• Journal of Animal Science and Technology
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• v.50 no.2
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• pp.199-208
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• 2008

This study was undertaken to investigate the effects of ruminally protected amino acids (Methionine and Lysine) on in vitro ruminal parameters, and in vivo milk yield and milk composition in mid-lactating cows. In the first in vitro experiment, there were no statistical significances between treatments in ruminal pH and dry matter digestibility during various incubation times. In the second in vivo experiment, milk yield decreased by 11.92% in control and 5.68% in the treatment respectively, but decrease rate of milk yield in the treatment was lower than control. Milk yields naturally decreased as time goes by since the DIMs(Days in milk) of the cows in experiment were in mid-lactation period. 4% FCM(Fat corrected milk) and milk protein yields also, respectively, decreased by 11.25% and 11.09% in control and 6.16% and 5.47% in the treatment as compared with the intial. Milk protein and milk fat production were higher in the treatment(0.90kg, 1.10kg) than those of control(0.66kg, 0.79kg). Milk fat content significantly increased with supplementing protected amino acids as compared to control(P<0.05). From the above results, protected amino acids were positively utilized in the performances of mid-lactating cows without inhibiting rumen fermentation. Further investigation is suggested for essential amino acid composition and intestinal digestion rate out of rumen bypass protein in dietary protein to be estimated.

• Korean Journal of Food Science and Technology
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• v.52 no.3
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• pp.226-236
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• 2020

This study was designed to evaluate the biological activities and main constituents of different parts (fruit, leaf, and stem) of aronia (Aronia melanocarpa). The total phenolic and flavonoidcontents, DPPH and ABTS⁺ radical-scavenging activity, reducing power, and ferric reducing/antioxidant power were observed to follow the order of: leaves > stems > fruits, regardless of extraction solvents. The inhibitory activity against lipopolysaccharide-induced NO production in Raw 264.7 cells was significantly higher in the aronialeaf extract-treated group than in the groups treated with stem and fruit extracts. The ultra-performance liquid chromatography (UPLC) analysis was mainly composed of routine. In addition, the highest content level was measured in the case of the catechinmemberepigallocatechin witha higher value than that found in green tea. Theresults of this studyprovide useful information for understanding the chemical constituents and biological activities of aroniafruits and byproducts.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.3 s.118
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• pp.248-256
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• 2007

In this paper, we propose a selective DFT spreading method to solve a high PAPR problem in uplink OFDMA system. A selective characteristic is added to the DFT spreading, so the DFT spreading method is mixed with SLM method. However, to minimize increment of computational complexity, differently with common SLM method, our proposed method uses only one DFT spreading block. After DFT, several copy branches are generated by multiplying with each different matrix. This matrix is obtained by linear transforming the each phase rotation in front of DFT block. And it has very lower computational complexity than one DFT process. For simulation, we suppose that the 512 point IFFT is used, the number of effective sub-carrier is 300, the number of allowed sub-carrier to each user's is 1/4 and 1/3 and QPSK modulation is used. From the simulation result, when the number of copy branch is 4, our proposed method has more than about 5.2 dB PAPR reduction effect. It is about 1.8 dB better than common DFT spreading method and 0.95 dB better than common SLM which uses 32 copy branches. And also, when the number of copy branch is 2, it is better than SLM using 32 copy branches. From the comparison, the proposed method has 91.79 % lower complexity than SLM using 32 copy branches in similar PAPR reduction performance. So, we can find a very good performance of our proposed method. Also, we can expect the similar performance when all number of sub-carrier is allocated to one user like the OFDM.

• Journal of Korea Port Economic Association
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• v.35 no.4
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• pp.1-16
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• 2019

The purpose of this study is to Analyze the problems that container shipping companies exist through the commercialization of container shipping for Non-Arctic countries and the opportunity factors for the transport of the Arctic shipping to improve cooperation cross-border relation Arctic policy and the use of transport. In order to design a hierarchy analysis method study model, four high and 17 low factors were extracted by designing a hierarchy analysis method study model based on results by prior study and in-depth interview. The first of the higher factors is the internal strength of assessing the value of the Arctic, the will and capabilities of the shipping companies in creating new markets with the vision and goals of the shipping companies. Second, the internal constraints associated with the shipping companies advance to the NSR mean the negative factors for the entry into the NSR and the internal weaknesses that cause the shipping companies capacity limitations. Third, the economic benefits from the use of NSR are external factor for shipping companies in cooperation with the future economic value of the Arctic and with respect to Arctic sea and Arctic advance and development from Arctic coastal countries. Finally, external pre-emptive tasks means to respond to use NSR by external restrictions on transport to prepare the possibility of severe weather conditions, the customs policy change of coastal countries.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.473-479
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• 2012

