• Korean Journal of Environmental Agriculture
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• v.30 no.1
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• pp.24-30
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• 2011

BACKGROUND: High input to the arable land is contributed to increasing productivity with causing the global environmental problems at the same time. Rapeseed cultivation has been forced to reassess its positive point for utilization of winter fallow field. The Objective of this study was performed to assess the environmental impact of rapeseed cultivation with double-cropping system in paddy rice on Yeonggwang district using life cycle assessment technique. METHODS AND RESULTS: For assessing each stage of rapeseed cultivation, it was collected raw data for input materials as fertilizer and pesticide and energy consumption rate by analyzing the type of agricultural machinery and working hours by 1 ton rapeseed as functional unit. Environmental impacts were evaluated by using Eco-indicator 95 method for 8 impact categories. It was estimated that 216 kg $CO_2$-eq. for greenhouse gas, 3.98E-05 kg CFC-11-eq. for ozone lazer depletion, 1.78 kg SO2-eq. for acidification, 0.28 kg $PO_4$-eq. for eutrophication, 5.23E-03 kg Pb-eq. for heavy metals, 2.51E-05 kg B(a)p-eq. for carcinogens, 1.24 kg SPM-eq. for smog and 6,460 MJ LHV for energy resource are potentially emitted to produce 1 ton rapeseed during its whole cultivation period, respectively. It was considered that 90% of these potential came from chemical fertilizer. For the sensitivity analysis, by increasing the productivity of rapeseed by 1 ton per ha, potential environmental loading was reduced at 22%. CONCLUSION(s): Fertilization affected most dominantly to the environmental burden, originated from the preuse stage, i.e. fertilizer manufacturing and transporting. It should be included and assessed an indirect emission, which is not directly emitted from agricultural activities. Recycling resource in agriculture with reducing chemical fertilizer and breeding the high productive variety might be contribute to reduce the environmental loading for the rapeseed cultivation.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.559-571
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• 2017

This study was conducted to determine the adhesive performances of plywoods affected by layering direction and the amounts of thermoplastic films. The face and back layers of veneer were hardwood species (Mixed light hardwood) and core layer veneer was radiata pine (Pinus radiata D. Don). Thermoplastic film used as adhesive were polypropylene (PP) film and polyethylene (PE) film. Thermal analysis and tensile strength were investigated on each films. As a result, the melting temperature of PP and PE films were $163.4^{\circ}C$ and $109.7^{\circ}C$, respectively, and the crystallization temperature were $98.9^{\circ}C$ and $93.6^{\circ}C$, respectively. Tensile strength and elongation of each films appeared higher on the width direction than length direction. Considering the characteristics of the thermoplastic films, the test for the amount of film used was carried out by layering film to the target thickness on veneer. The effecting of layering direction of film on plywood manufacturing was conducted by laminating in the length and width directions of the film according to the grain direction of veneer. Tensile-shear strength of plywood in wet condition was satisfied with the quality standard (0.7 MPa) of KS F 3101 when the film was used over 0.05 mm of PP film and over 0.10 mm of PE film. Tensile-shear strength of plywood after cyclic boiling exceeded the KS standard when PP film was used 0.20 mm thickness. Furthermore, higher bonding strength was observed on a plywood made with width direction of film according to grain direction of veneer than that of length direction of film. Based on microscopic analysis of the surface and bonding line of plywood, interlocking between veneers by penetration of a thermoplastic film into inner and cracks were observed.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.4
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• pp.393-400
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• 2008

1,4-Dioxane($C_4H_8O_2$), which is used as a solvent stabilizer, could make harmful effects on ecosystem because of its higher solubility, toxicity and carcinogenic by US EPA. From 2011, its discharge limit to waterbody will be regulated at 5 mg/L by Ministry of Environment Republic of Korea. It was thus to investigate that the currently operating activated sludge in polyester manufacturing processes in Gumi can properly treat it to meet with the regulation standard. For that purpose, the removal rate of 1,4-dioxane and its microbial properties were assessed for a few companies(i.e. K, H and T). Its removal efficiency was the most highly recorded in H as 98% and then 77% for K, which met with the regulation standard. However, concentration of 1,4-dioxane of T was 23 mg/L in the effluent, which is more than the regulation standard. Aside from, microbial degradation test was done for 100 ppm of 1,4-dioxane in BSM (Basal salt medium) inoculated with each of activated sludge. After 7 days, 1,4-dioxane was completely removed in the test bottle inoculated with H sludge, 67% in T and 52% in K, which could confirm that the given activated sludge might have different biodegradability against the amount of 1,4-dioxane. Therefore, microbial diversity in each company was investigated by 16s rDNA cloning methods where a species, e.g. Methylibium petroleiphilum PM1, was the greatest observed from H and in lesser from K, but it was not detected from T. Methylibium petroleiphilum PM1 is known to efficiently degrade ether like methyl tertiary-butyl ether(MTBE). It is concluded that the activated sludge in H can be most effectively adopted for a biodegradation of 1,4-dioxane in the concern of industrial sector.

