• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.5
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• pp.160-170
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• 2007

This study predicts Life Cycle Cost of RC Slab bridge case in maintenance and operation level and calculated economic efficiency by the avoidable costs of a bridge. This result of the study can be summarized as follow: (1) LCC analysis model on the bridge case is suggested. (2) Maintenance and operation level of a bridge have been divided, and LCC of the bridge case has been predicted at current maintenance and operation level and required maintenance and operation level. (3) Reduction costs is predicted by LCC of the bridge case, and its economic efficiency is calculated.

• Journal of Drive and Control
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• v.16 no.2
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• pp.43-50
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• 2019

The objective of this study was to reverse engineer a swash plate type piston pump mounted on a wheeled armored vehicle and to analyze the structure of the pump case. From the analysis, the weak parts were identified and corrected in the final design. Each element corresponding to the piston pump case was analyzed. The analytical method was given static boundary conditions, load conditions and confirmed displacement, strain, stress, and safety factor. Plastic deformation and damage were also confirmed and the component elements redesigned through structural analysis Structural analysis and vibration analysis were carried out for the components of the piston pump case. The piston pump model was finally modified by structural analysis and vibration analysis results for each component assembly, and a prototype was designed. Durability test and environmental test were carried out and the test results satisfied all of the requirements. Therefore, the analytical method presented in this study can be utilized as a methodology for element component design in the development of various piston pumps.

• Journal of the Korean Geosynthetics Society
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• v.21 no.2
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• pp.39-48
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• 2022

Unlike the horizontal strut, the corner strut causes bending behavior by the installation angle when soil pressure occurs, so there is a limit to its application as a elasto plastic method that requires only the axial stiffness of struts. Therefore, this study attempted to approach a method of modifying axial stiffness data to present an analysis method for corner struts in elasto plastic method, and linear elasticity analysis was used for this. And, through Linear elasticity analysis, axial stiffness data for corner struts installed at the actual site were calculated. The behavior of the retainingwall was confirmed by applying the calculated axial stiffness data of corner struts to elasto plastic method, and its applicability was evaluated by comparing it with the measurement results and the finite element analysis results. As a result of the study, when the axial stiffness data of the corner struts was applied using Linear elasticity analysis(Case 1, Case 3), the axial stiffness data decreased to 9% to 17% compared to the general method of applying the axial stiffness of the struts(Case 2, Case 4), and the displacement of the retainingwall increased to 25.33% to 64.42%. Comparing this result with the measurement results, when Linear elasticity analysis was used(Case 1, Case 3), the behavior of the retainingwall during the elasto plastic method was better shown.

• Journal of Korea Technology Innovation Society
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• v.14 no.4
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• pp.833-859
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• 2011

This study aims to draw the characteristics of the regional operation system of the shared research instrument service, which contributes to the R&D investment efficiency by the avoidance of duplicated research instrument investment and the enhancement of the network collaboration. So from the perspective of technology infrastructure policy and regional innovation system, Gyeonggi region of Korean metropolitan area has been analyzed for the case study. The case study has been conducted by 2 step process of within-case analysis and cross-case analysis. Firstly, the characteristics of operation system of the shared research instrument have been examined through various research methods. Secondly, in the cross-case analysis, the examined issues and problems have been organized by the matrix of 3 organizational governance characteristics and 4 issues to facilitate the regional policy approach. The issues deducted by the cross-case analysis have been deducted as (1) 'usage fee charge system', 'relevant method for the performance index and measurement of the instrument service management' for the regional policy led case, (2) 'performance management issue', 'financial and managerial accounting system for the instrument operating division', and 'change of budget support scheme' for the joint operation case and lastly (3) 'usage facilitation after the expiration of research lab support project' for the university led case.

• Progress in Medical Physics
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• v.26 no.3
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• pp.119-126
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• 2015

The purpose of this study is to analyze motion-induced dose error generated by each tumor motion parameters of irregular tumor motion in helical tomotherapy. To understand the effect of the irregular tumor motion, a simple analytical model was simulated. Moving cases that has tumor motion were divided into a slightly irregular tumor motion case, a large irregular tumor motion case and a patient case. The slightly irregular tumor motion case was simulated with a variability of 10% in the tumor motion parameters of amplitude (amplitude case), period (period case), and baseline (baseline case), while the large irregular tumor motion case was simulated with a variability of 40%. In the phase case, the initial phase of the tumor motion was divided into end inhale, mid exhale, end exhale, and mid inhale; the simulated dose profiles for each case were compared. The patient case was also investigated to verify the motion-induced dose error in 'clinical-like' conditions. According to the simulation process, the dose profile was calculated. The moving case was compared with the static case that has no tumor motion. In the amplitude, period, baseline cases, the results show that the motion-induced dose error in the large irregular tumor motion case was larger than that in the slightly irregular tumor motion case or regular tumor motion case. Because the offset effect was inversely proportion to irregularity of tumor motion, offset effect was smaller in the large irregular tumor motion case than the slightly irregular tumor motion case or regular tumor motion case. In the phase case, the larger dose discrepancy was observed in the irregular tumor motion case than regular tumor motion case. A larger motion-induced dose error was also observed in the patient case than in the regular tumor motion case. This study analyzed motion-induced dose error as a function of each tumor motion parameters of irregular tumor motion during helical tomotherapy. The analysis showed that variability control of irregular tumor motion is important. We believe that the variability of irregular tumor motion can be reduced by using abdominal compression and respiratory training.

