• Genomics & Informatics
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• 제6권2호
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• pp.91-94
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• 2008

Single nucleotide polymorphisms (SNPs) are the most abundant form of human genetic variation and are a resource for mapping complex genetic traits. A genome is covered by millions of these markers, and researchers are able to compare which SNPs predominate in people who have a certain disease. The International HapMap Project, launched in October, 2002, motivated us to start the Korean HapMap Project in order to support Korean HapMap infrastructure development and to accelerate the finding of genes that affect health, disease, and individual responses to medications and environmental factors. A Korean SNP and haplotype database system was developed through the Korean HapMap Project to provide Korean researchers with useful data-mining information about disease-associated biomarkers for studies on complex diseases, such as diabetes, cancer, and stroke. Also, we have developed a series of software programs for association studies as well as the comparison and analysis of Korean HapMap data with other populations, such as European, Chinese, Japanese, and African populations. The developed software includes HapMapSNPAnalyzer, SNPflank, HWE Test, FESD, D2GSNP, SNP@Domain, KMSD, KFOD, KFRG, and SNP@WEB. We developed a disease-related SNP retrieval system, in which OMIM, GeneCards, and MeSH information were integrated and analyzed for medical research scientists. The kHapMap Browser system that we developed and integrated provides haplotype retrieval and comparative study tools of human ethnicities for comprehensive disease association studies (http://www.khapmap.org). It is expected that researchers may be able to retrieve useful information from the kHapMap Browser to find useful biomarkers and genes in complex disease association studies and use these biomarkers and genes to study and develop new drugs for personalized medicine.

• 대한기계학회논문집
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• 제16권8호
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• pp.1575-1582
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• 1992

본 연구에서는 정상운전 중인 4사이클 6실린더 터보과급 디젤기관에 갑자기 큰 부하가 작용하였을 경우, 기관 및 과급기 관성 모멘트의 변화가 기관과 과급기의 실제 회전속도, 압축기 압력비, 실린더내 공기유량, 연소효율, 배기온도 등의 과도 응 답성능에 미치는 영향을 시뮬레이션해석과 실험을 통하여 규명하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제37권8호
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• pp.849-854
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• 2013

선박 운항의 경제성, 효율성 및 편리성을 높이면서 친환경 선박에 대한 연구가 지속적으로 이루어지고 있다. 이 중 하나가 전자제어식 디젤 엔진의 개발이다. 자동차용 소형에서는 이미 전자제어식 디젤기관이 주류를 이루고 있으나 선박에서는 안정성 및 신뢰성의 문제로 보급에 어려움을 겪고 있다. 본 연구에서는 이러한 문제를 해결하기 위하여 전자제어식과 캠식 엔진이 동시에 탑재되어 있는 한국해양대학교의 실습선 한바다호의 주기관을 이용하여 두 엔진의 성능을 비교 분석하였다. 그 결과 전자제어식 디젤엔진의 연료소비율이 저감되었으며 특히 저부하에서의 성능이 보다 우수하였다. 또한 연료소비율에 있어서 해상 시운전에서 훨씬 효과적이었다.

• 인지과학
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• 제4권1호
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• pp.243-260
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• 1993

일반적으로 필기자의 습관이나 필기방향 등의 원인으로 종종 필기 문자열에서 기울어짐이 발생한다.이러한 문자열의 기울어짐은 문자 단위 분할시 분할 알고리즘을 복잡하게 만들고 결과적으로 문자인식 성능에도 큰영향을 미친다. 본연구에서는 선 성분의 검출 및 기울기 측정에 유용한 Hough 변환을 이용하여 단어내 수직획의 기울기를 추정하는 방법을 제안한다. 제안된 방법은 입력 필기 문자열 영상의 윤곽선을 Hough 변환에 적용하여 신 성분을 검출하고 기술어진 가도를 추정한다.실제로는 수직획이 아닌 점들이 모여 선 성분으로 검출된 경우을 제거하기 위해 임계치 이하의 길이를 갖는 선 성분은 기울기 추정 대상에서 제외한다.기울기 교정은 x좌표 값만 변환시키는 밀림 변환을 사용한다.제안된 방법의 성능을 검증하기 위해 실제 우편봉투에서 얻은 주소 영상에 대해 실험한 결과 오프라인 필기 한글 문자열의 기울기 추정 및 교정에 있어서 제안된 방법이 기존의 방법보다 우수함을 알수 있었다.

