• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.2
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• pp.122-131
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• 2010

This paper introduces the concept of a virtual ecosystem and reports the following three mathematical approaches that could be widely used to construct such an ecosystem, along with examples: (1) a molecular dynamics simulation approach for animal flocking behavior, (2) a stochastic lattice model approach for termite colony behavior, and (3) a rule-based cellular automata approach for biofilm growth. The ecosystem considered in this study consists of artificial organisms and their environment. Each organism in the ecosystem is an agent that interacts autonomously with the dynamic environment, including the other organisms within it. The three types of model were successful to account for each corresponding ecosystem. In order to accurately mimic a natural ecosystem, a virtual ecosystem needs to take many ecological variables into account. However, doing so is likely to introduce excess complexity and nonlinearity in the analysis of the virtual ecosystem's dynamics. Nonetheless, the development of a virtual ecosystem is important, because it can provide possible explanations for various phenomena such as environmental disturbances and disasters, and can also give insights into ecological functions from an individual to a community level from a synthetic viewpoint. As an example of how lower and higher levels in an ecosystem can be connected, this paper also briefly discusses the application of the second model to the simulation of a termite ecosystem and the influence of climate change on the termite ecosystem.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.2
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• pp.291-305
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• 1996

The purpose of this study was to investigate the distribution of nerves in the dental pulp of early extracted primary teeth, normal exfoliated primary teeth, partially-erupted, nonfunctional, premolars, and erupted, functional, premolars. Numbers of sample were 10 teeth in each group. The distribution of nerves in the dental pulp were investigated by means of immunohisto chemistry for detection of neurofilament protein(NFP). The results were as follows: The early extracted primary teeth exhibited patterns of innervation similar to those observed for young permanent teeth. The plexiform arrangement of fibers was not evident in the primary teeth. Most nerves appear to terminate about the odontoblasts. As primary teeth began to undergo root resorption, degenerative changes such as vesicles and fragmentation appear in the nerves. The quantity of neural tissue also decreased. In teeth in which the roots were almost completely resorbed only a small number of nerves remain. There was a decrease in the number of terminal branches in the pulp of the partially erupted, nonfunctional, premolars and those present reached the pulpo-odontoblastic border. The nerve terminals in the pulp of the erupted, functional, premolars were traced to the dentinal tubule and a few nerve fibers formed loops in the predentin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.1
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• pp.97-102
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• 2008

For the use of salmon frame in zero emission, the snack using residues of salmon Gomtang was prepared and investigated on the food component characterization. According to the results of volatile basic nitrogen, water activity and sensory evaluation, the optimal substitution ratio of residues was 15% based on the mix. Total amino acid content was higher in the snack (14.8 g/100 g) with 15% residues than in snack (9.8 g/100 g) without residues. The major amino acids of the residues-added snack were aspartic acid (9.9%), glutamic acid (14.7%) and proline (9.5%). The snack with 15% residues were enriched in the mineral (calcium and phosphorus) and polyunsaturated fatty acid (20:5n-3 and 22:6n-3) compared to those of snack without residues.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.126-134
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• 2015

A sleep disorder is being recognized as one of the major health issues related to high levels of stress. At the same time, interests about quality of sleep are rapidly increasing. However, diagnosing sleep disorder is not a simple task because patients should undergo polysomnography test, which requires a long time and high cost. To solve this problem, an accelerometer embedded wrist-worn device is being considered as a simple and low cost solution. However, conventional methods determine a state of user to "sleep" or "wake" according to whether values of individual section's accelerometer data exceed a certain threshold or not. As a result, a high miss-classification rate is observed due to user's intermittent movements while sleeping and tiny movements while awake. In this paper, we propose a novel method that resolves the above problems by employing a dynamic classifier which evaluates a similarity between the neighboring data scores obtained from SVM classifier. A performance of the proposed method is evaluated using 50 data sets and its superiority is verified by achieving 88.9% accuracy, 88.9% sensitivity, and 88.5% specificity.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.660-666
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• 2003

The purpose of this study was to investigate the inhibitory effect of Er:YAG laser against the intraoral acid producing bacterium of S. mutans. Bacterial pellet containing S. mutans KCTC 3065 was irradiated by Er:YAG laser having a $650\;{\mu}m$ diameter beam by non-contact mode. Irradiated parameters were 50mJ, 10Hz and exposure time were 1s, 3s, 5s, 7s, 9s respectively. We obtained the following results of relative growth rate and acid-producing ability of S. mutans by culturing for 48hrs. 1. The growth rate of S. mutans was decreased in the group of laser irradiation compared to the control group(P<0.01). 2. The growth rate at laser irradiation group of 7s, 9s irradiation time was decreased significantly compared to the laser irradiation group of 1s, 3s, 5s irradiation time, until 12 hours(P<0.05). After 24 hours, all groups of laser irradiation were not found to be statistically different in each other. 3. The acid-producing ability of S. mutans was inhibited for a certain duration by irradiation of laser. In summary, the growth rate and acid producing ability of S. mutans decreased according to laser irradiation. This effect was directly related to the amount of irradiation time. These results suggested that Er:YAG laser had an growth inhibition effect on S. mutans.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.63.4-64
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• 2016

