• The Mathematical Education
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• v.43 no.4
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• pp.419-440
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• 2004

The purpose of this paper is to know the effects on number and operation abilities of the 1st grade children of elementary school by applying teaching and learning activity throught communication. For this purpose, we have studied according to the following procedure. 1. We divised teaching and learning model through communication and applied in the actual teaching and learning activity. 2. We investigated the effects of number and operations abilities of the 1st grade children by applying teaching and learning activity through communication. To accomplish this purpose, we applied learning activity through communication to the 1st grade of 40 elementary school children for about six months(September 1, 1999 ～ February 20, 2000). In process of applying this model, we collected all sorts of cases in the children's learning activity and investigated children's response on learning activity through communication, interview with children and researcher's observation. We applied the model through communication in class and compared with the traditional learning. 1. In learning through communication, children could solve the problem in themselves with a sense of responsibility. 2. It was impossible to find out the degree of children's comprehension in the explanatory learning. But in the learning through communication, it was a great help to individualize and plan the learning because children express their ideas clearly. It has conclusion as follows. The learning activity through communication has effected on forming number and operations abilities of the 1st grade of elementary school children importantly. 1. Children have improved in the abilities through communication to express their own ideas. 2. Children have studied with a sense of responsibility not in the teacher-oriented learning but in the self-directed learning 3. Children could find out the mathematical concepts in themselves - correcting false concepts, reguiding concepts by errors, finding invisible errors, solving problems variously and knowing the easy method. 4. The activity through communication in mathematics was a base of children's individual learning and important data of next learning plan. 5. The mathematical concepts formed through communication had a high transfer of learning. 6. Children have taken pleasure of discovery and had affirmative attitude about mathematics learning. We can make sure that number and operations abilities of the 1st grade children are formed by applying teaching and learning activity through communication. However, help and control of teacher have to be with it.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.6
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• pp.397-405
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• 2012

In this study, performance evaluation of newly developed technology for the economical and safe removal of volatile organic compounds (VOCs) coming out from electronic devices washing operation and offensive odor induction materials was made. Metal oxidization catalyst has shown 50% of removal efficiency at the temperature of $220^{\circ}C$. Composite metal oxidization catalyst applied in this study has shown that the actual catalysis has started at the temperature of $100^{\circ}C$. Comprehensive analysis on the catalyst property using Mn-Cu metal oxidization catalyst in the pilot-scale unit was made and the removal efficiency was variable with temperature and space velocity. Full-scale unit developed based on the pilot-scale unit operation has shown 95% of removal efficiency at the temperature of $160^{\circ}C$. Optimum elimination effective rates for the space velocity was found to be $6,000hr^{-1}$. The most appropriate processing treatment range for the inflow concentration of VOCs was between 200 ppm to 4,000 ppm. Catalyst control temperature showed high destruction efficiency at $150{\sim}200^{\circ}C$ degrees Celsius in 90~99%. External heat source was not necessary due to the self-heat reaction incase of VOCs inflow concentration is more than 1,000 ppm. Equipment and fuel costs compared to the conventional RTO/RCO method can be reduced by 50% and 75% respectively. And it was checked when there was poisoning for sulfide and acid gas.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.339-350
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• 2009

This study was carried out to investigate distributional condition of rare plants and useful plant resources, and to verify distributional patterns of understory vegetation associated with the upper layer's vegetation structure. Total 59 families, 160 genera, 218 kinds of vascular plants were identified at the study site including 6 rare plants designated by Korea Forest Service (Lloydia triflora Bak., Trillium kamtschaticum Pall., Lilium distichum Nakai, Anemone koraiensis Nakai, Iris odaesanensis Y.N. Lee, Viola diamantica Nakai). Twenty three species of useful plant resources were also identified at the site; 8 of them showed clustered distributions and the others were prone to scatter. Actual vegetation of this study area consisted of one natural community dominated by Quercus mongolica Fisch. and three disturbed communities of Larix kaempferi (Lamb.) Carriere, Abies holophylla Max. and/or a herbaceous vegetation resulting from forest removal and strong wind of mountain top. This classification was strongly supported by cluster analysis based on the surveyed plot data. Distributional patterns of understory vegetation within forest stand were somewhat related to overstory vegetation structure, but showed a different tendency according to site condition, species composition, and competitive pressure among understory vegetation. Therefore, in order to protect the important understory components as forest genetic resources, forest treatments such as density control of overstory should be implanted based on understanding of impact on understory's dynamics and growing condition.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.389-397
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• 2004

