• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.161-162
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• 1997

It is very useful to perform the surgery simulation before implanting TAH(Total Artificial Heart} in a patient. The space of chest and the shape of vessels are different from patient to patient. So, It is desirable to customize a TAH design to the anatomy structure of a patient. Several studies are performed to visualize and explain the 3D structure of heart. These studies are performed using 2-dimensional ref or mated images and simple measurement. Anatomy structure of a human heart is not so simple. It is 4dimensional structure ; 3-dimensional plus time, heart beating. 3-dimensional reconstruction schemes of medical images developed for about 10 years are usually categorized into two types of rendering technique ; surface rendering and volume rendering. Volume rendering is preferable in medical image processing field because this technique can be applied without considering the complexity of geometry and change of field of interest. The usable space in the chest of patient can be measured by 3D volume matching of patient trunk and TAH model. This space changes with time. In this research we have developed the 4-dimensional volume match program of patient and TAH model. 3-dimensional rendered set of volumes along time were used to simulate TAH fitting trial. The quantitative measurement from this simulation could be applied to customize TAH design.

• 한국정보처리학회논문지
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• 제4권5호
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• pp.1297-1307
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• 1997

본 논문에서는 인터넷 상에서 멀티미디어 메일을 주고 받을 수 있게 하는 멀티 미디어 메일 시스템을 구현하였다. 이 메일 시스템은 기존의 텍스트 위주의 e-mail 시스템을 확정한 것으로 텍스트, 이미지,,MPEG 비디오 및 바이너리 데이터의 전송을 가능하게 한다. 멀티미디어 데이터를 표현하기 위해서 기존의 RFC-822 포맷을 확정한 MIME(Multipurpose Untemet Nail Extension)를 그대로 사용한다. 한편, 메이팍스 검색 프로토콜로는 현재 널리 사용되고 있는 POP(Post Office Pritocol)보다 기능이 우수한IMAP(Internet Mail Access Prltocol)을 사용한다. 메일클라이언트는 PC에 구현 하였고 메일 서버는 UNX 시스템에 구현하였다. 구현한 메일 시스템은 바이너리 파일의 추가 기능을 제공하며, 수신된 멀티미디어 메일을 검색하는 경우 수신 윈도우 내에서 포스트스크립트뷰어, MPEG 디코더 등의 응용프로그램과의 직접적인 인터페이스 기능을 제공하여 사용자가 다양한 형태의 메일 메시지를 듣고 볼 수 있게 한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.21-29
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• 1994

This paper presents a method to accommodate failures that affect aircraft dynamical characteristics, especially control surface jams on a large transport aircraft. The approach is to use the slow effectors, such as the stabilators or engines, in the feedforward manner. The simulation results indicate the performance of the RFCS. In some cases of control surface jam, the aircraft cannot recover without using the stabilators. Although the inputs to the slow effectors are determined using the nominal parameters, the effects of parameter change can be compensated by adjusting the control parameters for the fast surfaces. In the case of rudder jam, if the remaining control surfaces and the differential thrust cancel the moments produced by the stuck rudder, using the engine control improves time responses and reduces deflection angles of the control surfaces. If not, however, the aircraft starts a large rolling motion following a yawing motion. In that case, the stabilators should be used to damp the induced rolliig motion, instead of trying to directly cancel the moments caused by the stuck rudder. Unfortunately, the proposed control law for the stabilators does not give such inputs, because it does not take into account the dynamical effects which stuck surfaces have on the aircraft motions. However, we have shown through simulation that the aircraft can be recovered by giving the stabilators the control inputs that counteract the induced rolling moment. Besides, the method has also been shown through simulation to be effective in maintaining control during a situation similar to an actual accident. Finally let us mention a problem with the RFCS. As stated above, we have not established a method to select a trim point which call be reached as easily as possible using the remaining control effectors. In fact, recovery performance considerably depends on the trim states. As pointed out in Ref. 11, finding the best trim point for impaired aircraft will be one of the most difficult questions in RFCS design.

• 대한전자공학회논문지SD
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• 제47권12호
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• pp.1-7
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• 2010

본 논문은 멀티레벨을 갖는 PoRAM 셀의 데이터를 센싱하는 기법에 관하여 제안하였다. PoRAM은 유기물질을 사용한 단위 셀의 상,하단 전극에 전압을 가했을 때 나타나는 저항 상태의 변화로 셀 데이터를 구분하는 메모리 소자이다. 특히 한 셀당 최대 4 레벨의 안정된 저항 값을 가지므로 멀티레벨 셀로 활용이 가능하다. 따라서 멀티레벨의 센싱을 위해 어드레스 디코딩 방법, 센스 앰플리파이어, 이를 위한 제어 신호 등을 새롭게 제안하였다. 센스 앰플리파이어는 셀에 흐르는 전류를 입력 값으로 받아 설정된 기준 전류($I_{REF}$)와 비교하는 전류 비교기를 기본으로 구성되며 전류를 증폭하기 위해 낮은 입력 임피던스를 갖도록 설계되었다. 제안된 기법에 의해 설계된 회로는 $0.13{\mu}m$ CMOS 공정 라이브러리를 사용하여 설계되었고, 이를 사용함으로써 단위 셀에 흐르는 서로 다른 4 가지 전류 값이 각각 데이터 "00", "01", "10", "11"으로 정확히 센싱 되는 것을 검증하였다.