• Applied Biological Chemistry
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• v.45 no.1
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• pp.11-17
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• 2002

Fermentation characteristics with/without nitrogen source and quality of the fruit distillate of Opuntia ficus-indica var. saboten were investigated during the manufacturing process of a Korean traditional liquor. As the fermentation period increased, acidity, brix degree, and alcohol concentration increased, whereas pH and contents of reducing sugar decreased. Acidity, pH, and brix degree were higher, whereas the content of reducing sugar lower, in the nitrogen source-added distillate than in the distillate without nitrogen source. The growth of yeast increased, while that of bacteria decreased; this trend was more prominent with the addition of a nitrogen source. Sojues, distilled from two types of mashes and diluted with $H_2O$ and tails of distillate into 22% alcohol concentration, showed pH $3.7{\sim}4.0$, acidity $0.02{\sim}0.10$, and $5.4{\sim}6.1$ $^{\circ}Brix$. Analysis through GC using direct injection methods revealed common volatile flavor compounds in sojues, including acetaldehyde, acetyl acetone, acetic acid ethyl ester, ethyl alcohol, 2-propyl alcohol, acetone, n-propyl alcohol, butanoic acid methyl ester, 2-phenyl ethanol, thymol, acetic acid phenyl ester, and vanillic aldehyde. As revealed through the sensory evaluation, no significant difference (p>0.05) in overall acceptability was shown among four experimental groups, while color and flavor showed significant differences(p<0.05).

• Korea journal of population studies
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• v.19 no.1
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• pp.93-122
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• 1996

This is a study of the determinants of sexual, contraceptive, and abortion behavior among unmarried female adolescents and young adults, which has emerged as a growing and serious health problem in Korea. As part of a larger project, data were gathered in three export zones: Kuro (Seoul), Kumi (Kyngbuk) Masan Changwon (Kyongnam) ; and the study samples are regrouped into three categories: 1) factory workers, i.e. , the reference group serving as program participants, 2) entertainment workers, and 3) ob-gyn patients. This study indicates that entertainment workers are at highest risk of experiencing premarital sex, STDs, contraceptive failure, unwanted pregnancies, and induced abortion. Of them, 20 percent had STDs as a result of first sexual experience: and about seven tenths had two or more pregnancies due to the adoption of low-efficacy methods. The proportion of those who had ever been pregnant was 60 percent for the group as a whole: 36 percent for the program participants: 64 percent for the entertainment workers ; and 91 percent four the ob-gyn patients. These proportions are exactly the same for abortion in each group, which means that all pregnancies ended in induced abortion. Of the respondents who said that they were sexually active at the time of survey, abortions were very high: 1.6 for the program participants, 2.3 for the entertainment workers, and 1.9 for the ob-gyn patients. About 80 percent of the women had abortions during the first trimester, and two thirds of the first abortions took place between the ages of 20 and 23. About one fourth experienced post-abortion complication, which was highest among the program participants (39 percent). Sixty percent of those with complications visited a hospital or took medicine to treat the problem. Even after the experience of induced abortion, the use of contraception was very low, except among the entertainment workers, whose level of use reached 53 percent. The most obvious recommendation, arising from this research, is that 'good-quality' counselling and family planning services be established under the auspices of both national and local government, particularly targeted for the entertainment workers as well as the factory workers in various textile, electronic, manufacturing, and other industrial sectors. We believe that entertainment sectors should be restructured radically so that young women who work for amusement bars and other entertainment sectors obtain protection from the risk of having unwanted pregnancies, STDs, and induced abortion.