Water reuse has been highlighted as a representative alternative to solve the lacking water resource. This study carried out a study on the pipe corrosion and water quality change which can occur through the supply of reclaimed water, using a simulated reclaimed water distribution pipeline. Galvanized steel pipe (GSP), cast iron pipe (CIP), stainless steel pipe (STSP) and PVC pipe (PVCP) were used for the pipe materials. Reclaimed water(RW) and tap water(TW) were respectively supplied into simulated reclaimed water distribution pipelines. As a result of performing a loop test to supply reclaimed water to simulated reclaimed water distribution pipelines, the weight reduction of pipe coupons showed the sequence of CIP > GSP > STSP ${\approx}$ PVCP. In addition, reclaimed water showed a high corrosion rate comparing to that of tap water. In case of CIP, the initial corrosion rate showed 3.511 mdd(milligrams per square decimeter per day) for reclaimed water and 2.064 mdd for tap water and the corrosion rate for 90 days showed 0.833 mdd for reclaimed water and 0.294 mdd for tap water. Also in case of GSP, the initial corrosion rate showed 2.703 mdd for reclaimed water and 2.499 mdd for tap water and the corrosion rate for 90 days showed 0.349 mdd for reclaimed water and 0.248 mdd for tap water, which was a tendency similar to that appeared in CIP with a tendency to reduce the corrosion rate. As a result of water quality changes of reclaimed water at pipe materials to carry out the loop test, there was higher conversion ratio of ammonia into nitrate in CIP and GSP with higher corrosion rate than that in STSP and PVCP where no corrosion has occurred. The highest denitrification rate of nitrate could be observed from CIP with the most particles generated from corrosion. In CIP, it could be confirmed that there was MIC (Microbiologically Induced Corrosion) as a result of EDS (Energy Dispersive X-ray spectrometer System) analysis results.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.165-174
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• 2010

The numerical modeling of a coal gasification reaction occurring in an entrained flow coal gasifier is presented in this study. The purposes of this study are to develop a reliable evaluation method of coal gasifier not only for the basic design but also further system operation optimization using a CFD(Computational Fluid Dynamics) method. The coal gasification reaction consists of a series of reaction processes such as water evaporation, coal devolatilization, heterogeneous char reactions, and coal-off gaseous reaction in two-phase, turbulent and radiation participating media. Both numerical and experimental studies are made for the 1.0 ton/day entrained flow coal gasifier installed in the Korea Institute of Energy Research (KIER). The comprehensive computer program in this study is made basically using commercial CFD program by implementing several subroutines necessary for gasification process, which include Eddy-Breakup model together with the harmonic mean approach for turbulent reaction. Further Lagrangian approach in particle trajectory is adopted with the consideration of turbulent effect caused by the non-linearity of drag force, etc. The program developed is successfully evaluated against experimental data such as profiles of temperature and gaseous species concentration together with the cold gas efficiency. Further intensive investigation has been made in terms of the size distribution of pulverized coal particle, the slurry concentration, and the design parameters of gasifier. These parameters considered in this study are compared and evaluated each other through the calculated syngas production rate and cold gas efficiency, appearing to directly affect gasification performance. Considering the complexity of entrained coal gasification, even if the results of this study looks physically reasonable and consistent in parametric study, more efforts of elaborating modeling together with the systematic evaluation against experimental data are necessary for the development of an reliable design tool using CFD method.

• Journal of the Korean Electrochemical Society
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• v.18 no.3
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• pp.121-129
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• 2015

The platinum anode for the electrolytic reduction process is generally surrounded by a nonporous ceramic shroud with an open bottom to offer a path for $O_2$ gas produced on the anode surface and prevent the corrosion of the electrolytic reducer. However, the $O^{2-}$ ions generated from the cathode are transported only in a limited fashion through the open bottom of the anode shroud because the nonporous shroud hinders the transport of the $O^{2-}$ ions to the anode surface, which leads to a decrease in the current density and an increase in the operation time of the process. In the present study, we demonstrate the electrolytic reduction of 1 kg-uranium oxide ($UO_2$) using the porous shroud to investigate its long-term stability. The $UO_2$ with the size of 1~4mm and the density of $10.30{\sim}10.41g/cm^3$ was used for the cathode. The platinum and 5-layer STS mesh were used for the anode and its shroud, respectively. After the termination of the electrolytic reduction run in 1.5 wt.% $Li_2O-LiCl$ molten salt, it was revealed that the U metal was successfully converted from the $UO_2$ and the anode and its shroud were used without any significant damage.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.2
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• pp.183-221
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• 2013

