• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.8
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• pp.768-775
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• 2011

Since error compensation schemes guaranteeing high reliability are required in wireless communication systems for the transmission of the large amount of data, as an efficient error compensation scheme the turbo HARQ scheme combining automatic repeat request and turbo coding has been studied in many places in the literature. In the case of conventional turbo HARQ schemes, the transmitter recognizing NAK signals repetitively sends the whole unit packet to the receiver although the received packet can be partially correctable. Through two successive processes, selection of uncorrectable error data and retransmission of only the relevant parts of the information data, transmission efficiency can be improved. In this paper, we present an error data selection criterion for retransmission using the sign transitions of A Posteriori values and propose a tubo HARQ scheme based on the partial retransmission technique. Through a computer simulation, we show and analyze the performance of the proposed scheme with transmission efficiency.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.145-149
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• 2011

우리나라의 강우특성은 여름철인 6월~9월에 집중되며 대부분이 일시에 집중적으로 발생하여 하천을 통하여 호소 및 바다로 유입된다. 이러한 강우특성으로 여름철에 집중되는 강우로 인한 하천의 유량을 댐과 같은 수공시설물을 통해 저류시킴으로써 하류지역의 홍수피해를 예방하고 이용할 수 있는 물을 안정적으로 확보할 수 있도록 하고 있으나 대형 인공호의 유역에서는 인구 증가와 상업 및 공업화에 따른 토지이용이 변화함에 따라 오염물질의 유입이 증가하고 있는 추세이다. 댐이나 호소는 지표면에 고여 있는 수체를 말하며 물이 천천히 흐르거나 흐름이 전혀 없는 경우도 있다. 댐이나 호소에서는 장기간 수류의 지체현상이 발생하므로 발생하는 수체 및 수질의 문제가 하천과는 다르다고 할 수 있다(서동일 등, 2009). 호소의 물은 정체되어 있기 때문에 흐르는 물에 비해 자정능력이 부족하고 바닥에 퇴적된 유기물이 분해되어 수질에 나쁜 영향을 미치기 때문에 수질관리에 여러 가지 어려움이 따른다(박석순, 2009). 따라서 흐름방향 보다 수심방향으로의 특성이 강하게 작용하는 댐이나 호소에서는 3차원 수리 수질 모형의 적용이 타당하며 본 연구에서는 이를 위하여 EFDC를 적용하였다. 섬진강 유역의 경우 전체유역의 65.8%가 임야로 이루어진 산림유역으로 비교적 적은 양의 유역오염물질이 발생하지만 산불이나 벌채와 같은 산림의 손실은 홍수기 때 유역오염물질의 발생 및 유출을 증가시켜 주변수체의 수질을 악화시킬 우려가 있다. 이에 본 연구에서는 운암호 수질측정망 상류 유역면적인 $526.23km^2$에 대하여 토지변화 시나리오를 임야의 25%, 50%, 75%가 손실되어 나대지화 되었다고 가정하고, EFDC 모형을 이용하여 산림지역의 소실에 따른 토지피복 변화가 섬진강 댐 운암호의 수질에 미치는 영향 정도를 파악하였다.

• Journal of Practical Engineering Education
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• v.12 no.1
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• pp.231-242
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• 2020

The purpose of this study was to investigate educational needs for development of principals' strategic leadership. The researcher analyzed 128 responses from elementary and secondary school principals who participated in professional development programs in 2019. For data analyses, the researcher conducted t-test and Borich needs assessment and drew the Locus for Focus model. Results are as follows. First, all respondents and secondary school principals considered important competencies data collection and use for setting future directions, vision statement for educational community, preparation of essential values for educational activities in school, evaluation on school finance and utilization, effort for development of school system, and enhancement of positive communication climate. Second, elementary school principals regarded important competencies as vision statement for educational community, preparation of essential values for educational activities in school, analysis of school environment and use, evaluation on school finance and utilization, investigation of educational objectives and planning, effort for development of school system, and enhancement of positive communication climate.

• Clean Technology
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• v.18 no.2
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• pp.144-154
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• 2012

Technology trends of coal gasification were studied through patent analysis. The patents published or registered in Korea, U. S. A., Japan and Europe, and administered by the World Intellectual Property Organization from mid 1970s to 2010 were analyzed based on the application tendency, patent share, major applicants and their activity indices, and market power, etc. Japan and U. S. A. led the patent activities in the early phase of technology development, but major applicants had been diversified globally since 2000. Portfolio analysis revealed that the technology was under developing period. The analysis showed that the most active R&D had been focused on gasifier development. Technology competitiveness was analyzed via indices such as cites per patent, patent impact index, technology strength and patent family size, etc. Key patents were extracted through quantification based on patent family size and cites per patent. The technology flow was figured out to reveal the technology trends.

• Korean Journal of Ichthyology
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• v.20 no.4
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• pp.291-302
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• 2008

Seasonal variation of species composition in the coastal waters off Wangdol-cho were investigated using the catches by gill net and trammel net from 2002 to 2004. A total of 58 species was collected and classified into 15 orders and 34 families. Of the 58 species identified, Scorpaeniformes and Perciformes accounted for 62.1% of the species. 35 species in 11 orders and 22 families were collected by gill net and 51 species in 15 orders and 30 families were collected by trammel net. The number of species was high in summer and autumn and lowest in winter. Catches were correlated with sea water temperature. The numbers of individuals and their biomass were 5,295 inds. and 1,890 kg, with the highest values achieved in summer and the lowest in spring. The most dominant species were Pleurogrammus azonus and Gadus macrocephalus. The seasonal species community showed a high similarity between summer and autumn.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.134-137
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• 2016

