• 제목/요약/키워드: length scales

검색결과 299건 처리시간 0.024초

고분자 자기조립 구조의 전산 모사: 원자 모델로부터 메조 스케일 모델까지 (Simulations of Self-Assembled Structures in Macromolecular Systems: from Atomistic Model to Mesoscopic Model)

  • 허준;조원호
    • 폴리머
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    • 제30권6호
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    • pp.453-463
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    • 2006
  • 분자 모델에 의한 전산 모사는 단백질 접힘, 미셀화, 블록공중합체의 규칙구조화 등 다양한 고분자 계의 자기조립 현상을 예측하거나 그 조립 메커니즘을 밝히는 데 특별히 유용한 연구방법이다. 자기조립 현상은 분자 수, 분자 크기 등, 계의 속성에 따라 나노미터 이하의 현상으로부터 마이크론이나 그 이상의 길이 스케일의 현상까지 조립 구조의 길이 스케일이 매우 광범위하기 때문에 다양한 계의 모든 조립 현상을 양자역학적 방법과 같은 궁극의 근본원칙에 의해 모사하는 것은 현실적인 시간 내에서 불가능하다. 이러한 문제들을 해결하기 위해 계를 기술하는 과정에서 필요 이상으로 세밀한 표현을 생략하여 모델을 다른 관점에서 재구성하는 방법이 있는데 재구성된 모델은 그 관점에 따라 크게 '원자 수준'의 모델과 '메조 스케일 수준'의 모델로 분류할 수 있다. 본 총론에서는 고분자 자기조립 현상과 관련하여 이 두 가지 관점에 따른 모델과 모사 방법들에 대해 살펴보고자 한다.

Size Korea 2004의 한국인 인체치수를 이용한 남성용 밀착 팬츠 패턴 개발 (Pattern Development of Tight-fitting Pants for Men Using Measurements of Size Korea 2004)

  • 정연희
    • 한국생활과학회지
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    • 제15권5호
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    • pp.791-802
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    • 2006
  • The construction of athlete's tight-fitting garments by reducing the elastic knit pattern is an interesting subject, which directly influences the performance of the wearer. Therefore, relationships between the reduction rates of the men's pants pattern obtained using measurements of Size Korea 2004 and clothing fitting were explored to improve clothing comfort. Two pattern making methods were developed and the reduction rates were applied to those pants depending on the parts of human body. The four male subjects were university students in the ages of 20 to 24. Subjective wear sensations of the experimental garments were rated using seven Likert scales during 4 consecutive days. While wearing the garments, subjects were kept four various postures including waist flexion and sitting etc by requests of the researchers. Likert type scale was used for the evaluation and 7 point indicates that it gave the best fit as tight-fitting pants. As results, differences in the length and girth between two piece pants pattern(style 1) and one piece pants pattern(style 2) were 0.0$\sim$0.3cm. Between two pattern making methods, one piece pants pattern(the style 2) was superior to two piece pants pattern in terms of subjective sensation and fit. Among eight tight-fitting pants, C, D, G, H pants were superior in terms of fitting and stability of waist and hip part to the others. ill case of tight-fitting pants, the reduction rate of the pattern in the course direction, the reduction rate of T2/3(66%) was better than that of T/2(50%), but the reduction rate of the pattern in the wale direction, that of the part of crotch, which was very sensitive part, should be kept the same as suggested earlier by Ziegert(1988).

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한국산 기름종개 Cobitis taenia Linne의 연구 3. 횡반B${\cdot}$C형의 형태와 분포 (A STUDY OF KOREAN SPINOUS LOACHES(Cobitis taenia Linne) 3. On the Morphology and Distribution of the Crossband B-type and C-type)

  • 김익수
    • 한국수산과학회지
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    • 제9권3호
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    • pp.209-213
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    • 1976
  • 여러가지 반문형을 가진 기름종개는 우리나라의 어디에나 널리 분포하지만 횡반B형과횡반 C형은 영산강과 섬진강에서만 서식하고 있어 주목된다. 이 2형은 반문과 지리적 분포상 차이를 보이면서도 이들의 체장분포, 아가미뚜껑뒤의 친한 흑갈색의 반점, 골질반의 구조, 비늘의 형태는 동일하다. 그러나 반문, 2차성징, 체장분포 및 비늘의 형태상 특징은 본속 기지종과는 분명희 구별된다. 이것은 지리적 격리에 의하여 생긴 고유한 형태로서 원래 동일종 이었던 것이 오랜 세월이 지남에 따라 한때 연결되었으리라고 추측되는 영산강과 섬진강이 각각 독립되므로 양개체군간에 교배가 불가능하기 때문에 반문의 분화가 생긴 것으로 본다.

