• Journal of Digital Contents Society
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• v.19 no.1
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• pp.199-204
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• 2018

In this paper, we propose a fast collision detection method for interacting with objects in virtual space. First, in the mesh grouping step, the entire space is divided into small spaces of a predetermined size, and the positions and sizes of the smallest basic stereoscopic shapes (cube or sphere) including all of the meshes belonging to each small space are determined. In the collision detection step, it is checked whether a haptic interface point (HIP) is included in a three-dimensional figure representing a group. When a collision with a specific three-dimensional figure is confirmed, searching is performed only for the meshes in the group to find a mesh on which a possible real collision with HIP occurred. The effectiveness of the proposed algorithm is verified by measuring and comparing the computation time of the proposed method with and without the proposed method.

• Journal of Science Education
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• v.41 no.2
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• pp.195-212
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• 2017

Small group learning is an educational approach to allow students to solve the problems and to achieve a common goal. Especially, small group learning in science education is one of the most important educational approaches and effective to ensure understanding of a topic. Small group learning consisting of three students in science education maximize student understanding and learning efficiency. However, It is reported that the effects of small group learning on achievement show different results, corresponding to different grouping methods(homogeneous/heterogeneous). This study investigated the effects of grouping method on difference of ecological niche of photosynthesis concepts. To achieve this, 1107 7th students were composed of homogeneous and heterogeneous groups classified into top, middle, and bottom levels. The photosynthesis units were divided into four categories: the photosynthesizing place, the substances of photosynthesis, required materials for the photosynthesizing, and environmental factors affecting photosynthesis. A questionnaire was composed by selecting concepts having a frequency of 4% or more based on prior studies on the change of the ecological status of photosynthesis. The questionnaire was scored in terms of relativity and understanding on each of the proposed concepts in the four categories. The result of this study is as set forth below. 1) There was an enhancement of learning the concept of science in small group classes consisting of 3 students. 2) To enhance the average upon composing of a group, it is proposed that the group should be formed homogeneously, and to reduce the deviation between the members, it is proposed that the group should be formed heterogeneously. Through this study, it is expected that specific studies verifying the difference or effect on the duplicity of results are conducted based on the composition of groups.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.279-282
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• 1996

The authors have already proposed a method for grouping of inputs of a logical circuit under test (LCUT) by use of M-sequence correlation. We call this method as input grouping (IG) method. In this paper, the authors propose a new method to estimate the faulty part in the circuit by use of IG when some information on the candidate of faulty part can be obtained beforehand. The relationship between IG and fault probabilities of a LCUT, and undetected fault ratios are investigated for various cases. Especially the investigation was made in case where the IG was calculated by use of n correlation functions (I $G_{inp}$). From the theoretical study and simulation results it is shown that the estimation error ratio of fault probabilities and undetected fault ratio of LCUT are sufficiently small even when only a part of correlation functions are used. It is shown that the number of correlation functions which are to be memorized to calculate IG can be considerably reducible from 2$^{n}$ - 1 to n by use of I $G_{inp}$. So this method would be very useful for a fault diagnosis of actual logic circuit.uit.

• Journal of The Korean Association of Information Education
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• v.14 no.3
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• pp.291-300
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• 2010

Group-based learning is known to be an effective means to improve scholastic achievement in online learning. Therefore, there are some previous researches for the group-based learning. A lot of previous researches define factors for grouping from the characteristics of classes, teacher's decision and students' preferences and then generate a group based on the defined factors. However, many algorithms proposed by previous researches depend on a specific class and is not a general approach since there exist several differences in terms of the need of courses, learners, and teachers. Moreover it is hard to find a automatic system for group generation. This paper proposes a grouping system which automatically generate a learner group according to characteristics of various classes. the proposed system automatically generates a learner group by using basic information for a class or additional factors inputted from a user. The proposed system defines a set of rules for learner grouping which enables automatic selection of a learner grouping algorithm tailored to the characteristics of a given class. This rule based approach allows the proposed system to accommodate various learner grouping algorithms for a later use. Also we show the usability of our system by serviceability evaluation.

• Journal of Sasang Constitutional Medicine
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• v.16 no.1
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• pp.44-52
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• 2004

1. Objects of Research This research is purposed to find Dong-mu's thought on Pharmacology, through summarizing sentences related to pharmacology proposed in the chief writings on Sasang Constitutional Medicine. 2. Methods of Research It was researched bibliologically with Dong-mu's chief medical writings such as "Dongyi Suse Bowon Sasang Chobongyun(東醫壽世保元四象草本卷)", "Dong-mu's posthumos work(東武遺藁)", "Dongyi Suse Bowon(東醫壽世保元)". 3. Results and Conclusions 1. The grouping criteria according to the constitution proposed in "Dongyi Suse Bowon Sasang Chobongyun" is 'Spreading Outside' 'Hardening Inside' 'Cooling Organ' 'Warming Inside', but the grouping of medical herbs according to the constitution is yet not accomplished, and medical herbs is comprehended on base of effectiveness as like existing oriental medicine. 2. The grouping criteria according to the constitution proposed in "Dong-mu's posthumos work"is 'Spreading Choking Raising Lowering' and 'Perfume Smell Fluid Taste', and medical herbs is comprehended on base of effectiveness as like "Chobongyun", and the example on mixing of the herb classified according to the constitution is showed. 3. The medical herbs are comprehended on the basis of how to effect on treatment of constitutional disease, and the principle that it's not to mix of the herb classified according to the constitution is proposed in "Dongyi Suse Bowon". 4. The pharmacology of Sasang Constitutional Medicine is accomplished after it is modified many ti mes through clinic experience for a long time. 5. The pharmacology of Sasang Constitutional Medicine in the early period, is to comprehend herbs on the basis of how to complement 'Spreading Gathering Raising Lowering' of 'Small-Organ(偏小之臟)' according 'Qi-Mei(氣味)' and effectiveness, but that in the late period is to comprehend herbs on the basis of how to complement or to control 'Small-Organ(偏小之臟)' and 'Large Organ(偏大之臟)'.

