• Journal of dental hygiene science
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• v.15 no.2
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• pp.159-165
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• 2015

A self-administered survey was conducted on the dental hygiene students at three different colleges located in Gyeonggi Province and South Chungcheong Province respectively from October, 2013, to the same month of 2014 to grasp their oral health management behavior, differences in plaque index according to plaque index systems and the correlation of the two. And their plaque index was measured. The findings of the study were as follows: 62.8% of the respondents replied they got a dental checkup over the past year, and 84.1% answered they received preventive dental treatment once at least or more. 80.5% replied they used a fluorine-containing dentifrice. 90.9% answered they used the rolling method to brush their teeth, and 50.0% replied it took three minutes to brush their teeth. They got a mean of 27.88 when O'leary index was used among plaque index systems. Their PHP index and PHP-M index were respectively a mean of 1.30 and a mean of 12.12. Their plaque index became lower when they spent more time brushing their teeth, and the toothbrushing time made a statistically significant difference to that (p<0.05). The factor that exerted the largest influence on plaque index was whether to brush teeth for the sake of oral health (B=-9.747, t=-3.752, p<0.001) or not. That made a statistically significant difference to it. The above-mentioned findings illustrated that more patients visited dental clinics than before to receive preventive dental treatment or to get dental checkups, and that toothbrushing time and whether to brush teeth for the sake of oral health or not were identified as the oral health management behaviors to affect plaque index.

• The Korean Journal of Financial Management
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• v.9 no.1
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• pp.1-23
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• 1992

CCAPM이 한국증권시장(韓國證券市場)에서 현실적(現實的)으로 성립가능한가에 대한 실증적 검증을 하였으며, 또한 시장(市場)포트폴리오와 대응되는 총소비지출의 성장률이 사전적(事前的)으로 효율적 프론티어(efficient frontier)상에 놓여 있는가에 대한 검증을 실시하였다. 이와 아울러 전통적인 S-L CAPM도 검증함으로써 CCAPM과 S-L CAPM을 비교분석(比較分析)하였다. 통계적 기법은 비선형하(非線型下)의 무관회귀분석과 GLS를 이용하였다. 1980년 1/4분기부터 1990년 4/4분기까지의 분기별 자료를 이용하여 분석한 결과, CCAPM은 전기간(全期間)을 표본으로 한 경우에 기대수익률과 위험과의 선형관계(線型關係)가 기각되었다. 그리고 전기간(全期間)을 전반기(前半期)와 후반기(後半期)로 나눈 하위기간별(下位期間別) 분석(分析)에서도 마찬가지의 결과를 얻었다. 한편 S-L CAPM의 경우에는 전기간(全期間)과 전반기(前半期)에는 선형관계가 기각되었으나 후반기(後半期)에는 채택되었다. 즉 후반기에는 위험프레미엄의 추정치가 0.05834이고 t값이 2.525로 매우 유의적이었으며 절편의 값이 통계적으로 0과 다르지 않아 실질무위험이자율(實質無危險利子率)이 0%로 추정되었다. 그런데 이는 실제로 3개월의 정기예금이자율과 소비자물가지수를 고려하여 구한 것과 일치함을 보였다. 그리고 이에 사용된 한국종합주가지수의 사전적(事前的) 효율성(效率性)은 전기간(全期間)과 하위기간(下位期間) 모두에 있는 것으로 판명되었다. 한편, CCAPM이 한국증권시장에서 기각되는 이유 중의 하나는 경기순환에 따른 생산활동(生産活動)이 즉시적으로 개별증권의 수익률에 영향을 주나 총소비지출은 이보다 비탄력적(非彈力的)인데 따른 것으로 생각되었다.

