• Earthquakes and Structures
• /
• v.7 no.1
• /
• pp.101-117
• /
• 2014

This paper presents a reliability-based analysis on seismic performance of timber-steel hybrid shear wall systems. Such system is composed of steel moment resisting frame and infill wood frame shear wall. The performance criteria of the hybrid system with respect to different seismic hazard levels were determined through a damage assessment process, and the effectiveness of the infill wood shear walls on improving the seismic performance of the hybrid systems was evaluated. Performance curves were obtained by considering different target non-exceedance probabilities, and design charts were further established as a function of seismic weight. Wall drift responses and shear forces in wood-steel bolted connections were used as performance criteria in establishing the performance curves to illustrate the proposed design procedure. It was found that the presence of the infill wood shear walls significantly reduced the non-performance probabilities of the hybrid wall systems. This study provides performance-based seismic evaluations on the timber-steel hybrid shear walls in support of future applications of such hybrid systems in multi-story buildings.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.4
• /
• pp.509-515
• /
• 2011

When a manufacturing system is designed, various kinds of evaluation methods are used for selecting the best alternative. Net present value, inner rate of return and payback period are popular quantitative measures for the economic assessment, but other qualitative measures should be considered for evaluation. The analytic hierarchy process(AHP) has been used as the popular method for the multi criteria decision making problem that considers both quantitative and qualitative criteria. This paper explains the process of economic assessment, and how to use the AHP for evaluating the designs of the assembly lines for lens module installed in mobile phone.

• Journal of the military operations research society of Korea
• /
• v.24 no.1
• /
• pp.98-109
• /
• 1998

This study develops a maintenance strategy for a reparable 2-unit standby system. The maintenance strategy implies the waiting time to call the repair facility when the unit-1 fails. Almeida and Souza set up the multi-attribute utility function consisting of system availability and repair cost for several maintenance strategies and decide the optimal maintenance strategy that maximize the expected value of the utility function. We decide the optimal maintenance strategy satisfying the following two criteria about the utility function : maximum variance using Almeida and Souza's utility function. It both criteria are not satisfied at the same time for every strategies, the strategy maximizing the lower confidence limit for expected utility function is regarded as an optimal one.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.23 no.3
• /
• pp.63-73
• /
• 1998

The paper deals with interactive multiple criteria decision making procedure when decision maker (DM) specifies her or his preference in incomplete ways. Usually DM is willing or able to provide only incomplete information, because of time pressure and lack of knowledge or data. Under incomplete information on utility and attribute weight, the pairwise dominance checks result in strict or weak dominance values. Considering only strict dominance values sometimes fails to Prioritize alternatives because of fuzziness of preference information. Further there exists some information loss useful if used, otherwise. In this paper, we consider the outranking concept which implies the willingness of DM's taking some risk under the least favorable situation because she has enough reasons to admit the results. By comparing the magnitude of net preference degree of alternatives which is defined by difference between outrankings and outranked degree of each alternative, we can prioritize alternatives.

• Tunnel and Underground Space
• /
• v.5 no.2
• /
• pp.123-133
• /
• 1995

A two dimensional visco-plastic finite element model capable of handling the multistep excavaton was developed for investigating the effect of excavation-support sequences on the behaviour of underground openings in the jointed rock mass. Ubiquitous joint pattern was considered in the model and joint properties in each set were assumed to be identical. Passive, fully-grouted rockbolts were considered in the model. Visco-plastic deformations of joints and rockbolts were assumed to be governed by Mohr-Coulomb and von Mises yield criteria, respectively. With the ability of removing elements, the model can von Mises yield criteria, respectively. With the ability of removing elements, the model can simulate the multi-step excavation-support sequences. The reliability of the model to the stability analysis for the underground excavation in practice was checked by simulating the behavior of underground crude oil storage caverns under construction.

• Transactions of Materials Processing
• /
• v.6 no.4
• /
• pp.291-299
• /
• 1997

This paper is concerned with the design of process sequence to form the inner skin of landing gear. The inner skin of landing gear is a part of airplane which is known to be difficult to form its shape. Our study investigates the production method of inner skin and examines the design criteria by three dimensional elastic-plastic finite element method. Based on the results of simulation, design strategy for improving the process sequence is developed using stretch forming process. The final product of inner skin is produced in multi-stage operations with annealing treatment to meet the required capacity of press. The numerical results show that the newly designed process can produce the required part successfully within the design criteria.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2004.11a
• /
• pp.423-428
• /
• 2004

Flooding is one of the main causes of loss of lives and properties among various natural disasters in Korea. Flood risk maps are currently being produced in Korea but the progress is slow considering the necessity to map at nationwide scale. In this study, GIS-based multi-criteria decision making process which is normally used for resource management and site analysis was applied to locate flood vulnerable areas. Past records of flooding maps were analysed to extract topographic characteristics of flooded areas. The extracted characteristics were then set as criteria for flooding analysis using the Fuzzy and Analytic Hierarchy Process(AHP) methodology. Results from this study showed that an improved phased action plan was possible, because the flood vulnerable areas are shown in varying degrees of uncertainty unlike the conventional Boolean type GIS layer superimposition analysis.

• Journal of Home Health Care Nursing
• /
• v.20 no.2
• /
• pp.141-151
• /
• 2013

Purpose: The purpose of this study was to examine the economic effectiveness of by conducting a literature review of published articles, masters theses, and doctoral dissertations. Method: Prior to the literature review, inclusion-exclusion criteria were established. We then reviewed 1,029 CINAHL, MEDLINE, and Cochrane DB papers, and 153 RISS papers collected between Results: A total of 12 studies met the inclusion-exclusion criteria.-effectiveness: 6 cost-effectiveness studies, 1 cost-utility studies, and 5 cost-benefit studies. Each of the 12 reviewed studies concluded that home care nursing had greater economic benefits than other compared healthcare services. Conclusion: Home care nursing has significant economic benefits in multi health care service settings and for various patient groups. Therefore these results will be used a critical evidence for the development of economically effective home based health care systems for future policy making.

• Transactions of Materials Processing
• /
• v.13 no.8
• /
• pp.671-677
• /
• 2004

For the large reduction in tube cross section, the tube drawing process is usually performed by two successive passes, so called first drawing and second drawing. In multi-pass drawing process, the reduction balance is important to prevent drawing cracks. Therefore in this study, the model for uniform reduction distribution in two-pass drawing process has been developed on the basis of cross sectional variation of drawn tube. For the given product geometry the model provides optimal diameter and thickness that can evenly distribute drawing reductions. The capability of model is well confirmed by finite element analysis of tube drawing process. Criteria curves at various limit strains to determine whether the drawn tube would fail during drawing process are also proposed by using newly developed model.

• Proceedings of the Korea Technology Innovation Society Conference
• /
• 2001.05a
• /
• pp.369-385
• /
• 2001

A R&D project evaluation method has been applied for the national nuclear R&D projects in a developing-country setting. In the methodology, Saaty's analytic hierarchy process model is used to evaluate and rank of the selected nuclear R&D project which have a wide range of objectives and characteristics. The criteria used for evaluation related specifically to the Korea's evaluation needs and culture, and they are weighted according to their relative importance as perceived by the evaluator of the R&D project. As a real-world case of evaluation, we elicited and reproduced the evaluation process of the nuclear R&D projects which is going under the research process. As the results of the paper suggests, the methodology can be applied to the evaluation of the R&D projects and has much potential.