While in the early stages of space activities only a few states engaged in the use of outer space, as is well known, commercial space activities have grown dramatically in recent years. Both states, state institutions, and international governmental organizations as well as many private enterprises are engaged in such commercial use of outer space by now. This development is not reflected in the present state of space law. The existing international instruments of space law were developed and finalized before this development and thus only provide very few and sometimes unfitting provisions for the commercial use of outer space and particularly the use by private enterprises. Law formulated in an era when the word "privatization" had not even been coined cannot contain potential problems caused by the increasing commercialization of outer space. For the promotion and further development of such commercial use of outer space it is necessary to clarify and establish the legal framework for such use, because participants will need this information for their future investments in this field. The purpose of this paper is to research and make an analysis of the contents and international regulation of international space commerce, which is rapidly proliferating and to review the process of improvement on national legislations relating to the commercialization of outer space in a few main space advanced countries to make the sustainable progress of commercial space activities project in international society. The legal implications of matters such as international commercial launch services, the liability aspects of such services, intellectual property rights, insurance, product liability insurance and materials processing could one day will be subject to regulated by international space law as well as domestic law. In fact, the question of commercialization is linked to the question of sharing benefits of space activities, and this currently is an agenda item in the Legal Subcommittee of UN COPUOS. Most of developed countries have enacted the national legislation for commercial space activities relating to the development of our space as follows : The National Aeronautic and Space Act of 1958 and the Commercial Space Act of 1998 in the United States, Outer Space Act of 1986 in England, Establishment Act of National Space Center of 1961 in France, Canadian Space Agency Act of 1990 in Canada, Space Basic Act of 2008 in Japan, and Law on Space Activity of 1993 in Russia. Becides there are currently three national legislations relating to space development and commercial space activities in Korea as follows : Aerospace Industry Development Promotion Act of 1987, Outer Space Development Promotion Act of 2005, Outer Space Damage Compensation Act of 2008. Commercial space great promise for the utilization and expansion of human outer space activities but aspring commercial actors must recognize that foreign policy, as well as obligations to the international community as a whole, ensure that commercial space activities will not operate in a legal and regulatory vacuum. As commercial space matures the law and accompanying regulation will most certainly evolve and choose to become participants in the inevitable evolution of law and regulation.

• Journal of the Korean Chemical Society
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• v.62 no.4
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• pp.299-313
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• 2018

Inquiry-centered education is important in science education, but in the actual education field, scientific research is being done in a uniform manner due to realistic difficulties. In this study, we use RS (Reverse Science) as a secondary chemistry class to provide opportunities for students to engage in inquiry learning and scientific thinking through process-oriented activities. In this study, we developed and applied it to explore the effects on the scientific inquiry abilities of middle school students and checked the students' perception of it. For the application of the program, 128 students were selected from 6 classes of the 2nd grade in D district middle school, 64 from the experimental group and 64 from the comparative group. The experimental group taught RSP-based the chemistry inquiry programs and the comparative group taught instructor-led classes and verification experiments on the same topic over the seventh hour with three themes. In addition, we analyzed the results of the pre- and post-test by using the science inquiry ability test, and discussed the effects of the program based on the students' perceptions through class observation, student activity area, questionnaire and interview. As a result, the class using the program showed statistically significant changes in the science inquiry ability of secondary school students. Specifically, the experimental group was found to be significant in its prediction among the subcomponents of basic exploration ability compared to the comparative group. The differences have also been shown to be significant in terms of data translation, hypothesis setup and variable control, which are subcomponents of integrated exploration capabilities (p <. 05). In addition, students became interested in the process of creating the theory of science, and were highly interested in collaborating with their friends. It also provided students with opportunities to experience scientific thinking through process-oriented inquiry. Finally, based on the positive impact of the RSP-based chemistry inquiry program on students, we were able to identify the potential use of the program.

• Sijohaknonchong
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• v.44
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• pp.105-138
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• 2016

Recently with the research function, "XML Digital collection of Sijo Texts in the Period of Modern Enlightenment" DB data is being provided through the Korean Research Memory (http://www.krm.or.kr) and the foundation for the constructing the contents of Sijo Texts in the Period of Modern Enlightenment has been laid. In this paper, by reviewing the characteristics and problems of Digital collection of Sijo Texts in the Period of Modern Enlightenment and searching for the improvement, I tried to find a way to make it into the content. This database has the primary meaning in the integrating and glancing at the vast amounts of Sijo in the Period of Modern Enlightenment to reaching 12,500 pieces. In addition, it is the first Sijo data base which is provide the variety of search features according to literature, name of poet, title of work, original text, per period, and etc. However, this database has the limits to verifying the overall aspects of the Sijo in the Period of Modern Enlightenment. The title and original text, which is written in the archaic word or Chinese character, could not be searched, because the standard type text of modern language is not formatted. And also the works and the individual Sijo works released after 1945 were missing in the database. It is inconvenient to extract the datum according to the poet, because poets are marked in the various ways such as one's real name, nom de plume and etc. To solve this kind of problems and improve the utilization of the database, I proposed the providing the standard type text of modern language, giving the index terms about content, providing the information on the work format and etc. Furthermore, if the Sijo database in the Period of Modern Enlightenment which is prepared the character of the Sijo Culture Information System could be built, it could be connected with the academic, educational contents. For the specific plan, I suggested as follow, - learning support materials for the Modern history and the national territory recognition on the Modern Age - source materials for studying indigenous animals and plants characters creating the commercial characters - applicability as the Sijo learning tool such as Sijo Game.