• Journal of dental hygiene science
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• v.3 no.1
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• pp.23-31
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• 2003

In this research, dental health awareness of 3rd graders of high schools in Icheon-city was investigated in order to use the result of this research as the basic data for school dental health program, education direction, and educational purpose. The research was done from Sep. 23. to Oct. 5 and the followings are the results of survey. (1) 85.0% of the students brush their teeth once or twice a day and more female students brush their teeth 3 times a day than male students. (2) 77% of the students had experienced dental caries and 38.0% of the students have periodontal disease, which has lower percentage than cavity. (3) Most of the students can not go to the dentists because they do not have time and 84.0% of the students have been treated in dental clinics so this tells that most of the students had experienced dental treatment. (4) 46.8% of the students had interests in dental health and male students showed more interests than female students and the difference was statistically significant(p<0.05). (5) Most of the students hear the importance and information of dental health from mass media such as TV and radio or from people around. The research shows that most of the students do not get periodic dental checkups. (6) 80.8% of the students had never taught dental health education for improvement of dental health and 76.2% of the students think that the dental health education is needed. There was no difference according to the gender. (7) Most of the students think that the dental health education is needed to prevent cavity and gingiva disease and it shows that more students tend to attend the dental health education. (8) 69.3% of the students think that brushing your teeth is important to maintain good dental health and there was no difference according to the gender. Most of the students weren't aware that periodic dental checkups, right brushing, and using fluoric toothpaste is effective for cavity protection. (9) After looking into the knowledge of the students on dental health, it shows that the knowledge is low and there is no difference according to the gender.

• Journal of the Korean Geosynthetics Society
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• v.17 no.2
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• pp.41-49
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• 2018

The purpose of this study is to fabricate a full scale road embankment using lightweight air foamed soil as a soil material on soft ground and to investigate its material characteristics and behavior in order to promote dredged soil utilization and minimize ground improvement. As a result of the laboratory test of the onsite mixed samples, the total unit weight of the specimens decreased almost linearly until curing 28 days. In particular, the total unit weight after 28 days of curing was reduced to about 81% of the slurry state before curing, which will be useful in the formulation of similar native soil materials in the future. The unconfined compressive strength began to decrease with the 14th day of curing as shown in the previous study. When the cement content is increased, the strength decreases sharply at a small strain change after the occurrence of the maximum compressive strength, and the maximum strength is exhibited in a range of a smaller axial strain than normal range. The settlement at the surface layer of the ground due to the lightweight embankment was about 1 / 2.75 of the soil embankment and was in agreement with the unit weight ratio (1 / 2.7) of the embankment materials. This indicates the cause and effect of the settlement due to the difference in self weight of the embankments. Also, the difference in settlement between soil and lightweight embankment increased with increasing depth. This shows that the difference in the point at which the settlement is terminated is clear. The ground horizontal displacement under the lightweight embankment was about 15~20% smaller than that of the soil embankment and the depth of occurrence was also 4.5~5.0m shallower in the lightweight embankment.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.390-397
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• 2013

The study, utilizing a data envelopment analysis (DEA) which is one of the nonparametric estimation methods, aims to evaluate the management efficiency of chestnut tree cultivators in such provinces in Chungchungnam-do as Cheong-yang, Gong-ju, Bu-yeo and so on. The analysis data of this study is based on inputs and outputs of 20 forestry households surveyed in the 2012 survey titled 'A Study on Current Level and Condition of Chestnut Cultivation and Management', which was conducted from March 2012 to October 2012. The elements of inputs are composed of management cost, harvesting cost, material cost, non-operation expenses and cultivation area, while the element of output is a gross margin only. Then the study analyzes a technical efficiency, a puretechnical efficiency and a scale efficiency using CCR and BCC model among DEA methods. Based on that, it also provides improvement methods for forestry households that turned out to be inefficient. In order to verify the result of DEA analysis, the study additionally compares a result of this efficiency study with that of chestnuts management standard diagnostic table. According to the result, the average value of technical efficiency analyzed was 0.667, proving to be inefficient in general. Given that the average value of pure-technical efficiency was 0.944 and that of scale efficiency was 0.703, it can be inferred that inefficiency exists in the field of scale, not in the field of cultivation techniques. As for forestry households with the efficiency score of 1, it is shown that there were 6 households that recorded 1 in the technical efficiency field and 13 households that recorded 1 in the pure technical efficiency. Meanwhile, there were 6 households that recorded 1 in all of the three aspects. In the comparison with the scores from chestnuts management standard diagnostic table, there were 5 households made a high score of over 80, among which are 3 households with score 1 in the technical efficiency. Also, the results of this study and the chestnuts management standard diagnostic table are proved to have the same result, both of them showing the same households that recorded the highest score and the lowest score. This means the management efficiency evaluation using DEA can be applied to the fieldwork along with the chestnuts management standard diagnostic table.