• Restorative Dentistry and Endodontics
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• v.32 no.4
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• pp.365-376
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• 2007

The purpose of this study was to evaluate the effect of different etching times on microtensile bond strength (${\mu}TBS$) to dentin both initial and after thermocycling with 3 different types of total-etching adhesives. Fifty four teeth were divided into 18 groups by etching times (5, 15, 25 sec), adhesives types (Scotchbond Multipurpose (SM), Single Bond (SB), One-Step (OS)) and number of thermocycling (0, 2,000 cycles). Flat dentin surfaces were prepared on mid-coronal dentin of extracted third molars. After exposed fresh dentin surfaces were polished with 600-grit SiC papers, each specimen was acid-etched with 35% phosphoric acid (5, 15, 25 sec) and bonded with 3 different types of total etching adhesives respectively. Then, hybrid composite Z-250 was built up. Half of them were not thermocycled (control group) and the ethers were subjected to 2,000 thermocycle (experimental group). They were sectioned occluso-gingivally into $1.0\;{\times}\;1.0\;mm^2$ composite-dentin beams and tested with universal testing machine at a crosshead speed of 1.0 mm/min. Within limited data of this study, the results were as follows 1. There was no statistically significant difference in ${\mu}TBS$ between the thermocycled and non-thermocycled groups, except for both SM and SB etched for 25 sec. 2. In thermocycled SM and SB groups, bond strength decreased by extended etching time. In total etching systems, adhesive durability for dentin could be affected by type of solvents in adhesive and etching time. Especially, extended etching time may cause deteriorate effects on bond strength when ethanol-based adhesive was used.

• Journal of Chest Surgery
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• v.31 no.5
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• pp.502-508
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• 1998

Proinflammatory cytokines such as tumor necrosis factor-$\alpha$(TNF-$\alpha$) have been implicated in myocardial and organ dysfunction associated with postperfusion syndrome. We tested the hypothesis that cytokine productions are depressed by preoperative cortiosteroid injection for cardiopulmonary bypass(CPB) and the postoperative courses will be better than without steriod pretreated cases. Cardiac surgery was performed in randomized blind fashion for 20 patients from June 1996 to September 1996. In the steroid group(n=10), corticosteroid(dexamethasone 1 mg/kg) was injected 1 hour before anesthetic induction, but in the control group(n=10), nothing was injected. Each of groups were sampled 11 times as scheduled for TNF-$\alpha$ bioassays. We have checked EKG, cardiac enzymes(CPK, LDH with isoenzyme), WBC count preoperative day, one day and three days after operation. Viatal signs were continuously monitored for three postoperaive days. In the postoperative period three patients in the control group had elevated body temperature and four patients had hypotension that required considerable intravenous fluid administration. But steroid injected patients showed normal body temperture and acceptable blood pressures without supportive treatment. CPK enzymes rose in control group higher than steroid group at postoperative 1st and 3rd day(CPK; 1122$\pm$465 vs 567$\pm$271, 864$\pm$42 vs 325$\pm$87), and CPK-MB enzymes rose in control group higher than steroid group at postoperative 1st day(106.4$\pm$115.1 vs 29.5$\pm$22.4)(P=0.02). Arterial tumor necrosis factor-$\alpha$ rose during cardiopulmonary bypass, peaking at 5 minutes before the end of aortic cross clamping(ACC-5min) in steroid group(11.9$\pm$4.7 pg/ml), and 5 minutes before the end of cardiopulmonary bypass(CPB-5min) in control group(22.3$\pm$6.8 pg/ml). The steroid pretreated patients had a shorter period of time in respirator suport time, ICU stay day, hospital admission day. We conclude that corticosteroid suppress cytokine production during and after cardiopulmonary bypass, and may improve the postoperative course through inhibition of reperfusion injury such as myocardial stunning and hemodynamic instability.

• Journal of dental hygiene science
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• v.11 no.4
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• pp.333-337
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• 2011

The purpose of this experiment was to examine possibility of microleakage by water, temperature change, and bite force inside the mouth during the period of using light-activated temporary filling materials. 2 kinds of light-activated temporary filling materials were used in order to measure weight and compressive strength and to evaluate microleakage between filling material and cavity wall according to frequency of thermal circulation. First, Light-activated temporary filling material was increased the weight, which was measured according to the period of using. As for the result of comparing between products, the weight of Quicks was indicated to be higher. Second, Compressive strength of Spacer had significant difference depending on period of using. However, significant difference wasn't shown in the compressive strength of Quicks. In Spacer that showed significant difference, the compressive strength increased greatly in the difference of 3 days. Third. As for micro-leakage according to frequency of thermal circulation, the microleakage was indicated to be the highest in the group that carried out 7,000 times. The group with operation of 1,000 times and the group with operation of 3,000 times were indicated the statistically lower micro-leakage than the group with operation of 7,000 times. This study brought about a rise in micro-leakage depending on the passage in the period of using. However, it is obvious fact that micro-leakage increases according to the passage of time after restoration.

