• 컴퓨터교육학회논문지
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• 제4권1호
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• pp.161-174
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• 2001

본 연구의 목적은 한국과 영국에서의 학교 컴퓨터 교육을 비교 연구하여 효율적인 컴퓨터 교육을 실시하기 위한 방안을 찾아 제시하는 것이다. 연구 결과 첫째 인프라 구축에서 현저한 차이를 보여주고 있으며, 둘째 S/W구입 예산에서 영국은 정상적인 예산이 책정되어있어 교사들이 쉽게 필요 한 것을 구입 할 수 있으나 한국은 아직도 이에 대한 인식이 부족한 상태다. 셋째 영국에서는 정부 학교 교사 학생 학부모가 거의 혼연 일체가 되어 정보 마인드의 확산이 아주 일반화 되어있으나 한국에서는 아직도 정부위주의 일방적 정책이 강조되고있다. 또한 사범대학에서의 전산담당 교사 양성에서 영국은 실제 현장위주의 교육을 강조한 반면 한국은 대학교에서의 교과과정 위주이며 실제 현장 경험은 겨우 총 4주의 교생실습으로 마무리된다. 또한 한국에서는 부족한 전산 교사를 보충하기 위해 정부는 전문 지식을 갖춘 전공자를 충원 배치하기보다는 교과 과정 개편에 따른 잉여 교사를 단기 부전공 연수를 통하여 배치함으로 학생과 선생님 사이에 적지 않은 갈등을 빚고 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제22권4호
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• pp.550-556
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• 2009

This study was designed to evaluate the effects of dietary prebiotic (mannan oligosaccharide = MOS) and probiotic (Saccharomyces cerevisiae = SC) in finishing turkey diets on carcass, cut yield, meat composition and colour. A total of 72 ten-weeksold Big6 male turkey poults were used in the trial. There were eight replicate floor pens per floor with three birds in each. The experiment lasted up to 20 wks of age. The trial was set up as a completely randomized design with 3 dietary treatments. The treatments were: i) negative control (C, no additive); ii) MOS 1 g per kg of diet and iii) SC 1 g per kg of diet (strain SC47, $300{\times}10^{10}$ CFU/kg). Body weight (BW) and feed intake were determined for each of the two week intervals. Twenty-four birds were slaughtered and eviscerated to determine carcass, carcass parts and internal organ weights at 20 wks of age. Meat colour and pH levels were measured 24 h after slaughter. The dietary treatments did not affect BW and average daily gain during the trial (p>0.05). The average daily feed intake and feed conversion ratio of turkey toms fed with MOS were higher than those of control and SC groups during the overall period (p<0.05). The dietary treatments did not affect carcass yield, breast meat, thigh, wing, liver, heart, empty gizzard, intestine, and abdominal fat pad proportions and meat pH, composition and pigmentation (p>0.05). These results suggest that the addition of MOS and SC is not likely to produce any performance or carcass characteristics in finishing turkeys at 10 to 20 wks of age.

• Journal of Biosystems Engineering
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• 제27권4호
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• pp.341-348
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• 2002

Quality evaluation of red ginsengs is determined by outer shape and inner qualities. Especially, the inner qualities are main grading criteria. Currently, red ginsengs are classified into 3-grades; heaven, earth and good. The best heaven grade must not include inner holes and sponge tissues. This study was conducted to develop a red ginseng sorting system using x-ray image processing technique. Because of lens characteristic, gray values of the central region in the x-ray image are higher and gradually decreased towards the edge regions. This difference of gray values gives trouble in segmentation and detection of inner holes in red ginseng image, so preprocessing technique is necessary. The preprocessing was done by subtracting source image from an empty background image. But, simple subtraction was not quite appropriate because of too small contrast between inner holes and sound part. Scaled subtraction images were obtained by multiplying all gray values by some numbers. However this method could not help to set threshold value because the gray values of root part are generally lower than body part when red ginseng is exposed to the x-ray. To determine threshold value for detecting inner holes, an algorithm was developed by increasing overall gray values of less clear images.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권9호
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• pp.2442-2454
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• 2012

