• Journal of Industrial Technology
• /
• v.19
• /
• pp.245-251
• /
• 1999

The joint in the concrete pavement provides a control against transverse or longitudinal cracking at slab, which may be caused by temperature or moisture variation during or after hydration. Without control of cracking, random crack may cause more serious distresses and result in structural or functional failure of pavement system. Sometimes, joint itself, purposed to control crack, may cause a distresses in joint due to its inherent weakness in structural integrity. Thus, the load transfer capacity in joint is very important for serviceability and durability. The purpose of this dissertation was to develop an evaluation system at joints of jointed concrete pavement using finite element analysis was performed using ILLI-SLAB program with a selected variables which might affect fairly to on the performance of transverse joints. The most significant variables were selected from precise analysis. It was concluded that the variables which most significantly affect to pavement deflections are the modulus of subgrade reaction(K) and the modulus of dowel/concrete interaction(G), and limiting criteria on the performance of joints at JCP at 300pci, 500,000 lb/in. respectively.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2008.04a
• /
• pp.325-330
• /
• 2008

In this study 3- and 6-story flat plate structures designed only for gravity load are retrofitted with steel plates and braces and their seismic performances are evaluated to verify the effect of seismic retrofit. According to the analysis results obtained from nonlinear static analysis both the strength and stiffness are significantly enhanced as a result of the seismic retrofit. When buckling-restrained braces are used instead of conventional braces, the structures show more ductile behavior, especially in the 3-story structure.

• Journal of Applied Tourism Food and Beverage Management and Research
• /
• v.15 no.1
• /
• pp.1-17
• /
• 2004

This study analyzed the priority of decision-making attributes considered as the customers select the family restaurant with Analytic Hierarchy Process, which is the method for quantitative analysis. The result of analysis revealed that the food factor in the first stage of evaluation attributes was the most important and in the second stage, an atmosphere factor of place, an affiliated card factor of promotion, a taste factor of food and a kind attitude factor of employee were important respectively.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.34 no.3
• /
• pp.105-124
• /
• 2009

Data Envelopment Analysis (DEA) is a methodology of computing the relative efficiency of each decision making unit (DMU) by comparing it with other DMUs having similar input and output structure. In this paper, we compare the efficiency of Korean rail transit corporations using DEA. To do this, we design a DEA-AR/AHP model, and evaluate efficiency by comparing the subway operating agencies of six big cities. The analysis reveals that Seoul Metro and Seoul city railroad construction turn out to be the most efficient groups. The result of this research can provide helpful information for effective management in a domestic subway operating agency.

• Journal of Mechanical Science and Technology
• /
• v.16 no.2
• /
• pp.182-191
• /
• 2002

The reliable stress intensity factor analysis is required for fracture mechanics design or safety evaluation of mechanical joints at which cracks often initiate and grow. It has been reported that cracks in mechanical joints usually nucleate as corner cracks at the faying surface of joints and grow as elliptical arc through cracks. In this paper, three dimensional finite element analyses are performed for elliptical arc through cracks in mechanical joints. Thereafter stress intensity factors along elliptical crack front including two surface points are determined by the virtual crack closure technique. Virtual crack closure technique is a method to calculate stress intensity factor using the finite element analysis and can be applied to non-orthogonal mesh. As a result, the effects of clearance on the stress intensity factor are investigated and crack shape are then predicted.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.5 no.6
• /
• pp.141-147
• /
• 1997

For the effective finite element analysis of the structures including material interfaces or contact surfaces, interface elements are proposed. Most of early works in this problem require not only iterative computation but also complex formulation because of the kinematic nonlinearities caused from the discontinuous behavior and the stress concentration phenomena. The proposed elements, however, are consistently formulated using relative displacements and tractions between top and bottom regular finite elements. The effectiveness of these elements are shown by solving various numerical sample problems including an leaf spring and comparing with results of general finite element analysis. As a result, more stable solutions are conveniently obtaines using interface elements than regular finite elements.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2005.05a
• /
• pp.294-299
• /
• 2005

A machining center is a complex dynamic system whose behavior influences the machining stability and machined surface quality. This paper focused on establishment of a measurement system and experimental study on static, dynamic, and modal analysis of a machining center. The dynamic stiffness result by the analysis showed the weak part of the machining center. The results provided structure modification data for getting better dynamic behaviors.

• Journal of The Korean Society of Integrative Medicine
• /
• v.8 no.4
• /
• pp.277-289
• /
• 2020

Purpose : This study aims to confirm the clinical usefulness of computerized cognitive therapy program for patients with brain diseases in Korea and to present basic data that can confirm the effectiveness of computerized cognitive therapy program to experts related to rehabilitation in the future. Methods : A systematic review and meta-analysis research method was used to confirm the clinical effectiveness of computerized cognitive therapy applied to patients with brain diseases in Korea. Based on the national institute of health and medical colleges association (NECA) systematic literature manual and preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines for conducting research through systematic review and meta-analysis methods. Systematic review was PICOST-SD was used to research and select papers. For meta-analysis, the data was input and analyzed separately by literature result using the revman manager 5.3 program and the results were presented visually through tables and forest, funnel plot figure. Results : As a result of comprehensive analysis of the contents of the finally selected literature, it as found that studies on stroke and dementia were mainly conducted. In addition, through the evaluation of the quality of the literature, most of the existing computerized cognitive therapy studies were identified as high-quality studies, but the results were insufficient for randomization and blinding. And through meta-analysis, the clinical effectiveness of computerized cognitive therapy on cognitive function, activities of daily living, and visual perception function of patients with brain disease was found. Conclusion : The research literature that applied computerized cognitive therapy to brain disease subjects was comprehensively analyzed and identified. It is thought that this could be used as basic data on the characteristics of cognitive therapy that should be applied to patients with brain diseases in the future and the usefulness of computerized cognitive therapy program in actual clinical practice.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.10a
• /
• pp.409-429
• /
• 2006

In designing rock-socketed drilled shaft, bearing capacity evaluation is very important because the maximum values of base and side resistance are not generally mobilized at the same value of displacement, FHWA and AASHTO code suggest different ultimate bearing capacity formular according to rock type and shaft settlement. In domestic code suggest base resistance and side resistance can be added on condition that after confirming the result of field load test with axial load transfer test. This paper shows that static load test and hi-directional load test result analysis of deep rock-socketed drilled shaft in three different sites. Load-settlement curve, t-z, and q-w curve in rock-socketed part were calculated and compared. t-z curve in weathered and soft rock showed no deflection softening behavior in pretty large strain (about 2-3% of diameter). Ultimate resistance could be the summation of side resistance and base resistance in rock-socketed drilled shaft in domestic sites.

• Convergence Security Journal
• /
• v.23 no.2
• /
• pp.95-102
• /
• 2023

The purpose of this paper was to confirm the operational level of the military department of universities, which plays a key role in the officer training process, through empirical research and confirm meaningful results for improvement. There are 11 university military departments operated through the Army, agreements, and semi-agreement, and the Data Envelopment Analysis (DEA) was applied from the perspective of resource input and performance for each university's military department operation to analyze relative efficiency and confirm specific directions for improvement. As a result of operational efficiency analysis, 6 DMUs (Decsision Making Unit) were found to be efficient in the BCC model out of 11 DMUs, and the evaluation results could be confirmed through classification of efficient and inefficient groups through data capture analysis. This paper may be of practical value in that it checks the efficiency of the comparative university military departments and confirms specific information for development through the DEA-Additive model that reflects several evaluation factors at once. Through this, the operators of each university's military department are admitted.