• Journal of dental hygiene science
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• v.5 no.1
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• pp.7-12
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• 2005

This study was conducted to compare and analyze 877 cases of health insurance claims from the first half of 1999 requested to the dental centers of local health centers in rural areas and 510 identical cases from the first half of 2003. It was purposed to understand the trend of rural residents' visits to local health centers and to use the collected data as the basis needed for the vitalization of local dental cares to efficiently improve Korean citizens' dental hygiene. The results were shown as below: 1. The sexes of the visitors were fairly evenly distributed for each year. 2. Among the total of 39 types of diseases treated, 1999 had 31.9% of visits for 'Gingivitis and periodontal diseases' with 25.4% from ages between 10 and 19, for statistically attentive results. On the other hand, 2003 had 46.5% of visits for 'Oral examination' with 52.9% from ages between 0 and 9, for statistically attentive results. 3. For the distribution of age groups, majority in 1999 made visits for dental caries, gingivitis and periodontal disease, whereas majority in 2003 were for oral examination, dental caries, gingivitis and periodontal disease.

• The Korean Journal of Applied Statistics
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• v.32 no.2
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• pp.213-227
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• 2019

In this paper, we propose an end-to-end deep learning model combining Bayesian neural network with Korean speech recognition. In the past, Korean speech recognition was a complicated task due to the excessive parameters of many intermediate steps and needs for Korean expertise knowledge. Fortunately, Korean speech recognition becomes manageable with the aid of recent breakthroughs in "End-to-end" model. The end-to-end model decodes mel-frequency cepstral coefficients directly as text without any intermediate processes. Especially, Connectionist Temporal Classification loss and Attention based model are a kind of the end-to-end. In addition, we combine Bayesian neural network to implement the end-to-end model and obtain Monte Carlo estimates. Finally, we carry out our experiments on the "WorimalSam" online dictionary dataset. We obtain 4.58% Word Error Rate showing improved results compared to Google and Naver API.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.54-61
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• 2000

Amalgam, though a widely used dental material, does not bond to the tooth substrate Therefore, retentive preparation of the cavity is necessary. Such amalgam restorations, until corrosion products form and plug the margin, will show significant marginal leakage. Unless this is prevented early on, saliva and bacteria may enter the cavity causing postoperative hypersensitivity, dissolution and collapse of the restoration, discoloration of the margin and secondary caries, leading to shortened life-span of the restoration and pulpal pathosis. Recently, a method of restoration has been introduced whereby tooth material can be preserved, cavity margin can be sealed and preventive treatment of pit and fissure can be administered while retaining all the advantages of conventional amalgam restorations. Such sealed amalgams involve removing the carious lesion without extending the cavity for prevention and using pit and fissure sealants to seal cavity margins and pit and fissures to reduce microleakage. In this study, finishing of the amalgam and sealant application were performed after different intervals following of amalgam restoration to compare the microleakage of sealed and conventional amalgam restorations. Thirty bicuspids were prepared with Class V cavity preparations on the buccal and lingual surfaces. After amalgam placement, they were divided into the following groups and treated accordingly. Group 1 : Polishing after 24 hours Group 2 : Immediate sealant application without polishing Group 3 : No polishing, but sealant applied after thermocycling 500 times After treatment, the samples were thermocycled 500 times between $5^{\circ}C$ and $55^{\circ}C$ with a dwell time of 30 seconds. After thermocycling, the samples were dipped into 1% methylene blue kept in a $37^{\circ}C$ incubator at 100% humidity for 24 hours. The teeth were then embedded in resin and cut bucco-lingually along the tooth axis and observed with a stereomicroscope to determine the degree of microleakage, The following results were obtained : 1. Group 2 showed the least microleakeage, while group 1 showed the greatest. 2. Group 1 showed significantly greater microleakage compared to group 2 (p<0.05). However, no significant differences were found between group 1 and 3(p>0.05). No significant differences in microleakage were also found between cup 2 and 3(p<0.05).

