• Journal of Magnetics
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• 제5권2호
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• pp.65-71
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• 2000

Although the electromagnetic launcher technology has been progressed significantly during the past two decades the number of firing test facilities are not many. This is prbably due to the large budget and man power required to build and maintain full scale electromagnetic launcher facilities. As the EM launcher technology's potential capabilities have been somewhat demonstrated with the full scale large systems the research is now headed more toward overcoming specific difficulties and answering questions experimentally with smaller, cost effective systems. The first half of this paper presents EM launcher's improved sub-scaling relationships based upon magnetic, thermal and momentum differential equations and EM launcher's basic equations. With the proposed scaling method the field variables can be matched or scaled linearly between the two geometrically scaled systems. The second half of the paper presents pulsed power system's circuit analysis and design technique, which is applied to the capacitor-powered small pulsed power system with crow-barring circuitry. The effect of the so-called speed volt is included. A sub-scaled small system's design is provided as an example.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권4호
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• pp.305-312
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• 2016

Purpose: The purpose of this study is to provide a sensitivity analysis of system reliability for recognizing effectiveness of changing of BD mode failures using reliability growth projection model based on NHPP. Methods: Crow extended reliability projection model (CERPM) is used to analyze the changing of two factors 1) the number of BD mode failures, 2) fix effectiveness factor (FEF) values. Results: The system reliability has increased in accordance with the number of BD mode failures and FEF values have increased. Conclusion: It is necessary to design failure modes and FEF values to supervise the reliability.

• Animal cells and systems
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• 제6권1호
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• pp.81-84
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• 2002

SINE-R retroposons have been derived from human endogenous retrovirus HERV-K family and found to be hominoid specific. Both SINE-R retroposons and HERV_K family are potentially capable of affecting the expression of closely located genes. Using the genomic DNA from patients with schizophrenia, we identified 26 SINE-R retroposons and analyzed them with the sequences derived from the hominoid primates. The SINE-R retroposons from schizophrenia showed 89.7-96.6％ sequence similarities with the sequence of the schizo-cDNA clone that derived from postmortem tissue from the frontal cortex of an individual suffering from schizophrenial. Phylogenetic analysis using the neighbor-joining method revealed that the new SINE-R retroposons in schizophrenia have proliferated independently during hominid evolution. Such retroposons have great relevance to genomic change connected to human diseases. The data suggest that new SINE-R retroposons identified in schizophrenia deserve further investigation as potential leads on the understanding of neuropsychiatric diseases.

• Journal of the Optical Society of Korea
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• 제14권4호
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• pp.438-443
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• 2010

In this paper, behaviors of photonic crystal (PC) radiative structures and antenna arrays have been compared for two types of uniform and binomial excitations. Appropriate duality has been shown between them. These results can be generalized to other types of excitation and arrangement of photonic crystal radiative arrays such as linear, planar and circular arrays of three dimensional (3D) photonic crystal termination resonators. Using these results in designing photonic circuits has some advantages for shaping a particular radiative beam at the photonic crystal exit, for instance reducing the divergence angle of the main lobe in order to enhance the directivity, for better coupling, or for splitting the emitted beam, for dividing the output beam to the next devices in photonic integrated circuits (PIC). For analysis and simulation of the photonic crystal structures, the finite difference time domain (FDTD) method has been employed.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 춘계학술대회 논문집
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• pp.39-43
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• 2002

A new model for heat transfer and thermal deformation analysis according to strip mm in coiling process has been proposed. Finite difference analyses for heat transfer of cold rolled coil have been carried out under various coiling tensions and strip crown using the equivalent thermal conductivity for the radial direction of cold rolled coil which is a function of strip thickness, surface characteristics and compressive pressure. The compressive pressure is calculated from a equation expressed as a function of hoop stress and coil tension considering strip mm obtained by experiment. Finite element method for thermal deformation of cold rolled coil has been performed to investigate the effects of the strip crown, the coil tension and temperature. From these analyses, it is found that the axial inhomogeneity of thermal deformation is increased as the strip crown, compressive pressure, and temperature drop in cold coiled strip increase.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.537-540
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• 1988

This paper presents a new shadow testing acceleration scheme for ray tracing called hybrid shadow testing(HST), based on conditional switching between the conventional shadow testing method and Crow's shadow volume method, with the object polygons as well as the shadow polygons registered onto the corresponding cells under the 3-D space subdivision environment. Despite the preprocessing time for the generation and registration of the shadow polygons, the total shadow testing time of the new algorithm was approximately 50 % of that of the conventional shadow testing method for several examples while the total ray tracing time was typically reduced by 30% from the conventional approach.