본 연구는 GIS를 이용하여 아파트 단지의 UHF대역의 전파장애에 대한 예측모델을 제시한다. 전파예측모델은 기지국 및 중계기 위치설계와 전파음영지역 결정 등 무선네트워크 서비스에 결정적으로 활용된다 기존의 전파예측모델은 한국지형요소나 3차원 공간기술이 반영되지 않고 외국지형기반의 2차원적인 접근으로 개발되어 있다. 특히 많은 사람이 거주하는 아파트단지에 대해서는 고려가 되어 있지 않은 실정이며, 마치 아파트 단지가 일반 건물로 취급되어 전파환경 요소로 분류되지 않은 상태이다. 그리고 전파관리자가 기존 전파 예측모델을 이용한 무선네트워크 설계 및 운용등에 있어 정확한 의사결정지원에 어려움이 많다. 본 연구는 이러한 한계와 문제점을 해결하기 위해서 아파트 단지의 전파에 대한 영향을 3차원 공간밀집, 건물높이, 전파의 전송방향에 대한 건물배치등 3가지 요소로 분류하고 GIS 도구로 그 요소들을 분석하였다. 그 결과로 상관과 회귀분석등 정량적인 방법으로 평가하여 아파트 전파예측모델(GARP)을 개발하여 다음의 결과를 얻었다. 첫째, 아파트 단지가 UHF 대역의 전파에 대한 영향은 전파진행방향성이 57%, 공간밀집이 30%, 건물높이가 13%의 순으로 나타났다. 둘째, 본 연구에서 개발된 아파트 모델은 기존 모델에 비해 평균 6.3dBm, 최소 2.15 ～ 최대 12.48dBm의 개선 효과가 있다. 셋째, 급속히 확산되는 도시 개발에 3차원 공간상에서 전파예측모델을 시뮬레이션하여 전파의 영향을 예측할 수 있으며, 대단지 아파트 건설과 전파환경영향평가의 기초정보 수집에 활용될 수 있다. 본 연구는 GARP모델과 GIS 가시권 분석기능을 이용하여 실제 지형공간상에서 전파경로 손실치를 도시화함으로써 전파관리자가 무선서비스지역 설계, 전파음영지역 판단, 최적 중계기와 기지국 위치 선정에 기여할 것으로 판단된다.하지 않은 지역과 서로 다른 분광특성을 나타내므로 별도의 Segment를 형성하게 된다. 따라서 임상도의 경계선으로부터 획득된 Super-Object의 분광반사 값과 그 안에서 형성된 Sub-Object의 분광반사값의 차이를 이용하여 임상도의 갱신을 위한 변화지역을 탐지하였다.라서 획득한 시추코아에 대해서도 각 연구기관이 전 구간에 대해 동일하게 25%의 소유권을 가지고 있다. ？스굴 시추사업은 2008년까지 수행될 계획이며, 시추작업은 2005년까지 완료될 계획이다. 연구 진행과 관련하여, 공동연구의 명분을 높이고 분석의 효율성을 높이기 위해서 시료채취 및 기초자료 획득은 4개국의 연구원이 모여 공동으로 수행한 후의 결과물을 서로 공유하고, 자세한 전문분야 연구는 각 국의 대표기관이 독립적으로 수행하는 방식을 택하였다 ？스굴에 대한 제1차 시추작업은 2004년 3월 말에 실시하였다. 시추작업 결과, 약 80m의 시추 코아가 성공적으로 회수되어 현재 러시아 이르쿠츠크 지구화학연구소에 보관중이다. 이 시추코아는 2004년 8월 중순경에 4개국 연구팀원들에 의해 공동으로 기재된 후에 분할될 계획이다. 분할된 시료는 국내로 운반되어 다양한 전문분야별 연구에 이용될 것이다. 한편, 제2차 시추작업은 2004년 12월에서 2005년 2월 사이에 실시될 계획이다. 수백만년에 이르는 장기간에 걸쳐 지구환경변화 기록이 보존되어 있는 ？스굴호에 대한 시추사업은 후기 신생대 동안 유라시아 대륙 중부에서 일어난 지구환경 및 기후변화를 이해함과 동시에 이러한 변화가 육상생태계 및 지표지질환경에 미친 영향을 이해하는데 크게 기여할 것이다.lieve in safety with Radioactivity wastes control for harmony with Environment.d by the experiments under vari

• Spatial Information Research
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• v.23 no.5
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• pp.53-64
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• 2015

Several countries have built National Spatial Data Infrastructure (NSDI) for information sharing among various fields. One of the important factors of NSDI is framework data, which is the most commonly used geospatial data across various fields. Previous studies on the framework data suggest components based on frequency survey and case study. However, such research methods do not have objectivity in setting the components of the framework data. This research uses factor analysis with 104 medium-level layers from the most widely used National Base Map and 5 layers from the other sources including cadastre and aerial image. Each layer is scaled with usage level as four different patterns of 1) background data, 2) reference data, 3) base data, and 4) other data, respectively. The analysis results show that the layers are grouped into 5 to 7 factors according to the patterns. ANOVA reveals that the mean differences between the factors with high values and the other factors with low values under each pattern are statistically significant. Such high value factors under each pattern consist of similar layers, close to identical, with those under the other categories. This research proposes framework data system, including transportation, building, hydrography, elevation, administrative district, digital orthoimagery, geodetic control, and cadastral based on the analysis results. Proposed framework in this research will be a basis of establishing spatial data sharing system. For sharing proposed framework data in various fields, these data must be established and distributed as actual standard and also related future researches should be performed.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.2
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• pp.63-72
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• 2016

