• Journal of the Korean Society of Systems Engineering
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• v.8 no.2
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• pp.57-67
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• 2012

It is the sensitivity and confidentiality of nuclear power plant decommissioning cost that prevent detailed cost information to be released to the public, which causes some limitation to analyze and reuse the costs. This limitation to access cost information means that the lessons learned from preceding cost estimating may not systematically feed back into following cost estimates. As an alternative, decommissioning cost estimation framework is indispensable to reflecting available experience and knowledge for decommission costs. This study provides the cost estimation framework including data flow and structuralization based on engineering and bottom up approach to enhance decommissioning cost estimation.

• Asia pacific journal of information systems
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• v.16 no.2
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• pp.143-158
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• 2006

This paper considers probable determinants of the application software outsourcing costs and focuses on the service level agreement (SLA) influence. Recently, outsourcing clients and vendors have contracted SLA and tried to reflect them on outsourcing prices. While application software maintenance has been one of the most frequently outsourced functions, its cost did not reflect the service level requirements by the client. This paper empirically shows that the service urgency requirement on SLA increases the maintenance programmers' effort and thus increases the vendor's cost. This result can be used by vendors for program allocation purposes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.8
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• pp.1825-1842
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• 2013

Rapid growth of the IT industry has led to significant energy consumption in the last decade. Data centers swallow an enormous amount of electrical energy and have high operating costs and carbon dioxide excretions. In response to this, the dynamic consolidation of virtual machines (VMs) allows for efficient resource management and reduces power consumption through the live migration of VMs in the hosts. Moreover, each client typically has a service level agreement (SLA), this leads to stipulations in dealing with energy-performance trade-offs, as aggressive consolidation may lead to performance degradation beyond the negotiation. In this paper we propose a heuristic based resource allocation of VM selection and a VM allocation approach that aims to minimize the total energy consumption and operating costs while meeting the client-level SLA. Our experiment results demonstrate significant enhancements in cloud providers' profit and energy savings while improving the SLA at a certain level.

• Journal of the Korea Society of Computer and Information
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• v.20 no.7
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• pp.65-76
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• 2015

This study investigates predictors of continuance intention and purchase intention in mobile application(App) stores. This study identifies the structural relationships among app store quality, user habit, switching costs, user loyalty, continuance intention, and purchase intention in mobile application stores. The results indicate that user loyalty increases continuance intention and purchase intention and that user habit positively affects perceived switching costs and user loyalty. App store quality is a formative construct including quality of content, ease of use, and security. App store quality affects user habit positively. This study theoretically and practically contributes to the integration of influential factors for continuance intention as well as purchase intention.

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.343-350
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• 1998

This paper is aims at identifying the minimum farm size of the greenhouse vegetable cooperatives. Farm cooperative is one of the institutional measurments for the seeking of economy of scale which could not be found in family farm. In this paper 5 cooperatives and 5 farmhouseholds which have been managed vegetable greenhouse were surveyed. The results are as follows; First, cooperatives had 29.3% less on the fixed costs, and received 43% more on prices than general vegetable farmhouseholds. This means that the cooperatives have economy of scale. Second, to establish full organized coopratives, cooperative sizes must be more than 4,582 pyung, considering the government target which will be loaned 80% goverment loan of total facility costs with no subsidy.

• Management & Information Systems Review
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• v.25
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• pp.83-114
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• 2008

We examine whether spinoffs improve long-run stock returns and analyze the factors of long run stock returns. The measures of long run stock returns are CAR(Cumulative Abnormal Returns) and BHAR(Buy and Hold Abnormal Returns). The expected factors of abnormal returns are methods of spinoffs, size, BV/MV, administrative costs, cashflow and Herfindahl index. We find that long-run returns of the case such as carve-out methods, small size, high BV/MV, low administrative costs, low cashflow and low Herfindahl index are larger than those of other cases. We show positive relationship between spinoffs and long-run stock returns(CAR and BHAR). The results supports spinoffs, as the methods of focusing on core business, are very usefulness of corporate restructuring.

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.2
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• pp.81-87
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• 1999

This paper discusses a bicriterion approach to sequencing with time/cost trade-offs. The first problem is to minimize the total flow time and the maximum tardiness. And second is to the maximum tardiness and resource allocation costs. This approach, which produces an efficient flintier of possible schedules, has the advantage that it does not require the sequencing criteria to be measurable in the same units as the m allocation cost. The basic single machine model is used to treat a class of problems in which the sequencing objective is to minimize the maximum completion penalty. It is further assumed that resource allocation costs can be represented by linear time/cost function.

• Information and Communications Magazine
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• v.10 no.8
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• pp.77-87
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• 1993

There has been increasing attention paid to the influence of fascimile type of technologies on transportation costs. This attention is noticeable in large business companies, as fascimile become widely available in Korea. The importance of the fascimile usage is that it might effectively substitute for transportation, thereby reducing transportation costs. This paper presents an analysis of cost saving resulting from fascimile usage for substitutable trips. Data were collected from business companies on various aspects of the fascimile usage patterns, with particular emphasis on usage behavior substitutable for trips. Although by no means comprehensive, the analysis revealed that significant benefits can be derived from the usage of fascimile for substitutable trips in business settings. The results of benefit estimation show that net benefits turn out to be 7,608 won and 5,055 won per one usage for large and small companies respectively. If traffic congestion were to be considered, total social benefits would be higher.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.6079-6097
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• 2018

Safety-related systems (SRSs) has widely used in shipbuilding and power generation to prevent fatal accidents and to protect life and property. Thus, SRS performance is a high priority. The safety integrity level (SIL) is the relative performance level of an SRS with regard to its ability to operate reliably in a safe manner. In this article, we proposed an optimal design procedure to achieve the targeted SIL of SRSs. In addition, a more efficient failure mode and effects diagnostic analysis (FMEDA) process and optimization model were developed to improve cost efficiency. Based on previous IEC 61508 diagnostic analyses that revealed unnecessary costs associated with excessive reliability, the new approach consists of two phases: (i) SIL evaluation by FMEDA, and (ii) solution optimization for achieving the target SIL with minimal cost using integer-programming models. The proposed procedure meets the required safety level and minimizes system costs. A case study involving a gas-detection SRS was conducted to demonstrate the effectiveness of the new procedure.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.4
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• pp.1249-1265
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• 2022

Video streaming has become one of the most popular applications for mobile devices. The network bandwidth required for video streaming continues to exponentially increase as video quality increases and the user base grows. Multi-Path TCP (MPTCP), which allows devices to communicate simultaneously through multiple network interfaces, is one of the solutions for providing robust and reliable streaming of such high-definition video. However, mobile video streaming over MPTCP raises new concerns, e.g., power consumption and cellular data usage, since mobile device resources are constrained, and users prefer to minimize such costs. In this work, we propose a mobile video streaming framework over MPTCP (mDASH) to reduce the costs of energy and cellular data usage while preserving feasible streaming quality. Our evaluation results show that by utilizing knowledge about video behavior, mDASH can reduce energy consumption by up to around 20%, and cellular usage by 15% points, with minimal quality degradation.