• Journal of Science and Technology Studies
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• v.1 no.1 s.1
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• pp.105-122
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• 2001

The purpose of this study is to understand how a teacher's teaching can be changed while he or she teaches the same contents in different classes. The qualitative research method was used in this study. Data were collected from classroom observations, several in-depth interviews, and stimulated-recall interviews after each class. All the data were transcribed and analyzed interpretively, and then, the results of the analysis were checked by each participating teacher. The results are as follows: First, changes appeared in each class in terms of the teaching items, tools, sequence, and time, even though the same teacher taught the same contents. It showed that the teacher's teaching practice changed immediately and intuitively in class. Second, teachers tried to implement "exploratory teaching" or "move-testing teaching" to address the emerging problems during their teaching. They then reflected on and modified their own teaching. This type of change, which happened during the teaching practice, can be an example of "Reflection-in-practice." Thus, the results of this study can provide helpful insights into how teachers might adapt and reflect in their teaching. It suggests that teachers need to recognize their subconscious teaching changes and learn "Reflection-in-practice."

• Journal of Science and Technology Studies
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• v.14 no.2
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• pp.85-125
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• 2014

This paper explores what we call 'the problem of undone social science' by examining the lack of interests in the social, ethical, and legal issues of synthetic biology among social scientists in Korea. This new field of science, which has emerged in the twenty-first century with the promise of solving future problems of energy, food, and disease in the world, has also created a considerable degree of anxiety over the issues of bioethics, biosafety, and biosecurity. From its beginning, therefore, researchers of synthetic biology in Europe and the U.S. have sought to engage social scientists in their projects. Yet scientists and social scientists in Korea have shown no sign of working together to deal with both potential benefits and risks of synthetic biology. Why this silence? What strategic moves would be needed to overcome the structural barrier for their collaboration? Surveying the diverse methodologies developed during and after ELSI (ethical, legal, social implications) experiments, this paper aims to provide three suggestions that might make possible mutually profitable and continuously stimulating dialogues between the two worlds of science and social science: first, institutionalize the ELSI studies on any newly emerging science and technology of concern; second, explore diverse post-ELSI methodologies experimented elsewhere and develop ones that might be applicable best to the Korean situation; and third and perhaps most important, create an intellectual space and a lawful protection for social scientists to exercise their research freedom at the reasonable level and receive a fair review by their peers, not solely by funding agencies and scientific organizations.

• Korean Journal of Poultry Science
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• v.20 no.4
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• pp.217-231
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• 1993

Due to the increased awareness on the relationship between high cholesterol intake and cardiovascular disease, the development of low cholesterol eggs and egg products are necessary at the present time. Largely, two approaches are possible to develop low cholesterol eggs. The first approach is the production of low cholesterol eggs by altering feeds of layers, by administering drugs, by genetic selection of strains and breeds, and by management of laying cycle, age and egg size. The second approach is to manufacture low cholesterol eggs technically treated with adsorbant, solvent, enzyme, edible oil and supercritical fluid. Both approaches have their own pros and cons, respectively, as far as the cholesterol removal rates, the easeness of process, and the economic reasons are concerned. The low cholesterol egg production is quite labor-intensive and has relatively low cholesterol removal rate(30∼50％ ) compared to that of chemically treated eggs. On the other hand, the low cholesterol eggs treated with chemicals have a very high cholesterol removal rate (80∼90％) but some of the methods are not completely safe as food processing purposes due to the residual chemicals and the sensory quality is not as good as the low cholesterol eggs without chemical treatment. Therefore, further studies must be conducted to improve the sensory quality of low cholesterol eggs and to eliminate fear about the harmfulness using low cholesterol eggs.

• Korean Journal of Plant Resources
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• v.21 no.1
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• pp.1-4
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• 2008

The clonal variation in female flowering was studied in Larix leptolepis clone bank, consisting of 116 clones, for three years. The between-year variation was large; i.e. the percentage of flowering grafts and average number of flowering per graft were $28.4{\sim}67.2$ and $9{\sim}176$, respectively. Differences in flowering abundance among clones were large and statistically significant in all the years studied. The variance of flowering abundance among clones was increased when flowering was poor. The average of broad-sense heritability of flowering abundance was 0.52. The genetic gain(%G) was estimated at 57.4% when the upper 30% clones were selected. The clonal stability of flowering abundance was compared using average number of flowering and coefficient of variance value of each clone. The clones such as Gyeonggi 9(29), Kangwon 37(137), Chungnam 6(46), Chungnam 14(414), R11, R8 showed abundant flowering and high stability.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.9
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• pp.351-360
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• 2018

