• The Journal of Information Systems
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• v.23 no.3
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• pp.47-71
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• 2014

The purpose of the present study is to verify the structural relationship among system quality, information quality, service quality, perceived ease of use, perceived usefulness, satisfaction, intention on continuous use of mobile learning in cyber university. For this study, W cyber university in Korea was chosen to conduct web survey. The subjects were 283 students who participated in W's cyber university courses. A hypothetical model was composed of system quality, information quality, service quality, perceived ease of use and perceived usefulness as exogenous variables, satisfaction and intention on continuous use of mobile learning as endogenous variables. The result of this study through structural equation modeling analysis is as follows: First, information quality only affect satisfaction, Second, perceived ease of use, perceived usefulness and satisfaction significantly affect intention on continuous use of mobile learning. These results imply that information quality should be considered for the design and development of mobile learning contents. Also, perceived ease of use, perceived usefulness and satisfaction is important to enhance intention on continuous use of mobile learning. This study proposes strategies for successful mobile learning in cyber university.

• Proceedings of the Korea Database Society Conference
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• 2010.06a
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• pp.5-12
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• 2010

With a sample of 147 Korean small and medium size companies, this study examined the relationships among degree of information orientation, corporate culture, degree of information management implementation and selected business performances in the process of implementing IMS improvement programs, such as IMS(Information Management System). Information orientation is defined as company-wide understanding and implementation of the underlying philosophy, principles, approached, and tools of information improvement programs. It is assumed that successful implementation of information improvement programs requires a information-oriented mind-set of the employees. The key elements of information orientation include continious improvement structured processes, organixation-wide participation and customer-focused spirit. Culture id defined as the value and beliefs of em organization that shape its behavior. It is also assumed that successful implementation of information improvement programs require strong support from s corporate culture that emphasizes cintinious improvement. Adopting the competing values model of Quinn and McGrath(1985), corporate culture is classified into 'flexible' versus 'controlled culture' and 'outer-directed' versus 'inner-directed culture'. Fitness was defined through the relationship between levels of information oriented and types of corporate culture. The results were as follows. First, it was found that when a company with high information orientation promoted information innovation programs, such as IMS, it reported higher degree of information management implementation and improvement in business performances. Second, the results showed the importance of 'flexible culture' and 'outer-directed culture' in performing information, innovation. Regarding the types of corporate culture, the analysis found that developmental culture, rational culture and group culture were effective. Third, companies with high information oriented and flexible culture or companies with high information orientation and outer-directed culture reported the highest implementation in Information management activities. Fourth, the results showed that the level of information management implementation had a mediating effect on the relationship between information orientation and business performance. It was also found that enhanced non-financial performance led to the improvement of financial performance. This study attempted to exaime the factor that lead information management program to success. In order to reach success, first, it is suggested that companies have positive mind set toward continious information improvement. Secondly, it is recommended that a flexible and outer-directed culture appropriate for continious information improvement is cultivated.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.2
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• pp.261-271
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• 2016

The need and interest for a successful operation of Information System in the defense industry have increased due to a rapid development in ICT. However, research on adderssing such increased demand has been minimal. This paper introduces a Success Model for IS in the defense field based on literature reviews, and proves the performance of the proposed model. The verification results show that the quality factors of IS have positive influence on perceived usefulness and user satisfaction. The results, as well, imply that perceived usefulness and user satisfaction improves the operational performance of IS. Therefore, this study proves that quality factors of IS increase the operational performance through perceived usefulness and user satisfaction. Through this research, the patterns of information utilization in the defense IS is understood, and the directions for improving the operational performance of IS is presented.

• IE interfaces
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• v.17 no.spc
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• pp.122-130
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• 2004

Since the cost of software maintenance occupies about 50~75% in a general successful organization, the software maintenance plays an important role in software life cycle. In particular, if the managed system needs to be operated in a long term or the system is very large and complex, then the maintenance is especially more important. Software maintenance is defined as software modification activities after customer delivery, such as improvement of performance or functionality, error correction, adaptation to environmental changes, etc. In this paper, software cost estimation models are proposed, that is based on productivity of manpower in maintenance projects. In order to do this, the activities of maintenance are classified into function change, non-function change, user support and application operation. The proposed models are constructed and verified based on the real size and cost information of projects in the real world. The approach in this paper is to discriminate the heterogeneous activities in maintenance projects, and then to calculate the respective cost of each discriminated activity. By using the proposed models, the total cost of maintenance project is summed from the costs of four activities. In addition the number of conflicts between owner and order receiver about the amount of cost will be reduced and the reasonable cost estimation system will be established.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.11a
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• pp.516-525
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• 2005

Case-based reasoning (CBR) has been widely used in various areas due to its convenience and strength in complex problem solving. Generally, in order to obtain successful results from CBR, effective retrieval of useful prior cases for the given problem is essential. However, designing a good matching and retrieval mechanism for CBR systems is still a controversial research issue. Most prior studies have tried to optimize the weights of the features or selection process of appropriate instances. But, these approaches have been performed independently until now. Simultaneous optimization of these components may lead to better performance than in naive models. In particular, there have been few attempts to simultaneously optimize the weight of the features and selection of the instances for CBR. Here we suggest a simultaneous optimization model of these components using a genetic algorithm (GA). We apply it to a customer classification model which utilizes demographic characteristics of customers as inputs to predict their buying behavior for a specific product. Experimental results show that simultaneously optimized CBR may improve the classification accuracy and outperform various optimized models of CBR as well as other classification models including logistic regression, multiple discriminant analysis, artificial neural networks and support vector machines.