• Journal of Life Science
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• 제10권2호
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• pp.12-13
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• 2000

A human-specific retroposon SINE-R.C2 has been derived from a human endogenous retrovirus HER V-K 10. It is absent in the genome of nonhuman primates and present within the third intron of the human C2 gene that is located in the class III region of the major histocompatibility complex. In the present study, we determined the regional location of the human C2 gene. The analysis of the Genebridge 4 radiation hybrid mapping panel using PCR amplification located the C2 gene between D6S1422 (10.1 cR) and CHLC.GATA4A03 (21.3) with a lod score of>3.0. This allowed us to localize C2 gene on the human chromosome 6 band p21.31.

• Coupled systems mechanics
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• 제13권1호
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• pp.1-19
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• 2024

The effectiveness of coupling with a bolted rim is assessed in this research using a newly designed optimization algorithm. The current study, which is provided here, evaluates 10 contemporary metaheuristic approaches for enhancing the coupling with bolted rim design problem. The algorithms used are particle swarm optimization (PSO), crow search algorithm (CSA), enhanced honeybee mating optimization (EHBMO), Harmony search algorithm (HSA), Krill heard algorithm (KHA), Pattern search algorithm (PSA), Charged system search algorithm (CSSA), Salp swarm algorithm (SSA), Big bang big crunch optimization (B-BBBCO), Gradient based Algorithm (GBA). The contribution of the paper isto optimize the coupling with bolted rim problem by comparing these 10 algorithms and to find which algorithm gives the best optimized result. These algorithm's performance is evaluated statistically and subjectively.

• 한국산학기술학회논문지
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• 제18권6호
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• pp.269-276
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• 2017

본 연구는 MTS와 스피루리나 함유 화장품이 40~50대 중년여성의 피부 톤, 피부보습 및 색소침착, 미세주름 개선 등 피부에 미치는 영향을 알아보고 효과적인 피부 관리 방법을 제시하고자 실험을 진행하였다. 실험 방법은 MTS, 스피루리나 불 포함 세럼과 크림 팩을 사용한 8명의 대조군과 MTS, 스피루리나 함유 세럼과 크림 팩을 사용한 8명의 실험군으로 분류하였으며, 실험은 주 1회, 총 6회, 1회 관리 시간은 30분으로 시행하였다. 실험 전 0주, 실험 6주 후, 실험 종료 2주 후로 총 3회에 걸쳐 피부 변화를 측정하였다. 측정 결과, 스피루리나 함유 화장품을 사용한 실험군은 피부톤, 수분이 통계적으로 유의하게 증가하였고(p<0.05), 대 소 색소 침착수, 눈꼬리 주름 면적, 멜라닌, 홍반은 통계적으로 유의하게 감소하였다(p<0.05). 실험 종료 2주 후, 실험 6회 후와 비교하여 관리의 지속성을 본 결과 실험군은 눈꼬리 주름 면적, 멜라닌이 통계적으로 유의하게 감소하였고(p<0.05), 피부 톤에서 피부 밝기, 수분은 통계적으로 유의하게 증가하였다(p<0.05). 실험이 종료된 후에도 지속적으로 피부 밝기, 미세주름, 멜라닌, 수분이 개선된 것을 관찰할 수 있었다. 피부 톤에서 색조 밝기, 채도 밝기, 대 소 색소 침착수, 홍반에서도 두 군 모두 실험 6회 후와 비교하여 실험이 종료된 2주 후에도 효과가 유지됨을 알 수 있었다. 결론적으로 MTS와 스피루리나 불 포함 화장품을 이용한 관리보다 MTS와 스피루리나 함유 화장품을 이용한 관리가 피부 톤, 피부보습 및 색소침착, 미세주름 개선에 변화량의 차이가 큰 것으로 나타났다. 관리 후 피부 상태를 묻는 질문에도 모두 만족한다고 응답하여 MTS와 스피루리나 함유 화장품을 이용한 관리가 중년여성의 노화 피부 개선을 위한 효율적인 피부 관리 프로그램 방법으로 적용이 가능할 것으로 사료된다.

• Nuclear Medicine and Molecular Imaging
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• 제41권1호
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• pp.66-67
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• 2007

POEMS syndrome is a rare disorder, also known as Crow-Fukase, PEP or Takatsuki syndrome. The acronym, POEMS, represents polyneuropathy, organomegaly, endocrinopathy, M protein and skin change. However, there are associated features not included in the acronym such as sclerotic bone lesions, Castleman disease, papilledema, thromobocytosis, peripheral edema, ascites, effusion, polycythemia, fatigue and clubbing. In most cases, osseous lesions in POEMS syndrome present as an isolated sclerotic deposit and that reveal as osteosclerotic myeloma. Several cases of $^{18}F-FDG$ PET in multiple myeloma involvements were reported, but there was no previous literature that reported FDG PET findings in POEMS syndrome. We describe here a 66-year-old patient with POEMS syndrome who underwent $^{18}F-FDG$ PET/CT image.