• 한국태양에너지학회 논문집
• /
• 제25권4호
• /
• pp.53-60
• /
• 2005

The purpose of this study is to improve energy efficiency of windows in office buildings through the evaluation of their heating, cooling and illumination load. Energy efficiency is influenced by window size which is determined at the early stage of building design. The process of this study is as follows. First, energy performance is analysed according to the various rates of windows through computer simulation (ECOTECT). Then, the annual heating, cooling and illuminating loads according to the different window sizes are compared one another. Results indicated that the optimal window size considering energy efficiency is 50% of the surface area. When the window size is 50% of the surface area, annual maintenance expense is also smallest. Since the cost of cooling is larger than that of heating, too low indoor air temperature in summer is unfavorable based on the reasonable annual maintenance expenses.

• 산경연구논집
• /
• 제6권1호
• /
• pp.37-40
• /
• 2015

Purpose - Investors, creditors, governments, and others make decisions using reasonable information provided by others. In many cases, the users of this information have goals and objectives conflicting with those of the information's producers, indicating the need for external auditors. Research design, data, and methodology - Competition in auditing has noticeably intensified globally, especially in developed countries. This means that auditors are striving to increase the efficiency of their methods. In recent years, risk-based auditing has become prominent among these efforts. In risk-assessment auditing, the auditor may directly affect the effectiveness and efficiency of the audit. Results - As a central framework, the risk assessment process improves audit quality and effectiveness such that the audit will lead to necessary changes. Previous studies have shown that risk assessment affects the nature, timing, and content of audit procedures. Conclusions - In the planning stage of an audit, audit risk assessment may identify any inappropriate or inefficient distribution of resources or determine whether the results of an audit will be ineffective or incorrect. Thus, assessing audit risk is a critical task.

• 대한조선학회논문집
• /
• 제44권5호
• /
• pp.534-541
• /
• 2007

This paper suggests the mathematical method for the estimation of the required engine output for WIG crafts. The engine size of a WIG craft Is a key parameter in the design stage, because WIGs should overcome the hump drag during the take-off. Therefore, it is very important for a WIG designer to estimate required power and state change during take-off. The mathematical method was developed based on the steady planing state model of a planing boat. Through numerical calculations on various take-off states, it was found that the suggested method could give reasonable estimation of required power and state change during take-off.

• Architectural research
• /
• 제7권2호
• /
• pp.13-21
• /
• 2005

Throughout history, buildings have been interrelated with certain indigenous characteristics such as regional climate, culture and religions. In particular, the control of regional climate has been primarily a concern for compatibility with nature. In our modern age, technologies to control climate have been successfully developed in architecture but the consumption of large quantities of natural resources can also produce environmental problems. This study is based on the proposition that this negative trend can be minimized with architectural design that is motivated to coexist with a regional climate. This study develops these design strategies for tall office buildings by analyzing various combinations of building design configurations based on regional climates. The objective is to determine the optimum architecture of tall office buildings during the initial design process that will reduce energy consumption for regional climatic conditions. The eQUEST energy simulating program based on DOE-2.2 was used for this comparative analysis study of the energy use in tall office buildings based on architectural design variables and different regional climates. The results are statistically analyzed and presented in functional architectural design decision-making tables and charts. As a result of the comparison of architectural design consideration for tall office buildings in relation to regional climates, buildings physically need less energy consumption when the architecture is concerned with the regional climate and it produces a more reasonable design methodology. In reality, imbalanced planning which is architectural design's lack of regional characteristics requires additional natural resources to maintain desired comfortable indoor conditions. Therefore, the application of integrated architectural design with regional nature should be the first architectural design stage and this research produces the rational. This architectural design language approach must be a starting point to sustaining long-term planning.

• 국제학술발표논문집
• /
• The 3th International Conference on Construction Engineering and Project Management
• /
• pp.1201-1208
• /
• 2009

A making a decision of construction cost has important meaning and function for both contractor and owner in construction projects. Especially, it should be premised that estimating the construction cost in efficient and rational way in public construction, which is invested by government funds, for efficient execution of the budget and investment as a side of government. The systematic methodology for estimating construction cost approximately of a river facility construction project has not yet been established because of its unique characteristics including its relatively small project size in terms of cost. On this study, It collect and analyze a river facility construction historical cost data for develop an approximate cost estimating model for river applied by typical embankment section method and rate application of the others activity type. And it verify suitability of model through a that result of application of real river facility construction statement at developed model. By this study, it is expected to reasonable and systematic estimating construction cost through application of developed model.

