, 7)power factor of PV inverter. Therefore in this paper each test item of domestic technical standard is studied and analyzed and finally full tested by PV inverter performance function.

• 조명전기설비학회논문지
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• 제25권4호
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• pp.71-78
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• 2011

This paper contains the selection of operation parameters for protection and control of steam turbine in a Korea Standard Type Nuclear Power Plant. The safety of nuclear reactor must be ensured which generates nuclear energy and produces steam. Also, the safety of turbine, which consume the nuclear energy as a core machine, must be ensured. For the purpose of this, we describe how the operating parameters were selected, reviewed, implemented into the operator console and finally put into actual operation of the system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1079-1081
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• 1999

This paper presents the standard for dividing/tieing the distribution lines and installing optimally the automated distribution switch-gear in multi-line faults. Also this paper recommends the distribution system design in consideration of the live load transfer of the concentrated load in the last load-side. This recommendation will be useful for designing the distribution network, developing the feeder automation software and operating the distribution automation system.

• 한국안전학회지
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• 제33권5호
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• pp.21-27
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• 2018

The purpose of this study is to develop a SOP (Standard Operating Procedure) for a distribution board that can monitor the leakage current of a load distribution line in real time. The developed distribution board was fabricated by applying IEC 61439-1. It consists of the distribution board and an alarm device. The work process for making the distribution board was compliant with the KEMC (Korea Electrical Manufacturers Cooperative) regulations. And the AC distribution board range is 1,000 V. In addition, the voltage in DC is less than 1500 V. The distribution board receives a 3-phases and 4-wires power supply system and can supply power to the load of a maximum of 32 single or three phase distribution circuits. Also, leakage current measured on the power distribution board was used by sensors installed. The SOP of the developed distribution board consists of the installation standards for the short circuit alarm device and sensor, the surge protection device, switches and indication lamps, and other devices. The operation procedure was prepared so that each manufacturing step of the distribution board must be confirmed by the persons in charge of preparation, production, quality control and approval before moving forward to the next step.

• 한국콘텐츠학회논문지
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• 제15권4호
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• pp.17-28
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• 2015

운영체제 상에서 동작하는 응용프로그램은 운영체제의 환경과 지원하는 표준 라이브러리들이 다르기 때문에 운영체제에 매우 높은 의존성을 가진다. 이러한 이유로 동일한 기능을 수행하는 응용프로그램도 운영체제에 따라 새롭게 구현해야 되며 이는 응용프로그램 개발 이후의 유지 보수나 관리 측면에서도 시간적, 경제적 낭비를 초래한다. 이를 해결하기 위해 Cygwin이나 MinGW 등의 연구가 진행되고 있지만, 가상환경이나 툴을 제공하는 것일 뿐 응용프로그램 자체에 대한 이식성을 지원하는 것은 아니다. 따라서 본 논문에서는 표준 C라이브러리와 POSIX를 이용한 래퍼 형식의 범용 운영체제를 위한 인터페이스 미들웨어를 설계하여 응용프로그램이 가상환경이나 코드 수정 없이 동일한 동작을 지원한다. 미들웨어는 API를 기본과 확장으로 분류해 선택적으로 적재하여 응용프로그램의 크기를 효율적으로 관리할 수 있도록 한다. 또한, 응용프로그램을 인터페이스 미들웨어를 탑재한 Linux, Unix, Windows와 Cygwin을 비교 실험하고 기능 및 성능 평가를 수행하였다.

• 한국문헌정보학회지
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• 제56권3호
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• pp.153-179
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• 2022

본 연구에서는 표준현장실습학기제의 도입의 가능성과 무급운영이 가능한 자율 현장실습학기제 운영가능성에 대해서 살펴보고, 현장실습기관들을 대상으로 설문조사를 함으로써 이들의 인식조사를 기반으로 한 대응전략을 제안해 보고자 하였다. 연구결과, 첫째, 실습기관의 직무관련 교육시간의 배정시간을 포함하여 운영시간 및 운영방식에 대해서는 매우 낮은 인식을 보여주고 있음을 알 수 있다. 둘째, 표준현장실습의 도입상황에 대해서 매우 낮은 인지도를 보여 주었고, 표준현장실습의 내용, 표준현장실습 운영서 및 협약 내용, 표준현장실습 내용 변경 사실, 표준현장실습 수행시 실습 지원비, 표준현장실습 근로계약에 관한 구체적인 내용, 실습기관의 요건 충족도 등에서 매우 낮은 인식도를 보여 주었으며, 다만 표준현장실습의 도입 배경에 대해서는 이해하고 공감하는 것으로 보인다. 이를 기반으로 본 연구에서는 설문조사를 포함한 문헌연구를 기반으로 표준현장실습 도입시 고려 사항으로, 표준현장실습학기제 적용제외 대상으로 법개정, 표준현장실습학기 또는 자율현장실습학기제 채택 고민, 현장실습기관의 충분한 확보 및 공유, 그리고 현장실습매뉴얼의 개발과 공동활용 등이다.

