• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.297-297
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• 2010

Precise control of the position and density of doping elements at the nanoscale is becoming a central issue for realizing state-of-the-art silicon-based optoelectronic devices. As dimensions are scaled down to take benefits from the quantum confinement effect, however, the presence of interfaces and the nature of materials adjacent to silicon turn out to be important and govern the physical properties. Utilization of visible light is a promising method to overcome the efficiency limit of the crystalline Si solar cells. Si quantum dots (QDs) have been proposed as an emission source of visible light, which is based on the quantum confinement effect. Light emission in the visible wavelength has been reported by controlling the size and density of Si QDs embedded within various types of insulating matrix. For the realization of all-Si QD solar cells with homojunctions, it is prerequisite not only to optimize the impurity doping for both p- and n-type Si QDs, but also to construct p-n homojunctions between them. In this study, XPS and SIMS were used for the development of p-type and n-type Si quantum dot solar cells. The stoichiometry of SiOx layers were controlled by in-situ XPS analysis and the concentration of B and P by SIMS for the activated doping in Si nano structures. Especially, it has been experimentally evidenced that boron atoms in silicon nanostructures confined in SiO2 matrix can segregate into the Si/$SiO_2$ interfaces and the Si bulk forming a distinct bimodal spatial distribution. By performing quantitative analysis and theoretical modelling, it has been found that boron incorporated into the four-fold Si crystal lattice can have electrical activity. Based on these findings, p-type Si quantum dot solar cell with the energy-conversion efficiency of 10.2% was realized from a [B-doped $SiO_{1.2}$(2 nm)/$SiO_2(2\;nm)]^{25}$ superlattice film with a B doping level of $4.0{\times}10^{20}\;atoms/cm^2$.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.32-40
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• 2009

To understand contribution of thermophilic microorganisms in decomposition of litter deposits on shore of lakes, we surveyed a lakeshore litter deposit for bacteria growing at $60^{\circ}C$. Ten thermophilic isolates were selected for in-depth characterization, based on their high capacity to degrade high molecular weight organic compounds. Based on phylogenetic analysis on their 16S rRNA gene sequences, all isolates were identified as Geobacillus. The optimal growth temperature and pH of the strains ranged $55{\sim}60^{\circ}C$ and 6.0${\sim}$8.0, respectively. Salinity was inhibitory to the growth of the isolates, showing marked decrease of growth rates at 3% salinity. Based on activities of hydrolytic enzymes and profiles of carbohydrate utilization (determined by API 50 CHB kit), three G. stearothermophilus strains showed patterns clearly distinctive from other isolates. Two G. kaustophilus strains also demonstrated distinctiveness in their metabolic pattern and ecological parameters. However, ecological and metabolic profiles of the other five isolates were more variable and showed some degree of digression from their phylogenetic classification. Therefore, it could be concluded that endospore-forming thermophilic bacteria in lakeshore litter deposits contribute to degradation of organic materials with diverse ecological niches while having successions similar to microbial flora in compost. We propose that the thermophilic isolates and/or their thermo-tolerant enzymes can be applied to industrial processes as appropriate mixtures.

• Journal of the Korean School Mathematics Society
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• v.20 no.1
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• pp.57-76
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• 2017

Since the 1990s, Korea has been developing various policies and materials for the improvement of basic learning abilities. In this study, the cases of policies for underachievers in Korea and the US were compared and analyzed the programs for mathematics underachievers in elementary school with Chuncheon office of education and Seattle public schools. All of them started from the point of relief of underachievers, but they differed in the process of operating them specifically. This study suggests the followings. First, active utilization of vacation programs to solve problems such as low-income meal service, prevention of stigma effects, securing teacher's instruction time, teacher-instructor cooperation. Second, the necessity of detailed activity-centered textbooks that underachievers can explore with interest in mathematics learning and easy to use by teachers. Third, specific cooperation for inducing interest of their own children's learning and forming close ties between parents and teachers. Fourth, program analysis by a professional evaluation group to improve the quality of underachiever program.

