• Korean Chemical Engineering Research
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• v.51 no.5
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• pp.545-549
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• 2013

For the purpose of development of effective synthetic process of CHMI, a series of experiments were preformed on the preparation of CHMAIE, the intermediate of CHMI. For the first step, CHMA was synthesized by dropwise mixing of cyclohexylamine with maleic anhydride in toluene and 98.2% of theoretical CHMA was obtained by precipitation at $10^{\circ}C$ for 2 hours. The optimum reaction temperature of the esterfication, preparation reaction of CHAMIE from CHMA, was $68^{\circ}C$, and equilibrium conversion at optimum temperature was 98.5%. Equilibrium reaction time decreased with reaction temperature, and 4 hours was taken to reach equilibrium at optimum reaction temperature. Toluene in the final reaction product could be recovered by vacuum distillation. The recovery of toluene was increased with distillation temperature and 98% of toluene could be recovered at $55^{\circ}C$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.11B
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• pp.700-708
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• 2007

This paper considers an incentive regulation in the telecommunications industry with respect to the sale of retail and access services. This regulation scheme induces the monopoly carrier who owns bottleneck facilities to adopt socially optimal outcomes when providing access and retail services. It is well known that upstream carriers can realize an integrated level of profit, without integration, by means of a two-part tariff. First, this paper introduces a framework for regulating an access and retail price combined with budget balancing. Second, this paper introduces two-part tariff (price discrimination) scheme for both access (upstream) and retail (downstream) services and discusses the resulting implications for incentive regulation when the regulator has incomplete information about cost functions. By imposing a self-selection mechanism, the regulator can induce firms to adopt socially optimal prices in both access and retail markets.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.4
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• pp.41-49
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• 2007

This study aims to examine the ripple effect of the '119 Integrated Information System' for city disaster management on the local economy. The study was conducted in the area of Gyeongnam province, and the study method is the interdependence analysis based on the Input Coefficient drawn from Input-Output Tables in which Intermediary Transaction Tables drawn through RAS was taken advantage of to grasp the correlation among industries and regions in terms of the local economy, and the ripple effect of the changes of political exogenous variables on the local economy was divided to such elements as production, added value, and employment so as to attempt empirical analysis on the local economy system. To estimate the ripple effect on the local economy, three different amounts of the expected input were applied to the study respectively and the results are as follows: Some $28.7{\sim}42.4$ billion won for the production induction effect, some $7.5{\sim}11.4$ billion won for the added-value induction effect, some $103{\sim}157$ job openings for the employment induction effect, and some $3.8{\sim}5.7$ billion won for the income induction effect are expected to take place as the ripple effect on the local economy.

• Environmental and Resource Economics Review
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• v.31 no.4
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• pp.669-691
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• 2022

In this analysis, from the perspective of the business ecosystem, the economic effects of the oil and gas E&P industry were estimated. Australia, Norway, and the US, which are countries that are active in oil and gas E&P projects, and Japan and Korea, which are not, were analyzed. According to the analysis results, every country has a induced production coefficient of the oil and gas E&P industry greater than 1. Norway and the US have formed an industrial ecosystem across all industries, evenly demanding intermediate inputs for the primary, secondary, and tertiary industries. In contrast, Korea and Japan have a very large input ratio from the tertiary industry and an industrial ecosystem centered on the tertiary industry. It should be considered that the high input ratio of certain industry in business ecosystem determine the scale of the induced effect. When the business ecosystem are formed with many industries evenly, and the induced coefficient is high, it is necessary to increase the amount of final demand of the industry to make the effects of coefficient to increase.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.76-79
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• 2005

대수층 폭기법(aquifer air sparging)은 대수층에 가압공기를 주입하여 휘발성 유기오염물질을 제거하는 지반환경복원 기술의 하나이다. 본 연구는 전통적인 지하 대수층 폭기기술 시행에 있어서 특정층에 미리 수용액상 계면활성제를 수평방향으로 도입함으로써 오염물질이 실제로 존재하는 층에 선택적으로 폭기 되도록 하여 최소한의 공기량으로 제거 효율을 극대화 하는 기술을 개발하는 것을 목적으로 한다. 본 연구에서는 균일질 모래로 충진된 2차원 상자 모델을 사용하였으며, 표면장력 조절을 위하여 저농도(100mg/L) 음이온계 계면활성제(sodium dodecyl benzene sulfonate) 수용액이 사용되었다. 실험은 계면활성제가 처방되지 않은 경우, 공기도입부 근처에 계면활성제 용액이 도입된 경우, 공기도입부와 토양표면의 중간부분에 계면활성제 용액이 도입된 경우의 세 가지 방법으로 실시되었다. 실험 결과, 계면활성제가 도입된 경우는 투입되지 않은 경우에 비하여 최고 5배에 해당하는 폭기영향권의 확대가 관찰되었으며 폭기영향권이 계면활성제가 도입된 수평층을 중심으로 형성되어 이 부분에 집중되어 존재하는 오염물질의 제거에 매우 유리할 수 있다는 점이다. 대수층 도입공기의 수평확산을 유도하는 기술로 본 연구는 기존의 대수층 폭기 복원기술의 효율을 획기적으로 개선할 수 있을 것으로 기대된다.

