• Journal of the Korean Vacuum Society
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• v.20 no.3
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• pp.225-232
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• 2011

Reactive ion etching (RIE) technique for maskless surface texturing of mc-silicon solar wafers has been applied and succeed in fabricating a grass-like black-silicon with an average reflectance of $4{\pm}1%$ in a wavelength range of 300~1,200 nm. In order to investigate the optimized texturing conditions for mass production of high quantum efficiency solar cell Surface characteristics such as the spatial distribution of average reflectance, micrscopic surface morphology and minority carrier lifetime were monitored for samples from saw-damaged $15.6{\times}15.6\;cm^2$ bare wafer to key-processed wafers as well as the mc-Si solar cells. We observed that RIE textured wafers reveal lower average reflectance along from center to edges by 1% and referred the origin to the non-uniform surface structures with a depth of 2 times deeper and half-maximum width of 3 times. Samples with anti-reflection coating after forming emitter layer also revealed longer minority carrier lifetime by 40% for the edge compared to wafer center due to size effects. As results, mc-Si solar cells with RIE-textured surface also revealed higher efficiency by 2% and better external quantum efficiency by 15% for edge positions with higher height.

• Journal of Korean Society on Water Environment
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• v.22 no.3
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• pp.451-455
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• 2006

Heterotrophic biomass yield coefficients, $Y_H$, for aerobic, anoxic and anaerobic reactors were successfully estimated for the two wastewater treatment plants, where one plant was operating in the $A^2/O$ process and the other was operating in the 4-stage BNR process. The estimation of $Y_H$ was undertaken by plotting the biomass COD concentrations versus the soluble COD concentrations in order to calculate the ${\Delta}biomass$ COD/ ${\Delta}soluble$ COD in each batch reactor. The batch reactors employed in this study were fed by filtered influent and mixed liquors in the ratio of 10:1, and operated in the aerobic, anoxic and anaerobic conditions, which represented the actual operating conditions for the $A^2/O$ and 4-stage BNR process. The average $Y_H$ values of the aerobic, anoxic and anaerobic reactor for the $A^2/O$ process were 0.52, 0.41 and 0.18 mg COD/mg COD, respectively, and those for the 4-stage BNR process were 0.58, 0.40 and 0.20 mg COD/mg COD, respectively. The average ratio of the $Y_H$ for aerobic reactors to those for the anoxic reactors were about 1:0.79 for the $A^2/O$ process, and about 1:0.69 for the 4-stage BNR process. The experimental method for anoxic and anaerobic $Y_H$ estimation shown in this study has turned out to be simple and efficient in its practical application.

• Journal of Society of Preventive Korean Medicine
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• v.16 no.3
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• pp.89-105
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• 2012

Objectives : This study was carried out to know the status of clinical utilization of Korean medical knowledge and the Korean medical knowledge system which Korean medical doctors want. Methods : Questionnaires were distributed to Korean medical doctors registered for the Association of Korean medicine via the email and 249 answered questionnaires were analyzed. Results : 50.6 % of Korean medical doctors utilized the textbooks for Korean medicine when they treated their patients. The reason why they did not utilize the textbooks for Korean medicine was mostly that 'it could not be applied directly into clinical application with only contents of textbook because clinical approach (diagnosis and treatment methods) was not clearly described in the textbook'. 48.6 % of Korean medical doctors utilized the EBM materials when they treated their patients. EBM materials that they referred included domestic articles, other EBM materials excluding papers and international academic papers based on PubMed in order. The reasons why they did not utilize the EBM materials were mostly that 'it was difficult to find the evidence' and 'EBM materials were not actually helpful for the clinical practice.' It was found that Korean medical doctors approached the disease in aspects of Korean and Western Medicine concurrently upon the diagnosis of patients and performed the diagnosis and treatment of Korean medicine on the diseases which seemed to be effective with Korean medicine. It was also found that they thought that they needed to know the Western medical knowledge as much as general doctors who have a doctor's license or family medicine specialists who comprehensively treat the general diseases know. Korean medical doctors wanted to have the systematic summary of modern research performance in fields of acupoint, acupuncture, herbal drugs and formula. They thought that constitutional medicine and Sa-am acupuncture therapy were representative characteristics in Korean medicine differentiated from Traditional Chinese medicine and Kampo medicine. Conclusions : Korean medical doctors wanted to establish the Korean medical knowledge system based on evidence focusing on clinical and practical contents. New Korean medical knowledge system should be established based on these requirements in the future.