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Flow-conditioning of a subsonic wind tunnel to model boundary layer flows

  • Ghazal, Tarek;Chen, Jiaxiang;Aboutabikh, Moustafa;Aboshosha, Haitham;Elgamal, Sameh
    • Wind and Structures
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    • 제30권4호
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    • pp.339-366
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    • 2020
  • This study aims at modeling boundary layers (BLs) encountered in sparse and built environments (i.e. open, suburban and urban) at the subsonic Wind Tunnel (WT) at Ryerson University (RU). This WT has an insignificant turbulence intensity and requires a flow-conditioning system consisting of turbulence generating elements (i.e., spires, roughness blocks, barriers) to achieve proper turbulent characteristics. This system was developed and validated in the current study in three phases. In phase I, several Computational Fluid Dynamic (CFD) simulations of the tunnel with generating elements were conducted to understand the effect of each element on the flow. This led to a preliminary design of the system, in which horizontal barriers (slats) are added to the spires to introduce turbulence at higher levels of the tunnel. This design was revisited in phase II, to specify slat dimensions leading to target BLs encountered by tall buildings. It was found that rougher BLs require deeper slats and, therefore, two-layer slats (one fixed and one movable) were implemented to provide the required range of slat depth to model most BLs. This system only involves slat movement to change the BL, which is very useful for automatic wind tunnel testing of tall buildings. The system was validated in phase III by conducting experimental wind tunnel testingof the system and comparing the resulting flow field with the target BL fields considering two length scales typically used for wind tunnel testing. A very good match was obtained for all wind field characteristics which confirms accuracy of the system.

한국산 환태평양 볼락속(Genus Sebastes), Sebastes glaucus의 최초 보고(쏨뱅이목: 양볼락과) (First Record of the Trans-Pacific Sebastes, S. glaucus(Scorpaeniformes: Scorpaenidae) in the Korean Waters)

  • 정문경;지환성;김진구;이수진;황선재;황강석;박정호
    • 한국어류학회지
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    • 제28권4호
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    • pp.283-286
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    • 2016
  • 쏨뱅이목 양볼락과에 속하는 Sebastes glaucus 1개체(표준체장 276.9 mm)가 독도 북서쪽에서 자망으로 채집되었다. 본 개체는 황갈색 체색, 높은 체고, 전두부와 목덜미 부분은 볼록하고 후두부는 넓다. 또한 14개의 등 지느러미 극조 및 주상악골에 비늘이 없는 것이 특징이다. 우리나라에서 처음 보고되는 환태평양 볼락속인 이 어 류의 국명으로 NFRDI(1999)에 따라 "청회볼락"을 제안한다.

의복설계를 위한 중년여성의 체형별 특징 및 신체만족도 (Body Features and Body Satisfaction of Middle-aged Women for Clothing Design)

  • 김경희
    • 한국의상디자인학회지
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    • 제10권2호
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    • pp.57-68
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    • 2008
  • In this study, we prepared reference data needed for clothing design for middle-aged women by analyzing body satisfaction of their body shape, which had been classified by collecting body features of middle-aged women. As for the study method, we have set five scales from 'never satisfied' to 'very much satisfied,' after analyzing body features of middle-aged women by measuring their body shape through the body meter and auxiliary tools. We used the SPSS 12.0 statistics program, and the results are the following: Body shapes of middle-aged women can be classified into the following four types. A middle-age women with an 'A silhouette' has a normal height, but fat nether limbs. A 'Y silhouette' is short with a fat upper body. The 'O silhouette' is short with fat nether limbs and upper body, and 'H silhouette' is tall and thin. Body shape I has displayed satisfaction with her own body shape, and body shape II showed the most dissatisfaction compared to other body shapes. Body shape III showed satisfaction on all items except face size and breast size, whereas body shape IV was dissatisfied with her face size, neck length, shape of her breast, waist, and buttocks. The result of this study is expected to contribute in accomplishing clothing production that will satisfy the desire of the consumers in the clothing business, while being utilized as the basic data for clothing design that fits their body shape by grasping the changing patterns of their body shape.

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인간에게 친밀한 한글 인식 및 편집 지원시스템 (Human Friendly Recognition and Editing Support System of Korean Language)

  • 손영선
    • 한국지능시스템학회논문지
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    • 제17권4호
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    • pp.494-499
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    • 2007
  • 본 논문에서는 책 또는 논문을 읽을 때 중요한 부분 또는 정리해야 할 부분의 영역을 선택하면, 해당영역의 문자들을 문서편집기에 순차적으로 출력시킴으로써 수정 저장 가능하게 하여 공부한 부분을 정리하는 시스템을 구현하였다. 이 시스템은 사용자가 원하는 영역을 손가락으로 선택하면, 손 인식 알고리즘을 적용하여 손가락 움직임을 검출하여 선택된 영역을 인식한다. 선택된 영역의 가로, 세로 거리를 펄스 수로 변환한 후 모터를 제어하여 그 위치만큼 카메라를 이동시킨다. 문자인식이 가능하도록 줌을 확대/축소하고 조정된 줌에 맞는 초점으로 근접 제어한 후, 더욱 선명한 영상을 얻기 위해 명암차이를 이용하여 미세조정을 하였다. 획득된 영상에 문자인식 알고리즘을 적용하여 문서로 변환시켜서 중요 부분들을 정리케하는 한글 인식 및 편집지원 시스템을 구현하였다