본 발표에서는 DSLR 카메라와 CCD를 이용하여 과학고등학교의 R&E교육과정에서 수행한 몇 가지 실험과 그 결과를 소개한다. DSLR 카메라와 SQM을 이용한 밤하늘 특성 분석, CCD를 이용한 고유운동 측정, DSLR을 이용한 산개성단의 측광, CCD를 이용한 산개성단의 측광과 이를 통한 산개성단의 질량분리와 역학적 진화에 대한 연구이다. 실험은 부산일과학고, 울산과학고, 부산과학고에서 수행되었으며, 모든 실험의 결과는 학생들이 직접 관측한 결과를 바탕으로 이루어졌다. 본 실험의 방법과 과정은 일선 학교에서 응용하여 활용될 수 있으며, 실험의 결과는 향후 유사한 실험 교육을 수행할 때 기초 자료로 활용되어 질 수 있다.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.1
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• pp.107-114
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• 2002

The purpose of this study was to determine and compare the shear bond strength of two self-etching primer systems to primary teeth contaminated with saliva and blood. Clearfil SE Bond and AQ Bond were evaluated. One hundred specimens were made by seventy-five deciduous teeth(fifty anterior and twenty-five posterior teeth) and divided randomly into ten groups. Small flat dentinal surfaces were prepared by grinding the buccal, lingual and labial areas. Specific surface treatments were applied to each group: (1) a self-etching primer application(control group), (2) saliva contamination followed by primer(Group I), (3) primer curing followed by saliva contamination (Group II), (4) blood contamination followed by primer(Group III), (5) primer curing followed by blood contamination(Group IV). After bonding of composite resin(Z100, 3M, USA) to contaminated sample surfaces and thermocycling(1,000 cycles), shear bond strengths were measured using Universal Testing Machine(Zwick Z020, Zwick Co., Germany). The results were as follows; 1. Group I showed lower shear bond strength than control group but no statistically significant difference was found(P>0.05). 2. Group II and blood contamination group(Group III & IV) showed significantly lower shear bond strength than control group(P<0.01). 3. The shear bond strength of Clearfil SE Bond was significantly higher than that of AQ Bond(P<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.371-375
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• 2002

The calcifying odontogenic cyst(COC) showed diverse terminology or classification, clinicopathologic features as well as in its biologic behavior, although it was recognized as a distinct clinicopathologic entity. The epithelial lining of a COC appears to have the ability to induce the formation of dental tissues in the adjacent connective tissue wall, and that other odontogenic tumors may sometimes be associated with it. This case is a COC associated with a complex odontoma involving an impacted left maxillary lateral incisor in a 5-year-old female child. Radiographic examination revealed a well-demarcated radiolucent lesion partially occupied by a radiopaque mass, involving the left lateral incisor crown. The histologic sections showed a cystic cavity lined with ameloblastic epithelium containing ghost cell masses with admixed with complex odontoma components. The presence of mixed radiolucent-radiopaque lesion in children as observed in this case, the possibility of COC must be considered. In this case, there was no recurrence 1 year after enucleation and the space control is ongoing now.

• Journal of the Korean Geotechnical Society
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• v.30 no.3
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• pp.47-58
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• 2014

To investigate the unsaturated characteristics of the tailings obtained from the waste dump at Imgi mine, matric suction and volumetric water content were measured in both drying and wetting processes using Automated Soil-Water Characteristics Curve Apparatus. Based on the measured result, Soil Water Characteristic Curves (SWCC) were estimated by van Genuchten model. According to the unsaturated soil classification method, the tailings of the waste dump correspond to clayey sand. As a result of Suction Stress Characteristic Curve (SSCC) by Lu and Likos model, SSCC has a shape of S which is similar to SWCC. The hysteresis phenomenon occurred in SSCCs, which means the suction stress of drying path is larger than that of wetting path in the same effective degree of saturation. The effective stress of unsaturated soil is equal to that of saturated soil when matric suction is less than Air Entry Value (AEV). However, the effective stress of unsaturated soil is larger than that of saturated soil when matic suction is more than AEV. Meanwhile, unsaturated hydraulic conductivity by van Genuchten model decreased with increasing matric suction, and the hydraulic conductivity of drying path is larger than that of wetting path.

• Korean Journal of Environment and Ecology
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• v.17 no.3
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• pp.258-267
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• 2003

The purpose of this study is to present improvement devices of urban center's green function in the Public Open Space Attached Building(P.O.S.) in Incheon, Korea. Study sites were the P.O.S. of office building(10 place), transportation facility building(3 places), government office building(2 places) that were made up 1994∼2002 and analyzed establishment, using and planting status. And P.O.S.'s planting area structure of Osaka and Kawasaki in Japan that is operating P.O.S. system similar to Korea was compared with study sites of Incheon. P.O.S. of Incheon is not managing as valuable urban center's green and establishing to satisfy legal requirement. The strengthening devices of P.O.S. function are as follows. First, it is desirable that planting area rate of P.O.S. in order to develop small park in urban center is increasing by 40% that is children's park level. Second, it must be conferred about planting basis, tree selection and planting method etc. of P.O.S. with green and park development department at building authorization. Third, by the 'landscape planting standard of plottage' that is becoming planting standard of P.O.S is heightened and must increase quality and amount of green. Fourth, it is required mandatory establishing of sign so that citizens can search easily and utilize of P.O.S. Fifth, legal regulation should be decided to prevent that P.O.S. is used unlike purpose originally.