• 한국치위생학회지
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• 제16권3호
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• pp.417-426
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• 2016

Objectives: The objective of the study was to investigate the related factors of preventive behavior experience toward dental caries and periodontal disease in Korean adolescents. Methods: The study subjects were 72,060 adolescents in 800 schools who completed 2014 Korean Youth Risk Behavior Web-based survey. Dependent variables included general characteristics of the subjects, oral health behavior, and oral disease experience. The experience rate of sealant and scaling showed the prevention behavior of dental caries and periodontal disease. Data were analyzed by IBM SPSS statistics 20.0. Results: The experience rate of sealant accounted for 26.9%. The experience of sealant was related with gender, school, maternal education level, economic status, vigorous physical activity, smoking, usual stress, fruit consumption, milk consumption, soda consumption, snack consumption, tooth brushing, oral health education experience, periodontal bleeding and pain, mucosal disorders, and bad breath. The experience rate of scaling was 22.6%. The experience of scaling was related with gender, school, city division, learning achievement, maternal education level, economic status, residential type, vigorous physical activity, usual stress, fruit consumption, milk consumption, tooth brushing, oral health education experience, periodontal bleeding and pain, mucosal disorders, and bad breath. Conclusions: To expand preventive oral health behavior in the adolescents, it is necessary to support the systematic policy making and monetary establishment in the future.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.140-143
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• 2003

Air permeabilities in unsaturated fractured tuff at the Apache Leap Research Site (ALRS) near Superior, Arizona, exhibit a self-affine behavior, thus renders a field random fractal. Based up fractal scaling, the observed scale effect has been interpreted [Hyun et al., 2002]. Recently, Frantziskonis and Hansen [2000] presented that fractal scaling can be represented based on wavelets. This study deals with the way of using wavelets for fractal scaling. A numerical study is presented to examine the applicability of wavelet-based approach to determining upscaled air permeability values on various data supports at the site. To characterize the scaling property of self-affine fields generated based upon wavelets, Hurst coefficient, H. was inferred by applying the average wavelet coefficient (AWC) method. The result yielded H = 0.24, which is very close to the result of geostatistical analysis using a power variogram (H = 0.22). The study concludes that wavelet-based scaling is a useful way of determining parameter values on different data supports, which is an essential task for modeling of subsurface flow and mass transport in a numeric grid with different resolutions (grid size).

• ETRI Journal
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• 제44권5호
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• pp.849-858
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• 2022

Dynamic voltage frequency scaling (DVFS) has been widely adopted for runtime power management of various processing units. In the case of neural processing units (NPUs), power management of neural network applications is required to adjust the frequency and voltage every layer to consider the power behavior and performance of each layer. Unfortunately, DVFS is inappropriate for layer-wise run-time power management of NPUs due to the long latency of voltage scaling compared with each layer execution time. Because the frequency scaling is fast enough to keep up with each layer, we propose a layerwise dynamic frequency scaling (DFS) technique for an NPU. Our proposed DFS exploits the highest frequency under the power limit of an NPU for each layer. To determine the highest allowable frequency, we build a power model to predict the power consumption of an NPU based on a real measurement on the fabricated NPU. Our evaluation results show that our proposed DFS improves frame per second (FPS) by 33% and saves energy by 14% on average, compared with DVFS.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.1052-1065
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• 2024

Advanced Pressurized Water Reactors (APWRs) and Boiling Water Reactors (BWRs) employ a suppression pool as a heat sink to prevent containment overpressure. Steam can be discharged into the pool through multi-hole spargers or blowdown pipes in both normal and accident conditions. Direct Contact Condensation (DCC) creates sources of momentum and heat. The competition between these two sources determines the development of thermal stratification or mixing of the pool. Thermal stratification is of safety concern as it reduces the cooling capability compared to a completely mixed pool condition. In this work we develop a scaling approach to prediction of the thermal stratification in a water pool induced by steam injection through spargers. Experimental data obtained from large-scale pool tests conducted in the PPOOLEX and PANDA facilities, as well as simulation results obtained using validated codes are used to develop the scaling. Two injection orientations, namely radial injection through multi-hole Sparger Head (SH) and vertical injection through Load Reduction Ring (LRR), are considered. We show that the erosion rate of the cold layer can be estimated using the Richardson number. In this work, scaling laws are proposed to estimate both the (i) transient erosion velocity and (ii) the stable position of the thermocline. These scaling laws are then implemented into a 1D model to simulate the thermal behavior of the pool during steam injection through the sparger.

• 한국산학기술학회논문지
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• 제17권1호
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• pp.629-637
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• 2016

본 연구는 구강관리행태와의 연관성과 설태지수, 치석, 스케일링 전후의 구강환경에 따른 구취변화를 알아보고자 대전광역시에 위치한 K대학교 치위생학과에 스케일링 실습을 위해 내방한 참여자 130명을 대상으로 설태지수와 구취를 조사하여 조사하였다. 모든 조사대상자에 대하여 설문조사, 설태지수와 치면세균막과 치석정도를 측정한 구강검사, 구취측정 등을 하였다. 그 결과 설태가 구취에 가장 큰 영향을 준다는 것을 확인할 수 있었고, 이러한 설태지수는 흡연과 혀 닦기와 관련이 높았다. 또한 구취는 잇솔질 횟수가 많을수록 낮은 수치를 보였고 비외과적 치료인 스케일링을 통해 구취감소의 효과가 나타났으며, 나이와 설태지수가 관련요인임을 확인하였다. 이에 적절한 구강관리를 실천하여 치태과 설태의 양을 줄이고 정기적인 스케일링을 받음으로써 구강건강증진은 물론 구취감소의 효과를 얻어야 할 것이다.

