• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.51-52
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• 2011

본 연구에서는 전해 구리도금막과 SiN 피복층 사이의 힐락 (Hillock) 및 보이드 (Void) 결함에 미치는 전해 구리도금 공정 및 CVD SiN 피복층 증착 전 NH3 플라즈마 처리 효과에 대해 연구하였다. SiN 피복층 증착전 NH3 플라즈마 효과를 정량화하기 위해 실험계획법을 이용해 NH3 플라즈마 공정 인자가 힐락 결함의 밀도에 미치는 영향에 대해 고찰하였다. 실험결과, 힐락 결함의 밀도는 NH3 플라즈마 인가 시간에 비례한다는 것을 알았다. 보이드 결함의 경우, 구리 씨앗층 및 NH3 플라즈마 조건의 최적화를 통해 구리 씨앗층의 표면 조도를 최소화할 경우 보이드 결함이 최소화된다는 것을 알 수 있었다. 이는 구리 씨앗층의 표면 조도를 최소화함에 따라 전해 구리도금막의 결정립 크기가 커져 결정립 계면에 존재하는 불순물 양이 줄어들었기 때문인 것으로 사료된다.

• Annual Conference of KIPS
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• 2003.11c
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• pp.1633-1636
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• 2003

코드검증은 소프트웨어공학에서 제안한 개발 프로세스 상의 여러 절차 중 비용 대 효과 측면에서 가장 효과적이라고 알려져 있다. 그러나 코드검증 절차 도입 초기에는 적용에 따른 기대 수준이 낮으며, 추가 작업에 대한 개발자와 관리자의 부담이 높기 때문에 투입시간, 자원할당 등의 계획은 설득력 있는 근거를 바탕으로 체계적으로 수립되어야 한다. 본 논문에서는 기존 제품 개발 시 발생 되었던 결함의 원인 분석과 결함 제거에 투입된 공수 산출을 바탕으로 코드검증 절차를 개발 프로세스 상에 도입, 계획할 수 있는 방안을 제시한다.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1469-1471
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• 2006

It is very important to discriminate noises such as air corona in measuring on-site partial discharges (PD). Therefore, in order to investigate the possibility of separating PD(partial discharge) and noises through the pulse analysis, pulse shapes measured by a resistive sensor and a HFCT were analyzed and PA(pulse analysis) were performed. For the purpose, the HFPD detection and PA system has been developed. Also void discharges and air corona were adopted as the artificial defect and noises, respectively.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.215-216
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• 2006

To lower the cost of MIM products, the gate and runner materials and green parts with defects are usually recycled. It is necessary to understand what causes the recycled products to deteriorate. The results show that the viscosity of the 1R (recycled once) feedstock was slightly lower than that of the fresh material. However, as the number of recyclings increased, the viscosity increased, while the density decreased, and more defects were noticed duri ng solvent debinding. These deteriorations were mainly caused by the increase of the melting point of the backbone binder and the oxidation of the filler or paraffin wax.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.1
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• pp.1-6
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• 2017

Total capacity of pumped hydro storage(PHS) in Korean power system reaches 4,700MW, though the share of it is about 4.56% of total capacity The Unit Commitment program, E-terracommit which is used for the operational purpose by KPX, includes the PHS model. But the model has a defect that it does not include the information of water level of upper reservoir. Therefore two types of improved the PHS models are represented in this paper. The first model is a optimized model by connecting the upper reservoir water level to the non-spinning reserve. The other model is to have priority allocate both the PHS and combined cycle generator for non-spinning reserve. The proposed two models and the E-terracommit model is compared and resulting to have improvement in estimating non-spinning reserve when using the proposed models.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.4
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• pp.803-808
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• 2000

This paper presents development of a different substance monitoring system base reliable detection between the conveyer belt and hopper used for materials transport line of steel company. Conventional detection method of a piece of iron separation system is losed the confidence, because of the place with bad surroundings of measurement so much that materials production line are completely exposed to dust, moisture and vibration. For the solution of this problem, we developed a different substance detection system using the acoustic emittion sensor and one chip microprocessor which is available for bad surroundings and inexpensive. The reliability of the system was estimated by experiment.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.942-944
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• 2005

In this study, eddy current signals from various anomalous defects in the heat exchanger tube are predicted af their signal slope characteristics no analyzed. The signal changes due to frequency increase are also observed. Based in the accumulated knowledge, the analysis of superimposed signal is attempted which includes the effects of support plate. Both differential and absolute bobbin probe signals are analyzed. For the prediction of signals, axisymmetric finite element modeling is used and this leads us to the utilization of slope angle analysis of the signal. Results show that differential signals are useful to locate the position of defect under the support plate and absolute signals no easy to predict and analyze even though they no superimposed signals. Combined use of these two types of signals will accomplish a reliable inspection.

• Nuclear Engineering and Technology
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• v.45 no.3
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• pp.361-366
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• 2013

An imaging technique to visualize the internal defects in a plate-type nuclear fuel specimen was developed by using an active optical interferometer for a nondestructive quality inspection. A periodic thermal wave having a sinusoidal intensity pattern induced a periodical strain variation for the specimen. The varying strain image was acquired using an optical laser interferometer. The strain distribution over the internal defects will be distorted in an acquired strain image because a part of the thermal wave will be reflected from these defects during propagation. In this paper, internal defects were efficiently visualized by sequentially accumulating the extracted defect components. The experimental results confirmed that the developed visualization system can be a valuable tool to detect the internal defects in plate-type nuclear fuel.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.381-391
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• 2006

When the environmental materials of the raw and sub material to applied in electronic goods removed, the reliability assessment and the forecasting is stand on the low level and in case of neglect, it is acting as latent defect that can be connected to large size disaster. In this research, the study on the management method of environmental restriction substances which is recognized as important element in the reliability assessment about environmental material of electronic goods and the study on reliability assessment method of PWB without environmental material are progressed

• Journal of the Korean Society for Precision Engineering
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• v.20 no.3
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• pp.82-88
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• 2003

The nondestructive internal quality evaluation of agricultural products has been strongly required from the needs for individual inspection. Recently, the ultrasonic wave has been considered as a solution fur this problem, and an ultrasonic system was constructed for the ultrasonic NDE of fruits and vegetables in our previous work. In this paper, the practical applicability of our ultrasonic system is tested fur the inspection of internal defects (central cavity) in Atlantic potato. Sound speed and RMS of transmitted ultrasonic wave signal were measured and classification algorithm using 2 dimensional stochastic analysis. was presented. Experimental results showed greater value of sound speed and RMS (root mean square) of transmitted signal in normal samples than in abnormal samples with cavity. Also a stochastic method to distinguish normal and abnormal showed fault detection rate less than 5%.