• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.3
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• pp.181-196
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• 2014

Cloud computer technology currently provides diverse services based on a comprehensive environment ranging from hardware to solution, network and service. While the target of services has been extended from institutions and corporations to personal infrastructure and issues were made about security problems involved with protection of private information, measures on additional security demands for such service characteristics are insufficient. This paper proposes a multi-session authentication technique based on the characteristics of SaaS (Software as a Service) among cloud services. With no reliable authentication authority, the proposed technique reinforced communication sessions by performing key agreement protocol safe against key exposure and multi-channel session authentication, providing high efficiency of performance through key renewal using optimzied key table. Each formed sessions have resistance against deprivation of individual confirmation and service authority. Suggested confirmation technique that uses these features is expected to provide safe computing service in clouding environment.

• Journal of Korean Society for Quality Management
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• v.40 no.3
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• pp.381-393
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• 2012

Purpose: Considering various measurements for healthcare service quality, the purpose of this study is to examine measurement items for healthcare service quality (HCSQ) based on previous study and service quality evaluation institutions in the international community. Methods: The proposed research model was tested using measurement analysis, based on data collected from 387 respondents in the selected hospital with more than 500 beds in South Korea. Results: The results of the study shed insights about the relative importance of quality items as degree of improvements of care services tangible, safety, efficiency, and empathy. Also, the study provides new measurement model for healthcare service quality. Conclusion: Healthcare organization thrives to find the key factors for improving quality of care and service that meet customers' needs and expectations.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.42-53
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• 2006

The delivery of high service quality is an evitable strategy that has been related to a success in discount store industry. Greater competitiveness has caused discount store firms to be increasingly aware of the importance of service quality to be on a competitive edge. Also, the fact that service quality leads to customer satisfaction has driven many researchers and practitioners to focus on the issue. What we suggest is that customer's expectation change of service quality cannot be regarded as two totally unrelated processes. If quality judgments are based on expectations, it is important to understand the origins of those expectation change. Therefore, if being of effecting factors between the latest expectation and the changed expectation of service quality will prove out, service firms are possible to operate efficiency quality management for getting customer satisfaction.

• Journal of Information Processing Systems
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• v.18 no.6
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• pp.741-754
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• 2022

Openstack is widely used as a representative open-source infrastructure of the service (IaaS) platform. The Openstack Identity Service is a centralized approach component based on the token including the Memcached for cache, which is the in-memory key-value store. Token validation requests are concentrated on the centralized server as the number of differently encrypted tokens increases. This paper proposes the practical Byzantine fault tolerance (PBFT) blockchain-based Openstack Identity Service, which can improve the performance efficiency and reduce security vulnerabilities through a PBFT blockchain framework-based decentralized approach. The experiment conducted by using the Apache JMeter demonstrated that latency was improved by more than 33.99% and 72.57% in the PBFT blockchain-based Openstack Identity Service, compared to the Openstack Identity Service, for 500 and 1,000 differently encrypted tokens, respectively.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.4
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• pp.483-491
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• 2012

It is expected that, in the future, DC power service will be widely used for photovoltaic home power generation systems, since DC consuming devices are ever increasing. Instead of using multiple converters to convert DC to AC and then AC to DC, the power service could solely be based on DC. This would eliminate the need for converters, reducing the cost, complexity, and possibly increasing the efficiency. However, configuration of direct DC power service with mechanical contacts can cause spark voltage or an electric shock when the switch is turned on and off. To solve these problems, in this paper, a contactless power supply for a DC power service that can transfer electric power produced by photovoltaics to the home electric system using magnetic coupling instead of mechanical contacts has been proposed. The proposed system consists of a ZVS boost converter, a half-bridge LLC resonant converter, and a contactless transformer. This proposed contactless system eliminates the use of DC switches. To reduce the stress and loss of the boost converter switching devices, a lossless snubber with coupled inductor is applied. In this paper, a switching frequency control technique using the contactless voltage sensing circuit is also proposed and implemented for the output voltage control instead of using additional power regulators. Finally, a prototype consisted of 150W boost converter has been designed and built to demonstrate the feasibility of the proposed contactless photovoltaic DC power service. Experimental results show that 74~83% overall system efficiency is obtained for the 10W~80W load.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.60-66
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• 2016

