• 제목/요약/키워드: Free-form

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정밀한 FCP 제작을 위한 콘크리트 압출 방식 연구 (A Study on the Concrete Extrusion Method for Precision FCP Fabrication)

  • 김혜권;김지혜;김성진;이동훈
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2023년도 가을학술발표대회논문집
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    • pp.133-134
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    • 2023
  • Free-form buildings have a curved shape and are composed of geometric shapes, which require high precision. Therefore, this study proposed a new extrusion method, a piston method, that improves the precision of FCP by automatically extruding a predetermined amount of concrete by improving the aforementioned limitations. The technology to extrude a predetermined amount of concrete by applying pistons is expected to shorten construction period and increase economic efficiency by improving the precision and productivity of free-form panels.

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A Comparison of the Intestinal Absorption of Amino Acids in Piglets When Provided in Free Form or as a Dipeptide

  • Li, Defa;Zhao, X.H.;Yang, T.B.;Johnson, E.W.;Thacker, P.A.
    • Asian-Australasian Journal of Animal Sciences
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    • 제12권6호
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    • pp.939-943
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    • 1999
  • Three 28 day-old $Duroc{\times}Large$ $White{\times}Landrace$ litter mate gilts weighing an average of 6.5 kg were used to study the intestinal absorption of amino acids when provided in dipeptide form or in the form of a free amino acid mixture. The pigs were given one of three treatments. The control involved a duodenal infusion containing no amino-acids (phosphate buffer plus 5% sorbitol) while the remaining two treatments involved either a duodenal infusion containing a glycine-lysine dipeptide (1 g) or a mixture of the free amino acids glycine and lysine at the same concentration as in the dipeptide. Blood was drawn from a cannula inserted in the portal vein, at 5 to 20 minute intervals, for two hours following infusion. The concentration of intact dipeptide as well as free glycine and lysine in the portal blood was determined by high performance liquid chromatography. The intact dipeptide was never detected in the portal blood at any time after infusion. Lysine appeared in the portal blood more rapidly after infusion of dipeptide than after infusion of free lysine and the concentration of lysine in portal blood was higher in the pig infused with the dipeptide than after infusion of free lysine at almost all time points measured. The cumulative absorption of lysine and glycine from the intestine during the two hour period after infusion was greater in the pig infused with dipeptide than in the pig infused with free amino acids. The results suggest that although intact dipeptide did not reach he portal circulation, a special transport mechanism for absorption of dipeptide by intestinal cells appears to be present in pigs similar to that observed in other species.

Analytic solution for flat-plate under a free surface with finite depth effects

  • Sakir Bal
    • Ocean Systems Engineering
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    • 제14권3호
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    • pp.301-314
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    • 2024
  • In this study, the lift coefficient and wave deformations for a two-dimensional flat-plate in non-cavitating condition were computed using a closed-form (analytic) solution. This plate moves at a constant speed beneath a free surface in water of finite depth. The model represents the flat-plate using a lumped vortex element within the constraints of potential flow theory. The kinematic and dynamic free surface conditions were combined and linearized. This linearized free surface condition was then applied to get the total velocity potential. The method of images was utilized to account for the effects of finite depth in the calculations. The lift coefficient of the flat-plate and wave elevations on the free surface were calculated using the closed-form solution. The lift coefficients derived from the present analytic solution were validated by comparing them with Plotkin's method in the case of deep water. Wave elevations were also compared with those obtained from a numerical method. A comprehensive discussion on the impact of Froude number, submergence depth of flat-plate from the calm free surface, the angle of attack and the depths of finite bottom on the results - namely, lift coefficients and free surface deformations - is provided.

허혈심근 Xanthine Oxidase 의 전환에 관한 연구 (Conversion of Myocardial Xanthine Oxidase in Ischemic Heart of Rat)

