• Journal of KIISE:Software and Applications
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• v.36 no.1
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• pp.70-81
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• 2009

Ontology is an explicit specification of concepts and relationships between concepts in an interest domain. As considered as one of typical knowledge representation methods, ontology is applied to various studies such as information extraction, information integration, information sharing, or knowledge management. In IT based industries, ontology is applied to research on information integration and sharing in order to enhance interoperability between enterprises. In supply chains or logistics, several enterprises participate as business partners to plan movements of goods, and control goods and logistics flows. A number of researches on information integration and sharing for the effective and efficient management of logistics or supply chains have been addressed. In this paper, we address an ontology as a knowledge-base for semantic-based integration of logistics information distributed in the logistics flow. Especially, we focus on developing an ontology that enables to represent and translate semantic meaning of EPC data in the EPC Network applied logistics. We present a scenario for tracing products in logistics in order to show the value of our ontology.

• Korean Journal of Health Education and Promotion
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• v.19 no.3
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• pp.51-72
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• 2002

This research was conducted to understand and analyze the health-related behaviors of middle school students and get fundamental research data essential to provide efficient student guidance and public health service at school. The interview using Youth Risk Behavior Surveillance System(YRBSS). Translation and modification for Korean students of the YRBS. The Korean version of YRBS(Youth Risk Behavior Surveillance System) that translation and modification for Korean students of the YRBS developed by the Centers for Disease Control and Prevention(CDC)was used to assessment to health-related behaviors of youth. The interviewees were 1040 enrolled students at middle school in Daegu metropolitan city. YRBSS monitors six categories of priority health behaviors among youth and young adults behaviors that contribute to unintentional and intentional injuries; tobacco use; alcohol and other drug use, sexual behaviors that contribute to unintended pregnancy and sexually transmitted diseases(STDs)(including human immunodeficiency virus infection); unhealthy dietary behaviors; and physical activity. The result shows that over 30% of students rarely or never used safety belt and almost students were rarely or never wore a bicycle helmet. During the 12 months preceding the survey, 21.9% female students had felt so sad or hopeless almost every day for $\geq$ 2weeks in a row that they stopped doing some usually activities 20.5% of male middle school students have ever tried cigarette smoking. 26.2% of male students and 27.2% do female students had had over one drinks of alcohol during their lifetime(lifetime alcohol use). 47% of male students had had over one drinks of alcohol on $\geq$ 1 of the 30 days preceding the survey(current alcohol use). Over one half of female student were thought they were overweight. These results suggest that some risk behaviors be very prevalent in a korean middle school students and priority health-risk behaviors, which contribute to the leading cause of mortality and morbidity among youth and adult, often are establish during middle school age, extend into adulthood, are interrelated. Among both children and adults, the leading causes of death are closely linked to these behaviors. Among adults, chronic diseases such as cardiovascular disease, cancer, and diabetes are the national leading killers. Practicing healthy behaviors, such as eating low-fat, high-fruit-and-vegetable diets, getting regular physical activity, and refraining from tobacco use, would prevent many premature deaths. Because health-related behaviors are usually established in childhood, positive choices need to be promoted before damaging behaviors are initiated or become ingrained.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12C
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• pp.1167-1176
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• 2009

In This Paper, we introduce an efficient IFFT design technique named for transmitter of OFDM (Orthogonal Frequency Division Multiplexing) system. In OFDM system, a cyclic prefix is inserted in forepart of OFDM symbol to prevent ICI(Inter-channel Interference) and ISI (Inter-symbol Interference). Attaching cyclic prefix causes delay in storing and copying IFFT result. The proposed IFFT removes this delay because its output is cyclic shifted by the length of cyclic prefix. So we can make a complete OFDM symbol by just copying the forepart of IFFT output to the end. In many cases, the length of cyclic prefix is 1/2n of FFT size, and this IFFT does not require additional hardware complexity and it does not cause any performance degradation.

• 한국전산유체공학회:학술대회논문집
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• 2009.11a
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• pp.151-158
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• 2009

To implement the insects' flapping flight for developing flapping MAVs(micro air vehicles), the unsteady flow characteristics of the insects' forward flight is investigated. In this paper, two-dimensional FSI(Fluid-Structure Interaction) simulations are conducted to examine realistic flow features of insects' flapping flight and to examine the flexibility effects of the insect's wing. The unsteady incompressible Navier-Stokes equations with an artificial compressibility method are implemented as the fluid module while the dynamic finite element equations using a direct integration method are employed as the solid module. In order to exchange physical information to each module, the common refinement method is employed as the data transfer method. Also, a simple and efficient dynamic grid deformation technique based on Delaunay graph mapping is used to deform computational grids. Compared to the earlier researches of two-dimensional rigid wing simulations, key physical phenomena and flow patterns such as vortex pairing and vortex staying can still be observed. For example, lift is mainly generated during downstroke motion by high effective angle of attack caused by translation and lagging motion. A large amount of thrust is generated abruptly at the end of upstroke motion. However, the quantitative aspect of flow field is somewhat different. A flexible wing generates more thrust but less lift than a rigid wing. This is because the net force acting on wing surface is split into two directions due to structural flexibility. As a consequence, thrust and propulsive efficiency was enhanced considerably compared to a rigid wing. From these numerical simulations, it is seen that the wing flexibility yields a significant impact on aerodynamic characteristics.

