• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.96-102
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• 2008

For centuries now, wind tunnels have been a key element in scientific research in a number of fields. Experimenting with racecars, airplanes, weather patterns, birds, and various other areas has been made much easier because of its development. In the racing field, for example, the information gathered from this testing can mean the difference between winning and losing a race. Weather simulations can also provide valuable information regarding building stability and safety. This has become very important when designing buildings today. Valuable information concerning bird flight has also been collected based on wind tunnel testing. Wind tunnels have a variety of important uses in the world today. Wind tunnel that used here is an open loop low speed wind tunnel. The fundamental principles of this tunnel is moving the air using exhaust fan In the rear side, and placing the cube in the external balance system which used to measure the working force. This experiment is using 50mm cube of finished wood. From this experiment we can get Drag Force (FD), The Reynolds Number (Re) and The Coefficient of Brae (CD).

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.387-388
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• 2008

Finding reasonable flexural modes from the full vehicle modal testing has always been a difficult job to N&V engineers due to FRF inconsistency, nonlinearity, heavy damping and, in many cases, interactions between global body structural modes and massive isolate/non-isolated subsystem modes. This paper provides a brier overview of the mode map validation using single-run FRF measurement with highly sensitive accelerometers fur the full vehicle modal analysis and then it can be used to characterize the vehicle's global/local vibration performances, especially customer perceived "structural feel" typically below 40Hz.

• 턱관절균형의학회지
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• 제7권1호
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• pp.24-31
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• 2017

Applied Kinesiology (AK) is an evaluation system on the functional balance and integration of the body. Functional aspects of the triad of health are evaluated through muscle testing to see if the balance and integration is in an optimal status or is influenced by a given environmental stimulation. Triad of health refers to the structural, chemical, and psychological aspects of the body. Muscle testing in AK is a functional neurological assessment of muscular response to a given environmental stimulation in a given individual. Meridian system and stomatognathic system as in TMJ balancing medicine serve as one of the theoretical basis of AK. This article reviews core concepts of AK, discusses yin-yang balance medicine perspectives and clinical applications of it.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1523-1526
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• 2007

This study introduces the testing results of the carbody. The load test was performed to evaluate the structural characteristic and stability of the stainless carbody. The carbody is made of stainless steel. The body structure consisted of side frame, under frame, roof frame, and end frame. Of these components, the side frame and under frame were the most important components considering the vehicle and passenger loads. Loading test were performed under the condition based on "Performance Test Standard for Electrical Multiple Unit". The test results showed that the body structure is safe and stable under the condition of designed load.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.336.2-336
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• 2002

There are many researches to identify the rigid body properties from the mass-line obtained by impact hammer testing. The correct rigid body properties of the structure may be estimated if the mass-line of the structure could be obtained exactly. When the structure is mounted by elastic materials, the mass-line cannot be read correctly from the impulse response spectrum. The reason is due to the effects of rigid body modes of mounted structure. (omitted)

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.332-337
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• 2005

In order to investigate performance changes, the acceleration, vibration, and braking performance tests were carried out on the electric multiple units (EMUs) with over 20 years operation. According to the testing results, in vibration and braking performance, the similar performance results were obtained as compared with newly manufactured EMUs. However, in terms of acceleration performance, below reference value (3.0 km/h/s) has been obtained. This is mainly due to performance deterioration including traction motor. The precision diagnosis evaluation of deteriorated EMUs will be provided through the overall evaluation of corrosion testing and structural performance of car body.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.409-414
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• 2007

Nowadays, with the advancement of computational mechanics, and vehicle dynamics simulation linked up with virtual testing laboratory(VTL) and virtual proving ground(VPG) technologies has become a useful method for analyzing numerous driving performances and diverse noise/vibration characteristics. In this paper, the analytical vehicle model based on multi-body dynamics theory was developed to investigate the vibration characteristics according to various road conditions. For the purpose, the whole vehicle parameters, each vehicle's part parameter, and part connecting elements such as spring, damper, and bush were measured by an experiment. Also, the vehicle dynamics model, which includes the front suspension, rear suspension, steering, front wheel, rear wheel, and body subsystems has been constructed for computer simulation. With the developed vehicle dynamics model, three forces and three moments measured at each wheel center were applied to evaluate and analyze dynamics and vibration characteristics for miscellaneous road conditions.

• 비파괴검사학회지
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• 제26권2호
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• pp.115-121
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• 2006

유한 요소 해석을 위해서는 형상과 경계, 하중 조건 그리고 물성을 결정하여야 한다. 그러나 살아 있는 인체에 대해서는 실험이 어렵기 때문에 정확한 형상과 물성을 얻기가 매우 어렵다. 본 논문에서는 한국인 표준체형을 가진 젊은 남성의 생체 자기 공명 영상(MRI : magnetic resonance imaging)을 이용하여 내부 장기를 38가지로 구역화 하고 이것을 이용하여 정밀 유한 요소 모델을 만들었다. 또한 인체를 이루고 있는 다양한 물질들 가운데 뼈에 대한 물성을 얻기 위한 연구를 시행하였다. 인체 뼈의 이방성을 표현할 수 있는 물성을 얻기 위해 성인 남성과 여성의 사체에서 얻은 대퇴골두 시편을 RUS(resonant ultrasound spectroscopy)를 사용하여 탄성 계수 행렬을 얻을 수 있었다.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.171-176
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• 2007

An important challenging issue in the automotive industry is the light-weight, safe design and enhancement of crash response of an auto-body structures. These objectives lead to increasing adoption of high strength steel sheet for inner and outer auto-body members. This paper evaluates the dynamic tensile characteristics of high strength steel sheets, HS45R, TRIP60, DP60 and DP100, along the rolling direction and transverse direction. Static tensile tests were carried out at the strain rate of 0.003/sec using the static tensile machine (Instron 5583). Dynamic tensile tests were carried out at the range of strain rate from 0.1/sec to 200/sec using a high speed material testing machine developed. The tensile tests acquire stress-strain relation and strain rate sensitivity of each material. The experimental results show two important aspects for high strength steels: the flow stress increases as strain rate increases; the strain hardening decreases as the tensile stress increases. The experiments also produce interesting results that the elongation does not decrease even when the strain rate increases.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.3043-3050
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• 2022

In Korea, all nuclear power plants (NPPs) participate in annual performance tests including in vivo measurements using the FastScan, a stand type whole body counter (WBC), manufactured by Canberra. In 2018, all Korean NPPs satisfied the testing criterion, the root mean square error (RMSE) ≤ 0.25, for the whole body configuration, but three NPPs which participated in an additional lung configuration test in the fission and activation product category did not meet the criterion. Due to the low resolution of the FastScan NaI(Tl) detectors, the conventional peak analysis (PA) method of the FastScan did not show sufficient performance to meet the criterion in the presence of interfering radioisotopes (RIs), ¹³⁴Cs and ¹³⁷Cs. In this study, we developed an artificial neural network (ANN) to improve the performance of the FastScan in the lung configuration. All of the RMSE values derived by the ANN satisfied the criterion, even though the photopeaks of ¹³⁴Cs and ¹³⁷Cs interfered with those of the analytes or the analyte photopeaks were located in a low-energy region below 300 keV. Since the ANN performed better than the PA method, it would be expected to be a promising approach to improve the accuracy and precision of in vivo FastScan measurement for the lung configuration.