• The Korean Journal of Air & Space Law and Policy
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• v.20 no.2
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• pp.59-158
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• 2005

When a military aircraft suffers damages due to the defects in its design, manufacturing or notification, all of which are generally understood as products liability defects, the obvious compensation is sought as it would in other consumer good case. However, there exist clear yet unappreciated difference between general consumer goods and military aircraft, as far as products liability law is concerned - some sort of recovery should be obtained even when there exist only defects, not damages, to the aircraft because of the implication of defective parts is much grave than what can be expected in a consumer goods case. While certain anticipatory measures do exist in manual or at negotiation stages for the safety of military aircraft, such measures are ineffective, if not ambiguous, in recovery effort in the post-accident stage In another word, the standardized military procurement contract manuals and boilerplate forms do not appreciate the unique and dangerous military nature of military aircraft. There are many unique legal issues which can arise when trying to prevent defective aircraft or parts, or to recover compensations for accident due to such defects. At two-level, the government should establish legal system (or countermeasures if you'd like) for purchasing safer military aircraft. First, one should be able to work with legal ground and policy that allows selecting and purchasing safer goods - the purpose of such contract is not litigious, but rather in acquiring what are most reliable. Second, in case the defects do arise and lead to damages, solid legal principles and instructions should be established for effectively pursuing appropriate company, (usually a aerospace industry giant with much experience) for products liability - the purpose of such pursuit is inevitable for a public official, since he or she is no private business man with much flexibilities, even to the point of waiving such compensatory right for future business purposes. This article tries to identify problems in methods of procuring military aircraft or parts - after reviewing on how the military can improve on legal and policy grounds for procuring what will be the focus of future military strength, it will offer some of the ways to effectively handling and resolving a liability issues.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.46-52
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• 2009

Statement of problem: Recently, titanium has become popular as superstructure material in implant dentistry because titanium superstructure can be easily milled by means of computer-aided design and manufacture (CAD/CAM) technique. But retention form such as nail head or bead cannot be cut as a result of technical limitation of CAD/CAM milling and bond strength between titanium and porcelain is not as strong as that of conventional gold or metal alloy. Purpose: The objective of this study was to evaluate the shear bond strength of three different materials: heat curing resin, composite resin, porcelain which were bonded to grade II commercially pure Titanium (CP-Ti). Material and methods: Thirty seven CP-Ti discs with 9 mm diameter, 10 mm height were divided into three groups and were bonded with heat curing resin (Lucitone 199), indirect composite resin (Sinfony), and porcelain (Triceram) which were mounted in a former with 7 mm diameter and 1 mm height. Samples were thermocycled for 1000 cycles at between $5-55^{\circ}C$. Shear bond strength (MPa) was measured with Instron Universal Testing Machine with cross head speed of 1 mm/min. The failure pattern was observed at the fractured surface and divided into adhesive, cohesive, and combination failure. The data were analyzed by one-way ANOVA and Scheffe's multiple range test (${\alpha}=0.05$). Results: Lucitone 199 ($17.82{\pm}5.13\;MPa$) showed the highest shear bond strength, followed by Triceram ($12.97{\pm}2.11\;MPa$), and Sinfony ($6.00{\pm}1.31\;MPa$). Most of the failure patterns in Lucitone 199 and Sinfony group were adhesive failure, whereas those in Triceram group were combination failure. Conclusion: Heat curing resin formed the strongest bond to titanium which is used as a CAD/CAM milling block. But the bond strength is still low compared with the bond utilizing mechanical interlocking and there are many adhesive failures which suggest that more studies to enhance bond strength are needed.

• Journal of dental hygiene science
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• v.17 no.4
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• pp.333-340
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• 2017

The prevalence of periodontal disease was steadily increased. The best prevention methods for periodontal disease are teeth brushing and scaling. The purpose of this study was to investigate the status of scaling experience and related factors among some workers. Total 455 workers in 5 manufacturing companies in Gwangju were selected using convenience sampling method. General characteristics, work-related characteristics, oral health-related characteristics and scaling experience were collected by self-reported questionnaires. Chi-square tests, t-tests and multiple logistic regression analysis were performed to investigate the factors influencing the scaling experience using SPSS software. Statistical significance was defined as a p-value<0.05. The proportion of scaling experience during the past year was 47.0%. In simple analysis, age, current working position, number of oral disease, interest in oral health, use of secondary oral products, oral health screening use, oral health education experience and awareness of scaling inclusion in the National Health Insurance (NHI) coverage were associated with scaling experience. Finally, the odds ratios (ORs) for scaling experience were significantly higher in younger subjects (adjusted OR [aOR], 3.09; 95% confidence internal [CI], 1.60~5.96), assistant manager (aOR, 2.68; 95% CI, 1.55~4.63), subjects with high interest in oral health (aOR, 2.15; 95% CI, 1.02~4.52), subjects with oral health screening use (aOR, 2.76; 95% CI, 1.50~5.11) and awareness of scaling inclusion in the NHI coverage (aOR; 2.91, 95% CI, 1.80~4.72) in multiple logistic regression analysis. Scaling experience was relatively low (47.0%). The related factors with scaling experience were age, working position, use of screening and awareness of scaling inclusion in the NHI coverage. Considering these factors will increase the utilization rate of scaling.