Closed-circuit television(CCTV) is a facility that forms the backbone of the ubiquitous services provided by the Integrated Management Center of the Ministry of Land, Infrastructure and Transport and the Integrated Control Center of the Ministry of the Interior. However, it is installed and managed according to different laws, as it is operated and managed by each department. Moreover, because there are no regulatory grounds for unified management of CCTV, each municipality responsible for the actual management manages it based on the individual standards of each department. Thus, the purpose of this study is to develop a standardized management form to establish an integrated management plan. The author inspected the existing situation by examining the legal system and public data and through hands-on worker interviews, and discovered the managed element by reviewing the specifications of the bidding system. The management form for integrated management comprises the above requirements along with the management histories and linkage of intelligent facilities. A uniform management form for integrated management containing specifications of the CCTVs installed by various departments is created, and is easily searched for facilities to check requirements for joint use. The result of this study can contribute to building the database of facility management system for integrated management of facilities at the integrated management center as well as for a detailed simulation of the selection of location of CCTV depending on the CCTV's specifications.

• International Commerce and Information Review
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• v.15 no.4
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• pp.267-286
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• 2013

The WCO Time Release Study (TRS) is a unique tool and method for measuring the actual performance of Customs activities. The ultimate aim of TRS is to improve the performance of the function being measured. To be more specific, TRS is used for identifying bottlenecks in the international supply chain and/or constraints affecting Customs release, assessing newly introduced and modified techniques, procedures, technologies and infrastructure, or administrative changes, establishing baseline trade facilitation performance measurement, identifying opportunities for trade facilitation improvements and estimating the country's approximate comparative position as a benchmark tool. The effective utilization methods of TRS for trade facilitation in Korea Customs Services are as follows ; Firstly, it is necessary to make every efforts to identify bottlenecks in border-related procedures and improve their procedures for continuous and more improved trade facilitation. Secondly, it is necessary to optimize and simplify export-related procedures using the TRS in exportation for efficiency of total international supply chain. Thirdly, it is necessary to make coordinated border management with main trading partners. Lastly, it is necessary to enhance Korea's international status to support underdeveloped countries in the field of trade procedures.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.6
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• pp.42-48
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• 2002

The design, construction and performance test of a convenient multi-purpose irradiator is described. A multi-purpose irradiator using Cesium-137 has been developed for studies of low dose radiation effects in biology and for calibration of Thermo Luminescent dosimeter(TLD). During the operation, three rods of radioactive material which are 10cm in length revolve 180 degrees and irradiate biological samples, or TLD, and return to their shielded position, after the programmed time. A programmable Logic Controller(PLC) controls the sequence of operation, interlock, motor rotation and safety system. The rotation speed of biological samples can vary up to 20 RPM. A real time monitoring system was also incorporated to check and control the operation status of the irradiator. The capacity of the irradiation chamber was 4.5 liters. The isodose distribution at arbitrary vertical planes was measured by using film dosimetry. The dose-rate was 0.13 cGy/min in air and 0.11 cGy/min in water equivalent material in the case of Cesium-137. Range of activity was 2 Ci. The homogeneity of dose distribution in the chamber was ${\pm}$7%. The actual radiation level on the surface was within permissible levels. The irradiator had a maximum 0.35 mR/min radiation leakage on its surface.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.2
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• pp.117-144
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• 2013

The MOLIT is also establishing the flight safety standards for UAV within the current Aviation Law. Accordingly the required flight criteria includes operator location, mission operation limit, equipment, etc. which are the principle and standard applied based on the airspace use for UAV. Also, general flight rules, visual flight rules, instrument flight rules are required to be applied to the actual flight. Besides, an appliance regulation needs to be arranged regarding two-way communication, ATC and communication issue, airspace and area in-flight between UAS(Unmanned Aircraft System) users. An operation of the UAV in the air significantly requires the guarantee of the aircraft's capacity, and also the standardized flight criteria. A safe and smooth use is ensured only if this criteria is applied and understood by the entire airspace users. For the purpose, a standardized military UAV flight operations criteria and a law complementary scheme.

• Journal of the Korean Institute of Gas
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• v.21 no.6
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• pp.23-29
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• 2017

Solar and wind energy among the renewable energy produce irregular power because resource is difficult to control. When connected to grid have unstable. However, when the fuel cell system is connected to grid more stable because regular frequency and output power based on controllable hydrogen energy. To using fuel cell system in the household, it is important that the safety performance of power conditioning system(PCS) and it is important that evaluation method of electromagnetic compatibility(EMC). In this study, we consider that introduce power-frequency magnetic field immunity test before analyzed that compare with the EMC of the international standards and KGS AB 934 PC53. Also, we conduct that actual assessment and study on available the quantitative analysis as using complementary indicator.