• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.474-486
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• 2010

In this paper, we propose a new method for detection moving object contour using spatial and temporal edge. In general, contour pixels of the moving object are likely present around pixels with high gradient value along the time axis and the spatial axis. Therefore, we can detect the contour of the moving objects by finding pixels which have high gradient value in the time axis and spatial axis. In this paper, we introduce a new computation method, termed as temporal edge, to compute an gradient value along the time axis for any pixel on an image. The temporal edge can be computed using two input gray images at time t and t-2 using the Sobel operator. Temporal edge is utilized to detect a candidate region of the moving object contour and then the detected candidate region is used to extract spatial edge information. The final contour of the moving object is detected using the combination of these two edge information, which are temporal edge and spatial edge, and then the post processing such as a morphological operation and a background edge removing procedure are applied to remove noise regions. The complexity of the proposed method is very low because it dose not use any background scene and high complex operation, therefore it can be applied to real-time applications. Experimental results show that the proposed method outperforms the conventional contour extraction methods in term of processing effort and a ghost effect which is occurred in the case of entropy method.

• Applied Chemistry for Engineering
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• v.9 no.4
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• pp.486-490
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• 1998

Pt/C powder which was used as electrocatalyst in a Phosphoric Acid Fuel Cell(PAFC) was fabricated by colloid method. It was reported that the sulfur from reductant, $Na_2S_2O_4$, worked as a poison against catalyst during long term operation. To remove these sulfurs, we try to treat Pt/C powder by three different methods. First, we tried to remove the sulfur according to temperature and time in $H_2$ atmosphere. As the heat treatment temperature is raised up, the effect of the removal is increased but the electrode performance is decreased because of the growth of Pt particle size. The optimal heat treatment temperature is $400^{\circ}C$, the size of Pt particle is approximately $35{\sim}40{\AA}$ and the electrode performance is $360mA/cm^2$ at 0.7 V. At $400^{\circ}C$, even though the time of heat treatment is extended, size of Pt, amounts of remaining sulfur and electrode performance is almost constant. Secondly, when we removed in a crucible at $900^{\circ}C$ the removal of the sulfur was not better, but the size of Pt particle, approximately $80{\AA}$, was smaller than that of heat treatment in $H_2$ atmosphere at $900^{\circ}C$. Lastly we treated with solvents such as acetone, benzene, and carbon disulfide. It was observed that sulfur components were removed partly by extraction with solvents, the electrode performances were similar each other.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.217-223
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• 2005

The term 'impaction teeth' is used to designate a tooth which remains unerupted in jaw beyond the time at which it should normally be erupted. Most cases of impacted teeth reported in the literature are permanent teeth. The impaction of primary teeth occur rarely whereas impaction of second primary molars is more numerous than all other impactions. Failure of eruption of primary teeth may cause a number of complications, such as interference with development and eruption of successive permanent teeth, malocclusion, cystic change of tooth follicle. The clinican should consider the various treatment option available (a) No treatment and observation, (b) surgical extraction (c) space regainer. Proper treatment plan should be established after thought consideration of impacted tooth and it's relation with successive permanent tooth.

• Journal of dental hygiene science
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• v.5 no.1
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• pp.13-17
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• 2005

This research was conducted in order to collect and arrange an oral health information needed the school oral hygiene as a part of a long term local community oral hygiene development to promote the oral health of the residents in Sung-Nam. After gathering the information of oral hygiene of 12-year old schoolchildren in Sung-Nam, these conclusions are reached: (1) The experience of dental caries in permanent teeth of 12-year old schoolchildren in Sung-Nam was revealed 74.7%, proportion of children with one or more caries in permanent teeth was 36.2%, and DMFT index was 2.75. (2) DT rate was 28.4% in total and regional difference has been revealed. In Sujung-Gu, DT rate was 36,8% and this was nearly as twice as 19.8% in Bundang-Gu. (3) For permanent teeth, fillings requirements for one surface were 26.6%, more that two surfaces were 13.3%. In addition, artificial crown treatment requirements were 1.8%, dental pulp treatment was 5.3%, and extraction requirement was 2.2%. In contrast, holders of pit and fissure sealant were only 27.1%. (4) In Sung-Nam, oral hygiene education campaign for 12-year old schoolchildren needs to be continued. Simultaneously, early stage examination and preventive approaches for decayed teeth such as pit and fissure sealant need to be considered for schoolchildren who have high tendency of dental caries and who are in areas which show high percentage of dental caries occurrence.