The LWR (Locally Weighted Regression) model, which is traditionally a lazy learning model, is designed to obtain the solution of the prediction according to the input variable, the query point, and it is a kind of the regression equation in the short interval obtained as a result of the learning that gives a higher weight value closer to the query point. We study on an incremental ensemble learning approach for LWR, a form of lazy learning and memory-based learning. The proposed incremental ensemble learning method of LWR is to sequentially generate and integrate LWR models over time using a genetic algorithm to obtain a solution of a specific query point. The weaknesses of existing LWR models are that multiple LWR models can be generated based on the indicator function and data sample selection, and the quality of the predictions can also vary depending on this model. However, no research has been conducted to solve the problem of selection or combination of multiple LWR models. In this study, after generating the initial LWR model according to the indicator function and the sample data set, we iterate evolution learning process to obtain the proper indicator function and assess the LWR models applied to the other sample data sets to overcome the data set bias. We adopt Eager learning method to generate and store LWR model gradually when data is generated for all sections. In order to obtain a prediction solution at a specific point in time, an LWR model is generated based on newly generated data within a predetermined interval and then combined with existing LWR models in a section using a genetic algorithm. The proposed method shows better results than the method of selecting multiple LWR models using the simple average method. The results of this study are compared with the predicted results using multiple regression analysis by applying the real data such as the amount of traffic per hour in a specific area and hourly sales of a resting place of the highway, etc.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.259-259
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• 2016

반도체 산업 전반에 걸쳐 이루어지고 있는 연구는 소자를 더 작게 만들면서도 구동능력은 우수한 소자를 만들어내는 것이라고 할 수 있다. 따라서 소자의 미세화와 함께 트랜지스터의 구동능력의 향상을 위한 기술개발에 대한 필요성이 점차 커지고 있으며, 고유전(high-k)재료를 트랜지스터의 게이트 절연막으로 이용하는 방법이 개발되고 있다. High-k 재료를 트랜지스터의 게이트 절연막에 적용하면 낮은 전압으로 소자를 구동할 수 있어서 소비전력이 감소하고 소자의 미세화 측면에서도 매우 유리하다. 그러나, 초미세화된 소자를 제작하기 위하여 high-k 절연막의 두께를 줄이게 되면, 전기적 용량(capacitance)은 커지지만 에너지 밴드 오프셋(band-offset)이 기존의 실리콘 산화막(SiO2)보다 작고 또한 열공정에 의해 쉽게 결정화가 이루어지기 때문에 누설전류가 발생하여 소자의 열화를 초래할 수 있다. 따라서, 최근에는 이러한 문제를 해결하기 위하여 게이트 절연막 엔지니어링을 통해서 누설전류를 줄이면서 전기적 용량을 확보할 수 있는 연구가 주목받고 있다. 본 실험에서는 high-k 물질인 Ta2O5와 SiO2를 적층시켜서 누설전류를 줄이면서 동시에 높은 캐패시턴스를 달성할 수 있는 게이트 절연막 엔지니어링에 대한 연구를 진행하였다. 먼저 n-type Si 기판을 표준 RCA 세정한 다음, RF sputter를 사용하여 두께가 Ta2O5/SiO2 = 50/0, 50/5, 50/10, 25/10, 25/5 nm인 적층구조의 게이트 절연막을 형성하였다. 다음으로 Al 게이트 전극을 150 nm의 두께로 증착한 다음, 전기적 특성 개선을 위하여 furnace N2 분위기에서 $400^{\circ}C$로 30분간 후속 열처리를 진행하여 MOS capacitor 소자를 제작하였고, I-V 및 C-V 측정을 통하여 형성된 게이트 절연막의 전기적 특성을 평가하였다. 그 결과, Ta2O5/SiO2 = 50/0, 50/5, 50/10 nm인 게이트 절연막들은 누설전류는 낮지만, 큰 용량을 얻을 수 없었다. 한편, Ta2O5/SiO2 = 25/10, 25/5 nm의 조합에서는 충분한 용량을 확보할 수 있었다. 적층된 게이트 절연막의 유전상수는 25/5 nm, 25/10 nm 각각 8.3, 7.6으로 비슷하였지만, 문턱치 전압(VTH)은 각각 -0.64 V, -0.18 V로 25/10 nm가 0 V에 보다 근접한 값을 나타내었다. 한편, 누설전류는 25/10 nm가 25/5 nm보다 약 20 nA (@5 V) 낮은 것을 확인할 수 있었으며 절연파괴전압(breakdown voltage)도 증가한 것을 확인하였다. 결론적으로 Ta2O5/SiO2 적층 절연막의 두께가 25nm/10nm에서 최적의 특성을 얻을 수 있었으며, 본 실험과 같이 게이트 절연막 엔지니어링을 통하여 효과적으로 누설전류를 줄이고 게이트 용량을 증가시킴으로써 고집적화된 소자의 제작에 유용한 기술로 기대된다.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.7-11
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• 2004

