• 한국해양공학회지
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• 제30권4호
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• pp.294-302
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• 2016

Because of the importance of steel material saving and rational ship structural design due to the rapid increase in steel prices, a ship structural design system was developed for plate members reinforced by doubler plates subjected to biaxial in-plane compressive loads. This paper mainly emphasizes the design system improvement and upgrade according to the change in the in-plane loading condition of the doubler plate from the single load discussed in a previous paper to the biaxial in-plane compressive load discussed in this paper. A direct design process by a structural designer was added to this developed optimized system to increase the design efficiency and provide a way of directly inserting a designer's decisions into the design system process. As the second stage of preliminary steps of doubler design system development, design formulas subjected to these biaxial loads used in the doubler plate design system were suggested. Based on the introduction of influence coefficients $K_t_c$, $K_t_d$, $K_b_d$ and $K_a_d$ based on the variations in the doubler length, breadth, doubler thickness, and average corrosion thickness of the main plate reinforced by the doubler plate, respectively, the design formulas for the equivalent plate thickness of the main plate reinforced by the doubler plate were also developed, and a hybrid design system using these formulas was suggested for the doubler plate of a ship structure subjected to a biaxial in-plane compressive load. Using this developed design system for a main plate reinforced by a doubler plate was expected to result in a more rational reinforced doubler plate design considering the efficient reinforcement of ship plate members subjected to these biaxial loads. Additionally, a more detail structural analysis through local strength evaluations will be performed to verify the efficiency of the optimum structural design for a plate member reinforced by a doubler plate.

• Steel and Composite Structures
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• 제38권6호
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• pp.739-749
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• 2021

This paper introduces an improved design equation to evaluate the resisting capacity of circular reinforced concrete (RC) columns partially strengthened with outer steel tube. When RC column members are required to be strengthened according to the change in the loadings considered and/or the deterioration progress in columns, wrapping up RC column with steel circular tube, which takes the form of concrete filled steel tube (CFST), has been popularly considered because of its structural advantage induced from the confinement effect. However, the relatively high construction cost of steel tube is restricting its use to the required region, while deriving the shape of a partial CFST column. To evaluate the resisting capacity of a partial CFST column, numerical analyses need to be performed, and a numerical model proposed in the previous study for the numerical analysis of full CFST columns is used to conduct parametric studies for the introduction of a design equation. The bond-slip effect developed along the interface between the in-filled concrete and the exterior steel tube is taken into consideration and the validity of the numerical model has been established through correlation studies between experimental data and numerical results for partial CFST circular columns. Moreover, parametric studies make it possible to introduce a design equation for determining the optimum length of outer steel tube which produces partial CFST circular columns.

• 대한조선학회 특별논문집
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• 대한조선학회 2013년도 특별논문집
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• pp.8-12
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• 2013

DNV crane criteria are specially designated for the vessel equipped with lifting crane to cover the risk during the crane operation. Based on the DNV crane criteria, the crane performance shall be decided. The weight control has great importance in the management of vessel's design for crane vessel. To evaluate limitation of lightship weight and the effect of design changes sufficiently, the lightship allowable VCG curve was used. The optimization process was carried out for generation of the lightship allowable VCG curve due to the difficulty coming from the characteristic of DNV crane criteria. This paper includes the introduction to the DNV Crane criteria and optimization process for evaluation in aspect of lightship weight and VCG.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1857-1861
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• 2003

This paper proposes a method for controlling energy distribution to 1 phase induction heating coil by using the Binary Rate Modulation (BRM) Technique. Such method provides proper frequency to the heating coil's requirement by control the frequency at the resonance point, that is, 64-kHZ frequency band. System design are classified to 2 parts. The first part determines main frequency , and the second part generates the frequency from the 8-bit BRM derived from IC no. PAL22V10 in order to control the frequency for Full-bridge connected inverter when supplying the energy required by the 1 phase induction heating coil. Therefore, efficiency of the energy supply can be increate.

• 한국의류산업학회지
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• 제12권4호
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• pp.508-512
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• 2010

To study the development trends of domestic apparel design, we analyzed patent applications that were applied to the field of apparel design. It was presumed that economic and social environment have affected directly on the number of apparel design applications. Since year 2000, the whole number of apparel design applications has shown a remarkably increasing tendency, but depending on the items, the trends of patent applications have different tendency. While the number of applications regarding western costume such as a jacket, pants, suit and coat has been increasing from mid 2000s, the number of applications regarding Hanbok and undergarments have been decreasing from mid 2000s. In early 2000s, there were a lot of applications relating to design creation due to combination of color and form in apparel design. However, from mid 2000s, variety of techniques such as granting functional characteristics, asymmetry construction, introduction of various textiles, techniques of draping were being applied in design creation.

