• Journal of KIISE:Computer Systems and Theory
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• v.28 no.8
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• pp.390-398
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• 2001

인터넷을 이용한 서비스와 산업이 급속도로 발전하면서 인터넷 서비스를 위한 효율적이며 확장성이 있는 고가용성 시스템이 매우 중요한 요소로 인식되고 있다. 인터넷 서비스를 위한 고가용성 시스템은 컴퓨터들이 쉬지 않고 서비스를 제공할 수 있는 active-active 형태로 구성되어야 하며, 확장성을 위해서 N개의 컴퓨터가 연결되어 클러스터를 구성하는 N-way 방식을 지원하여야 한다. 본 논문에서는 N개의 컴퓨터들이 클러스터로 연결된 N-way에서 active-active 형태의 구성을 위한 알고리즘을 제시하고, 이를 바탕으로 구현된 고가용성 시스템인 Diehard를 소개한다. Diehard는 인터넷 서비스의 특성을 고려해서 소프트웨어 SPOF를 모니터링하고, 부분적인 서비스 중단에 대한 다양한 복구 정책 등을 지원하도록 설계 및 구현되었다.

• Journal of information and communication convergence engineering
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• v.18 no.4
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• pp.254-259
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• 2020

Phased-array antennas comprise a demanding antenna design methodology for commercial wireless communication systems or military radar systems. In addition to these two important applications, the phased-array antennas can be used in beamforming for wireless charging. In this study, a four-way analog beamforming front-end module (FEM) for a hybrid beamforming system is developed for 2.4 GHz operation. In a hybrid beamforming scheme, an analog beamforming FEM in which the phase and amplitude of RF signal can be adjusted between the RF chain and phased-array antenna is required. With the beamforming and beam steering capability of the phased-array antennas, wireless RF power can be transmitted with high directivity to a designated receiver for wireless charging. The four-way analog beamforming FEM has a 32 dB gain dynamic range and a phase shifting range greater than 360°. The maximum output RF power of the four-way analog beamforming FEM is 40 dBm (=10 W) when combined the four individual RF paths are combined.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.2
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• pp.39-48
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• 2023

Background: The position of pitcher requires a lot of repetitive motion, and because of this, it is known that not only professional baseball players, but also middle and high school players are frequently exposed to injuries in baseball. The purpose of this study is to examine the differences in upper extremity muscle activity during repeated pitching and the activity of each muscle during repeated pitching by analyzing middle and high school pitchers, divided into groups by age. Methods: Twenty participants (10 middle school male students and 10 high school male students) were recruited for this research. The outcome measures included neuromuscular motor control, including the upper trapezius (UT), triceps brachii (TB), deltoid (DT), latissimus dorsi (LD), biceps brachii (BB), pectoralis major(PM), extensor carpi radialis(ER), and flexor carpi radialis (FR). Results: The two-way analysis of varaince (ANOVA) was used to compare the muscle activity variables between the middle school and high school students. The one-way ANOVA was used to compare the muscle activity variables within time differences each groups. Conclusion: Our results provided promising clinical evidence that guide for upper extremity muscles to increase pitching efficiency in middle and high school base ball players.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.2
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• pp.185-192
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• 2014

Recombinant proteins can be generated quickly and easily in large amounts and at low-cost in silkworm larvae by using Bombyx mori nuclear polyhedrosis virus (BmNPV). We searched for high-permissive silkworm strains that have high production levels of heterologous proteins and are thus suitable for use as biofactories. In this study, we performed the analysis using a BmNPV vector expressing luciferase as a marker, and we confirmed protein expression by evaluating luciferase activity, determined by western blotting and luciferase ELISA, and confirmed transcription expression by semi- and quantitative real time PCR. For the selection of host silkworm strains, we first chose 52 domestic BmNPV sensitive strains and then identified 10 high-permissive and 5 low-permissive strains. In addition, to determine which hybrid of the high-permissive strains would show heterosis, nine strains derived through three-way crossing were tested for luciferase activity by western blotting, and luciferase ELISA. We found a correlation between luciferase activity and luciferase protein expression, but not transcription. There was no noticeable difference in protein expression levels between Jam313 as the high-permissive control strain and the three-way hybrid strains; however, the three-way cross strains showed lower luciferase activity compared with Jam313. In this study, luciferase protein production in the larvae of 52 domestic silkworm strains was elucidated using BmNPV.

• Korean Journal of Comparative Education
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• v.24 no.3
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• pp.1-23
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• 2014

The purpose of this study is to analyze some problems of general high school and provide some promotion ways of general high school in Gyeongsangbuk-do in long and short term perspective, considering necessity for consolidating educational capacity of general high school which is in disadvantage due to high school diversity and special high school promotion policy. For this, first, the study explores educational policy basis of Park Geun-hye's government, educational policy direction of Gyeongsangbuk-do, educational situation of general high school in Gyeongbuk area, and main contents of educational capacity consolidation way of general high school. Main tasks of Gyeongsangbuk-do general high school educational capacity reconsideration based on the educational capacity consolidation way of Ministry of Education are (1) enlargement of autonomy for formation and operation of focused curriculum by guidance, (2) enlargement of guidance and vocational education for general high school student, (3) consolidation of support program for student at risk, and (4) consolidation of support for general high school High-up program. For these main tasks are fixed and operated in school successfully, the fixation of school responsible management system based on geological environment and trait of each general high school, the application of whole quality control in school management, and the formation of cooperative school organizational culture should be constructed. And specific practice tasks and strategies for Gyeongsangbuk-do general high school educational capacity reconsideration (the cultivation of grobal democratic citizen, human being image in 2009 revised curriculum, and 'talented people with new thinking and genuine mind' of Gyeongsangbuk-do) are provided.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.9
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• pp.445-453
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• 2003

As cluster systems used for high performance computing consist of large number of running servers, one has to solve the low availability problems occurred by the high chance of the server failures. To handle the problems, it is necessary to have the precise definition of available performance of cluster systems that represents availability and performability of the systems simultaneously. Previous research results that mention availability issues lack for concerning system performance such as waiting time and response time in their availability definition. In this paper, we propose a new availability metric for (n, k)-way cluster systems which compose of n primary servers and k backup servers. With the metric, the change of system performance according to arrival rates is captured and the waiting time of a request can be kept below to a certain level. Using various system operating parameters, we calculate availability and downtime of cluster systems along with waiting tine deadline.

• Proceedings of the KOR-KST Conference
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• 1995.05b
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• pp.1-14
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• 1995

• Explosives and Blasting
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• v.12 no.3
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• pp.17-31
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• 1994

• Journal of the Korean Professional Engineers Association
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• v.24 no.2
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• pp.51-71
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• 1991

• Korean Circulation Journal
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• v.54 no.7
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• pp.407-408
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• 2024