• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.650-658
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• 2006

The recycling of TDA from solid waste of TDI plant(TDI-R) by near-critical hydrolysis reaction had been studied by means of a statistical design of experiment. The main and interaction effects of process variables had been defined from the experiments in a batch reactor and the correlation equation with process variables for TDA yield had been obtained from the experiments in a continuous pilot plant. It was confirmed that the effects of reaction temperature, catalyst type and concentration, and the weight ratio of water to TDI-R(WR) on TDA yield were significant. TDA yield decreased with increases in reaction temperature and catalyst concentration, and increased with an increase in WR. As a catalyst, NaOH was more effective than $Na_2CO_3$ for TDA yield. The interaction effects between catalyst concentration and temperature, WR and temperature, catalyst type and reaction time on TDA yield had been defined as significant. Although the effect of catalyst concentration on TDA yield at $300^{\circ}C$ as subcritical water was insignificant, the TDA yield decreased with increasing catalyst concentration at $400^{\circ}C$ as supercritical water. On the other hand, the yield increased with an increase in WR at $300^{\circ}C$ but showed negligible effect with WR at $400^{\circ}C$. The optimization of process variables for TDA yield has been explored with a pilot plant for scale-up. The catalyst concentration and WR were selected as process variables with respect to economic feasibility and efficiency. The effects of process variables on TDA yield had been explored by means of central composite design. The TDA yield increased with an increase in catalyst concentration. It showed maximum value at below 2.5 of WR and then decreased with an increase in WR. However, the ratio at which the TDA yield showed a maximum value increased with increasing catalyst concentration. The correlation equation of a quadratic model with catalyst concentration and WR had been obtained by the regression analysis of experimental results in a pilot plant.

• Journal of Intelligence and Information Systems
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• v.26 no.4
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• pp.149-171
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• 2020

The period at university is to make decision about getting an actual job. As our society develops rapidly and highly, jobs are diversified, subdivided, and specialized, and students' job preparation period is also getting longer and longer. This study analyzed the log data of college students to see how the various activities that college students experience inside and outside of school might have influences on employment. For this experiment, students' various activities were systematically classified, recorded as an activity data and were divided into six core competencies (Job reinforcement competency, Leadership & teamwork competency, Globalization competency, Organizational commitment competency, Job exploration competency, and Autonomous implementation competency). The effect of the six competency levels on the employment status (employed group, unemployed group) was analyzed. As a result of the analysis, it was confirmed that the difference in level between the employed group and the unemployed group was significant for all of the six competencies, so it was possible to infer that the activities at the school are significant for employment. Next, in order to analyze the impact of the six competencies on the qualitative performance of employment, we had ANOVA analysis after dividing the each competency level into 2 groups (low and high group), and creating 6 groups by the range of first annual salary. Students with high levels of globalization capability, job search capability, and autonomous implementation capability were also found to belong to a higher annual salary group. The theoretical contributions of this study are as follows. First, it connects the competencies that can be extracted from the school experience with the competencies in the Human Resource Management field and adds job search competencies and autonomous implementation competencies which are required for university students to have their own successful career & life. Second, we have conducted this analysis with the competency data measured form actual activity and result data collected from the interview and research. Third, it analyzed not only quantitative performance (employment rate) but also qualitative performance (annual salary level). The practical use of this study is as follows. First, it can be a guide when establishing career development plans for college students. It is necessary to prepare for a job that can express one's strengths based on an analysis of the world of work and job, rather than having a no-strategy, unbalanced, or accumulating excessive specifications competition. Second, the person in charge of experience design for college students, at an organizations such as schools, businesses, local governments, and governments, can refer to the six competencies suggested in this study to for the user-useful experiences design that may motivate more participation. By doing so, one event may bring mutual benefits for both event designers and students. Third, in the era of digital transformation, the government's policy manager who envisions the balanced development of the country can make a policy in the direction of achieving the curiosity and energy of college students together with the balanced development of the country. A lot of manpower is required to start up novel platform services that have not existed before or to digitize existing analog products, services and corporate culture. The activities of current digital-generation-college-students are not only catalysts in all industries, but also for very benefit and necessary for college students by themselves for their own successful career development.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.2
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• pp.185-191
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• 2005

