• Journal of Korean Society of Steel Construction
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• v.20 no.4
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• pp.469-481
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• 2008

The inelastic design of the three-span continuous composite plate girder with consideration of moment redistribution over the interior pier is performed using the LRFD method. The design of the girder section, based on the inelastic method, is compared with that by the conventional elastic design. The length of the center span for the three-span continuous bridge ranges from 40m to 70m and the relative ratio of the span length is assumed to be 4:5:4. Although the AASHTO- LRFD specifications are applied in the design of the composite girder, the recently proposed new design live load is used. After determining the maximum positive and negative sections by the elastic design for various limit states, the amount of moment redistributed to the maximum positive moment section is calculated. With the increased design moment due to moment redistribution from the interior pier, the maximum positive section designed by the elastic method is checked for the strength limit state and the service limit state. The maximum negative moment section is redesigned by reducing the size of the steel girder relative to the section designed by the elastic method and the new section is checked for the service limit state. Based on the design results for the five bridges considered in this study, it is estimated that about 23% of steel can be saved in the interior pier section if it is designed by the inelastic method compared with that designed by the elastic method.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.2
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• pp.110-115
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• 2006

In pure P2P environment, it is possible to provide service by using a little real-time information without using accumulated information. But in case of using only a little information that was locally collected, quality of recommendation service can be fallen-off. Therefore, it is necessary to study a method to improve qualify of recommendation service by using users' context information. But because a great volume of users' context information can be recognized in a moment, there can be a scalability problem and there are limitations in supporting differentiated services according to fields and items. In this paper, we solved the scalability problem by clustering context information per each service field and classifying it per each user, using SOM. In addition, we could recommend proper services for users by quantifying the context information of the users belonging to the similar classification to the service requester among classified data and then using collaborative filtering.

• Journal of Korean Society for Quality Management
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• v.50 no.3
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• pp.407-424
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• 2022

Purpose: This study examines the relationship between the environment, society, and governance (ESG) perception of service providers and service quality by considering job satisfaction as a mediator in the Korean parcel delivery context. Methods: This study uses a multi-level analysis by incorporating organizational and individual levels of analysis. It employs a survey method for measuring the ESG perception of parcel delivery persons and service quality ratings from the Korean government. A hierarch regression analysis with 241 responses was used to test hypotheses. Results: The results of this study provide evidence that the ESG perception, particularly its social dimension, of parcel delivery persons is positively associated with service quality. This study also finds the positive effect of the ESG perception on job satisfaction. However, the mediating effect of job satisfaction between the ESG perception and service quality was not confirmed. Conclusion: This study presents significant implications for scholars and practitioners. Parcel delivery companies should implement relevant ESG activities and communicate them with their service persons to improve delivery service quality. The ESG perception of employees plays a critical role in the moment of truth in parcel service delivery to enhance customer satisfaction and service quality.

• Journal of the Chungcheong Mathematical Society
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• v.25 no.4
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• pp.747-752
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• 2012

When the service time distribution has a finite exponential moment, we present a large deviations result for the busy period distribution in the M/G/1 queue without the assumption of Abate and Whitt (1997) and Kyprianou (1971).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4A
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• pp.383-389
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• 2010

The concrete structural design provisions in Korea are based on ultimate strength design. Up to service load stage, it is assumed a linear stress-strain relation, but there is no stress-strain relationship for a concrete material from service load stage to limat state. According to the current provisions, an independent method is provided for the each calculation of deflection and crack width. In EC2 provisions based on limit state design, however, a stress-strain relationship of concrete is provided. Thereby, it is able to calculate a strength as well as a deflection directly from concrete stress-strain relationship. In this paper the moment-curvature relationship is directly calculated from a material law using equilibrium and compatibility conditions. Then strength and deflection are formulated. These results are compared with the values from the current provisions in Korea. From the results, the deflection based on a moment-curvature relationship is well agreed with experimental results and it is appeared that the deflection after the yielding of steel is also possible.

