• Journal of KIISE:Computer Systems and Theory
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• v.30 no.5_6
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• pp.290-298
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• 2003

Internet-based computer systems have to provide both high-availability and high-performance. Cluster technology has been used to obtain availability and performance simultaneously Generally, high-availability cluster systems tolerate a failure of a cluster node and cost-effectively solve it. In this paper, we study availability and downtime cost of (n,k) cluster systems. By considering performance, we model state transition of (n,k) cluster systems and apply software rejuvenation technique to improve availability of the system. We find that software rejuvenation can be used to improve availability of (n,k) cluster systems.

• Journal of the Korea Society of Computer and Information
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• v.24 no.6
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• pp.81-88
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• 2019

Based on the theory of planned behavior and the theory of legal deterrence, this study takes consumers' willingness to pay for digital music as the research object, investigates the consumers who have digital music consumption channels and behaviors, and discusses the willingness of consumers to pay for digital music and its influencing factors. The study attempts to achieve the following research purposes: First, explore the influencing factors of willingness to pay for digital music using domestic and foreign literature research and related content analysis. Second, we want to examine the effect of Attitude, Collective Specifications, Quality Sensitivity and Music affinity on willingness to pay. Third, Legal deterrence and resource availability tries to verify whether there is a moderating effect between Attitude, Collective Specifications, Quality Sensitivity and Music affinity and willingness to pay. The research data was collected in 2019 between April 6th to May 8th. Questionnaires were randomly distributed in fixed places, mainly in Hubei Province, China. A total of 393 questionnaires were selected for data analysis. Based on the previous theoretical review and empirical analysis, the study draws the following conclusions: Firstly, attitude, collective specifications, quality sensitivity and music affinity have an impact on the willingness to pay. Second, Legal deterrence has a regulatory effect on the relationship among quality sensitivity, musical affinity and the willingness to pay. Last the resource availability has a significant impact on the willingness to pay. It also has a regulatory effect on the relationship among quality sensitivity, music affinity and the willingness to pay.

• Journal of Korean Library and Information Science Society
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• v.13
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• pp.131-166
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• 1986

This study is designed to review the methods of duplicate copies decision making in the academic library. In this thesis, I surveyed queueing & markov model, statistical model, and simulation model. The contents of the study can be summarized as follows: 1) Queueing and markov model is used for one of duplicate copies decision-making methods. This model was suggested by Leimkuler, Morse, and Chen, etc. Leimkuler proposed growth model, storage model, and availability model through using system analysis method. Queueing theory is a n.0, pplied to Leimkuler's availability model. Morse ad Chen a n.0, pplied queueing and markov model to their theory. They used queueing theory for measuring satisfaction level and Markov model for predicting user demand. 2) Another model of duplicate copies decision-making methods is statistical model. This model is suggested by Grant and Sohn, Jung Pyo. Grant suggested a model with a formula to satisfy the user demand more than 95%, Sohn, Jung Pyo suggested a model with two formulars: one for duplicate copies decision-making by using standard deviation and the other for duplicate copies predicting by using coefficient of variation. 3) Simulation model is used for one of duplicate copies decision-making methods. This model is suggested by Buckland and Arms. Buckland considered both loan period and duplicate copies simultaneously in his simulation model. Arms suggested computer-simulation model as one of duplicate copies decision-making methods. These methods can help improve the efficiency of collection development and solve some problems (space, staff, budget, etc, ) of Korean academic libraries today.

• Structural Monitoring and Maintenance
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• v.5 no.1
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• pp.79-92
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• 2018

The evaluation theory of reliability, availability, maintainability and safety (RAMS) as a mature theory of state evaluation in the railway engineering, can be well used to the evaluation, management, and maintenance of complicated structure like the long-span bridge structures on the high-speed railway. Taking a typical steel-truss arch bridge on the Beijing-Shanghai high-speed railway, the Nanjing Dashengguan Yangtze River Bridge, this paper developed a new method of state evaluation for the existing steel-truss arch high-speed railway bridge. The evaluation framework of serving state for the bridge structure is presented based on the RAMS theory. According to the failure-risk, safety/availability, maintenance of bridge members, the state evaluation method of each monitoring item is presented. The weights of the performance items and the monitoring items in all evaluation levels are obtained using the analytic hierarchy process. Finally, the comprehensive serving state of bridge structure is hierarchical evaluated.