To ensure the security of wireless sensor networks, it is important to have a robust key management scheme. In this paper, we propose a Quorum-based key management scheme. A specific sensor, called as key distribution server (KDS), generates a key matrix and establishes a quorum system from the key matrix. The quorum system is a set system of subsets that the intersection of any two subsets is non-empty. In our scheme, each sensor is assigned a subset of the quorum system as its pre-distributed keys. Whenever any two sensors need a shared key, they exchange their IDs, and then each sensor by itself finds a common key from its assigned subset. A shared key is then generated by the two sensors individually based on the common key. By our scheme, no key is needed to be refreshed as a sensor leaves the network. Upon a sensor joining the network, the KDS broadcasts a message containing the joining sensor ID. After receiving the broadcast message, each sensor updates the key which is in common with the new joining one. Only XOR and hash operations are required to be executed during key update process, and each sensor needs to update one key only. Furthermore, if multiple sensors would like to have a secure group communication, the KDS broadcasts a message containing the partial information of a group key, and then each sensor in the group by itself is able to restore the group key by using the secret sharing technique without cooperating with other sensors in the group.

• 대한수학교육학회지:수학교육학연구
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• 제25권1호
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• pp.1-19
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• 2015

이 글은 국가수준 학업성취도 평가에 출제된 선다형 문항을 분석하여 교육과정이나 교수 학습, 평가에 개선할 여지가 있는지를 탐색하는 것에 목적을 두고 있다. 이를 위해 답지 반응률 분포 그래프를 이용하여 문항 전체뿐만 아니라 특정 답지가 담고 있는 내용에 대하여 학생들이 어떠한 특성을 보이는지를 분석할 것이다. 이러한 분석은 전체 집단의 평균 정답률과 변별도, 부분 집단별 평균 답지 반응률과 같은 기술통계치보다 많은 정보를 제공해 준다. 왜냐하면 학생들의 능력에 따른 반응의 변화가 잘 드러나기 때문이다. 이러한 방식의 문항 분석으로부터 소인수 개념이나 소인수분해, 속도와 같은 비, 일차함수의 개념, 원뿔의 부피, 입체도형의 성질, 공사건과 전사건의 확률 등에 대해서 시사점을 얻고 있다.

• 한국통신학회논문지
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• 제30권5C호
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• pp.382-390
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• 2005

허프만 코드는 영상이나 비디오 전송뿐만 아니라 여러 분야에서 광범위하게 사용되고 있는 데이터 압축 알고리즘으로서, 실시간 데이터의 양이 증가함에 따라 효율적인 디코딩 알고리즘에 관한 많은 연구가 진행되고 있다. 본 논문에서는 호프만 디코딩을 위해 균형 트리를 형성하여 효율적인 이진 검색을 수행하는 구조를 제안하고 타 구조와의 성능을 비교하였다. 제안하는 구조는 길이가 다른 코드워드 간의 크기 비교를 가능하게 하는 정의를 사용하여 비어있는 내부 노드를 포함하지 않는 완전 균형 트리를 구성하므로, 디코딩 테이블을 위해 필요로 하는 메모리의 크기에 있어 매우 우수한 구조이다. 실제 영상 데이터를 사용하여 실험한 결과, 256개의 심볼 set에 대해 제안하는 구조는 매우 적은 수의 테이블 엔트리를 요구하며, 디코딩 성능은 최소 1번, 최대 5번, 평균 2.41번의 메모리 접근을 소요함을 보았다.

• 건축역사연구
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• 제14권4호
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• pp.7-28
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• 2005

We are so used to the concept of the term 'space' that we do not question its conceptual validity. However, this paper argues that the notion of space prevailing all over the world, is not a universal concept that can be applicable to all architectures of the world, but is a particular concept that is generated from the Western way of thinking. This paper alms to identify the conceptual structure of the idea of space as it is originated in the tradition of the West, and, as an alternative view of space, tries to identify the nature of the view of space perceived in the tradition of the Eastern architecture. Comparison of the two views, that of the East and the West, and their meaning in the future of architecture, is another task to discuss in this paper. To be able to clarify the meaning of space in East Asian tradition, a set of new perspective of understanding of space was invited. They are ; 1. sky-earth(天地); insisting that the notion of space should be replaced within the context of sky, which is one half of sky-earth totality 2. energy of the air (空氣), space is not empty part inside of a building, but is a dynamic condition of air that is a part of the sky which always exist in form of energy 3. place(자리): instead of space, which, basically. is a man-made concept, idea of place is necessary, which include not only space but also earth Such concept of space which is different from the notion of space of the West, is meaningful not only to identify the idea of space in the East, but also to be able to contribute for more dynamic, varied, and balanced understanding of space.

