• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.1871-1874
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• 2002

최근 인터넷 환경에서 지리 정보 서비스를 제공받으려는 사용자들의 지속적인 증가로 인해 저비용의 여러 개의 단일 노드를 고속의 네트워크로 연결하여 고성능을 제공하는 클러스터 기반의 공간 데이터베이스에 대한 연구가 활발하게 진행되고 있다. 이러한 공간 데이터베이스 클러스터에서 사용자가 요구한 공간 질의를 빠르게 처리하기 위해서는 고비용의 공간 조인 연산을 효율적으로 처리하기 위한 기법이 요구된다. 본 논문에서는 비공유 공간 데이터베이스 클러스터 환경하에서 공간 조인 연산 수행 시 효율적인 병렬 처리를 위한 영역 분할 기법 및 병렬 공간 조인 기법을 제안한다. 기존의 병렬 공간 데이터베이스 시스템에서의 분할 기반 병렬 공간 조인 기법들은 병렬로 수행할 작업 분배 및 할당과 분할 경계선 상에 존재하는 공간 객체들에 대한 중복 조인 연산 및 중복 결과 제거 등의 추가적인 연산을 해야 한다는 문제점들이 있다. 제안된 기법은 공간 릴레이션들을 일정 영역들로 분할하여 비공유 공간 데이터베이스 클러스터의 각 노드에서 중복없이 저장, 관리하도록 하며 분할 영역의 경계선 상에 위치하는 공간 데이터에 대해서만 중복 저장을 허용하여 병렬 공간 조인 연산 시 누락되는 공간 데이터가 없도록 한다. 본 기법은 공간 조인 연산 시 병렬 처리를 위한 별도의 작업 할당 과정을 거치지 않고 각 노드에서 병렬적으로 공간 조인 연산을 수행하며, 분할 경계선 상에 존재하는 공간 객체들은 여과 과정을 거쳐 한번만 공간 조인이 수행되므로 중복 결과들을 제거하기 위한 별도의 연산이 필요없는 특징을 갖는다. Ad Hoc망의 위상변화에 대한 적응성을 높일 수 있도록 한다. SQL Server 2000 그리고 LSF를 이용하였다. 그리고 구현 환경과 구성요소에 대한 수행 화면을 보였다.ool)을 사용하더라도 단순 다중 쓰레드 모델보다 더 많은 수의 클라이언트를 수용할 수 있는 장점이 있다. 이러한 결과를 바탕으로 본 연구팀에서 수행중인 MoIM-Messge서버의 네트워크 모듈로 다중 쓰레드 소켓폴링 모델을 적용하였다.n rate compared with conventional face recognition algorithms. 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이

• Journal of Korean Academy of Nursing
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• v.26 no.1
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• pp.73-93
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• 1996

This study aimed to analyse the test contents of the national examination for the registered nurses (NERN) over 3 years from 1991 to 1993 in Korea. In recent years in Korea, the MCQ(multiple choice question) has been showing to be a highly recognized method for assessing the qualification of registered nurses. Unfortunately, nursing faculties have found NERN had some bad MCQs through having evaluation workshop for Some MCQs often provide so many unwriting clues which become a bias of the results, and some items fell into the category of the lower level of educational taxonomy such as isolated recall a fact or data. Frequently the stems of the questions are ambigous, unclear, disputable, esoterical or trivial. Considering those fallacies of the national examination, it is very critical to review the test items to see whether it is of high quality, is more fair, reliable and objective in depth. Therefore, this study was done to provide data for the improvement of the test contents as well as the teachers's assessment skill. For this study, the ad hoc committee was composed of 16 members, including 5 education board members of Korean Academic Nurses Association and 11 nursing faculty members. This committee had one day panel discussion and filled the checklist for this study. The process of analysing data was held over 10 times during 1992-1994. The analysis focussed on educational taxonomy such as cognitive domain(knowledge), psychmotor domain (skill), affective domain(attitude) and the level of learning such as recall, understanding, problems solving, and learning area of theory and practice, and the learning content categorised by nursing process and disease process. The test analysed using difficulty index and the structure of the test items was analysed. The conclusions and suggestion as follows : 1. In learning area, the average ratio of the theory and practice was 1 : 1.1 which was less than 1 : 2 suggested by Korean National Health Institute, and the ratio was different by the 8 leaning subjects of nursing. 2. In category of the educational taxonomy, the knowledge domain was emphasized mostly（79. 7％）, the skill domain was 14.9％, and the attitude domain was 5.4％ only. 3. In the level of learning, generally, the test items of the level of recall（45.5％） and the understanding（46.3％） were covered almost and the problem solving was 8.1％. 4. In the learning contents, generally, the test items related to nursing process was 67.2％ and that of disease process was 32.8％. However, this proportion was different by the 8 leaning subjects. Even though the nursing diagnosis has been emphasized in nursing curricula recently, the test items of this was identified very few. 5. In the structure of the test item, some were not clear, incorrect grammar, unclear description and some have clues to answer. 6. In the item analysis, the non-acceptable level of the difficulty index (means too easy) was 65.7％, and the acceptable level was 33.9％. Considering the results we would like to suggest the followings, 1. Since the test items of knowledge domain was dominant, the test items of the practice domain and attitude domain should be emphasized more. 2. The regular review and analysis of NERN should be arranged in order to improve the quality of the test items which will give influence to the nursing education positively.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.4
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• pp.363-368
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• 2000