• The Journal of Information Systems
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• v.27 no.2
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• pp.197-219
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• 2018

Purpose The purpose of this study is to examine what motivates users to adopt one of the emerging applications for collaborative consumption of sharing economy. Using the self-determination theory, motivation theory and TAM(Technology Acceptance Model) as the theoretical framework, this study illustrates important factors that influence adoption of collaborative consumption service. We develops the ICTs(Information and Communications Technologies) initiatives and motivation model to collaborative consumption. Design/methodology/approach This paper makes use of a quantitative methodology using survey questionnaire that allows for the measurement of the eight constructs(System Availability, Contents Quality, Design & Personalization, Security & Privacy, Emotional & Social Value, Economic Value, Attitude, Adoption & Consumption) contained in the hypothesized theoretical model on the basis of the prior literatures. Data collected from a sample of 227 respondents who have used the collaborative consumption services and provided the foundation for the examination of the proposed relationships in the model. Findings This study has the following implications for the users and providers of CC platforms and services. The ICTs initiatives (System Availability, Contents Quality, Design & Personalization, Security & Privacy) are the influential factors that motivate the emotional and social value to CC. On the other hand, The ICTs initiatives (System Availability, Contents Quality) are not very significant factors of economic value to CC. The empirical analysis result indicate that there are significant causal effect among emotional & social value, economic value, and adoption to CC. This study provides important theoretical implications for innovation adoption research through an empirical examination of the relationship between ICTs initiatives, motivation factors to collaborative consumption in the sharing economy.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.9
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• pp.445-453
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• 2003

As cluster systems used for high performance computing consist of large number of running servers, one has to solve the low availability problems occurred by the high chance of the server failures. To handle the problems, it is necessary to have the precise definition of available performance of cluster systems that represents availability and performability of the systems simultaneously. Previous research results that mention availability issues lack for concerning system performance such as waiting time and response time in their availability definition. In this paper, we propose a new availability metric for (n, k)-way cluster systems which compose of n primary servers and k backup servers. With the metric, the change of system performance according to arrival rates is captured and the waiting time of a request can be kept below to a certain level. Using various system operating parameters, we calculate availability and downtime of cluster systems along with waiting tine deadline.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.49-54
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• 2010

In these days, Internet environment are very quickly development as well On-line service have been using a online for the mission critical business around the world. As the amount of information to be processed by computers has recently been increased there has been cluster computing systems developed by connecting workstations server using high speed networks for high availability. As a result, this study on a cluster based DBMS and common solution of DBMS venders has been studying with a wide range, as well as It is not good study a management skill for the cluster-based DBMS efficiently and optimization. accordingly, This study find out optimization managements skill and theory of he High availability solution on cluster-based DBMS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.7
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• pp.2589-2609
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• 2021

Segment routing (SR) is a highly implementable approach for traffic engineering (TE) with high flexibility, high scalability, and high stability, which can be established upon existing network infrastructure. Thus, when a network failure occurs, it can leverage the existing rerouting methods, such as rerouting based on Interior Gateway Protocol (IGP) and fast rerouting with loop-free alternates. To better exploit these features, we propose a high-performance and easy-to-deploy method SRUF (Segment Routing under Uncertain Failures). The method is inspired by the Value-at-Risk (VaR) theory in finance. Just as each investment risk is considered in financial investment, SRUF also considers each traffic distribution scheme's risk when forwarding traffic to achieve optimal traffic distribution. Specifically, SRUF takes into account that every link may fail and therefore has inherent robustness and high availability. Also, SRUF considers that a single link failure is a low-probability event; hence it can achieve high performance. We perform experiments on real topologies to validate the flexibility, high-availability, and load balancing of SRUF. The results show that when given an availability requirement, SRUF has greater load balancing performance under uncertain failures and that when given a demand requirement, SRUF can achieve higher availability.

• Journal of the Korean Home Economics Association
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• v.28 no.3
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• pp.147-160
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• 1990

Family researchers had devoted little attention to Choice, Exchange theory by the time 1960. Being anchored by Thibaut & kelley(1959), this theory becomes one of the most widely used theoretical frameworks for family research. Waller's(1938) famous rating-dating hypothesis was intrinsically an exchange formulation. Blood and Wolfe(1960) employed the concept of rewards in their theory of family power. Farber(1964) also used the reward concept in his theory of permanent availability. Heer's(1964) specific application of its concepts to spousal power was among its earliest uses in the family. The general principle or most general proposition of the theory is that humans avoid costly behavior and seek rewarding statuses, to the end maxmize profits. This review will attempt to show that Choice, Exchange theory is applicable to the several arenas of family interaction and that it can provide an explanation for family behavior. Subjects such as mate selection, marital unstability, family cohesion, spousal power, the problems of aged, family co-unseling, and so on are included. By discussing research findings from a perspective of rewrds and costs this review will show that the application of the theory is not limited to one or two substative specialities with in the family domain. After all Choice, Exchange theory is truly general and can be productively applied to any domain of human behavior.

• Asia pacific journal of information systems
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• v.26 no.1
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• pp.66-79
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• 2016

The availability of detailed data on customers' online behaviors and advances in big data analysis techniques enable us to predict consumer behaviors. In the past, researchers have built purchase prediction models by analyzing clickstream data; however, these clickstream-based prediction models have had several limitations. In this study, we propose a new method for purchase prediction that combines information theory with machine learning techniques. Clickstreams from 5,000 panel members and data on their purchases of electronics, fashion, and cosmetics products were analyzed. Clickstreams were summarized using the 'entropy' concept from information theory, while 'random forests' method was applied to build prediction models. The results show that prediction accuracy of this new method ranges from 0.56 to 0.83, which is a significant improvement over values for clickstream-based prediction models presented in the past. The results indicate further that consumers' information search behaviors differ significantly across product categories.