• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.2
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• pp.62-70
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• 2010

A feasibility test for accelerating composting of sewage sludge irradiated with electron beam(3kGy) was investigated. Dried wood chip and leaves were used as a bulking agent and carbon source, respectively. The test variables included changes in temperature, organics and nutrients, and bioactivities from experimental and control composters. Results indicates that the temperature rose up to $60^{\circ}C$ within 1 day and maintained high temperature above $50^{\circ}C$ for more than 5 days in the irradiated sludge cake composter. It resulted in the fast degradation of organics during the initial 5 days, showing that approximately 70% of total amount of carbon degraded within 20 days was destroyed. It is likely that the composting of electron beam irradiated sludge cake is able to reduce it's maturing period significantly.

• Economic and Environmental Geology
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• v.39 no.6 s.181
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• pp.699-710
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• 2006

Batch scale experiments to investigate the efficiency of the solidification process for metal mine tailing treatment were performed. Portland and MSG (micro silica pouting) cements were used as solidifier and three kinds of mine tailings (located at Gishi, Daeryang, and Aujeon mine) were mixed with cements to paste solidified matrices. Single axis com-pressible strengths of solidified matrices were measured and their heavy metal extraction ratios were calculated to investigate the solidification efficiency of solidified matrices created in experiments. Solidified matrices ($5cm{\times}5cm{\times}5cm$) were molded from the paste of tailing and cements at various conditions such as different tailing/cement ratio, cement/water ratio, and different cement or tailing types. Compressible strengths of solidified matrices after 7, 14, and 28 day cementation were measured and their strengths ranged from 1 to $2kgf/mm^2$, which were higher than Korean limit of compressible strength for the inside wall of the isolated landfill facility ($0.21kgf/mm^2$). Heavy metal extractions from intact tailings and powdered matrices by using the weak acidic solution were performed. As concentration of extraction solution for the powdered solidified matrix (Portland cement + Gishi tailing at 1:1 w.t. ratio) decreased down to 9.7 mg/L, which was one fifth of As extraction concentration for intact Gishi tailings. Pb extraction concentration of the solidified matrix also decreased to lower than one fourth of intact tailing extraction concentration. Heavy metal extraction batch experiments by using various pH conditions of solution were also performed to investigate the solidification efficiency reducing heavy metal extraction rate from the solidified matrix. With pH 1 and 13 of solution, Zn and Pb concentration of solution were over the groundwater tolerance limit, but at pH $1{\sim}13$ of solution, heavy metal concentrations dramatically decreased and were lower than the groundwater tolerance limit. While the solidified matrix was immerged Into very acidic or basic solution (pH 1 and 13), pH of solution changed to $9{\sim}10$ because of the buffering effect of the matrix. It was suggested that the continuous extraction of heavy metals from the solidified matrix is limited even in the extremely high or low pH of contact water. Results of experiments suggested that the solidification process by using Portland and MSG cements has a great possibility to treat heavy metal contaminated mine tailing.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.1
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• pp.153-180
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• 2020

This study is meaningful in finding out what legal and policy issues need to be improved in order to foster the aircraft industry, which is relatively underdeveloped compared to the fact that some heavy industries, such as the automobile industry and shipbuilding industry, have achieved a high level of production and technology globally. Korea's aircraft industry has been growing at a slower pace than other industries, largely due to the country's economic growth and the lack of a market structure to properly use variables such as the level of development in related industries, aircraft technology and demand for aircraft manufacturing. While most industries are privately led by the market structure of the competition system, heavy industries such as the aircraft industry generally grow under the market structure of the incomplete competition system, because only by securing huge initial investment costs, high technology, and sufficient demand, they can maintain minimum economic feasibility. The Korean aircraft industry was focused on developing and mass-producing military aircraft focusing on military demand, but it sought to turn the tide by signing the BASA (Bileral Aviation Safety Agreement) with the U.S. A preliminary feasibility study was conducted in 2010 to develop next-generation medium-sized aircraft, but was cancelled due to differences in position with Canada's Bombardier, which is subject to the concourse, and Korea Aerospace Industries (KAI) is pushing for the production of Bombardier's Q400 license on its own. Compared to the mid-to-large sized civil aircraft that are facing difficulties in development, KAI and KARI are successfully developing technologies to unmanned aerial vehicles and civil helicopters. In addition, the unmanned aerial vehicle sector is not yet suitable for manufacturers that have an exclusive global influence, so we believe that it is necessary to pursue government-led research and development projects with a focus on the areas of commercial helicopters and unmanned aerial vehicles in order to foster the aircraft industry in the future. In addition, since military aircraft such as KT-1 and T-50 are currently being exported smoothly, and it cannot be overlooked that the biggest demand for aircraft manufacturing in the Korea is the military, it is necessary to push forward national R&D projects and defense R&D program simultaneously to enable both civilian-military development. However, there are many differences between the two projects in the way they are implemented, the department in charge and the royalty system. Through this study, we learned about the technology ownership and implementation rights of national R&D projects and defense R&D programs, as well as the royalty system. In addition, problems with the system were identified and improvement measures were derived.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.1
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• pp.29-37
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• 2008

