• International Journal of Human Ecology
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• 제5권1호
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• pp.23-34
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• 2004

This paper outlines the findings of a consumer survey conducted in 1996 and 2001 by the University of Bonn, Germany, across 15 European countries. The survey involved a sample of 3,300 respondents in 1996 and around 11,000 respondents in 2001, throughout all 15 EU countries. Children and adolescents between the ages of 10 and 17 were surveyed on their consumption habits and their attitudes towards the environment. The paper outlines the key findings on "the process of socialization with money". Children come to appreciate the importance of money even before their first day at school. Even young children know you sometimes need cash to fulfil dreams. But the chance to experiment with money for real only comes when children first receive pocket money, usually from their parents. Later, in adolescence, consumer pressure starts to make an impact and it becomes more difficult to make ends meet. Spare time or holiday jobs help top up pocket money and enable adolescents to keep out of debt. This paper reports on a long term comparative study throughout the European Union among children and adolescents, analysed by country, age group and gender. The paper discusses the places young consumers can turn to in trying to fulfil their growing consumer needs. It also examines how much money is at their disposal. It then concludes by considering the influence of "financial socialization" on how young people deal with money.

• East Asian mathematical journal
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• 제30권4호
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• pp.509-526
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• 2014

The mathematics has moved toward the independence from unit. However, is this tendency also kept up in teaching and learning mathematics? This study starts from this question. We have illuminated this question in respects of a character of unit operation, an essential probability of unit operation and a didactical application of unit. As results, addition and subtraction are operations on identical objects and the result of operation does not also get out of operation's object. On the other hand, multiplication and division are operations on both identical objects and different objects. And the result of operation can generate new unit. We proposed a hypothesis which multiplication and division are transcendental operations from this analysis. The unit operation is not possible essentially. It seems only like unit operation is possible superficially by operational definition on unit. We could discuss on a didactical application of unit from above analysis. And we could deduct implications that the direction of developing mathematic does not necessarily match with the direction of teaching and learning mathematics.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1996년도 제10회 식물생명공학심포지움 고등식물 발생생물학의 최근 진보
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• pp.10-18
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• 1996

Recently, we have reported a rice MADS-box gene, OsMADS1, as a molecular factor triggering flower formation; this has been well studied in a heterologous system (Chung et al., 1994). In order to study whether the OsMADS1 homolog exists in other plant species, the OsMADS1 cDNA was used as a probe to screen a tobacco cDNA library, and a potential homolog, NtMADS3, was isolated. Sequence analysis revealed that the gene shares 56.1% identity in whole amino acids with OsMADS1. Like OsMADS1, the NtMADS3 gene starts to express at a very early stage of flower development, and the expression continues up to flower maturation. In the tobacco flower, the gene is expressed in whorl 2,3 and 4, corresponding to the petal, stamen, and carpel, respectively. Upon ectopic expression in the homologous system, NtMADS3 caused a trasition from inflorescence shoot meristem into floral meristem, reducing flowering time dramatically. These phenotypes strongly suggest the NtMADS3 gene is the OsMADS1 homolog of tobacco. Hybrids between the OsMADS1 and the NtMADS3 plants were also generated. The hybrids flowered even earlier than these two transgenic plants. The detailed studies are discussed here.

• 한국세라믹학회지
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• 제44권11호
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• pp.622-626
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• 2007

Graphite is widely used in electronic industry due to its excellent electrical and thermal properties. However, graphite starts to oxidize around $400^{\circ}C$ that seriously degrades its properties. SiC coating can be applied to graphite foam to improve its high temperature oxidation resistance. In this research, SiC coating on graphite foam was made via preceramic polymer using a polyphenylcarbosilane. 20% of polyphenylcarbosilane in hexane solution was coated onto graphite by dip coating method. Thermal oxidation was carried out at $200^{\circ}C$ for crosslink of the preceramic polymer and the sample were pyrolysized at $800^{\circ}C{\sim}1200^{\circ}C$ under nitrogen to convert the preceramic polymer to SiC film. The microstructure of the SiC coating after pyrolysis was investigated using FESEM and oxidation resistance up to $800^{\circ}C$ was evaluated.

• 한국항해항만학회지
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• 제33권7호
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• pp.477-482
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• 2009

In this paper the order picking problem in warehouses is considered, a topic which has received considerable attention from the international academic body in recent years. The order picking problem deals with the retrieval of order items from prespecified locations in the warehouse, and its objective is usually the minimization of travel time or travel distance. Hence, a well-thought order picking policy in combination with an appropriate storage policy will enhance warehouse efficiency and reduce operational costs. This paper starts with a literature overview summarizing approaches to routing order pickers, assigning stock-keeping units to pick locations and designing warehouse layouts. Since the layout design might affect both storage and routing policies, the three factors are interdependent with respect to order picking performance. To test these interdependencies, a simulation experiment was set up, involving two types of warehouse layout, four types of storage policy, five well-known heuristics and five sizes of order picking list. Our results illustrate that from the point of view of order picking distance minimization it is recommended to equip the warehouse with a third cross aisle, although this comes at the cost of a certain space loss. Additionally, we propose a set of most appropriate matches between order picking heuristics and storage policies. Finally, we give some directions for further research and recommend an integrated approach involving all factors that affect warehouse efficiency.