• 디자인학연구
• /
• 제17권3호
• /
• pp.189-198
• /
• 2004

특정 웹사이트의 스타일은 그 사이트가 가지고 있는 성격을 사용자에게 가장 빠르고 정확하게 전달할 수 있는 중요한 방편이다. 또한 보다 효과적인 웹사이트의 구축을 위해서도 그 웹사이트가 대변하는 조직의 특성에 합당한 스타일의 구현은 상당히 중요한 디자인 요소로 볼 수 있다. 이러한 배경을 바탕으로, 본 연구에서는 웹 디자인의 효과적인 기획을 위한 하나의 방편으로서 적절한 스타일 방향을 모색하기 위한 방법 탐색에 관한 연구가 수행되었다. 이를 위해 인터넷 및 문헌연구를 통해 웹 디자인 스타일에 대한 고찰을 시도하였고, 이어서 국내외 여러 웹사이트들의 스타일 유형을 바탕으로 분석을 모색하였다. 또한 그 결과를 기반으로 웹디자인 스타일 유형과 사용자의 심상모델에 관한 설문 조사를 설계 및 수행하고 그 결과를 분석하였다. 금번 연구의 결과로는 일반적인 디자인과정의 스타일 결정과정 단계에서 광범위하게 활용될 수 있는 객관적인 방법의 한 예를 제시하였다는 데 있다. 이는 향후 여러 가지 디자인 분야에서 스타일의 결정 단계에서 본 연구에서 수행된 것과 유사한 방법을 적절히 활용하는 것에서 그 효용성을 찾을 수 있을 것이다.

• 대한조선학회지
• /
• 제4권1호
• /
• pp.59-65
• /
• 1967

Since the screw propellers were adopted as ship propulsion devices, the replacement of propeller shaft due to damage was mostly of fatigue failure due to the alternative stresses [1],[2]. To prevent such a failure, hence, it is suggested that careful attention should be paid to account of the alternative stresses on the design stage of the propeller shafts. In connection with this fact the Ship Classification Societies' Rules are regarded simply as guidance for preliminary determination of the shaft diameter. In this paper, limiting the topic to the small and medium-sized motor ships, an evaluation of the Rules formulae to a theoretical based on Soderberg's correlation [5] between the factor of safety and the resultant stresses obtained by application of the maximum shear theory is done. For this purpose eleven (11) ships built recently in Korea were taken as a species(refer to table 2. in text). In the end the following conclusions are made: (1) In general the Rules formulae give considerably larger size of the propeller shaft diameter than that derived from theoretical calculation, that is, about 7% more in AB and BV Rules, and about 20% more in LR and KR-NK Rules. (2) LR Rule gives the largest size of all, and AB Rule is mostly closed value to the theoretical. (3) The formular of the AB Rule is considered to be of the simplest in utilization and of the reasonable.

• 한국자동차공학회논문집
• /
• 제16권2호
• /
• pp.136-142
• /
• 2008

Thermal management of a junction box of a passenger car has recently become more challenging due to its smaller size and larger current capacity. Thus, it is essential to perform the thermal optimization of a junction box in its design on an early stage of vehicle design. In this study, 3 dimensional CFD simulation with experimental measurement has been done to study for better thermal management of the junction box. First, the study of thermal characteristics of electric relays in the junction box has revealed that each surface of the relay has very different thermal resistance. In addition, an idea to install a cooling fan on the junction box has been studied and it was found that the forced cooling method was not effective on the system to keep the thermal resistance to the reasonable level of the junction box. Finally, the effect of external flows around the junction box on the temperatures of the relays, fuses, etc. has been studied and the result shows that the installation of the junction box at the proper place in an engine room can avoid any unnecessary overdesign in thermal management.

• 한국정밀공학회지
• /
• 제12권9호
• /
• pp.104-114
• /
• 1995

Mathematical models of industrial robots or manipulators are composed of highly nonlinear equations with nonlinear couplings between the variables of motions. These nonlin- earities were not considered important in the first stage that the working speed of the manipulator was not so fast, but the effect of nonlinear forces has become serious, as the working speed has been increased. So more improvement of performance cannot be expected by the control of manipulator using approximate linearization. As an approach for solving these problems, there is a method that eliminates nonlinear theory, which makes possible cecoupling of coupling terms and arbitrary arranging of poles is briefly introduced in this study. When the theory is applied to design the control law, its feasibility is examined whether the reasonable control results are obtained by simulating position, velocity, torque and tracing trajectory. The relations between the coefficients of the linearized differential equations and the maximum error and torque for the prescribed trajectory are also examined. Finally, the method for selecting the values for getting the most rapid and precise response within maximum torque of each drive is suggested in the choice of coefficients of characteristic equations which are obtained as a result of the control.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1997년도 추계학술발표회논문집(1)
• /
• pp.534-539
• /
• 1997

A CHF table method has been assessed in this study for rod bundle CHF predictions. At the conceptual design stage for a new reactor, a general critical heat flux (CHF) prediction method with a wide applicable range and reasonable accuracy is essential to the thermal-hydraulic design and safety analysis. In many aspects, a CHF table method (i.e., the use of a round tube CHF table with appropriate bundle correction factors) can be a promising way to fulfill this need. So the assessment of the CHF table method has been performed with the bundle CHF data relevant to pressurized water reactors (PWRs). For comparison purposes, W-3R and EPRI-1 were also applied to the same data base. Data analysis has been conducted with the subchannel code COBRA-IV-I. The CHF table method shows the best predictions based on the direct substitution method. Improvements of the bundle correction factors, especially for the spacer grid and cold wall effects, are desirable for better predictions. Though the present assessment is somewhat limited in both fuel geometries and operating conditions, the CHF table method clearly shows potential to be a general CHF predictor.