• 대한조선학회지
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• 제25권1호
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• pp.3-10
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• 1988

This paper presents some experimental investigations on the effectiveness of the Stern-End-Bulb(SEB) and the design procedure of the optimum one. Experimental method was discussed to search the optimum SEB and the resistance reduction rate was investigated from the resistance test results of the SEB series for a passenger boat and a container ship. The contribution of SEB on the propulsive coefficients was discussed from the self-propulsion test results for a container ship. It would be expected that the power saving rate is about 5.8 percents for a passenger boat and 3.6 percents for a container ship by optimum SEB, respectively.

• 한국IT서비스학회지
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• 제8권1호
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• pp.1-9
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• 2009

It is essential for companies to manage massive data for dealing with large volume of transactions and customers' needs. To this end, the companies have operated data warehouse with many complex tools for data gathering and reporting to the end-users. However, the data from the heterogeneous tools at the various sources cannot be exchanged because of the different interfaces. Therefore, the data cannot be controlled with integrated manner, and furthermore the companies do not focus the quality of data resulting in the data quality problem. Thus, this study suggests how to manage massive data with a metadata. In particular, we investigate current status of metadata management, its appliance, and perspectives. The contribution of this research is to apply the metadata management system to the real world and to suggest its management procedure.

• Steel and Composite Structures
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• 제23권5호
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• pp.493-499
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• 2017

The behaviour of steel frames is highly influenced by the beam-column connections. Traditionally, Steel frames were usually designed assuming that connections are ideally pinned or fully rigid. A semi-rigid connection, however, creates a balance between the two extreme approaches mentioned above. In this research, two full scales of Extended End Plate Connections (EEPCs) were tested. Mathematical and numerical models were used to analyse the connections, and close correlations were found between these models and the corresponding tested specimens, which confirmed the confidence in the experimental results. The experimental results obtained enrich the available test data about behaviour of EEPC. In addition, the purpose of studying EEPC experimentally is to compare the stiffness and moment-rotation curve of EEPCs with that of Cap Plate Connections (CPCs), which were tested in a previous work. CPCs have not been studied sufficiently in the literature. The results obtained show that the typical CPC reduces the connection stiffness and these results will make a valuable contribution to the available test data in the research area of CPC.

• 의정연구
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• 제24권3호
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• pp.55-83
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• 2018

본 논문은 2018년 북한의 비핵화를 위한 협상이 진행되면서 북한이 종전선언 채택을 요구해온 상황과 관련하여 그것이 한국에게 어떤 기회와 위험을 의미하는지를 평가해보기 위한 목적으로 작성되었다. 이를 위하여 평화, 평화체제, 평화협정과 종전선언을 비롯한 개념들을 정리하였고, 북한이 종전선언을 주장해온 경과와 이면의 의도를 평가하였다. 그러고 나서 이러한 종전선언에 합의할 경우 한국에게 어떤 기회의 측면이 가능하고, 어떤 위험의 요소를 우려해야 하는지를 분석하였다. 분석 결과, 종전선언이 채택될 경우 북한의 비핵화에 관한 진전을 기대할 수 있고, 한반도의 평화체제 구축에 기여할 수 있으며, 남북관계에 대한 한국의 명분을강화할 수 있는 기회의 측면이 존재한다고 평가하였다. 반면에, 종전선언이 채택될 경우 유엔군사령부의 해체는 물론이고, 주한미군 철수까지 요구될 수 있으며, 종전선언에 합의한 후 오히려 북한이 비핵화를 중단시킬 우려도 존재하고, 무엇보다 국민들의 대북 경각심이 약화될 위험이 크다고 판단하였다. 따라서 한국은 종전선언의 기회보다는 위험에 더욱 주목하여 신중하게 접근할 필요가 있다.