• Genomics & Informatics
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• 제9권3호
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• pp.102-113
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• 2011

C-terminal SRC kinase (CSK) is a ubiquitously expressed, cytosolic enzyme that phosphorylates and inactivates several SRC family protein tyrosine kinases. Recent genomewide association studies have implicated CSK in the regulation of blood pressure. The current study aim is to determine the blood pressure association of the genes regulated by CSK down-regulation. The CSK mRNA expression was downregulated in vascular smooth muscle cells using small interfering RNA (siRNA). CSK mRNA levels fell by 90% in cells that were treated with CSK siRNA; the RNA from these cells was examined by microarray using the Illumina HumanRef-8 v3 platform, which comprises 24,526 reference mRNA probes. On treatment with CSK siRNA, 19 genes were downregulated by more than 2-fold and 13 genes were upregulated by more than 2-fold. Three (CANX, SLC30A7, and HMOX1) of them revealed more than 3 fold differential expression. Interestingly, the HMOX1 SNPs were associated with diastolic blood pressure in the 7551 Koreans using Korea Association REsource data, and the result was supported by the other reports that HMOX1 linked to blood vessel maintenance. Among the remaining 29 differentially expressed genes, seven (SSBP1, CDH2, YWHAE, ME2, PFTK1, G3BP2, and TUFT1) revealed association with both systolic and diastolic blood pressures. The CDH2 gene was linked to blood pressures. Conclusively, we identified 32 differentially expressed genes which were regulated by CSK reduction, and two (HOMX1 and CDH2) of them might influence the blood pressure regulation through CSK pathway.

• Toxicological Research
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• 제26권1호
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• pp.21-28
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• 2010

As the frequency and the intensity of so called Asian dust (AD) events have increased, public concerns about the adverse health effects has spiked sharply over the last two decades. Despite the recent reports on the correlation between AD events and the risk for cardiovascular and respiratory disease, the nature of the toxicity and the degree of the risk are yet largely unknown. In the present study, we investigated the effects of the dichloromethane extract of AD (AD-X) and that of urban dust (NAD-X) collected during a non-AD period on gene expression in HL-60 cells using Illumina Sentrix HumanRef-8 Expression BeadChips. Global changes in gene expression were analyzed after 24 h of incubation with 50 or 100 ${\mu}g$/ml AD-X and NAD-X. By one-way analysis of variance (p < 0.05) and Benjamini-Hochberg multiple testing correction for false discovery rate of the results, 573 and 297 genes were identified as AD-X- and NAD-X-responsive, respectively. The genes were classified into three groups by Venn diagram analysis of their expression profile, i.e., 290 AD-X-specific, 14 NAD-X-specific, and 283 overlapping genes. Quantitative realtime PCR confirmed the changes in the expression levels of the selected genes. The expression patterns of five genes, namely SORL1, RABEPK, DDIT4, AZU1, and NUDT1 differed significantly between the two groups. Following rigorous validation process, these genes may provide information in developing biomarker for AD exposure.

• Journal of Advanced Marine Engineering and Technology
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• 제10권2호
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• pp.156-164
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• 1986

In the case of boiling on high temperature wall, vapor film covers fully or parcially the surface. This phenomenon, film boiling or transition boiling, is very important in the surface heat treatment of metal, design of cryogenic heat exchanger and emergency cooling of nuclear reactor. Mainly supposed hydraulic-thermal accidents in nuclear reactor are LCCA (Loss of Coolant Accident) and PCM (Power-Cooling Mismatch). Recently, world-wide studies on reflooding of high temperature rod bundles after the occurrence of the above accidents focus attention on wall temperature history and required time in transient cooling process, wall superheat at rewet point, heat flux-wall superheat relationship beyond the transition boiling region, and two-phase flow state near the surface. It is considered that the further systematical study in this field will be in need in spite of the previous results in ref. (2), (3), (4). The paper is the study about the fast transient cooling process following the wall temperature excursion under the CHF (Critical Heat Flux) condition in a forced convective subcooled boiling system. The test section is a vertically arranged concentric annulus of 800 mm long and 10 mm hydraulic diameter. The inner tube, SUS 304 of 400 mm long, 8 mm I.D, and 7 mm O.D., is heated uniformly by the low voltage AC power. The wall temperature measurements were performed at the axial distance from the inlet of the heating tube, z=390 mm. 6 chromel- alumel thermocouples of 76 .mu.m were press fitted to the inner surface of the heating tube periphery. To investigate the heat transfer characteristics during the fast transient cooling process, the outer surface (fluid side) temperature and the surface heat flux are computed from the measured inner surface temperature history by means of a numerical method for inverse problems of transient heat conduction. Present cooling (boiling) curve is sufficiently compared with the previous results.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.68-73
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• 2002

