• Journal of Mechanical Science and Technology
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• v.20 no.1
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• pp.19-28
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• 2006

This paper describes rapid prototyping (RP) and reverse engineering (RE) application for orthopedic surgery planning to improve the efficiency and accuracy of the orthopedic surgery. Using the symmetrical characteristics of the human body, CAD data of undamaged bone of the injured area are generated from a mirror transformation of undamaged bone data for the uninjured area. The physical model before the injury is manufactured from Poly jet RP process. The surgical plan, including the selection of the proper implant, pre-forming of the implant and decision of fixation positions, etc., is determined by a physical simulation using the physical model. In order to examine the applicability and efficiency of the surgical planning technology, two case studies, such as a distal tibia comminuted fracture and an iliac wing fracture of pelvis, are carried out. From the results of the examination, it has been shown that the RP and RE can be applied to orthopedic surgical planning and can be an efficient surgical tool.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1950-1952
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• 1999

Pentacene thin films are a component for active layer of Organic thin film transistors. Pentacene film was deposited by Organic Molecular Beam Deposition(OMBD) and electrodes were deposoted by vacuum evaporation. Electrical characterization of Pentacene films were measured by two probe methods, as the results. The Au/Pentacene/Al contact is Ohimic contact. Band diagram of pentacene films were measured by UV-spectrum and Cyclic-Voltammetry method.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1947-1949
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• 1999

Carrier lifetime in silicon power devices caused switching delay and excessive power loss at high frequency switching. We studied transient turn-on/turn-off transient characteristics of electron irradiated and proton irradiated silicon pn junction diodes. Both the electron and proton irradiation of power devices have already become a widely used practice to reduce minority carrier lifetime locally[1]. The sample is n+p junction diode, made by ion implantation on a $20\Omega.cm$ p-type wafer. We investigated turn-on/turn-off transient & breakdown voltage characteristics by digital oscilloscope. Our data show that proton irradiated samples show better performance than electron irradiated samples.

• Journal of Korea Multimedia Society
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• v.17 no.9
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• pp.1104-1114
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• 2014

In large-scale crowd simulations, it is very important for the decision-making system of manipulating interactive behaviors to minimize the computational cost for controlling realistic behaviors such as collision avoidance. In this paper, we propose a large-scale realtime crowd simulation method using the affordance and navigation potential fields such as attractive and repulsive forces of electromagnetic fields. In particular, the model that we propose locally handles the realistic interactions between agents, and thus radically reduces the cost of expensive computation on interactions which has been the most problematic in crowd simulation. Our method is widely applicable to the expression and analysis of various crowd behaviors that are needed in behavior control in computer games, crowd scenes in movies, emergent behaviors of evacuation, etc.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.4
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• pp.303-309
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• 2008

Dense and fine polymer patterns often collapse, as they come into contact with each other at their protruding tips. Resist pattern collapse depends on the aspect ratio of patterns and the surface tension of rinsing materials. The pattern collapse is a very serious problem in microfabrication, because it is one of the factors which limit the device dimensions. The reasons for the pattern collapse are known as the surface tension of rinse liquid, centrifugal force and rinse liquid flow produced in the developing process. In this work, we tried to evaluate the pattern collapse of three-dimensional microstructures that were fabricated by two-photon induced photopolymerization, and showed the way how to reduce the deformation of microstructures.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.201-202
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• 2008

발전소는 부하의 증 감발에 출력조정을 하며 운전하지만 부하가 많이 감소할 때는 발전정지를 하여 부하수요를 맞춘다. 그러나 부하의 증가에 따라 보일러를 다시 기동하는데 때에 따라 보일러의 기동이 실패하거나 지연기동이 발생하여 부하에 신속히 대응하지 못하는 경우가 있다. 보일러 제어를 위해서는 컨트롤하는 종류가 많고, 이들은 상호 연계되어 있어 어느 한 곳의 이상원인 발생이 다른 제어 루프에 영향을 미쳐 점점 더 어렵게 제어되므로 운선원은 신속히 원인 파악과 상태점검 및 분석을 통한 대응으로 안정적인 운전에 최선을 다하여야 한다. 본 논문에서는 발전소 보일러 기동실패로 인한 발전정지 사례에 대하여 원인 분석을 수행하고 동일한 상황이 재현되지 않도록 제어로직을 개선한 내용을 논하고자 한다.

• Journal of the Korean Society of Radiology
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• v.2 no.3
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• pp.33-35
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• 2008

In the neutron capture experiment and calculation, the neutron absorption and scattering are very important. Especially these effects are conspicuous in the resonance energy region and below the thermal energy region. In the present study, we obtained energy dependent neutron absorption ratios of natural rhodium in energy region from 0.003 to 100 eV by MCNP-4B Code. The coefficients for neutron absorption was calculated for several types of thickness. In the lower energy region, neutron absorption is larger than higher region, because of large capture cross section (1/v). Furthermore it seems very different neutron absorption in the large resonance energy region. These results are very useful to decide the thickness of sample and shielding materials.

• Journal of the Korean Society of Radiology
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• v.3 no.3
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• pp.23-25
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• 2009

Gd-157 material has very large neutron capture cross section in the thermal region. So it is very useful to shield material for thermal neutrons. Futhermore, in the neutron capture experiment and calculation, the neutron absorption and scattering are very important. Especially these effects are conspicuous in the resonance energy region and below the thermal energy region. In the case of very narrow resonance, the effect of scattering is to be more considerable factor. In the present study, we obtained energy dependent neutron absorption ratios of natural indium in energy region from 0.003 to 100 keV by MCNP-4B Code. The coefficients for neutron absorption was calculated for circular type and 1 mm thickness. In the lower energy region, neutron absorption is larger than higher region, because of large capture cross section (1/v). Furthermore it seems very different neutron absorption in the large resonance energy region. These results are very useful to decide the thickness of sample and shielding materials.

• Journal of the Korean Society of Radiology
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• v.5 no.4
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• pp.217-221
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• 2011

$^{237}Np$ is very important material in the fission products of nuclear reactors. Resonance integral(RI) tests of this material is necessary to check between the experiments and the evaluated data. Such feedback to the evaluated data is very important to correct data and improve of codes. The RI for the $^{237}Np(n,{\gamma})^{238}Np$ reaction were measured by using the 46-MeV electron linear accelerator (linac) at the Research Reactor Institute, Kyoto University (KURRI). The measurement was performed in the energy region from 0.005 eV and 10 keV. RI obtained as 804.7 barns, compared with those of the evaluated data in JENDL-4.0 and Mughabghab.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.25 no.1
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• pp.39-41
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• 2014

Spindle cell carcinoma is an uncommon type of squamous cell carcinoma characterized by a mixture of malignant epithelial and mesenchymal cells. Most spindle cell tumors are polypoid and pedunculated. It is usually detected at an early stage, removed by laryngoscope guided polypectomy at the time of diagnosis, and seems to have good prognosis. The tools for diagnosing spindle cell carcinoma are histopathological analysis and immunohistochemical analysis. With reviews of literature, we report a 72-year-old patient complaining of hoarseness and dysphagia who was later diagnosed as spindle cell carcinoma.