• 한국지반공학회논문집
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• 제23권11호
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• pp.99-107
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• 2007

Hvorslev법이나 Bouwer and Rice법과 같은 선형 커브피팅법은 대수층의 현장 투수계수를 구하기 위해 실시하는 순간변위시험 혹은 순간충격시험(slug test) 결과를 효과적이고 간편하게 해석하도록 한다. 그러나, 대수층의 압축성이 클 경우, 순간변위시험의 결과가 반대수 그래프에서 선형적이지 않고 상향으로 오목한 곡선 형태를 갖게 되므로, 대수층의 압축성을 무시하는 기존의 선형 커브피팅법은 이런 경우에 그대로 적용하기 어렵다. 본 논문에서는 두 선형 커브피팅법을 부분 관통된 우물의 경우에 대하여 비교 분석하여 대부분의 경우에 Hvorslev법이 Bouwer and Rice법에 비하여 과다하게 현장 투수계수를 산정함을 보였다. 또한, 각기 다른 커브피팅 방법에 따른 순간변위시험 해석결과를 무차원 압축 매게변수(${\alpha}$)의 범위 0.001에서 1까지에 대하여 비교 분석하였다. 마지막으로, 압축성이 큰 대수층의 순간 변위시험 해석을 위하여 Chirlin의 방법을 부분 관통된 우물의 형상을 고려할 수 있도록 확장하여 수정된 선형 커브피팅법을 제시하였다. 제안된 방법의 현장 적용성을 검토하기 위해 빙적토 대수층에서 실시된 순간 변위시험 결과를 이용하여 사례분석을 하였다.

• 대한의용생체공학회:의공학회지
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• 제30권2호
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• pp.169-178
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• 2009

In this study, we suggest Korean nonlinear fitting formula (KNFF) to maximize speech intelligibility for digital hearing aids based on NAL-NL1 (NAL-nonlinear, version 1). KNFF was derived from the same procedure which is used for deriving NAL-NL1. KNFF consider the long-term average speech spectrum of Korean instead of English because the frequency characteristic of Korean is different from that of English. New insertion gains of KNFF were derived using the SII (speech intelligibility index) program provided by ANSI. In addition, the insertion gains were modified to maximize the intelligibility of high frequency words. To verify effect of the new fitting gain, we performed speech discrimination test (SDT) and preference test using the hearing loss simulator from NOISH. In the SDT, a word set as test material consists of 50 1-syllable word generally used in hearing clinic. As a result of the test, in case of moderate hearing loss with severe loss on high frequency, the SDT scores of KNFF was more improved about 3.2% than NAL-NLl and about 6% in case of the sever hearing loss. Finally we have obtained the result that it was the effective way to increase gain of mid-high frequency bands and to decrease gain of low frequency bands in order to maximize speech intelligibility of Korean.

• 한국멀티미디어학회논문지
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• 제12권1호
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• pp.50-57
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• 2009

본 논문은 3차원 다각형 모델에서 특징 선을 추출하기 위한 방법에 대해 제안한다. 이산 곡면으로 이루어진 다각형 모델에서 특징 선을 추출하기 위하여 기존 방법에서는 전역적인 음함수 곡면 맞춤 기법(Implicit Surface Fitting)을 이용하여 모델의 꼭지점에서 곡률과 곡률 미분 값을 측정하였다. 이러한 방법은 다각형 모델의 꼭지점에서 음함수 곡면으로 정확하게 투영할 수 있도록 사용자의 정의 파라미타를 찾아야 하며, 특징 추출을 위한 많은 계산 시간을 요구한다. 그러나 제안 방법은 지역적 음함수 곡면 맞춤 기법을 이용하여 모델의 꼭지점에 근사된 곡면을 통해 미분 정보를 측정한다. 측정된 미분 정보를 통해 쉽게 각각의 모서리에서 제로-클로싱을 통해 특징 점을 추출하고, 곡률 방향을 따라 추출된 점들을 연결하여 특징 선을 생성한다. 여러 가지 다각형 모델에서 실험을 하였고 기존 방법보다 빠르며 높은 품질의 특징 선을 추출한다.

• 한국의류산업학회지
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• 제17권3호
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• pp.421-428
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• 2015

This research is to understand customer satisfaction with virtual fitting based on a 3D body scanner and avatars as well as differences between avatars and the 'real me'. To this end, this research examined Korean college students to facilitate 3D body scanning, avatar generation and surveys. The author used 3D body scan data with direct measurements to identify differences between the 3D body scan data-based 'my avatar' and 'real me' in the virtual dress fitting system. The survey results on 'the level of customer awareness on 3D body scanner' found that the majority of both genders did not know about it and indicated a lower usability to incorporate IT technology into the fashion industry. The question in the 3D body scanning and avatar found an affirmative attitude. Satisfaction levels on the 3D avatars' similarity with 'own body' and garment fitting were positive and indicated a need for further technological improvements to express the avatars identical to customers' own body. More research is necessary for the accuracy of sizes for 3D body scanning that measure body sizes while wearing clothes. Avatars based on such datamay be less similar to 'own body' and cause customer dissatisfaction. Thus, further technology development is required to narrow gaps using data to make avatars that provide more accurate virtual fitting simulation services to customers.

