• 제목/요약/키워드: gradient ideal

검색결과 42건 처리시간 0.024초

Analysis of Characteristics of Spent Fuels on Long-Term Dry Storage Condition

  • Yoon, Suji;Park, Kwangheon;Yun, Hyungju
    • 방사성폐기물학회지
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    • 제19권2호
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    • pp.205-214
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    • 2021
  • Currently, the interim storage pools of spent fuels in South Korea are expected to become saturated from 2024. It is required to prepare an operation plan of a domestic dry storage facility during a long-term period, with the researches on safety evaluation methods. This study modified the FRAPCON code to predict the spent fuel integrity evaluation such as the axial cladding temperature, the hoop stress and hydrogen distribution in dry storage. The cladding temperature in dry storage was calculated using the COBRA-SFS code with the burnup information which was calculated using the FRAPCON code. The hoop stress was calculated using the ideal gas equation with spent fuel information such as rod internal pressure. Numerical analysis method was used to calculate the degree of hydrogen diffusion according to the hydrogen concentration and temperature distribution during a dry storage period. Before 50 years of dry storage, the cladding temperature and hoop stress decreased rapidly. However, after 50 years, they decreased gradually and the cladding temperature was below 400 K. The initial temperature distribution and hydrogen concentration showed a parabolic line, but hydrogen was transferred by the hydrogen concentration and temperature gradient over time.

CMA-ES/SPGD 이중 알고리즘을 통한 결맞음 빔 결합 시스템 위상제어 및 동작성능에 대한 전산모사 분석 (Hybrid CMA-ES/SPGD Algorithm for Phase Control of a Coherent Beam Combining System and its Performance Analysis by Numerical Simulations)

  • 여민수;김한솔;정윤찬
    • 한국광학회지
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    • 제34권1호
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    • pp.1-12
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    • 2023
  • 본 연구에서는 다채널 결맞음 빔결합 시스템을 위한 위상제어 방식으로 covariant matrix adaption evolution strategy (CMA-ES) 알고리즘 및 stochastic parallel gradient descent (SPGD) 알고리즘을 결합한 이중 위상제어 알고리즘을 제안하고 그 동작 특성을 전산모사를 통해 분석한다. 제안하는 CMA-ES/SPGD 이중 위상제어 알고리즘은 결합된 최종 출력광 세기가 미리 설정된 특정값에 도달하기 전까지는 그 위상제어 최적화를 CMA-ES 알고리즘을 통해 진행하고, 그 이후에는 SPGD 알고리즘으로 전환하여 진행하는 순차적 이중 구조를 취한다. 이를 이상적인 7채널과 19채널 광섬유 결합기 기반 결맞음 빔결함 시스템에 적용하였을 때, 위상제어 최적화 평균 수렴시간이 기존의 SPGD 알고리즘만 단독적용한 경우에 비해 약 10% 단축됨을 확인하였다. 뿐만 아니라, 동일한 결맞음 빔결함 시스템에서 실제 환경과 유사하게 각 채널광에 위상잡음을 부가적으로 인가한 경우, 본 연구에서 제안하는 이중 위상제어 알고리즘을 적용할 경우 주어진 조건에서 그 평균 수렴시간이 기존의 SPGD 알고리즘만 단독적용한 경우에 비해 7채널 시스템의 경우 약 17%, 19채널 시스템의 경우 약 16-27% 정도 단축됨을 확인하였다. 본 연구에서 제안한 CMA-ES/SPGD 이중 위상제어 알고리즘은 향후 실제 대기 환경과 같이 위상잡음 효과를 무시할 수 없는 조건에서 결맞음 빔결합을 구현시 매우 유용하게 활용될 수 있을 것으로 기대된다.

