• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.6
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• pp.237-241
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• 2014

We investigated the optimal etching conditions and properties of the surface change due to molten KOH/NaOH chemical wet etching using an AlN wafer which has been put to practical use in the present study. Results were observed using a scanning electron microscope after 5 minutes etching at $350^{\circ}C$, was found to have a surface form of the respective other Al-face, the N-face. In particular, etch-pit in the form of a hexagon, which is observed in the Al-face appeared, It was calculated at $2{\times}10^6/cm^2{\sim}10^{10}/cm^2$ dislocation density. In the case of N-face, lattice defects in the form of the hexagonal pyramids is formed. It was discovered that in order to observe the orientation of the wafer, which corresponds to the C-axis direction of the resulting hexagonal AlN which was analyzed using XRD (0002) and is a state of being oriented in the (0004) plane. The Radius of curvature of AlN wafer was 1.6~17 m measured by DC-XRD rocking curve position.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.1
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• pp.1-5
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• 2009

In this study, we performed growth of InGaN/GaN multi quantum well (MQW) structures on semi-polar (1-10]) GaN facet on 8-degree off oriented stripe patterned (100) Si substratcs by MOVPE. The structural and optical properties of the InGaN/GaN multi quantum well (MQW) structures grown on (1-101) GaN stripe depend on $NH_3$ flow rate, TMI flow rate and growth temperature are characterized by cathodoluminescence (CL) and scanning electron microscopy (SEM). With the decrease of $NH_3$ flow rate, the threading dislocation of (1-101) GaN is considerably reduced. We could control the transition wavelength of InGaN/GaN MQW structures from 391.5 nm to 541.2 nm depend on the growth conditions.

• Journal of The Korean Association of Information Education
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• v.18 no.2
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• pp.295-306
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• 2014

A form of life is changed rapidly through development of ICT. And we need information ethics as a new norm of information-oriented society. The effect of information ethics can be maximized by education. Therefore, a new curriculum is demanded by new technology and circumstance. Korea Association of Information education has studied a new curriculum and suggested a new plan that contents of information education classified by 'Software', 'Computer System' and 'Convergence Activities' sections. And the 'Convergence Activities' section is composed of 'Information Ethics', 'Productivity Tools' and 'Robot'. In this paper, we studied on learning elements of the 'Information Ethics' of first grade to ninth grade. We analysed the domestic and foreign curriculum, research results and new issues about information ethics and selected the learning elements about information ethics. We nextly suggested the achievement goals, teaching-learning methods and evaluation methods of information ethics. We expect that the learning elements we suggested about information ethics will contribute to deal with wisely information dysfunction and to training correct talented individuals.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.3
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• pp.132-138
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• 2003

A stoichiometric mixture for $CdIn_2Te_4$ single crystal was prepared from horizontal electric furnace. The $CdIn_2Te_4$ single crystal was grown in the three-stage vertical electric furnace by using Bridgman method. The $CdIn_2Te_4$ single crystal was evaluated to be tetragonal by the power method. The (001) growth plane of oriented $CdIn_2Te_4$ single crystal was confirmed from back-reflection Laue patterns. The carrier density and mobility of $CdIn_2Te_4$ single crystal measured with Hall effect by van der Pauw method are $8.61\times 1016 \textrm {cm}^{-3}$ and 242 $\textrm{cm}^2$/V.s at 293 K, respectively. The temperature dependence of the energy band gap of the $CdIn_2Te_4$ single crystal obtained from the absorption spectra was well described by the Varshni's relation, $1.4750ev - (7.69\times10^{-3})\; ev/k)\;T^2$/(T + 2147k).The crystal field and the spin-orbit splitting energies for the valence band of the $CdIn_2Te_4$ single crystal have been estimated to be 0.2704 eV and 0.1465 eV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the $\Delta$so definitely exists in the $\Gamma_7$ states of the valence band of the $CdIn_2Te_4$ single crystal. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1-} B_{1-}$ and Cl-exciton peaks for n = 1.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.4
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• pp.318-331
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• 1995

