• Journal of KIISE:Software and Applications
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• v.35 no.12
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• pp.731-740
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• 2008

A railway control system is one of the typical safety-critical systems. It is required to use formal methods for the requirements specification and verification in order to develop the global-standard railway control systems based on the computer systems. In this paper, we develop a guideline for requirements specification using formal methods, and present a case study of the development of a computer-based railway control system through the application of the proposed guideline. We use the Statechart and the Z method for the formal requirements specifications and verify the consistency and completeness of the formal specifications of the requirements.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.4
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• pp.345-355
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• 2022

Excellent employees are those who take on extra responsibilities and commitments at work. Hence, employees must pay attention to out-of-role activities that can help the company perform better. When a person takes on more responsibilities than he can handle, they will have to deal with the issue of work-family balance. This paper examines how the consistency of WFC affects employees' organizational citizenship behavior (OCB) using the Resource Conservation Theory. This study uses empirical research methodologies to assess 417 employees as a sample. (1) When the matches of work-to-family conflict (WFC) and family-to-work conflict (FWC) are consistent, the employee self-control resource depletion level is lower, and OCB is higher in the "high-high" consistency matching state. (2) The "low-high" match had a higher OCB than the "high-low" match when the WFC and FWC matches were inconsistent. (3) In the process of WFC affecting OCB, the depletion of self-control resources acts as a mediating factor. (4) Emotional intelligence plays a moderating role in the whole model. The lower the emotional intelligence was, the stronger the positive relationship between the consistency of WFC, FWC, and self-control resource depletion was.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.11
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• pp.974-978
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• 2013

AVI (Automatic Vision Inspection) systems automatically detect defect features and measure their sizes via camera vision. AVI systems usually report different measurements on the same defect with some variations on position or rotation mainly because different images are provided. This is caused by possible variations from the image acquisition process including optical factors, nonuniform illumination, random noises, and so on. For this reason, conventional area based defect measuring methods have problems of robustness and consistency. In this paper, we propose a new defect size measuring method to overcome this problem, utilizing volume information that is completely ignored in the area based defect measuring method. The results show that our proposed method dramatically improves the robustness and consistency of defect size measurement.

• Journal of Internet Computing and Services
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• v.4 no.6
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• pp.87-93
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• 2003

Data Replication makes distributed system and database system improved in availability and performance. But it is difficult to keep strict consistency in data update. Existing algorithms keep strict consistency, but have problems of cost a great deal and delay time. It is to introduce hybrid update propagation algorithm which permits eager update for original copy and propagates lazy update for other copies. Hybrid update propagation algorithm also permits group update in ownership. This algorithm menages replica version in order to control group update consistency. Consistency and performance is improved by combining eager update and lazy update with group ownership. Simulation shows improvement of transaction throughput and response time depending on application and execution environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.91-99
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• 2014

The main game architectures for multiplayer online games are the traditional client-server architectures, multi-server architectures and P2P(peer-to-peer) architectures. P2P architectures, due to their distributed and collaborative nature, have low infrastructure costs and can achieve high scalability as well as fast response time by creating direct connections between players. However, P2P architectures face many challenges. Distributing a game among peers makes maintaining control over the game more complex. These architectures also tend to be vulnerable to churn and cheating. Providing consistency control in P2P systems is also more difficult since conflicting updates might be executed at different sites resulting in inconsistency. In order to avoid or correct inconsistencies, most multiplayer games use a primary-copy replication approach where any update to the object has to be first performed on the primary copy. This paper presents the primary-copy model with the update dissemination mechanism that provides consistency control over an object in P2P architectures for multiplayer online games. The performance for this model is evaluated through simulation experiments and analysis.