20대 성인 여성의 드롭치에 따른 체형 분류 및 브래지어 컵 사이즈 변화 연구 (The Study of Body Type According to Drop Value of Women in Their 20's and Gradient of Brassiere Cup Size)

  • 정진아;최혜선;최정욱
    • 한국의류학회지
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    • 제38권6호
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    • pp.887-895
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    • 2014
  • The study provides baseline data on developing ready-to-wear clothes for adult females in their twenties who have finished shaping their bodies and have realized an ideal shape. We analyzed the data from females aged from 20 to 29 in "The $5^{th}$ Size Korea Survey" and "The $6^{th}$ Size Korea Survey", and sorted body shapes into several types according to drop values before analyzing and comparing the characteristics among groups. We also referred to the change by year in the size of upper inner wear. To classify body shapes, three drop values were assigned for bust girth - waist girth, hip girth - waist girth, hip girth - bust girth; through cluster analysis all data were classified into three body types. Type 1 is more like normal body shapes with small drop values at the bust girth - waist girth and well-build lower body. Type 2 is X-shaped body shaped like a fiddle with big drop values at all parts. Type 3 is Y-shaped body with a big drop value at the bust girth - waist girth and well-build upper body. Type 2, X-shaped body, has the majority of distribution in every year, which proved to be the most idealistic body shape. There was a change in the brassiere cup size. Korean ladies in their twenties have larger breasts. The body shapes of Korean females in their twenties are increasingly like those of westerners. Bust girth is a very critical element to set measurements and design patterns for upper wear; consequently, a change in the size of breasts should be considered.

Analysis of Organic Components and Osteoinductivity in Autogenous Tooth Bone Graft Material

  • Kim, Young-Kyun;Lee, Junho;Kim, Kyung-Wook;Um, In-Woong;Murata, Masaru;Ito, Katsutoshi
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제35권6호
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    • pp.353-359
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    • 2013
  • Purpose: Extensive research is actively ongoing for development of an ideal bone substitute that meets the gold standard. Tooth was selected as a donor site for evaluation of potentials in bone substitutes based on its similar chemical compositions to alveolar bone. Previous studies have evaluated inorganic components of autogenous tooth bone graft material (AutoBT) and osteoconductivity. In continuation from the previous studies, the current study was conducted for analysis of organic components and evaluation of osteoinductivity of AutoBT. Methods: Forty-six extracted teeth were collected from actual patients (Korea Tooth Bank, R&D Institute). Extracted teeth were processed into AutoBT and implanted in dorsal subcutaneous muscular tissues of 15 athymic mice. Biopsy samples were harvested at two, five, and eight weeks. The Bradford assay, sodium dodecyl sulphate polyacrylamide gradient gel, and western blotting were performed for investigation of organic contents of AutoBT. Results: Histology analyses showed signs of new bone formation as early as two weeks. Results of the Bradford assay indicated the existence of noncollagenous proteins (NCP). 0.29% (2.89 mg/g) of proteins were extracted by weight in the root portion of AutoBT; 0.02% (0.029 mg/g) and 1.79% (17.93 mg/g) of proteins were measured by weight in crown and block-form of AutoBT, respectively. However, recombinant human bone morphogenetic protein-2 was not observed in AutoBT. Conclusion: Within the limitation of the current study, AutoBT induced new bone formation by NCP embedded in dentin.

p-Version 유한요소법에 의한 형상 최적화설계 (Shape Optimal Design by P-version of Finite Element Method)

  • 김행준;우광성
    • 대한토목학회논문집
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    • 제14권4호
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    • pp.729-740
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    • 1994
  • h-version 유한요소법에 근거를 둔 형상최적화 설계에서는 초기모델의 기하형상에 대한 이상적인 체눈설계가 최종해석시에는 적합하지 않을 수 있게 된다. 그러므로, 최적화의 반복단계마다 모델의 단변형상에 대한 새로운 체눈설계가 필요하게 된다. 그러나 p-version 유한요소법은 형상최적화 문제 해석을 위한 매우 매력적인 대안으로 제시될 수 있다 p-version 유한요소법은 h-version 유한요소법과 비교하여 다음과 같은 큰 장점을 갖고 있다. 첫째로, 보간함수의 차수가 3차이상이 되면 요소의 찌그러진 형상에 대한 유한요소 해에 별 영향을 미치지 않는다. 둘째로, 심지어 응력특이 문제도 h-version에 비해 p-version은 적절한 체눈설계를 하게되면 훨씬 효율적이다. 셋째로, 초지 체눈설계와 최종 체눈설계가 동일하므로 반복단계마다 새롭게 체눈설계를 할 필요가 없어진다. Bezier의 곡선보간법, 경사투사법과 적분형 르장드르 다항식에 기초를 둔 2차원 형상최적화를 위한 p-version 모델이 제시되었다. 수치해석 경과는 p-version 소프트웨어인 RASNA를 사용하여 수행되었다.