The purposes of the study was to examine changes in thickness and strength of the rat femur after administration of sodium fluoride in the drinking water. 48 female Sprague-Dawley rats were randomly divided into 4 groups, and they were supplied with 0(control), 1, 5 and 50 ppm of fluoride in the drinking water ad libitum for 6 weeks. Rats were killed and both sides of femur were dissected. Bone strength was measured as the stress of failure of femur at the middle point and femoral neck with Instron. Histologic slides were prepared from the femur shaft with routine processing of fixing, demineralizing, embedding and HE staining. Thickness and area of cortical bone and medullary cavity were measured by using Camera Lucida and Image Analyzer. All the collected data were analyzed with one-way ANOVA, Duncan's multiple range test for post-hoc tests and ANCOVA using the SAS 6.12 package at the level of 0.05. Bone strength increased significantly in the animals given 1 and 5 ppm of fluoride in the water, as compared to the control group. There were significant decreases of stress at fracture in 50 ppmF group compared to the 1 and 5 ppmF groups. The similar trends of bone strength at the femoral neck fracture test, but there were no statistical significances. Cortical bone thickness and area of the femur increased in the 1 and 5 ppmF groups compared to the control. However, the thickness of 50 ppmF group also decreased significantly as compared to 1 and 5 ppmF groups. On the other hand, medullary thickness and area increased in all fluoride groups than control group. All of the findings presented support the conclusion that, low fluoride dosage used in water fluoridation could increase the bone strength and might have preventive effect on femur fracture.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.4
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• pp.53-64
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• 2009

Inter-vehicular communication that propagates information without infrastructures has drawn a lot of interest. However, it is difficult to apply conventional ad-hoc routing protocols directly in inter-vehicular communication due to frequent changes in the network topology caused by high mobility of the vehicles. MMFP(Multi-hop MAC Forwarding) is a unicast forwarding protocol that transport packets based on the reachability information instead of path selection or position information. However, delivering public safety messages informing road conditions such as collision, obstacles and fog through inter-vehicular communication requires broadcast rather than unicast since these messages contain information valuable to most drivers within a close proximity. Flooding is one of the simplest methods for multi-hop broadcast, but it suffers from reduced packet delivery-ratio and high transmission delay due to an excessive number of duplicated packets. This paper presents two multi-hop broadcast protocols for inter-vehicular communication that extend the MMFP. UMHB(Unreliable Multi-Hop Broadcast) mitigates the duplicated packets of MMFP by limiting the number of nodes to rebroadcast packets. UMHB, however, still suffers from low delivery ratio. RMHB(Reliable Multi-Hop Broadcast) uses acknowledgement and retransmission in order to improve the reliability of UMHB at the cost of increase in transmission delay, which we show through simulation is within an acceptable range for collision avoidance application.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.5
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• pp.92-100
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• 2001