An experiment was conducted to study the effect of feeding ammoniated wheat straw treated with HCl on blood biochemical profiles in growing male buffalo (Bubalus bubalis) calves. Twenty-four growing male buffalo calves (one year of age, 88.54${\pm}$3.81 kg average body weight) were divided into three groups in a completely randomized design on the basis of their body weight. Animals in all the three groups were fed on concentrate mixture. In addition, they were offered wheat straw, ammoniated wheat straw (4% urea at 50% moisture level) and HCI treated ammoniated wheat straw (4% urea at 50% moisture level and HCl added to trap 30% of the NH3 evolved) in groups I, II and III, respectively for a period of 180 days, as per Kearl (1982) for body weight gain of 500 g/d. In all diets, concentrate:roughage ratio was fixed at 50:50 and were made isonitrogenous by adjusting CP levels of conc. mixtures. Blood was collected from jugular vein of each buffalo calf at the beginning and subsequently at two months interval of experimental feeding. Due to urea-ammoniation, the CP content of wheat straw increased from 2.90 to 6.96% and addition of HCl along with urea further increased the CP content to 10.09%. In all the three groups, the mean values of plasma glucose (mg %) and serum globulin (g %), showed a decreasing trend, while the mean value of serum TP (g %), serum A:G ratio, serum urea (mg %), serum creatinine (mg %), serum ALP (KA units), SGOT (units/ml.), SGPT (units/ml), serum T$_3$ and T$_4$ (ng/ml) showed an increasing trend with the advancement of feeding period. The cumulative period mean values of serum TP (6.15 to 6.20 g %), serum albumin (3.07 to 3.18, g %), serum globulin (2.98 to 3.09, g %), serum A:G ratio (1.03 to 1.10), serum ALP (23.15 to 23.63, KA units), serum T$_3$ (1.20 to 1.23 ng/ml) and serum T$_4$ (21.33 to 21.88 ng/ml) were comparable among the groups. The cumulative period mean plasma glucose (mg %) in group III (57.28) was similar to groups I (55.31) and II (59.41), however, the cumulative period mean plasma glucose in group II was significantly (p<0.01) higher than group I. The cumulative period mean serum urea (mg %) in group III (47.34) was significantly (p<0.001) higher than group I (38.38) and II (42.24), which were statistically alike. However, the cumulative period mean serum creatinine values (mg %) in groups II (1.43) and III (1.52) were similar and were significantly (p<0.01) higher than group I (1.24). The cumulative period mean SGOT (units/ml) in groups I, II and III was 91.71, 96.04 and 96.64, respectively. Similarly the cumulative period mean SGPT (units/ml) was 19.00, 19.93 and 20.01 in groups I, II and III, respectively. The cumulative period mean values of SGOT (p<0.05) and SGPT (p<0.001) in groups II and III were similar and were significantly higher than group I. The cumulative period mean serum T$_3$ and T$_4$ values in groups I (1.21 and 21.81), II (1.23 and 21.42) and III (1.20 and 21.33) were comparable. From the present study it may be concluded that feeding of AWS treated with and without HCI to growing male buffalo calves for 180 days had no significant adverse effect on blood biochemical profile.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.5
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• pp.98-108
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• 2009

The purpose of this study is to analyze the characteristics of limited methods, economics and breeding appropriateness of native and imported ground cover plants in the methodology of a shallow soil rooftop garden. The new shallow soil rooftop gardening method uses a total of 13cm in soil thickness, including 4.5cm of top soil on a 7.5cm rock-wool-mat stacked onto a 1cm roll-type-draining plate. The total construction cost for each method of soil level within the design price standard for SEDUM BLOCK is 89,433won/$m^2$, and for DAKU is 92,550won/$m^2$. By comparing those two methods, the construction cost of the shallow soil artificial foundation methodology is 45,000won/$m^2$; this shows the new method is 50% less expensive than the existing method of shallow soil rooftop gardening. The experiment was executed on the rooftop of the Korean National Housing Corporation to ensure validity of the shallow soil artificial foundation planting, and the sample plants which were imported and grown now in native covering. A list investigating the growing plants was made of the cover rate in each plant class, both while alive and the dry plant weight. The native ground cover plants, Sedum kamtschaticum, Sedum middendorffianum, Allium senescens, Sedum sarmentosum, Aquilegia buergariana, and Caryopteris incana increased the cover rate, live weight and dry weight in the shallow soil artificial foundation method. Among the imported cover plants, Sedum sprium and Sedum reflexum, the cover rate increased and growth conditions improved. However, some species needed weed maintenance. After examination with the less expensive shallow soil artificial foundation method and growth analysis, it was found that rooftop gardens are a low-cost option and the growth of plants is great. This result shows the new method can contribute to the proliferation of rooftop gardens in urban settings.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.121-131
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• 2004