• Journal of Internet Computing and Services
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• v.10 no.6
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• pp.81-98
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• 2009

Collaborative filtering, one of the most successful technologies among recommender systems, is a system assisting users in easily finding the useful information and supporting the decision making. However, despite of its success and popularity, one notable issue is incredibility of recommendations by unreliable users called shilling attacks. To deal with this problem, in this paper, we analyze the type of shilling attacks and propose a unique method of building a model for protecting the recommender system against manipulated ratings. In addition, we present a method of applying the model to collaborative filtering which is highly robust and stable to shilling attacks.

• Information Systems Review
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• v.10 no.2
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• pp.269-289
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• 2008

It is very difficult problem to estimate and evaluate the performance of e-government system which scope and size are large and its effectiveness can not be seen shortly but reveals after several years. It is because the previous offline processes can not be transformed to online ones fully and shortly. For such e-transformation cases, the performance evaluation model should be adjusted and modified gradually as time passes. This paper propose new EEM(E-transformation Evaluation Model) model and methodology to evaluate G2B system that is one of large e-government project. EEM model can derive monetary value of e-transformatized business process areas(online areas). It also estimate the expected effect of offline area that is not yet transformed to online. EEM model consists of standard model, verification model and estimation model with some variables such as evaluation year, evaluation area and data type. By using survey data and database data together it can validate the correctness of the model and derive the effect of the system introduction. This paper also propose EEM evaluation methodology consisting of 5 stages and 10 sub processes to evaluate online and offline effect efficiently. To show the usefulness of this study, we evaluate the performance of Korea G2B system named KONEPS which is famous as a successful e-government case in the world by using the proposed model and methodology. The proposed model and methodology can be applied to different similar areas including e-government projects and large scale information system introduction in private sectors. This study can be also used for establishing appropriate policies about e-government project and informatization issues.

• Journal of Korea Society of Industrial Information Systems
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• v.5 no.1
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• pp.47-52
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• 2000

This study objectively in examines materials related to factory rationalization of D Corp., a regionally based enterprise. One reason that previous factory rationalizations have not been all that effective is that each firm has not used strategies specially designed for it Despite the fact that each firm has a different culture, and different human and physical resources, the application of rationalization without any modifications has produced many problems. In order to stabilize the production system and reduce the capacity of the factory, D Corp. changed the basic 5 S's and stimulated the factory atmosphere through computer education. Rationalization stabilized and standardized the factory, and organized the physical resources and each area of the factory according to their place in the process of production. It also made improvements that verified the party responsible for the flow of the complex production system, and simplified analysis supervision of production, and ex post management. We think that the successful example of D Corp. can serve as a real, tangible model for small and medium regionally-based firms to follow.

• Knowledge Management Research
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• v.13 no.3
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• pp.79-103
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• 2012

Recently because the IS development project is large scale and complicated, the necessity of tools that can manage effectively smooth communications and the harmonized project between the interested parties is exposed. According to this fact, many companies are investing enough to the PMS (Project Management System) for the sake of the systematic management of the IS development project, and also this PMS is emerging as one of the indispensable tools for the successful IS development project by casting off from a auxiliary means for the past project management. However, as had been expected, whether the introduction of the PMS is possible to facilitate communications within a project team, and a main motivation that can derive individual performance and organizational performance that participated in the IS development project is induced or not are not verified still empirically and apparently. With respect to this, a survey was conducted to examine how PMS quality affected user satisfaction, communication, individual performance and project performance. The effects of the data gathered were verified by structural equation model analysis.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.07a
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• pp.121-125
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• 2003

In this paper, we propose a framework of Transmission Control Protocol with Software Rejuvenation methodology, which is applicable for network system survivability. This method is utilized to improve the survivability because it can limit the damage caused by successful attacks. The main objectives are to detect intrusions in real time, to characterize attacks, and to survive in face of attacks. To counter act the attacks' attempts or intrusions, we perform the Software Rejuvenation methods such as killing the intruders' processes in their tracks, halting abuse before it happens, shutting down unauthorized connection, and responding and restarting in real time. These slogans will really frustrate and deter the attacks, as the attacker can't make their progress. This is the way of survivability to maximize the deterrence against an attack in the target environment. We address a framework to model and analyze the critical intrusion tolerance problems ahead of intrusion detection on Transmission Control Protocol (TCP).