• Korean Journal of Organic Agriculture
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• v.19 no.2
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• pp.229-243
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• 2011

Consumers' interest and government's support for the fruits rapidly increased organic fruit productions. This study was examined to compare the soil physicochemical and microbial properties of orchards soil in conventionally and organically management systems. Organic cultivation had lower soil bulk density, solid phase, and penetration resistance than the conventional cultivation. Soil pH and organic matter contents increased from March to August, and the values were greater in the organic cultivation than the conventional cultivation. Total nitrogen (N) and phosphorous concentrations decreased from March to August, and the organic soils had greater N but lower phosphorous concentrations than the conventional soils. Soil microbial carbon biomass increased 36% and 15% for organic and conventional cultivations, respectively, from March to August. Soil microbial N biomass was greater in June than March or August, and the organic cultivation had a greater biomass N compared to the conventional cultivation. Soil dehydrogenase and chitinase activities were greater in June than in March or August. ${\beta}$-glucosidase activity declined in both cultivations, while the phosphatase activity increased. Organic cultivation had greater enzyme activities in March, June, and August, except for the acid phosphatase activity in June.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.05a
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• pp.202-204
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• 2018

2018년 현재 한국과학기술정보연구원(KISTI)은 계산과학공학 플랫폼 기반으로 온라인 시뮬레이션이 가능한 EDISON(EDucation-research Integration through Simulation On the Net) 서비스를 제공하고 있다. 해당 플랫폼 서비스는 7개 전문분야(전산의학, 전산설계, 전산열유체, 구조동역학, 계산화학, 나노물리, 도시환경)의 학생 및 연구자들이 학습 및 시뮬레이션을 실행하고 결과를 활용할 수 있도록 지원하고 있다. 하지만 EDISON 플랫폼은 시뮬레이션 서비스에 초점을 맞춰 개발과 서비스를 제공했기 때문에 국내외 MOOC(Massive Open Online Course) 서비스들에 비해 아직 교육 콘텐츠가 부족하다. 그리하여 본 논문에서는 계산과학공학 플랫폼에 교육 콘텐츠를 체계적으로 제공하기 위한 커리큘럼 서비스를 설계 및 제안하였다.

• 대한공업교육학회지
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• v.33 no.2
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• pp.120-136
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• 2008

Using the tangible programming tools, which combines physical objects (e.g. robot) and educational programming language, may help to encourage learners' creative thinking as well as to enhance problem solving ability. That is, learners can have opportunities to simulate problem solving processes through the physical objects, such as robots. Therefore, they can minimize an fixation about problem solving process. These experience is effective to induce creative thinking that is useful to find new solutions and change environment actively. Therefore, we developed a robot based programming teaching and learning curriculum and implemented it in college level introductory programming courses. The result shows that the robot based programming learning has a positive effect in all three factors of learners' creative problem solving potential, especially in a cognitive factor. The cognitive factor includes general problem solving abilities as well as factors that explain creativity, such as divergent thinking, problem recognition, problem representation. These result means that the developed robot based programming teaching and learning curriculum give positive effect to creative problem solving abilities.

• Journal of Information Management
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• v.40 no.1
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• pp.113-132
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• 2009

Unlike existing other industries, the knowledge-based industry has the potential to grow increasingly with factor input unlimited. Importance of investigating knowledge and information evaluation cannot be overemphasized to promote economic development in that knowledge and information is accepted as an engine of new economy. We attempt to define the scope and value of knowledge and information and develop the knowledge and information value model. The results help policy-makers to manage and evaluate the knowledge and information with useful and responsible information.

• Land and Housing Review
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• v.3 no.1
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• pp.69-78
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• 2012

This study proposes an approach to improve the accuracy of land assessment result focused on the Land Suitability Assessment. The detailed analysis processes are; (a) that they are analyzed considering resistance in distance measurement on the space characteristics of location, and; (b) that an assessment result is measured according to the threshold definition of membership function, which is applied in estimating conservation suitability. The assessment results are; firstly, the method considering resistance better reflects the local characteristics of area with worse accessibility including rivers and mountains than one by linear distance; secondly, the existing method that the maximum value of a target area is defined as the maximum threshold may draw a value evaluated lower than a threshold definition considering the distribution of measured indices. Finally, satellite images are overlapped with the assessed results, the applicability level from the approach proposed by this study is more coincident with the present status. The assessment method proposed by this study can be meaningful in view of that it improves the accuracy of Land Suitability Assessment. Furthermore, it can be applied as SDSS, which can support effective establishment of urban policies, in case of complementing the problems in executing the assessment system.

• Journal of KIISE:Information Networking
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• v.33 no.3
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• pp.193-200
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• 2006

The security feature is essential in wireless sensor network such as intrusion detection or obstacle observation. Sensor nodes must have shared secret between nodes to support security such as privacy. Many methods which provide key pre-distribution need too many keys or support poor security. To solve this problem, probabilistic key pre-distribution is proposed. This method needs a few keys and use probabilistic method to share keys. However, this method does not guarantee key sharing between nodes, and neighbor nodes nay not communicate each other. It leads to waste of network resource such as inefficient routing, extra routing protocol. In this paper, we propose new key distribution method using quorum system which needs a few keys and guarantee key sharing between nodes. We also propose extension of the method which needs fewer keys and guarantee key sharing when node deployment knowledge is well known.

