• 한국치위생학회지
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• 제9권1호
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• pp.153-168
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• 2009

This study was executed to find out the outcome of Incremental Dental Care from September to November, 2004. 40 visitors to oral health center were examined on the oral conditions every week, seven times during above-mentioned period. Various tests were practiced in order to check their oral conditions before and after IDC such as tooth-brushing method/frequency/duration, calculus index, PHP index, halitosis and dental caries activity. Question and answer sheets were presented to student dental hygienists and 40 visitors respectively after IDC program. Results obtained are as follows. 1. Rotation method of toothbrushing increased from 27.8% to 88.9%. for men and increased from 27.3% to 95% for women. 2. Toothbrushing frequency increased from 2.8 times to 3.0 times a day for men and increased from 2.6 times to 3.1 times for women. Toothbrushing duration increased from 2.3 minutes to 2.8 minutes for men and increased from 2.1 minutes to 2.9 minutes for women. 3. Calculus index reduced from 0.5 to 0.1 for men and reduced from 0.7 to 0 for women. PHP index reduced from 3.7 to 3.0 for men and reduced 3.2 to 1.7 for women. However, halitosis didn't mark any significant difference before and after IDC. 4. Saliva buffering capacity of medium plus showed no change for men(94.5%), however increased from 95.4% to 100% for women. Dental caries activity of medium plus in S.mutans reduced by 4.3 times(72.2% to 16.7%) for men and reduced by 2 times(36.4% to 18.1%) for women. LB test results reduced by 1.5 times(50% to 33.3%) for men and reduced by 2.5 times(50% to 18.1%) for women. Alban's test results reduced by 1.4 times(83.3% to 61.1%) for men and reduced by 1.2 times(81.8% to 68.2%) for women. 5. All participants including visitors and students realized the importance of IDC and expressed a great satisfaction with IDC program. In conclusion, it is considered very necessary that IDC program should be maintained and extended to whole country so as to enhance the peoples' oral health conditions.

• Journal of Biosystems Engineering
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• 제34권5호
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• pp.325-330
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• 2009

This study was performed to develop accelerated life test methods for agricultural tractor transmission receiving variable load. To acquire parameters for calculation of accelerated life test, endurance tests were performed under different torque conditions. Test results showed that the shape factor of Weibull distribution was 1.5 and fatigue damage exponent was 5.4. The calculated test time was 5,877 hours under the conditions of average life (MTBF) 3,000 hours and 90% reliability for one test sample. According to the linear cumulative damage rule, test time could be reduced using increased test load. Test time could be reduced by 252 hours when 1.2 times of the rated load compared with 0.67 times of the rated equivalent load calculated by load spectrum of the agricultural tractor. Calculated acceleration coefficient was 23.3.

• 치위생과학회지
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• 제12권2호
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• pp.93-102
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• 2012

보건의료분야의 제반환경의 개선에도 불구하고 국민들의 구강건강상태는 아직도 OECD국가 중에서 매우 열악한 상태이다. 국민들의 구강건강을 효율적으로 증진유지하기 위해서는 중대구강병인 치아우식증을 예방하고 조기에 치료할 수 있는 구강보건진료가 이루어져야 한다. 특히 평생구강건강유지에 중요한 연령층인 초등학교학생들을 대상으로 정기적인 계속구강건강관리제도가 시급히 필요하나 초등학생 대상 계속구강건강관리방식의 치아우식예방관리법의 효과에 관한 사례가 부족한 실정이다. 따라서 광주광역시 소재의 S 치과에 2005년 12월부터 2006년 2월에 내원한 만6세에서 13세 환자 중 환자보호자의 동의를 받은 총 39명을 대상으로 실험군과 대조군으로 분류하여 치아우식활성도와 치아우식경험도를 조사하여 지역사회 치과의원에서 기초자료로 활용할 목적으로 시행한바 다음과 같은 결과를 얻었다. 1. 계속구강건강관리군의 기간별 Alban's test 및 Lactobacillius test 점수는 6개월경과 후 초진시의 1.4배에서 1.5배 감소되었고, 12개월경과 후 초진시의 1.5배에서 1.6배 감소되었다(p<0.001). 2. 계속구강건강관리군의 기간별 간이구강위생지수는 6개월과 12개월경과 후 초진시의 1.6배 감소되었다(p<0.05). 3. 12개월경과 후 우식경험영구치지수는 계속관리군(1.88개)에서 대조군(2.72개)보다 1.4배 감소되었으며, 우식영구치지수는 계속관리군(0.07개)에서 대조군(0.85개)보다 12배 감소되었다(p<0.05). 4. 12개월경과 후 제1대구치건강도는 계속관리군(98.04%)에서 대조군(95.97%)보다 1.02배 높게 나타났다(p<0.05). 이상과 같은 결과에 의하여 지역사회 치과의원에서 지속적인 계속구강건강관리제도를 시행하여 아동의 평생구강건강상태를 유지시켜야 한다고 사료되었다.

