• Journal of Korean Society of Steel Construction
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• v.8 no.4 s.29
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• pp.19-29
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• 1996

In this paper, it is presumed that the stress time history was generated by simulation method and investigated compatibility in regard to the reappearance of stress time history. In this procedure, the identified frequency distribution of stress range of the steel railroad bridge varies with the rational values of cut off point and bar width. Thus, we show variable aspect of the equivalent stress range results from change of cut off point and bar width. In addition, we analyze the variable of RMC and RMS model due to the cut off point and bar width of the measured stress history which influencs the prediction of fatigue life in the steel railroad bridge. The simulated stress time history is carried out by the superposition method incorporating the vertical load with rotation moment obtained from the Hermition interpolation function, and compared with developing stress results from measured maxi mum stress. Through this study, we can estimate the remaining fatigue life from a safety point of view and comparative accuracy.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1059-1061
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• 2002

A FE model is to develop a personalized biomechanical model of the scoliotic spine that will allow the design of clinical test providing optimal estimation of the post-operation results. A flexible multi-body model of the spine including rib cage, clavicle, and scapular was developed to simulate several mobility simulations. Vertebrae, clavicle and scapular were represented using rigid bodies and ribs and sternum were modeled as flexible bodies. Kinematical Joints and spring elements were used to represent the intervertebral disc and ligaments respectively. Postero-anterior and lateral radiographics of a scoliotic spine were used to represent a 3D reconstruction. CT data for same patient were also used to verify vertebrae rotation driven from postero-anterior and lateral radiographic images. Simulated results showed good reducibility almost uniformly distributed along the spinal segments. It was also found that boundary and loading conditions, required to mimic the operation procedures, were proven to be very sensitive parameters to its results rather than its mechanical properties

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.721-724
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• 2002

본 논문에서는 카메라 파라메타의 하나로서 이미지 센터를 구하는 방법에 대해 소개한다. 3 차원 게임, 그래픽스, 의료, 측정, 형상 복원 등의 응용에 거리 정보를 포함하는 3 차원 정보는 필수적이며 이러한 정보를 추출하기 위해서는 카메라 캘리브레이션을 반드시 거쳐야 한다. 이미지 센터는 대부분의 경우에 카메라 파라메타를 구하기 위한 모델 추정 방법에서 하나의 값으로 취급되는 경우가 많아 이미지 센터 외의 카메라 파라메타의 정확도에 영향을 받을 수 있다. 본 연구에서는 카메라 회전을 이용하여 이미지 센터만을 독립적으로 구하는 방법을 제안하며 그 편이성과 반복성, 정확도를 카메라 회전 모델링 시뮬레이션과 실험을 통해 보인다.

• Proceedings of the IEEK Conference
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• summer
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• pp.133-136
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• 2004

We are going to procedure various view from two frontal image using trifocal tensor. We found that warping is effective to produce synthesized poses of a face with the small number of mesh point of a given image in previous research[1]. For this research, fundamental matrix is important to calculate trifocal tensor. So, in this paper, we investigate two existing algorithms: Hartley's[2] and Kanatani's[3]. As an experimental result, Kenichi Kantani's algorithm has better performance of fundamental matrix than Harley's algorithm. Then we use the fundamental matrix of Kenichi Kantani's algorithm to calculate trifocal tensor. From trifocal tensor we calculate new trifocal tensor with rotation input and translation input and we use warping to produce new virtual views.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.69-72
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• 2002

Human face detection has many applications such as face recognition, face or facial feature tracking, pose estimation, and expression recognition. We present a new method for automatically segmentation and face detection in color images. Skin color alone is usually not sufficient to detect face, so we combine the color segmentation and shape analysis. The algorithm consists of two stages. First, skin color regions are segmented based on the chrominance component of the input image. Then regions with elliptical shape are selected as face hypotheses. They are certificated to searching for the facial features in their interior, Experimental results demonstrate successful detection over a wide variety of facial variations in scale, rotation, pose, lighting conditions.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1539-1542
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• 2002

In layout of LSI and PWB, block pack- ing problem is very important in order to reduce chip area. Sequence-pair is typical one of conventional pack- ing method and can search nearly-optimal solution by using Simulated Annealing(SA). SA takes huge computation time due to evaluating of various packing results. Therefore, Sequence-pair is not effective enough for fast layout evaluation including estimation of wire length and rotation of every blocks. This paper proposes an efficient block packing method to minimize wire length and chip area. Our method searches an optimal packing efficient- ly by using a cluster growth algorithm with changing the most valuable packing score on packing process.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.71.1-71.1
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• 2014

To investigate physical properties of Solar pores, we use SDO/HMI data from 2010 to 2013. For this, we select single and isolated pores from the active region (Axx, Bxo, Bxi and Bxc-type) listed in Solar Region Summary. Pore is defined by connected pixels satisfying the intensity threshold from pixel of minimum intensity. We try to obtain area, intensity, magnetic field, and Doppler velocity of pores from HMI data. After removing the effects of orbital motion of the SDO satellite and differential rotation of the Sun, we identify that significant daily variations of Doppler velocity with non-zero ordinates still remain in the umbral region, and the artifact is quite dependent on the strength of magnetic field and radial component of velocity of SDO satellite. In this study we develope empirical model to remove the artifact. A preliminary result on the elimination of the artifact will be presented.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2333-2335
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• 1998

Recently, the development of computer achieves a system which is similar to the mechanics of human visual system. The 3D measurement using monocular vision system must be achieved a camera calibration. So far, the camera calibration technique required reference target in a scene. But, these methods are inefficient because they have many calculation procedures and difficulties in analysis. Therefore, this paper proposes a native method that without reference target in a scene. We use the grid type frame with different line widths. This method uses vanishing point concept that possess a rotation parameter of the camera and perspective ration that perfect each line widths into a image. We confirmed accuracy of calibration parameter estimation through experiment on the algorithm with a grid paper with different line widths.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2582-2584
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• 2001

In this paper, this system which constantly control rotation speed of compressor is designed to use in idling state as traffic jam. Also this system is designed to improve reduction of cooling efficiency when sloping and starting a bus. The estimation of designed system in this paper is performed in the laboratory where KS-R-1053 is satisfied. We come to the conclusion that this system is more excellent than the present system in point of cooing ability and response characteristic of controller.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.777-783
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• 2000

As the disk rotation speed increases in information storage devices, aerodynamically excited disk vibration is induced by airflow around the disk. This paper investigates both experimental and theretical studies on the flutter instability. From the experimental results using an ASMO disk, it is found that the three nodal diameter mode of the optical disk experiences its flutter instability around 8750 rpm. At the flutter speed, the amplitude of the corresponding mode increases dramatically and the backward natural frequency does not increase with increasing rotational speeds. The experimental results on flutter instability are compared with analytical predictions.