Removal efficiencies of soil washing and soil improvement processes to remediate farmland soils and stream deposits around Goro abandoned mine were investigated with batch and column experiments. For As-contaminated farm-land soils around Goro mine, batch tests to quantify As extraction rate from contaminated soils and lime treated contaminated soils were performed. The contaminated soil mixed with lime decreased As extraction rate less than one fourth, suggesting that the soil improvement method mixed with lime dramatically decrease As extraction rate. A storage dam will be constructed in the lower part of the main stream connected to Goro abandoned mine and the amount of As extracted from the bottom soils of reservoir could be the main source to contaminate water of reservoir. The decrease of As extraction amount from the bottom in reservoir, caused by the application of the soil improvement method was investigated from the physically simulated column experiment and results showed that As extraction rate decreased to one forty when 1％ lime mixed soil improvement was applied to contaminated soils. For contaminated stream deposits connected Goro mine, the removal efficiency of the soil washing method was investigated with batch experiments. Hydrochloric acid, citric acid, acetic acid and distilled water were used as soil washing solution and 0.01, 0.05, 0.1, 0.5, 1.0 N of washing solution were applied to extract As. When washing with 0.05 N of hydrochloric acid or citric acid, more than 99.9% of As was removed from stream deposits, suggesting that As contaminated stream deposits around Goro mine be successfully remediated with the soil washing process. Total volumes of contaminated soils and deposits needed for remediation were calculated based on three different reme-diation target concentrations and the operation cost of soil washing for calculated soil volumes was estimated. Results from this research could be directly used to make a comprehensive countermeasure to remediate contaminated area around Goro mine and also many contaminated areas similar to this research area.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.254-263
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• 2017

This study was carried out to introduce of agronomic characteristics, forage yields and quality of Sorghum ${\times}$ Sudangrass hybrids 'Cadan 99B' and 'Sweet Sioux WMR' from 2015 to 2016 in middle and southern regions of Korea. The field experiment design was complete in seven varieties with three repetitions. Sorghum ${\times}$ Sudangrass hybrids were sown on mid-May in middle region, and end-May in southern region of Korea, in 2015 and 2016. The observed average heading date of Cadan 99B and Sweet Sioux WMR were July 22. The heading dates of Cadan 99B and Sweet Sioux WMR were 8 days earlier than SX-17 and 5 days earlier than brown mid-rid (BMR) Revolution. The sugar contents of Cadan 99B and Sweet Sioux WMR were 6.5 and $6.9Brix^{\circ}$, respectively. Comparison with BMR variety, the sugar contents of Candan 99B and Sweet Sioux WMR were 0.2 and $0.6Brix^{\circ}$ higher than Revolution, respectively. The average of dry matter (DM) yield for 2 years and 2 regions of Cadan 99B (24,587kg/ha) were the highest among the seven varieties, but there was no significant difference among other varieties except headless control variety Jumbo (19,119kg/ha) and LATTE (20,778kg/ha) (p>0.05). The crude protein (CP) and in vitro dry matter digestibility (IVDMD) of Cadan 99B were 7.5% and 60.2%, and Sweet Sioux WMR were 6.9% and 60.7%, respectively. The results of this study indicated that Sorghum ${\times}$ Sudangrass hybrids Cadan 99B and Sweet Sioux WMR are earlier heading dates and higher than SX-17, and high yields of DM in middle and southern regions of Korea.

• Journal of Animal Science and Technology
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• v.51 no.4
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• pp.295-306
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• 2009

This experiment was conducted to investigate the effects of dietary calcium (Ca) and vitamin $D_3$ metabolite on eggshell quality and hatching egg production in aged egg-type breeder hens. A total of five hundred and forty 60-week-old Hy-Line Brown breeder hens were randomly allocated to nine treatments in a $3\times3$ factorial design to determine the effects of dietary Ca levels (3.3, 3.9, and 4.5%), combined with three levels of 25-hydroxycholecalciferol [25-$(OH)D_3$ 0, 75, and $150{\mu}g/kg$], on eggshell quality and egg production for 10 weeks. There were significant Ca and 25-$(OH)D_3$ effects (P<0.01) on egg production rate. There was a linear (P<0.01) increase in eggshell strength and thickness with increasing dietary Ca and 25-$(OH)D_3$ levels. Dietary 25-$(OH)D_3$ had a significant effect (P<0.05) on hatchability of egg although fertility was not influenced by dietarylevels of Ca and 25-$(OH)D_3$. Dietary Ca levels affected Ca content in tibia (P<0.05). These results indicated that relatively high levels of dietary Ca in combination with 25-$(OH)D_3$ had a beneficial effect on improving eggshell quality and reproductive performance in aged egg-type breeder hens.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.4
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• pp.165-175
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• 2023