This study was conducted to evaluate the growth rate of landscape trees produced in containers for three year, and the growth rate of the establishment period during sixth month~twelve months after transplanting. Two types of container such as plastic pot(pot) and fabric growing bag(bag) were adopted to restrict tree roots. Each type of container was divided into seven sub-types. One traditional production method was included as comparison. Two landscape woody plant species (Magnolia denudata, Albizzia julibrissin) were planted in the seven sub-types of container. After one or two growing season in the container, the trees of each container type were transplanted. Half of the trees were transplanted in the mild spring season, and the other half were transplanted in the improper summer season. The data was collected on the diameter of root cellar and the tree height in each year. The research results are as follows; 1. Container production method was lower than the traditional production methods by 1.3 times ~ 2 times in the growth rates. 2. The Geocell bag and Root control bag revealed higher growth rates than pp-woven bag. And pot- in-pot(double pot)system revealed higher growth rates than the ether container pot system in A denudata. There were no differences in the growth rates between container production system in Albizzia julibrissin. 3, The growth rates of improper transplanting trees was high in the \"pot\" type - \"bag\" type - \"control\" in descending order. Especially, the growth rates of \"pot\" type revealed higher than \"control\" by 4 times. 4. From the results of ANOVA and Ad hoc test, the variable of growth factors of each container types in improper transplanting experiment was not significant for a range of 5% or 1% level. And the growth rates of traditional production method was lower than the container production method. 5. There was no differences in growth rate between the containerized and the traditional production system in the case of proper transplanting experiment. The growth rates of diameter of root collar was higher in the \"control\". The growth rates of tree height was higher in the \"bag\" type. Finally, based upon the results of this study, subsequent research on the development of container materials and maintaining methods that focused on the growth rates would be required.aintaining methods that focused on the growth rates would be required.

• KDI Journal of Economic Policy
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• v.36 no.1
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• pp.43-80
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• 2014

This study suggests a model for calculating total benefit rigorously to use the contingent valuation method (CVM) in cost-benefit analysis (CBA). Estimating households' willingness to pay through survey method, the study attempts to demonstrate if a respondent's income and the distance between a respondent's residence and the location of a target facility affect her willingness to pay. The estimation results from a structural model show that income and distance-decay effects exist and that the calculated total benefit varies largely when these effects are ignored. The study emphasizes the effects of income and distance-decay on the total benefit must be carefully considered in using CVM for CBA. Even though the total project cost is precisely estimated, the benefit/cost (B/C) ratio may differ largely when the total benefit is not correctly calculated. Also, an ad hoc model generates significantly different estimates from the utility difference model this study adopted. The difference in estimates suggests that the total benefit has to be estimated by a structural model. Finally, simulations are performed to check the validity of the model as well as to predict consequences when income and distance-decay effects are not properly treated. The results from simulations reveal it is not desirable to ignore those effects considering the perspectives of balanced regional development.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.4
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• pp.29-39
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• 2009

The need for radio spectrum is recently considered as a huge hurdle towards the rapid development of wireless networks. Large parts of the spectrum are allocated to licensed radio services in proprietary way. However, enormous success of the wireless services and technologies in the unlicensed bands has brought new ideas and innovations. In recent years cognitive radio has gained much attention for solving the spectrum scarcity problem. It changes the way spectrum is regulated so that more efficient spectrum utilization is possible. Multi-hop relay technology on the other hand has intensively been studied in the area of ad hoc and peer-to-peer networks. But in cellular network, only recently the integration of multi-hop capability is considered to enhance the performance significantly. Multi-hop relaying can extend the coverage of the cell to provide high data rate service to a greater distance and in the shadowed regions. Very few papers still exist that combine these methods to maximize the spectrum utilization. Thus we propose a network architecture combining these two technologies in a way to maximize the system throughput. We present the throughput capacity equations for the proposed system model considering various system parameters like utilization factor by the primary users and primary users' transmission radius and through extensive numerical simulations we analyze the significance of work.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.127-136
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• 2007

It is easy to install and maintain a mobile multi-hop wireless network due to its self-organizing characteristics. However it has security weakness of the authentication of mobile multi-hop relay stations. Specially, the mobile multi-hop relay network in the IEEE 802.16j has the additional security weakness caused by the requirement of backward compatibility for mobile stations of the conventional IEEE 802.16 system. In this paper, we propose a novel mutual authentication scheme applicable to IEEE 802.16j-based mobile multi-hop relay network architecture. The scheme is able to resolve the initial trust gain problem of a multi-hop node at its entry to the network, the problem of rogue mobile multi-hop node and the problem of hop-by-hop authentication between multi-hop nodes. Effectively, the scheme is a hybrid scheme of the distributed authentication method and the centralized authentication method which have been considered to be deployed in the wireless ad-hoc network and the wireless network connected to wired authentication servers, respectively. Also, we analyze the effectiveness of the proposed hybrid authentication method.