• Restorative Dentistry and Endodontics
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• v.26 no.4
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• pp.296-306
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• 2001

The purpose of this study was to observe the effect of dexamethasone and osteogenic protein-1(BMP-7) on bone, cementum and periodontal tissue regeneration. A total of 60 Sprague-Dawley white female mice were selected and beta-APN was used for five days to extract the maxillary first molar a traumatically. After the extraction of the teeth, the mesiobuccal root canal was filled with Caviton$^{\circledR}$. The teeth were etched with citric acid for 1 min and coated with one of four different experimental solutions : DEX(500nM/ml), DEX(1000nM/ml), OP-1(100$\mu\textrm{g}$/ml) and OP-1(500$\mu\textrm{g}$/ml) for three minutes depending on the group. All teeth were then replanted under microscope. All replantation procedures were done within 30 minutes. Teeth that were replanted after 30 minutes of bench dry only was used as positive control. All animals were sacrificed at 3 weeks following replantation and histologic observtion was done. The results were as follows ; 1. Active root resorption rate was decreased by the order of OP-1(500$\mu\textrm{g}$/ml), DEX(1000nM/ml), OP-1(100$\mu\textrm{g}$/ml), and DEX(500nM/ml). There was statistically less root resorption in OP-1 (500$\mu\textrm{g}$/ml) and DEX(1000nM/ml) group(P<0.05). 2. The group with higher concentration of dexamethasone(1000nM/ml) had statistically more bone union compared to positive control group(P<0.05),but there were no significant differences among four experimental groups. 3. OP-1(500$\mu\textrm{g}$/ml) and DEX(1000nM/ml) groups showed less degree of inflammation compared to the OP-1(100$\mu\textrm{g}$/ml). DEX(500nM/ml), and positive control group (P<0.05). In conclusion, the group with higher concentration of OP-1 had the best results on root resorption, bone ankylosis and anti-inflammatory effects compared to the other experimental groups, but a long-term study is also necessary to evaluate the exact pharmacological effects of the drugs in the future.

• Korean Chemical Engineering Research
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• v.45 no.4
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• pp.311-318
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• 2007

Soil contamination in Korea has been accelerated every year. Because of their persistence and cumulative tendency in the environment, soil contaminants have potential long-term environmental and health concerns and it is estimated to cost enormous expense for clean-up. Korea government has legislated the law on conservation of soil environment in mid 1990s, and managed and treated hazardous wastes in contaminated sites as a remediation policy since then. Soil remediation technologies are classified into in-situ/ex-situ or biological/physico-chemical/thermal processes according to applied places or treatment methods, respectively. In Korea, clean-up of polluted sites has been mostly carried out at military areas, railroad-related sites and small-scale oil spilt sites. For these cases, in-situ remediation technologies such as soil vapor extraction (SVE) and bioventing were mainly used. In recent days, an environmental-friendly soil remediation emerged as a new concept - for example, a new soil remediation process using nanotechnology or molecular biological study and an integrated process which can overcome the limitation of individual process. To have better applicability of remediation technologies, comprehensive understandings about the pollutants and soil characteristics and the suitable techniques are required to be investigated. Above all, development of environmental technologies based on the sustainability accompanied by public attention can improve soil environment in Korea.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.25 no.1
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• pp.15-24
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• 2016