• Magazine of the Korea Institute for Structural Maintenance and Inspection
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• v.17 no.1
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• pp.48-59
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• 2013

응력파의 기반한 비파괴 검사법은 비교적 실험 절차 및 실험에 필요한 장비가 단순하고, 인체에 해가 없으며, 비용이 저렴한 특성을 갖고있다. 따라서 건축/토목 구조물의 비파괴 검사에 매우 효과적인 방법으로 알려져 있다. 하지만 기존의 가속도계, 변위계, 지오폰과 같은 부착 센서를 사용할 경우 표면 처리, 센서의 부착 및 이동에 따른 추가적인 시간이 소요되고, 센서와 구조물의 불완전한 커플링으로 인한 측정 결과의 신뢰성 및 일관성을 유지하지 어렵다는 문제를 발생시킨다. 최근 이러한 문제의 해결책으로 Air-coupled sensor (ACS)의 사용이 각광받고 있으며, 여러 연구자들에 의해 ACS의 가능성 및 실용성이 증명되고 있다. 기존의 접촉센서와 비교하여 ACS를 사용했을 때 얻을 수 있는 가장 큰 장점은 센서의 커플링 문제를 근본적으로 해결하여 신뢰도가 높고 일관적인 측정이 가능하고, 대형 건축/토목 구조물의 표면을 음향스캔하여 결과를 신속하게 처리하여 실시간으로 시각화 할 수 있다는 점이다. 이론적으로 ACS를 이용하여 측정하는 물리값은 콘크리트 내부에서 발생된 응력파의 일부가 공기중으로 전파된 누설파 (Leaky wave)이다. 콘크리트 비파괴 검사에 주로 사용하는 100 kHz이하의 저주파를 측정할 경우 일반적으로 콘텐서마이크가 ACS로 사용될 수 있다. 기존 연구자들은 실험 및 이론적 연구를 통하여 응력파에 기반한 비파괴 방법에서 ACS가 기존의 접촉 센서를 대체할 수 있다는 점을 보여주고 있다. 현재 미국에서는 연방 도로청 (FHWA) 및 국가표준기술연구소 (NIST)의 연구비 지원으로 ACS의 실용성을 높이기 위하여 최적화된 음향반사판의 설계를 통한 ACS 의 민감도를 높이기 위한 연구, 다채널 센서 배열 및 데이터 통합을 위한 새로운 알로리즘 개발, 자동화 및 로봇 기술과 융합과 같은 연구가 활발히 진행되고 있다. 멀지 않은 미래에는 ACS를 장착한 무인 로봇이 다양한 종류의 건축/토목 구조물의 건전도를 평가하기 위하여 종횡무진 활약하는 모습을 현실 속에서 볼 수 있을 것이라 기대한다.

• Journal of the Korean Society for information Management
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• v.12 no.2
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• pp.85-101
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• 1995

Conventional indexing sytstems support only full-text indexing method for electronic documents and do not use logical structure of documents in retrieval. Most electronic documents are in different formats depending on various systems. Also, they only indicate physical style of the document without considering any logical structure. Thus, in the effort to standardize the exchange of documents. IS0 developed SGML(Stadard Generalized Markup Language) which contains information about logical structure of the documents. In this paper, to resolve the disadvantages of full-text indexing method and to use standard document format. indexing system for SGML document is designed and implemented. In this system, user can assign indexing domain on elements, thus the logical structure of document is reflected in retrieving information. Various retrieval methods can be implemented by using the structural information of the document. In addition, automatic indexing for SGML Hangul document is supported in this system

• 한국지구물리탐사학회:학술대회논문집
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• 2002.09a
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• pp.139-162
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• 2002

Since weak zones or geological lineaments are likely to be eroded, weak zones may develop beneath rivers, and a careful evaluation of ground condition is important to construct structures passing through a river. Dc resistivity surveys, however, have seldomly applied to the investigation of water-covered area, possibly because of difficulties in data aquisition and interpretation. The data aquisition having high quality may be the most important factor, and is more difficult than that in land survey, due to the water layer overlying the underground structure to be imaged. Through the numerical modeling and the analysis of case histories, we studied the method of resistivity survey at the water-covered area, starting from the characteristics of measured data, via data acquisition method, to the interpretation method. We unfolded our discussion according to the installed locations of electrodes, ie., floating them on the water surface, and installing at the water bottom, since the methods of data acquisition and interpretation vary depending on the electrode location. Through this study, we could confirm that the dc resistivity method can provide the fairly reasonable subsurface images. It was also shown that installing electrodes at the water bottom can give the subsurface image with much higher resolution than floating them on the water surface. Since the data acquired at the water-covered area have much lower sensitivity to the underground structure than those at the land, and can be contaminated by the higher noise, such as streaming potential, it would be very important to select the acquisition method and electrode array being able to provide the higher signal-to-noise ratio data as well as the high resolving power. The method installing electrodes at the water bottom is suitable to the detailed survey because of much higher resolving power, whereas the method floating them, especially streamer dc resistivity survey, is to the reconnaissance survey owing of very high speed of field work.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.45-52
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• 2016

The purpose of this study was to investigate the meaning of conflict experience in cooperative learning activities of pre-service early childhood teachers. The subjects were 85 pre-service early childhood teachers in W university. The data were collected through unstructured interviews and journal writings of the participants. The study results were as follow. First, pre-service early childhood teacher's conflict experiences in cooperative activity are team meeting, fair participation and evaluation, and conflict of the personal relations. Second, pre-service early childhood teacher's conflict resolution experiences in cooperative activity are autonomy of the team meeting time, reflective thinking, sentimental support, recognition of others, and solving problems by the time spending together. Third, the meanings of conflict experience in cooperative activity are formation of felt responsibility, self-growth through consideration of others, reciprocity, and recognition of the meaning of cooperation.