• 한국의류학회지
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• 제1권2호
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• pp.81-88
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• 1977

In order to investigate seam puckering in thin fabrics for summer clothing, this experiment was conducted. Eight different fabrics were sewn with ten different kinds of sewing thread, three different sizes of stitch, and three sewing directions and effects on puckering were examined. The results are as follows: 1. More seam puckering appears on thin fabrics than on thick ones. 2. Less seam puckering appears with the smaller sizes of stitch. 3. Slant direction of sewing gets less seam puckering. 4. Almost no puckering appears with slant direction even after washing.

• 한국의류학회지
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• 제23권1호
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• pp.66-77
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• 1999

For this study It was measured the seam puckering based on the mechanical properties of tencel under the proper condition of needlework and machine sewing analyzed the mechanical properties which re influenced to the seam puckering and estimated the seam puckering based on the mechanical properties. The results of this study are as follows : There are three types of the seam puckering for each step which is caused by repeated washing and press. Concerning the seam puckering with the number of washing the more the number of washing is increased the less the seam puckering is decreased. Concerning the mecanical properties of the sample with the seam puckering. The seam puckering is related to LT positively B, 2HB, T, W negatively Among the mechanical properties LT, B, 2HB, T, W are most influenced to the seam puckering. Judging from the result of estimating seam puckering based on mechanical properties the estimate-formula is satisfied in this study.

• 한국생활환경학회지
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• 제24권4호
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• pp.533-540
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• 2017

This study analyzes the stretchability and clothing pressure of fabrics made from stretchy knit materials, and uses the baseline data to develop various functional clothing made from stretchy knit fabrics. To observe the changes in the stretchability and clothing pressure, we observed the compatibility of the two materials (tricot and power-net), presence of flat seam, fabric layering, and flat seam direction as key variables. A standard test method for stretch properties (ASTM D2594) was used for measuring the stretchability of the material. Clothing pressure measurements were analyzed in terms of the mean and standard deviation values, and the correlation of the stretchability. In the case of tricot, the presence of flat seam increased the stretchability of the fabric regardless of the fabric layering. However, when tricot and the less stretchable power-net were combined, the presence of flat seam did not increase the stretchability. Flat seam did not interfere with or limit the stretchability of the fabric, but they did increase the clothing pressure at the seam. The stretchability had a negative correlation with the clothing pressure except along the flat seam.

• International Journal of Korean Welding Society
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• 제2권2호
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• pp.51-56
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• 2002

The weld seam tracking system for arc welding process uses various kinds of sensors such as arc sensor, vision sensor, laser displacement sensor and so on. Among the variety of sensors available, electro-magnetic sensor is one of the most useful methods especially in sheet metal butt-joint arc welding, primarily because it is hardly affected by the intense arc light and fume generated during the welding process, and also by the surface condition of weldments. In this study, a dual-electromagnetic sensor, which utilizes the induced current variation in the sensing coil due to the eddy current variation of the metal near the sensor, was developed for arc welding of sheet metal I-butt joints. The dual-electromagnetic sensor thus detects the offset displacement of weld line from the center of sensor head even though there's no clearance in the joint. A set of design variables of the sensor was determined far the maximum sensing capability through the repeated experiments. Seam tracking is performed by correcting the position of sensor to the amount of offset displacement every sampling period. From the experimental results, the developed sensor showed the excellent capability of weld seam detection when the sensor to workpiece distance is near less than 5 ㎜, and it was revealed that the system has excellent seam tracking ability for the I-butt joint of sheet metal.

• Journal of Welding and Joining
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• 제18권4호
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• pp.70-75
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• 2000

The weld seam tracking system for arc welding process uses various kinds of sensors such as arc sensor, vision sensor, laser displacement and so on. Among the variety of sensors available, electro-magnetic sensor is one of the most useful methods especially in sheet metal butt-joint arc welding, primarily because it is hardly affected by the intense arc light and fume generated during the welding process, and also by the surface condition of weldments. In this study, a dual-electromagnetic sensor, which utilizes the induced current variation in the sensing coil due to the eddy current variation of the metal near the sensor, was developed for arc welding of sheet metal butt-joints. The dual-electromagnetic sensor thus detects the offset displacement of weld line from the center of sensor head even though there's no clearance in the joint. A set of design variables of the sensor were determined for the maximum sensing capability through the repeated experiments. Seam tracking is performed by correcting the position of sensor to the amount of offset displacement every sampling period. From the experimental results, the developed sensor showed the excellent capability of weld seam detection when the sensor to workpiece distance is near less than 5 mm, and it was revealed that the system has excellent seam tracking ability for the butt-joint of sheet metal.