Compound logistics is a service aimed to enhance logistics efficiency by supporting that shippers and consigners jointly use logistics facilities. Many of these services have taken place both domestically and internationally, but the joint logistics services for e-commerce have not been spread yet, since the number of the parcels that the consigners transact business is usually small. As one of meaningful ways to improve utilization of compound logistics, we propose a brokerage service for shipper and consigners based on the hybrid recommendation system using very well-known classification and clustering methods. The existing recommendation system has drawn a relatively low satisfaction as it brought about one-to-one matches between consignors and logistics vendors in that such matching constrains choice range of the users to one-to-one matching each other. However, the implemented hybrid recommendation system based brokerage agent service system can provide multiple choice options to mutual users with descending ranks, which is a result of the recommendation considering transaction preferences of the users. In addition, we applied feature selection methods in order to avoid inducing a meaningless large size recommendation model and reduce a simple model. Finally, we implemented the hybrid recommendation system based brokerage agent service system that shippers and consigners can join, which is the system having capability previously described functions such as feature selection and recommendation. As a result, it turns out that the proposed hybrid recommendation based brokerage service system showed the enhanced efficiency with respect to logistics management, compared to the existing one by reporting two round simulation results.

• Journal of Convergence for Information Technology
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• v.8 no.5
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• pp.243-249
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• 2018

This study is to verify the accommodation attitudes and intention of use of the end-users to use the drone distribution delivery service that is to be introduced in Korea. For a research purpose, the research model and hypothesis in this study have been set based on by using the SPSS 22.0. Upon these, the extended technology acceptance model has been used to verify the correlation service of new technology, and the result has shown that the user of drone distribution delivery service has a causal relationship with individual innovation and that the accommodation behavior and intention of use have a causal relationship with economic efficiency and convenience. However, there was no causal relation from a perceived risk. Hence, based on the results of study about accommodation behaviors and intention of use of the end users of drone distribution delivery service, the marketing implications have been provided for commercialization of drone delivery service.

• Quality Improvement in Health Care
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• v.22 no.1
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• pp.11-26
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• 2016

The Organization for Economic Cooperation and Development, which has continuously evaluated the performance of healthcare systems, has recently invested much effort into hospital performance measurement. The purpose of this paper is to introduce the hospital performance measurement programs operated by international organizations or at the national level based on the OECD's hospital performance project. Health Insurance Review & Assessment service (HIRA)'s quality assessment was analyzed based on the analytical framework of the OECD's hospital performance project. The hospital performance measurement programs of WHO, Canada, Australia, United States and United Kingdom are briefly explored, in view of the conceptual framework, key performance dimensions and indicators that are currently in use. The OECD suggested seven key dimensions of hospital performance: timeliness, efficiency, continuity, effectiveness and appropriateness, staff orientation, patient orientation and safety. The analysis of the quality assessment program of HIRA, which operates 36 diseases and procedures and 347 indicators, shows that the numbers of indicators are relatively small in the areas of safety, patient centeredness and efficiency. Continuity of care and staff orientation are not fully developed also, but the situations are similar in other countries. In conclusion, hospital performance measurement using stable and comprehensive data should be developed to improve overall system performance, and discussions on a conceptual framework that can lay out directions and key performance domains need to take into place.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1721-1723
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• 2002

In 3rd-generation mobile communication systems providing packet service, optimal scheduling algorithms we needed to increase service efficiency. In this paper, three scheduling algorithms (SP, EDF, and RPQ) which have been studied in the field of computer networks are applied with transmit power constraint to an interference-limited CDMA system, proving to be efficient.

• Spatial Information Research
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• v.18 no.4
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• pp.75-88
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• 2010

Recent development in wireless communication and mobile positioning technologies make geosensor networks widely used in the various fields of real world. As a result, much research has been done on the middleware that uses limited energy resources efficiently. However, because traditional middleware does not consider the characteristics of sensor node, such as computing power and specification, the existing middleware call not support the sensor nodes with only the restricted system resource. Therefore, in this paper, we design and implement a new Bytecode based Data Service Middleware supporting energy efficiency in geosensor networks. At first, the proposed middleware provides the optimized functions for sensor nodes by using minimum by tee ode instruction set and data manager supporting hardware abstraction. Secondly, the proposed middleware increases the energy efficiency of sensor node through both data aggregation query processing and data filtering that minimize data transmission by eliminating unnecessary data. Finally, we show from our performance analysis that the proposed middleware is more energy efficient than the existing SwissQM.