• Investigative Magnetic Resonance Imaging
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• 제1권1호
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• pp.154-161
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• 1997

목적: 횡격막 파열은 그 진단이 어렵고 지연되는 경우가 많으며, 진단이 늦어지면 유병율과 사망율이 높아지므로 조기진다는 매우 중요하다. 저자들은 최근 많이 이용되는 영상진단법인 나선형 CT와 자기공명영상, 그리고 초음파건사중 어떤 방법이 가장 예민하고 정확한 진단방법인지 동물실험 모델을 통하여 평가하고자 하였다. 대상 및 방법: 토끼에서 인위적으로 횡격막파열을 대, 중, 소로 만든 후 1일, 3일, 7일째 나선형 CT와 자기공명영상, 그리고 초음파검사를 동시에 시행하였다. 결과: 횡격막파열의 진단 민감도와 특이도는 초음파검사가 94.4%와 92.9%, 자기 공명영상이 54.0%와 85.75, 나선형 CT가 46.0%와 78.6%이었다. 횡격막 파열의 진단은 초음파검사, 자기공명영상, 나선형 CT순으로 정확하였으며 초음파 검사가 자기공명영상이나 나선형 CT보다 유의하게 우월하였고(P<0.05), 자기공명영상과 나선형 CT는 유의한 차이가 없었다. 초음파검사는 파열의 크기와 상관없이 횡격막파열의 구별이 용이하였고 자기공명영상과 나선형 CT는 파열의 크기가 클수록 횡격막파열의 구별이 용이하였으나 통계적으로 유의한 차이는 없었다(P>0.05). 수술후 1일에는 전예에서 늑막삼출액이나 혈흉을 동반하였다. 이때에는 초음파나 자기공명영상이 나선형 CT에 비해 우월하였다. 시간경과에 따랄 초음파검사와 자기공명영상은 진단율이 상대적으로 저하되었으나 통게적으로 유의한 차이는 없었다(P>0.05) 탈장을 동반한 경우에는 진단의 민감도가 자기공명영상, 나선형 CT, 초음파검사순으로 높았으며 초음파검사가 상대적으로 낮았다. 그러나 통계적으로 유의한 차이는 없었다(P>0.05). 결론: 초음파검사가 횡격막파열의 진단에 가장 유용한 것으로 밝혀졌으며, 이러한 결과는 앞으로 임상에 적용하여 검증되어야 할 필요가 있다고 생각된다.

• 한국대기환경학회지
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• 제33권6호
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• pp.583-592
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• 2017

A method is proposed for locating the heat sources from temperature observations, and its applicability is investigated for urban thermal environment simulations. A Lagrangian particle dispersion model, which is originally built for simulating the pollutants spread in the air, is exploited to identify the heat sources by transporting the Lagrangian heat particles backwards in time. The urban wind fields are estimated using a diagnostic meteorological model incorporating the morphological model for the urban canopy. The proposed method is tested for the horizontally homogeneous urban boundary layer problems. The effects of the turbulence levels and the computational time on the simulation are investigated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.442-445
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• 1997

A challenging activity in the manufacturing industry is to perform in real time the continuous monitoring of the process state, the situation assessment and identification of the problem on line and diagnosis of the cause and importance of the problem if he process does not work properly. This paper describes LAT(Ladder Analysis Tool) system for fault tree generation to improving the fault diagnosis of CNC machine tools. The system consists of 4 steps which can automatically ladder analysis from ladder diagram to two diagnosis function models. The two diagnostic models based on he ladder diagram is switching function model and step switching function model. This system tries to overcome diagnosis deficiencies present machine tool.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.601-606
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• 2004

This paper deals with friction-induced vibration of disc brake system under constant friction coefficient. A linear, lumped and distributed parameter model to represent the floating caliper disc brake system is proposed. The complex eigenvalues are used to investigate the dynamic stability and in order to verify simulations which are based on the theoretical model, the experimental modal test and the dynamometer test are performed. The comparison of experimental and theoretical results shows a good agreement and the analysis indicates that mode coupling due to friction force is responsible for disc brake squeal. And squeal type instability is investigated by using the parametric analysis. This indicates parameters which have influence on the propensity of brake squeal. This helped to validate the analysis model and establish confidence in the analysis results. Also they may be useful during system development or diagnostic analysis.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.172-176
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• 2000