• Journal of Family Resource Management and Policy Review
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• v.17 no.4
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• pp.19-37
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• 2013

From the perspective of labor welfare, forty-hour-a-week working system:(FWS) has been an important goal throughout world, and in fact, advanced countries implemented this a long time ago. However, there are differences in opinions concerning FWS; some people emphasizes the improvement in life quality, while others point out that this measure increases the cost of wages and has limited effectiveness. Thus, discussions about the success of FWS have emerged from diverse perspectives; One thing that should be made clear before debating FWS is that reducing laborers' working hours is already a global trend, and Korea, also intends to extend it. Therefore, in order to maximize the benefits resulting from the execution of the system and to identify measures that can be used to solve the problems related to FWS, it is necessary to consider actual laborers' use of leisure resources and whether they have increased or decreased as a result of FWS. It is also necessary to look at the differences in workers' leisure activity with and without the system. To evaluate and diagnose FWS's political effect from the perspective of laborers' leisure satisfaction and improvements in life quality, this study examines differences in leisure expenses, leisure hours, use of and demand for leisure resources such as leisure space, and types of leisure activity, according to the execution of FWS, This research is based on the "2012 Survey on National Leisure Activity" conducted by the Ministry of Culture, Sports and Tourism. In addition, through analysis of the differences in leisure satisfaction and happiness levels, the study intends to confirm the necessity of executing FWS and ensuring that the system is in use. The study results can be briefly summed up as followa:: First, regarding the general findings of the study, a significant result was shown in terms of the execution of FWS according to income level. The finding that the execution of FWS works differently according to the working environment or life quality reassures us of the common notion in society that working environment or life quality may differ in relation to social characteristics. The utility of weekday leisure hours did not indicate a statistically significant difference, but in terms of weekend leisure hours, laborers practicing FWS had an additional 30 minutes of leisure time than those who did not. Furthermore, regarding leisure expenses, laborers practicing FWS indicated more monthly average leisure expenses or expected leisure expenses. In relation to leisure activity, those working at a company executing FWS engaged in culture and art activities more frequently than those working at the companies that did not. On the other hand, those working at companies without FWS indicated more hobbies, amusement activities, rest, and other activities than those working at the companies with FWS. In terms of vacation experience, those working at companies with FWS had more vacation time than those working at companies without it; on average, they had longer vacations by 1.64 days. Regarding their leisure life satisfaction and happiness level, those working at companies with FWS indicated higher satisfaction and greater happiness than those working at companies without it. The findings mentioned above represent the preliminary results of this paper, and the remainder of the research will provide more detailed analysis results and suggestions corresponding to them.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.2
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• pp.1-13
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• 2008

Bus stops are places that a variety of things happen including waiting, meeting and taking breaks. Therefore, these locations need to be made to meet the usage demands. They should be landscaped to provide a comfortable and satisfying environment for users. At present, bus stops are made with artificial materials and are all unified in form without consideration to landscape, ecology and other characteristics. Users are exposed to the poor surroundings. However, if small urban parks, which are of vital importance as well as extremely convenient, were connected to bus stops, the results would be a quantitative increase in the leisure locations and a qualitative change in the form of improved landscape and various forms of parks. The research was carried out to determine the effects of connecting bus stops and small parks, and the results are as follows. First, small parks provide resting areas for waiting passengers and buses. Second, it provides presently insufficient rest areas with convenience facilities and makes it more comfortable to take buses and use the park. Third, it provides a multi-functional efficient use of space that functions as both bus stop and park. Fourth, it can be a symbolic landmark that can represent the color of the area by adding a cultural element. Fifth, the existing green space in the park can contribute to the natural environment of the city. This study deduced general problems surrounding bus stops on the basis of selected indices and researched bus stops which are being used as parks and the places which have the potential for such purposes, in order to suggest a plan of attack. In addition, this proposal can create a new form of space, the bus stop park, and try to create a module of cases to establish it.