• 국제초고층학회논문집
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• 제11권4호
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• pp.265-276
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• 2022

Double-Skin Facades (DSF) on tall buildings are becoming increasingly common in urban environments due to their ability to provide architectural merit, passive design, acoustic control and even improved structural efficiency. This study aims to understand the effects of porous DSF on the aerodynamic characteristics of tall buildings using wind tunnel tests. High Frequency Force Balance and pressure tests were performed on the CAARC standard tall building model with a variable porous DSF on the windward face. The introduction of a porous DSF did not adversely affect the overall mean forces and moments experienced by the building, with few differences compared to the standard tall building model. There was also minimal variation between the results for the three porosities tested: 50%, 65% and 80%. The presence of a full-height porous DSF was shown to effectively reduce the mean and fluctuating wind pressure on the side face of the building by about 10%, and a porous DSF over the lower half height of the building was almost as effective. This indicates that the porous DSF could be used to reduce the design load on cladding and fixtures on the side faces of tall buildings, where most damage to facades typically occurs.

• 한국건설관리학회논문집
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• 제7권1호
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• pp.128-137
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• 2006

최근 들어 설계VE의 역할 및 중요성은 날로 부각되고 있으므로 업무를 효율적으로 수행할 수 있는 방안에 관한 연구가 요구된다. 하지만 국내에는 설계VE가 도입 된지 얼마 되지 않아 연구 활동이 미진한 측면이 많다. 이에 본 연구에서는 설계VE 업무의 효율화를 위한 수행 기준을 제시하고자 한다. 그 방법은 설계VE 업무 수행과정에서 발생되고 있는 다수의 문제 요인을 도출하는 것으로 1차적으로 VE 전문가 교육의 팀 프로젝트 사례를 분석하고, 2차적으로 교육을 이수한 각 분야별 전문가를 대상으로 팀 프로젝트 진행과정에서 발생된 문제 요인을 설문조사를 통해 분석하는 것이다. 그리고 분석된 내용을 기반으로 설계VE 업무 효율화를 위한 중점 관리 요인을 제시하고 그에 따른 업무 효율 최적화 방안 및 절차를 제안하고자 한다.

• 공학기술논문지
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• 제11권4호
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• pp.287-294
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• 2018

Since its introduction in Korea, design VE has widely been used as a means to enhance values in the construction industry. However, a greater emphasis is still placed on cost reduction in approach attitudes and performance evaluations on the implementation of design VE. In this regard, this study presented a performance evaluation method for cost, function, and value of VE proposals. Numerical criteria on the increase and decrease of cost and function that can classify the value enhancement type of VE proposals were proposed based on the performance evaluation method. It is expected that the use of numerical criteria for the type classification of VE proposal, and cost and performance evaluation method proposed in this study will make it possible to conduct a clear and more intuitive evaluation of VE proposal. However, it is appropriate to use the numerical criteria as a guideline to apply the new performance evaluation method for VE proposals. Therefore, it is necessary to conduct a statistical analysis with a wider range of users after the repeated application of the findings of this study, and thus to carry out research for presenting the numerical criteria for various types of users.

• 한국생산제조학회지
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• 제25권1호
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• pp.21-29
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• 2016

To overcome the large ring gear manufacturing problems seen in slewing bearings and girth gears, pin gear drive units have been developed. Among them, a novel slewing bearing with an internal pinwheel gear set (i-PGS) is introduced in this paper. First, we consider the exact cam pinion profile of i-PGS with the introduction of a profile shift coefficient. Furthermore, a new root relief profile modification for the i-PGS cam pinion is presented. Then, the contact stresses are investigated to determine the characteristics of the surface fatigue by varying the shape design parameters. The results show that the contact stresses of i-PGS can be reduced significantly by increasing the profile shift coefficient. In addition, the contact ratio, a measure of teeth overlapping action, decreases with the decrease of the allowable pressure angle.

• 한국CDE학회논문집
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• 제12권2호
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• pp.126-136
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• 2007

Teleconferences have been used in business sectors to reduce traveling costs. Traditionally, specialized telephones that enabled multiparty conversations were used. With the introduction of high speed networks, we now have high definition videos that add more realism in the presence of counterparts who could be thousands of miles away. This paper presents a new technology that adds even more realism by telecommunicating with hand gestures. This technology is part of a teleconference system named SMS (Smart Meeting Space). In SMS, a person can use hand gestures to manipulate meeting data that could be in the form of text, audio, video or 3D shapes. Fer detecting hand gestures, a machine learning algorithm called SVM (Support Vector Machine) has been used. For the prototype system, a 3D interaction environment has been implemented with $OpenGL^{TM}$, where a 3D human skull model can be grasped and moved in 6-DOF during a remote conversation between distant persons.