• Journal of Internet Computing and Services
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• v.14 no.6
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• pp.95-105
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• 2013

Recently, SME's Collaboration activities have become one of a vital factor for sustaining competitive edge. This is because of the rapidly changing and competitive market environment, and also to leverage performance by overcoming obstacles of having limited internal resources. Discussing about the effects and relationships of the firm's collaboration activities and its outputs are not new. However, as ICT and various technologies have been diffused into the traditional industries, boundaries and practice capabilities within the industries are becoming ambiguous. Thus contents of the products/services and their development methods are also go and come over the industries. Although many researchers suggested the relations of SME's collaboration activities and innovation performances, most of the previous literatures are focusing on broad perspectives of firm's environmental factors rather than considering various SME's idiosyncrasy factors such as their major product and customer types at once. Therefore, the purpose of this paper is to analyze how SME(Small Medium Enterprise)'s external collaboration activities by their idiosyncrasy act as an input to types of innovation performance. In order to analyze collaboration effects in detail, we defined factors that can represent the SME's business environment - Perceived importance of using external resources, Perceived importance of external partnership, Collaboration and Collaboration levels of Major Product types, Customer types and lastly the Firm Sizes. We have also specifically divided the performance of innovation types as product innovation and process innovation based on existing research. In this study, the empirical analysis is based on Probit Regression Model to observe the correlations with the impact of each SME's business environment and their activities. For the empirical data, 497 samples were collected which, this sample data was extracted from the 'Korean Open Innovation Survey' performed by ETRI(Korean Electronics Telecommunications Research Institute) in 2010. As a result, empirical test results indicated that the impact of collaboration varies depend on the innovation types (Product and Process Innovation). The Impact of the collaboration level for the product innovation tend to be more effective when SMEs are developing for a final product, targeting on for individual customers (B2C). But on the other hand, the analysis result of the Process innovation tend to be higher than the product innovation, when SMEs are developing raw materials for their partners or to other firms targeting on for manufacturing industries(B2B). Also perceived importance of using external resources has effected to both product and process innovation performance. But Perceived importance of external partnership was statistically insignificant. Interesting finding was that the service product has negative effects on for the process innovation performance. And Relationship between size of the firms and their external collaboration activities with their performance of the innovations indicated that the bigger firms(over 100 of employees) tend to have better for both product and process innovations. Finally, implications of the results can be suggested as performance of innovation can be varied depends on firm's unique business idiosyncrasy as well as levels of external collaboration activities. The Implication of this research can be considered for firms in selecting an appropriate strategy as well as for policy makers.

• 대한공업교육학회지
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• v.38 no.2
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• pp.267-286
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• 2013

Recently, the advanced company has been sparing no efforts in improving necessary core knowledge and technology to achieve outstanding work performance. In this rapidly changing knowledge-based society, the company has confronted the task of creating a high value-added knowledge. The role of R&D workforce that corresponds to the characteristic and role of knowledge worker is getting more significant. As the life cycle of technical knowledge and skill shortens, in every industry, the technical knowledge and skill have become essential elements for successful business. It is difficult to improve competitiveness of the company without enhancing the competency of individual and organization. As the competency development which is a part of human resource management in the company is being spread now, it is required to focus on the research of determining necessary competency and to analyze the competency of a core organization in the research institute. 'H' is the semiconductor manufacturing company which has a affiliated research institute with its own R&D engineers. Based on focus group interview and job analysis data, vision and necessary competency were confirmed. And to confirm whether the required competency by job is different or not, analysis was performed by dividing members into workers who are in charge of circuit design and design before process development and who are in the process actualization and process development. Also, this research included members' importance awareness of the determined competency. The interview and job analysis were integrated and analyzed after arranging by groups and contents and the analyzed results were resorted after comparative analysis with a competency dictionary of Spencer & Spencer and competency models which are developed from the advanced research. Derived main competencies are: challenge, responsibility, and prediction/responsiveness, planning a new business, achievement -oriented, training, cooperation, self-development, analytic thinking, scheduling, motivation, communication, commercialization of technology, information gathering, professionalism on the job, and professionalism outside of work. The highly required competency for both jobs was 'Professionalism'. 'Attitude', 'Performance Management', 'Teamwork' for workers in charge of circuit design and 'Challenge', 'Training', 'Professionalism on the job' and 'Communication' were recognized to be required competency for those who are in charge of process actualization and process development. With above results, this research has determined the necessary competency that the 'H' company's affiliated research institute needs and found the difference of required competency by job. Also, it has suggested more enthusiastic education methods or various kinds of education by confirming the importance awareness of competency and individual's level of awareness about the competency.