• Earthquakes and Structures
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• 제6권2호
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• pp.181-199
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• 2014

The infill walls, whose contribution to the earthquake resistance of a structure is generally ignored due to their limited lateral rigidities, constitute a part of the lateral load bearing system of an RC frame structure. A common method for improving the earthquake behavior of RC frame structures is increasing the contribution of the infill walls to the overall lateral rigidity by strengthening them through different techniques. The present study investigates the influence of externally bonded perforated steel plates on the load capacities, rigidities, and ductilities of hollow brick infill walls. For this purpose, a reference (unstrengthened) and twelve strengthened specimens were subjected to monotonic diagonal compression. The experiments indicated that the spacing of the bolts, connecting the plates to the wall, have a more profound effect on the behavior of a brick wall compared to the thickness of the strengthening plates. Furthermore, an increase in the plate thickness was shown to result in a considerable improvement in the behavior of the wall only if the plates are connected to the wall with closely-spaced bolts. This strengthening technique was found to increase the energy absorption capacities of the walls between 4 and 14 times the capacity of the reference wall. The strengthened walls reached ultimate loads 30-160% greater than the reference wall and all strengthened walls remained intact till the end of the test.

• 에너지공학
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• 제25권4호
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• pp.226-235
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• 2016

본고에서는 에너지정책 대응을 위한 기존 계층적 권위를 바탕으로 하는 조정체계에서 벗어나, 중앙정부나 지방정부가 산업계 및 시민단체 등의 다양한 이해관계 주체와 네트워크를 구성한 조정체계로 전환될 수 있도록 정책제언을 제시하고자 한다. 이를 위해서 먼저, 정부의 에너지정책을 위한 조정체계로 전환될 수 있도록 법적 기반의 조성, 둘째로 중앙정부 차원의 에너지정책 거버넌스 구축에 기여, 셋째로 지방정부 차원의 에너지정책 거버넌스 구축에 기여하도록 개선방안을 제시하였다. 따라서 우리나라 에너지정책 거버넌스의 개선을 위한 정책적 방안을 마련하였다. 특히, 여러 에너지정책들이 잘 집행되고 성공할 수 있도록 부처간 의견을 조정하고 협력체계를 구축하기 위한 방안과 정부간 조율된 정책이 민간과 기업의 협력을 통해 잘 집행될 수 있는 체계를 개선하는 데 중점을 두었다.

• 천문학회지
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• 제51권2호
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• pp.37-48
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• 2018

Massive stars blow powerful stellar winds throughout their evolutionary stages from the main sequence to Wolf-Rayet phases. The amount of mechanical energy deposited in the interstellar medium by the wind from a massive star can be comparable to the explosion energy of a core-collapse supernova that detonates at the end of its life. In this study, we estimate the kinetic energy deposition by massive stars in our Galaxy by considering the integrated Galactic initial mass function and modeling the stellar wind luminosity. The mass loss rate and terminal velocity of stellar winds during the main sequence, red supergiant, and Wolf-Rayet stages are estimated by adopting theoretical calculations and observational data published in the literature. We find that the total stellar wind luminosity due to all massive stars in the Galaxy is about ${\mathcal{L}}_w{\approx}1.1{\times}10^{41}erg\;s^{-1}$, which is about 1/4 of the power of supernova explosions, ${\mathcal{L}}_{SN}{\approx}4.8{\times}10^{41}erg\;s^{-1}$. If we assume that ~ 1 - 10 % of the wind luminosity could be converted to Galactic cosmic rays (GCRs) through collisonless shocks such as termination shocks in stellar bubbles and superbubbles, colliding-wind shocks in binaries, and bow-shocks of massive runaway stars, stellar winds might be expected to make a significant contribution to GCR production, though lower than that of supernova remnants.

