• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.231-231
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• 2011

우리나라 수자원이용량의 47%를 차지하고 있는 농업용수는 공사관리지역(64%)와 지자체관리 지역(36%)으로 이원화 되어 있고, 공사관리지역은 2000년 이전 103개 농지개량조합이 개별적으로 관리하다가, 2000년 이후 농업용수의 효율적 관리를 위하여 2000년에 3개기관(농지개량조합, 농지 개량조합연합회, 농어촌진흥공사)이 통합하여 현재 한국농어촌공사가 되었다. 2000년 이전 103개 조합에서 저수지, 양배수장 등 수리시설물과 용배수로 등 평야부 시설물에 대한 각종 정보가 통합적으로 관리가 되지 못하였고, 매년 발간되는 농업생산기반정비사업 통계연보를 통해서 체계적인 관리가 되어왔다. 2000년 이후 통합 공사가 출범하면서 전국단위의 종합적이고 체계적인 정보관리가 가능해졌으나, 농업용수 정보(자료)가 개별 조합별로 산재되어 있고 전산화 되어 있지 못하였으며, 시설물의 설치년도가 오래된 경우 자료자체가 존재하지 않은 경우가 많이 있고, 소규모 시설의 경우 정보(자료)관리의 필요성에 대한 효용성에 대한 인식이 낮으므로 하여 농업용수관리 정보화에 많은 어려움이 있었다. 또한 기초적인 정보(자료)관리 구축이 되지 못한 상황에서 개별 시설물 또는 수계별로 이 치수관리를 위한 의사결정 지원시스템 구축에도 많은 어려움이 발생하였다. 이는 공사 내부 뿐만 아니라 외부의 우려와 비판이기도 하였다. 이러한 어려운 여건에도 불구하고, 우선 지난 10년 동안 농업용수관리의 기초적인 정보(자료) 관리 구축을 실시하여 수원공과 평야부 시설에 대한 정보구축을 실시하였고, 각 사업별로 RIMS, RAWRIS, TIMS, 지하수넷, UIRRI, 4대강상황실 등의 정보화 시스템을 구축하였다. Post 4대강, 유역통합관리 등 수자원환경의 내외적인 여건변화에 맞춰, 2010년 부터 개별 시스템에 대한 통합 농업용수관리 정보시스템 구축을 위한 마스터플랜을 수립하고 있고, 금번 마스터 플랜수립결과를 바탕으로 실질적인 시스템 구축을 완료하게 되면 명실상부한 농업용수분야의 최상위 시스템으로 자리매김 될 것이다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.11
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• pp.1084-1093
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• 2012

For large multihop networks, large time synchronization (TS) errors can accumulate with conventional methods, such as TPSN, RBS, and FTSP, since they need a large number of hops to cover the network. In this paper, a method combining Concurrent Cooperative Transmission (CCT) and Semi- Cooperative Spectrum Fusion (SCSF) is proposed to reduce the number of hops to cover the large network. In CCT, cooperating nodes transmit the same digitally encoded message in orthogonal channels simultaneously, so receivers can benefit from array and diversity gains. SCSF is an analog cooperative transmission method where different cooperators transmit correlated information simultaneously. The two methods are combined to create a new distributed method of network TS, called the Cooperative Analog and Digital (CANDI) TS protocol, which promises significantly lower network TS errors in multi-hop networks. CANDI and TPSN are compared in simulation for a line network.

• Journal for History of Mathematics
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• v.23 no.4
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• pp.101-122
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• 2010

Chinese Taipei won the first place at the mathematics achievement of TIMSS 2007. Especially, there was a significant difference in the percentage of correct answers between Chinese Taipei and Korea, and Chinese Taipei' percentage of correct answers was higher than Korea. This study compared the education system, mathematics instruction environment, and instructional activities of two countries. And for algebra, curriculum and textbooks were compared between two countries based on TIMSS 2007 framework. It was found that Chinese Taipei emphasized homework and test, and MCFL of that was low. Their textbook was formal, and induced the hasty abstraction, Also, some themes were introduced earlier than Korea and repeated across different grades.

• Journal of Bio-Environment Control
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• v.15 no.1
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• pp.107-113
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• 2006

These studies were carried out to investigate the quality of green tea processed by different pan-firing hand rolling and to select the best conditions during the procedure of green tea processing the results were as follows. At harvestion tea plant leaf, tea plants had 4 leaves. each leaf size was 7.5 cm'$\square$2.6 cm, and weight of 100 buds 46.6 g. The increase of pan-fired time decreased in the moisture content and yield of green tea. After processing green tea, 5 times pan-fired one had much more contents of total nitrogen (T-N:5.31%), caffeine (2.00%) and total amino acid (T.A.A. : 3,046 mg%) and less content of tannin (13.41%) than the other treatments. but 3 times pan-fired one had the highest contents of vitamin C (204.3 mg%) and chlorophyll (365.0 mg%) among three kinds pan-firing method. Sixteen kinds of free amino acid including theanine as a good taste component of pan-fired green tea were isolated and measured by HPLC. Free amino acid (FAA) contents were in the range of $2,683{\sim}2,925$ mg% and among various pan-firing methods, 5 tims pan-fired one had the highest content of F.A.A. Among these free amino acids, theanine occupied as much as $56.4{\sim}61.3%$ of F.A.A. Lightness, yellowness and redness of 5 times pan-fired green tea were middle value among three different treatments. Besides, it gained the highest score of sensory evaluation among them. These above results suggested that 5 times pan-fired green tea was considered to be the best level as pan-firing times of green tea processing.