In venture creation research, studying 'entrepreneurial leadership' is important for uncovering and comprehending the underlying causal process in innovative behavior performance. Although previous studies provide that entrepreneurial leadership enhances followers' innovative behavior, there is few research on entrepreneurial leadership and followers' characteristics interaction. The present study's focus is paradoxical effects of entrepreneurial leadership on self-efficacy and innovative behavior. On the basis of individual regulatory focus, this study suggests that interaction effects of entrepreneurial leadership and followers' regulatory focus differed in promotion view and prevention view followers' innovative behavior. To strengthen the casual mechanism, this study conducted in priming experiment method using employees in SMEs. This study used a 2(entrepreneurial leadership vs. control) x 2 (regulatory focus: promotion vs. prevention) between-participants design. The results of this study provide that (1) Individuals in promotion focus especially benefited from entrepreneurial leadership in terms of its effect on their self-efficacy and innovative behavior; (2) whereas entrepreneurial leadership was negatively related to self-efficacy and innovative behavior of followers' prevention focus. In sum, results of the present study supporting evidence for hypotheses, combined effect of entrepreneurial leadership and regulatory focus on innovative behavior through self-efficacy. Experimental results confirmed hypotheses of this study, revealing that promotion focus show more innovative behavior than prevention focus when their leaders' leadership style is entrepreneurial leadership. Also, the paradoxical effect of entrepreneurial leadership and regulatory focus of followers on innovative behavior was mediated by followers' self-efficacy. This study helps explain how leaders' entrepreneurial leadership boost followers' innovative behavior, particularly for those employees who have promotion focus. The current study contributes to the theory of entrepreneurial leadership and regulatory focus and innovation literature. Findings of this study shed light on the organizational processes that shape innovative behavior in venture/startup corporations and provide contributions for venture business field.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.955-962
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• 2005

This study was conducted to examine the nutrient digestibility and ruminal fermentation characteristics in sheep fed diets containing four substitution levels of E. ulmoides leaves for rice straw. For the experiment, they were given a basal diet consisting of rice straw and concentrate at a 3:7 ratio (DM basis). The treatments were designed as a 4$\time$4 Latin square design with four sheep (50.2$\pm$1.6 kg body weight). Sheep were allotted in one of four treatments, which were designed to progressively substitute Eucommia ulmoides for 0, 3, 5 and 10% of rice straw in the basal diet. The digestibility of crude fat was significantly (p<0.05) improved by 12.5 to 17.5% in 3% and 5% air dried Eucommia ulmoides leaves compared with that in control. The digestibility of crude fiber in the 3, 5 and 10% treatments was significantly (p<0.05) higher than that of the control. Dry matter intake was highest (p<0.05) in sheep fed 10% air dried E. ulmoides). Retained nitrogen in the 3, 5 and 10% treatments was increased up to 97%, 173% and 192%, respectively, compared to that in control (p<0.05). Organic matter utilization was higer in 3% and 5% treatments than control (p<0.05). Purine derivatives and microbial nitrogen synthesis were significantly increased by the dietary substitution of 5 % E. ulmoides leaves (p<0.05) compared with control and the 3% treatment. Ruminal concentration of total-VFA was significantly (p<0.05) higher in sheep fed all levels of air dried Eucommia ulmoides than those of control. It is concluded that air-dried E. ulmoides leaves given to ruminants can increase nutrient digestibility and palatability and improve ruminal fermentation. Therefore, the 5 and 10% substitution of E. ulmoides for roughage are highly recommended to be used in practice.

• Journal of The Korean Association For Science Education
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• v.40 no.3
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• pp.337-346
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• 2020

In this study, we investigated the characteristics of students participating in Science Core high schools classes and their relevance to Positive Experiences on Science (hereinafter, PES), and factors causing PES, presented by the students of Science Core high schools. A total of 20 students and five teachers in four regions across the country participated in the in-depth interview, which were conducted with the focus group of students first, and then in-depth interviews with teachers. Based on the interview results, we explored teaching and learning experiences helpful to the PES, assessment experiences resulting in the PES, and ways to support Science Core high schools to enhance their PES. Students and teachers of Science Core high schools argued that students' participation will increase only if they engage in classes while drawing attention within the range that students can understand, students' PES such as scientific interest can be improved through experiments in which students choose topics or design their own exploration process, science competencies such as science problem solving ability and scientific thinking ability should be developed through exploratory experiment activities that fit the nature of science, etc. In addition, regarding ways to improve and support Science Core high schools to enhance PES, securing science class hours, restructuring the contents of science elective courses, and necessity of maintaining Science Core high schools are suggested. Based on the research results of science high school students' PES, ways to improve the PES of general high school students are discussed.