This study examined principles and techniques of efficient water quality management as well as total coastal pollutant loads and the relevant examples in the advanced countries from the viewpoints of water quality improvement and pollution control in coastal areas. The problems and improvements in an estimation of the current total pollutant loads were also pointed out. In addition, discussion was made on the relationship between total pollutant loads and environmental capacity as well as particulars requiring extensive examination on access to and study on water quality model used as prediction tool for marine environment. Furthermore, this study proposed details of and improvement plans for water quality control to be reflected and absorbed into systems and policies related to coastal water quality. In coastal areas, which are subject to total coastal pollutant loads, it is necessary to calculate pollutant loads reduction and allocation, to propose them in detail in statement in relations to new pollution sources for the corresponding projects or plans in environmental impact assessment and prior environmental review system. Also, in relations to regional plans for coastal management, the local government concerned must focus more on environmental management plan to implement data on pollution sources and pollutant loads flown into sea areas under basic jurisdiction, therefore it is required to actively respond to expansion and introduction of total coastal pollutant loads system in the future. Total coastal pollutant loads system must be expanded and executed by considering characteristics of sea area and changes in the environment of land. For pollution sources in land, the competent authorities in charge of coastal environment will need to initiatively administer supervision, monitoring activities and achieve integration and operation of the related laws by preparing legal bases for management system or adjusting the related laws.

• Journal of Distribution Research
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• v.15 no.5
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• pp.103-126
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• 2010

The development of an industry including distribution sector is influenced by not only government policy but the related firms' behaviors. Recently the large-scale retailers have had more enormous channel power than any other distributors including monopolistic makers. Now is the time for government to prepare some policies against the unfair transaction behaviors by large-scale retailers. In this paper I tried to inquire into the distribution competition policy from a political correspondent point of view related with the transition of distribution system. For the purpose of this article I compared the case of Korea with Japan. According to the results so far inquired, there are some commons and differences in the cases of the two. Some suggestions are as follows. Considering the predominant position the concept of large-scale retailers is to be extended from a single store to numerous chain stores in the political level. Government needs to examine the standard propriety for large-scale retailer; the size of selling area and amount of sales a year. When a large-scale retailer store is to be established, it need to be taken a permit or a pre-inspection. The Fair Trade Commission have to secure the neutrality from Government's strategies. And government should find out the examples of unfair transaction behavior types and prepare some proper guidelines continually. For the last time statistical data by distributors are to be fitted out and the actual investigations for estimating the effects of government policies need to be enforced.

• 한국노년학
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• v.37 no.1
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• pp.55-82
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• 2017

The purpose of this research is to provide implications for the development of age-friendly industry of Korea by analyzing the age-friendly industry activation policy suggested by the Presidential Committee on Ageing Society and Population Policy in response to the population ageing problems. Policy and theoretical implications are derived from an analysis of age-friendly industry activation policy as directly related to the improvement of the three major problems (i.e. health, economy, and loneliness) of Korean older people. This analysis focuses on its specific content, common and core logic, and the validity of the logic. The results show that: 1)the first Plan for Ageing Society and Population suggests a policy for improving poverty, 2)the second Plan for Ageing Society and Population suggests a policy for improving health, and 3)the third Plan for Ageing Society and Population suggests a policy for improving health and loneliness. All policies not only are commonly based on the logically limited concepts of successful ageing and active ageing, but also are characterized by narrow realm, insufficient content, and fragmented policy. The results result in the following policy implications: 1)the age-friendly industry activation policy should be developed with continuity, sufficiency, and diversity, 2)lessons from the limitation related with the de-contextualisation of successful ageing and its elective affinity with consumer capitalism, 3)lessons from the prevention-oriented perspective of active ageing, and 4)lessons from the social characteristics of (non-)psychological resources, limitation of the reablement related with social investment state. The analyses also provide a theoretical implication that a different perspective on the social construct of ageing is needed beyond the dichotomy of ageing based on modelling ageing. Lastly, the paper suggests not only the limitation of the research but also the preferred follow-up studies regarding age-friendly industry activation policy.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.430-437
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• 2007

