• KIISE Transactions on Computing Practices
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• v.23 no.8
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• pp.459-465
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• 2017

Although the performance of computer hardware is increasing due to the development of manycore technologies, software lacking a proportional increase in throughput. Functional languages can be a viable alternative to improve the performance of parallel programs since such languages have an inherent parallelism in evaluating pure expressions without side-effects. Specifically, Haskell is notably popular for parallel programming because it provides easy-to-use parallel constructs based on monads. However, the scalability of parallel programs in Haskell tends to fluctuate as the number of cores increases, and the garbage collector is suspected to be the source of this fluctuations because it affects both the space and the time needed to execute the programs. This paper uses the tuning tool, GC-Tune, to improve the scalability of the performance. Our experiment was conducted with a parallel plagiarism detection program, and the scalability improved. Specifically, the fluctuation range of the speedup was narrowed down by 39% compared to the original execution of the program without any tuning.

• Journal of Advanced Navigation Technology
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• v.13 no.2
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• pp.214-223
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• 2009

In this paper, we analysed and simulated the high speed mobile wireless channel for IEEE802.11p WAVE/DSRC standard draft. IEEE802.11p working group measured and suggested 6 channel model for WAVE/DSRC systems which is used for vehicle to vehicle or vehicle to infra communication. However, the models only provides numerical model, it did not provide Computer based software simulation model. So it can not be used directly for performance estimation of WAVE system. In this paper we suggested simulation technique of WAVE channel simulation which is developed S/W based WAVE channnel simulator. The simulation results for PSD, LCR, and AFD are also obtained, which can be used for performance estimation of IEEE802.11p based vehicular communication system.

• Journal of KIISE:Software and Applications
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• v.31 no.12
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• pp.1660-1671
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• 2004

This paper proposes a method for measuring document similarity between two documents. One of the most significant ideas of the method is to estimate the degree of similarity between two documents based on the frequencies of terms and term-pair, existing in both the two documents. In contrast to conventional methods which takes only one feature into account, the proposed method considers several features at the same time and meatures the similarity using a neural network. To prove the superiority of our method, two experiments have been conducted. One is to verify whether the two input documents are from the same document or not. The other is a problem of information retrieval with a document as the query against a large number of documents. In both the two experiments, the proposed method shows higher accuracy than two conventional methods, Cosine similarity measurement and a term-pair method.

• Journal of KIISE:Software and Applications
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• v.27 no.4
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• pp.384-392
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• 2000

As a software becomes more complicated and large-scaled, it is very important for a software engineer to analyze user's requirements precisely and apply them effectively in the development stage. Due to the growth of the internet, the necessity of requirements elicitation and analysis in distributed environments has also become larger. This paper proposes a requirements elicitation supporting system that offer the basis for effectively analyzing requirements collected in distributed environments. The proposed system automatically categorizes collected requirements sentences into selected subject fields by measuring their similarity using a similarity measurement technique. Therefore, it reduces the difficulties in the initial stage of requirements analysis and it supports rapid and correct requirements analysis. This paper verifies the efficiency of the proposed system in similarity measurement techniques through experiments, and presents a process for requirements specifications elicitation using the embodied system

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1077-1083
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• 2012

SDO(Software Development Outsourcing) projects have been consistently increasing and expanding but also have many failures. In order to improve SDO performance, the factors affecting SDO performance are investigated in this study. SDO has relational risk as well as performance risk in nature, and the factors affecting the SDO performance caused by these mixed risks are drawn from the prior studies. With field survey targeted client IS personnel who experienced SDO, 214 survey questionnaires are collected and analyzed. Research results show that vendor power, client requirements certainty, goal clarity and goal alignment affect the SDO performance. However, vendor knowledge and client knowledge do not have much effect on SDO performance. The results of this study can be effectively utilized to decrease the failures of SDO and increase the possibility of success.

• The Journal of the Acoustical Society of Korea
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• v.23 no.2
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• pp.117-124
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• 2004

In this paper, we have been implemented the QPSK-based underwater transmission systems using DSP in order to transmit the underwater image data. We have adopted a BDPA (Block Data Parallel Architecture) to control multiple DSPs used in the transmitter and receiver in order to transmit the image data in real-time. We also have developed GUI software in order to drive and to debug the implemanted system in real-time. We have executed open sea tests in order to analyze the performance of the implemented system at East Sea near Kosung in Kangwon-Do. As a result of these experiments, it has been demonstrated that 10 kbps image data can be received without errors at 30m and 80m depth points, while the distance between the transmitter and the receiver is up to 20m.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1229-1236
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• 2009

Puretone audiometer, which is a machine used for measuring the minimum hearing threshold, can be cost-effectively implemented using computer with sound card and software. In this paper, we describe a puretone audiometer which has been designed and implemented based on a general PC with sound card. It supports air conduction and bone conduction test taking with automatic masking. It also provides multiple modes consisted of self-test, auto-test and manual test mode. Such multiple modes makes it possible to use in various environments like as home and/or hospital. Through measure of waveform of output voltage and sound pressure, we verified that puretone audiometer of this paper properly operates.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.3076-3082
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• 2010

The techniques and the products which use various video compression codec are come out from army or civil field. In existing high-end PC environment, process of the video compression codec does not become a problem, but in embedded system environments which limited system resources, because the system load due to the high-resolution images compressed by high-density, issues of performance and utilization are highlighted. This paper proposes the DirectShow Filter interfaces which are a hardware method in order to solve the problem existing software algorithms for image compression performance and peripheral interfaces.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.1
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• pp.19-26
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• 2010

In this paper, we adopt Storage Class Memory, which is next-generation non-volatile RAM technology, as part of main memory parallel to DRAM, and exploit the SCM+DRAM main memory system from the dependability perspective. Our system provides instant system on/off without bootstrapping, dynamic selection of process persistence or non-persistence, and fast recovery from power and/or software failure. The advantages of our system are that it does not cause the problems of checkpointing, i.e., heavy overhead and recovery delay. Furthermore, as the system enables full application transparency, our system is easily applicable to real-world environments. As proof of the concept, we implemented a system based on a commodity Linux kernel 2.6.21 operating system. We verify that the persistence enabled processes continue to execute instantly at system off-on without any state and/or data loss. Therefore, we conclude that our system can improve availability and reliability.

• Journal of KIISE:Software and Applications
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• v.35 no.3
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• pp.169-178
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• 2008

Cancer patients have been suffered from the instability of mind/body and unbalanced homeostasis because of cancer progression and medical treatment such as chemotherapy, It is very important that appropriated actions can be promptly taken by monitoring cancer patients' mental conditions. For this reason, it is crucial to develop a monitoring method which is convenient and not harmful to their body. Brain-computer-interface(BCI) system is introduced for the purpose in this paper. Prefrontal brain waves of cancer patients and control groups have been measured by a portable neurofeedback(NF) system based on self-regulation of the human electroencephalogram(EEG). The NF system consists of the portable EEG amplifier and a headband with dry electrodes placed on Fp1 and Fp2 sites. Patterns of the prefrontal brain waves taken by computer are correlated to brain quotients by EEG-analysis program. Basic rhythm quotient, attention quotient, emotional quotient, anti-stress quotient and correlation quotient of control group have shown high significant level compared with the cancer patients group. On the other hand, the EEG patterns analysis is shown its possibility to be an important methodology of monitoring cancer patients' condition.