• The Journal of the Korea Contents Association
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• v.16 no.1
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• pp.1-12
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• 2016

The purpose of this study was to identify latent classes of socioeconomic status and to explore whether those of socioeconomic status influenced self-esteem among elderly living alone. From the data of 2009 National Elder Abuse Investigation, 1,333 older adults who were over 65 years and living alone were analyzed. Latent class analysis, one-way ANOVA, and hierarchical regression analysis were performed to test the purpose of this study. Results of this study found 5 latent classes of socioeconomic status, named as high education-low income group, low education-low income group, middle education-low income group, high education-high income group, and low education-high income group. Next, there were significant differences in self-esteem depending on 5 latent classes of socioeconomic status. Finally, compared to low education-low income group, high education-low income group, middle education-low income group, high education-high income group, and low education-high income group showed higher levels of self-esteem, even after adjusting for confounding factors. Findings from this study suggested fundamental characteristics and public policy for elderly living alone.

• Journal of the Korean earth science society
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• v.30 no.2
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• pp.257-264
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• 2009

The purpose of this study was to examine the effects of the game application learning 8th graders' scientific attitude, which was utilized as a strategy to improve the teaching skills and methods in the lesson of 'the history of the earth and diastrophism'. The subjects of this study were 120 students of 8th grade at a middle school located in a metropolitan city in Korea. To start off with homogeneity of a group, this study recruited participants by the results of a diagnostic test taken early in the year and a mid-term examination taken at the end of April. As a result, a total of 4 male classes that showed similar results on the two tests were selected and divided into two groups: one in experimental and the other in control. In addition, the top 20% students and the low 20% students were chosen for comparison of their scientific attitudes based on the results of the mid-term examination. The traditional teachings were offered to the control groups while the experimental lessons with the game activities performed at the stages of application and summary in teaching were offered to the experimental groups over 10 periods. Results of the pre- and post-test on the students' scientific attitude demonstrated that there was a statistical significance between the two groups, which suggested that the experimental group showed a meaningful improvement in the scientific attitude after experimental intervention lesson activities with game applications. Also, the more meaningful improvement in the scientific attitude was found in the lower group than in the higher group. It implies that lessons with the game activities motivated the students to voluntarily participate in school science learning by enhancing their interests. Therefore, it is suggested that game application learning be a new teaching-learning material that helps to encourage learners to actively participate in middle school science learning.

• Korea Real Estate Review
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• v.27 no.4
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• pp.51-61
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• 2017

The purpose of this study is to find out the implications for the activation of the real estate industry by comparing the structure of production and distribution, as well as the industrial linkage, of Korean real estate industry with that of the US through an input-output analysis. This study employed the World Input-Output Database (WIOD) provided by the EU in 2016. The results are as follows. First, while the share of the Korean real estate industry in the national economy has been steadily decreasing since the year 2000, the real estate industry of the United States is increasing. Second, both Korean and US real estate businesses have higher value added rates than the industry average, but the intermediate demand rate is lower than the industry average. Furthermore, the intermediate input rate and intermediate demand rate of the Korean real estate industry were lower than that of the US. Third, the change in the final demand for the Korean real estate industry has a lower production and value added effect on the national economy than that of the United States. Fourth, the industrial linkage of the US real estate industry is larger and broader than that of Korea. Finally, it is suggested that a policy to increase the industrial linkage of real estate industry with high value-added industries is needed in order to revitalize Korea's real estate industry.

• Journal of Animal Environmental Science
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• v.14 no.2
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• pp.129-138
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• 2008

This study was carried out to investigate the operating characteristics, water balance and chemical properties of compost during the composting with pig slurry on-farm trial. The composting plant with sawdust pile filteration was done in a forced aeration inside a house and equipped with a turning machine moving on a rails. The composting pit was 4.6m wide, 53m long and the maximum height was 2m. A field scale aerobic composting facility was tested the composting efficiency of high moisture pig slurry. The sawdust materials remained 6 months. Pig slurry was added to compost pile every other day during 6 months run. The temperature in compost pile and compost house, and input and output of moisture were measured during composting process. The result are summarized as follows; 1. The temperature of compost was varied in range of at $22.4^{\circ}C{\sim}71.1^{\circ}C$. After turning, the composting temperature decreased to $50^{\circ}C{\sim}36^{\circ}C$ during $3{\sim}5$ hours, and then raised to $64.5^{\circ}C$ 2. The temperature of compost house was maintained $20^{\circ}C{\sim}30^{\circ}C$, and relative humidity was varied in range of $50{\sim}99%$. 3. BOD, CODcr and SS of leachate water was reduced 89.5%, 81.2%, 97.5%, respectively. 4. The content of heavy metal in the final compost was lower those of Korea standards. 5. The amount of effluent was 10.2%. Total evaporation during composting Period were 74.8%. The amount of slurry per $1m^3$ sawdust was $3.16m^3$ without treatment of effluent output.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.401-407
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• 2007

This study analyzed an economic efficiency of oak mushroom cultivation in order to provide data needed for formulating related policies. 88 farmhouses in major producing areas were interviewed with. The average production cost per 100 bed-logs was 151,699 won. Among production costs, material costs accounted for 56.0% and labor costs 41.8%. Oak mushroom cultivation was labor-intensive and labor input was a significant factor determining the production costs. There was 3 7.2% gap in production costs between Chungbuk, the highest cost area and Gyeonggi, the lowest cost area of oak mushroom due to difference in labor input. Average revenue per 100 bed-logs was 178,627 won. Average income per 100 bed-logs, which is variable production costs of 116,613 won subtracted from the revenue, was 62,014 won and thus income rate was 34.7%. Income rate in Jeonbuk, the highest area, was higher than that in Gyeonggi, the lowest area, by 15.8% points due to difference in quantities produced, grade, and variable production costs, in particular, labor costs. The result of the economic analysis indicates that reduction in establishment and labor costs, accounting for the highest portion in production costs is priority issue for the enhancement of the competitiveness of the oak mushroom industry.