It is considered an implant failure when there is esthetic problems in the anterior area although the prosthesis function normally. In 2003, Dr. Kan et al stated that implant bone level is determined by the adjacent teeth. After that many scholars have studied how can achieve the esthetics result on adjacent teeth bone loss cases. In 2012, Dr. Takino published an article in Quintessence. He summarized previous articles and reclassified the defects from class 1 through 4. Class 1 and 2 depicts a situation where there is no bone loss on adjacent teeth. In Class 3 and 4, interproximal bone loss extends to the adjacent tooth. If one side is involved, it is Class 3. If both sides are involved, it is Class 4. The clue for esthetic implant restoration is whether bone loss extends to adjacent tooth or not. If the bone level of adjacent tooth is sound, we can easily achieve the esthetic but the bone level is not sound, the surgery will be complicated and the esthetic result will be unpredictable. So regenerative surgery for adjacent tooth is necessary for long-term maintenance. But the options and process were so complicated, the purpose of this article is to report the method simplify the surgery and gain a similar outcome.

• Clean Technology
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• v.18 no.4
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• pp.426-431
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• 2012

Carbon-rich coal can be utilized as a fuel for direct carbon fuel cell (DCFC). However, left-behind ash after the electrochemical oxidation may hinder the electrochemical reactions. In this study, we produced ash-free coal (AFC) by thermal extraction and then tested it as a fuel for DCFC. DCFC was built based on solid oxide electrolyte and the electrochemical performance of AFC mixed with $K_2CO_3$ was compared with AFC only. Significantly enhanced power density was found by catalytic steam gasification of AFC. However, an increase of the power density by catalytic pyrolysis was negligible. This result indicated that a catalyst activated the steam gasification reactions, producing much more $H_2$ and thus increasing the power density, compared to AFC only. Results of a quantitative analysis showed much improved kinetics in AFC with $K_2CO_3$ in agreement with DCFC results. A secondary phase of potassium on yttria-stabilized zirconia (YSZ) surface was observed after the cell operation. This probably caused poor long-term behavior of AFC with $K_2CO_3$. A thin YSZ (30 ${\mu}m$ thick) was found to be higher in the power density than 0.9 mm of YSZ.

• The KIPS Transactions:PartB
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• v.11B no.2
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• pp.227-232
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• 2004

When we extract a representative term from text for information retrieval system or a special information for information retrieval and text milling system, we often need to solve the anaphora resolution problem. The antecedent decision problem of a pronoun is one of the major issues for anaphora resolution. In this paper, we are suggesting a method of deciding an antecedent of the third personal pronouns, such as “he/she/they” to analyze the contents of documents precisely. Generally, the antecedent of the third personal Pronouns seem to be the subject of the current statement or previous statement, and also it occasionally happens more than twice. Based on these characteristics, we have found rules for deciding an antecedent, by investigating a case of being an antecedent from the personal pronouns, which appears in the current statement and the previous statements. Since the heuristic rule differs on the case of the third personal pronouns, we described it as subjective case, objective case, and possessive case based on the case of the pronouns. We collected 300 sentences that include a pronoun from the newspaper articles on political issues. The result of our experiment shows that the recall and precision ratio on deciding the antecedent of the third personal pronouns are 79.0% and 86.8%, respectively.

• Journal of the Korean Society for information Management
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• v.27 no.4
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• pp.33-47
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• 2010

The growth of IT technology and the popularity of network based information sharing increase the number of digital contents in military area. Thus, there arise issues of finding suitable public information with the growing number of long-term preservation of digital public information. According to the source of raw data and the time of compilation may be variable and there can be existed in many correlations about digital contents. The business service ontology makes knowledge explicit and allows for knowledge sharing among information provider and information consumer for public digital archive engaged in improving the searching ability of digital public information. The business service ontology is at the interface as a bridge between information provider and information consumer. However, according to the difficulty of semantic knowledge extraction for the business process analysis, it is hard to realize the automation of constructing business service ontology for mapping from unformed activities to a unit of business service. To solve the problem, we propose a new business service auto-acquisition method for the first step of constructing a business service ontology based on Enterprise Architecture.