• 복식
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• 제4권
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• pp.25-37
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• 1981

Art Nouveau style refers to the movement of art which was started in France and Belgium in the last decade of the 19th and the early years of the 20th century. The distinguishing characteristics of Art Nouveau style are the sensous sinuosity of its line, nervously undulating, curving over itself, rhythmical, flowing in endless patterns, which are inspired by animals and plants, specially by flowers, leaves, long stalks. The Art Nouveau style includes also the extreme simplicity of form, and asymmetric design. This new trend of art movement spread into architecture, furniture, wall papers, graphic design, accessories and textiles. In this paper, I tried to find out whether or not the Art Nouveau style had an effect on clothing. Because I believe clothing, like architecture, painting, and sculpture, is an Art form that derives from a particular set of cultural circumstances and reflects the needs and aspirations of the society for which it is created. Fashions in clothing over the last five thousand years have mirrorred the art form as well as the spirit. The result of this study shows that the Art Nouveau style made a lasting contribution to the modernism of clothing as well as architecture and interior design at the end of 19th century and the early years of the 20th century. The modernism of clothing appeared in the straight silhouette, asymmetric design, simple and light trimming, embroidery with Art Nouveau pattern, and stylized flower design in textile. Art Nouveau made a great contribution toward the modern clothing to have its liveliness and its harmonious relationship between clothing design and the use of materials.

• 한국조경학회지
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• 제29권3호
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• pp.29-37
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• 2001

The purpose of this study is to determine the suitable illuminance model of an urban neighborhood park. To this end, 1 dependent variable and 11 independent variables were set, and multiple regression analysis was applied to find correlation between variables and the model. The results of this study are as follows; 1) Among 11 independent variables abstracted to study suitable illuminance model of an urban neighborhood park, as a result of analysis on correlation between suitable illuminance of a dependent variable and activity space by using dummy variables, activity type and illuminance by spaces the suitable illuminance required for an urban neighborhood park was much influenced by activity type, and the fact that the activity was not limited to a specific space. 2) As a result of multiple regression analysis, independent variables influencing the suitable illuminance model of an urban neighborhood park were activity space, illuminance by spaces, seated activity, standing activity, and sporting activity. And, for relative contribution of independent variables to suitable illuminance, activity with sporting showed an importance 22 times higher than seated activity. When the central square(Sp_1) of activity spaces was set to reference category using dummy variables, it showed a contribution 52 times higher than sorting space(Sp_7) and the central square as the most important variable. 3) It was analyzed that suitable illuminance of an urban neighborhood part was most influenced by sporting activity but the relative contribution of a sporting space where activity with sporting occurs was least in view of the function of the space. Very high illuminance is required to accept high activity, and if illuminance at a certain space becomes too high, it may influence the illuminance of other spaces, and may consequently have a negative effect on the suitable illuminance of an urban neighborhood park. The results of this study were mainly for teenagers and young adults in their twenties, so further concrete studies which consider gender and a wider age range are needed in the future. Based on subsequent study, suitable illuminance by spaces shall be suggested.

• Structural Engineering and Mechanics
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• 제4권5호
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• pp.513-527
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• 1996

In this paper, both an approximate expression and an exact expression for the contribution factor of an element to the natural frequency of the finite element discretized system of a structure in general and a membrane in particular have been derived from the energy conservation principle and the finite element formulation of structural eigenvalue problems. The approximate expression for the contribution factor of an element is used to predict and determine the elements to be removed in an iteration since it depends only on the quantities associated with the old system in the iteration. The exact expression for the contribution factor of an element makes it possible to check whether the element is correctly removed at the end of an iteration because it depends on both the old system and the new system in the iteration. Thus, the combined use of the approximate expression and the exact expression allows a considerable number of elements to be removed in a single iteration so that the efficiency of the evolutionary structural optimization method can be greatly improved for solving the natural frequency optimization problem of a structure. A square membrane with different boundary supports has been chosen to investigate the general evolutionary path for the fundamental natural frequency of the structure. The related results indicated that if the objective of a structural optimization is to raise the fundamental natural frequency of the structure to an optimal value, the general evolutionary path during its optimization is that the elements are gradually removed along the direction from the area surrounded by the contour of the highest value to that surrounded by the contour of the lowest value.