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.1
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• pp.83-91
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• 2001

Purpose: The aim of this study was to investigate the current prevalence of protein-energy malnutrition (PEM) and the nutritional status of hospitalized pediatric patients. Methods: We evaluated the nutritional status of the 200 patients from February to July 1994 and the 233 patients from February to July 1999 admitted to Pediatric Department of Chosun University Hospital. Nutritional status was assessed by anthropometric and laboratory data. The nutritional status was classified according to based on the Waterlow criteria and using the laboratory data obtained between 3 days to 5 days after admission. Results: 1) The prevalence of acute PEM (weight for height) was as follows: severe, 0.5%; moderate, 7%; mild, 18%; and none, 74.5% in 1994 and severe, 2.24%; moderate, 3.59%; mild, 19.73%; and none, 74.4% in 1999. 2) The prevalence of chronic PEM (height for age) was as follows: severe, 5%; moderate, 5.5%; mild, 25.5%; and none, 64% in 1994 and severe, 2.24%; moderate, 4.04%; mild, 22.87%; and none, 70.85% in 1999. There was not a statistically significant difference between 1994 and 1999. 3) The prevalence of PEM according to age group, all age group had in general higher prevalence of mild PEM. 4) Values for hemoglobin and albumin were below than total lymphocyte values in PEM. Conclusion: The prevalence of acute or chronic PEM was common in hospitalized children. Therefore, the assessment of nutritional status may an important role to establish effective nutritional support and to improve their subsequent hospital course in hospitalized pediatric patient.

• Restorative Dentistry and Endodontics
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• v.33 no.2
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• pp.148-161
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• 2008

The purpose of this study was to evaluate the effect of chlorhexidine (CHX) on microtensile bond strength (${\mu}TBS$) of dentin bonding systems. Dentin collagenolytic and gelatinolytic activities can be suppressed by protease inhibitors, indicating that MMPs (Matrix metalloproteinases) inhibition could be beneficial in the preservation of hybrid layers. Chlorhexidine (CHX) is known as an inhibitor of MMPs activity in vitro. The experiment was proceeded as follows: At first, flat occlusal surfaces were prepared on mid-coronal dentin of extracted third molars. GI (Glass Ionomer) group was treated with dentin conditioner, and then, applied with 2 % CHX. Both SM (Scotchbond Multipurpose) and SB (Single Bond) group were applied with CHX after acid-etched with 37% phosphoric acid. TS (Clearfil Tri-S) group was applied with CHX, and then, with adhesives. Hybrid composite Z-250 and resin-modified glass ionomer Fuji-II LC was built up on experimental dentin surfaces. Half of them were subjected to 10,000 thermocycle, while the others were tested immediately. With the resulting data, statistically two-way ANOVA was performed to assess the ${\mu}TBS$ before and after thermo cycling and the effect of CHX. All statistical tests were carried out at the 95 % level of confidence. The failure mode of the testing samples was observed under a scanning electron microscopy (SEM). Within limited results, the results of this study were as follows; 1. In all experimental groups applied with 2 % chlorhexidine, the microtensile bond strength increased, and thermo cycling decreased the micro tensile bond strength (P > 0.05). 2. Compared to the thermocycling groups without chlorhexidine, those with both thermocycling and chlorhexidine showed higher microtensile bond strength, and there was significant difference especially in GI and TS groups. 3. SEM analysis of failure mode distribution revealed the adhesive failure at hybrid layer in most of the specimen. and the shift of the failure site from bottom to top of the hybrid layer with chlorhexidine groups. 2 % chlorhexidine application after acid-etching proved to preserve the durability of the hybrid layer and microtensile bond strength of dentin bonding systems.