• Geomechanics and Engineering
• /
• 제15권6호
• /
• pp.1183-1191
• /
• 2018

Reliability analysis is generally regarded as the most appropriate method when uncertainties are taken into account in slope designs. With the help of limit analysis, probability evaluation for three-dimensional rock slope stability was conducted based upon the Mote Carlo method. The nonlinear Hoek-Brown failure criterion was employed to reflect the practical strength characteristics of rock mass. A form of stability factor is used to perform reliability analysis for rock slopes. Results show that the variation of strength uncertainties has significant influence on probability of failure for rock slopes, as well as strength constants. It is found that the relationship between probability of failure and mean safety factor is independent of the magnitudes of input parameters but relative to the variability of variables. Due to the phenomenon, curves displaying this relationship can provide guidance for designers to obtain factor of safety according to required failure probability.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회 2008년도 추계학술대회 및 정기총회
• /
• pp.364-368
• /
• 2008

Recently, necessity of VV & A is also embossed as practical use and importance of M & S are increased in National Defense. The purpose of VV&A is to assure development of correct and valid simulations and to provide simulation users with sufficient information to determine if the simulation can meet their needs. VV&A processes are performed to establish the credibility of the models and simulations. Guidance and Regulation of VV&A are insufficient actual conditions in Korea and example that apply to actuality M&S is state that is hardly. In this paper, VV&A assure its credibility of application VV&A process in Army on the basis of US Organization's application example and provide initial point of VV&A application of National Defense M&S that is developed subsequentness.

• 한국생활과학회지
• /
• 제19권4호
• /
• pp.625-639
• /
• 2010

This study compared male and female university students' perceptions of parenthood and their need for pre-parental educational program. Responses of 579 university students in 5 universities were collected using a questionnaire developed by the researchers. Data were analyzed using a T-test and Pearson's chi squared test. Results showed that (1) systematic and pre-parental education may increase opportunities for university students to prepare parent and child rearing skills. (2) Any pre-parent educational program developed should cover practical and such as communication skills, child-rearing techniques and ways of disciplining children. In this way an educational program could provide university students suitable guidance and give them a positive and proper attitude toward parenting should they become parents in the future.

• 대한안전경영과학회지
• /
• 제17권1호
• /
• pp.215-224
• /
• 2015

International organization and airport operator have issued a guidance manual with regard to the sustainability specialized in airport by adopting environment friendly rating system and developing a variety of sustainable practices. The structure of framework is essential to the development of practical and effective sustainability guideline of airport. Evaluation criteria and method for airport sustainability properly designed is necessary for the assurance of the level of sustainability. In this study, evaluation criteria and method proper to airport after structuring of framework for airport sustainability will be suggested by reviewing a variety of reference documents issued from foreign and domestic organization.

• 한국공작기계학회논문집
• /
• 제17권1호
• /
• pp.150-157
• /
• 2008

Bellows are commonly used in piping systems to absorb expansion and contraction in order to reduce stress. Unlike most piping components, bellows consist of a thin-walled shell of revolution with a corrugated meridian, in order to provide the flexibility needed to absorb mechanical movements. It is a composite shell structure consisting of at least one toroidal shell, an annular plate or conical shell. It is difficult to analyze the behavior of bellows because of its complex geometry. Simplified formulas for variable mechanical behaviors of bellows are provided by a standard called EJMA. An automatic design software for bellows is programming by using VBA(Visual Basic for Application) based on EJMA. Bellows engineers can effectively make a decision for bellows geometries because this software provides graphically design results in its post-processor. Bellows design software is expected to give quite a good guidance to practical design. The characteristics of bellows are also investigated through the automatic design process in bellows design software.

• 한국전자거래학회지
• /
• 제6권2호
• /
• pp.143-157
• /
• 2001

There has been a need for predicting development efforts and costs of the system during the early stage of the software process and hundreds of metrics have been proposed for computer software, but not all provide practical support to the software engineer. Some demand measurement that is too complex, others are so esoteric that few real-world professionals have any hope of understanding them, and others violate the basic intuitive notions of what high-quality software really is. It is worthwhile that metrics should be tailored to best accommodate specific products and processes after grasping their good and no good point. This paper describes two size estimation techniques, the Karner technique and the Marchesi technique, and compares and analyzes them with proposed evaluation criteria. Both techniques are to estimate software size analyzed by use case that is mainly described during the object-oriented analysis phase. We also present an empirical comparison of them, both are applied in the Internet Medicine Prescription System. We also propose some guidance for experiments based on our analysis. We believe that it should be facilitating project management more effective by adjusting software metrics properly.

• Journal of the Optical Society of Korea
• /
• 제20권1호
• /
• pp.174-179
• /
• 2016

In this paper, a novel full-aperture reflective null measuring method is proposed to detect the transmission wavefront of a conformal dome surface. An aspheric compensator is designed and placed behind the dome to reflect the aspheric testing wave back to the same path. To ensure the feasibility of this method, tolerance analysis is conducted, and guidance to assembly is given accordingly. The accuracy of this method is verified to be λ/30 (λ =3.39 μm) by Monte Carlo algorithm. In addition, the influence of different error factors, including the thickness error and decenter error of the dome, on the testing wavefront is analyzed. Simulation and experiment indicate that this method is practical and simple, and can measure the conformal domes precisely and comprehensively.

• 한국물환경학회지
• /
• 제31권1호
• /
• pp.35-41
• /
• 2015

This study focuses on whether a physical habitat model, River2D, is useful to assess and design stream restoration. To achieve the aim, the habitat suitability for Zacco Platypus was analyzed using River2D at midstream of the Anyang-Cheon through modifying the low flow channel and changing the flow discharge. The River2D simulation results show that the inhabited environment for Zacco Platypus is improved by increasing the sinuosity of the low flow channel, and vice versa. Also the inhabited environment for Zacco Platypus gets worse when there is no additional flow for maintenance water supply at the stream flowing through cities. In this respect, the physical habitat simulation study based on the River2D model is useful because it provides a practical guidance in designing stream restoration.

• Journal of international Conference on Electrical Machines and Systems
• /
• 제3권3호
• /
• pp.312-316
• /
• 2014

This paper describes a turnout without movable parts for magnetically levitated vehicles with hybrid magnets, which have been studied by the authors in place of streetcars. Their low construction cost and low maintenance is key to their practical use. Magnetic levitation systems using forces of attraction can generate guidance force automatically, but the damping force against lateral motion is negligible. However, the lateral damping characteristic was improved by using divided iron type magnets and rails. Using this turnout without movable parts will facilitate smooth direction switching.

• International Journal of Air-Conditioning and Refrigeration
• /
• 제16권4호
• /
• pp.109-116
• /
• 2008

Ground temperature restoration characteristics are the crucial factors to evaluate whether a ground source heat pump system can keep long time steady operation. They are mainly dependent on soil thermal properties, layout of pile group, operation/shutoff ratio, cooling/heating load, thermal imbalance ratio and so on. On the one hand, several types of vertical pile foundation heat exchangers are intercompared to determine the most efficient one by performance test and numerical method. On the other hand, according to the layout of pile group of a practical engineering and running conditions of a GSHP system in Shanghai, the temperature distribution during a period of five years is numerically studied. The numerical results are analyzed and are used to provide some guidance for the design of large-scale GSHP system.