• 한국CDE학회논문집
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• 제20권4호
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• pp.375-384
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• 2015

Recently, there has been a gradual increase in the number of people who are interested in cycling, leading to an increasing number of cycling equipment consumers. However, many bicyclists get hurt because of their lack of knowledge about the right size of bicycle for their body. Although it is necessary for a rider to fit their bicycle to prevent injury, they reject a fitting service because of the long hours and high cost. In this study, we propose a bicycle fitting system that uses a depth camera to improve the limitations of existing manual fitting systems. With the defined formula, the system calculates the size of the bicycle using body image information extracted by a depth camera and visualizes a customized bicycle for a specific consumer. This system will not only save the customer time and money, but will prevent injury from the use of a bicycle that does not fit.

• 센서학회지
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• 제26권4호
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• pp.259-265
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• 2017

Magnetometer calibration must be performed before the use of three-axis magnetometers to ensure the accuracy of orientation estimation. Recently, one of the most popular calibration approaches is the ellipsoid fitting technique due to its high performance in calibration. To date, in fact, performances of the existing ellipsoid fitting methods have been evaluated with full range rotation data. However, in case of the calibration of magnetometers attached to vehicles, ships, and planes, it is very difficult to collect the full range rotation data since their allowable ranges in terms of roll and pitch are limited to small. This constraint may result in serious performance degradation of some ellipsoid fitting algorithms. Therefore, to be practical, this paper proposes a weighted least square-based magnetometer calibration method that is robust in roll-pitch limited conditions. Furthermore, the proposed method is a linear approach and thus is free from the well-known initial value issue in nonlinear approaches. Experimental results show the superiority of the proposed method to other ellipsoid-fitting calibration methods.

• 소성∙가공
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• 제27권1호
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• pp.54-59
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• 2018

In connecting parts of a hydrogen fuel cell vehicle, since the rubber ring is permeable to hydrogen, it is necessary to use a metal sealing structure which ensures leakage stability. Finite element analysis was performed to verify the fitting characteristics of the metal sealing structure, which is used to connect the pipe to a high pressure hydrogen FCEV tank. Deformation shape, contact distance and axial load were compared experimentally and these values were in agreement with each other. In the contact surface, between the pipe and the fitting body, the stress at the edge of the contact surface was higher than the center point, which was considered to be a good characteristic in view point of the leakage. The location of the contact points has almost no change in the upper part of the fitting, but that of the lower parts move downward as the fastening amount increases. The contact pressure at the lower part is maintained at the same constant level.

• 한국음향학회지
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• 제31권5호
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• pp.273-279
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• 2012

본 논문에서는 64채널 디지털 보청기의 주파수 채널 별 비선형 압축을 위한 휘팅 기법을 연구하였다. 청력 검사 결과로부터 수행되는 기존의 휘팅 포뮬라 기법과 달리, 귓속형 보청기를 사용자가 외이도에 착용한 상태에서 고막에서의 청력 역치를 측정하여 이를 휘팅에 적용하였다. 또한 외부 음성 음압의 주파수 별 분포도를 활용하여 입력 음압 대비 출력 음압 압축 곡선을 구현하였다. FFT-iFFT 방식의 이론적 압축 연구 결과를 실험적으로도 검증하였으며, 입력음압 레벨이 각각 50 dB, 70 dB, 90 dB일 때의 증폭 이득 곡선을 보여주었다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 추계학술대회
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• pp.410-413
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• 2009

웨이퍼 Pre-Alignment는 반도체 공정에서 장비에 웨이퍼를 놓기 전에 웨이퍼의 중심 및 방향을 정확하게 정렬할 필요가 있는데, 이를 위해서 일정한 수준 이하로 중심과 방향을 찾아 Alignment 하는 방법을 말한다. 본 논문에서는 웨이퍼를 Alignment 하기 위해 기존의 Mechanical한 방법이 아닌 Area 카메라를 통한 비접촉식 방법을 이용하였다. 이 방법은 웨이퍼를 45도씩 8번씩, 한 바퀴를 회전하여 이미지를 획득한 뒤, 이미지의 웨이퍼의 에지값 들을 이용하여 Least Square Circle Fitting을 이용하여 웨이퍼의 중심과 방향을 정확하게 측정하여 Alignment를 한다.

• 한국임상보건과학회지
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• 제9권1호
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• pp.1462-1468
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• 2021

Purpose; The purpose of this study is to objectively identify and quantify the wearer's feelings of wearing glasses. Methods: The temperature of the skin on the nose ridges and ear, and the area where the glasses were seated, was measured using a thermal imaging camera. Results: Before wearing the glasses, the temperature of the skin surface on the nasal ridge was 34.908 ± 0.875 ℃ and the temperature of the ear region was determined as 31.981 ± 0.549 ℃. The changed temperature measured at 5 minutes later after taking off the glasses showed that the nasal ridge was determined as 35.467 ± 0.342 ℃ and the ear area was determined as 32.994 ± 0.412 ℃ (p<0.05). Conclusions: In this experiment, it was revealed that the glasses cause discomfort and heat in the fitting area. It was the first attempt to study objectively and scientifically. Analysis of frame fitting points by using thermal camera is expected to be helpful when consulting a sensitive person about changes in the fit of glasses.