• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.6
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• pp.588-593
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• 2006

Cyst is pathologic disease develops in hard tissue as well as soft tissue, which is lined by epithelium filled with liquid, semi-liquid, or air. Origins and symptoms of the cyst are various according to region, and symptoms are malocclusion, diversion of root, tooth mobility, periapical swelling, discoloration and lesion expansion, because the odontogenic cysts begin in the numerous rests of odontogenic epithelium. But almost cysts produce no symptoms unless secondary infection occurs. Treatment of small cysts may include extraction, endodontic therapy, and apical surgery. Treatment of a large cysts usually involves surgical removal (enucleation), Marsupialization(a method of decompression) or combination of two before mentioned. Bone graft is done for helping of bone defect healing at the same time of enucleation This clinical research from January 2000 to December 2005, analyzed by the age, sex, classification, size, region, treatment method, whether or not of bone graft of cyst in the jaw in Daegu Catholic University Hospital.

• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.1-8
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• 1998

A Hardware system of hybrid environmental control was developed for using it in the multi-greenhouse. Now, an on/off control system is most utilized in protected cultivation, but a hybrid environmental control system is not yet. This system consists of a hardware to be devided by physical elements and a software for the hardware a personal computer, a hybrid environmental control and a communication Program for modules. The hardware was made of several independent modules with independent CPU. Each module was made to slots. which are very convenient to mount and take off. Also, they are managed easily to repair, add, remove, and change of their function and expansion. The software for a personal computer was a menu driven program written in visual basic within a Windows environment for easy applications by a user. The hybrid environmental control software have operating factors operate continuously with temperature, humidity and others in greenhouse. Communication programs were used both 485 communication method for long distance communication between modules and CRC communication method for making easy to program, and less errors between personal computer and modules.

• Korean Institute of Interior Design Journal
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• v.22 no.1
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• pp.231-238
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• 2013

As the technical medium evolves, the method of accepting information is changing. The technical medium also appears in various ways through the combination with art. This study aims to conduct research on how hypermedia, appearing from this, will reveal itself in the urban public design in terms of its expression mode. First, this study looks at the characteristics for expression representation of hypermedia art through theoretical considerations on the hypermedia. Second, this study identifies how hypermedia art is introduced in the urban public design through art cases. Third, this study reveals the characteristics depending on the expression mode of hypermedia art shown in the urban public design based on the analyzed cases. As a result, first, hypermedia appeared in various image lighting expression modes that use 'light' in the urban public design and interacted with the public. Second, hypermedia reacted to 'motion' and was the expression mode of using bodies in the urban public design and using peripheral devices and external environment and characterized by having complex patterns of multi-layered structure through multi-media. It also applied sight, hearing, and touch partially or integratedly to attract synesthesia from the public and checked mutual interaction rapidly in an improvised way. Third, such a complex digital technology was the network expression mode beyond space and time by medium of urban public design and characterized by the new experience of virtual space expansion through the world wide network and the communication mode of participation. With such a role change of media and combination with art, hypermedia has been achieving varied extended representations. It is considered to change our monotonous urban environment, restore our relationship with the public, and open a new field of communication. Accordingly, the significance of this study can be identified through how it aimed to display the expression method of hypermedia which caused its extension in the field of urban public design as well as through the derivation of relevant characteristics.

• The KIPS Transactions:PartB
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• v.16B no.3
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• pp.247-256
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• 2009

Typical pseudo-relevance feedback methods assume the top-retrieved documents are relevant and use these pseudo-relevant documents to expand terms. The initial retrieval set can, however, contain a great deal of noise. In this paper, we present a cluster-based resampling method to select better pseudo-relevant documents based on the relevance model. The main idea is to use document clusters to find dominant documents for the initial retrieval set, and to repeatedly feed the documents to emphasize the core topics of a query. Experimental results on large-scale web TREC collections show significant improvements over the relevance model. For justification of the resampling approach, we examine relevance density of feedback documents. The resampling approach shows higher relevance density than the baseline relevance model on all collections, resulting in better retrieval accuracy in pseudo-relevance feedback. This result indicates that the proposed method is effective for pseudo-relevance feedback.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.13 no.2
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• pp.89-99
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• 2001

In the present paper, Helmholtz resonator, which is widely used as a sound-amplification device, is applied to the development of seawater-exchanging breakwater. The incident waves can induce a large response in the resonator when incident wave frequency is close to one of natural modes of the resonator. Largely amplified potential energy due to the resonance supplies clean seawater into the harbor side throughout the channel. Flow supplied by the resonator circulates the seawater of harbor and helps to improve water quality. Within the framework of linear potential theory, matched asymptotic expansion method is employed to analyze the wave responses in a resonator. The semi-circular shape of the resonator has been chosen as an analytic model for mathematical simplicity. The wave responses of both single and arrays of Helmholtz resonator are investi¬gated. To validate an analytic solution, model test is conducted at 2-dimensional wave tanle Wave hcights in the resonator and velocity at the channel are measured for the state of valve-on and valve-off.