• 한국물환경학회지
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• 제22권5호
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• pp.905-912
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• 2006

In this paper, simulation methods of the system dynamics model developed by Das et al. (1997) for activated-sludge wastewater treatment plants are illustrated in an attempt to determine the operating rules and the policies related to capacity expansion of an activated-sludge wastewater treatment plant. For existing conditions, the analyses were performed by varying activated-sludge return rate to observe changes in effluent water quality and treatment efficiency. The effluent water quality is also analyzed for various average daily inflow conditions and activated-sludge return rates. As a result, without expanding the aeration tank, maximum average daily inflow that can satisfy the effluent water quality standard of BOD $0.02kg/m^3$ was determined as $2,840m^3/hr$, subject to 100% of activated-sludge return rate while other factors remain constant. When the activated-sludge return rate is less than 100%, expansion of the aeration tank is necessary and minimum sizes of the aeration tank to satisfy the effluent water quality standard were determined for various activated-sludge return rates. In addition, the total operating and maintenance as well as unit treatment cost regression equations for activated-sludge wastewater treatment plants are suggested by using the cost data that are obtained from Water and Wastewater Division, Ministry of Environment. The regression analyses showed that the economies of scale phenomena exist in the operating and maintenance costs of activated-sludge wastewater treatment plants.

• 한국IT서비스학회지
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• 제19권3호
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• pp.139-149
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• 2020

There are now many different commercial weather sensors suitable for smart farms, and various smart farm devices are being developed and distributed by companies participating in the government-led smart farm expansion project. However, most do not comply with standard specifications and are therefore limited to use in smart farms. This paper proposed the connecting structure of operating non-standard node devices in smart farms following standard specifications supporting smart greenhouse. This connecting structure was proposed as both a virtual node module method and a virtual node wrapper method. In addition, the SoftFarm2.0 system was experimentally operated to analyze the performance of the implementation of the two methods. SoftFarm2.0 system complies with the standard specifications and supports non-standard smart farm devices. According to the analysis results, both methods do not significantly affect performance in the operation of the smart farm. Therefore, it would be good to select and implement the method suitable for each non-standard smart farm device considering environmental constraints such as power, space, distance of communication between the gateway and the node of the smart farm, and software openness. This will greatly contribute to the spread of smart farms by maximizing deployment cost savings.

• 한국안전학회지
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• 제36권3호
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• pp.74-80
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• 2021

Korea Atomic Energy Research Institute (KAERI) has been operating an integral effects test facility, the Advanced Thermal-Hydraulic Test Loop for Accident Simulation (ATLAS), according to APR1400 for transient experimental and design basis accident simulation. Moreover, based on the experimental data, the domestic standard problem (DSP) program has been conducted in Korea to validate system codes. Recently, through DSP-05, the performance of the passive auxiliary feedwater system (PAFS) in the event of multiple steam generator tube rupture (MSGTR) has been analyzed. However, some errors exist in the reference input model distributed for DSP-05. Furthermore, the calculation results of the heat loss correlation for the secondary system presented in the technical report of the reference indicate that a large difference is present in heat loss from the target value. Thus, in this study, the reference model is corrected using the geometric information from the design report and drawings of ATLAS. Additionally, a new heat loss correlation is suggested by fitting the results of the heat loss tests. Herein, MSGTR-PAFS accident analysis is performed using MARS-KS 1.5 with the improved model. The steady-state calculation results do not significantly differ from the experimental values, and the overall physical behavior of the transient state is properly predicted. Particularly, the predicted operating time of PAFS is similar to the experimental results obtained by the modified model. Furthermore, the operating time of PAFS varies according to the heat loss of the secondary system, and the sensitivity analysis results for the heat loss of the secondary system are presented.

• Journal of Biosystems Engineering
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• 제43권1호
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• pp.72-80
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• 2018

Purpose: A modern greenhouse consists of various Information and Communications Technology (ICT) components e.g., sensor nodes, actuator nodes, gateways, controllers, and operating softwarethat communicate with each other. The interoperability between these components is an essential characteristic for any greenhouse control system. A greenhouse control system could not work unless the components communicate via common interfaces. The TTAK.KO-06.0288 is an interface standard consisting of four parts. Notably, TTAK.KO-06.0288-Part3, which describes the interface between a greenhouse operating system (GOS) and a greenhouse control gateway (GCG), is the core standard of TTAK.KO-06.0288. The objectives of this study were to analyze the TTAK.KO-06.0288-Part3 standard, to suggest alternative solutions for identified issues, and to develop a library as a proof of the alternative solutions. Methods: The "data field" was analyzed using a comparative analysis method, since it is a data transmission unit of TTAK.KO-06.0288-Part3. It was compared with other parts of TTAK.KO-06.0288 in terms of definition, format, size, and possible values. Although TTAK.KO-06.0288-Part1 and TTAK.KO-06.0288-Part2 do not use a "data field," they have a similar data structure. That structure was compared with the "data field" of TTAK.KO-06.0288-Part3. Results: Twenty-one issues were identified across four categories: inter-standard issues, intra-standard issues, operational issues, and misprint issues. Since some of the issues can raise interoperability problems, 16 alternative solutions were suggested. In order to prove the alternative solutions, an open-source communication library called libtp3 was developed. The library passed 14 unit tests and was adapted to two research. Conclusions: Although TTAK.KO-06.0288-Part3 is an interface standard for communication between a GOS and a GCG, it might not communicate between different implementations because of the identified issues in the standard. These issues could be solved by the alternative solutions, which could be used to revise TTAK.KO-06.0288. In addition, a relevant organization should develop a program for compatibility testing and should pursue test products for smart greenhouses.