• Clinical Endoscopy
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• 제57권1호
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• pp.82-88
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• 2024

Background/Aims: Guide tube-assisted endoscopy for procedures that require repeated endoscopic access is safer and more effective than conventional endoscopy. However, its effectiveness has not been confirmed in animal studies. We assessed the usefulness of guide tube-assisted endoscopic procedures in an in vivo porcine model. Methods: Five different guide tube-assisted endoscopic procedures were performed by experienced endoscopists on a pig weighing 32 kg. To evaluate the efficacy of these procedures, we compared the endoscopic approach time when a guide tube was used to that when it was not. Additional endoscopic procedures using a guide tube were performed, including multiple foreign body extractions, multiple polypectomies, and multiple submucosal dissections. To evaluate safety, we compared the insertion force into the proximal esophagus between the guide tube and conventional overtube methods. Results: Using the endoscopic approach with a guide tube required a shorter average approach time to reach the three target lesions than when using the endoscopic approach without a guide tube (p<0.001). Compared to the conventional overtube method, the guide tube method produced a lower average resistance during insertion into the upper esophagus (p<0.001). Conclusions: Guide tube-assisted endoscopic procedures are effective and safe for repeated endoscopic access in an in vivo porcine model.

• Communications for Statistical Applications and Methods
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• 제12권2호
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• pp.265-273
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• 2005

In this paper, we proposed multivariate EWMA control charts for both combine-accumulate and accumulate-combine approaches to monitor dispersion matrix of multiple quality variables. Numerical performance of the proposed charts are evaluated in terms of average run length(ARL). The performances show that small smoothing constants with accumulate-combine approach is preferred for detecting small shifts of the production process.

• Journal of the Korean Statistical Society
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• 제18권2호
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• pp.135-148
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• 1989

Cumulative sum schemes based on a weighted score are considered for controlling the mean of a continuous production process; in which both the one-sided and two-sided schemes are proposed. The average run lengths and the run length distributions for the proposed schemes are obtained by the Markov chain approach. Comparisons by the average run length show that the proposed schemes perform nearly as well as the standard cumulative sum schemes in detecting changes in the process mean. Comparisons of the one-sided schemes by the run length distribution are also presented.

• 한국운동역학회지
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• 제13권3호
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• pp.1-14
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• 2003

This study was conducted to investigate the principles and motions for increasing the jumping height of Fosbury Flop. The subjects were three male jumpers who were former Korean national team players. Their jumping motions were analyzed using the DLT method of three-dimensional cinematography. The conclusions were as follows. 1. The horizontal velocity of approach run and decreasing of this velocity during the take off phase were increased as the jumping height was increased. Therefore, in order to increase the jumping height, the horizontal velocity of approachrun should be increased and decreased properly during the take-off phase. The average height of the analyzed Dials was 2.15m. The average horizontal velocity of approachrun was 7.49m/s and decreased to 4.16m/s at the instance of take-off. 2. The vertical velocity of the center of gravity was increased as the ascending height of the center of gravity during the take-off phase was increased. Therefore, the center of gravity at the instant of touch down should be lowered. This could be possible by increasing the length of the last stride and the backward lean angle of the body. The average length of the last stride was 111.1% of the standing height, the average height of the center of gravity was 46.6% of the standing height and the average backward lean angle of the body was 40.3 degrees.

• 전기전자학회논문지
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• 제15권3호
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• pp.198-204
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• 2011

본 논문에서는 선택적 증폭후 전달(Opportunistic Amplify-and-Forward: OAF) 릴레이 시스템에 대한 새로운 성능 분석 기법을 레일리 페이딩 채널에 대하여 제안하였다. 제안된 분석 기법에서는 집합 연산(set-operation)을 기반으로 각 릴레이가 최적의 릴레이로 선택될 확률을 유도한다. 그리고 수신된 순시 신호 대 잡음비의 확률 밀도 함수를 기존의 분석 기법보다 일반적인 (확률밀도함수 표현에서 합 기호의 개수 및 그 영역이 구체화된)형태로 제시한다. 그리고 이를 이용하여 평균 오류율, 누락 확률 및 평균 채널 용량을 근사화된 닫혀진 형태로 유도한다. 제안된 성능분석 기법의 정확성은 모의실험을 통하여 검증한다. 성능분석 및 모의실험 결과 비교를 통하여 OAF 기법이 평균 오류 확률, 누락 확률 및 평균 채널 용량 측면에서 비선택적 기법에 비해 성능 향상 정도가 우수함을 확인한다.

• 대한산업공학회지
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• 제41권2호
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• pp.150-161
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• 2015

This paper proposes a new approach to technology valuation, the market-replacement cost approach which integrates the cost-based approach and market-based approach. The proposed approach estimates the market-replacement cost of a target technology using R&D costs of similar R&D projects previously conducted. Similar R&D projects are extracted from project database based on document similarity between project proposals and technology description of the target technology. R&D costs of similar R&D projects are adjusted by mirroring the rate of technological obsolescence and inflation. Market-replacement cost of the technology is then derived by calculating the weighted average of adjusted costs and similarity values of similar R&D projects. A case of "Prevention method and system for the diffusion of mobile malicious code" is presented to illustrate the proposed approach.

• 아동학회지
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• 제25권6호
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• pp.131-152
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• 2004

This study used meta-analysis to synthesize the effectiveness of the project approach. After reviewing 51 studies, we analyzed the effect size of 119 articles published between 1990 and 2002 using SAS 8.2 program. The grand average of the project approach effectiveness was 1.03. This implies that the experimental group that employing the project approach is more effective than control group by the 35 percentile. We also found that the project approach is more effective for preschool children group (1.21, 89%) than for the elementary school children group (0.88, 81%). Specific variables regarding the effectiveness of the project approach were analyzed and its consequences were discussed.

• 한국기계가공학회지
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• 제15권6호
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• pp.41-49
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• 2016

To evaluate lubrication properties by surface roughness under boundary and mixed lubrication, a new approach is suggested by both asperity flow and contact with stochastic characteristics. Many researchers already have studied the effect of surface roughness on flow. But, it has become important to research of the phenomenon of asperities contact in surfaces because the growth of asperities contact area under heavy load conditions. In this paper, flow factors in the average flow model derived by Patir and Cheng were used, and a multi-asperity contact model was included to calculate lubrication properties of a surface with a randomly generated rough surface. A numerical analysis using the average Reynolds equation with both the average flow model and the asperity contact model was conducted, and the results were compared with those from previous research. The results showed that the influence of asperities on lubrication and the friction coefficient changed rapidly on application of contact model.

• 대한임베디드공학회논문지
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• 제16권6호
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• pp.277-283
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• 2021

This paper addresses the problem of vision-based mask filter inspection for mask production systems. Machine learning-based approaches can be considered to solve the problem, but they may not be applicable to mask filter inspection if normal and anomaly mask filter data are not sufficient. In such cases, handcrafted image processing methods have to be considered to solve the problem. In this paper, we propose a hierarchical correlation-based approach that combines handcrafted image processing methods to detect anomaly mask filters. The proposed approach combines image rotation, cropping and resizing, edge detection of mask filter parts, average blurring, and correlation-based decision. The proposed approach was tested and analyzed with real mask filters. The results showed that the proposed approach was able to successfully detect anomalies in mask filters.

• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 1998년도 Language, Information and Computation = Selected Papers from the 12th Pacific Asia Conference on Language, Information and Computation, Singapore
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• pp.195-205
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• 1998