• JSTS:Journal of Semiconductor Technology and Science
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• 제17권2호
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• pp.186-191
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• 2017

An integrated pressure-sensor system was developed using the sensor-conditioning processes, which resulted in the optimum sensitivity of the pressure-sensor through the signal amplification, noise reduction, and level shift. Due to the specified characteristics among the components, such as operation range, the sensor output was generally limited compared to the full scale of the reading when coupled with other parts. Devices fabricated exhibited comparable characteristics with higher pressure sensitivity to that of the pressure sensor without sensor-conditioning process. In this work, the sensor resolution was at least enhanced at least by 25% using the sensor-conditioning processes.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.621-626
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• 2008

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.344-346
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• 2006

In this paper, a novel algorithm for increasing the steady state efficiency during light load operation of the induction generator that integrated with a wind power generation system is presented. The proposed algorithm based on the flux level reduction, where the flux level is estimated using Support-Vector -Machines for regression (SVR) for the optimum d-axis current of the generator. SVR is trained off-line to estimate the unknown mapping between the system's inputs and outputs, and then is used online to calculate the optimum d-axis current for minimizing generator loss. The experimental results show that SVR can define the flux-power loss accurately and determine the optimum d-axis current value precisely. The loss minimization process is more effective at low wind speed and the percent of power saving can approach to 40%.

• 한국군사과학기술학회지
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• 제2권2호
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• pp.209-217
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• 1999

In this paper, an integrated S/W system from CAD to optimal design has been suggested and an application to a precision machine tool structure shown. The integrated system is so designed to reduce manual interfacing effort. An object-oriented programming language is used for combining 3-D CAD program, FEM and optimal design tools. In this system parametric modelling technique is applied and users can get the optimum design iteratively without much user intervention. The CAD model is automatically updated when the design parameters are transferred back to the CAD program. Not only design time can be dramatically reduced but unnecessary operation errors avoided by the integration.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.403-407
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• 2005

Objective of the research is to demonstrate solar thermal space and ground heating system which is integrated to a greenhouse culture facility for reducing heating cost, increasing the value of product by environment control, and developing advanced culture technology by deploying solar thermal system. Field test for the demonstration was carried out in horticulture complex in Jeju Island. Medium scale solar hot water system was installed in a ground heating culture facility. Reliability and economic aspect of the system which was operated complementary with thermal storage and solar hot water generation were analyzed by investigating collector efficiency, operation performance, and control features. Short term day test on element performance and Long term test of the whole system were carried out. Optimum operating condition and its characteristics were closely investigated by changing the control condition based on the temperature difference which is the most important operating parameter. For establishing more reliable and optimal design data regarding system scale and operation condition, continuous operation and monitoring on the system need to be further carried out. However, it is expected that, in high-insolation areas where large-scale ground storage is adaptable, solar system demonstrated in the research could be economically competitive and promisingly disseminate over various application areas.

• 신재생에너지
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• 제1권2호
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• pp.53-59
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• 2005

Objective of the research is to demonstrate solar thermal space and ground heating system which is integrated to a green-house culture facility for reducing healing cost, Increasing the value of product by environment control, and developing advanced culture technology by deploying solar thermal system. Field test for the demonstration was carried out in horticulture complex In Jeju Island. Medium scale solar hot water system was installed in a ground heating culture facility. Reliability and economic aspect of the system which was operated complementary with thermal storage and solar hot water generation were analyzed by investigating collector efficiency, operation performance, and control features. Short term day test on element performance and Long term test of the whole system were carried out. Optimum operating condition and its characteristics were closely Investigated by changing the control condition based on the temperature difference which Is the most important operating parameter For establishing more reliable and optimal design data regarding system scale and operation condition, continuous operation and monitoring on the system need to be further carried out. However, It is expected that, in high-insolation areas where large-scale ground storage is adaptable, solar system demonstrated in the research could be economically competitive and promisingly disseminate over various application areas.

