• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11B
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• pp.1225-1233
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• 2009

ISPs and Enterprises are equipping their networks with sufficiently high speed facilities and provide large bandwidths members. However the high speed enterprise network does not have satisfying end-to-end network performance within the network in spite of under utilization. The root cause of this performance degradation is a micro-congestion, which is a short-live event of traffic congestion. A micro-congestion causes packet loss, delay and packet reodering, and finally results in end-to-end network performance degradation. In this paper, we propose a micro-congestion detection method and find out the characteristics of performance degradation by analyzing traffic archives which is collected from a network link when a micro-congestion occurs.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.110-113
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• 2008

태양광 발전은 태양에너지를 직접 전기에너지로 변환시키는 설비로서 Co2 발생이 적고 에너지원인 태양에너지가 무한하다는 장점이 있다. 현재 EU를 비롯한 선진국 및 개도국에서는 신재생에너지 확대를 위해 전 국가적으로 노력하고 있으며 특히 태양광 발전분야는 전 세계적으로 설비용량이 급증하고 있다. 국내에서도 발전차액지원제도 하에 태양광 발전설비를 확충하고 있으며, 정부가 발표한 1차국가에너지 기본계획에 의하면 2030년까지 3,504 MW로 공급규모를 확대할 방침이다. 그러나 현재 태양광 발전은 에너지 변환효율은 약 15%이며 날씨와 시간에 따라 발전에 제약이 따른다. 이에 태양광 발전의 신뢰성을 확보하기 위해 국내 발전차액지원을 받고 있는 태양광 발전소의 연간 발전량을 근거하여 이용률을 분석했다. 분석결과 일사량이 풍부한 전남지역의 이용률이 가장 높고,반대로 경기와 서울지역은 저조했으며, 연평균 15.70%의 이용률을 보였다. 한편 월간 이용률은 5월에 높게 나타났으며, 연중 최대 전력수요가 나타나는 7-9월에는 기상조건으로 인해 저조한 이용률을 보였다. 따라서 기후변화를 완화하고 저탄소 녹색성장을 구현하기 위해 기술개발을 통해 태양광 이용률 증대시켜야 한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.10 no.16
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• pp.7-18
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• 1987

From birth to death, every man is under the control of the three biorhythm curves that initiate from inner body. Those are called physical rhythm emotional rhythm and intellectual rhythm. These biorhythms have influence each other in human behaviour like physical endurance, creativity, record of examination. The result of investigation indicates that the students' records in low level period are lower than those of in high. Therefore, it is verified statistically whether the biorhythem has effects on human ability in scholarly record or not And also, this research calculates the average mixed biorhythm which is representable for a group by using mode mixed-biorhythm.

• Journal of the Korean Society for Library and Information Science
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• v.37 no.2
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• pp.169-186
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• 2003

Most of the university libraries in Korea provide digital reference service(DRS), but the use of DRS is very low. The low usage of DRS seems to result from the lack of subject librarians, of staff, of public relations, and of managers' enthusiastic attitude and understanding of DRS. It is difficult to solve these problems because of the poor circumstances in universities. The collaborative digital reference service(CDRS) is a solution to these problems. Not only CDRS costs little but also can provide reference services in many different subject areas. Though subject specialist librarian, user-friendly system interface, system programs and administrative supports are necessary to implement CDRS, the education and training of the subject specialist librarians is the most important work to be done in the university library situation in Korea.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.13 no.1
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• pp.85-92
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• 2002

Objectives：This study was conducted to compare the memory function among the attention deficit/hyperactivity disorder(ADHD), the learning disorder(LD) and the comorbidity disorder(ADHD+LD) groups. Methods：Thirty-four children(11 ADHD, 5 LD, 9 ADHD+LD, and 8 Psychiatric control) were individually assessed using the KEDI-WISC and Memoty Assessment Scale(MAS), and then the results of those test were analyzed. Results：In memory test, all of three group showed lower performances than control group. The comorbidity, the LD and the ADHD group showed lower scores in almost subtests of MAS respectively. The good performance in memory test was significantly correlated with the types of memory strategy and error response children used during testing. Discussion：The clinical utility of the memory test like MAS was discussed in terms of differential diagnosis for ADHD, LD and ADHD+LD children.

• Korean Journal of Medicinal Crop Science
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• v.2 no.3
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• pp.219-226
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• 1994

Immature ovule of intergeneric $F_1$ hybrid between Platycodon grandiflorum x Codonopsis lanceolata for producing embryogenic callus. somatic embryos and plant regeneration were cultured in vitro on various medium as well as MT(Murashige Tucker)medium treated with different concentration of plant growth regulators. Embryogenic callus induction was highest in the treatment of NAA 0.5 $mg/{\ell}$ and zeatin 0.01 $mg/{\ell}$ added on MT medium, whereas it was lower in treatments with auxins alone. MT medium were more effective in production of somatic embryos from incubated embryogenic callus. Most favorable plant growgh regulator for producing somatic embryos was 2. 4-D 0.5 $mg/{\ell}$ and zeation. BAP 0.01$mg/{\ell}$, but hormone-free and auxins alone were less effective. NAA 0.01$mg/{\ell}$ added with zeation 0.5 $mg/{\ell}$ was effective as high as NAA 0.01 $mg/{\ell}$ alone in normal plant regeneration from somatic embryo.