• Restorative Dentistry and Endodontics
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• 제45권3호
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• pp.33.1-33.10
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• 2020

Objectives: This study was conducted to evaluate the effects of traditional and contracted endodontic cavity (TEC and CEC) preparation with the use of Reciproc Blue (RPC B) and One Curve (OC) single-file systems on the amount of apical debris extrusion in mandibular first molar root canals. Materials and Methods: Eighty extracted mandibular first molar teeth were randomly assigned to 4 groups (n = 20) according to the endodontic access cavity shape and the single file system used for root canal preparation (reciprocating motion with the RCP B and rotary motion with the OC): TEC-RPC B, TEC-OC, CEC-RPC B, and CEC-OC. The apically extruded debris during preparation was collected in Eppendorf tubes. The amount of extruded debris was quantified by subtracting the weight of the empty tubes from the weight of the Eppendorf tubes containing the debris. Data were analyzed using 1-way analysis of variance with the Tukey post hoc test. The level of significance was set at p < 0.05. Results: The CEC-RPC B group showed more apical debris extrusion than the TEC-OC and CEC-OC groups (p < 0.05). There were no statistically significant differences in the amount of apical debris extrusion among the TEC-OC, CEC-OC, and TEC-RPC B groups. Conclusions: RPC B caused more apical debris extrusion in the CEC groups than did the OC single-file system. Therefore, it is suggested that the RPC B file should be used carefully in teeth with a CEC.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.627-629
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• 2017

평면 상에 주어진 n개의 직사각형에 대한 합집합과 교집합을 구하는 문제에 대해 많은 연구 결과가 나와 있다. Lipski와 Preparata(1981)는 좌표축에 평행한 직사각형의 합집합을 구하는 문제에 대해서 O(nlogn) 시간과 O(nlogn) 공간의 순차 알고리즘을 제시하였고[1], Alevizos(2013)는 이를 개선한 O(nlogn) 시간과 O(n) 공간의 개선된 순차 알고리즘을 제시하였다[2]. 본 논문에서는 좌표축에 평행한 직사각형들의 교집합이 공집합이 아닌 경우에 대한 직사각형들의 합집합을 구하는 문제를 고려한다. 이 경우, 직사각형들의 합집합은 하나의 연결된 영역, 즉 직교다각형이 된다. 본 논문에서는 재구성가능한 메쉬(RMESH) 모델에서 상수 시간에 이 문제를 해결하는 병렬 알고리즘을 제시한다.

• 한국환경과학회지
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• 제20권7호
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• pp.857-872
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• 2011

The variation of groundwater level in Jeju Island is analyzed with the data of precipitation observed from 48 monitoring post and groundwater level observed from 84 monitoring wells during 2001 to 2009. The groundwater level rises in summer and falls in winter. The rise of groundwater level by precipitation is fast and small in the eastern region and slow and large in the western region. However, the speed of fall during the period of no rain is slower in the eastern region than in the western region. It tells that permeability is greater in the eastern region than in the western region. In this paper, we set up the base level of groundwater and calculate recharge volume between the base level and groundwater surface. During the period, the average recharge volume was $9.83{\times}10^9m^3$ and the maximum recharge volume was $2.667{\times}10^{10}m^3$ after the typhoon Nari. With these volume and the recharge masses obtained by applying the recharge ratio of 46.1%, estimated by Jeju Province (2003), the porous ratio over the whole Jeju Island is 16.8% in average and 4.6% in the case of maximum recharge volume just after typhoon Nari. A large difference in the two ratios is because that it takes time for groundwater permeated through the ground just after rain fall to fill up the empty porous part. Although the porous ratios over the whole Jeju Island obtained in this way has a large error, they give us the advantage to roughly estimate the amount of recharged groundwater mass directly from observing the groundwater level.