• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.359-366
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• 2016

The normal tissue in radiation therapy, to minimize radiation, it is most important to maximize local tumor control rates in intensive research the exact dose to the tumor sites. Therefore, the initial, therapist accuracy of detecting movement of the patient fatigue therapist has been a problem that is weighted down directly. Also, by using a web camera, a difference value between the image to be updated to the reference image is calculated, if the result exceeds the reference value, using the system for determining the motion has occurred. However, this system, it is not possible to quantitatively analyze the movement of the patient, the background is changed when moving the treatment bed in the co-therapeutic device was not able to sift the patient. In this paper, using a alpah(${\alpha}$) filter index is an attempt to solve these limitations points, quantifies the movement of the patient, by separating a background image of the patient and treatment environment, and movement of the patient during treatment It senses only, it was possible to reduce the problems due to patient movement.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.77-77
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• 2008

금(Au)이나 은(Ag)과 같은 귀금속 물질로 형성된 금속 나노 구조체는 표면 플라즈몬 공진(Surface Plasmon Resonance, SPR) 현상과 이의 국부 환경(local environment) 변화에 대해 민감한 의존성으로 인하여 생화학적 센서로의 응용이 주목 받고 있다. 표면 플라즈몬 공진은 광 흡수와 광 산란을 수반하는데, 두 가지 특성 모두 분광학적 신호검출방식으로 센서에 응용가능하다. 이 중 광 산란을 이용하는 방식은 광원의 배경잡음 효과가 배제되기 때문에 단일 입자 검출에 유리하다. 광 흡수와 광 산란 특성은 금속 나노 구조체는 크기, 형상, 주변 매질, 물질의 선택에 따라서 영향을 받는다. 본 연구에서는 금 나노 디스크(nanodisc)의 형상에 따라서 여기 되는 표면 플라즈몬이 광 흡수와 광 산란 특성에 미치는 영향을 가시광과 근적외선 영역에 대해서 불연속 쌍극자 근사법(Discrete Dipole Approximation, DDA)을 이용하여 전사모사(simulation) 하였다. 금 나노 디스크의 형상과 플라즈몬 특성 간의 관계는 공명 파장과 산란 양자 거둠율(scattering quantum yield, $\eta$)을 이용하여 분석하였고, 센서로서의 응용을 가늠하기 위해 주변 매질의 굴절률을 조절하여 그에 따른 민감도(sensitivity )를 비교하였다. 나노 디스크의 모양이 판상에 가까워질수록 공명 파장은 적색 편이하였고 광 산란 효율과 민감도는 증가하는 현상이 나타났다. 또한, 산란 양자 거둠율은 증가하다가 완만하게 감소하는 경향이 나타났다.

• Journal of the Korea Convergence Society
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• v.8 no.4
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• pp.189-197
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• 2017

In the design of an automotive structural component, one of the more important tasks for a design engineer is to determine the life of the component and to ensure that the component will not fail prematurely. In order to accomplish this, a design engineer will first use simple section analysis to come up with a section shape in the concept design stage and use more advanced analysis for stress level. At this stage, the analysis should focus on understanding overall behavior in terms of load paths and gross stress levels. A model that is adequate for a stiffness analysis of the structure will usually provide an adequate level of stress information in the design process. To perform a detailed stress analysis, the structure models must have the detailed local areas such as stress concentrations or force(or displacement) distributions. This paper is to present the design considerations for the stress analysis of automotive structure.

• Journal of the Korean Institute of Gas
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• v.11 no.3
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• pp.1-6
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• 2007

The heat transfer coefficient and pressure drop during gas cooling process of $CO_2$ (R-744) in inclined helical coil copper tubes were investigated experimentally. The main components of the refrigerant loop are a receiver, a variable-speed pump, a mass flow meter, a pre-heater and a inclined helical coil type gas cooler (test section). The test section consists of a smooth copper tube, which is specified as the inner diameter of 4.55 mm. The refrigerant mass fluxes were varied from 200 to $600kg/m^2s$ and the inlet pressures of gas cooler were done 7.5 to 10.0 (MPa). The heat transfer coefficients of $CO_2$ in the inclined helical coil tubes increase with the increase of mass flux and gas cooling pressure of $CO_2$. The pressure drop of $CO_2$ in the gas cooler shows relatively good coincidence with those predicted by Ito's correlation developed for single-phase in a helical coil tube. The local heat transfer coefficient of $CO_2$ is well coincident with the correlation by Pitla et al. However, at the region near pseudo-critical temperature, the experiments indicate higher values than the Pitla et al. correlation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1231-1239
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• 2010

The aim of this study was developing the non-invasive focused magnetic stimulation system(NI_FMSS) that can stimulates acupoints which are small parts and knotted muscular tissues. To evaluate pain treatment effect of the NI_FMSS, we caused muscle fatigue to 25 subjects in biceps of the arm. Then, we stimulated acupoints(trigger points) HT2 using low frequency stimulator(10 subjects) and NI_FMSS(10 subjects). The other 5 subjects had not been stimulated. We analyzed muscle fatigue recovery with median frequency, RMS and median power in frequency domain for 5 days. We checked the magnetic stimulation effect on acupoint by evaluation of muscle fatigue recovery. Therefore, we identified that the NI_FMSS was more efficient system to relieve muscle pain than electric-stimulation system.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.2
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• pp.93-100
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• 2014