• 정보교육학회논문지
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• 제8권3호
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• pp.417-432
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• 2004

ICT의 급속한 발달은 정보 사회에 대한 논의를 넘어서 지식 사회에 대한 논의를 촉발시키며, ICT를 활용한 지식 창출 능력의 중요성을 강조하고 있다. 그러나 우리나라의 컴퓨터교육은 ICT에 대한 개념이나 방향 설정이 미비한 채로 그 활용만을 위주로 전개되고 있는 형편이다. 현행 컴퓨터교육은 ICT의 기계적인 활용이 강조될 개연성이 높기 때문에 지식 사회에서 요구되는 창조적 인간상 육성에 부합하기 힘든 한계를 가지고 있다. 본 연구는 이와 같은 문제의식에 따라 컴퓨터교육의 바람직한 방향을 제공하고자, 우리나라 컴퓨터교육의 현황과 논쟁을 살펴보고, 지식정보사회에서의 컴퓨터교육의 개념과 지평, 교과로서 컴퓨터교육의 필요성과 방향에 대해 고찰하였다.

• The Korean Journal of Ecology
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• 제26권3호
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• pp.115-121
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• 2003

Leaves of two-week old seedlings of tomato (Lycopersicon esculentum) were treated with various concentrations (0∼100 M) of $CdCl_2$ for up to 9 days and subsequent growth of seedlings, symptoms of oxidative stress and isozyme activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POX) were investigated. Compared with the non-treated control, Cd exposure decreased biomass but increased Cd accumulation, hydrogen peroxide production and lipid peroxidation as malondialdehyde (MDA) formation in leaves and roots. Further studies on the developmental changes of isozyme activities showed that Fe-SOD, Cu/Zn-SOD and one of three APX isozymes decreased and CAT and one of four POX isozymes increased in leaves, whereas Fe-SOD, one of three POX isozymes and two of four APX isozymes decreased and CAT increased in roots, showing different expression of isozymes in leaves and roots with Cd exposure level and time. Based on our results, we suggest that the reduction of seedling growth by Cd exposure is the oxidative stress resulting from the over production of $H_2O_2$ and the insufficient activities of antioxidant enzymes particularly involved in the scavenging of $H_2O_2$. Further, the decreased activities of SOD and APX isozymes of chloroplast origin, the increased activities of CAT and POX and high $H_2O_2$ contents with Cd exposure might indicate that Cd-induced oxidative stress starts outside chloroplast.

• Journal of Electrical Engineering and Technology
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• 제5권2호
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• pp.191-196
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• 2010

Power system restoration following a massive or complete blackout starts with energizing the primary restorative transmission system. During this primary restoration process, unexpected overvoltage may happen due to nonlinear interaction between the unloaded transformer and the transmission system. In the case of the Myanmar electric power system, there are so many wide outage experiences, including complete blackout cases, caused by 230kV line faults and so on. Consequently, Myanmar's system operators have been well trained to deal with wide blackouts. Howver, system blackout restoration has been conducted by relying on the experience of only a few specialists. So, more scientific analysis is required to meet the requirements necessary to ensure fast and reliable system restoration. This paper presents analytical results on the primary restorative transmission system of Myanmar, focusing on the problems during the early restoration process. Methodologies are presented that handle load pick-up, terminal voltage and the reactive capability limitation of black-start generators to compensate the Ferranti effect. Static and dynamic simulation with the PSSolution and EMTDC programs respectively for the six cases are performed in order to select the primary restorative transmission lines.

• 조명전기설비학회논문지
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• 제25권8호
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• pp.39-47
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• 2011

The motion of a conductive spherical particle under uniform electric field is investigated in order to find a suitable method for removing the conducting solid impurities contained in liquid plastic. When the positive dc voltage applied to the upper electrode, the vertical up-and-down motion of a charged particle by electrostatic force is observed by a charge-coupled device (CCD) camera or a high-speed video camera. The experimental data of the static threshold voltage by which the particle starts to move toward the counter electrode in air or silicone oil are in good agreement with theoretical value. When the applied voltage is larger than the static threshold voltage, the particle motion pattern in silicone oil consists of four stages: upward motion, stopping at the upper electrode, downward motion and stopping at the lower electrode. The stopping motion on the electrode is thought to be caused by the liquid flow accompanied by the particle motion. The particle charge calculated by integrating the pulse current, which is generated by the charge exchange between the electrode and the particle, is approximately 0.1~0.25 times of the theoretical value. This study is expected to help understand the electric properties of microparticles in oil circuit breaker (OCB) and oil transformer and improve their performance and longevity.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2010년도 한국우주과학회보 제19권1호
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• pp.25.1-25.1
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• 2010

This talk outlines the current understanding of solar flares, mainly focusing on magnetohydrodynamic (MHD) processes. A flare causes plasma heating, mass ejection, and particle acceleration that generates high-energy particles. The key physical processes related to a flare are: the emergence of magnetic field from the solar interior to the solar atmosphere (flux emergence), formation of current-concentrated areas (current sheets) in the corona, and magnetic reconnection proceeding in current sheets that causes shock heating, mass ejection, and particle acceleration. A flare starts with the dissipation of electric currents in the corona, followed by various dynamic processes which affect lower atmospheres such as the chromosphere and photosphere. In order to understand the physical mechanism for producing a flare, theoretical modeling has been developed, in which numerical simulation is a strong tool reproducing the time-dependent, nonlinear evolution of plasma before and after the onset of a flare. In this talk we review various models of a flare proposed so far, explaining key features of these models. We show observed properties of flares, and then discuss the processes of energy build-up, release, and transport, all of which are responsible for producing a flare. We come to a concluding view that flares are the manifestation of recovering and ejecting processes of a global magnetic flux tube in the solar atmosphere, which was disrupted via interaction with convective plasma while it was rising through the convection zone.