• Journal of agricultural medicine and community health
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• v.27 no.2
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• pp.35-54
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• 2002

This study was performed to investigate the task status and performance improvement plan of dental hygienists of Health Centers and Subcenters. The Data collected by self-administered Questionnaire survey of 203 dental hygienists of Health Centers and Subcenters located in Gyeongsangbuk-do were analyzed. The major results are as follows: For the degree of satisfaction in tasks, 73.9% of dental hygienists of Health Centers and Subcenters felt proud, 52.2% felt overwork, 32.0% hoped transferring to other worksite and the major reason of transferring was lack of promotion opportunity in officials of dental hygiene department. Dental hygienists received job education in addition continuous job education in last 3 years were 47.3%, 19.2% of dental hygienists performed the special dental health program for residents in last 3years. Almost half(53.7%) of dental hygienists replied that dental hygienists who were not engaged in dental health tasks should be engaged in dental health tasks. The major dental hygienic tasks performed by dental hygienic officials were support for dental treatment(41.6%). Dental hygienic officials answered that dental health tasks, school dental health program, vertical dental health program should be conducted as important tasks in order. And they replied that the most serious problem of dental hygienic tasks was not conducting dental health affairs due to 'lack of dental doctor'(40.9%), 'lack of concern for dental health tasks'(26.4%), and 'lack of budget and personnels for dental tasks'(19.0%), and the most important thing to improve dental hygienic tasks was 'posting dental hygienists in ministry of health and welfare(MOHW) and province', 'securing of budget and personnels for dental health tasks'.

• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.469-487
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• 2007

Grain-Size Trend Analysis is the methodology to identify net sediment transport pathways, based on the assumption that the movement of sediment from the source to deposit leaves the identifiable spatial pattern of mean, sorting, and skewness of grain size. It can easily be implemented with low cost, so it has great potentials to contribute to geomorphological research, whereas it can also be used inadequately without recognition of its limitations. This research aims to compare three established methods of grain-size trend analysis to search for the adequate way of application, and also suggest the research tasks needed in improving this methodology 1D pathway method can corporate the field experience into analyzing the pathway, provide the useful information of depositional environments through X-distribution, and identify the long-term trend effectively. However, it has disadvantage of the dependence on subjective interpretation, and a relatively coarse temporal scale. Gao-Collins's 2D transport vector method has the objective procedure, has the capability to visualize the transport pattern in 2D format, and to identify the pattern at a finer temporal scale, whereas characteristic distance and semiquantitative filtering are controversial. Le Roux's alternative 2D transport vector method has two improvement of Gao-Collins's in that it expands the empirical rules, considers the gradient of each parameters as well as the order, and has the ability to identify the pattern at a finer temporal scale, while the basic concepts are arbitrary and complicated. The application of grain sire trend analysis requires the selection of adequate method and the design of proper sampling scheme, based on the field knowledge of researcher, the temporal scale of sediment transport pattern targeted, and information needed. Besides, the relationship between the depth of sample and representative temporal scale should be systematically investigated in improving this methodology.

• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.3-14
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• 2015

Since the global financial crisis, the Korean domestic construction market has continuously experienced downturns, and the Korean domain construction firms'profitability has been persistently deteriorated. Domestic construction firms have rapidly advanced to overseas markets exclusively for the construction contract packages. However, the profitability for the construction contracts has been lower compared to engineering or project management contracts. One of the critical issues the Korean firms have faced was project management capability across all phases in project execution. Even though several project management capability assessment tools were introduced, most tools were applicable to a wide variety of industry sectors rather than construction industry. Project management capability assessment tool specifically applicable to domestic CM firms was developed through this research, in order to assess project and program management capabilities and improve the competitiveness in overseas market Also, the correlation between project, programs, and the CM infrastructure were identified. The CM firms were divided into two groups according to the size of the business, and both were evaluated at the project and the program level based for the 9 different criteria. The project management capability assessment tool developed for the CM firms can be used for self-assessment to distinguish the strengths and weaknesses of each company at the project and program level. In addition, the current status of each group can be identified by spotting improvement areas for the management capabilities.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.375-375
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• 2010