• 반도체디스플레이기술학회지
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• 제14권3호
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• pp.23-26
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• 2015

A seam carving based micro-crack detection method is proposed which aims at detecting the micro-crack regions in heterogeneously textured surface of polycrystalline solar cells. By calculating the seam which is a connected path of low energy pixels in the image, the micro-crack regions can be detected. Experimental results show that the proposed seam carving based micro-crack detection method has superior efficiency in detecting the micro-crack without background noise pixels and the algorithm's computation time is less than the conventional algorithm.

• Journal of Welding and Joining
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• 제19권1호
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• pp.27-32
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• 2001

This paper is studied about welding conditions and weldability of seam welding for galvanized steel sheet of automotive. The fuel tank of automobile is made by seam welding to be required of airtight or oiltight. This method have required a short time for welding, simplicity operation progress and little HAZ. Especially, it has more less residual stress and transformation than different welding progress. So, this study is for decreasing the leakage occurrence rate and to make standard operating condition table anyone can operate easily. Therefore, this study is analyzed the optimum conditions of seam welding for making the automobile with galvanized steel sheets by means of observing the microstructure and configuration back projection, RT, tensile-shear strengths test and SEM. Optimum conditions of seam welding obtained as follows, current 17.2-17.6kA speed 1.0m/min weld time 4:10:6 and current 16.5-17.4kA, speed 0.83m/min, weld time 4:10:4 at t1.0, and current, 18.5-18.9kA, speed 0.8m/min, weld time 4:10:4 and current 16.5-17.4kA, speed 0.68m/mi, weld time 4:10:2 at t1.6.

• Journal of Welding and Joining
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• 제15권5호
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• pp.74-83
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• 1997

Effect of welding parameters such as current, speed and electrode pressure on the weld quality of tin coated steels for small containers was discussed in this paper. Welding was performed with low frequency wire seam welding system which was loaded with 1.5mm in diameter copper wire electrode. The welding parameters were monitored at the position close to the welding spot so as to minimize the instrumentation error, and the signals were stored into a digital data acquisition system before analysis. Results showed that critical current for sufficient nugget size increased as the base material thickness increased, while the width of the optimum welding range was reduced. The acceptable welding condition derived from this study was found to be effective within the thickness range of $\pm$10% of the nominal (0.25mm) thickness. Tin coating layer was proved not to affect seriously on the weld quality, i.e. strength and formability, since consumable wire electrode was used in this process. Test results also demonstrated that the welding current was thought to be the most effective parameter to form an acceptable weld, while welding speed or electrode pressure exerted less effect on the nugget formation. However, these two parameters played an important role because the former was related to the nugget overlap interval, and the latter, to the formation of expulsion during welding.

• 한국공간구조학회논문집
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• 제12권1호
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• pp.109-119
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• 2012

막 구조물은 일반적인 설계와는 달리 형상해석, 응력변형해석 및 재단도 과정을 수행하여야만 설계가 가능하다. 처음 두 과정과는 달리 재단은 3차원 곡면을 최소 오차를 가진 평면 스트립을 형성하는 과정이다. 경제적인 이유로 재단 선은 주로 측지선을 이용하여 작성된다. 그러나 일반적으로 측지선은 초기 형상탐색에서 구성된 삼각형 요소의 정보에서 추출됨으로 부드러운 곡선이 아니며, 불규칙한 직선이다. 그러므로 어떻게 불규칙한 직선을 곡선으로 표현할 것인가가 중요하다. 따라서 본 연구에서는 스플라인 함수를 이용한 보간 방법을 재단도 생성에 적용하였다. 이를 위해서 삼차 스플라인 함수, B-스플라인 함수 및 최소자승 스플라인 함수의 세 가지 경우에 대해서 고찰하고, 단순 모델 및 카테나리 모델을 대상으로 재단도 작성 결과를 검토하였다. 단순모델의 해석요소수와 추출된 불연속 절점 수에 따른 보간 곡선 비교결과는 요소수가 큰 경우 추출된 절점의 수가 적은 것이 효과적이며, 최소자승 보간이 다른 방법보다 더 부드러운 재단 경계선을 제공한다.

• 한국철도학회논문집
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• 제5권4호
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• pp.237-243
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• 2002

Now operating lines of many urban railway are currently in progress in the Seoul, but the inadequate consideration of links between different lines could create inconvenience as the public transport. This paper is studied about the connection service design of urban-railway convinced for other metropolis railways forms and propose the base pilot plan of the railway network linking system in Seoul Metropolis.