• 보건교육건강증진학회지
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• 제22권1호
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• pp.1-16
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• 2005

The study was performed to examine the scaling behavior about dental health. The subjects of this study were 700 workers selected in Daegu. This survey was carried out during 2003. 7. 15 - 2003. 7. 31. The results of this study can be summarized as follows. 1. Distribution of respondent's class was male of $53.5\%, female of $46.2\%, and 30's age of $36.2\%, 20's age of $28.2\%. Concerning about dental health was appeared that female was higher rate than male. also, difference was related in their age, working department and residence. 2. In case of no experience to scaling for past 3 years was appeared that male of $67.6\% was higher rate than female of $56.8\%. The frequency of treat scaling was appeared that $46.2\% of the subjects was treated scaling per year. 3. The root cause of no treatment by regular was appeared that 'high expensive' was most high with $38.0\% and 2nd, 'didn't felt importance' was $24.2\%, 3rd 'lack of spare time' was $20.7\%, the last ranking 'only be frightened' was $14.3\%. 4. Method of learning knowledge about scaling was appeared that male and female were similar with their method of it. knowledge level of scaling was learned by internet were higher in worker of 20's age than any other age. also, other difference was related in school career and residence. Opinion about necessity of scaling answer which need or surely need were similar to male of $67.1\% and female of $72.6\%. 5. As for knowledge of scaling was appeared that male of $94.3\% and female of $87.1\% had corrective knowledge. The right answer was significantly different by ages, school career, working department and residence.

• Korean Chemical Engineering Research
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• 제60권2호
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• pp.260-266
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• 2022

Average aggregate size in particulate suspensions is estimated with scaling theories based on fractal concept and elasticity of colloidal gel. The scaling theories are used to determine structure parameters of the aggregates, i.e., fractal dimension and power-law exponent for aggregate size reduction with shear stress using scaling behavior of elastic modulus and shear yield stress as a function of particle concentration. The structure parameters are utilized to predict aggregate size which varies with shear stress through rheological modeling. Experimentally rheological measurement is conducted for aqueous suspension of zinc oxide particles with average diameter of 110 nm. The predicted aggregate size is about 1135 nm at 1 s^-1 and 739 nm at 1000 s^-1 on the average over the particle concentrations. It has been found that the predicted aggregate size near 0.1 s^-1 agrees with that the measured one by a dynamic light scattering analyzer operated un-sheared.

• 한국자기학회지
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• 제25권6호
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• pp.180-184
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• 2015

실시간 자구 관찰이 가능한 광자기 현미경을 이용하여 강자성 나노자성체 CoFe 박막에서의 자화역전현상을 연구하였다. 흥미롭게도, 박막의 두께가 증가함에 따라 자구벽의 운동이 단일 자구벽의 운동 성향에서 무작위적인 자구들의 역전 성향으로 변함을 알 수 있었다. 또한, 자구벽 운동에서의 자구들의 점프사이즈들의 통계적인 해석 결과, CoFe박막에서의 자구역전현상이 임계지수 ${\tau}{\sim}1.33$를 가지는 임계축척현상을 보임을 알 수 있었다.

• 한국치위생학회지
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• 제15권1호
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• pp.119-127
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• 2015

Objectives: The purpose of the study is to investigate the relationship between dental caries and oral health behaviors in middle and high school students by web-based survey of the ninth(2013) Korean youth risk behavior. Methods: The subjects were 75,149 students from 400 middle schools and 400 high schools. Finally, the survey participation rate was 96.4%(72,435 students from 799 schools) by complex sample design. The questionnaire consisted of general characteristics of the subjects, oral health behaviors, and oral health status. General characteristics included gender, types of schools, economic condition, and residential types. Oral health behaviors included subjective oral health condition, frequency of tooth brushing, tooth brushing after meal within recent 7 days, sealant within 12 months, fluoride application within 12 months, scaling within 12 months, and oral health education experience within 12 months. Oral health condition included dental caries incidence within 12 months. Results: Oral health behavior influenced on dental caries in the middle and high school students in Korea. This study showed the relationship between the sociodemographic characteristics, tooth brushing frequency, sealant experience, dental caries and halitosis experience, and scaling within 12 months. Scaling is the best prevention method for dental caries and halitosis in the students. Conclusions: The study showed the necessity for practical oral health education and the effect of fluoride application for dental caries prevention.

• Korean Chemical Engineering Research
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• 제60권1호
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• pp.125-131
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• 2022

The microstructure of highly aggregated colloidal dispersions was investigated by probing the rheological behavior of magnetic suspensions. The dynamic moduli as functions of frequency and strain amplitude are shown to closely resemble that of colloidal gels indicating the formation of network structure. The two types of characteristic critical strain amplitudes, γ_c and γ_y, were characterized in terms of the changing microstructure. The amplitude of γ_c indicates the transition from linear to nonlinear viscoelasticity and depends only on particle volume fraction not magnetic interactions. The study of scaling behavior suggests that it is related to the breakage of interfloc, i.e., floc-floc structure. However, yielding strain, γ_y, was found to be independent of particle volume fraction as well as magnetic interaction. It relates to extensive deformation resulting in yielding behavior. The scaling of elastic constant, G_e, implies that this yielding behavior and hence γ_y is due to the breakage of long-range interfloc interactions. Also, the deformation of flocs due to increase strain was indicated from the investigation of the fractal nature.