• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.141-144
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• 2011

최근 이기종 멀티프로세서 시스템에서의 병렬화를 위해 범용 CPU 와 다른 컴퓨팅 장치들간의 다양한 연동 기술들이 부각되고 있다. 멀티프로세서 프로그래밍 모델인 OpenMP 는 가장 널리 사용되는 병렬 프로그래밍 언어이지만 기존 OpenMP 의 작업 할당 정책으로는 프로세서간 로드밸런싱을 문제를 해결할 수 없다는 한계점을 가지고 있다. 본 논문에서는 기존 OpenMP 의 작업할당 문제를 해결할 수 있는 알고리즘을 제안한다. 제안하는 알고리즘은 SMP(Symmetric Multi Processing) 구조뿐만 아니라 AMP(명령어 구조는 같으나 동작 속도가 다른 이질 멀티프로세서 구조)에서도 작업부하균형을 효과적으로 실행할 수 있다.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.34-35
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• 2009

• International Journal of Knowledge Content Development & Technology
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• v.9 no.4
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• pp.47-68
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• 2019

The study investigates the utilization of open access repositories for visibility of academic publications by lecturers in South-East, Nigeria. The specific objectives were to investigate the types of academic publications available, platforms used in self-archiving, level of satisfaction derived by lecturers with the contribution of open access repositories, challenges and strategies. It adopted descriptive survey design. Proportionate stratified sampling technique was used to draw a sample size of 418 from the total population of 4,187 lecturers. Questionnaire and observation check list were used for data collection. Frequency count, percentage, and mean score were used to analyze the data. The study revealed that there are enough academic publications available such as books, journals, projects, and thesis with the exception of handouts. It also revealed that Google Scholar, Research Gate and Open Access Journal were the main platforms lecturers use in self-archiving; while other platforms like Institutional Repositories, among others were minimally employed. Lecturers are less satisfied with the contribution of open access repositories. All the suggested challenges such as inadequate power supply, poor network, lack of awareness and inadequate research grants were all accepted. Similarly, all the suggested strategies for improving them were accepted. Recommendations were made based on the findings such as more awareness creation on importance of open access repositories; re-training of lecturers and provision of adequate ICT infrastructures that will improve the utilization of open access repositories by lecturers which could enhance the global visibility of academic publications from the Nigerian Universities.

• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.1025-1042
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• 2002

The goal of this study is to generate a structured document which improves the performance of an information retrieval system by using thesaurus, information on relations between words (terms), and to study on the technique for searching this structured document. In order to accomplish this goal, we propose a DODI (Depth -Oriented Decomposition Index) technique for the structured document and an algorithm to search for related information efficient]y through this index technique that uses a thesaurus. We establish a storage system by which the structured document generated by this index technique is saved in a database through OpenXML and XML documents are generated through ForXML methods.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.1
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• pp.38-45
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• 2021

The photovoltaic module has the characteristic of changing its output characteristics depending on the amount of radiation and temperature, where the arrays that connect them in series and parallel also have the same characteristics. These characteristics require the MPPT technique to find the maximum power point. Existing P&O and IncCond cannot find the global maximum power point (GMPP) for partial shading. Moreover, in the case of Improved-GMPPT and Enhanced Search-Skip-Judge-GMPPT, GMPP due to partial shading can be found, but the variation in the open voltage during temperature fluctuations will affect the operation of the Skip and will not be able to perform accurate MPPT operation. In this study, we analyzed the correlation between voltage, current, and power under solar module and array conditions. We also proposed a technique to find the maximum power point even for temperature fluctuations using not only the amount of radiation but also the temperature coefficient. The proposed control technique was verified through simulations and experiments by constructing a 2.5 kW single-phase solar power generation system.

• Wind and Structures
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• v.15 no.1
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• pp.27-41
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• 2012

Wind loads on low-rise buildings in general and residential homes in particular can differ significantly depending upon the laboratory in which they were measured. The differences are due in large part to inadequate simulations of the low-frequency content of atmospheric velocity fluctuations in the laboratory and to the small scale of the models used for the measurements. The imperfect spatial coherence of the low frequency velocity fluctuations results in reductions of the overall wind effects with respect to the case of perfectly coherent flows. For large buildings those reductions are significant. However, for buildings with sufficiently small dimensions (e.g., residential homes) the reductions are relatively small. A technique is proposed for simulating the effect of low-frequency flow fluctuations on such buildings more effectively from the point of view of testing accuracy and repeatability than is currently the case. Experimental results are presented that validate the proposed technique. The technique eliminates a major cause of discrepancies among measurements conducted in different laboratories. In addition, the technique allows the use of considerably larger model scales than are possible in conventional testing. This makes it possible to model architectural details, and improves Reynolds number similarity. The technique is applicable to wind tunnels and large scale open jet facilities, and can help to standardize flow simulations for testing residential homes as well as significantly improving testing accuracy and repeatability. The work reported in this paper is a first step in developing the proposed technique. Additional tests are planned to further refine the technique and test the range of its applicability.

