• 대한수학회보
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• 제52권2호
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• pp.367-376
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• 2015

In this paper, we classified finite p-groups G such that $$C_G(x)/<x>$$ is cyclic for all non-central elements $x{\in}G$. This solved a problem proposed By Y. Berkovoch.

• Structural Engineering and Mechanics
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• 제18권2호
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• pp.211-229
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• 2004

The main purpose of this paper is the numerical analysis of the non-linear seismic response of a RC building mock-up. The mock-up is subjected to different synthetic horizontal seismic excitations. The numerical approach is based on a 3D-model involving multilayered shell elements. These elements are composed of several single-layer membranes with various eccentricities. Bending effects are included through these eccentricities. Basic equations are first written for a single membrane element with its own eccentricity and then generalised to the multilayered shell element by superposition. The multilayered shell is considered as a classical shell element : all information about non-linear constitutive relations are investigated at the local scale of each layer, whereas balance and kinematics are checked afterwards at global scale. The non-linear dynamic response of the building is computed with Newmark algorithm. The numerical dynamic results (blind simulations) are considered in the linear and non linear cases and compared with experimental results from shaking table tests. Multilayered shell elements are found to be a promising tool for predictive computations of RC structures behaviour under 3D seismic loadings. This study was part of the CAMUS International Benchmark.

• Structural Engineering and Mechanics
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• 제82권2호
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• pp.205-224
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• 2022

This paper presents a refined finite element formulation for nonlinear static and dynamic analysis of sliding cable structures, overcoming the limitation of the existing approaches that neglect or approximate the friction, pulley dimension, temperature and geometric nonlinearity. A new family of elements with the same framework is proposed, consisting of the cable-pulley (CP) elements considering sliding friction, and the non-sliding cable-pulley (NSCP) elements considering static friction. Thereafter, the complete procedure of static and dynamic analysis using the proposed elements is developed, with the capability of accurately dealing with the friction at each pulley. Several examples are utilized to verify the validity and accuracy of the proposed elements and analysis strategy, and investigate the frictional, thermal and pulley-dimension effects as well. The numerical examples show that the results obtained in this work are in good accordance with the existing works when using the same approximations of friction, pulley dimension and temperature. By avoiding the approximations, the proposed formulation can be effectively adopted in predicting the more precise nonlinear responses of sliding cable structures.

• Steel and Composite Structures
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• 제34권4호
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• pp.487-497
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• 2020

During the last few decades, fluid viscous dampers have been significantly improved in terms of performance and reliability. Viscous dampers dissipate the input energy into heat and the increased temperature may damage internal seals of the damper. As a result, thermal compensation is crucial for almost all fluid viscous dampers. In this study, while referring to the main working principles of the recently developed bypass viscous damper in Iran, a comprehensive case study is conducted on a RC building having diagonal braces equipped with such viscous dampers. Experimental results of a small-scale bypass viscous damper is presented and it is shown that the currently available simplified Maxwell models can simulate behavior of the bypass viscous damper with good accuracy. Using a case study, contribution of bypass viscous dampers to seismic behavior of structural and non-structural elements are investigated. A designed procedure is adopted to increase damping ratio of the building from 3% to 15%. In this way, reductions of 25% and 13% in the required concrete and steel rebar materials have been achieved. From nonlinear time history analyses, it is observed that bypass viscous dampers can greatly improve seismic behavior of structural elements and non-structural elements.

• Journal of the Korean Statistical Society
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• 제26권2호
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• pp.231-243
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• 1997

In this paper we investigate weak convergence of the intergral processes whose index set is the non-compact infinite time interval. Our first goal is to develop the empirical central limit theorem as random elements of [0, .infty.) for an integral process which is constructed from iid variables. In developing the weak convergence as random elements of D[0, .infty.), we will use a result of Ossiander(4) whose proof heavily depends on the total boundedness of the index set. Our next goal is to establish the empirical central limit theorem for the Kaplan-Meier integral process as random elements of D[0, .infty.). In achieving the the goal, we will use the above iid result, a representation of State(6) on the Kaplan-Meier integral, and a lemma on the uniform order of convergence. The first result, in some sense, generalizes the result of empirical central limit therem of Pollard(5) where the process is regarded as random elements of D[-.infty., .infty.] and the sample paths of limiting Gaussian process may jump. The second result generalizes the first result to random censorship model. The later also generalizes one dimensional central limit theorem of Stute(6) to a process version. These results may be used in the nonparametric statistical inference.