• Nuclear Engineering and Technology
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• v.50 no.1
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• pp.140-144
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• 2018

Isotopic analyses of plutonium and low-enriched uranium mixtures with particle sizes of $0.6-3.3{\mu}m$ were performed using thermal ionization mass spectrometry with a continuous heating method to verify its effectiveness for the accurate analysis of minor isotopes without sample pretreatment. The mixed particles used in this study were prepared from a mixed solution of plutonium (SRM 947) and uranium (U010, $^{235}U$ 1% enriched) reference materials. The isotope ratios for plutonium in the individual mixed particles, including $^{238}Pu/^{239}Pu$, $^{241}Pu/^{239}Pu$ as well as $^{240}Pu/^{239}Pu$, and $^{242}Pu/^{239}Pu$, were in good agreement with the certified values despite the isobaric interference of $^{238}U$ and $^{241}Am$. The isotope ratios for uranium in the mixed particles also agreed well with the certified values within the range of error. However, the isotope ratios for minor isotopes, such as $^{234}U$ and $^{236}U$, in the particles with diameters of less than approximately $1.8{\mu}m$ could not be measured because numbers of $^{234}U$ and $^{236}U$ atoms in analyzed particles are too low. These results indicate that thermal ionization mass spectrometry with a continuous heating method is applicable for the analysis of trace amounts of plutonium isotopes, including $^{238}Pu$ and $^{241}Pu$, despite the presence of the respective isobars $^{238}U$ and $^{241}Am$ in the microsamples.

• Journal of The Korean Association For Science Education
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• v.21 no.2
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• pp.328-341
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• 2001

The purpose of this study was to analyze the achievements in science results of the TIMSS-R test, which was performed in 1999 with 38 nations participating. In this study, general trends in international science achievement considering the differences beween nation, content areas, and gender were analyzed through descriptive statics. The average scale score of Korean 8th grades students was 549, which was significantly higher than international average of 488. However it showed a relative decline from 4th grade in TIMSS to 8th grade in TIMSS-R. Chinese Taipei and Singapore students had the highest average performance, followed by Hungary, Japan, and Korea. The average gender differences of Korean students showed a decrease from TIMSS in 1995 to TlMSS-R in 1999, but it was still significantly higher than the international average. The average differences of overall science and each content area were not statistically significant both internationally and domestically.

• Journal of Conservation Science
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• v.34 no.1
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• pp.59-67
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• 2018

This study investigated manufacturing technique and provenance of the Gilt-bronze Seated Bhaisajyaguru (Medicine Buddha) Statue of Janggoksa Temple. The statue had the following : Cu(68.8%)-Sn(10.4%)-Pb(17.1%), it is similar to other medium or large Buddha statue. As results of comparison lead isotope ratio of sample with the provenance data were plotted in zone 3 of the South Korean galena map. According to this result of Bronze Buddha could be made into galena of the located in same area the temple. The results of this study were compared with the Bronze Bodhisattva statue of Goseongsa Temple. The manufacturing techniques were different based on the characteristics of Buddha statues and thus could be made into galena of the located in same area the temple.

• Analytical Science and Technology
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• v.13 no.4
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• pp.440-445
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• 2000

The techniques for manipulation of various micro-tools were essential for particle isolation and chemical analysis of micro-size particles. This report described the detailed techniques for the preparation and handling of several micro-tools. Presence of uranium particles in smeared filter paper were identified by using the solid track detector. The uranium particles were isolated using the micro-tools under the stereomicroscope and then transferred to the filament of TIMS for the determination of isotope ratios.

• 보존과학연구
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• s.32
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• pp.113-121
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• 2011

Four glass beads from Hakso-ri site, O'chang were analyzed for thirteen oxides with SEM/EDS and lead isotope ratios with TIMS respectively. These samples were classified to potash glass system($K_2O-CaO-SiO_2$) with HCLA(High CaO, Low $Al_2O_3$). However three samples with above 4% for lead could be classified to potash-lead ($K_2O-PbO-CaO-SiO_2$)glass system and it seemed that coloring agent for greenish blue was Cu. Lead isotope ratio data for four samples did not make a group but scattered to the space respectively. It needs more study for compositions and lead iosotope data of potash-lead glasses with regions and ages.

• Journal for History of Mathematics
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• v.25 no.4
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• pp.139-155
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• 2012

This study researched the trends of mathematics education in Korean mathematics class in the aspects of teaching and learning method, assessment and teachers' competency based on TIMSS 1995, 1999, 2003 and 2007. For the mathematics teaching and learning method, the differentiated instruction rate is higher. The activities focused on students not teacher are more, and frequencies of homework are higher but time spent for homework is less than the past. Especially, mathematics teachers link homeworks to instructions. And mathematics teachers uses more multiple choice items and more various assessment methods than the past. The average age of mathematics teachers tends to become older since 1995. The major of mathematics teacher are primarily mathematics and mathematics education. Korean mathematics teachers have less self-esteem for teaching mathematics contents and have more various interactions with peers. The rate of participating in-service training is more or less according to training contents.