A series of preliminary experiments were carried out to quantify the annoyance are noisiness caused by floor impact noise. From the results of the experiments. the heavy impact source was found to be felt louder and noisier than the light impact source. Measurements of noise were also conducted by a diagnostic system based on the model(the model consists of the autocorrelators and the cross-correlation for signals arriving at two ear entrants) of the human auditory-brain system. Physical factors in the model were calculated by use of the ACF(autocorrelation function) and IACF(interaural cross correlation function) of binaural signals. From the ACF/IACF analysis, it was found that perceived loudness of floor impact noise could be represented by the factors of the ACF/IACF model.

• 환경영향평가
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• 제11권2호
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• pp.109-116
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• 2002

The diagnostic and prognostic methods for generating 3 dimensional wind field were comparatively analyzed and 4 dimensional data assimilation (FDDA) technique by incorporating Automatic Weather System (AWS) into the prognostic methods was discussed for the urban scale air quality model. The A WS covered the urban scale grid distance of 10.6 km and 4.3 km in South Korea and Kyong-in region, respectively. This is representing that AWS for FDDA could be fairly well accommodated in prognostic model with the meso${\gamma}$~ microa scale (~5 km), indicating that the 3 dimensional wind field by FDDA technique could be a useful interpretative tool in urban area for the atmospheric environmental impact assessment.

• 한국소음진동공학회논문집
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• 제14권8호
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• pp.702-708
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• 2004

This paper deals with friction-induced vibration of disc brake system under constant friction coefficient. A linear, lumped and distributed parameter model to represent the floating caliper disc brake system is proposed. The complex eigenvalues are used to investigate the dynamic stability and in order to verify simulations which are based on the theoretical model, the experimental modal test and the dynamometer test are performed. The comparison of experimental and theoretical results shows a good agreement and the analysis indicates that mode coupling due to friction force is responsible for disc brake squeal. And squeal type Instability is Investigated by using the parametric analysis. This indicates parameters which have influence on the propensity of brake squeal. This helped to validate the analysis model and establish confidence in the analysis results. Also they may be useful during system development or diagnostic analysis.

• 가족자원경영과 정책
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• 제11권4호
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• pp.55-71
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• 2007

The purpose of this study was to explore a self-diagnostic indicator for measuring a healthy family by adopting the theme of "happiness", which has surfaced as the most interesting in many academic fields recently. Though the basic concept of a healthy family may be shared by everyone, the criterion of happiness varies from one family to another. Therefore, it is desirable that the tool be made in such a way that every member of the family can check their health from a holistic perspective, rather than diagnosing health and happiness from the perspective of professionals. So, this study was aimed at diagnosing a family by using a tool named GAMMA model, so each family member can recognize problems and find the best options to solve it. This study. has a significant meaning in that it has tried to diagnose families by introducing the GAMMA model into domestic science for the first time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2486-2488
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• 1998

In this paper, Prameters esimated t using AR model in order to approach linearly the heart sound which include the nonlinear characteristic from the characteristics based on a statistical theory. The parameters which is figured out using AR model is a very important information which show the characteristic heart sound In this paper parameters estimated using autocorrelation method and order selected by proposed Akaike[6] method. Compared the similirities of the spectrums between estimated by using AR model and estimated by using FFT method.

• 한국자동차공학회논문집
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• 제7권7호
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• pp.1-14
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• 1999

In the present study, the flame factor which primarily influence the simulation accuracy of the combustion process in a gasoline engine was modeled as a nonlinear function of turbulent intensity to laminar flame speed ratio. Multi-length-scale production rate model for turbulent kinetic energy equation was introduced to consider the different length scales of the swirling and tumbling motions in cylinder on the production rte of turbulent kinetic energy. By7 introducing the multi-length-scale production rate model for the turbulent kinetic energy equation, the predictions of turbulent burning velocity , cylinder pressure, mass burning rate and engine performance of a gasoline engine can much be improved.