• Journal of Life Science
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• v.25 no.9
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• pp.1072-1079
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• 2015

The lees of Korean traditional wine called as Jubak or Sul-jigemi in Korea is byproduct from alcohol fermentation industry, which is remnant of fermentation broth after filtration, centrifugation, distillation, or sedimentation during aging. Since, Korean traditional wines are produced from edible plant sources such as rice, foxtail millet, fruits and medicinal herbs with nuruk (a traditional fermentation starter and starch degrader), the Jubak from rice wine (takju), medicinal herb wine (yakju) and fruits wine are considered as safe byproduct and have various useful bioactivity. Considering the recent rapid increased production of Jubak from takju industry, and the reinforcement of dispose of Jubak as waste material in worldwide, the development of efficient reuse process for Jubak is necessary in traditional wine industry. In this review, the status of current industry, research and patent trends in relation with Jubak production, treatment, utilization and renewal was analyzed and different bioactive compounds including phenolic acids from Jubak were provided. Jubak is not any more waste material, and is the source of bioactive functional materials for food, cosmetics and medicinal industry. To develop the efficient and economic renewal technology including recovery process for bioactive substances from Jubak, systematic collaboration and research among the industry, academy and government is necessary.

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.127-133
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• 2024

The elbow joint is made up of three different bones. X-rays or other radiological exams are commonly used to diagnose elbow injuries or disorders caused by physical activity and external forces. Previous research on the elbow joint reported a new examination method that meets the imaging evaluation criteria in the tilt position by Z-axis elevation of the forearm. Therefore, this study aims to design an optimized instrument and develop an aid applicable to other upper extremity exams. After completing the 2D drawing and 3D modeling design, the final design divided into four parts was fabricated with a 3D printer using ABS plastic and assembled. The developed examination aid consists of a four-stage Z-axis elevation tilt angle function (0°, 5°, 10°, and 15°) and can rotate and fixate 360° in 1-degree increments. It was designed to withstand a maximum equivalent stress of 56.107 Pa and a displacement of 1.6548e-5 mm through structural analysis to address loading issues caused by cumulative frequency of use and physical utilization. In addition to X-ray exams of the elbow joint, the developed aid can be used for shoulder function tests by rotating the humerus and also be applied to MRI and CT exams as it is made of non-metallic materials. It will contribute to the accuracy and efficiency of medical imaging diagnosis through clinical applications of various devices and medical imaging exams in the future.

• Food Science and Preservation
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• v.19 no.2
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• pp.243-248
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• 2012

The physicochemical properties and nutritional components of fermented black jujube (FBJ) were compared with those of dried jujube (DJ) to improve their utilization as food materials. The moisture contents and brix of the DJ and FBJ were 22.6% and 6.07 brix, and 10.36% and 7.23 brix, respectively. Their L values were 34.78 and 31.82, and the a and b values of DJ were higher than those of FBJ. DJ had a lower water activity level (0.75) than FBJ (0.45), but FBJ had a higher amount of reducing sugar and soluble protein than DJ. The major free sugars in the two types of jujube were fructose and glucose, and their potassium content was highest (about 90%) among minerals. Their unsaturated fatty acid contents were 51.0% and 59.83%, respectively, and the major fatty acids myristoleic acid, palmitic acid, and palmitoleic aid were detected in them.

• Journal of The Korean Association For Science Education
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• v.33 no.5
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• pp.1007-1020
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• 2013

This study investigated the perceptions and the characteristics of elementary teachers on teaching science-arts integrated activities. Twelve elementary teachers who have taught in the third to sixth grade science lessons participated in this study. Data was collected by individual interviews lasting 60 to 90 minutes. Interview questions were composed of three aspects: 1) how elementary teachers perceive science-arts integrated activities, 2) in what ways elementary teachers address science-arts integrated activities, and 3) what difficulties elementary teachers experienced in addressing science-arts integrated activities. The results showed that, first, elementary teachers agreed that science-arts integrated activities have educational value in science learning. Second, most teachers focused on improving understanding of science knowledge through teaching science-arts integrated activities, while several teachers put emphasis on having experience of arts as well as understanding of science knowledge. And third, teachers experienced difficulties due to insufficient teaching materials and time to prepare for teaching science-arts integrated activities. Based on the results, we suggested educational implications for utilization of science-arts integrated activities in elementary education.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.6
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• pp.85-105
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• 2021