• Structural Engineering and Mechanics
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• v.91 no.3
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• pp.315-324
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• 2024

An expansive soil in 4970 special railway line in Dangyang City, China, has encountered a series of landslides due to the expansion characteristics of expansive soil over the past 50 years. Thereafter, a sheet-pile retaining structure was adopted to fortify the expansive soil slope after a comprehensive discussion. In order to evaluate the efficacy of engineering measure of sheet-pile retaining structure, the field test was carried out to investigate the lateral pressure and pile bending moment subjected to construction and service conditions, and the local daily rainfall was also recorded. It took more than 500 days to carry out the field investigation, and the general change laws of lateral pressure and pile bending moment versus local daily rainfall were obtained. The results show that the effect of rainfall on the moisture content of backfill behind the wall decreases with depth. The performance of sheet-pile retaining structure is sensitive to the intensity of rainfall. The arching effect is reduced significantly by employing a series of sheet behind piles. The lateral pressure behind the sheet exhibits a single-peak distribution. The turning point of the horizontal swelling pressure distribution is correlated with the self-weight pressure distribution of soil and the variation of soil moisture content. The measured pile bending moment is approximately 44% of the ultimate pile capacity, which indicates that the sheet-pile retaining structure is in a stable service condition with enough safety reserve.

• Proceedings of the Korean Society for Quality Management Conference
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• 2007.04a
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• pp.76-82
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• 2007

Upon the basis at the end of March 2005, we have the 38.91 million cellular phone subscribers over the country and the total diffusion rate of the cellular phone is reached up to 76.1%. At this moment, it can be said the most people use it since the demand is still going on. Turning to the operation company, this is serviced by the SK Telecom, LG Telecom, and KTF, and there are at least 7 manufactures producing it including Samsung, LG, KTF ever, Motorola, SKY, Pantac and Curitel, Most users periodically change the service vendor to the others for buying new model or changing the service vendor. It is understood the customer's action occurred by the differences of the brand cognition. In this study, along with some parameters including the difference of the vendor's brand cognition, difference of satisfaction (mobile telecommunication, product), and the possibility to buy the product again, I am going to find out the relationship between the satisfaction of the provider's service

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.295-300
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• 2004

We consider a G/M/1 queue with two-stage service policy. The server starts to serve with rate of ${\mu}1$ customers per unit time until the number of customers in the system reaches A. At this moment, the service rate is changed to that of ${\mu}2$ customers per unit time and this rate continues until the system is empty. We obtain the stationary distribution of the number of customers in the system.

• Journal of the Korean Society of Safety
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• v.24 no.5
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• pp.48-56
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• 2009

This paper presents the procedure for the optimal design of a PSC-I girder bridge considering life cycle cost (LCC). The load carrying capacity curves for the concrete deck, PSC-I girder and $\pi$-type pier were derived and used for the estimate of service lives. Total life cycle cost for the service life was calculated as sum of initial cost, damage cost, maintenance cost, repair and rehabilitation cost, user cost, and disposal cost. The advanced First Order Second Moment method was used to estimate the damage cost. The optimization method was applied to the design of PSC-I girder bridge. The objective function was set to the annual cost, which is defined by dividing the total life cycle cost by the service life, and constraints were formulated on the basis of Korean Standards. The optimal design was performed for various service lives and the effects of design factors were investigated.

• Proceedings of the Safety Management and Science Conference
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• 2008.04a
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• pp.401-415
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• 2008

Upon the basis at the end of March 2005, we have the 38.91 million cellular phone subscribers over the country and the total diffusion rate of the cellular phone is reached up to 76.1%. At this moment, it can be said the most people use it since the demand is still going on. Turning to the operation company, this is serviced by the SK Telecom, LG Telecom, and KTF, and there are at least 6 manufactures producing it including Samsung, LG, KTF ever, Motorola an d SKY. Most users periodically change the service vendor to the others for buying new model or changing the service vendor. It is understood the customer's action occurred by the differences of the brand cognition. In this study, along with some parameters including the difference of the vendor's difference of satisfaction (mobile telecommunication, product), and the possibility to buy the product again, I am going to find out the relationship between the satisfaction of the provider's service.