• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.1
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• pp.27-31
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• 2000

Characteristics of ethanol production by a xylose-fermenting yeast, Pichia stipitis Y-7124, were studied. The sugar consumption rate and specific growth rate were higher in the glucose-containing medium than in the xylose-containing medium. Specific activities of xylose reductase and xylitol dehydrogenase were higher in the medium with xylose than glucose, suggesting their induction by xylose. Maximum specific growth rate and ethanol yield were achieved at 30 g xylose/L concentration without formation of by-products such as xylitol and acetic acid whereas a maximum ethanol concentration was obtained at 130 g/L xylose. Adding a respiratory inhibitor, rotenone, increased a maximum ethanol concentration by $10\%$ compared with the control experiment. In order to evaluate the pattern of ethanol inhibition on specific growth rate, a kinetic model based on Luong's equations was applied. The relationship between ethanol concentration and specific growth rate was hyperbolic for glucose and parabolic for xylose. A maximum ethanol concentration at which cells did not grow was 33.6 g/L for glucose and 44.7 g/L for xylose.

• Advances in concrete construction
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• v.11 no.5
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• pp.357-365
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• 2021

High deformable concrete (HDC) elements have compressive strength rates equal to conventional concrete and have got a high compressive strain at about 20% to 50%. These types of concrete elements as prefabricated parts have an abundance of applications in the construction industry which is the most used in the construction of tunnels in squeezing grounds, tunnel passwords from fault zones or swelling soils as soft supports. HDC elements after reaching to compressive yield stress, in nonlinear behavior have hardening combined with increasing strain and compressive strength. The main aim of this laboratory and numerical research is to construct concrete elements with the above properties so the compressive stress-strain behavior of different concrete elements with four categories of mix designs have been discussed and finally one of them has been defined as HDC element mix design. Furthermore, two columns with and without implementing of HDC elements have been made and stress-strain curves of them have been investigated experimentally. An analysis model is presented for columns using finite element method adopted by ABAQUS. The results obtained from the ABAQUS finite element method are compared with experimental data. The main comparison is made for stress-strain curve. The stress-strain curves from the finite element method agree well with experimental results. The results show that the dimension of the HDC samples is significant in the stress-strain behavior. The use of the element greatly increases energy absorption and ductility.

• Journal of Environmental Policy
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• v.8 no.2
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• pp.145-164
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• 2009

Environmental problems, such as the depletion of natural resources, global warming, and the destruction of ecological systems, are among the most serious problems facing the planet. Since the early 1990's, many OECD countries have undertaken green tax reforms by introducing new environmental taxes to protect the environment. Environmental taxes have been used as an instrument of environmental policy more than direct regulation because economic instruments have a comparative advantage over direct regulation in terms of cost effectiveness and pollution abatement incentives. However, one important reason why green tax reforms have not progressed is due to fears regarding the negative effect of environmental taxes on international competitiveness in the industry and trade sectors. The main purpose of this paper is to analyze the effects of environmental taxes on industry and trade by using a theoretical model to compare the effects of environmental taxes on pollution-intensive and energy-saving industries.

• Journal of Information Technology Applications and Management
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• v.26 no.3
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• pp.61-80
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• 2019

The cooperation between universities and industries is already one of the most important factors driving the national economy in the knowledge-based society of the 21st century represented by the Fourth Industrial Revolution. The Korean government has also been carrying out legal and institutional re-adjustments to promote industrial-university cooperation in line with demands for such changes in the times. However, despite this industry-academic cooperation system, there is still a significant mismatch between industrial demand and the university's workforce development system. By the way, there is a Cooperative Education(CO-OP) in Canada and the United States. It's an innovative link between the university and the industry. The reason is that the CO-OP program not only allows students to gain experience with their majors in the industrial field, but also plays a positive role in improving their specialty expertise. In particular, field information, ideas, and job insights that students acquire through CO-OP also serve as motivation for starting a business beyond employment after graduation. Furthermore, CO-OP experience is an important opportunity for future researchers to come up with commercialized research results that are not separated from the field sites The purpose of this study is to overcome the gap between industrial demand and the college manpower training system, and develop a Korean-style coaching program model as a growth engine for creative talent-building policies, represented by 'creation of start-ups and new industry.' In addition, this study suggested measures that can be applied in real universities. In addition, the study also highlighted that the introduction of CO-OP programs with field practices in Korea could also boost start-ups. Based on the Korean CO-OP program model, the curricula applicable to domestic universities consisted of two types : general and research-oriented university types.

• Journal of the Korea Society of Computer and Information
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• v.27 no.10
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• pp.267-274
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• 2022

The purpose of this study is to investigate the learning satisfaction and perception of the students who have taken the online classes of the Digital Innovation Sharing University in the field of new energy industry, and to analyze the relationship between the learning satisfaction and core competencies. In order to achieve this purpose, the results of the learning satisfaction survey of a total of 470 students who took the digital innovation sharing university classes in the new energy industry were analyzed in both quantitative and qualitative methods. As a result of quantitative analysis, students' learning satisfaction was generally above average, and they were particularly satisfied with the setting and operation of educational goals. In addition, it was found that students' learning satisfaction had a statistically significant effect on students' core competencies. As a result of the qualitative analysis, it was possible to confirm the direction of improvement of the curriculum in the areas of function, operation, and content. Based on the results of this study, it is expected that the digital innovation sharing university curriculum quality management feedback system will be prepared in the future, and it will be the foundation for the continuous establishment of the curriculum quality management system.