In this study, a case study was conducted on Advanced Nano Products Co.,Ltd, a company that was established in 2000 and has the core technology to produce and commercialize nano materials and ultrafine nano powders based on nano technology. Deviating from the general case study, a case study analysis frame was set based on the theory of technology management and industry-university cooperation theory, and cases were analyzed. In this case study, Advanced Nano Products Co.,Ltd. was analyzed from two analytical perspectives: the establishment of a Management Of Technology system within the company and the Industry-Academic Cooperation activity. Based on this theoretical-based analysis framework, company visit interviews and related data research and analysis were conducted. As a result of the study of the case company, it was possible to derive how the technology management and industry-university cooperation affect the growth stage of the company as follows. First, the strategic use of technology management is an important factor in strengthening the competitive advantage and core competencies of venture companies, and for survival and growth of startups in the early stages. Second, strategic use of technology management and patents and establishment of a patent management system are a part of business strategy and play a pivotal role in corporate performance. Third, the human and material infrastructure of universities affects the growth of companies in the early stage of start-up, and the high utilization of industry-university cooperation promotes the growth of companies. Fourth, continuous industry-academic cooperation activities in the growth and maturity stages of a company's growth stage are the basis for activating external exchanges and building networks. Lastly, technology management and industry-university cooperation were found to be growth factors for each growth stage of a company. In order for a company to develop continuously from the start-up to the growth and maturity stages, it is necessary to establish a technology management system from the beginning and promote strategic technology management activities. In addition, it can be said that it is important to carry out various industry-academic cooperation activities outside the company. As a result of the case analysis, it was found that Advanced Nano Products Co.,Ltd, which performed these two major activities well, overcame the crisis step by step and continued to grow until now. This study shows how the use of technology management and industry-academic cooperation creates value in each growth stage of technology-based venture companies. In addition, its active use will play a big role in the growth of other venture companies. The results of this case study can be a valid reference for growth research of technology start-up venture companies and related field application and utilization.

• Applied Biological Chemistry
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• v.13 no.2
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• pp.153-170
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• 1970

1. Isolation and identification of amylase-producing bacteria. The powerful strain A-12 and S-8 were respectively isolated from air and soil after screening a large number of amylase-producing bacteria. Their bacterial characteristics have been investigated and it has been found that all characteristics of strain A-12 and S-8 are similar to Bac. subtilis of Bergey's manual except for the acid formation from a few carbohydrates and the citrate utilization, i.e., the strain A-12 shows negative in the citrate utilization, and the acid formation from arabinose and xylose, S-8 shows negative in the acid formation from xylose. 2. Amylase production by Liquid cultures with solid materials. Several conditions for amylase production by strain A-12 in stationary cultures have been studied. The results obtained are as follows. (1) The optimum conditions are:temperature $35^{\circ}C$, initial pH 6.5 to 7.0 and incubation time 3 to 4 days. (2) The amylase production is not affected by the preservation period of the stock cultures. (3) Among the various solid material, the defatted soy bean is found to be the best for t1e amylase production. However, the alkali treatment of the defatted soy bean gives no effect contrary to the cage of defatted rape seed. The addition of soluble starch to the alkali extract of defatted soy bean shows the increased amylase production. (4) Up to 1% addition of ethanol to carbon dificient media gives the improved amylase production, whereas the above effect is not found in the case of carbon rich media. (5) The amylase production can be increased 2.5 times when 10% of defatted soy bean is admixed to cheaply available wheat bran. (6) The excellent effect is found for amylase production when 20% of wheat bran is admixed to defatted dry milk which is a poor medium. The activity is found to be $D^{40^{\circ}}_{30'}$ 7,000(L.S.V. 1,800) in 10% medium. (7) No significant effect is observed due to the addition of various inorganic salts. 3. Amylase production by solid cultures. Several conditions for amylase production by strain A-12 in wheat bran cultures have been studied and the results obtained are as follows. (1) The optimum conditions: are temperature $33^{\circ}C$, incubation lime 2 days, water content added 150 to 175% and the thickness of the medium 1.5cm, The activity is found to be $D^{40^{\circ}}_{30'}$ 36,000(L.S.V. 15,000) (2) No significant effect is found in the case of the additions of various organic and inorganic substances.

• 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.