• 원예과학기술지
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• 제28권5호
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• pp.836-844
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• 2010

본 연구는 GM 배추와 non-GM 배추 계통간의 식물체 생장 특성, 지방산의 조성 및 무기 영양 성분을 분석하여 GM 작물의 평가를 위한 기초 자료로 이용하고자 실시하였다. GM 배추(SKCP)와 모본(SC) 계통을 중부지역과 북부지역에서 2008년 가을과 2009년 봄과 가을에 밀식 및 일반 배치시험구로 나누어 40일간 재배하고 수확 후 특성을 조사하여 SKCP 계통과 SC 계통간의 차이점 및 재배 지역간의 차이를 분석하였다. 밀식 배치 시험구에서 재배된 배추 식물체의 최외각 엽의 특성 9개 항목에 대하여 조사한 결과, 두 지역에서 재배된 SKCP 계통과 SC 계통간에 통계적 유의차는 두 항목(잎의 모양과 모용수)을 제외하곤 크게 나타나지 않았다. 식물체의 지상부의 특성 6개 항목과 지하부의 특성 3개 항목을 조사한 결과, 두 지역 모두에서 SKCP 계통과 SC 계통간의 통계적 유의차는 거의 나타나지 않았다. 다만, 중륵의 길이가 두 지역에서 계통간 약간의 유의차를 보였으며, 재배 지역간에도 통계적 유의차가 발생하였다. 중부와 북부지역의 일반 배치 시험구의 경우 최외각 잎의 특성을 조사한 결과, 9개의 조사 항목 중 4개의 조사 항목에서 SKCP 계통과 SC 계통간의 통계적 유의차를 보였다. 특히 잎의 길이에서는 계통간, 재배 지역간 그리고 재배 시기별로 변이가 나타나는 것으로 조사되었다. 또한 식물체의 지상부 특성 9개의 조사 항목 중 5개의 항목에서 통계적 유의차가 발생하였으며, 생체중 무게와 중륵의 길이와 넓이에서는 계통간, 지역간 그리고 시기별로 유의차가 크게 나타났다. 2009년도 가을에 중부와 북부 지역의 일반 배치 시험구에서 재배된 배추 식물체의 잎에 존재하는 주된 지방산은 palmitic acid, oleic acid, stearic acid, linoleic acid 및 linolenic acid인 것으로 조사되었다. 5 가지 지방산의 총 함량은 재배 지역 및 식물 계통간에 통계적 유의 차가 없었으나 linolenic acid를 제외한 4가지 지방산은 중부와 북부 지역에서 SKCP 비해 SC 계통이 건중량 1g당 함량이 다소 높은 것으로 조사되었다. 배추 식물체의 잎에 존재하는 무기영양성분의 함량을 조사한 결과, 다량 원소는 질소(N), 인(P), 칼슘(Ca), 칼륨(K), 마그네슘(Mg) 및 나트륨(Na)의 6가지이었고 미량원소는 구리(Cu), 철(Fe), 망간(Mn) 및 아연(Zn)의 4가지로 조사되었다. 무기영양 물질의 대사체 분석 데이터를 표준화 작업하여 스코어를 통해 시각화하여 본 결과, GM 및 non-GM 계통간에 특이적 변이에 따른 클러스터 형성은 확인할 수 없었으나, 지역간 차이에 따른 클러스터 형성은 확인할 수 있었다.