Daily Mean Sea Level and Atmospheric Pressure Along the Coasts of the Northwestern Pacific Ocean

  • Oh, Im-Sang;Moon, Il-Ju;Youn, Yong-Hoon
    • Journal of the korean society of oceanography
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    • 제32권4호
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    • pp.171-180
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    • 1997
  • Daily mean sea level variability and its response to atmospheric pressure along the coasts of the northwestern Pacific Ocean are investigated. Daily values of sea level and atmospheric pressure covering the period 1976-1986 from 72 stations are analyzed. The sea level and the air pressure in all the data set have a definite seasonal signal, and higher frequency oscillations at time scales of several days to several weeks are also observed. Among the short-period oscillations of sea level with periods shorter than six months, the period of around 3 or 4 months is dominant in most study stations. According to the statistical analysis of sea level and air pressure, the length scale of sea level variability is smaller than that of air pressure for the present study area. The overall variability of sea level is found to be the smallest around Hokkaido, Japan and the largest in the China coasts. Large short-period (< 6 months) sea level variability is found in the southern coasts of China and Hokkaido, and large long-period (> 6 months) variability in the southern coasts of Japan and Korea along Tsushima Current and Kuroshio. The patterns of air pressure are very similar to those of sea level. The air pressure field is found to account for 31% of the overall sea level variability in the study area. Conside.ins the fact that the results (40%) of Pang and Oh (1995) were obtained through monthly sea level, the present result implies that the short-period sea level variability is less affected by air pressure. Generally the sea level response to air pressure are found to be isostatic, but significantly nonisostatic for the periods around 4 months and for those of 2 to 4 days. In particular, nonisostatic response for higher frequencies seem to be due to the restrictions to water transport necessary for barometric responsein the Korea Strait.

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DHA 보충이 영아의 적혈구 지방산조성과 두뇌발달에 미치는 영향 (The Effects of DHA-Supplemented Formula on the Fatty Acid Composition of Erythrocyte and Brain Development in Full-Term Infants)

  • 손보경
    • Journal of Nutrition and Health
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    • 제30권5호
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    • pp.478-488
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    • 1997
  • Omega-3 fatty acid, docosahexaenoic acid(DHA) is found in a high proportion in the structural lipids of cell membranes, in particular those of the central nervous system and the retina. Diet-induced changes in fatty acid composition in these tissues may affect physiochemical functions. This study was conducted to investigate whether supplements of DHA in infant formula has an effect on the composition of fatty acids in erythrocytes with regard to brain development. Experimental groups were breastmilk group(n=21), placebo formula group(n=15), and DHA supplemented formula (0.26%) group(n=16). Infants were selected by mothers who deliverecdd at Kyung Hee medical center from February to April, 1996. Infant body weight, length, and head circumference were similar among the experimental groups at 16 weeks of age. The levels of DHA in breastmilk, placebo formula, and DHA supplemented formula were 0.56, 0, and 0.26% of total fatty acids, respectively. There was a significant correlation between dietary DHA intake and erythrocyte DHA levels. The levels of arachidonic acid did not differ among the three expermental groups. The result of flash visual evoke potential(VEP) test was correlated with the erythrocyte levels and dietary DHA levels at 16 weeks of age. No other fatty acid was correlated with VEP test results. No differences were found in Bayley Mental and Psychomotor Development Index scores among the three groups at 20 weeks of age. DHA seems to be an essential nutrient for optimum growth and maturation of term infants. Relatively small amounts of dietary DHA supplementation significantly elevate DHA supplementation significantly elevate DHA content in erythrocytes, which in turn has an implication for better scores for infant's VEP test. Whether supplementation of formula-fed infants with DHA has long-term benefits remains to be elucidated.

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인제군 내린천의 포트홀 지형 분석 (Analysis on pothole landforms at Naerin River in Inje-gun)

  • 이광률;김대식;김창환
    • 한국지형학회지
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    • 제19권2호
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    • pp.113-122
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    • 2012
  • 본 연구는 강원도 DMZ 지오파크의 지오사이트를 발굴하기 위하여, 인제군 내린천의 포트홀을 대상으로 지형 특성을 분석하였다. 내린천의 P1, P2 지역은 유수의 방향을 따라 고랑형 와지인 퍼로우형 포트홀이 주로 나타나고, P3 지역은 퍼로우형 포트홀이 밀집된 구역과 여러 유형의 포트홀이 산재된 구역이 구분되며, P4 지역은 여러 유형의 소규모 포트홀이 산재되어 있다. 총 44개 포트홀을 계측한 결과, 단면이 U자형인 포트홀, 유향과 일치하는 방향성을 가진 포트홀, 내부에 자갈이 퇴적되어 있는 포트홀 등이 길이, 폭, 깊이, 경사도에서 모두 큰 값을 보이는 것으로 나타났다. 내린천의 P1, P2 지역은 포트홀의 규모와 형태가 매우 특징적이며 경관이 아름답기 때문에 지오사이트로 개발하기 양호한 곳으로 판단된다.