• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.3
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• pp.195-202
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• 2015

NHPP software reliability models for failure analysis can have, in the literature, exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, finite failure NHPP models that assuming the expected value of the defect and infinite failures NHPP models that repairing software failure point in time reflects the situation, were presented for comparing property. Commonly used in the field of software reliability based on exponential power distribution software reliability model finite failures and infinite failures were presented for comparison problem. As a result, finite fault model is effectively infinite fault models, respectively. The parameters estimation using maximum likelihood estimation was conducted. In this research, software developers to identify software failure property some extent be able to help is considered.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.2
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• pp.345-352
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• 2014

As the utilization rate of smart device increases, various applications for smart device have been developed. Since these applications can contain important data related to user behaviors in digital forensic perspective, the analysis of them should be conducted in advance. However, lots of applications get to have new data format or type when they are updated. Therefore, whether the applications are updated or not should be checked one by one, and if they are, whether their data are changed should be also analyzed. But observing application data repeatedly is a time-consuming task, and that is why the effective method for dealing with this problem is needed. This paper suggests the automatic system which gets updated information and checks changed data by collecting application information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.115-119
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• 2006

The channel is one of the precious and limited resources in wireless networks. There are many researches on the channel management. Recently, the optimization problem of guard channels has been an important issue. In this paper, we propose an intelligent channel management technique based on the neural networks. An SRN channel alteration model is developed to generate the learning data for the neural networks and the performance analysis of system. In the proposed technique, the neural network is trained to generate optimal guard channel number g, using backpropagation supervised learning algorithm. The optimal g is computed using the neural network and compared to the g computed by the SRN model. The numerical results show that the difference between the value of g by backpropagation and that value by SRN model is ignorable.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.99-103
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• 2006

In this paper, we focus on the problem of designing an energy efficient MAC protocol for wireless sensor networks and analyze S(Sensor)-MAC and T(Time-out)-MAC. S-MAC is based on the concept of the 'listen/sleep mode cycle'. This applies message passing to reduce contention latency for sensor-network applications that require store-and-forward processing as data moves through the network. However unlike the S-MAC, where the duration of the cycle is fixed, T-MAC introduces an adaptive duty cycle in a novel way: by dynamical ending the active part of it. This reduces the amount of energy wasted on idle listening, in which nodes wait for potentially incoming messages while still maintaining a reasonable throughput. In this paper we discuss the design of these two Protocols. We analyze them from the aspect of latency, throughput, and power savings when using the OMNeT++ simulator in various environments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1568-1576
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• 2015

This paper proposes a prediction reputation system for the anti-SPIT solution in real-time VoIP environment. Increased accuracy of the determination as to whether spam or not by deriving a threshold based on SPIT presence in the existing paper. The existing schemes need to get the user's feedback and/or have experienced the time delay and overload as session initiates due to real-time operation. To solve these problems, the proposed scheme predicts the reputation through the statistical analysis based on the period of session initiation of each caller and the call duration of each receiver. As per the second mentioned problem, this scheme performs the prediction before session initiation, therefore, it's proper for real-time VoIP environment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.301-307
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• 2006

As container traffic in the world increases rapidly, size if containership is become bigger and bigger. With these trends, many studies have. been done on such big ships by consultant, naval architects, port designers, ship operators, economists etc,. with different points of view and results. But previous studies were concentrated on hardware and theoretical side. Therefore the objective of this paper is to analyze response and intention of ship's user such as shipping companies and forwarding companies about prospects of mega-ship size, preference of Mega ship, problem and handling time of Mega ship.

• Journal of Navigation and Port Research
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• v.37 no.2
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• pp.181-186
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• 2013

In a corporate financing, the decision of optimal capital structure is becoming more critical issues and still remaining a problem to be solved though many of researcher have studied. Particularly, shipping companies need a huge amount of capital finance for new vessel's capacity and then they are considering what is the best capital structure. In this point of view, this study tries to investigate the determinants of debit maturity structure focused on the Korean shipping industry. As results of panel regression analysis, firm size, liquidity, chance of growth, good cash flow are major determinants of debit expiration structure in the Korean shipping companies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2865-2874
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• 2013

Recently, most of movies top-ranked in the box office are screening in Stereoscopic 3D, and the world's leading electronics companies such as Samsung and LG are getting the hots for 3DTV sales. However, each person has different binocular disparity and different viewing distance, and thus he or she feels the severe visual fatigue and headaches if he or she is watching 3D content with the same binocular disparity, which is very different from things he or she feels in the real world. To solve this problem, this paper proposes and implement a 3D rendering system that correct the disparity of 3D content by reflecting binocular distance and viewing distance. Then, the computational complexity is analyzed. Optical-flow and Warping algorithms turn out to consume 732 seconds and 5.7 seconds per frame, respectively. Therefore, a dedicated chip-set for both blocks is strongly required for real-time HD 3D display.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1227-1239
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• 2015

The purpose of this study was to identify alcohol status and related factors of drinking problems among Residents at Permanent Rental Apartments in Incheon. Data was collected from 20 August 2012 to 28 September 2012, and the 663 subjects were analyzed using SPSS 18.0. The data was analyzed by using descriptive statistics, chi-square test and logistic regression. As a result of survey, alcohol consumption was low, but prevalence of alcohol was high. From the logistic regression analysis, age(less than 40), unmarried, drinking reason for habituation, insomnia, anxiety, unemployed and interpersonal relationships were associated with in drinking problems of the residents of permanent rental apartments. Considering of these variables, the future research is necessary to provide an individual approach based on problem drinking level as well as to provide a proactive approach and policy development for of permanent rental apartment residents.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.6
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• pp.448-459
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• 2004

Interoperability is an important requirement of portable storage devices that are used to exchange and share data among diverse hosts. However, the required interoperability cannot be provided if different host systems use different file systems. To address this problem, we propose a new type of storage device called FSOC(File System On a Chip) that contains the file system within the storage device. In this paper, we give an example of the design and implementation of a flash memory-based FSOC and propose the performance models of the conventional storage device and the FSOC. We also analyze the performance characteristics of the conventional storage device and the FSOC based on the proposed performance models, and provide several experimental results using real applications that validate the performance models.