• The Mathematical Education
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• v.37 no.1
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• pp.87-99
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• 1998

Mathematics education is very important in future because mathematics is the basis of every study, for example, natural and social science, etc. Our nation wide curriculum has been revised six times since 1948. In 1992, the sixth revision was enforced and we are using the revised textbook now. This study aims at helping of continuous investigation for educational curriculum and textbook, and aims at efficient teaching by preventing unnecessary repetition and excessive gap in real field by analyzing the articulation of Analytics part in school textbook from elementary to high school. This thesis consists of the followings. 1.Investigation of the principles and natures of articulation along with curriculum course and notice the articulation based on the analysing tools. 2.Importance of learning functions. 3.To get the propriety, formation of 8 judging group and classification of content materials in function chapters by the judges based on the analyzing tools. 4.Analysis of presentation method and terminologies in the first concepts, suggestion teaching method to reduce gap and help of understanding on first concepts in the study of function. As a result 'development' consists of 55.8% of the total and it is higher than 'duplication' and 'gap'. To be specific in periods, between elementary school and middle school 'development' takes 64.5% and this shows an acceptable articulation in the period. While 39.4% of 'gap' in articulation between middle school and high school looks high compared with 'gap' between the previous periods. The item suggested with the 'gap' is the 'definition of function', 'value of function', 'parallel translation', 'exponential and logarithmic function'. It is observed that these materials is suddenly appeared in high school.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5B
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• pp.437-442
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• 2011

As an Internet Engineering Task Force (IETF) Working Group, 6LoWPAN is standardizing the IPv6 packet transfer technology in accordance with IEEE 802.15.4. It has completed two Request for Comments (RFC) documents, one of which, RFC 4944, addresses fragmentation, reassembly, and header compression technologies. In this paper, a communication mechanism is proposed to provide efficient communication between 6LoWPAN and external nodes. In this mechanism, the gateway between 6LoWPAN and external networks serves as the proxy gateway between nodes. The simulation was conducted using QualNet to compare the performance of the proposed mechanism and the existing RFC 4944 method. The comparative analysis of the proposed mechanism and the existing method showed that the proposed method performed better.

• Journal of KIISE
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• v.41 no.10
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• pp.838-846
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• 2014

Three-dimensional (3D) object retrieval from user-drawn sketch queries is one of the important research issues in the areas of pattern recognition and computer graphics for simulation, visualization, and Computer Aided Design. The performance of content-based 3D object retrieval system depends on the availability of effective descriptors and similarity measures for this kind of data. In this paper, we present a sketch-based 3D object retrieval system by extracting a hybrid edge descriptor which is robust against rotation and translation. The experimental results which are based on HTML5 and WebGL show that proposed sketch-based 3D object retrieval method is very efficient to search and order the 3D objects according to user's intention.

• Journal of KIISE:Databases
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• v.33 no.7
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• pp.668-681
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• 2006

Due to its diverse advantages, XML has secured its position as a standard for data representation and exchange in the Internet. As a consequence, there has been much research on efficient storing and query processing of in data. Storing XML data in a relational database system warrants much benefit in data management and query processing; the system provides a strong query processing and data management function and can be applicable to XML data, its function being extended. In this paper, we design and implement a query translator that translates XQuery, a representative XML query language, into SQL:2003 query. SQL:2003, the latest SQL standard used as a substitute for SQL:1999, defines SQL/XML that supports XML. The main contribution of this paper is as follows: First, we look into the supporting features of XML, defined in the SQL:2003 standard, and propose a user-defined function for shortcoming sections. Second, we propose a way to translate XQuery into SQL that observes the latest SQL standard. Third, we describe in detail the design and the implementation of the translator to show its feasibility as a translator.

• Journal of Intelligence and Information Systems
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• v.10 no.2
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• pp.1-13
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• 2004

This paper presents a method for the multilingual product retrieval agent through XML and the semantic networks in e-commerce. Retrieval for products is an important process, since it represents interfaces of the customer contact to the e-commerce. Keyword-based retrieval is efficient as long as the product information is structured and organized. But when the product information is expressed across many online shopping malls, especially when it is expressed in different languages with cultural backgrounds, buyers' product retrieval needs language translation with ambiguities resolved in a specific context. This paper presents a RDF modeling case that resolves semantic problems in the representation of product information and across the boundaries of language domains. With adoption of UNSPSC code system, this paper designs and implements an architecture for the multilingual product retrieval agents. The architecture is based on the central repository model of product catalog management with distributed updating processes. It also includes the perspectives of buyers and suppliers. And the consistency and version management of product information are controlled by UNSPSC code system. The multilingual product names are resolved by semantic networks, thesaurus and ontology dictionary for product names.

• Journal of Computing Science and Engineering
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• v.5 no.3
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• pp.210-222
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• 2011

In this work, we study the problem of privacy-preservation data publishing in moving objects databases. In particular, the trajectory of a mobile user in a plane is no longer a polyline in a two-dimensional space, instead it is a two-dimensional surface of fixed width $2A_{min}$, where $A_{min}$ defines the semi-diameter of the minimum spatial circular extent that must replace the real location of the mobile user on the XY-plane, in the anonymized (kNN) request. The desired anonymity is not achieved and the entire system becomes vulnerable to attackers, since a malicious attacker can observe that during the time, many of the neighbors' ids change, except for a small number of users. Thus, we reinforce the privacy model by clustering the mobile users according to their motion patterns in (u, ${\theta}$) plane, where u and ${\theta}$ define the velocity measure and the motion direction (angle) respectively. In this case, the anonymized (kNN) request looks up neighbors, who belong to the same cluster with the mobile requester in (u, ${\theta}$) space: Thus, we know that the trajectory of the k-anonymous mobile user is within this surface, but we do not know exactly where. We transform the surface's boundary poly-lines to dual points and we focus on the information distortion introduced by this space translation. We develop a set of efficient spatiotemporal access methods and we experimentally measure the impact of information distortion by comparing the performance results of the same spatiotemporal range queries executed on the original database and on the anonymized one.