• The Journal of Asian Finance, Economics and Business
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• 제7권1호
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• pp.101-110
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• 2020

Energy and energy consumption play an important role in strategies for socio-economic development of the country. In 1995, Vietnam officially entered the 500 kV North-South transmission power line exploits, with a full length of 1,487 km. The purpose of this study is to investigate the breakpoint and the transition effect of energy consumption to economic growth in Vietnam during the period of 1980-1994, and 1995-2016. The Autoregressive Distributed Lag (ARDL) approach and the Bounds test are used to test for the presence of cointegration, whereas the Toda and Yamamoto procedure Granger causality test is used for the direction of causality. The result of the Bounds test validates the existence of cointegration among the included variables. The empirical results provide evidence that energy consumption has a positive impact on the economic growth of Vietnam in the long run. The causality test shows that there is bi-directional causality between energy consumption and economic growth, supported feedback hypothesis. There is a breakpoint in 1995 and the contribution of energy consumption in economic growth in the period of 1995-2016 is lower than the stage 1980-1994. This study suggests Government authorities explore new sources of energy to achieve sustainable economic development in the long run.

• Structural Engineering and Mechanics
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• 제20권3호
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• pp.313-334
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• 2005

The paper presents a new approach for the analysis of slope stability that is based on the numerical solution of a differential equation, which describes the thrust force distribution within the potential sliding mass. It is based on the evaluation of the thrust force value at the endpoint of the slip line. A coupled approximation of the slip and thrust lines is applied. The model is based on subdivision of the sliding mass into slices that are normal to the slip line and the equilibrium differential equation is obtained as the slice width approaches zero. Opposed to common iterative limit equilibrium procedures the present method is straightforward and gives an estimate of slope stability at the value of the safety factor prescribed in advance by standard requirements. Considering the location of the thrust line within the soil mass above the trial slip line eliminates the possible development of a tensile thrust force in the stable and critical states of the slope. The location of the upper boundary point of the thrust line is determined by the equilibrium of the upper triangular slice. The method can be applied to any smooth shape of a slip line, i.e., to a slip line without break points. An approximation of the slip and thrust lines by quadratic parabolas is used in the numerical examples for a series of slopes.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.698-705
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• 2004

Application of structural load on soft ground can cause lateral movement as well as ground break due to pressing and shearing of ground. Especially, abutment supported by pile foundation can make pile deformed due to lateral movement of ground in order to have harmful effect on structure. According to the result of this study, it is required to consider disturbance of weak soil layer when using lateral movement countermeasure method by EPS construction method as a result of performing study on safety review and EPS construction method with respect to this based on site where lateral movement occurs due to backside soil filling load at bridge abutment installed on weak ground, and it is required to sufficiently consider soil reduction during design of EPS construction method due to lateral movement deformation of soft clay layer by losing ground horizontal resistance force due to plasticity of ground around pile as well as combination part damage with pile head and expansion foundation.

• Journal of Mechanical Science and Technology
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• 제17권9호
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• pp.1380-1387
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• 2003

When a cold HPSI (High pressure Safety Injection) fluid associated with an overcooling transient, such as SGTR (Steam Generator Tube Rupture), MSLB (Main Steam Line Break) etc., enters the cold legs of a stagnated primary coolant loop, thermal stratification phenomena will arise due to incomplete mixing. If the stratified flow enters the downcomer of the reactor pressure vessel, severe thermal stresses are created in a radiation embrittled vessel wall by local overcooling. As general thermal-hydraulic system analysis codes cannot properly predict the thermal stratification phenomena, RG 1.154 requires that a detailed thermal-mixing analysis of PTS (pressurized Thermal Shock) evaluation be performed. Also. previous PTS studies have assumed that the thermal stratification phenomena generated in the stagnated loop side of a partially stagnated primary coolant loop are neutralized in the vessel downcomer by the strong flow from the unstagnated loop. On the basis of these reasons, this paper focuses on the development of a 3-dimensional thermal-mixing analysis model using PHOENICS code which can be applied to both partial and total loop stagnated cases. In addition, this paper verifies the fact that, for partial loop stagnated cases, the cold plume generated in the vessel downcomer due to the thermal stratification phenomena of the stagnated loop is almost neutralized by the strong flow of the unstagnated loop but is not fully eliminated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1743-1746
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• 2003

Automated Container Terminals have been being developed over the world for many recent years and more and more countries get interested in it because the amount of containers exported or imported is steeply increasing. Existed Container Terminals were not designed to control this kind of heavily many containers. They would face many structural problems soon or later, although they have managed to do well until now. One of the most important things in developing Automated Container Terminal is to develop the equipment able to transfer the awfully many containers. Those are maybe Automated Transfer Cranes, Automated Guided Vehicles, and Automated Quay-Side Cranes. The word "Automated" means the equipment is operated without drivers and those equipments are able to work without taking any break. Through the researches on the existed transfer cranes, authors decided that the structure of existed transfer cranes is not proper to swift and fast transfer and it′s not impossible to handle so many containers in limited time. Therefore authors have been studying on the proper structure of the Automated Container Crane for past several years and a new type of transfer crane has been developed. Design concepts and control methods of a new crane will be introduced in this paper.