• Journal of the Korean Society for information Management
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• v.20 no.4 s.50
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• pp.23-48
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• 2003

In this study an information filtering system was implemented and a series of relevance feedback experiments were conducted using the system. For the relevance feedback, the original queries were searched against the database and the results were reviewed by the researchers. Based on users' online relevance judgements a pair of 17 refined queries were generated using two methods called 'co-occurrence exclusion method' and 'lower frequencies exclusion method,' In order to generate them, the original queries, the descriptors and category codes appeared in either relevant or irrelevant document sets were applied as elements. Users' relevance judgments on the search results of the refined queries were compared and analyzed against those of the original queries.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.2
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• pp.156-165
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• 2014

This paper is the first investigation on the effect of flow control methods on the part load performance in a spark ignition engine. For comparison of the methods, two control devices, port throttling and masking, were applied to a conventional engine without any design change of the intake port. Steady flow evaluation shows that steady flow rates per unit opening area and swirl ratio are very low compared with the port throttling and saturated from mid-stage valve lift, however, swirl increases slightly as the lift is higher in case of 1/4 masking control. In the part load performance, the effect of simple port throttling on lean misfire limit expansion is limited and insufficient; on the other hand a masking improves the limit considerably without any port modification for increasing swirl. Also the results show that the intake flow control improves the combustion with following two mechanisms: stratification induced by the combination of the flow pattern and the fuel injection timing attribute to ignition ability and the intensified flow ensure fast burn. In addition fuel consumption reduces under the flow controls and the reduction rate is different according to the operation conditions and control methods. At the Stoichiometric and/or low speed and low load the throttling method is more advantageous; however vice versa at lean and high load condition. Finally, the throttling is more efficient for HC reduction than masking, on the other side the NOx emissions increase under the masking and decrease under the port throttling compared with conventional port scheme.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.5
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• pp.22-28
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• 2008

This paper aims to offer a solution based on semantic document classification to improve e-Government utilization and efficiency for people using their own information retrieval system and linguistic expression. Generally, semantic document classification method is an approach that classifies documents based on the diverse relationships between keywords in a document without fully describing hierarchial concepts between keywords. Our approach considers the deep meanings within the context of the document and radically enhances the information retrieval performance. Concept Weight Document Classification(CoWDC) method, which goes beyond using existing keyword and simple thesaurus/ontology methods by fully considering the concept hierarchy of various concepts is proposed, experimented, and evaluated. With the recognition that in order to verify the superiority of the semantic retrieval technology through test results of the CoWDC and efficiently integrate it into the e-Government, creation of a thesaurus, management of the operating system, expansion of the knowledge base and improvements in search service and accuracy at the national level were needed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.2
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• pp.183-191
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• 2006

The accuracy of the upward continuation is assessed through the gravity modeling using an ultra-high degree spherical harmonic expansion. The difficulties in the numerical calculation of Legendre function with ultra-high degree, underflow and/or overflow, is successfully resolved in 128 bit calculation scheme. Using the generated Legendre function, the gravity anomaly with spatial resolution of $1'{\times}1'$ on the geoid is calculated. The generated gravity anomaly is degraded and extracted with various noise levels and data intervals, then upward continuation is applied to each data sets. The comparison between the upward continued gravity disturbances and the directly calculated from the spherical harmonics showed that the accuracy on the direct method was significantly better than that of Poisson method. In addition, it is verified that the denser and less noised gravity data on the geoid generates better gravity disturbance vectors at an altitude. Especially, it is found that the gravity noise level less than 5mGal, and the data interval less than 2arcmin is necessary for next generation precision INS navigation which requires the accuracy of 5mGal or better at an altitude.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.1-10
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• 2013

Major issues in water supply service have changed from expansion of service area to improvement of service quality, i.e., water quality and safety, and early response to emergency situation. This change in the service concept triggers the perceptions of limitation with the current centralized water supply system and of necessities of decentralized (distributed) water supply system (DWSS), which can make up the limitations. DWSS can reduce the possibility of water supply outage by establishing multiple barriers such as emergency water supply system, and secure better water quality by locating treatment facilities neighboring consumers. On the other hand, fluctuation of water demand will be increased due to the reduced supply area, which makes difficult to promptly respond the fluctuating demand. In order to supplement this, hybrid water supply system was proposed, which combined DWSS with conventional water supply system using distributing reservoir to secure the stability of water supply. The Optimal connection point of DWSS to existing water supply network in urban area was determined by simulating a supply network using EPANET. Optimal location of decentralized water treatment plant (or connection point) is a nodal point where changes in pressure at other nodal points can be minimized. At the same time, the optimal point should be selected to minimize hydraulic retention time in supply network (water age) to secure proper water quality. In order to locate the point where these two criteria are satisfied optimally, Distance measure method, one of multi-criteria decision making was employed to integrate the two results having different dimensions. This methodology can be used as an efficient decision-support criterion for the location of treatment plant in decentralized water supply system.