3D object recognition using only 2D images is a difficult work because each images are generated different to according to the view direction of cameras. Because SIFT algorithm defines the local features of the projected images, recognition result is particularly limited in case of input images with strong perspective transformation. In this paper, we propose the object recognition method that improves SIFT algorithm by using several sequential images captured from rotating 3D object around a rotation axis. We use the geometric relationship between adjacent images and merge several images into a generated feature space during recognizing object. To clarify effectiveness of the proposed algorithm, we keep constantly the camera position and illumination conditions. This method can recognize the appearance of 3D objects that previous approach can not recognize with usually SIFT algorithm.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.255-259
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• 2022

Solar membrane steam generation is a very promising technology that can harvest purified water from seawater or wastewater during the current danger of running out of pure water. However, solar Membrane steam generation had direct contact with water, making it difficult to increase the efficient amount of evaporation. Here, we propose solar membrane steam generator composed of polydimethylsiloxane (PDMS) and graphene oxide (GO) and improved evaporation through wettability control in part throughout the water-absorbing membrane. Wettability control has shown significant improvements in thermal localization and temperature rise in the area of heat exchange with sunlight. The evaporator has an evaporation rate of 1.54 kg m^-2 h^-1 under 1 sun irradiation. The results showed that Solar membrane steam evaporation can effectively harvest pure water through an increase in evaporation.

• Korean Chemical Engineering Research
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• v.61 no.1
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• pp.155-161
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• 2023

Ion concentration polarization (ICP) is one of the essential important mechanisms for biomolecule preconcentration devices as well as a fundamental transport phenomenon found in electrodialysis, electrochemical cell, etc. The ICP triggered by externally applied voltage enables the biomolecular analyte to be preconcentrated at an arbitrary position by a locally amplified electric field inside the microchannel. Conventional preconcentration methodologies using the ICP have two limitations: uncertain equilibrium position and hydrodynamic instability of preconcentration plug. In this work, a new preconcentration method in the dead-end microchannel around cation exchange membrane was numerically studied to resolve the limitations. As a result, the numerical model showed that the analyte was concentrated at a shock front developed in a geometrically confined dead-end channel. Furthermore, the electrokinetic behaviors for preconcentration dynamics were analyzed by changing microchannel's applied voltage and volumetric charge concentration of microchannel as key parameters to describe the dynamics. This work would provide an effective means for a point-of-care platform that requires ultra-fast preconcentration method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.6-8
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• 2022

Many systems that use images through object recognition using deep learning have provided various solutions beyond the existing methods. Many studies have proven its usability, and the actual control system shows the possibility of using it to make people's work more convenient. Many studies have proven its usability, and actual control systems make human tasks more convenient and show possible. However, with hardware-intensive performance, the development of models is facing some limitations, and the ease with the use and additional utilization of many unupdated models is falling. In this paper, we propose how to increase utilization and accuracy by providing additional information on the emotional regions of colors and objects by utilizing learning and weights from HSV color histograms of local image data recognized after conventional stereotyped object recognition results.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.334-342
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• 2002

Purpose : The aim of this study was to determine if postoperative adjuvant chemotherapy (CT) alone and concurrent chemoradiation (CCRT), following radical surgery, improved the disease free survival (DFS) and overall survival (OS) in rectal cancer AJCC stage II and III patients. Materials and Methods : A total of 144 patients with AJCC stage II and III rectal cancer who had had radical surgery between 1989 and 1999 were included in the study. Of these patients, 72 had been treated with postoperative CT, and the other 72 with postoperative CCRT. The chemotherapy regimen consisted of oral UFT on a daily basis for $1\~12$ months (median 12 months) or 5-FU ($500\;mg/m^2$ for 5 days) intravenous (IV) chemotherapy with 4 week intervals for $1\~18$ cycles (median 6 cycles). Radiation of 4,500 cGy was delivered to the surgical bed and regional pelvic lymph nodes area, followed by $540\~1,440\;cGy$ (median 540 cGy) boost to the surgical bed. The follow-up period ranged from 20 to 150 months, with a median of 44 months. Results : The 5-year OS was $60.9\%\;and\;68.9\%$ (p=0.0915), and the 5-year DFS was $56.1\%\;and\;63.8\%$ (p=0.3510) for postoperative CT and postoperative CCRT, respectively. In the stage nm patients, the 5-year OS was $71.1\%\;and\;92.2\%$, and the 5-year DFS was $57.3\%\;and\;85.4\%$ for postoperative CT and CCRT, respectively. The OS was significantly improved (p=0.0379) but the DFS was not with postoperative CCRT compared to the postoperative CT (p=0.1482). In the stage III patients, the 5-year OS was $52.0\%\;and\;55.0\%$, and the 5-year DFS was $47.8\%\;and\;49.8\%$ for postoperative CT and postoperative CCRT. There were no statistically significant differences between postoperative CT and CCRT (p=0.4280 and p=0.7891) in OS and DFS. The locoregional relapses were $16.7\%\;and\;12.5\%$ for postoperative CT and CCRT, respectively. The distant relapses were $25.0\%\;and\;26.4\%$ for postoperative CT and CCRT, respectively. Conclusion : These results showed that postoperative CCRT compared with CT alone improved OS in stage II patients. Although there was no statistical significance, the addition of postoperative RT to CT reduced locoregional relapses compared to CT alone.