In standard teletherapy, a treatment plan is generated with the aid of a treatment planning system, but it is common to perform an independent monitor unit verification calculation (MUVC). In exact analogy, we propose and demonstrate that a simple and accurate MUVC in Intensity Modulated Radiotherapy (IMRT) is possible. We introduce a concept of Modified Clarkson Integration (MCI). In MCI, we exploit the rotational symmetry of scattering to simplify the dose calculation. For dose calculation along a central axis (CAX), we first replace the incident IMRT fluence by an azimuthally averaged fluence. Second, the Clarkson Integration is carried over annular sectors instead of over pie sectors. We wrote a computer code, implementing the MCI technique, in order to perform a MUVC for IMRT purposes. We applied the code to IMRT plans generated by CORVUS. The input to the code consists of CORVUS plan data (e.g., DMLC files, jaw settings, MU for each IMRT field, depth to isocenter for each IMRT field), and the output is dose contribution by individual IMRT field to the isocenter. The code uses measured beam data for Sc, Sp, TPR, (D/Mu)$\_$ref/ and includes effects from MLC transmission, and radiation field offset. On a 266 MHZ desktop computer, the code takes less than 15 sec to calculate a dose. The doses calculated with MCI algorithm agreed within +/- 3% with the doses calculated by CORVUS, which uses a 1cm x 1cm pencil beam in dose calculation. In the present version of MCI, skin contour variations and inhomogeneities were neglected.

• 한국정밀공학회지
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• 제28권6호
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• pp.724-731
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• 2011

Dew generation on an outer surface is considered as an important issue to be settled in the field of home appliances. In the case of a refrigerator that is subject to the dew generation problem on the surface of an outer-door of refrigeration thread, and so as to solve this problem, the electric heater is generally used for drying the dew. However, the heater inevitably requires electrical power consumption that is one of critical issues on the refrigerator. In this study, to prevent dew generation without the heater, a method of using induced heat from room temperature was proposed. In edge sides of a door, high conductive plates are installed and received the heat from outside that is relatively high temperature, and the heat is transferred onto dew generation region. Using prototypes, performance test was conducted under a certain temperature and humidity condition. The experimental results show that the surface temperature on the dew generation region was increased about $0.3{\sim}2.5^{\circ}C$ without use of any heater.

• 한국식품과학회지
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• 제25권6호
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• pp.643-648
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• 1993

표준온도 상당시간을 이용하여 규칙적인 온도변화 조건에서 식품의 품질변화를 간편하게 예측하는 근사식의 유효성을 밝히기 위하여, 비등온 가속조건 및 상온저장 조건에서 Sucrose 가수분해속도를 측정한 설험자료로 비교, 분석을 분석하였다. 정속가열 (定速加熱) 가속(加速)실험을 통해 구한 sucrose의 가수분해 반응은 1차 반응이고, 활성화에너지는 25.84kcal/mol이었으며, 반응속도상수는 pH가 감소함에 따라 직선적으로 증가하였다. 하루 동안의 온도변화를 sine wave 형태 온도변화로 가정하고 하루 동안에 일어난 품질변화를 표준온도 $T_{ref}$에서 몇일 동안에 일어난 변화에 상당하는가를 의미하는 표준온도 상당시간 $T_{eq.i}$를 이용하여 품질변화를 근사적으로 간단히 예측하는 방법을 제안하였다. Sucrose 액체 모델 시스템을 sine wave 형태의 규칙적인 온도변화 조건에서의 가속 가수분해실험 결과와 $T_{eq.i}$를 이용하여 품질변화를 computer simulation한 결과, 실험값과 예측값과의 상관계수는 0.99로서 잘 일치하였으므로 표준온도상당시간을 이용한 예측 모델의 유효함을 확인하였다. 뿐만 아니라 sucrose 모델 시스템을 실제 상온 저장한 실험결과와 계절적 온도변화를 computer simulation하여 예측한 값과는 상관계수가 0.92로서 잘 일치하였다.