• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.41-53
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• 2015

In meteorological field, many researchers have tried to develop micro scale weather analysis modules for providing real-time weather information service in the metropolitan area. This effort enables us to cope with various economic and social harms coming from serious change in the micro meteorology of a metropolitan area due to rapid urbanization such as quantitative expansions in its urban activity, growth of population, and building concentration. The accuracy of the micro scale weather analysis modules (MSWAM) directly related to usefulness and quality of the real-time weather information service in the metropolitan area. This paper design a evaluation system along with verification tools that sufficiently accommodate spatio-temporal characteristics of the outputs of the MSWAM. For this we proposes a test for the equality of mean vectors of the output series of the MSWAM and corresponding observed time series by using a spectral analysis technique. As a byproduct, a time series cluster analysis method, using a function of the test statistic as the distance measure, is developed. A real data application is given to demonstrate the utility of the method.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.4
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• pp.295-303
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• 2004

In order to estimate the effect of ceramic artificial reefs on the fisheries resources enhancement, we have studied the variation of catch and species, which were caught by trammel net on the three fishing grounds of ceramic artificial reef, natural reef, and control(non-reef)in the coast of Geomun-do, Korea from 2001 to 2003. Catch per unit effort (CPUE ; g/panel) of fishing ground with the ceramic artificial reef area was 1,621.9g, it was about 67.9% higher than the natural reef area 333.3% higher than the control area. The catch of fish with the ceramic artificial and the natural reef area was not significantly different based on statistical analysis of Tukey test, whereas the relationship between the ceramic artificial reef and the control area was significantly different (p<0.05). Monthly mean number of species caught by the artificial reef area, the natural reef area and the control area was no difference by ANOVA test. The catch of fish was highest in November and lowest in May, whish was associated with the natural reef and the control area. The dominant species were demersal fishes living around rock such as Pagrus majir, Thamnaconus modestus, Stephanolepis sirrhifer, Pleuronichthys curntus, and Ostracion cubicus in the artificial reef area, but demersal of migratory fishes in the natural reef and the control area.

• Journal of Korean society of Dental Hygiene
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• v.10 no.5
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• pp.831-839
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• 2010

Objectives : The purpose of this study was to examine dental hygiene students' image of dental hygienist and factors affecting the image of dental hygienist in an effort to provide some information useful for dental hygiene education. It's basically meant to recreate the image of dental hygienist as a professional. Methods : The subjects in this study were 310 sophomores and seniors who ere selected by convenience sampling from three different three-year-course colleges located in Gyeonggi Province, Chungcheong Province and Gwangju. After a survey was conducted, the answer sheets from 277 respondents were analyzed except for 33 incomplete ones. The collected data were analyzed with a SPSSWIN 17.0 program, and statistical data on frequency and percentage were obtained to find out the general characteristics of the subjects, and another statistical data on mean and standard deviation for each item were acquired to check their image of dental hygienist. Besides, t-test, ANOVA and Kruscal-Wallis test, one of nonparametric test, were utilized to look for connections between their general characteristics and image of dental hygienist. Results : 1. They gave a mean of 3.53 to the image of dental hygienist, which showed that the dental hygiene students took a favorable view of dental hygienists in general. 2. Their response to four items showed that they looked at the image of dental hygienist in a positive manner. The four items respectively described dental hygienists as professionals, as ones who played a crucial role in the improvement of national oral health, as ones with professional knowledge and sophisticated knowhow, and as neat and decent people. And their response to the following five items indicated that they looked at the image of dental hygienists in a negative way. One was that dental hygienists were considered to be dental nurses, and another was that the occupation of dental hygienist was a demanding and stressful job. The third was that there was no single, fixed title to call dental hygienists, and the fourth was that dental hygiene wasn't recognized as an independent area. The fifth was that the social standing of dental hygienists was sort of high. 3. In regard to the impact of the general characteristics of the dental hygiene students on their image of dental hygienist, they had a more favorable image of dental hygienist when they perceived dental hygiene in a more positive manner(p<0.001). Conclusions : In order to boost the image of dental hygienist, the working conditions of dental hygienists should be improved, and educational programs should be prepared to provided them extended continuing educational opportunities. And the kind of educational environments that could nurture dental hygienists who are convinced and have a vision should be created.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.8
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• pp.597-609
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• 2020

