• 한국광학회지
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• 제6권4호
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• pp.266-273
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• 1995

칼라영상센서의 분광감응 특성은 칼라영상의 색을 결정하는 중요한 요인이 된다. 칼라영상센서의 분광특성을 간편하게 측정할 수 있는 장치를 제작하고 이를 사용하여 CCD 칼라 카메라의 분광특성을 조사하였다. 측정장치는 가시광선 영역내에서 단색광의 파장뿐만아니라 세기도 간편하게 조절할 수 있도록 제작된 광학부와 칼라영상센서의 출력신호를 디지탈값으로 처리하여 나타내는 색분석부로 구성되었다. 광학부에서 만들어진 단색광들에 대한 카메라의 출력값 R, G, B를 측정하였으며 이로부터 카메라의 연색성 및 선형성을 평가하였다. 이로써 제작된 측정장치가 칼라영상센서의 분광특성 측정 및 성능평가에 매우 유용함을 확인할 수 있었다.

• International Journal of Automotive Technology
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• 제6권3호
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• pp.235-242
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• 2005

This study introduces the Reliability-Based Design Optimization (RBDO) to enhance the kinematic and compliance (K & C) characteristics of automotive suspension system. In previous studies, the deterministic optimization has been performed to enhance the K & C characteristics. Unfortunately, uncertainties in the real world have not been considered in the deterministic optimization. In the design of suspension system, design variables with the uncertainties, such as the bushing stiffness, have a great influence on the variation of the suspension performances. There is a need to quantify these uncertainties and to apply the RBDO to obtain the design, satisfying the target reliability level. In this research, design variables including uncertainties are dealt as random variables and reliability of the suspension performances, which are related the K & C characteristics, are quantified and the RBDO is performed. The RBD-optimum is compared with the deterministic optimum to verify the enhancement in reliability. Thus, the reliability of the suspension performances is estimated and the RBD-optimum, satisfying the target reliability level, is determined.

• 한국통신학회논문지
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• 제28권8B호
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• pp.691-698
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• 2003

네트워크의 QoS를 지원하기 위해서는 환경변화에 동적으로 대처할 수 있는 자원관리 시스템이 필요하며, 이를 위해 고전적인 제어기술 분야에 사용되는 적응적인 시스템을 도입할 수 있다. 제어기술의 적용을 위해서는 네트워크의 대역폭 할당에 따른 전송률 응답특성을 구현해주는 모델의 개발이 필수적이라고 할 수 있다. 본 연구에서는 두 가지 방식의 네트워크 모델을 제안하였다. 첫째는 "동적 시스템 모델"이며 다른 하나는 "통계학적 모델"이다. 동적 시스템 모델은 네트워크의 동적 특성을 고려하여 도입하였으며, 통계학적 모델은 측정된 전송량 데이터의 분포를 고려하여 도입하였다. 제시된 두 모델의 인자 결정을 위해 최적화 기법을 사용하였으며, 제시된 두 모델이 실제 네트워크의 동작과 유사함을 살펴보았다.

• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1398-1406
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• 2018

Owing to the consistent increase in accurate analysis issue for energy consumption of the AC electric railway systems, there is controversy about the adequacy of the present watt-hour metering configuration. Due to the unusual load characteristics and facilities, the discussions have not been active. Therefore, in order to achieve more accurate watt-hour metering for AC electric railway system, this paper proposes numerical formulas for watt-hour metering that reflects the highly-varying characteristics of the railway load and the structural characteristics of the Scott transformer. The proposed formulas have been verified by comparison with site-measured data, and a more suitable metering configuration for AC railway system has been proposed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1793-1794
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• 2007

Since it has an advantage of possibility to control using experimentally given coefficient, PID Control is the most widely used method of control in the field of industry. However, since PID controller is not able to reflect the inherent characteristics of individual systems, it needs to be accompanied by additional techniques to supplement. Also, it has disadvantage that it is hard to find a satisfactory coeffi cient when the state of the system's dynamic characteristics and static characteristics are different each other. When the dynamic one shows up, it means the state of system shows a great amount of difference from that of desired such as the moment of beginning control or change of desired state. But, if the state of the system comes close to the desired state, the static characteristics shows up in the system. There are many solutions suggested to overcome problems according to the conversion of two examples of motion shown above. This paper is to confirm PID control's integration ingredient windup phenomenon, and experiment through technique of pre vention of windup actually using PLC(Programmable Logic Co ntroller), and to verify the change in characteristics of control.