• Communications of Mathematical Education
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• v.20 no.1 s.25
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• pp.117-145
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• 2006

Mathematically gifted children have creative curiosity about novel tasks deriving from their natural mathematical talents, aptitudes, intellectual abilities and creativities. More effect in nurturing the creative thinking found in brilliant children, letting them approach problem solving in various ways and make strategic attempts is needed. Given this perspective, it is desirable to select open-ended and atypical problems as a task for educational program for gifted children. In this paper, various types of open-ended problems were framed and based on these, teaming activities were adapted into gifted children's class. Then in the problem solving process, the characteristic of bright children's mathematical thinking ability and examples of problem solving strategies were analyzed so that suggestions about classes for bright children utilizing open-ended tasks at elementary schools could be achieved. For this, an open-ended task made of 24 inquiries was structured, the teaching procedure was made of three steps properly transforming Renzulli's Enrichment Triad Model, and 24 periods of classes were progressed according to the teaching plan. One period of class for each subcategories of mathematical thinking ability; ability of intuitional insight, systematizing information, space formation/visualization, mathematical abstraction, mathematical reasoning, and reflective thinking were chosen and analyzed regarding teaching, teaming process and products. Problem solving examples that could be anticipated through teaching and teaming process and products analysis, and creative problem solving examples were suggested, and suggestions about teaching bright children using open-ended tasks were deduced based on the analysis of the characteristic of tasks, role of the teacher, impartiality and probability of approaching through reflecting the classes. Through the case study of a mathematics class for bright children making use of open-ended tasks proved to satisfy the curiosity of the students, and was proved to be effective for providing and forming a habit of various mathematical thinking experiences by establishing atypical mathematical problem solving strategies. This study is meaningful in that it provided mathematically gifted children's problem solving procedures about open-ended problems and it made an attempt at concrete and practical case study about classes fur gifted children while most of studies on education for gifted children in this country focus on the studies on basic theories or quantitative studies.

• Applied Chemistry for Engineering
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• v.3 no.3
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• pp.412-421
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• 1992

The superconducting thin films have shown a growing possibility for practical application in microelectronic fields in recent years. In this study, the high Tc superconducting Y-Ba-Cu-O thin films were prepared on various substrates by chemical vapor deposition method using organic metal chelates of $Y(thd)_3$, $Ba(thd)_2$, and $Cu(thd)_2$ as source materials. The deposition reactions were carried out on single crystalline MgO(100), YSZ(100), $SrTiO_3(100)$, and polycrystalline $SrTiO_3$ substrates. Deposition thickness of thin films was linearly increased with the increase of deposition time. It turned out that the Y-Ba-Cu-O thin films on MgO(100), YSZ(100), and $SrTiO_3(100)$ single crystal substrates showed superconductivities above liquid nitrogen temperature($T_{c,onset}=87{\sim}89K$, $T_{c,zero}=85{\sim}86K$), but the one on polycrystalline $SrTiO_3$ substrate did not.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.258-270
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• 2016

This study was conducted to test the green-tide mitigation technique in the lower part of the Sook Stream (Chusori) of Daecheong Reservoir from June 27 to August 24, 2014. And the effects were compared with weekly monitoring result of the watching station of the algae alert system (AAS) as well as test beds reach. The green-tide in a test bed was begun from the upstream, and it was gradually transferred and spread toward the downstream by the hydrological factors. The total amount of algae removed by algae removal device during the test period was 33,920 kg, and solids dewatered by natural gravity was 8,480 kg. Also chlorophyll-a content was 2.83 kg, the number of blue-green algae cells was equivalent to $78.6{\times}10^{14}$ cells. Compared with the results of the watching station of AAS, the pre-concentrate removal work in the outbreak waters was able to suggest the possibility of green-tide mitigation. In addition, an effective management of the green-tide was required spatial and temporal occurrence information and practical device technology. Particularly, the optimal timing of algae removal in the river-reservoir hybrid system was recommended at times before the monsoon rainy season and reached the lowest water level.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.4 no.2
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• pp.77-87
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• 1986

As for the deformation measurement of structure, there are many controversial points in using the methods by the strain guage, inclinometer, bial guage, and geodetic method because of the difficulty of instrument setting and the problem in the degree of accuracy of the results as well as in the economical aspect. Therefore, to verify the superiority of the Close- Range Photogrammetry method for the structural deformation measurement, the result of load deformation on the model structure, which was made using the Close-Range Photogrammetry method was compard with the results which was made using the methods of dial guage, precision level, and triangulation. In addition to that, to consider the general problem which would happen when C. R. P method was applied to the practical structure. The elements of C. R. P method like camera rotation angle ($\psi$,$\omega$), exposure elevation (Z$_{L}$), and angle of inclined base line ($\theta$) were experimented, and their specificities were reconsidered. As a result, the application of C. R. P method to the general structure is expected to be increased not only in the aspect of accuracy but in the economical aspect.t.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.582-588
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• 2001