• Journal of the Korean Chemical Society
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• v.47 no.1
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• pp.72-78
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• 2003

In this study, the effects of grouping by extraversion and introversion in POE learning applied to elementary science class on students' achievement, the perception of learning environment and the attitude toward science instruction were investigated. Ninety-five 5th graders were assigned to the control group and the experimental groups, and taught about acid and base for 9 class hours. In the experimental groups, the homogeneous small group was composed of four introverts or four extroverts, and the heterogeneous small group was composed of two introverts and two extroverts. Two-way ANCOVA results revealed that the homogeneous group performed better than the control group in the application subtest of the achievement test. Significant difference in learning difficulty was found between the heterogeneous group and the control group. In the attitude toward science class, significant interaction effect was found between the instruction and the extraversion/introversion.

• Journal of Korea Port Economic Association
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• v.20 no.1
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• pp.141-151
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• 2004

Although the small and medium ports are actually competing with various strategies, the definition and structural understanding of small and medium ports are not known very much. Therefore this study has launched from this fact, and has the objective of obtaining the structural model for increasing shippers' attraction of small and medium ports. The process began by abstracting the components that composed the success factors through recent research, and grouping it by FA(Factor Analysis) method. Also, by using the FSM(Fuzzy Structural Modeling) method to understand the structure of the grouped components, and the structural model for increasing shippers' attraction of small and medium ports was able to obtain as the result. When analyzing the obtained structural model, easiness of shipment, connection to hubport and efficiency of hinterland network came out to be the most important component groups.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.4
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• pp.632-638
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• 2012

ZigBee network, based on PHY, MAC layer provides a specification for a suite of high level communication protocols using small, low-power digital radio based on an IEEE 802.15.4 standard. Meshing is a type of daisy chaining from one device to another. This technique allows the short range of an individual node to be expanded and multiplied, covering a much larger area. Each wireless technology that makes it to market serves a special purpose or function. Zigbee provides short-range connectivity in what is called a personal-area network (PAN). Within ZigBee PAN coordinator as manages an entire ZigBee network, the short range of frequency band was only selected because the technology allows typically less than 100 kbp or ZigBee troubles in retransmission processing and delaying data tranmission works to create unproductive condition of work. This research was proposed the method, based on short range frequency of zigBee nodes enable to long range of remote data transmission with specific algorithm tools.

• The Transactions of the Korea Information Processing Society
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• v.7 no.7
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• pp.2188-2195
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• 2000

This paper deals with the problem of determining small-bands enclosing a given set of points on the sphere. The small-band is a spherical region, whose boundary is composed of two circles, and which does not contain any great circle. It is a kind of domains that is derived from formalizing the local accessibility problems for 3-axis NC machining into sperical containment problems so as to avoid the grouping. It also can be generated in 4- and 5-axis machine. When a set of points U and the size of a great-band are given, the methods for computing a feasible band and all feasible bands enclosing U in O(n) and O(n log n) time have been suggested, respectively. The methods can be applied into the cases of small bands since the solution region may contain holes. In this paper, we concentrate on the method for determining the smallest small-band enclosing U and suggest an O(n long n) time algorithm, where n is the number of points on the sphere.

• The KIPS Transactions:PartC
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• v.13C no.3 s.106
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• pp.339-344
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• 2006

Secure delivery of multicast data can be achieved with the use of a group key for data encryption in mobile ad hoc network (MANET) applications based on the group communication. However, for the support of dynamic group membership, the group key has to be updated for each member joining/leaving and, consequently, a mechanism distributing an updated group key to members is required. The two major categories of the group key distribution mechanisms proposed for wired networks are the naive and the tree-based approaches. The naive approach is based on unicast, so it is not appropriate for large group communication environment. On the other hand, the tree-based approach is scalable in terms of the group size, but requires the reliable multicast mechanism for the group key distribution. In the sense that the reliable multicast mechanism requires a large amount of computing resources from mobile nodes, the tree-based approach is not desirable for the small-sized MANET environment. Therefore, in this paper, we propose a new key distribution protocol, called the proxy-based key management protocol (PROMPT), which is based on the naive approach in the small-sized MANET environment. PROMPT reduces the message overhead of the naive through the first-hop grouping from a source node and the last-hop grouping from proxy nodes using the characteristics of a wireless channel.