• ALGAE
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• v.28 no.2
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• pp.131-147
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• 2013

Major progress has been made in the past decade towards understanding of the biosynthesis of red carotenoid astaxanthin and its roles in stress response while exploiting microalgae-based astaxanthin as a potent antioxidant for human health and as a coloring agent for aquaculture applications. In this review, astaxanthin-producing green microalgae are briefly summarized with Haematococcus pluvialis and Chlorella zofingiensis recognized to be the most popular astaxanthin-producers. Two distinct pathways for astaxanthin synthesis along with associated cellular, physiological, and biochemical changes are elucidated using H. pluvialis and C. zofingiensis as the model systems. Interactions between astaxanthin biosynthesis and photosynthesis, fatty acid biosynthesis and enzymatic defense systems are described in the context of multiple lines of defense mechanisms working in concert against photooxidative stress. Major pros and cons of mass cultivation of H. pluvialis and C. zofingiensis in phototrophic, heterotrophic, and mixotrophic culture modes are analyzed. Recent progress in genetic engineering of plants and microalgae for astaxanthin production is presented. Future advancement in microalgal astaxanthin research will depend largely on genome sequencing of H. pluvialis and C. zofingiensis and genetic toolbox development. Continuous effort along the heterotrophic-phototrophic culture mode could lead to major expansion of the microalgal astaxanthin industry.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1100-1106
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• 2009

General contractors' overhead costs are increasing relative to direct costs. However, it is difficult to apply the traditional activity-based costing directly to the construction site overhead costing because the resource consumption rate per each activity is varied depending on the attributes of activities. The research develops a methodology of hybrid cost allocation system when resources are assigned to cost objects unlike the traditional activity-based costing. The study also develops a database program and demonstrates how it can be applied to the construction projects using a case study.

• Journal of Engineering Education Research
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• v.23 no.4
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• pp.66-75
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• 2020

This study was conducted using the literature review and survey research to analyze the operational status and effectiveness of the single-track accredited program, which has been mandatory since 2016. The research targets to achieve the purpose of the study were the nationwide engineering education accreditation system operating colleges, departments, and engineering education innovation centers. Finally, 183 copies were collected from faculty members at 69 colleges and 554 copies at the department level. As a result of the survey, the college recognized more positively about the operation of the single-track accredited program, and more than 50% of respondents said that there were difficulties due to the operation of the system. The contents required were analyzed and presented. Based on this, the engineering education accreditation system, including the single-track accredited program, suggested the direction of support at the government level and the ABEEK level to better settle down in the field of engineering colleges.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.395-406
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• 2023

The large amount of energy required for successful crop production is the main challenge in greenhouse cropping systems. As a response to this challenge a comprehensive evaluation of greenhouse energy consumption was carried out in two structurally similar single-span greenhouses with different thermal curtain positions, with particular attention to energy productivity, specific energy, net energy, and energy ratio. The greenhouses are used for strawberry production. In the R-greenhouse (RGH), the thermal curtain hanged directly at the roof ridge, whereas in the Q-greenhouse (QGH), the thermal curtain was placed 5° from an imaginary vertical axis, from the middle of the roof ridge downwards to the north side of the greenhouse roof. The relevant data were recorded using standard methods. The results indicated that the energy expended in the RGH and QGH systems was 2,186.48 and 2,189.26 MJ/m², respectively. Electricity and nitrogen fertilizer contributed the highest energy input in both greenhouses and in all seasons. The output energy was 3.12 and 3.82 MJ/m², respectively, in RGH and QGH in season I and 4.40 and 4.87 MJ/m² in season II. In terms of energy expended, there was no significant difference between the two greenhouses, nor between the two seasons. These results indicate that greenhouses of the size used in this investigation are not viable in terms of energy productivity, energy-use efficiency, and subsequent economic performance. However, further studies should be conducted to scale-up the information obtained from this investigation.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.6
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• pp.159-172
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• 2023

This study aims to empirically investigate the relative effects of business-to-business (vs. business-to-consumer) business model innovation (BMI) on innovation performance. The research examines the impact of three key components of BMI: 1. value creation, 2. value proposition, and 3. value capture, on innovation performance. The 2022 Entrepreneurship Survey data by the Korean Entrepreneurship Foundation was used to analyze 2,879 companies. An exploratory data analysis (EDA) including various categories such as industry, firm, CEO, and technology chracteristics was conducted to show the latest startup status in Korea. The results show that value creation of B2B (vs. B2C) firms has a more positive and significant impact on innovation performance. Whereas, value proposition of B2C (vs. B2B) firms was found to have a more positive and significant effect on innovation performance. Interestingly, value capture did not show any effects for either type of firms. Additionally, the study employed seemingly unrelated regression (SUR) analysis for robustness checks. These findings provide important insights about the relative effects of B2B-BMI (vs. B2C-BMI).