The probability table of Moyers and prediction equation of Tanaka and Johnston that have been the most frequently used, cannot produce accurate prediction when used in Korean because they are based on the Caucasian popularity of the Northern European race. The method of Moyers or Tanaka and Johnston predicts sizes of the unerupted canine and premolars on the basis of the sizes of mandibular incisors. However, some of the recent papers raise a question as to whether the mandibular incisors are the best combination to predict the sizes of the unerupted canine and premolars. The purpose of this study is to determine which sum or combination of sums of permanent tooth widths present the best prediction for the unerupted canine and premolars in a Korean sample, to calculate a specific linear regression equation for this population, and to evaluate the clinical significance. A new linear regression equation was calculated based on the data of 178 Korean young adults(70 women, 108 men, mean age 21.63 years) with complete permanent dentitions. Fifty three more children(28 girls, 25 boys, mean age 14.22 years) were used as a validation sample for the application of the multiple linear regression equation. The conclusions were as follows: 1. The combination of the sums of permanent upper central incisors, lower lateral incisors and upper first molars was the best predictor for the unerupted canine and premolars in this sample($r=0.65{\sim}0.80$). 2. The multiple linear regression equation was calculated including sex and arch as additional predictor variables. male, upper: $Y\;=\;0.332{\times}X_0\;+\;6.195$ male, lower: $Y\;=\;0.332{\times}X_0\;+\;5.269$ female, upper: $Y\;=\;0.332{\times}X_0\;+\;5.929$ female, lower: $Y\;=\;0.332{\times}X_0\;+\;5.003$. The determination coefficient of the equation was 64% and a standard error of the estimate was 0.71mm. 3. In about 97% of the validation sample, the estimation of the tooth width sums of unerupted canine and premolars using the new multiple linear regression equation was smaller than 1mm compaired with the actual values.

• Journal of dental hygiene science
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• v.13 no.3
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• pp.254-263
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• 2013

This study is to develop an evaluation index for infection control and to verify its validity by examining each set of weighted data collected from 121 infection control personnel at dental hospitals who agreed to the preliminary survey and advisory. The study was conducted from 14th December, 2010 to 31st January, 2011, and PASW Statistics 18.0 and AMOS 5.0 had been used for the statistical data analysis. As a result of the study, five evaluation factors with 21 sub-indicators have been identified at structural level, eight evaluation factors with 32 sub-indicators at processing level, and one evaluation fact with five sub-indicators at resulting level, total 14 evaluation factors with 58 sub-indicators throughout all levels. The path analysis added on the result that 'standard precautions ($x_1$)', 'infection control support system ($x_2$)', 'internal and external characteristics ($x_3$)' are exogenous variables that affect on other variables, and 'standard infection control ($y_1$)','Organization equipment management handwashing ($y_2$)', 'environmental infection control ($y_3$), 'personal protective equipment ($y_4$)', 'waste and laundry management ($y_5$)' are endogenous variables that are infulenced by others. The standardized metrics are more needed than anything else when examining on infection control. This study attempts to develop proper dental infection control metrics adequately adjusted for domestic circumstances, and therefore to contribute to effective systematic management and decision-making in infection control.

• 대한공업교육학회지
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• v.39 no.1
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• pp.164-188
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• 2014

The purpose of this study is to investigate the perception of undergraduates of the college of education on the importance of certification areas and factors suggested by the certification system at each department level as well as the college as a whole, in order to come up with measures for further improvement. The specific objectives of this study are first, verifying different perception on the importance of certification areas and factor per department, second, verifying different perception on the importance of certification areas and factor per grade. The population of this study is undergraduates of the college of education at A University, and the survey on the different perception on the importance was conducted on 758 students of 10 departments. Total 800 copies of survey were distributed, and 299 copies or 37.3% were retrieved. First, it was found that undergraduates of the college of education at A University highly recognize the necessity of a new system to produce excellent teachers. when it comes to different department, in the area of teaching personalities, there is difference in the importance of teaching aptitude test and completion of social intelligence development program. In the area of teaching expertise, there is different perception in the importance of completion of curriculum education subjects per major, completion of curriculum contents per major, and participation in teaching demonstration contest. In the area of student guidance expertise, there is difference by department in completion of creative character development related education programs and "teaching practice" course. In the area of communication skills in the information society, minimum score requirement for a second foreign language is considered less important than others. Second, as for grade, freshmen highly recognize the importance of validity of teaching training course, integrity of the course, validity of the teaching training course in producing excellent teachers, graduates' job performing ability development as a teacher, appropriacy of curriculum of the college of education in producing excellent teachers, compared to other grades. In particular, seniors consider the necessity of a new system to produce excellent teachers the most.

• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.117-124
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• 2008

Environment-indifferent developments have brought about a great deal of environmental pollution and a destruction of the ecosystem. The global interest in environmental pollution has emerged in accordance with the environmental regulations becoming ever stricter in the international society. Various attempts are being pitched in Korea such as the PERS (Prior Environmental Review System) and EIA (Environmental Impact Assessment) and they practice a significant impact on the construction industry. Recently, there have been cases where large-scale national development businesses are delayed and terminated or re-examined for their feasibility for not having reflected and analyzed the environmental factors of the natural and ecological environment. We must sustain the ecological functions and balance and minimize environmental pollution issues that can be caused by land developments and preserve the natural environment so to induce environmentally-friendly development businesses. Thus, this research paper proposes environmental review categories of the natural ecosystem sector that can be applied to all stages of construction businesses including master planning stages, basic planning and execution designing stage, construction stage, and maintenance stage. The environmental review categories proposed in this paper are expected to offer a great deal of support in terms of inducing environment-sustainable development to decision makers in the master plan stage, designers in the basic planning and execution designing stage, and construction managers in the construction and maintenance stages.