• Journal of Korean society of Dental Hygiene
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• v.16 no.6
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• pp.969-978
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• 2016

Objectives: The purpose of the study was to examine the expected role and competency of future public health dental hygienist. Methods: This study was cross-sectional design. One dental hygienist per 16 cities and provinces was selected from the list of Korea Society of public dental hygienists. After signing in the informed consent, the interview was carried out. Transcripts were made after each interview. Six researchers recorded meaningful contents in the transcripts. They classified and integrated the information that they had recorded commonly or not. Their opinions were converged by conference. Two supervisors verified results whether they were derived from actual recordings for the reliability of the results. The records were confirmed once again and corrected into common message. Results: The main difficult subjects in public health official examination were public health, English, and medical legislation to pass the examine. The preliminary certificates included public health related certificate, computer certificate, and driver's license. In the personality aspect, creativity, activeness, cooperation and good responsibility were very important trait to public health official. Among 16 interviews, 9 were positive and 5 were negative about the future prospects of a public dental hygienist. Conclusions: The future of public health dental hygienist will be positive. Throughout effort to prepare for the public health official, the public health dental hygienist will be expanded and in many ways the dental hygienists will take the charge of the important parts of the public health administration in the near future.

• Journal of Sensor Science and Technology
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• v.7 no.1
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• pp.31-38
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• 1998

Multi-channel sensors can be used to increase the reliability and remove the random iloise in ion-sensitive field effect transistors(ISFETs). Multi-channel sensors is also an essential step toward potential fabrication of sensors for several ionic species in one device. However, when the multi-channel sensors are separately biased, the biasing problems become difficult, that is to say, the bias circuit is needed as many sensors. In this work, a circuit for biasing the four pH-ISFETs in null-balance method, where bias voltages are switched, was proposed. The proposed concept is need only one bias circuit for the four sensors. Therefore it has advantages of smaller size and lower power consumption than the case that all sensors are separately biased at a time. The proposed circuit was tested with discrete devices and its performance was investigated. In the recent trend, sensor systems are implemented as portable systems. So the verified measurement circuit was integrated by using the CMOS circuit. Fortunately, ISFET fabrication process can be compatible with CMOS process. Full circuit has a mask area of $660{\mu}m{\times}500{\mu}m$. In the future, this step will be used for developing the smart sensor system with ISFET.

• Fire Science and Engineering
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• v.31 no.2
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• pp.89-100
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• 2017

This study compared the activities satisfaction factors between volunteer firefighters and general volunteers in Sejong City. For this purpose, 112 volunteer firefighters and 227 general volunteers working in Sejong City were surveyed. In the questionnaire, the independent variable was the motivations, the interpersonal relationships, and the rewards and the dependent variable was the activities satisfaction. The reliability of the survey data in questionnaire design was analyzed by the SPSS 20.0 win program. The factor of the motivations, interpersonal relationships, and rewards had a significant positive influence on the activities satisfaction of volunteer firefighters and general volunteers (<0.05). The activities satisfaction of the volunteer firefighters was influenced in the order of the motivations, rewards, interpersonal relationships, and activities satisfaction of the general volunteers was influenced in order of the motivations, interpersonal relationships, and rewards.

• Fire Science and Engineering
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• v.28 no.1
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• pp.37-43
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• 2014

The high predictive performance of fire detector models is essentially needed to assure the reliability of fire and evacuation modeling in the process of Performance-Based fire safety Design (PBD). The main objective of the present study is to measure input information in order to predictive the accurate activation time of fixed temperature heat detectors adopted in Fire Dynamics Simulator (FDS) as a representative fire model. To end this, Fire Detector Evaluator (FDE) which could be measured the device properties of detector was used, and the spot-type fixed temperature heat detectors of two thermistor types and one bimetal type were considered as research objectors. Activation temperature and Response Time Index (RTI) of detectors required for the fire modeling were measured, and then the RTI was measured for ceiling jet flow and vertical jet flow in consideration of the install location of detectors. The results of fire modeling using measured device properties were compared and validated with the experimental results of full-scale compartment fires. It was confirmed that, in result, the numerically predicted activation time of detector showed reasonable agreement with the measured activation time.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.49-60
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• 2008

The aim of this study was to evaluate the variability of the blood.breath ratio (BBR) value and to rationalize the determination of ethanol in breath for evidential sobriety testing. In the experiment forty eight healthy persons, 24 men and 24 women, took part. The experiment included the experimental condition such as sex(2),the type of alcoholic beverage(2; soju, whisky), the type of food(2;kimchi stew, pork belly) and the amount of ethanol consumed(2; 0.35g/kg, 0.70g/kg, based on body weight ) according to 24 factorial design by orthogonal arrays. Breath and blood sample were taken each 8 times and 5 times after the end of drinking. The blood and breath alcohol measurements were highly correlated (r = 0.973). The Results of four way analyses of variance revealed a significant 'the type of food' effect for maximum BrAC (F (1, 43) =5.1, pp<.029), but no significant effect in the type of alcoholic beverage and sex. The overall blood/breath ratio (${\pm}$ SD) was 2295${\pm}$403 and the 95% confidence interval were 1489 and 3101. In spite of these variations, at this time, it seems to be reasonable that apply 2100:1 conversion factor to breathalyzers, because most of the subjects showed the blood.breath ratio of over 2100:1 at least 30 minutes or more passed from the time of drinking as shown in this study.