• 한국작물학회지
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• 제45권5호
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• pp.316-321
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• 2000

Blast severity data of 39 rice varieties at 11 sites in Korea from 1997 to 1999 were analyzed using AMMI model and pattern analysis. Genotype x Environment (G$\times$E) interaction sum of squares (SS) accounted for 12 % of the total SS. Eight genotype groups and seven location groups were identified based on blast reaction pattern. The data obtained from over 21 sites with 44 test varieties from 1981 to 1996 were also considered. These were compared with the 1997-1999 data using the G$\times$E analysis results. Majority of the variability in the Korean Rice Blast Nursery (KRBN) were attributable to variations due to genotypes. Variations of G$\times$E interaction were maintained though test sites were reduced from 21 to 11 sites. Broadly compatible biological discriminative varieties identified were Nagdongbyeo and Akibare while broadly incompatible biological discriminative varieties identified were Hangangchalbyeo and Seogwangbyeo. Key sites for future evaluation work could be selected from location groups. Each location group should be represented by the site with the strongest interaction pattern. Blast responses in Cheolwon, Gyehwa, Suwon, Iksan, and Icheon showed different patterns from other locations.

• 소음진동
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• 제6권2호
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• pp.215-224
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• 1996

Active vibration control is generally used to reduce vibration level by the actuators based on measured signal. Dynamic properties of a structure can be easily modified by the active vibration control, so that the vibration level may be effectively reduced to the magnitude below the allowable limit over a wide frequency rangs. In this paper, an instantaneous optimal control algorithm including acceleration feedback is presented for the active vibration control of large structures considering facts that the acceleration response can be easily measured, but the displacement and velocity response are obtained by numerically integrating the measured acceleration response with some errors. The adverse effect of the time delay is overcomed by taking into account the dynamic characteristics of an actuator and filters in the design of controller. Performance test is carried out using a hydraulic active mass driver on a test structure$(L{\times}W{\times}H;=;1200mm{\times}800mm{\times}1600mm, about;500kg)$ supported by four columns under base excitations. It is confirmed that the vibration level of the test structure are reduced to about 1/6 near resonance.

• 한국강구조학회 논문집
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• 제13권4호
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• pp.395-405
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• 2001

보-기둥 접합부의 내진성능을 향상시키기 위해 소성힌지의 발생위치를 보의 내부로 유도한 철골 모멘트 접합부에 대해 실험연구를 수행하였다. 이를 위해 보의 단면을 감소시키는 방안으로는 dogbone 접합부에서 처럼 플랜지를 감소시키는 대신에 웨브에 개구부를 설치하였다. 본 연구에서는 개구부의 형상 및 크기를 변수로 하여 총 4개의 실제 크기의 시험체에 대해 반복하중 실험을 수행하였다. 4개 시험체 모두 기둥은 $H-458{\times}417{\times}30{\times}50$, 보는 $H-792{\times}300{\times}14{\times}22$를 사용하였다. 실험결과 웨브 개구부를 이용한 접합부는 강진지역에서 철골 모멘트 연성골조에 요구되는 0.04 rad.의 총회전각을 발휘할 수 있는 것으로 나타났다.