This study was carried out to establish a new breeding scheme which is connected with conventional breeding method and anther culture method. To develop a herbicide resistant and direct seeding rice, $F_1$ plants were subjected to anther culture and regenerated plants from 5 crosses were studied to confirm the introduction of bar gene. After PCR analysis, we selected 227 plants which were carrying herbicide resistance gene (bar) out of 1,508 regenerated plants from anther culture. Among 169 $A_2$ lines carrying herbicide resistant gene from 5 crosses including YR23235 (Dongjin Ds3(Ba $r^{R}$)/ Milyang165), 42 lines that had superior agronomic characters were selected for further research. Among them, YR23235Acp79 which showed herbicide resistance, direct seeding adaptability and superiority in major agronomic characters was named Milyang 204. This breeding scheme proved that the anther culture of $F_1$ plants crossed between transformant and cultivar or transform ant alone could be utilized in breeding programs for a rapid progeny fixation and development of a variety.y.

• Journal of Mushroom
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• v.4 no.1
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• pp.1-32
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• 2006

According to UPOV (International Union for Protection of New Varieties of Plants), mushroom spawn market have to be opened by the year 2009. Number of commercial strains distributed by the year 2005 were 179 of 24 species of edible and medicinal mushrooms. Only nine strains of oyster mushrooms were registered as protected variety, which is not compatible with those recorded in other advanced countries. Meaning of spawn in broad sense contains commercial strains. Development of commercial strains faces two main problems in Korea : One is the complicated genetic patterns and sexuality of mushroom species, and the other is expensive experimental equipments and fruiting body growing houses. Resolution of these problems leads to development of mushroom strains. This could be achieved as follows; genetic resources collection and assessment, molecular characterization of useful genetic characters, development of new commercial strains by hybridization using typical genetic resources, strengthening of breeding research using "Mushroom Breeding Group", management of spawn research company by consortium, foundation of mushroom general industry, promotion of consumption, and upgrade of competition ability for other countries. These points are under discussion.

• Journal of Life Science
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• v.14 no.5
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• pp.868-873
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• 2004

The efficient fermentative production of L-threonine fermentation was achieved by using Escherichia coli MT201, transformed a plasmid carrying pyruvate carboxylase gene. It is an attempt to supply oxaloacetate to the L-threonine biosynthetic pathway. In order to improve the L-threonine productivity of E. coli MT201, a plasmid pPYC which is an expression vector of the pyruvate carboxylase gene of Coryne-bacterium glutamicum, was introduced. When E. coli MT/pPYC was incubated with medium containing only glucose as a carbon source, both the cell growth and L-threonine production were reduced, compared to the results from fermentation of E. coli MT201. In order to circumvent this effect, we attempted the addition of a mixed carbon source, composed of glucose and sodium citrate at a ratio of 1.5:3.5. It was shown that L-threonine production and cell growth (OD660) with E. coli MT/pPYC reached up to 75.7 g/l and 48, respectively, at incubation for 75 hr under fed-batch fermentation conditions. It is assumed that overproduction of L-threonine by anaplerotic pathway leads unbalance of TCA cycle and sodium citrate might playa role to recover normal TCA cycle.

• Korean Journal of Plant Taxonomy
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• v.32 no.4
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• pp.383-396
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• 2002

RAPD analyses were compared for 17 taxa of Korean Iris including the subgenus Sisyrinchium and Belamcanda. Eighty scorable RAPD markers were formed from the PCR reactions using 10 random oligoprimers. In this systematic analyses which used neighbor-joining methods including bootstrapping analyses with genetic coefficients, the Korean Iris were divided into three subgenera (Limniris, Crossiris, Pardanthopsis), or two genera (Limniris, Pardanthopsis). The molecular data agree with the previous classification system that recognized two sections and six series for the subgenus Limniris because the subgenus is comprised of four clades in the RAPD analyses. According to the molecula data, the series Chinensis should be divided into two groups. The minutoaurea group is composed of I. koreana, I. odaesanensis, and I. minitoaurea, while the rossi group is comprised of two varieties of I. rossi. The series Tripetalae is closely allied with the series Sibiricae, whereas the series Ensatae is recognized as a sister group to the series Ruthencae. The molecular phylogeny, which was based on RAPD analysis, for the most part agreed with the data proposed by previous authors. This is because the basis of morphological and ITS sequence data suggests that the RAPD markers should be very useful in addressing phylogenetic questions about the genus Iris.