• Journal of Engineering Education Research
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• v.25 no.5
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• pp.12-19
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• 2022

This study explored the determinants of first job employment outcomes(employment status, salary, company size) of engineering college graduates using 2018 Graduates Occupational Mobility Survey(GOMS) data. Independent variables were used as variables for personal characteristics, academic background, and job preparation efforts. The priorities and interactions between the factors determining employment outcomes were identified using the decision tree analysis. The research results are as follows. First, it was found that the most important factor in determining the 'first job employment status' was 'exam preparation(public and private company, test for teacher recruitment)' among individual's job preparation efforts. Second, the most important factor in determining 'first job salary' was 'gender' among individual characteristics. Third, the most important factor in determining the 'first company size' was the experience of 'corporate job aptitude study' among individual's job preparation efforts. Based on the results of the analysis, suggestions for establishing customized career development strategies for engineering college students were presented.

• Proceedings of the Korea Society of Mathematical Education Conference
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• 2010.04a
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• pp.281-289
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• 2010

Experiment teaching is an important part for science and engineering colleges, teaching through different pilot projects: First, help students to consolidate the theory of operation; second, trail students the capacity and the ability to solve practical problems. Improve students the curriculum of learning, and promote the formation of students to discover and solve the problem. of the basic quality in training students hands-on ability and ability to innovate, while guiding them to develop the attitude of scientific truth-seeking, the style of rigorous and thorough and the spirit of unity and coordination.

• Journal of Engineering Education Research
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• v.22 no.1
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• pp.22-28
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• 2019

The purpose of this study is to develop instructional design model of flipped learning suitable for engineering education field and to draw out effects and improvements by applying it to actual lessons for engineering college students. Literature review and case studies were conducted to achieve the purpose of the study. For a case study, flipped learning was applied to 'creative problem solving methodology' which is a liberal arts course of engineering college at D university in Gyeonggi-do. As a result of the literature review, the PARTNER model was applied and weekly instructional guide was presented by each stage. In addition, the results of analysis on the reflection journal showed that the students were more able to achieve the deepening learning stage through active participation in class than the existing class, and found that they had a more challenging plan after the class.

• Journal of Sensor Science and Technology
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• v.29 no.4
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• pp.270-274
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• 2020

In this study, a read-out integrated circuit (ROIC) that can be applied to a colorimetry-based optical sensor for analyzing total phosphorus and total nitrogen was developed and characterized. The proposed ROIC minimizes the effect on temperature fluctuation, improves sensitivity, and extends the dynamic range by utilizing a dual optical path and feedback control circuit. Using a dual optical path makes it possible to calibrate the output signal of the optical sensor automatically, along with the temperature fluctuation. The calibrated voltage is fed back into the measurement stage; thus, the output current of the measurement is adaptively controlled. As a result, the sensitivity and dynamic range of the proposed ROIC are improved. Finally, a total-phosphorus analysis was conducted by utilizing the ROIC. The ROIC was found to operate stably over a wide temperature range.

• Advances in environmental research
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• v.2 no.3
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• pp.245-260
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• 2013

Biosorption represents a technological innovation as well as a cost effective excellent remediation technology for cleaning up radionuclides from aqueous environment. In the present study, a bacteria strain FB12 with high adsorption rate of uranium ion was isolated from the vicinity of the nuclear power plant. It was tentatively identified as Bacillus sp.FB12 according to the 16S rDNA sequencing. Efforts were made to further improve the adsorption rate and genetic stability by UV irradiation and UV-LiCl cooperative mutagenesis. The improved strain named Bacillus sp.UV32 obtains excellent genetic stability and a high adsorption rate of 95.9%. The adsorption of uranium U (VI) by Bacillus sp.UV32 from aqueous solution was examined as a function of metal ion concentration, cell concentration, adsorption time, pH, temperature, and the presence of some foreign ions. The adsorption process of U (VI) was found to follow the pseudo-second-order kinetic equation. The adsorption isotherm study indicated that it preferably followed the Langmuir adsorption isotherm. The thermodynamic parameters values calculated clearly indicated that the adsorption process was feasible, spontaneous and endothermic in nature. These properties show that Bacillus sp.UV32 has potential application in the removal of uranium (VI) from the radioactive wastewater.