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심장판막 질환 성형술에 대한 임상적 고찰 (Reconstructive Procedures Combined with or Without Prosthetic Valve Replacement for Cardiac Valvular Lesions)

  • 김윤;조범구;홍승록
    • Journal of Chest Surgery
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    • 제9권2호
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    • pp.207-214
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    • 1976
  • Operations for cardiac valvular disease has been progressed in various ways. Since 1949 when Lord Russel operated mitral stenosis by closed technique at Johns Hopkins Hospital then much progress has been achieved and that nowadays severely diseased cardiac valve has been replaced by prosthetic valve, which is almost ideal in hemodynamic aspect, but still it has many problems such as thromboembolism, destruction of red blood cell, pressure gradient, and disturbance of left ventricular function, so in case of delicate situations, valve replacement should be decided carefully. Besides prosthetic valve, there are some kinds of reconstructive procedures and these have been resulted in better prognosis than prosthetic valve replacement in selected cases. So, authors have reviewed 61 Cases of cardiac patients who have been operated reconstructive valvular surgery by cardiopulmonary bypass, at Yonsei University, from Jan. 1963 to Mar. 1976. Out of 61 cases, 9 patients were replaced by prosthetic valve and rest of the patients were operated upon in various reconstructive procedures such as commissurotomy, valvotomy, valvuloplasty, and annuloplasty. Twenty cases of congenital heart diseases with valvular lesion, which had been operated for valvular lesion were also included in this statistics. Out of 9 cases of prosthetic valvular replacement five cases of prosthetic valvular replacement was done combined with other reconstructive procedures after attempted valvuloplasty. Comparative prognosis of both procedures are somewhat variable by reporters, average 19% of mortality after reconstructive surgery and 38% of mortality after prosthetic valve replacement in long term results. Most common cause of death in postoperative period was low output syndrome in both cases. It seems that good preoperative evaluation and proper reconstructive surgery will afford good prognosis in selected cardiac valvular diseased patient.

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FDS를 이용한 특별피난계단 부속실 제연설비의 방연풍속 기류특성 (Characteristics of Air Egress Velocity in Vestibule Pressurization System Using the Fire Dynamics Simulator)

  • 류성호;이수경;홍대화;최금란
    • 한국화재소방학회논문지
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    • 제24권6호
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    • pp.153-159
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    • 2010
  • 본 연구는 국내 고층건물 특별피난계단 부속실에 급기가압 제연시스템이 설치되어 있음에도 불구하고 화재 발생 시 피난을 위하여 출입문이 개방되었을 경우 형성되는 방연풍속의 기류가 거실 방향으로 정상적으로 형성되지 않고 부속실로 역류되는 사실을 설치 현장의 실측과 CFD기반 시뮬레이션을 통하여 확인하였다. 그 내용을 보면 방연풍속의 기류 특성은 부속실의 면적이 작을 경우 심하게 출입문 상부로 기류가 역류되었다. 시뮬레이션 결과 급기댐퍼의 날개각도가 45도 상향인 경우는 출입문 하단부에 일부 역기류 현상이 발생하였지만 상단부에서는 기류분포가 양호하였다. 부속실 면적이 $4m^2$인 경우는 출입문에서 거실방향으로 정상적인 기류 분포를 보였다. 이러한 상황에서 부속실 면적이 작게 설계될 경우 성능위주 설계를 실시하여야 한다.

