• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.1
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• pp.145-164
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• 2023

Cloud computing offers a platform that is both adaptable and scalable, making it ideal for outsourcing data for sharing. Various organizations outsource their data on cloud storage servers for availing management and sharing services. When the organizations outsource the data, they lose direct control on the data. This raises the privacy and security concerns. Cryptographic encryption methods can secure the data from the intruders as well as cloud service providers. Data owners may also specify access control policies such that only the users, who satisfy the policies, can access the data. Attribute based access control techniques are more suitable for the cloud environment as they cover large number of users coming from various domains. Multi-authority attribute-based encryption (MA-ABE) technique is one of the propitious attribute based access control technique, which allows data owner to enforce access policies on encrypted data. The main aim of this paper is to comprehensively survey various state-of-the-art MA-ABE schemes to explore different features such as attribute and key management techniques, access policy structure and its expressiveness, revocation of access rights, policy updating techniques, privacy preservation techniques, fast decryption and computation outsourcing, proxy re-encryption etc. Moreover, the paper presents feature-wise comparison of all the pertinent schemes in the field. Finally, some research challenges and directions are summarized that need to be addressed in near future.

• Health Policy and Management
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• v.10 no.2
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• pp.1-21
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• 2000

This study reviewde various parametic and nonparametic method for forexasting hospital closures in Korea. We compared multivariate discriminant analysis, multivartiate logistic regression, classfication and regression tree, and neural network method based on hit ratio of each model for forecasting hospital closure. Like other studies in the literture, neural metwork analysis showed highest average hit ratio. For policy and business purposes, we combined the four analytical method and constructed a foreasting model that can be easily used to predict the probabolity of hospital closure given financial information of a hospital.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2006.11a
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• pp.59-75
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• 2006

Independent innovation is the key factor to enhance competitiveness in China auto industry. This article is based on current status analysis of China auto industry independent innovation and it points out the problems and causes that exist in the independent innovation process. It also proposes policy and suggestions to accelerate cultivation of independent innovation in China auto industry.

• Health Policy and Management
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• v.6 no.1
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• pp.1-28
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• 1996

The paper analyzes OECD health systems from the perspective of historical institutionalism. Criticizing the dependence of Korea's national health program on Pacific countries such as Japan and the U.S., it suggests that European experiences of national health programs can be a model of the Korean health system in the future. Based on an inquiry into Italian and British cases of national health systems, the author emphasizes (1) the role of local governemts in national health programs, and (2) the integration of a national health program with public health programs.

• Health Policy and Management
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• v.25 no.2
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• pp.67-70
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• 2015

To establish an appropriate policy for robotic surgery in Korea, the National Evidence-based Collaborating Agency (NECA) and the Korean Society of Health Policy and Administration held a round-table conference (RTC) to gather opinions through a comprehensive discussion of scientific information in gastric cancer. The NECA RTC is a public discussion forum wherein experts from diverse fields and members of the lay public conduct in-depth discussions on a selected social issue in the health and medical field. For this study, representatives from the medical field, patient groups, industry, the press, and policy makers participated in a discussion focused on the medical and scientific evidence for the use of robotic surgery in gastric cancer. According to the RTC results, robotic surgery showed more favorable results in safety and efficacy than open surgery and it is similar to laparoscopy. When the cost-effectiveness of robotic surgery and laparoscopy is compared, robotic surgery costs are higher but there was no difference between the two of them in terms of effectiveness (pain, quality of life, complications, etc.). In order to resolve the high cost issue of the robotic surgery, a proper policy should be implemented to facilitate the development of a cost-effective model of the robotic surgery equipment. The higher cost of robotic surgery require more evidence of its safety and efficacy as well as the cost-effectiveness issues of this method. Discussions on the national insurance coverage of robotic surgery seems to be necessary in the near future.