• 한국압력기기공학회 논문집
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• 제13권2호
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• pp.75-83
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• 2017

In severe accident conditions of light water reactors, the loss of coolant may cause problems in integrity of zirconium fuel cladding. Under the condition of the loss of coolant, the zirconium fuel cladding can be exposed to high temperature steam and reacted with them by producing of hydrogen, which is caused by the failure in oxidation resistance of zirconium cladding materials during the loss of coolant accident scenarios. In order to avoid these problems, we develop a multi-metallic layered composite (MMLC) fuel cladding which compromises between the neutronic advantages of zirconium-based alloys and the accident-tolerance of non-zirconium-based metallic materials. Cold pilgering process is a common tube manufacturing process, which is complex material forming operation in highly non-steady state, where the materials undergo a long series of deformation resulting in both diameter and thickness reduction. During the cold pilgering process, MMLC claddings need to reduce the outside diameter and wall thickness. However, multi-layers of the tube are expected to occur different deformation processes because each layer has different mechanical properties. To improve the utilization of the pilgering process, 3-dimensional computational analyses have been made using a finite element modeling technique. We also analyze the dimensional change, strain and stress distribution at MMLC tube by considering the behavior of rolls such as stroke rate and feed rate.

• 대한임상검사과학회지
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• 제36권1호
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• pp.43-48
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• 2004

Cerebral vasoreactivity is an index of autoregulation of cerebral perfusion, and can be measured using functional images such as Xe CT, SPECT and PET in reponse to hypercapneic stimulus. In order to measure cerebral $CO_2$ vasoreactivity in routine TCD study conveniently and reliably, we devised a method of rebreathing into closed volume of reservoir bag as a hypercapneic stimulus, and applied it to 44 healthy volunteers. As a hypercapneic stimulus, we applied fitting mask connected with closed reservoir bag for about 90 seconds, and mean blood flow velocity(MBFV) and pulsatility index(PI) were evaluated at proximal middle cerebral arteries(MCA) of 50-55 mm depth, before and after the hypercapneic stimulus. Age affected the MFV and PI value showed significant and the MFV was 56.45(SD=9.75)cm/sec, while PI was 0.406(SD=0.089). As age increases the flow velocity decreased significantly whereas PI value increased(P<0.05). The vasoreactvity significantly decreased with age(P<0.05). The decrease of cerebral blood flow quantity and cerebral blood flow velocity is not only because of increase of diameter of cerebrovascular resulting from aging, but the resistance increase of small blood vessel resulting from the increase of PI & RI value is regarded. We suppose that the rebreathing method is a reliable and convenient technique as a hypercapneic stimulus in determining cerebral $CO_2$ vasoreactivity. The rebreathing method could be non-invasive and useful methods in estimation of the cerebrovascular reactivity and could be applied to the basal and follow-up evaluation of the cerebrovascular reserve of the ischemic stroke patients.

• 한국전문물리치료학회지
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• 제19권2호
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• pp.69-79
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• 2012

Importance of the work-related musculoskeletal disorders (WMSDs) has been increasing in the hospital industry such as health care industry and financial industry. This study investigated in order to identify the factors like general, occupational and ergonomically characteristics of the subjects related to musculoskeletal disorders (MSDs) of physical therapists (PTs). Ergonomic tools of rapid upper limb assessment (RULA) were used for evaluation workload of the tasks. Prevalence of MSDs were 13 PTs (26.0%) for neck, 31 PTs (62.0%) for shoulder, 9 PTs (18.0%) for arm/elbow, 27 PTs (54.0%) for hand/wrist, 28 PTs (56.0%) for back, 14 PTs (28.0%) for leg/foot. The analysis of the rate of the pain intensity showed that 53.5% subjects experience moderate pain and 14.0% subjects experience severe pain. Factors which were general characteristics, for example, height, ergonomically characteristics such as 'Posture Score A' were related musculoskeletal subjective symptoms in logistic analysis (p<.05). Among physical therapists, action level of RULA were action level 2 (6.0%), action level 3 (52.0%), action level 4 (42.0%). Physical therapists were estimated one of the highest risk factor in this study. This study suggested that the need of preventive education and program for PTs (physical therapists). Comprehensive and systematic management plans should be established to include both ergonomic and sociopsychological aspects.