• 대한정형도수물리치료학회지
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• 제27권1호
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• pp.1-11
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• 2021

Background: The purpose of this study is to identify the elements for the construction of the Korean academy of orthopedic manipulative physical therapy's (KAOMPT's) non-face-to-face lecture system using the Delphi method. Methods: The Delphi method was applied to 50 expert panel members of the Central Committee and the Provincial Branch of the KAOMPT. The Delphi survey was conducted in two rounds, and the first Delphi survey collected opinions on 40 questions on 12 topics. The second Delphi survey was collected into 25 questions on 4 topics. As a result of the survey, the content validity ratio (CVR), consensus and convergence were measured. Referring to the number of expert panels and previous studies were determine a CVR of at least 2.29, a consensus of at least .75 and a convergence of 0 to .5. Result: In the first Delphi result, out of the total 40 items, 20 items with high content validity ratio were found, and 10 items found double agreement. In the second Delphi result, 13 out of the total 25 items had a content validity ratio higher than 2.29, and 5 items found a double agreement. Conclusion: This study derived items on the role of central and municipal councils, lecture support and lecture room construction, non-face regular course and special lecture operation and personnel for the establishment of non-face-to-face lecture system. Based on this content, it is expected that it will help establish a non-face-to-face lecture system in 2021 through a pilot non-face-to-face lecture that will be implemented in the future.

• Tribology and Lubricants
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• 제24권6호
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• pp.355-361
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• 2008

In highly stressed machine elements such as angular contact ball bearings and toroidal type traction drives, the elastohydrodynamic lubrication of elliptical contacts with both rolling and spinning motion are occur. In this paper, a finite difference method with non-uniform grid systems and the Newton-Raphson method are applied to solve the problems. Pressure distributions, film contours and variations of the minimum and central film thicknesses are compared with various ellipticity parameter, dimensionless speed and load parameter. The results showed that the spinning motion has significant influence especially on the film shapes. Reduction of the minimum film thickness under spinning is remarkable whereas the central film thickness is relatively less. Especially variations of the minimum film thicknesses with rolling velocity, load and ellipticity ratio are a great different from those of pure rolling. Therefore present numerical scheme can be used in the analysis of general elliptical contact EHL problems and further studies are required.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.90-100
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• 2000

The present paper investigates the elasto-plastic buckling of ball-jointed single layer latticed domes considering the connection characteristics. The domes are composed of tubular member elements, ball joints and connectors. To judge yielding of the member, the ends and central part of tubular member elements are assumed as five elasto-plastic springs. Elasto-plastic buckling load can be identified the yielding load of estimated member As a numerical analysis technique, loading incremental method based on the Newton-Raphson method is used. The effects of connection characteristics are investigated by the following points; (1) the length of rigid zone, (2) looseness of screw, (3) diameter of connector Finally, it is emphasized that the connection characteristics as well as the material non-linearity have significant effects upon the buckling toad of domes.

• Asian-Australasian Journal of Animal Sciences
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• 제12권3호
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• pp.422-428
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• 1999

The mineral status of native goats and forage species, namely; Cynodon plectostachyus, Pennisetum purpureum. Eleusine indica, Cynodon dactylon, Calopogonium muconoides, Centrosema pubescens, Leucaena leococephala, and Mimosa pudica in lahar affected areas of Concepcion, Tarlac, Philippines were determined. Forage and blood samples were collected six times in 1996-97, and analyzed for calcium, phosphorus, magnesium, sulfur, copper, iron, molybdenum, selenium, and zinc. Forage calcium and sulfur are non-limiting. Most species had low phosphorus, copper and selenium, while some had magnesium and zinc levels lower than the critical limit because of low mineral content and high percolation rate of lahar deposits. Iron and molybdenum were in excess. The effect of seasonal variation was observed only in copper, sulfur and iron. Average blood mineral concentration of the animals was above critical limit, but there were no significant differences between seasons. All the animals had plasma phosphorus and magnesium above critical level; but 20 % had low copper, zinc and selenium especially in dry season possibly due to insufficient amount of these elements and excessive molybdenum and iron in most forage. Conversely, calcium in forage was high; but 40 % of the animals had low plasma calcium concentration. Although no clinical signs of mineral deficiencies were observed, supplemental feeding would be important since the condition of the pasture in lahar-laden areas is not expected to improve in the next five years. Intensified use of L. leucocephala with better mineral profile would be ideal.