CdTe as an absorber material is widely used in thin film solar cells with the heterostructure due to its almost ideal band gap energy of 1.45 eV, high photovoltaic conversion efficiency, low cost and stable performance. The deposition methods and preparation conditions for the fabrication of CdTe are very important for the achievement of high solar cell conversion efficiency. There are some rearranged reports about the deposition methods available for the preparation of CdTe thin films such as close spaced sublimation (CSS), physical vapor deposition (PVD), vacuum evaporation, vapor transport deposition (VTD), closed space vapor transport, electrodeposition, screen printing, spray pyrolysis, metalorganic chemical vapor deposition (MOCVD), and RF sputtering. The RF sputtering method for the preparation of CdTe thin films has important advantages in that the thin films can be prepared at low growth temperatures with large-area deposition suitable for mass-production. The authors reported that the optical and electrical properties of CdTe thin film were closely connected by the thickness-uniformity of the film in the previous study [1], which means that the better optical absorbance and the higher carrier concentration could be obtained in the better condition of thickness-uniformity for CdTe thin film. The thickness-uniformity could be controlled and improved by the some process parameters such as vacuum level and RF power in the sputtering process of CdTe thin films. However, there is a limitation to improve the thickness-uniformity only in the preparation process [1]. So it is necessary to introduce the external or additional method for improving the thickness-uniformity of CdTe thin film because the cell size of thin film solar cell will be enlarged. Therefore, the authors firstly applied the chemical mechanical polishing (CMP) process to improving the thickness-uniformity of CdTe thin films with a G&P POLI-450 CMP polisher [2]. CMP process is the most important process in semiconductor manufacturing processes in order to planarize the surface of the wafer even over 300 mm and to form the copper interconnects with damascene process. Some important CMP characteristics for CdTe were obtained including removal rate (RR), WIWNU%, RMS roughness, and peak-to-valley roughness [2]. With these important results, the CMP process for CdTe thin films was performed to improve the thickness-uniformity of the sputtering-deposited CdTe thin film which had the worst two thickness-uniformities of them. Some optical properties including optical transmittance and absorbance of the CdTe thin films were measured by using a UV-Visible spectrophotometer (Varian Techtron, Cary500scan) in the range of 400 - 800 nm. After CMP process, the thickness-uniformities became better than that of the best condition in the previous sputtering process of CdTe thin films. Consequently, the optical properties were directly affected by the thickness-uniformity of CdTe thin film. The absorbance of CdTe thin films was improved although the thickness of CdTe thin film was not changed.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.3
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• pp.95-126
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• 2020

In 2017, the world's first WIG ship (WIG: Wing In-Ground) pilot's license written test was conducted in Korea. The WIG ship is a ship that combines the characteristics of ships and airplanes. Therefore, the pilot of the WIG ship was allowed to apply only for those who had the aircraft pilot's license and the 6th class marine nautical license. The WIG ship pilot's license system was first introduced by Korea, so there are no international standards for the license system, and the introduction of a domestic qualification system also requires institutional arrangements due to various restrictions such as pilot training. However, in order to become a valuable industry as a future growth engine for the ocean, several urgent problems need to be solved, and that is the training of manpower for WIG ships. Therefore, I reviewed the institutional issues related to pilot training as this subject. Since 2001, various countries around the world have been discussing this issue, centering on IMO, and Korea has continued to participate and cooperate in IMO meetings. And the national qualification test for surface flying ships was conducted in Korea from 2011. However, there are still problems to be solved, and I pointed out the advancement of the manpower training system, the education and training system, and the designated national educational institution system. As a solution to this, it was suggested through the improvement of the license system and the operation of designated educational institutions. Among these solutions, I believe that the best way is to entrust the operation of designated national educational institutions to private educational institutions. However, I propose a plan that the government entrusts to private educational institutions, but the government is responsible for licensing and supervision. WIG ship will be a new market for the aviation industry and aviation workers.