• 한국진공학회:학술대회논문집
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• 한국진공학회 2005년도 제28회 학술발표회 초록집
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• pp.147-147
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• 2005

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 하계 학술대회 논문집
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• pp.22-28
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• 2000

• Journal of Welding and Joining
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• 제20권3호
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• pp.31-36
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• 2002

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.251-252
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• 2018

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1110-1116
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• 1993

A study on optimum operation performances of power efficiency, economy and exhaust emissions for a tractor was conducted. A mathematical model of multiple degree polynomial equation was applied to established the function of solid multiple parameter curves for specific fuel consumption (ge), cabon monoxide (CO) ,hydrcarbons (HC) and cabonaceous smoke (Rb). The optimum operation theorems for economy operation indicated by ge and for exhaust emissions described by Co , HC and Rb were obtained from analytical method and performance test data. The optimum operation theorems could exhibit optimum operation working points, curves, and regions. The optimum matching relations of engine speed and transmission parameters were analyzed by using computer simulation methods in accordance with the tractor specifications , actual farm working conditions in a typical drawbar pull work such as plowing , the optimum operation objective function, the ideal transmission ratio, practical gear shif ing positions and practical travel speed of the tractor TN55 medel. The results of the anlayzes indicated clearly that the optimum power efficient operation, energy saving and pollution reducing would be realized if the tractor would be operated according to theoptimum operation methods.

• 대한환경공학회지
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• 제33권5호
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• pp.353-358
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• 2011

본 연구에서는 막 접촉기에서 운전조건에 따른 암모니아 제거 특성에 대해 알아보았다. 물질 전달 계수를 이용하여 각 조건에서의 암모니아 제거효율을 정량적으로 비교하였다. PTFE 재질의 막을 이용한 본 시스템에서 빠른 시간 내에 효율적으로 암모니아 탈기가 가능하였다. 여러 가지 운전조건 항목 중에서 접촉시간과 용액의 pH가 전체 제거 효율에 가장 큰 영향을 미치는 것으로 나타났다. 다른 가압 방식의 막 분리 공정과는 다르게 본 공정에서는 유입수의 고형물질에 의해 효율이 감소하는 현상은 발견되지 않았다. 또한, 삼투 증류(osmotic distillation)에 의해 물질 전달 효율이 감소하는 현상은 흡수용액의 온도를 증가시키는 것으로 해결할 수 있었다. 본 연구에 사용한 막 접촉기 시스템은 유입수와 흡수용액(stripping solution)의 유속, 유입수의 pH 등을 최적화 할 경우에 고농도 암모니아 제거에 효과적으로 사용할 수 있을 것이라 예상된다.

• International Journal of Precision Engineering and Manufacturing
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• 제2권3호
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• pp.69-78
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• 2001

This paper presents a process and operation planning system and an NC code post-processor for effective machining of press dies for production of cars. Based on the machining feature, major parts of press dies are categorized into 15 groups and a standard process plan is defined for each group. The standard process plan consists of a series of processes where a process is defined as a group of operations that can be done with one setup. Details such as cutting tools, cutting conditions, and tool paths are decided at the operation planning stage. At the final stage of process and operation planning, the NC code post-processor adjusts feedrates along the tool path to reduce machining time while maintaining the quality. The adjustment rule is selected based on the machining load estimated by virtual machining.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1024-1030
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• 1993

In manufacturing press die with free surface, grinding operation is an important post process for surface finish and dimensional accuracy. With the advancement of NC technology. surface grinding operation is increasingly replaced by the gantry type manipulator. As the mechanics for grinding operation is different from machining operation, conventional CAM system for machining operation is hard to apply. In this. paper, we develop a five-axis CAM system by which an efficient gantry trajectory can be planned and verified. The developed system consists of four conceptual modules; namely CAD, PROCESS. CAM, and ANALYSIS. In the CAD module, the machined surface is represented by CL-data or surface modeler, and process parameters are specified by the PROCESS module. Then, the CAM module generates a series of grinding paths based on the grinding mechanics together with process databases for tool spaces and grinding conditions. The generated paths are verified via ANALYSIS module. Validation via real experiments is left for further study.

• 전력전자학회논문지
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• 제3권4호
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• pp.426-436
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• 1998

Identification of fault current during the operation of a power semiconductor switch and activation of suitable remedial actions are important for reliable operation of power converters. A short circuit is a basic and severe fault situation in a circuit structure such as voltage source converters. This paper presents a new active protection circuit for fast and precise clamping and safe shutdown of fault currents of the IGBTs. This circuit allows operation of the IGBTs with a higher on-state gate voltage, which can thereby reduce the conduction loss in the device without compromising the short circuit protection characteristics. The operation of the circuit is studied under various conditions, considering variation of temperature, rising rate of fault current, gate voltage value, and protection circuit parameters. An evaluation of the operation of the circuit is made using IGBTs from different to confirm the effectiveness of the protection circuit.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.62-63
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• 2016

Existing studies relative to enhancing sustainability of earth-work are mainly involved in the performance of construction equipments. They assume that there is no variation of the engine power and fuel consumption and classify the dozer operation into working and idle conditions. They enable to find the most eco-friendly equipment fleet deployment plan. However, they are confined in that they do not provide a measure to assess the sustainability of the operation plan and suggest optimal alternative(s). This paper presents a method that identifies an optimal dozer operation plan that assures sustainability by reducing fuel consumption of the equipment. The method computes the dozer operation productivity using engine-torque-output map provided by equipment manufacturers. Indeed, it identifies the eco-dozing operation that minimizes fuel consumption and maximizes the target productivity.