• Journal of Korean Society of Transportation
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• v.29 no.1
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• pp.39-46
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• 2011

Speeding is a major cause of traffic accidents that affects the safety of pedestrians and harms drivers and their families, property and mental health. However, most researches on speeding behavior have been conducted by survey method, so the relationship between cause and effect is not clear. The reliability of the research cannot be carefully examined because most researches involve retrospective methods. It is clear that conducting experimental research is important for overcoming these limitations, but it is impossible to perform tests with real cars in real traffic situations due to the inability to control situational factors (e.g., other vehicles, traffic signal) which affect participants' behavior. A car simulator experiment was designed and the theory of planned behavior was applied to the experiment. Each participant was grouped and assigned to either high speeding intention group or low speeding intention group according to their levels of speeding intention and analyzed the difference of driving behavior indexes between two groups. The results revealed statistically significant differences between two groups on driving speed, speeding frequency, and accelerator pressure deviation. Finally, the limitations and the implications of this study were discussed.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.7
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• pp.801-815
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• 2011

This study examines the characteristics of marketing and customer that influence the selection of multichannel (preference/frequency of use) in the fashion retail. The subjects of this study are men and women live in Seoul/Gyeonggi province and Busan/Gyeongsangnam-do in their 20s-40s who have shopping experiences in fashion items of more than 2 shopping channels among offline stores, catalogs, and the internet. The survey period was from March to May 2010 and 411 forms were used in this survey. The data were analyzed by a reliability analysis (Cronbach's ${\alpha}$), a factor analysis, t-test and one-way ANOVA. The main results of this study are summarized as follows. First, marketing characteristics, which effect the selection of multichannel (preference/frequency of use), consist of sales promotion, service, price, merchandise, and distribution. Those have a significant influence (***p${\leq}$.001) on choosing multichannel of fashion retail. Price has a significant impact on the preference of multichannel and merchandise affect for frequency of use in multichannel shopping. Second, customer characteristics have a significant influence (***p${\leq}$.001) on the monthly average purchasing amount, shopping hours, shopping frequency, brand knowledge, and price sensitivity. Particularly, monthly average purchasing amount & shopping frequency have meaningful differences in the frequency of using multichannel; in addition, shopping hours were affected by preference & frequency of use. Price sensitivity has a greater influence on the frequency of using multichannel and brand knowledge has a greater effect on multichannel preference. Customer's information searching characteristics have main 3 factors through the use of marketing information, personal information and experience information. Application of experience information is the main factor in preference and frequency of using multichannel shopping. The customer demographic characteristics of age (*p${\leq}$.05, **p${\leq}$.01) and gender (*p${\leq}$.05) show a difference for selecting multichannel. There is no difference for marital status, average household income per month, and job.

• The Journal of Engineering Geology
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• v.21 no.4
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• pp.361-367
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• 2011

The uniaxial compressive strength (UCS) is an important factor in the design and construction of surface and underground structures. However, the method employed to measure UCS is time consuming and expensive to apply in the field. Therefore, we developed a model to estimate UCS based on a few properties using linear regression analysis, which is a statistical method. To develop the model, valid factors from the test results were selected from a correlation analysis using a statistical program, and the model was formulated by linear regression based on the relationships among factors. UCS estimates derived from the model were compared with the results of UCS tests, to assess the reliability of the model. The relationship between rock properties and UCS indicates that the factors with the greatest influence on UCS are point load strength and shape facto r. The UCS values obtained using the model are in good agreement with the results of the UCS test. Therefore, the developed model may be used to estimate the UCS of rocks in regions with similar conditions to those of the present study area.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.7
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• pp.38-45
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• 2006

The superconducting fault current limiters(SFCLs) provide the effect such as enhancement in power system reliability due to limiting the fault current within a few miliseconds. Among various SFCLs we have developed a flux-lock type SFCL and exploited a special design to effectively reduce the fault current according to properly adjustable magnetic field after the short-circuit test. This SFCL consists of two copper coils wound in parallel on the same iron core and a component using the YBCO thin film connected in series to the secondary copper coil. Meanwhile, operating characteristics can be controlled by adjusting the inductances and the winding directions of the coils. To analyze the operational characteristics, we compared closed-loop with open-loop iron core. When the applied voltage was 200[Vrms] in the additive polarity winding, the peak values of the line current the increased up to 30.71[A] in the closed-loop and 32.01[A] in the open-loop iron core, respectively. On the other hand, in the voltages generated at current limiting elements were 220.14[V] in the closed-loop and 142.73[V] in the opal-loop iron core during first-half cycle after fault instant under the same conditions. We confirmed that the open-loop iron core had lower power burden than in the closed-loop iron core. Consequently, we found that the structure of iron core enabled the flux-lock type SFCL at power system to have the flexibility.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.183-191
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• 2015

Studies on the environment-friendly and permanent low energy saving measure are and will continue to be an eternal challenge. However, the demand is high for the technologies that can save energy significantly in everyday life that produce tangible benefits for the users by applying saving factors and that anyone can access easily when it comes the related procedure. Government policies related to the improvement of energy effect in the existing building structure are characterized by complex procedure. Moreover, cost required and reliability issue emerge when request is made to an expert. Accordingly, this study seeks to present energy improvement plan that can be utilized simply and conveniently at any place, any time by enabling customized design according to individual taste by enabling energy change amount and grade prediction when the users select only the part that they want to replace by using a simple program.