These days, the coaxial rotor system is used for various purposes like UAVs, Mars exploration helicopters, and the next-generation high-speed rotorcraft. A number of research projects on aerodynamic performance of rotor systems, including the coaxial configuration have been made previously. On the contrary, research on rotor blade deformation has been mainly carried out regarding the single rotor system, where such effort has not been enough on the coaxial system. Nonetheless, in case of the coaxial system, blade deformation analysis is much more important because of the complex air flow around the rotors, and that the distance between the two rotors is a key factor affects aerodynamic performance of the entire system. For these reasons, an experimental study on rotor blade deformation of the coaxial system was conducted using the Stereo Pattern Recognition(SPR) technique, one of the state-of-the-art of photogrammetry method. In this research, a small-scale coaxial rotor test stand designed by Korea Aerospace Research Institute(KARI) was used. With the same test stand, performance of the coaxial configuration had been studied before the experimental study on blade deformation, in order to find the relation between performance and blade deformation of the rotor system. Results of the performance test and the deformation study are presented in this article.

• Journal of Radiation Protection and Research
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• v.31 no.3
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• pp.155-164
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• 2006

It is judged that there could be certainty in every process of analyzing environmental samples using Liquid Scintillation Counter. Therefore, this study focuses on quantitative evaluation on uncertainty in an effort to analyze comparatively accurately environmental samples. For this, after parameters which can have an effect on uncertainty was derived, the evaluation on each parameter was tamed out. The results of analysis of each parameter showed that the effect according to the weight difference of Teflon vial did not appear, and that standard deviations of SQP(E) averages reached saturation point at $75{\sim}90$ sec at the result of making increases step by step the irradiation time of External standard, and that values measured by repeat method produces good results compared with replicate. Also, conclusion was derived that analysis on sample after it is left in cold and dark room at least above 1,000 minutes have to be carried out, and the result of carrying out verification on results measured as well as equipment itself using radioactivity-error-analysis and chi-square test, resonable result was derived.

• Journal of Preventive Medicine and Public Health
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• v.30 no.2 s.57
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• pp.356-368
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• 1997

In effort to determine whether aircraft noise can have health effects such as hearing loss, hypertension and psychological stress, a total of 111 male professors and administrative officers working a college near a military airport in Korea(exposed group) and a total of 168 males and 112 females matched by age groups(control groups) were analyzed. Personal noise exposure and indoor and outdoor sound level of jet aircraft noise were measured at the exposed are3. And pure tone, air conduction test and measurement of blood pressure were given to the exposed(males) and matched control groups (males and females). BEPSI(Brief Encounter Psychological Instrument) and psychological response to aircraft noise were examined for the exposed group. The noise dosimetry results revealed time-weighted averages(TWAs) that ranged from 61 to 68 dBA. However the levels encountered during taking off jet airplanes reached 126 dBA for two half minutes time period. Th, audiometric, test showed that mean values of HTL(hearing threshold level) in exposed group at every frequency(500, 1,000, 2,000, 4,000, and 8,000 Hz were much lower than them of male and female control groups. And in old age groups, interaction of age and noise was observed at 8,000 Hz in both ears(p<0.05). Conclusively, aircraft noise does not appear to induce hearing loss directly in high frequency, but may decreased hearing threshold level by interaction of aging process and noise exposure. However, difference of mean values of exposed and control groups on blood pressure was not significantly. In psychological test, annoyance was the most severe psychological response to noise in exposed group, but mean value of BEPSI was not correlated with job duration in exposed group.