• Convergence Security Journal
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• v.13 no.2
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• pp.101-109
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• 2013

Problem Based Learning(PBL) is one of effective teaching-learning strategy for enhancing military students' motivation, comparing with the other study method. After monitoring military student classes, we conclude that PBL can enhance the effectiveness of learning in War history case study education and finds merits; PBL assists students to play a more active role in the class, induces students to solve problems independently, and makes the learning military situation real case study. The case study is common in social sciences and life sciences. Case studies may be descriptive or explanatory. It is good for War history education. The demerit of PBL is a costly method as students should spend more time and institutions should provide more manpower and materials. This study suggests that more empirical researches on alternative teaching methods, including PBL, to a lecture in War history education.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.1
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• pp.93-109
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• 2022

Today, digital transformation in providing service value to companies that combine service and technology is becoming a necessity. In the transition period of digital transformation, various factors such as data, artificial intelligence technology, and partnerships can become competitive factors. In particular, digital transformation, which combines information and services with customers, creates a new business model that changes the entire industry and is presented as core competitiveness that creates customer value. From these aspects, the purpose of this case study is to derive competitive advantages on digital transformation using the case of company S. First, the study analyzes the same type of industry based on the case of app service. Second, this study presents preference factors in the operational process to enhance competitiveness by expanding user participation in accommodation reservation services. In addition, the customer service value model provides through the analysis of the five competitive factors in the operational process. This study elaborates the implications of the customer service value creation model in terms of new opportunities and challenges in digital transformation as a new customer service strategy.

• KIEAE Journal
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• v.15 no.1
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• pp.77-82
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• 2015

The purpose of this study is to compare the thermal insulation performance of windows according to the formation of air layer and to evaluate its energy efficiency on a selected standard house. A thermal insulation test, KS F 2278 was used to measure U-values (Heat transmission coefficients) for the following three cases: the first case (Case 1) is a Low-E pair glass (Argon injected), the second case (Case 2) is a Low-E pair glass with the air cap attached on the glass surface, and the third case (Case 3) is a Low-E pair glass, on the frame of which the air cap is attached. The evaluation of the energy efficiency was conducted according to a building energy calculation method from ISO 13790, calculation of energy use for space heating and cooling, using the U-values obtained from the thermal insulation tests. As results of the tests, the U-values of Case 1, Case 2, and Case 3 were $1.668W/m^2{\cdot}K$, $1.568W/m^2{\cdot}K$, and $1.319W/m^2{\cdot}K$ respectively. The Case 2 had about 5.9% lower value than the Case 1, and the Case 3 had about 20.9% lower value than the Case 1. It seems that the thermal performance of the windows is attributed to an increase of the heat resistance and the thickness of air layer. An evaluation of the energy efficiency of the three cases on the selected standard house showed that the amount of heating energy demand per unit area was $7.776kWh/m^2{\cdot}yr$ for the Case $1,6.856kWh/m^2{\cdot}yr$ for the Case 2, and $4.856kWh/m^2{\cdot}yr$ for the Case 3. This study suggests that the formation of air layer (by using air cap) and its thickness should reduce the heat energy demand and thus improve the energy saving efficiency

• Korean Institute of Interior Design Journal
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• v.24 no.6
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• pp.68-78
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• 2015

The servicescape of a design hotel means the physical environment in which a service is produced and consumed. Servicescape refers to the comprehensive physical environment perceived by users and is composed of physical elements such as ambient conditions, space, function, signs, symbols and artifacts. For a successful operation of a design hotel, it is necessary to investigate the design hotel's servicescape types according to characteristics of design hotel's servicescape to provide various servicescape. The purpose of this study is to classify the types of servicescape on design hotel and analyze characteristics through the case study. A case study on Europe's design hotels to find various servicescape design methods was conducted. According to characteristics of design hotel the types, it is also categorized into four different types: history/tradition, art/culture, collaboration, locality. The case study demonstrated that European design hotels were making many efforts for their uniqueness and differentiation by considering the cultural and historical characteristics of their city and providing art and cultural space for their community. Design hotels in Korea should not only provide visitors with opportunities to have special experience through the nation's own culture and history but also serve as a place of community activities.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.3
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• pp.34-41
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• 2010

'Aviation Safety' is the state in which the risk of harm to persons or of property damage is reduced to, and maintained at or below, an acceptable level through a continuing process of hazard identification and risk management in the aviation field. 'Risk' is the assessed potential for adverse consequences resulting from a hazard and 'Risk assessment' involves consideration of both the frequency and the severity of any adverse consequence. This study focused on the risk frequency about a case airport which does not meet the 'Runway end safety area' requirement of ICAO SARPs and Korea standards and used 'RSA risk model' for estimating the risk frequency. As results of this study, risk frequency of the runway end safety areas in the case airport is higher than that of 'Runway end safety area' requirement of ICAO SARPs and Korea standards, which means that alternatives for risk frequency mitigation to a level as low as reasonably practicable is required in the case airport. The optimum solution analysed from this study is to impose restriction of aircraft operation when the runway condition is poor(icing condition) and also it snows in the case airport.