• Journal of Intelligence and Information Systems
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• v.6 no.1
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• pp.73-82
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• 2000

This study examined the characteristicso f the knowledge discovery and data mining algorithms to demonstrate how they can be used to predict health outcomes and provide policy information for hypertension management using the Korea Medical Insurance Corporation database. Specifically this study validated the predictive power of data mining algorithms by comparing the performance of logistic regression and two decision tree algorithms CHAID (Chi-squared Automatic Interaction Detection) and C5.0 (a variant of C4.5) since logistic regression has assumed a major position in the healthcare field as a method for predicting or classifying health outcomes based on the specific characteristics of each individual case. This comparison was performed using the test set of 4,588 beneficiaries and the training set of 13,689 beneficiaries that were used to develop the models. On the contrary to the previous study CHAID algorithm performed better than logistic regression in predicting hypertension but C5.0 had the lowest predictive power. In addition CHAID algorithm and association rule also provided the segment characteristics for the risk factors that may be used in developing hypertension management programs. This showed that data mining approach can be a useful analytic tool for predicting and classifying health outcomes data.

• Journal of the Korean Operations Research and Management Science Society
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• v.16 no.1
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• pp.135-146
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• 1991

This paper shows the infinite horizon model of Partially Observable Markov Decision Process with lagged information. The lagged information is uncertain delayed observation of the process under control. Even though the optimal policy of the model exists, finding the optimal policy is very time consuming. Thus, the aim of this study is to find an .eplison.-optimal stationary policy minimizing the expected discounted total cost of the model. .EPSILON.- optimal policy is found by using a modified version of the well known policy iteration algorithm. The modification focuses to the value determination routine of the algorithm. Some properties of the approximation functions for the expected discounted cost of a stationary policy are presented. The expected discounted cost of a stationary policy is approximated based on these properties. A numerical example is also shown.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.3
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• pp.71-84
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• 2009

This paper considers a remanufacturing and purchasing planning problem, in which either used products(or wastes) are remanufactured or remanufactured products(or final products) are purchased to satisfy dynamic demands of remanufactured products over a discrete and finite time horizon. Also, as remanufactured products are purchased more than or equal to a special quantity Q, a discount price policy is applied. The problem assumes that the related cost(remanufacturing and inventory holding costs of used products, and the purchasing and inventory holding costs of remanufactured products) functions are concave and backlogging is not allowed. The objective of this paper is to determine the optimal remanufacturing and purchasing policy that minimizes the total cost to satisfy dynamic demands of remanufactured products. This paper characterizes the properties of the optimal policy and then, based on these properties, presents a dynamic programming algorithm to find the optimal policy. Also, a network-based procedure is proposed for the case of a large quantity of low cost used products. A numerical example is then presented to demonstrate the procedure of the proposed algorithm.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.652-654
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• 2001

본 논문에서는 네트워크 기반의 침입 탐지 및 대응을 위한 정책 기반 망 관리 (NS-PBNM : Network Security Policy Based Network Management)에 핵심 정책 정보 모델 (PCIM :Policy Core Information Model) 을 적용하는 시스템 구현 방안을 제시한다. 이 시스템은 여러 장치를 유연성 있게 통합적으로 관리판다는 정책 기반 망 관리의 목적뿐만 아니라, 정책을 표현, 관리, 공유 및 재사용 하는데 있어 호환성 및 확장성을 확보한다는 PCIM의 목적을 동시에 달성한다. 먼저 NS-PBNM의 구조를 제시하고 이 구조를 기반으로 PCIM을 적용하는 방안을 제시한다. PCIM은 네트워크 침입 탐지 및 대응이라는 기능을 수행하는데 있어 네트워크 보안 정책 정보 모델로 확장된 후, 정책 서버의 정책 관리 도구와 정책 저장소의 구조를 결정한다.

• Journal of Information Technology Applications and Management
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• v.22 no.4
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• pp.225-251
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• 2015

This paper analyzed factors for employees to violate information security policy in financial companies based on the theory of reasoned action (TRA), general deterrence theory (GDT), and information security awareness and moderating effects of perceived sensitivity of customer information. Using the 376 samples that were collected through both online and offline surveys, statistical tests were performed. We found that the perceived severity of sanction and information security policy support to information policy violation attitude and subjective norm but the perceived certainty of sanction and general information security awareness support to only subjective norm. Also, the moderating effects of perceived sensitivity of customer information against information policy violation attitude and subjective norm were supported. Academic implications of this study are expected to be the basis for future research on information security policy violations of financial companies; Employees' perceived sanctions and information security policy awareness have an impact on the subjective norm significantly. Practical implications are that it can provide a guide to establish information security management strategies for information security compliance; when implementing information security awareness training for employees to deter violations by emphasizing the sensitivity of customer information, a company should make their employees recognize that the customer information is very sensitive data.