To control the growth of Salmonella on raw chicken supplied in food service, they were isolated and analysed for their physiological characteristics. Total viable microbe counts under the skin of the chicken amounted to 10% of numbers on their skin. Fifty one of Salmonella were isolated and identified from 75 chicken carcass samples. About 70% of the isolates showed resistance to more than four antibiotics, which indicated very high resistance among the strains ever reported in Korea. Lactic acid and trisodium phosphate(TSP) as sanitizing agent were applied to the Salmonella spp. isolates by agar diffusion method. The resistance by isolates to those sanitizing agents was compared with type strains of S. typhimurium ATCC 14028, S. typhimurium ATCC 12023, S. heidelberg and S. enteritidis. The isolates showed similar or less resistance to the type strains as for the lactic acid. However, as for trisodium phosphate known recently as a good sanitizer, 50% of the isolates showed more resistant compared with the type strains. Also, the treatment time and regeneration medium affected significantly the resistance of the isolates, which indicates that more careful test might be needed for TSP's practical application to raw chicken. Therefore, From the results, it is suggested that antibiotic treatment during breeding broiler and contamination after slaughtering should be minimized along with careful use of sanitizing agent in order to ensure more safe raw chicken supply.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3286-3291
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• 2014

A study on the crack protection and thermal insulation properties of the expanded perlite inorganic composites was performed. Mixed expanded perlite with a water glass was stabilized for 24 hrs at room temperature in the mold and, thereafter, converted into a massive foamed body through complete drying process at $150^{\circ}C$. Aluminum phosphate and micron size mica powder were used as a reaction accelerator and a stabilizer for thermal crack, respectively. Especially, use of mica exhibited a remarkable effect on the protection of thermal crack at higher temperature over $500^{\circ}C$, and thermal conductivity of the composites was enhanced with higher perlite contents, showing ca. 0.09 W/mK for the sample of 100/200/10/1.5 water glass/perlite/mica/Al phosphate by weight. A severe dimensional deformation of the composite materials was observed over $600^{\circ}C$, however, showing a temperature limitation for a practical application. The facts were considered as the results from the glass transition temperature of the water glass, of which main component is sodium silicate.

• The Journal of Industrial Distribution & Business
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• v.10 no.10
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• pp.35-44
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• 2019

Purpose - This study focuses on the continuance intention of O2O fresh agricultural products e-commerce. By literature review, this paper looks through the classical theories which are often applied to study use behavior and continuance intention on the electronic commerce area. Ultimately based on the expectancy theory, Technology acceptance model, success model as well as trust model, a model of the continuance intention of fresh products O2O electronic commerce application is established. Research design, data, and methodology - Among users Chinese consumers have been chosen who have use experience as the research objects. From October 2, 2018 to November 2, 2018, 685 questionnaires in total were collected by the online release and collection. Expect for the negative questionnaires, the remaining 650 pieces of data are statistically analyzed. The collected data were firstly be analyzed by SPSS Ver. 25 on its frequency, reliability and exploratory factors. Then AMOS Ver. 25 is applied to the Confirmatory Factor Analysis, Discriminant Validity and hypothesis testing of the Structural Equation Modeling. Finally, the following research conclusions could be obtained from the hypothesis testing. Results - Firstly, in the extended IS model, quality factor for hypothesis testing, service quality, information quality and delivery quality have obviously present positive influences on satisfaction respectively. Secondly, in the hypothesis testing part of ECM-ISC model and UTAUT model, all hypotheses have presented accepted results. Especially from expectation confirmation to usefulness perception, the influence factor achieves 12.603, In the hypothesis of continuance intention, the influence factor of social influence on continuance intention is 7.748 and also it is the most remarkable one. Conclusions - The results show that the service quality of O2O fresh agricultural products e-commerce has the greatest impact on satisfaction, while the perceived usefulness of consumers has the most significant impact on O2O fresh agricultural products for sustainable use intention. This thesis makes up for the blank of O2O fresh food e-commerce for sustainable use intentions, and provides a theoretical basis for consumers' sustainable use behavior, and practical enlightenment for the sustainable development of O2O fresh agricultural products e-commerce.