  • 박창권
    • Journal of Chest Surgery
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    • 제21권5호
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    • pp.803-815
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    • 1988
  • The present experiments were performed to confirm the hypothesis that xanthine oxidase[XOD], as a source and mechanism of oxygen radical production, plays an important role in the genesis of the reperfusion injury of ischemic myocardium. The experimental ischemic-reperfusion injury was induced in isolated, Langendorff preparations of rat hearts by 60 min. Of global ischemia with aortic clamping followed by 20 min. of reperfusion with oxygenated Krebs-Henseleit solution[pH 7.4, 37*C]. The results were as follows: 1. The releases of creatine phosphokinase and a lipid peroxidation product, malondialdehyde[MDA] into the coronary effluent were abruptly increased upon reperfusion of ischemic hearts. The increases of the enzyme and MDA were suppressed significantly in the hearts removed from rats pretreated with allopurinol, a specific XOD inhibitor[20mg/kg, oral, 24 hrs and 2 hrs before study]. This effect of allopurinol was comparable to that of oxygen radical scavengers, superoxide dismutase[5, 000U] and catalase[12, 500 U]. 2. The increased SOD-inhibitable reduction of ferricytochrome C, which was infused to the hearts starting with reperfusion, was significantly suppressed in allopurinol pretreated hearts. 3. Activities of myocardial XOD were compared in the normal control hearts and the ischemic ones. Total enzyme activities were not different in both hearts. However, comparing with the control, the ischemic ones showed higher activity in 0-form and lower activities in D-form and D/O-form. 4. In the ischemic hearts, phenylmethylsulfonyl fluoride, a serine protease inhibitor, prevented significantly the increase of 0-form and the decreases of D and D/O-form, while thiol reagents did not affect the changes of the enzyme. 5. The increase of 0-form and the decreases of D and D/0-form were not significant in both calcium-free perfused and pimozide, a calmodulin inhibitor, treated ischemic hearts. 6. The SOD-inhibitable reduction of ferricytochrome C were suppressed by PMSF and pimozide treatment as well as by calcium-free perfusion. It is suggested from these results that in the ischemic rat myocardium, xanthine oxidase is converted to oxygen radical producing 0-form by calcium, calmodulin-dependent proteolysis and plays a contributing role in the genesis of ischemic-reperfusion injury by producing oxygen free radicals.

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Mock-up 부재제작을 통한 비정형 건축 외장부재의 제작 문제점 분석 및 개선방안에 관한 연구 (A Study on the Problem Analysis and Quality Improvement in Fabricating Free-Form Buildings Facade Panels through Mock-up Panels Production)

  • 권순호;심현우;옥종호
    • 한국건설관리학회논문집
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    • 제12권3호
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    • pp.11-21
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    • 2011
  • 비정형 건축물은 건축가의 디자인 의도를 반영한 다양한 형태의 외장 디자인을 포함한다. 이러한 비정형 형태의 외장부재는 NURBS (Non-Uniform Rational B-Spline) 라 불리는 이 방향 곡률로 구성된 불규칙한 자유곡선면을 포함하고 있어 실제 외장부재의 생산 및 시공을 위해서는 3차원 비정형 BIM 기술을 적용한 패널최적화 단계를 거쳐야 한다. 본 연구에서는 역공학(Reverse Engineering) 기법을 근간으로 사례연구를 통해 비정형 건축물 BIM 도구인 디지털 프로젝트를 활용하여 패널형태를 구축하고 패널 최적화 결과를 도출한다. 최적화 결과 도출된 비정형 패널부재의 곡률 형상에 따른 Mock-Up 패널제작을 통해 패널종류에 따른 제작 용이성을 테스트하고 레이저 스케닝 기술을 사용하여 설계한 패널과 생산된 패널과의 데이터를 비교함으로써 이방향 곡률 곡면부재의 제작정밀도를 분석한다. Mock-Up 부재 제작 시 전문가 인터뷰를 통하여 국내에서 수행되고 있는 현행 비정형 외장부재 생산방식의 문제점을 도출하고 개선방안을 제시한다.

영화 <여자, 정혜>에 연출된 자유간접화법의 의미 분석 (A Study on Free Indirect Discourse Emerged in the )

  • 김종완
    • 한국콘텐츠학회논문지
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    • 제17권9호
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    • pp.60-68
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    • 2017
  • 필자는 이 논문을 통해 현대영화의 자유간접화법의 형식들을 파악하고자 한다. 우선 자유간접화법과 관련한 개념 정립을 위해 바흐친의 화자와 인물의 목소리의 혼합이라는 다음성 이론을 살펴보았다. 그러나 다음성 이론을 영화에 적용하기 위해서는 소설과 영화의 형식적 차이를 간과할 수 없으며, 이에 필자는 필자의 선행 연구인 서사 거리(narrative distance) 개념에 기초하여 영화 저작도구인 카메라의 이중적 위치에서 영화의 자유간접화법의 가능성을 찾으려 한다. 이어서 필자는 들뢰즈가 "시네마II"에서 주창한 시간 개념을 도입하여 영화의 자유간접화법의 의미를 분석하였다. 즉, 들뢰즈에게서 시간은 과거와 현재의 순환이며 비유크리트적 공간처럼 시간도 순환한다고 본다. 이런 들뢰즈의 크리스털 이미지로서의 시간 개념을 영화 <여자, 정혜>의 분석 도구로 원용하여 영화 속 자유간접화법의 형식들을 이해하고자 한다.