• 대한조선학회논문집
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• 제56권5호
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• pp.418-426
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• 2019

To derive a simplified analytic solution which can be utilized as a fundamental solution for the wave maker design, a segment of the wave board has been idealized as a submerged line segment in a two dimensional domain of a wave flume. The lower end of the line segment could be located at arbitrary depth of the wave flume and the upper end of the board could be also submerged to any depth from the free surface. The freely oscillating motion of the wave board is assumed to be defined by determining the condition of horizontal oscillation on both ends differently. The submerged wave board oscillating in horizontal direction could be specified by selecting the amplitude, frequency and the phase lag differently on lower and upper ends of the board. The simplified two dimensional wave generated by the wave board segment has been obtained by the first order perturbation method. It is found that the general solution of the freely oscillating wave board in two dimensional domain could be decomposed into the solution of flap motion with lower end hinge and swing motion with upper end hinge. The case study of the analytic solutions has been carried out to evaluate the effect on the wave height due to the difference of oscillation frequency, phase difference and variation of stroke between for the motion of both ends. It is found that the solution of the freely oscillating wave board could be utilized for the development of high performance wavemaker especially for irregular waves.

• 소성∙가공
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• 제24권1호
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• pp.37-43
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• 2015

The purpose of the current study is to improve the clinching joint strength of aluminum and fiber metal laminates (FMLs) comprised of three layers. The joining of FML and Al 5052 by a conventional clinching joint has some disadvantages such as necking of the upper sheet, lack of interlocking, defects caused by the vertical load, and especially loss of strength of the composite material due to the low ductility. In the current study, a tapered-hole clinching method is proposed as an alternative for the joining of Al 5052 and FMLs. A hole with a tapered shape is formed before the joining process. The design parameters were evaluated using the Taguchi method for the geometry of the tapered hole in order to determine the maximum separation load. The diameter of the punch corner, clearance, punch stroke and the tapered length were used as the main variables in the Taguchi method. In conclusion, the contribution ratio for each of the fours variable examined was 35.07%, 22.44%, 21.32% and 14.11%, respectively. In addition, the appropriate combination of the design parameters can make a 5% improvement in the vertical direction joint strength.

• 한국지능시스템학회논문지
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• 제17권7호
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• pp.924-929
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• 2007

영상에 나타나는 자막은 영상과 관계가 있는 정보를 포함한다. 이러한 영상과 관련 있는 정보를 이용하기 위해 영상으로부터 자막을 추출하는 연구는 근래에 들어 활발히 진행되고 있다. 기존의 연구는 일정한 높이의 자막이나 획의 두께를 지닌 자막에서만 정상적인 작동을 한다. 본 논문에서는 일정 크기 이상의 자막에 대해서 적용할 수 있는 크기에 무관한 자막 추출 방법을 제안한다. 먼저, 자막 연결 객체의 패턴 추출을 위해서 자막이 포함된 영상을 수집하고, 신경망을 이용해서 자막의 패턴을 분석한다. 그 후로는 사전에 추출한 패턴을 이용하여 입력 영상에서 자막을 추출한다. 실험에 사용된 영상은 뉴스, 다큐멘터리, 쇼 프로그램과 같은 대중 방송에서 수집하였다. 실험 결과는 다양한 크기의 자막을 포함한 영상을 사용하여 실험하였고, 자막 추출의 결과는 찾아진 연결객체 중에 자막의 비율과 자막 중에 찾아진 자막의 비율로 분석하였다. 실험 결과를 보면 제안한 방법에 의해 다양한 크기의 자막을 추출할 수 있음을 보여준다.