Big data analysis refers the ability to store, manage and analyze collected data from an existing database management tool. In addition, extract value from large amounts of structured or unstructured data set and means the technology to analyze the results. Meta-analysis is a statistical integration method that delivers an opportunity to overview the entire result of integrating and analyzing many quantitative research results. Meta-analysis is sometimes expressed as an analysis of another analysis. Commonly, factors of metabolic syndrome can be defined as abdominal obesity, high triglycerides, low high density lipoprotein cholesterol, elevated blood pressure, and elevated fasting glucose. This study will find meaningful mediator variables for criterion variables that affect before and after the metabolic syndrome studies, on the basis of the results of a meta-analysis. We reviewed a total of 5 studies related to metabolic syndrome published in Korea between 2000 and 2016, where a cause and effect relationship is established between variables that are specified in the conceptual model of this study.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.181-188
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• 2020

This study was conducted to identify the optimal conditions for seedling growth in Veronica rotunda var. subintegra (Nakai) T.Yamaz. which a endemic plant and can be development as ornamental plants. We sowed V. rotunda var. subintegra (Nakai) T.Yamaz. seeds, and exposed the seedling was different treatment conditions. We varied soil type and fertilizer concentration, shading ratio, additional fertilizer concentration, pretreatment light exposure and collection time of seeds. We found that seedling growth was good in horticultural substrate (with no additional fertilizer), but mixed soils supplemented with fertilizer inhibited growth, regardless of the fertilizer concentration. In the 55% shading treatment, seedling growth was greater than in the non-shading treatment. High concentration addition of fertilizer (Hyponex) promoted plant growth, in terms of both plant length and fresh weight. Exposure of seeds to a red light-source prior to germination had a greater effect on seedling growth than exposure to other light sources. Seedlings exhibited better growth when grown from seed collected in 2018, rather than 2017.

• Journal of The Korean Association of Information Education
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• v.22 no.1
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• pp.131-140
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• 2018

The KAIE computing system curriculum consists of information equipment, operating systems, and information and communication fields, and covers basic understanding and principles of computer science. The role of the teacher is important to achieve the curriculum achievement standards. Therefore, we examined the factors affecting the teaching capacity of the KAIE computing system curriculum. The results of this study show that the teaching methods of teachers through the literacy of information and communication technology have a statistically significant effect on the teaching competency of the computing system curriculum. Also, male teachers perceived higher perceived factors than female teachers. The differences in teaching competency between teacher groups of less than 5 years and less than 5~10 years were significant. Based on these results, it is necessary to develop collaborate SW teaching strategies and mentor - centered training programs that can strengthen ICT and SW professors' competence and encourage participation of low - career teachers and female teachers.

• Journal of the Korean Geotechnical Society
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• v.27 no.11
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• pp.27-37
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• 2011

A series of centrifuge model tests to investigate the suction pile pullout loading capacity in sand have been performed. The main parameters that affect the pullout loading capacity of a suction pile include the mooring line inclination angle and the padeye position of the suction pile. With respect to the padeye position, the maximum pullout loading capacity is obtained when the padeye position is near 75% of the pile length from the top. The direction of the pile rotation changes when the padeye position reaches somewhere near 50~75% for all mooring line inclination angles. The translation displacement of suction pile to develop the time of maximum pullout loading capacity decreased as the mooring line inclination angle increased. In addition, the vertical displacements of the center of a suction piles for all cases appeared to develop toward the ground surface.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.291-291
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• 2018

하천 및 수자원의 효율적인 관리와 더불어 다양한 수공구조물의 운영 및 관리를 위해서 구조물 주변에서 발생하는 불연속 흐름 및 급변류 등의 현상과 구조물 운영을 반영한 수치해석 기법을 이용한 모델 개발의 중요성이 커지고 있다. 본 연구에서는 하천의 불연속 흐름을 모의하기 위한 1차원 흐름해석 모형(K-River)을 개발하였다. 본 모형은 천이류와 급변류를 수치적으로 안정하게 처리하기 위하여 지배방정식을 보존형 Saint-Venant 방정식으로 선정하고, FVM과 Forward Euler 방법을 이용하여 이산화를 수행하였다. 수치흐름률을 계산하기 위해서 불규칙 단면과 하상의 급경사 등에 신뢰도가 높은 기법으로 판단되는 근사 Riemann해법 중 하나인 HLL flux를 이용하였다. 개발된 K-river 모형의 검증을 위해서 해석해가 존재하는 타원형의 하상융기가 있는 하도에 적용하였으며, 국내에서 하천 설계 및 관리를 위해서 광범위하게 이용되고 있는 1차원 흐름해석 모형인 FDM기반의 HEC-RAS 모의결과와 비교 검토를 수행하였다. 그 결과, FDM기법에서는 모의되지 않는 일부 급변류 패턴을 개발 모형을 통해 모의가능하였으며, 전체적으로 K-River가 기존 모형 보다 해석해에 근사한 결과를 나타내었다. 또한, 배수문을 비롯하여 합류부, 분류부, 펌프장, 암거 등이 설치되어 운영되고 있는 아라뱃길에 적용하여 K-River의 적용성을 평가하였다. K-River를 이용하여 아라뱃길의 흐름분석을 수행한 경우가 HEC-RAS를 이용한 경우보다 수위와 유량의 유동을 시간에 따라 세밀하게 모의하였으며, 이는 배수효과에 의한 파의 전달이 FDM기법 대비 정확히 모의되기 때문으로 판단된다. 추후 연구에서는 현재보다 시간간격을 상세화 하여 수집된 관측수위를 통해 추가적인 검증을 수행하고, 다양한 특성을 가진 타 하천 등에 적용하여 모형의 적용성을 확대하고자 한다.