• 한국태양에너지학회 논문집
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• 제26권3호
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• pp.1-8
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• 2006

The objective of this research is to study on the analysis of long-term performance characteristics of various solar thermal system for heating protected horticulture system for reducing heating cost, increasing the value of product by environment control, and developing advanced culture technology by deploying solar thermal system. Long term field test for the demonstration was carried out in horticulture complex in Jeju Island. 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. 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. 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.

• 동력기계공학회지
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• 제19권2호
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• pp.40-48
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• 2015

As advantages of LPG-DI engine, LPG is directly injected into combustion chamber during compression stroke to reduce compression temperature, prevent knock and spontaneous combustion, and adjust engine output using the amount of directly injected fuel, thereby reducing pumping loss caused by throttle valve. Stratified charge can be supplied nearby spark plugs to allow for overall lean combustion, which improves thermal efficiency and can cope with problems regarding emission regulations. In addition, it is characterized by free designing of intake manifold. Despite the fact that LPG-DI has many advantages as described above, there is lack of detailed investigation and study on spray characteristics, combustion flame characteristics, and ignition probability. In this study, a visualization experiment system that consists of visualization combustion chamber, air supply control system, emission control system, LPG fuel supply system, electronic control system and image data acquisition system was designed and manufactured. For supply of stratified charge in the combustion chamber, alignment of injector and spark plugs was made linear.

• 동력기계공학회지
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• 제17권6호
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• pp.63-72
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• 2013

The main purpose of this study is to analyze the collection characteristics of multi-layer multi-stage porous plate system with ionizer and dielectric-substance experimentally. The experiment is carried out to analyze the characteristics of pressure drop and collection efficiency for the present system with experimental parameters such as applied voltage, inlet velocity, stage number and inlet particle concentration, etc. In results, for multi-layer multi-stage porous plate system of inflow type, at 5 stage and $v_{in}$=2.58 m/s, the pressure drop becomes lower 15 $mmH_2O$ as 95 $mmH_2O$ than that of non-inflow type system. It is estimated that for the present system with ionizer and dielectric-substance, the collection efficiency represents 98.5% showing higher 5.2% comparing to that of multi-layer multi-stage porous plate system without ionizer and dielectric-substance at 5 stage, $v_{in}$=2.58 m/s and inlet concentration $3g/m^3$(fly ash).

• 수산해양기술연구
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• 제36권1호
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• pp.12-24
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• 2000

The electro-hydraulic servo winch system built in a automatic tension control equipment was designed with a latent need for an advanced system in fishing operations of the inshore and coastal fishing vessels. In order to keep the constant tension condition of warp under loading, a tension control circuit was added to the servo winch system.The dynamic performance in the open loop behaviour of the designed winch system was investigated and its applicability was tested for various possibilities of load using a load generator especially developed in order to this study.The mechanical characteristics of this system is different from that of a conventional type, that is, the tension, length, line speed and drum revolution can be automatically controlled by the information from various sensors, such as torque, rpm and pressure transducers. from the experiment results, it was verified that the servo winch system has very good output and tracking behaviour for the control input signals in different operating conditions though overshoot of out 8% in the transient characteristics of torque under the load though a overshoot of about 8% in the transient characteristics of torque under the load condition can be observed when the opening of servo valve, adjustable by the input voltage between - 10 V up to 10 V, changed suddenly.Consequently, the improved fishing winch system can be effectively used as the automatic shooting and hauling equipment of low cost for small inshore and coastal fishing vessels which engage in net fishing.

• 한국가스학회지
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• 제23권5호
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• pp.44-51
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• 2019

플랜트 안전훈련을 가상환경 하에서 진행하는 시스템을 구축하였을 때 고려해야 하는 시스템 구성요소와 구현 방법을 플랜트 특징에 따라서 구분하였다. VR기반의 안전훈련 시스템을 구성할 때 플랜트 특징에 따라서 필요한 구성요소가 다를 수 있으며, 대상 플랜트에 따라서 구축하는 기본적인 시스템 구성요소를 제시하였다. 제시하는 시스템의 구성을 뒷받침하기 위해서 비교적 간단한 설비인 도시가스 정압기 안전훈련 시스템을 구현하였고, 보다 복잡하고 큰 규모의 플랜트를 설명하기 위해서 석유화학 플랜트의 안전훈련 시스템 구현을 예로 들었다. 이를 통해서 적용하고자 하는 플랜트에서 적절한 VR 기반 플랜트 안전훈련 시스템 구성의 가이드라인을 제시한다.