• 재활간호학회지
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• 제18권1호
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• pp.38-45
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• 2015

Purpose: This study was attempted in order to verify the effects of moxibustion on aged back pain and activities of daily living. Methods: A research design is quasi-experiment with pre-post test design in nonequivalent control group. As for data collection and experimental treatment, it accidentally sampled totally 50 people with 24 people for the experimental group and 26 people for the control group who appeal for chronic back pain aged over 60 who visited 4 senior centers where are located in N city from November 7, 2012 to December 3, 2012. Experimental treatment was carried out moxibustion totally 12 times by 3 times for 4 weeks in the experimental group. Data analysis was made by using SPSS program. As an analytical technique, the experimental group and the control group were analyzed the homogeneity verification with t-test, Fisher's exact test and $x^2$ test and the hypothesis verification with t-test. Results: The back pain level was reduced in the experimental group than the control group. The disability of daily living activities was reduced in the experimental group than in the control group. Conclusion: Moxibustion was considered to be likely useful therapeutic method for effects of chronic back pain and disability of daily living activities in aged.

• Korean Chemical Engineering Research
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• 제58권2호
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• pp.190-196
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• 2020

공정 실험을 통하여 공정 동특성 모델을 얻는 과정은 제어시스템 설계에 있어 시간과 비용이 드는 매우 중요한 과정이다. 이를 위한 계단응답은 공정의 동특성을 이해하고 동특성 모델을 얻는 데 사용되는 오래된 하나의 정형화된 공정응답이다. 계단응답에 근거한 방법에서는 공정입력에 계단 변화를 주었을 때 나타나는 공정출력을 측정하여야 하는데, open-loop 상태로 장시간 운전해야 하는 것이 단점으로 지적된다. 이 단점을 완화하기 위하여 시간최적제어 기법을 이용하는 계단응답을 얻는 시간을 최소화 하는 방법이 제안되어 있다. 이 최적화에는 반복 계산이 필요한데, 여기서는 반복 계산이 필요 없는 방법을 제안한다. 계단응답을 위한 시간이 획기적으로 줄어드는 것을 보여주는 모사 결과들을 얻었으며, 이 방법을 제어기 자동튜닝에 응용하여 이 자동튜닝에 널리 채택되고 있는 relay feedback 자동튜닝과 비교한 모사 결과들을 제시하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.445-450
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• 2003

This study was performed 10 develop the accelerated life test method using Weibull-IPL(Inverse Power Law) model for mechanical components. Weibull-IPL model is concerned with determining the assurance life with confidence level and the accelerated life test time From the relation of weibull distribution factors and confidence limit, the testing times on the no number of failure acceptance criteria arc determined. The mechanical components generally represent wear and fatigue characteristics as a failure mode. IPL based on the cumulative damage theory is applied effectively the mechanical components to reduce the testing time and to achieve the accelerating test conditions. As the actual application example, accelerated life test method of agricultural tractor transmission was described. Life distribution of agricultural tractor transmission was supposed to follow Weibull distribution and life test time was calculated under the conditions of average life (MTBF) 3,000 hours and 90% confidence level for one test sample. According to IPL, because test time call be shorten in case increase test load test time could be reduced by 482 hours when we put the load 1.1 times of rated load than 0.73 times of rated load that is equivalent load calculated by load spectrum of the agricultural tractor. This time, acceleration coefficient was 11.7.

• 약학회지
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• 제45권5호
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• pp.491-493
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• 2001

Coagulase-negative Staphylococcus sp #39, isolated from raw-milk showed reduced susceptibility to vancomycin. The minimun inhibitory concentration for strain #39 was at 8$\mu\textrm{g}$ of vancomycin per ml. Transmitting electron microscopy displayed that this strain had a 2.5-3.5 times thicker cell wall than a vancomucin sensitive strain of Staphylococcus sp. The strain #39 also had an increased cell volume. These data indicate that the reduced susceptibility may be due to the thickness of the cell wall of the test strain.