• Journal of KIISE
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• v.42 no.10
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• pp.1254-1267
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• 2015

Recently, excessive installations of APs have caused WLAN interference, and many techniques have been suggested to solve this problem. The AP aggregation technique serves to reduce active APs by moving station connections to a certain AP. Since this technique forcibly moves station connections, the transmission performance of some stations may deteriorate. The AP transmit power control technique may cause station disconnection or deterioration of transmission performance when power is reduced under a certain level. The combination of these two techniques can reduce interference through AP aggregation and narrow the range of interferences further through detailed power adjustment. However, simply combining these techniques may decrease the probability of power adjustment after aggregation and increase station disconnections upon power control. As a result, improvement in performance may be insignificant. Hence, this study suggests a scheme to combine the AP aggregation and the AP transmit power control techniques in OpenFlow-based WLAN to ameliorate the disadvantages of each technique and to reduce interferences efficiently by performing aggregation for the purpose of increasing the probability of adjusting transmission power. Simulations reveal that the average transmission delay of the suggested scheme is reduced by as much as 12.8% compared to the aggregation scheme and by as much as 18.1% compared to the power control scheme. The packet loss rate due to interference is reduced by as much as 24.9% compared to the aggregation scheme and by as much as 46.7% compared to the power control scheme. In addition, the aggregation scheme and the power control scheme decrease the throughput of several stations as a side effect, but our scheme increases the total data throughput without decreasing the throughput of each station.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.1
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• pp.1-7
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• 2010

Detecting data races is important for debugging programs with OpenMP directives, because races result in unintended non-deterministic executions of the program. It is especially important to detect the first data races to occur for effective debugging, because the removal of such races may make other affected races disappear or appear. The previous tools for race detecting can not guarantee that detected races are the first races to occur. This paper suggests a tool what detects the first races to occur on the program with nested parallelism using the two-pass on-the-fly technique. To show functionality of this tool, we empirically compare with the previous tools using a set of the synthetic programs with OpenMP directives.

• Knee surgery & related research
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• v.30 no.4
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• pp.275-283
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• 2018

Purpose: To compare the clinical outcomes between the open posterior approach and arthroscopic suture fixation for displaced posterior cruciate ligament (PCL) avulsion fractures. Methods: A literature search was performed on MEDLINE, EMBASE, and the Cochrane Library databases. The inclusion criteria were as follows: papers written in English on displaced PCL avulsion fractures, clinical trial(s) with clear description of surgical technique, adult subjects, a follow-up longer than 12 months and modified Coleman methodology score (CMS) more than 60 points. Results: Twelve studies were included with a mean CMS value of 72.4 (standard deviation, 7.6). Overall, 134 patients underwent the open posterior approach with a minimum 12-month follow-up, and 174 patients underwent arthroscopic suture fixation. At final follow-up, the range of Lysholm score was 85-100 for the open approach and 80-100 for the arthroscopic approach. Patients who were rated as normal or nearly normal in the International Knee Documentation Committee subjective knee assessment were 92%-100% for the open approach and 90%-100% for the arthroscopic approach. The range of side-to-side difference was 0-5 mm for both approaches. Conclusions: Both arthroscopic and open methods for the treatment of PCL tibial-side avulsion injuries resulted in comparably good clinical outcomes, radiological healing, and stable knees.

• Tuberculosis and Respiratory Diseases
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• v.72 no.3
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• pp.261-274
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• 2012

For decades, the standard technique for tracheostomy was the open, surgical technique. However, during the past 20 years, the use of percutaneous dilatational tracheostomy has been increased and shown to be a feasible and safe procedure in critically ill patients. The purpose of this report is to review the percutaneous dilatational tracheostomy technique, describe the role of bronchoscopy as guidance for the procedure, and identify the available evidences comparing percutaneous dilatational tracheostomy to surgical tracheostomy.