• Journal of KIISE:Databases
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• v.31 no.2
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• pp.140-149
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• 2004

Data broadcast has received much attention as a very efficient method for disseminating data items in mobile environment with large number of mobile clients. In this approach, a database server periodically and continuously broadcasts data items through wireless channels and clients perform read-only transactions by accessing necessary data items from the air. While broadcasting, the server must also process update transactions on the database, which raises an obstacle for client's accessing consistent data. In this research, we propose a new algorithm SCDSC(Serialization Checking with DirtySet on Commit) which is an alternative for solving the concurrency control problem efficiently. The SCDSC is a kind of optimistic concurrency control in that a client checks the consistency of data using a DirtySet as a part of data broadcast when it commits its transaction. In each broadcast cycle, the server updates and disseminates the DirtySet with newly changed data items for last few cycles in the sliding window approach. We perform an analysis and a simulation study to evaluate the performance of our SCDSC algorithm in terms of data consistency and data currency.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.11b
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• pp.130-139
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• 1999

In order to manage the wet end chemistry on paper machines, our goal is to control sub-processes through which we can influence the entire wet end operations with maximum effect. The most important sub-processes are: consistency, ash, and chemistry. The management of these three main groups is based on on-line maesurements and automatic control. This paper presents a new wet end management platform, a new analyzer. This new analyzer utilizes a modular structure and modem software. It is part of a new paper machine concept. The controls of this concept are feedback and feedforward solutions that control retention, consistencies, ash, and charge, resulting in a more stable wet end (30...80%), more uniform paper, and better rnnability.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.7
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• pp.196-202
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• 1999

Recent trend changes a criterion for evaluation of burner that environmental problem is raised as global issue. For efficient driving problem, the higher thermal efficiency and the lower oxygen in exhaust gas, burner is evaluated the better. For environmental problem, burner must satisfy $NO_{X}$ limit and CO limit. Consequently, 'good burner' means on whose thermal efficiency is high under the constraint of $NO_{X}$ and CO consistency. To make existing burner satisfy recent criterion, it is highly recommended to develop feedback control scheme whose output is the consistency of $NO_{X}$ and CO. This paper describes development of real time flame diagnosis technique that evaluate and diagnose combustion state such as consistency of components in exhaust gas, stability of flame in quantitative sense. This study focuses on wave length of luminescence from chemical reaction measurement of the luminescence via optical measuring apparatus and derive correlation with consistency of components in exhaust gas by image processing technique.

• Journal of KIISE:Databases
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• v.31 no.5
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• pp.457-467
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• 2004

The efficiency of algorithms managing data caches has a major impact on the performance of systems that utilize client-side data caching. In these systems, two versions of data can be maintained without an additional space overhead of the server by exploiting the replication of data in the server's buffer and clients' caches. In this paper, we present a new cache consistency algorithm employing versions: Two Versions-Callback Locking (2V-CBL). Our experimental results indicate that 2V-CBL provides good performance, particularly outperforms a leading cache consistency algorithm, Asynchronous Avoidance-based Gache Consistency, when some clients run only read-only transactions.

• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.83-92
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• 2005

Computer-assisted motional analysis is a popular method in biomechanical studies. Validation of the specific system and its measurement are fundamental to its application in the areas. Because the accuracy and consistency of a particular system provide the researchers with critical information to assist in making judgements regarding the degree to which inferences can be drawn from measurement data. The purpose of this study was to assess the accuracy and consistency of the Kwon3D motion analysis system. Validation parameters were five lengths from eight landmarkers in combination with the DLT reconstruction error values, digitizing monitor resolutions, and numbers of control points. With the best setting, Kwon3D's estimations of 260cm, 200cm, 140cm, 100cm, and 20cm were $260.33{\pm}.688cm$, $199.98{\pm}.625cm$, $139.89{\pm}.537cm$, $99.75{\pm}.466cm$, $20.08{\pm}.114$, respectively. There was no significant DLT error value difference between two monitor resolutions, but 0.27cm significant difference in 260cm estimation. There were significant differences in 260cm and 200cm estimations between with 33-control-point DLT error and with 17-control-point DLT error, but no in 140cm, 100cm, and 20cm estimations. Test-retest results showed that Kwon3D measurements were highly consistent with reliability coefficients alpha of .9263 and above.