• 에너지공학
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• 제18권4호
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• pp.221-229
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• 2009

본 연구에서는 지역난방 수도권 지사별 실태 및 영향인자 진단 분석을 통해 개별지사와 연계지사간의 효율적이며 경제적인 운전을 할 수 있는 최적화 운전 프로그램을 개발하고 이를 통해 실제보다 최적화 운전시 어느정도 경제적 효과가 있는지를 확인해 보고자 하였다. 이를 위해 각 지사별 실태조사를 통해 보일러, 펌프, 관련Tag(온도, 압력, 연료량)등 다양한 인자를 진단/분석하였고 최적화 프로그램 개발을 위해 방대한 1년간 데이터를 인자별 Data base를 구축할 수 있었다. 또한 이를 통해 지사별 최적화 프로그램을 개발하여 수행한 결과, 최적화 선호도는 "소각장 >한전수열 >CHP >PLBs >PLBw"이었으며 연계를 제외한 각 지사별 실제운전과 최적화 운전 비용차이가 거의 없었다. 한편, 통합운영 최적화 프로그램을 개발하여 실제와 동일한 총 생산열량과 동일한 한전수열량과 같은 고정인자는 변동치 않고 단지 연계공급/수급열량만을 프로그램을 통해 최적조건(가장 저렴하고 효율적인 열량을 우선공급하는 조건)으로 효율적으로 운전한 결과, 사계절별 임의로 선정된 2~4일에 대한 일일 절감율 2.45~6.80%, 일일 절감액 22,727천원~60,077천원을 나타내었는데, 특히 겨울철에 제일 많은 수요량을 나타내며 가장 많은 절감비용을 얻을 수 있었고 수요량이 적은 여름철이 절감비용이 가장 작았다. 이러한 결과를 토대로 1년간 실제 열량 생산비용 대비 연간 절감비용을 환산하면 이론적으로 84억원이며 이는 수도권 전지사의 연간 총 열생산 비용(3,070억원)의 2.74%이상을 절감하는 경제적 효과가 있음을 확인할 수 있었다.

• Smart Structures and Systems
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• 제13권3호
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• pp.407-418
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• 2014

The purpose of this paper is to present an Integrated Life Cycle Bridge Information Modeling that can be used throughout different phases of the bridge life cycle including: design, construction, and operation and maintenance phases. Bridge Information Modeling (BrIM) has become an effective tool in bridge engineering and construction. It has been used in obtaining accurate shop drawings, cost estimation, and visualization. In this paper, BrIM is used as an integrated tool for bridges life cycle information modeling. In the design phase, BrIM model can be used in obtaining optimum construction methods and performing structural advanced analysis. During construction phase, the model selects the appropriate locations for mobile cranes, monitors the status of precast components, and controls documents. Whereas, it acts as a tool for bridge management system in operation and maintenance phase. The paper provides a detailed description for each use of BrIM model in design, construction, and operation and maintenance phases of bridges. It is proven that BrIM is an effective tool for bridge management systems throughout their life phases.

• 상하수도학회지
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• 제31권1호
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• pp.1-6
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• 2017

Surge pressure is created by rapid change of flow rate due to operation of hydraulic component or accident of pipeline. Proper control of surge pressure in distribution system is important because it can damage pipeline and may have the potential to degrade water quality by pipe leakage due to surge pressure. Surge relief valve(SRV) is one of the most widely used devices and it is important to determine proper parameters for SRV's installation and operation. In this research, determining optimum parameters affecting performance of the SRV were investigated. We proposed the methodology for finding combination of parameters for best performance of the SRV. Therefore, the objective function for evaluate fitness of candidate parameters and surge pressure simulation software was developed to validate proposed parameters for SRV. The developed software was integrated into genetic algorithm(GA) to find best combination of parameters.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.400-408
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• 2009

Simulation applications for analyzing the productivity of construction operations at operation level and project schedules at project level are crucial methods in project management. The application at two different levels should be very tightly linked to each other in practice. However, appropriate integration at the levels is not achieved in that existing systems do not support to integrate operation models into a schedule model. This paper presents a new approach named to Discrete Event Simulation-Nesting modeling approach, which supports not only productivity analysis at operation level but also schedule management at a project level. The system developed by the authors allows creating operation models at the operation level, maintaining them in operation model library, executing sensitivity analysis to find the behaviors of the operation models when different combination of resources are used as existing DES systems do. On top of the conventional functions, the new system facilitates to find the optimum solution of resource combinations which satisfy the user's interest by computing the hourly productivity and the hourly cost of the operation. By drag-and-dropping an operation model kept in the operation model library, the operation models are integrated into an activity of the schedule model. When a complete schedule model is established by nesting operation models into the schedule model, stochastic simulation based scheduling is executed. A case study is presented to demonstrate the new simulation system and verify the validity of the system.