• 한국압력기기공학회 논문집
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• 제6권1호
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• pp.72-77
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• 2010

During the period of reinforcement work for the licensing renewal of CANDU NPP, the fuel channels, Calandria tubes and feeders of CANDU Reactor are replaced. The remote visual inspection of Calandria internal is also performed during the period of reinforcement work. This period is a unique opportunity to inspect the inside of the Calandria. The visual inspection for the Calandria vessel and its internals of Wolsong NPP Unit 1 was performed by Nuclear Engineering & Technology Institute(NETEC) of KHNP. To perform this inspection, NETEC developed equipment applied new technology such as the synchronization of 3D CAD, automatic alignment and control system. The inspection confirmed that the Calandria integrity of Wolsong NPP Unit 1 is perfect.

• 대한기계학회논문집A
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• 제28권6호
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• pp.867-875
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• 2004

In order to inspect burr geometry and hole quality in micro-drilling processes, a cost-effective method using an image processing and shape from focus (SFF) methods on the machine tool is proposed. A CCD camera with a zoom lens and a novel illumination unit is used in this paper. Since the on-machine vision unit is incorporated with the CNC function of the machine tool, direct measurement and condition monitoring of micro-drilling processes are conducted between drilling processes on the machine tool. Stainless steel and hardened tool steel are used as specimens, as well as twist drills made of carbide are used in experiments. Validity of the developed system is confirmed through experiments.

• 환경위생공학
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• 제16권2호
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• pp.17-23
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• 2001

The objective of this study was to investigate the component ratio of gas generated at closed GD landfill site in MY city and the decomposition status of landfill gas, and was to examine and analyze the properties of the landfill gas. In addition, to provide basic data required to stabilize landfill earlier in the future, the study was to measure gas by landfill gas gauge and to analyze the properties of landfill gas based on documents. As a result of analyzing the properties, acquired follow results. 1. The main elements of landfill gas, $CH_4$ and $CO_2$ were respectively 25.02% and 22.325 on the average. 2. $NH_3$ and $H_2S$ were respectively 1.07 4.97 and 0.75 1.15 on the average. 3. Generated gas was different depending on water, pH properties of MSW(Munticipal Solid Wastes) and their decomposition rate. Furthermore, when measured the temperature of room to inspect landfill gas, the temperature was $22{\;}-{\;}30^{\circ}C$ in the average.

• 한국철도학회논문집
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• 제11권2호
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• pp.115-119
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• 2008

고속선에서의 궤도틀림은 차량의 주행 안정성 및 소음, 진동 등에 큰 영향을 끼치는 요소이다. 차량의 흔들림을 억제하고 효율적인 선로의 점검 및 관리를 위해서는 정확하고, 고속의 궤도검측기구가 요구되고 있는 실정이다. 본 논문에서는 국내 기술로 제작된 한국형고속열차에 고속 궤도검측시스템을 구축하고, 시운전 시험을 통하여 검측된 궤도 검측 결과를 검토하고자 한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.951-954
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• 1998

This paper describes the implementation of the machine vision system and the method of classifying the objects. Its system described in this paper is consisted of robot, conveyer system, warehouse, and machine vision. This system first recognizes the object on conveyer, and then robot moves it to the warehouse. The position of the object on conveyer is always not constant, because it is not easy to extract the feature of its object and classify it into one of several categories. In this paper, to classify or inspect the pattern of the object, we propose the method of template matching using feature vector such as position invariant moment and mophological operation such as opening and closing. And we indentified an unregistered object using unsuperviser learning method and assigned it to the new pattern. We implemented its system and obtained satisfied results.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2001년도 정기학술대회
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• pp.239-244
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• 2001

Today, Ultrasonic is used as an important non-destructive test tool of semiconductor reliability evaluation and failure analysis. The semiconductor packaging trend goes to develop thin package, this trend makes difficult to inspect to defect in semiconductor package. One of the important problem in all semiconductor is moisture absorption in the atmosphere. This moisture causes crack or delamination to package when the semiconductor package is soldered on PCB. Reliability evaluation of semiconductor's object is investigating the effect of this moisture. For that reason, this study is investigating the effect of this moisture and reliability evaluation of semiconductor after preconditioning test and scanning acoustic microscope.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.791-794
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• 1999

Exact estimation of cement content in a hardened concrete can provide useful data to evaluate the quality and strength of the concrete and might be used to inspect the quality of precast concrete secondary products. Observation obtained in this research included : (1) the volume of coarse aggregate in the hardened concrete measured by the area comparison method has a high accuracy ; (2) the cement content in the mortar and the X-ray intensity of Ca-K$\alpha$ have a correlation factor of 0.96 ; (3) the cement content in the ready mixed concrete was estimated with high accuracy such as correlation factor of 0.99 and standard deviation of 0.64.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
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• pp.39-43
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• 2002

As the concept of the smart structure, monitoring of acoustic emission (AE) can be applied to inspect the fracture of the entire structure in operating condition using built-in sensors. The objective of this study is to find the characteristics of matrix crack signals in composites due to the different specimen shapes. To detect matrix crack signals, we performed tensile tests by changing the thickness, width and length of the specimen. For the quantitative evaluation, time frequency analysis such as short-time Fourier transform (STFT) was used to characterize the matrix crack signals from PZT sensor. The experimental result shows the distinctive signal features in frequency domain due to the different specimen shapes.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.394-399
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• 2004

Increased cumulative running times of railroad vehicle brings out such degradation as wear and fatigue. It don't adapt corrective maintenance which repairs a poor pan after a trouble but use preventive maintenance which fixes a bad part before a trouble. There were a few researches for preventive maintenance such as inspect affairs and facilities management. They couldn't estimate the operation reliability on railroad vehicle. Therefore, this study proposes the preventive maintenance procedure that predict repair period of end beam for uncovered freight car using reliability function and instantaneous failure rate on the basis of fatigue test and load history data.

• 한국공작기계학회논문집
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• 제13권3호
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• pp.84-90
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• 2004

Today, automobile world market is highly competitive. In order to strengthen the competitiveness, quality of automobile is recognized as important and efforts are being made to improve the quality of manufactured components. The directional ability of automobile has influence on driver directly and hence it must be solved on the preferential basis. In the present research, an automated vision system has been developed to inspect the front chassis module. To interpret the inspection data obtained for front chassis module, new interpreting algorithm have been developed. Previously the control of tolerance of front chassis module was done manually. With the help of the new algorithm developed, the dimension is calculated automatically to check whether the front chassis module is within the tolerance limit or not.