• 펄프종이기술
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• 제37권4호통권112호
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• pp.32-37
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• 2005

To Increase the productivity of a paper machine, the maximization of the machine speed is a kind of simple way As the machine speed increases, more intense wet pressing is required to persist the outlet consistency of press part and reduce the water removal of dryer part. With more intense pressing, there are concerns that the quality of paper will be affected. This study was carried out to evaluate the influence of wet-pressing on internal structure of paper, The nip pressure at the first and third nip in triple nip press was controlled. Paper structures, strength properties and pore properties were evaluated. As a result, first nip pressure more strongly influenced the paper structural properties than third nip pressure in triple nip pressing condition. Because of the high water content and low wet-web strength of paper web in first nip, increasing the first nip pressure induced the incipient crushing of wet-web and then caused a potential of web break during the following coating or printing processes.

• 재무관리연구
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• 제26권1호
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• pp.221-263
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• 2009

This paper studies the behaviour of stock prices on the ex-dividend day in the Korean stock market. Since a majority of listed Korean firms are December firms whose fiscal year end in December and whose ex-dividend day falls on the same calendar day in the year, we use stock prices of Non-December firms to estimate the general stock price movements not related to cash dividends. We estimate excess returns on days around the ex-dividend day. Our major findings are (a) there is no tax clientele effect in Korea, (b) the opening price stock prices fell by the amount of the current cash dividend per share until 2001, but it does not fall as much as the current dividend per share since 2001. Furthermore, in contrast to the U.S. and the Japanese findings, (c) stocks earned negative excess returns on the ex-dividend day until 2001, after which all stocks are earning positive excess returns on the ex-dividend day, and (d) the closing stock price on the ex-dividend day that used to be even higher than the cum-dividend price until 2001 is lower than the opening stock price since 2001. The evidence suggests a structural break has happened around the year 2001.

• Nuclear Engineering and Technology
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• 제48권5호
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• pp.1264-1272
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• 2016

The accurate estimation of leak rate through cracks is crucial in applying the leak before break (LBB) concept to pipeline design in nuclear power plants. Because of its importance, several programs were developed based on the several proposed flow models, and used in nuclear power industries. As the flow models were developed for a homogeneous pipe material, however, some difficulties were encountered in estimating leak rates for bimaterial pipes. In this paper, a flow model is proposed to estimate leak rate in bimaterial pipes based on the modified Henry-Fauske flow model. In the new flow model, different crack morphology parameters can be considered in two parts of a flow path. In addition, based on the proposed flow model, a program was developed to estimate leak rate for a crack with linearly varying cross-sectional area. Using the program, leak rates were calculated for through-thickness cracks with constant or linearly varying cross-sectional areas in a bimaterial pipe. The leak rate results were then compared and discussed in comparison with the results for a homogeneous pipe. The effects of the crack morphology parameters and the variation in cross-sectional area on the leak rate were examined and discussed.

• 국제초고층학회논문집
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• 제9권1호
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• pp.53-60
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• 2020

"A practical architect might not unnaturally conceive the idea of erecting a vast edifice whose frame should be entirely of iron, and clothing the frame--preserving it--by means of a casing of stone…that shell must be regarded only as an envelope, having no function other than supporting itself..." --Viollet-le-Duc, 1868. Viollet-le-Duc's recipe for an encased iron frame foresaw the separation of structural and enclosing functions into discrete systems. This separation is an essential characteristic of skyscrapers today, but at the time of his writing cast iron's brittle nature meant that iron frames could not, on their own, resist lateral forces in tall structures. Instead, tall buildings had to be braced with masonry shear walls, which often also served as environmental enclosure. The commercial availability of steel after the 1880s allowed for self-braced metal frames while parallel advances in glass and terra cotta allowed exterior walls to achieve vanishingly thin proportions. Two Chicago buildings by D.H. Burnham & Co. were the first to match a frame "entirely of iron" with an "envelope" supporting only itself. The Reliance Building (1895) was the first of these, but the Fisher Building (1896) more fully exploited this new constructive typology, eschewing brick entirely, to become the first "building without walls," a break with millennia of tall construction reliant upon masonry

• Structural Engineering and Mechanics
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• 제66권1호
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• pp.37-43
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• 2018

In orthopedic surgery and in particular in total hip arthroplasty, the implant fixation is carried out using a surgical cement called polymethylmethacrylat (PMMA). This cement has to insure a good adhesion between implant and bone and a good load distribution to the bone. By its fragile nature, the cement can easily break when it is subjected to a high stress gradient by presenting a craze zone in the vicinity of inclusion. The focus of this study is to analyze the effect of inclusion in some zone of cement in which the loading condition can lead to the crack opening leading to their propagation and consequently the aseptic loosening of the THR. In this study, the fracture behavior of the bone cement including a strange body (bone remain) from which the onset of a crack is supposed. The effect of loading condition, the geometry, the presence of both crack and inclusion on the stress distribution and the fracture behavior of the cement. Results show that the highest stresses are located around the sharp tip of bony inclusion. Most critical cracks are located in the middle of the cement mantle when they are subjected to one leg standing state loading during walking.