• 한국조경학회지
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• 제29권2호
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• pp.61-67
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• 2001

The purpose of this thesis was to provide the basic data for landscape architecture of apartment constructions and to minimize the users´ and builder´ loss in terms of finance and landscape due to defects in planting. After a review of literature related to defects of planting work, the researcher investigated the defects in planting of landscape plants on the basis of data from the drawing and defect-repair construction of 50 civil apartment complexes in Daegu and Kyongbook are from 1994 to 1998. The defect-ratio was analysed in terms of the species, shapes, and sizes of trees. It provides matters for consideration in terms of the design of the landscape planting on the apartment unit. It also provided the future directions for landscape architecture in apartment constructions with regard to the selection of the planting trees, etc., given statistics on defect occurrence. The causes of defect of the landscape planting trees were not studied accurately in this study due to the board range of researched area, the differences of the planting ground environment, the management ability, and the parameters of judging planting defects. It is recommended that those areas should be researched in the future.

• Journal of Welding and Joining
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• 제14권2호
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• pp.90-95
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• 1996

In order to investigate characteristics of surface fatigue crack propagation from a pit shaped surface defect which frequently exists around welded joints, SS400 steel with thickness of 12mm, which has been generally used for structure members, was welded with submerged-arc butt type and machined for both surface. An initial surface defect of pit shape with the aspect ratio of 2 was made on the specimen. The initial defect was located at 5 different zones over the weldment : weld metal zone, boundary between weld metal and HAZ, HAZ, boundary between HAZ and base metal. Characteristics of surface fatigue crack propagation from the defect on each region under the same loading condition were investigated and compared.

• Journal of Advanced Marine Engineering and Technology
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• 제32권6호
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• pp.834-840
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• 2008

We carried out fatigue testing with materials of aluminum alloyC7075-T6, 2024-T4) by rotary bending fatigue tester. We investigated fatigue limit, fatigue crack initiation, fatigue crack propagation behavior and possibility of fatigue life prediction to the different small circular hole defect. The summarized result are as follows; Fatigue limit of the smooth specimens were related tensile strength and yield strength. In case of more large applied stress and small circular hole crack defect, the fatigue crack was grown rapidly. The fatigue crack propagation behavior proceed at according to inclusion. Fatigue crack propagation ratio appeared instability and retardation phenomenon in the first half of fatigue life but appeared stability and replied in the latter half. On other hand, this experimental data of the materials are appeared fatigue life predictability.

• Journal of Welding and Joining
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• 제7권3호
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• pp.36-43
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• 1989

The furnace brazing in a Ar of copper to martensitic stainless steel(13.5Cr) using Cu-(5~8%)P-(0~8%)Sn powders was investigated. Shear strength, wettability, reacted layer, defect ratio at the stainless steel interface was evaluated. As Sn was added to the Cu-P powders, defect ratio and P content at the stainless steel interface decreased. And also as Sn was added, defect form at the stainless steel interface changed from the continuous layer to the discrete type, and shear strength of the brazed joint increased.

• 디지털융복합연구
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• 제10권11호
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• pp.271-277
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• 2012

본 연구의 목적은 콘센트용 아크로 플레이트공정의 불량률을 줄이고 생산공정 개선을 통하여 생산성 향상시키는데 있다. 사출과정에서 사출시 온도와 압력에 대한 실험계획으로 최적의 조건을 찾아내고 아크로 플레이트 금형 개선을 하여 생산성을 향상시켰다. 본 연구에서는 사이클 타임은 70초에서 51초 줄었고 불량률은 20%에서 0.5%로 감소하였으며 생산원가 240원에서 201원으로 절감 효과를 가져왔다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.333-336
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• 2008

The groove rolling is a process that transforms the bloom or billet into a shape with circular section through a series of rolling. Inhibition of surface defect generation in groove rolling is a matter of great importance and therefore many research groups proposed a lot of models to find the location of surface defect initiation. In this study, we propose a model for maximum shear stress ratio over equivalent strain to catch the location of surface defect onset. This model is coupled with element removing method and applied to box groove rolling of POSCO No. 3 Rod Mill. Results show that proposed model in this study can find the location of surface defect initiation during groove rolling when finite element analysis results is compared with experiments. The proposed criterion has been applied successfully to design roll grooves which inhibits the generation of surface defect.

• 소성∙가공
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• 제17권8호
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• pp.607-612
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• 2008

The groove rolling is a process that transforms the bloom or billet into a shape with circular section through a series of rolling. Inhibition of surface defect generation in groove rolling is a matter of great importance and therefore many research groups proposed a lot of models to find the location of surface defect initiation. In this study, we propose a model for maximum shear stress ratio over equivalent strain to catch the location of surface defect onset. This model is coupled with element removing method and applied to box groove rolling of POSCO No.3 Rod Mill. Results show that proposed model in this study can find the location of surface defect initiation during groove rolling when finite element analysis results is compared with experiments. The proposed criterion has been applied successfully to design roll grooves which inhibit the generation of surface defect.

• 제어로봇시스템학회논문지
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• 제22권4호
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• pp.247-252
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• 2016

In this paper, we propose a new defect detection technology for micro-defect on the surface of steel products. Due to depth and size of microscopic defect, slop of surface and vibration of strip, the conventional optical method cannot guarantee the detection performance. To solve the above-mentioned problems and increase signal to noise ratio, a novel retro-schlieren method that consists of retro reflector and knife edge is proposed. Moreover dual switching lighting method is also applied to distinguish uneven micro defects and surface noise. In proposed method, defective regions are represented by a black and white pattern. This pattern is detected by a defect detection algorithm with Gabor filter. Experimental results by simulator for sample defects of cold rolled steel show that the proposed method is effective.

• KIEAE Journal
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• 제12권3호
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• pp.11-18
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• 2012

The purpose of this study is to contribute to solution of the defect dispute in apartment house in advance. We want to propose the improved devices in defect problems by investigating the money that exacted from the practical business of the inspection company and the money that a judge gave a decision in a civil court in 50 cases of the lawsuit to requesting the guarantee against defects and the improved schemes of the applied rate by analyzing the diagnosis money of each applied years about the term of warranty liability in 40 cases of the lawsuit separately from that. As the result, we have to reflect the defect of non construction and error construction on apartment building defects, which recognizes very important factor when we compute the defect repair warranty money and it needs to be rearranged the applied ratio in guarantee peried of housing law practically.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.852-862
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• 1996

This study was carried out to develop tools to detect defects of apple using machine vision. For the purpose, 6 kinds of frame for color images, R, G, B, h, S, and I frame, and a frame for near infra-red images (NIR frame) were tested first to select one which is useful to segment defect areas from apple images. After then, several methods to classify kind of defect for the segmented defect areas were developed and tested. Five kinds of apple defect -bruise , decay ,fleck worm hole and scar were investigated . The results are as follows: NIR frame was selected as the best one among the 7 kinds of image frame, and R, G and I frames showed favourable result to segment areas of apple defect. Various features of the segmented defect areas were measured to classify the defect areas. Eight kids of feature of the areas-size, roundness, axes length ratio, mean and variance of pixel values, variance of real part of spectrum, mean and variance of power spectrum resulted from spacial ourier transform were observed for the segmented defect areas in the selected 4 frames. then procedures to classify defects using the features were developed for the 4 frames and tested with 75-113 defects on apples. The test resulted that NIR and I frames showed high accuracies to classify the kind of defect as 77% and 76% , respectively.