Design and Optimization for the Windowless Target of the China Nuclear Waste Transmutation Reactor

  • Cheng, Desheng;Wang, Weihua;Yang, Shijun;Deng, Haifei;Wang, Rongfei;Wang, Binjun
    • Nuclear Engineering and Technology
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    • 제48권2호
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    • pp.360-367
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    • 2016
  • A windowless spallation target can provide a neutron source and maintain neutron chain reaction for a subcritical reactor, and is a key component of China's nuclear waste transmutation of coupling accelerator and subcritical reactor. The main issue of the windowless target design is to form a stable and controllable free surface that can ensure that energy spectrum distribution is acquired for the neutron physical design when the high energy proton beam beats the lead-bismuth eutectic in the spallation target area. In this study, morphology and flow characteristics of the free surface of the windowless target were analyzed through the volume of fluid model using computational fluid dynamics simulation, and the results show that the outlet cross section size of the target is the key to form a stable and controllable free surface, as well as the outlet with an arc transition. The optimization parameter of the target design, in which the radius of outlet cross section is $60{\pm}1mm$, is verified to form a stable and controllable free surface and to reduce the formation of air bubbles. This work can function as a reference for carrying out engineering design of windowless target and for verification experiments.

발산형 바닥 경사 생성항의 재검토와 체적-수위 관계의 수정 (Review on the divergence form for bed slope source term and correction of the volume/free-surface relationship)

  • 황승용
    • 한국수자원학회논문집
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    • 제50권5호
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    • pp.289-302
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    • 2017
  • 발산형 바닥 경사 생성항(DFB, Divergence Form for Bed slope source term)을 엄밀하게 유도하였으며, DFB 중에서 격자의 변에서 평균 수심을 이용하는 mDFB의 오차를 명백하게 입증하였다. 또한, DFB 기법은 바닥 경사 생성항에 대해 정확한 방법임을 밝혔다. 완전히 잠기기 않은 격자에 대한 기존의 체적-수심 관계의 오류를 수정하였으며, C-특성의 충족을 위해 완전히 잠기지 않은 변에 대한 처리가 필요함을 검토하였다. 이 연구를 통해 근사 Riemann 해법으로 천수방정식을 해석할 때 보다 정확한 수단을 제공할 수 있을 것으로 기대한다.

유아용 의류제품의 인체 안전성에 관한 연구(II) -유리 formaldehyde의 유해성과 함량동향- (Safety Studies on the Sanitary Goods for Infant Part2 : Formaldehyde Allergy and the Quantitative Analysis of Infant's Clothing)

  • 이원자
    • 대한가정학회지
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    • 제33권3호
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    • pp.255-264
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    • 1995
  • This study was the designed to measure skin irritation caused by clothing at free foraldehde have caused a substantial number of cases of dermatitis type. Free formaldehyde levels were observed in infant's sanitatized goods9disposable diapers, cotton-diapers and under wear etc.) at 1992, 1994. The amount of free formaldehyde was measured by means of Acetyle Acetone method(KS K 0611). As the resort, underwear generally gave the highest free formaldehyde level, but disposable diapers and cotton diapers showed the lowest level. The formaldehyde level in intan's clothing lowered in 1994 than 1992, after the enforcement of the level in intant's clothing lowered in 1994 than 1992, after the enforcement of the formaldehyde level control. it was found that 38.7% of infant's sanitatized goods still exceeded th controlled level(A-Ao : 0.05) In the future, research to lower the amount of formaldehyde released form fabrics will also lead to decreased incidence of garment formaldehyde sensitivity. The possibility of a consumer suffering is being in convenienced form a textile-related skin problem will be even lower than it has been in the past.

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On the Hydrodynamic Forces of Oscillating Cylinders in the Presence of a Free Surface

  • Hwang, J.H.;Rhee, K.P.;Hong, S.W.
    • 대한조선학회지
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    • 제17권4호
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    • pp.13-20
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    • 1980
  • The integral equation method to solve the boundary-value problem of a 2-dimensional body oscillating in the presence of a free surface generally breaks down at and near irregular frequencies due to the hypothetical flow inside the body. In this paper singularity distributions were extended to an inner free surface to remove the irregular frequency as Ohmatsu's work in 1978, and the solution for the above problem was found by using stream function. For various bodies including Lewis form cylinders, the hydrodynamic forces were calculated numerically at various wave numbers. From the results we concluded that the irregular frequencies can be removed even for the Lewis form cylinder as Ohmatsu done for circular cylinders, and calculated hydrodynamic forces by the present method are little higher than those of Ohmatsu's when the singularities are put on the inner free surface of the body. We specially point out that the solution for heaving motion converges in an oscillatory manner but not for swaying and rolling motions.

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