PCR 방법을 이용한 우유 및 유제품에서 발생하는 식중독 균의 신속 검출법 (Rapid Detection Methods for Food-Borne Pathogens in Dairy Products by Polymerase Chain Reaction)

  • 곽혜림;한선경;김이슬;홍연;김해영
    • Journal of Dairy Science and Biotechnology
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    • 제31권2호
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    • pp.171-177
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    • 2013
  • The dairy industry has consistently grown via the expansion of dairy-based food categories. Dairy product consumption is stable since the nutrient composition in dairy products is ideal for human health. However, dairy products are highly susceptible to food-borne pathogens. Controlling the safety of dairy products is thus important when considering the nutrient-rich matrix of this food category. Currently, immunoassays or molecular biology techniques have been used to evaluate the safety of dairy products in Korea. These methods are based on the detection of proteins and thus have low reproducibility and sensitivity. Recent techniques to detect food-borne pathogens have focused on genetic analyses. Rapid detection methods for food-borne pathogens in milk and dairy products using polymerase chain reaction (PCR) techniques, such as conventional PCR, real-time PCR, repetitive sequence-based (rep)-PCR, PCR-denaturing gradient gel electrophoresis (DGGE), and digital PCR, are reviewed in this article. The aim of this review was to contribute knowledge of the relationship between microflora and the quality of dairy products. This study will also assist in the immediate monitoring of food-borne pathogens in milk and dairy products when an outbreak related to this food category occurs.

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복합재 평판의 두께변화가 램파의 전파에 미치는 영향 (The effects of the thickness variation on the propagation of Lamb waves in a composite plate)

  • 한정호;김천곤
    • 한국항공우주학회지
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    • 제34권6호
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    • pp.29-34
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    • 2006
  • 본 연구는 두께변화가 있는 복합소재 평판을 전파하는 램파의 전파특성을 실험을 통하여 살펴보았다. 상용 항공우주구조물에는 두께변화가 존재하는 부품이 많이 사용되고 있고 구조변화에 의해 두께가 변할 수도 있기 때문에 구조건전성 모니터링을 위하여 램파를 사용하고자 한다면, 이러한 구조물에 대한 램파의 특성을 면밀히 분석해 볼 필요가 있다. 본 연구는 얇은 두께의 PZT를 구조물 표면에 부착하여 실험을 수행하였다. 두께변화가 있는 전파경로를 선택하여 측정된 신호의 전파속도 및 주파수 분석 결과를 이상적 전파조건과 비교를 통하여 두께변화가 존재하는 영역에서 전파특성의 변화가 이루어지는 과정 중에 전이영역이 발생함을 제시하였다.

New Protein Extraction/Solubilization Protocol for Gel-based Proteomics of Rat (Female) Whole Brain and Brain Regions

  • Hirano, Misato;Rakwal, Randeep;Shibato, Junko;Agrawal, Ganesh Kumar;Jwa, Nam-Soo;Iwahashi, Hitoshi;Masuo, Yoshinori
    • Molecules and Cells
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    • 제22권1호
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    • pp.119-125
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    • 2006
  • The rat is an accepted model for studying human psychiatric/neurological disorders. We provide a protocol for total soluble protein extraction using trichloroacetic acid/acetone (TCA/A) from rat (female) whole brain, 10 brain regions and the pituitary gland, and show that two-dimensional gel electrophoresis (2-DGE) using precast immobilized pH (4-7) gradient (IPG) strip gels (13 cm) in the first dimension yields clean silver nitrate stained protein profiles. Though TCA/A precipitation may not be "ideal", the important choice here is the selection of an appropriate lysis buffer (LB) for solubilizing precipitated proteins. Our results reveal enrichment of protein spots by use of individual brain regions rather than whole brain, as well as the presence of differentially expressed spots in their proteomes. Thus individual brain regions provide improved protein coverage and are better suited for differential protein detection. Moreover, using a phosphoprotein-specific dye, ingel detection of phosphoproteins was demonstrated. Representative high-resolution silver nitrate stained proteome profiles of rat whole brain total soluble protein are presented. Shortcomings apart (failure to separate membrane proteins), gel-based proteomics remains a viable option, and 2-DGE is the method of choice for generating high-resolution proteome maps of rat brain and brain regions.