• Proceedings of the Technology Innovation Conference
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• 1998.06a
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• pp.131-163
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• 1998

The interest in the evaluation of government-sponsored research institutes (GRIs) has increased markedly in Korea in 1990s; this is mainly because of the increasing needs 1) to improve the quality of R&D at GRIs, and 2) to reorient the GRIs' strategic position in Korean national innovation systems due to the enhancement of R&D capabilities of private companies and universities during last decade. As a first attempt to diagnose the managerial and strategic issues of GRIs, a Multi-Ministerial Evaluation Committee was established as an ad hoc task force under the Prime Minister's Office in 1991. According to the recommendations of the committee, the Ministry of Science and Technology (MOST) to which most of GRIs were affiliated, made it a rule to evaluate the annual performance of GRIs since 1992. This paper examines the recent experience of MOST's evaluation of Government-sponsored Research Institute in Korea. After several years'efforts of Science & Technology Policy Institute(STEPI) to build prospective evaluation systenL MOST decided to apply two supplementary approaches for the evaluation of GRIs; one is summative annual evaluation and the other is formative 3-year evaluation. The annual evaluation system that is designed as a temporary measure is to monitor and to guide the self-evaluation activities of GRIs. In the process of annual evaluation, MOST tries to minimize its direct involvement, and allows each GRI to develop self-evaluation system that is most appropriate for the unique characteristics of the institute. If there exist urgent issues under scrutiny, however, it can be incorporated and examined by a group of external experts as special issues in the annual evaluation system. The aim of 3-year evaluation is both to examine the past performance of each GRI and to investigate whether the strategic role of each GRI is viable in the future. Its major focus, however, lies not on auditing past performance but on strengthening future strategic position of each GRI. The MOST designates a group of evaluation experts with appropriate knowledge and competence as members of the General Evaluation Committee for one year. With the help of STEPI, a specialized research institute for R&D evaluation, the General Evaluation Committee develops methodology and procedures for the actual evaluation of GRIs. Based on the evaluation reports and recommendations from the General Evaluation Committee, the MOST develops various policy measures for strengthening GRIs.

• Journal of Arbitration Studies
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• v.22 no.3
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• pp.141-163
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• 2012

In Korea, although nearly all maritime arbitration cases are dealt with by the Korean Commercial Arbitration Board (KCAB), the total number of cases that are referred to the KCAB is relatively small compared with the total number of maritime cases that occur in Korea. There may be reasons why maritime arbitration is not utilized more in Korea. However, of the above reasons, the superseding one may be that there is still a lack of confidence in the credibility and foreseeability of maritime arbitration in Korea. To expand the use of maritime arbitration in Korea, it is essential that the base surrounding maritime arbitration be expanded. In addition, it is also necessary that specialists receivetraining in maritime law. In this context, it is strongly recommended that maritime and admiralty law be taught in law schools and be included as a regular subject on the Korean bar exam. Additionally, to promote maritime arbitration, a rule should be introduced allowing for shortened arbitration proceedings in Korea. Although Chapter 8 of the KCAB Arbitration Rules provide for "Expedited Procedure," this process alone is not because the rules for Expedited Procedure generally apply in arbitration cases where both parties have agreed in a separate agreement to follow the procedures provided or in any domestic arbitration valued atless than 100,000,000 Korean won. Therefore, the KCAB Arbitration Rules for Expedited Procedure must be reformed to encompass international arbitrations. Additionally, experts who are experienced in the maritime sector should be elected as arbitrators. Given the factthat a fair number of arbitration cases can be characterized as international, it is important that businesspersons who are very fluent in English be appointed as arbitrators in order to increase the reliability of maritime arbitration in Korea and save costs. Meanwhile, because lawyers and scholars constitute a considerable portion of KCAB arbitrators, commercial persons from relevant industries should be enlisted as arbitrators. Even though there are arguments for the establishment of an independent maritime arbitration board in Korea, establishment of a separate maritime arbitration board will not directly guarantee the prosperity of maritime arbitration in Korea. Instead of instituting a new maritime arbitration board, it is better that a reorganized KCAB modify existing arbitration proceedings to make them faster and more economical if maritime arbitration is to prosper. In this regard, ad-hoc arbitration would be an option for speedy and thrifty maritime arbitration. Finally, to gain the confidence of domestic and foreign parties, we cannot ignore the importance of advertising the specialties and qualifications of the KCAB and its personnel among business entities.