• Journal of International Area Studies (JIAS)
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• v.14 no.3
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• pp.421-440
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• 2010

This paper examines middle powers' ODA policy in the post cold war era and discusses its implication for Korean aid strategy. Middle powers' ODA has been more successful than that of super powers in promoting donors' positive images and in stimulating recipient countries' development. Middle powers tend to pursue multilateral solutions to international problems often by taking a mediator role, and their ODA policies set them apart from the great players in international politics. Middle powers' ODA is primarily aimed at reducing poverty and protecting human rights in least developed countries where humanitarian aid needs the most rather than promoting donors' interests. Also, middle powers have provided bilateral untied aid in the sectors of food aid and emergency relief and steadily devoted about 0.7% of their gross national income to ODA. Meanwhile, Korea as an emerging middle power and a new donor has been implementing its own aid strategy under the name of the Korean development model since the post cold war period. The Korean ODA was not successful in building donors' positive images by simply following the short term strategies of US and Japan. Yet, its ODA policy has been quite effective in sustaining local development by creating specific niches in which the country can specialize in. In specific, Korea has focused on developing the sectors of information and communication technology and industry energy in recipients' countries by maximizing its comparative advantage.

• Journal of Energy Engineering
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• v.29 no.3
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• pp.74-85
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• 2020

This paper presents an algorithm that evaluated the overload influence by bus upon the distribution system by calculating the daily load curve of PEVs charging by bus based on the daily charging patterns of PEVs according to PEVs penetration scenarios. The proposed algorithm calculates the number of PEVs to estimate the number of households by bus; the probability density function of the charging start time of PEVs, considering driving characteristics of PEVs and the daily load curve of PEVs charging by bus considering battery characteristics according to PEVs penetration scenarios. To verify the evaluation of the overload influence by bus on the distribution system in terms of the proposed algorithm, the cases were reviewed on the target bus(apartment and detached houses) among the feeders of the distribution systems at Dongtan new-town in Korea.

• KIEE International Transactions on Power Engineering
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• v.3A no.1
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• pp.27-34
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• 2003

In this paper, the power conditioner composed of the stand-alone single-phase squirrel cage rotor type self-excited induction generator (SEIG) driven by prime movers such as a wind turbine and a micro gas turbine (MGT) is presented by using the steady-state circuit analysis based on the two nodal admittance approaches using the per-unit frequency in addition to a new state variable defined by the per-unit slip frequency along with its performance evaluations for the stand-alone energy utilizations. The stande-alone single-phase SEIG operating performances in unregulated voltage control loop are then evaluated on line under the conditions of the speed change transients of the prime mover and the stand-alone electrical passive load power variations with the simple theoretical analysis and the efficient computation processing procedures described in the part I of this paper. In addition, a feasuible PI controlled feedback closed-loop voltage regulation scheme of the stande-alone single-phase SEIG is designed on the basis of the static VAR compensate. (SVC) and discussed in experiment for the promising stand-alone power conditioner. The experimental operating performance results are illustrated and give good agreements with the simulation ones. The simulation and experimental results of the stand-alone single-phase SEIG with the simple SVC controller for its stabilized voltage regulation prove the practical effectiveness of the additional SVC control loop scheme including the PI controller with fast response characteristics and steady-sate performance improvements.

• Plant Journal
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• v.4 no.3
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• pp.60-65
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• 2008

Power plant industry has been developed at high-capacity, high-technology, and innovation. Steam turbine became the most useful equipment that dominate more than 50% of all the world electricity production. And developed new materials of the turbine blade and extended length of the turbine last blade brought reform in steam turbine performance upgrade. In this paper, when do partial load driving in high-capacity steam turbine, optimum driving method found whether there is something. In operating steam turbine, there is a lot of loss from secondary wake and throttle of the 1st stage nozzle by the biggest leading factor that load fluctuation affects in high-pressure steam turbine performance. Effect of internal efficiency by 1 stage nozzle is the biggest here, but here fluid flow and flow analysis were not yet examined closely definitely. So, Analyzed design data and acceptance performance test result to applying subcritical pressure drum type 560 MW, supercritical-pressure once through type 500 MW, and 800 MW steam turbines actually. In conclusion, at partial load driving, partial arc admission(PAA) is more efficient than full arc admission(FAA) efficiency. This is judged by because increase being proportional with gross energy of stream that is pressure - available energy if pressure of stream that is flowed in to the turbine increases, available energy becomes maximum and turbine efficiency improves. Therefore, turbine performance is that preview that first stage performance fell if decline is serious in partial load because first stage performance changes according to load.

• Tunnel and Underground Space
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• v.23 no.4
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• pp.261-270
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• 2013

As part of the development of the 3-D geologic modeling software, this study addresses on new development of software modules that can perform the analysis and visualization of the fracture network system in 3-D. The developed software modules, such as BOUNDARY, DISK3D, FNTWK3D, CSECT and BDM, are coded on Microsoft Visual Studio platform using the MFC and OpenGL library supported by C++ program language. Each module plays a role in construction of analysis domain, visualization of fracture geometry in 3-D, calculation of equivalent pipes, production of cross-section map and management of borehole data, respectively. The developed software modules for analysis and visualization of the 3-D fracture network system can be used to tackle the geomechanical problems related to strength, deformability and hydraulic behaviors of the fractured rock masses. All these benefits will further enhance the economic competitiveness of the domestic software industry.