• Journal of Korea Game Society
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• v.11 no.5
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• pp.67-78
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• 2011

This paper introduces an efficient and satisfactory search interface that enables users to browse and find the video data they want from a massively huge video database widely used in various multimedia environment. The target user group is information analysts at US defense industry or governmental intelligence agencies whose job is to identify a certain person from a lot of video footage taken from CCTV(Closed-circuit Television) cameras. For the first user test, we suggested the CAVE-like virtual reality interface to be the most optimal for the tasks we designed for, so we compared this interface with desktop interface. The softwares and database developed and optimized for each task were used in this user test. For the second user test, we researched on what input devices would be most optimal for enhancing efficiency of search task in the CAVE-like virtual reality system. Especially we focused our effort on measuring the effectiveness and user satisfaction of three different types of devices that embody gestural interface input system that encourages users' ergonomic control of the interface. We also measured the time consumed for performing each task to find out the most efficient input device among the ones tested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.3220-3226
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• 2011

In order to monitor internal risk factors such as fire, terror, etc. on the subway station, the surveillance systems using CCTV and various kinds of sensors have been implemented and recently, introduction of surveillance systems using an advanced IT technology, sensor network technology is tried on several areas. Since 2007, Korean government has made an effort to develop the intelligent surveillance and monitoring system, which can monitor fire, intrusion, passenger congestion, health-state of structure, etc., by using wireless sensor network technology and intelligent video analytic technique. For that purpose, this study carried out field wireless communication environment test on Chungmuro Station of Seoul Metro on the basis of ZigBee that is considered as a representative wireless sensor network before field application of the intelligent integrated surveillance system being developed, arranged and analyzed and ZigBee based wireless communication environment test results on the platform and waiting room of Chungmuro Station on this paper. Results of wireless spectrum analysis on the platform and waiting room showed that there is no radio frequency overlapped with that of ZigBee based sensor network and no frequency interference with adjacent frequencies separated 10MHz or more. As results of wireless data transmission test using ZigBee showed that data transmission is influenced by multi-path fading effect from the number and flow rate of passengers on the platform or the waiting room rather than effects from entrance and exit of the train to/from the platform, it should be considered when implementing the intelligent integrated surveillance system on the station.

• Journal of the Korean earth science society
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• v.44 no.2
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• pp.169-183
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• 2023

This study analyzed students' polar literacy in an effort to promote polar education based on its high educational value. The polar literacy test items developed for this study consisted of questions about knowledge, skills, attitudes, and beliefs about the polar region, as well as background variables of students. The final test items, which were revised and supplemented several times through the preliminary test, were applied to 323 eighth graders in South Korea. We analyzed the response characteristics of the polar literacy questions for all students. Students were grouped into those with a global citizenship perspective and those with a pragmatic perspective, according to the viewpoint of polar issues and their polar literacy. Analysis showed that the students had a high understanding of climate change and living things in the polar regions, but had a very low understanding of ice, which is a key component of the polar regions. Moreover, they were unable to approach the Earth system thinking when dealing with polar issues. In addition, the global citizenship group had a higher intellectual understanding and deeper sympathy of the polar problem than the pragmatic group. This study is meaningful in that the survey results present a specific direction for future polar education.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4A
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• pp.281-290
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• 2009

In this study, an analysis technique of hybrid girder considering nonlinearity of steel-concrete contact surface is presented. Steel-concrete hybrid girder shows partial-interaction behavior due to the deformation of shear connectors, slip and detachment at the interface, and cracks under the applied loads. Therefore, the partial-interaction approach becomes more reasonable. Contact surface is modeled by interface element and analyzed nonlinearly because of cost of time and effort to detailed model and analysis. Steel and Concrete are modeled considering non-linearity of materials. Material property of contact surface is obtained from push-out test and input to interface element. For the constitutive models, Drucker-Prager and smeared cracking model are used for concrete in compression and tension, respectively, and a von-Mises model is used for steel. This analysis technique is verified by comparing it with test results. Using verified analysis technique, various analyses are performed with different parameters such as nonlinear material property of interface element and prestress. The results are compared with linear analysis result and analysis result with the assumption of full-interaction.