• Korean Journal of Plant Tissue Culture
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• v.24 no.1
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• pp.43-48
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• 1997

Apical meristems of Wasabia japonica were cultured on Murashige and Skoog's medium supplemented with cytokinins alone or together with 1.0 mg/L IAA. Shoot initials could be induced from leaf primordia on apical meristems. Calli and roots were formed on the medium containing cytokinins and 1.0 mg/L IAA in combination after 30 days of culture, but there were no callus proliferation. Shoot organogenesis began after 60 days of culture and these small shoots elongated when transferred to a medium containing 1.0 mg/L BA or kinetin. Shoots were formed directly without callus induction from apical meristems all the explants on the medium containing cytokinins variously, and most of the shoots proliferated multiple shoots which could be divided to obtain plantlets. Shoot multiplication rate in response to cytokinins was best on the medium containing 1.0 mg/L BA or 2.0 mg/L zeatin. Divided plantlets rooted well on MS medium containing 0.01 mg/L IBA after 15~30 days of subculture and the rooted plantlets developed into whole plants with multiple shoots. After rooting, the regenerated plants were washed and transferred to the pots containing sterilized soil.

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.211-217
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• 2014

A metabolomic study using GC/MS analysis was conducted to identify key metabolic components regulating the growth of open-pollinated Pinus koraiensis families, which were grown for 29 years at three different locations. Among 110 individual metabolites identified, the contents of 62 metabolites were higher in the superior than in the inferior families (p<0.05), together with 22 metabolites, such as phosphoric acid, alanine, glycine, malic acid, and sucrose, being accumulated 1.5-fold higher in the superior families. In addition, 15 metabolites including alanine, malic acid, sucrose, d-turanose, and succinic acid showed positive correlation with the growth (p<0.01). Furthermore, the metabolites, of which contents were correlated with the growth but not significantly changed at different locations, were acetic acid, succinic acid, butanoic acid, glutamic acid, and inositol. Therefore we suggest that several metabolites selected in this study may be used as metabolic markers for quantitative growth trait in P. koraiensis.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.3
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• pp.83-92
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• 2004

A continuous monitoring of textural characteristics of surface sediments, sedimentation rates and beach profile was carried out to investigate the seasonal variations of sedimentary processes in the Imjado beach, southwestern coast of Korea for two years. The beach profiles consist of steep beach face and relatively flat middle and low tide beaches. The slope of the beach face increases in summer and decreases in winter, in good accordance with the standard beach cycle. Ridge and runnel systems are well developed in the middle and low tide beaches during the summer, but these structures are replaced by mega-ripples during the winter. The sediments are fining southward as well as landward. The mean grain-size tends to be increasingly coarser during seasons of autumn and winter on the north beach and during seasons of winter and spring on the south one. In addition, the sediments are eroded on the north beach and accumulated on the south one as a whole. These are probably due to southward transportation of the sediments as long-shore current (NE-SW) runs around the coastal line of the beach. However, the seasonal variations in accumulation rates are very complex and irregular. It is considered that the Imjado beach represents in non-equilibrium state, as a result of coastal and submarine topographic changes by artificial agents and sea-level uprising associated with global warming.

• Korean Journal of Environmental Biology
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• v.24 no.2 s.62
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• pp.201-211
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• 2006

55 zooplankton taxa including 35 copepoda were observed in the Uldolmok waterway during the sampling period from August 2003 to April 2004. Neritic species showed the seasonal species fluctuation, and oceanic warm-water species occurred throughout the year. The number of taxa tended to increase at the flood tide from low tide to high tide, and to decrease at the ebb tide from high tide to low tide. Therefore, species composition of zooplankton in the Uldolmok waterway seemed to be affected by the inflow of oceanic waters with oceanic species all the year round. Total abundance of zooplankton ranged from 104 (February 2004) to 2,717 indiv. $m^{-3}$ (August 2003). According to the tidal cycle, the change of total abundance was more irregular and variable in November 2003 and February 2004 than August 2003 and April 2004. In August 2003 and April 2004, total abundance was low at the strong tide, and was high at low and high tide when tidal current was weak. Average abundances of dominant species such as Paracalanus indicus, Cirripedia nauplii and Acartia hongi were on the order of twice higher at ebb tide than flood tide. However, their abundances were also subject to wide fluctuation within flood tide and ebb tide. The changes of environmental parameters such as water temperature, salinity and chlorophyll-a concentration were negligible along the tidal periods in the Uldolmok waterway. Therefore, the advection, transfer and loss of zooplankton population derived from strong tidal current and eddy formed by the local difference of tidal velocity lead temporal variation of zooplankton community more complex and variable in the Uldolmok waterway.