The c - axis oriented single crystal of $LiNbO_3$ and $LiNbO_3$ : 5mol%MgO was success-fully grown by Floating zone method using halogen lamp as a heat source. The effects of the sintering condition of the feed rod and the atmosphere gas during the crystal growth on the be havior of the feed rod/melt interface were studied for growing crystal with the high quality, and then, the optimum growth conditions were determined by studying the experimental param eters, such as gas flow rate, pulling rate, rotation speeds of the feed rod and the seed. The grown crystals were analyzed using the chemical etching to observe the tch pattern and the ICP (Inductively Coupled Plasma) to determine the composition uniformity and the impurity content of Fe. The effects of additive (5 mol % MgO) on the transmittance and refractive index was, also, analyzed. In order to compare the nonlinear optical oharacteristics of $LiNbO_3$ with those of the other optical materials, the nonlinear optical refractive index ($n_2$) was calcu l lated using the measured refractive index.

• Journal of the Korean Society of Costume
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• v.53 no.1
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• pp.35-48
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• 2003

The primary goal of this study is to define the future image of modern fashion. By review of many references, this study has examined predictable future in common, various researches on future, and futurism that appeared from art history. This study has also identified the trend of future image and the properties of the image in terms of fashion as well. The purpose of this study is defined as future image of modern fashion. First of all. through a large literature, this study is to examine general future and the study of future, to investigate futurism appears from art history. and to identify the trend of future image and the properties of the image in terms of fashion. The main results of this study include : 1) General future means forthcoming sometime or a state of life at that time, and future is not drawing near naturally in accordance with the passage of time. The future is developed according as which the owners of time have independent meaning and what they select. 2) The futurism had started with the background based on Darwins and Einsteins scientific theories and Bergsons and Nietzsches philosophical thoughts, which was then established by Marinettis Futurism Statement and Dynamism Theory of Umberto Boccionio, Giaomo Balla, Luigi Russolo and Gino Severini. As the purpose of futurism is to represent the dynamism of machinery and the beauty of speed, it has been developed toward op art and kinetic art including video art, laser art, and holography. 3) Fashion style and trend of futurism from the beginning of 20th century up to now can be defined as follows : Firstly futurism fashion represented by loud colors and geometric pattern appeared from 1910s to 1930s in the first place. Secondly, or art fashion and kinetic fashion appeared in 1960s due to the influence of op art and kinetic art which were developmental arts of futurism paintings. Space Look and Cosmo Corps Look that were designed by Andre Courreges, Pierre Cardin, Rudi Gernreich and Paco Rabanne, were also the trend of future image fashion. Thirdly, various materials and techniques developed this future image fashion in 1980s, and Glitter Look and Collage Look were its representative style. Fourthly, in 1990s, human beings dreamed the freedom of mind by human-oriented thought. and created the ecology of new concept mixed with technology due to anxiety on environmental destruction. which influenced on the advent of Zen style.

• Communications of Mathematical Education
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• v.26 no.2
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• pp.177-203
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• 2012

The purpose of this research was to look at whether small group drawing activities can be applied to learning content that combine mathematics and art, by analyzing the changes in $10^{th}$ grade students' interests in mathematics and particular features of their strategic thinking that were reflected in small group drawing activities using graphs and inequations. The results of the study are as follows: 1. The small group drawing activity using graphs and inequations demonstrated that students interests in mathematics could experience positive changes. 2. The small group drawing activity using graphs and inequations was effective in stimulating the students' strategic thinking skills, which are higher level thinking activities necessary for creating problem solving. As the students went through the whole process of accomplishing a complete goal, the students engaged in integrated thinking activities that brought understandings of basic graphs and inequations together, and were also found to use such higher level thinking functions needed in achieving creative problem solving such as critical thinking, flexible thinking, development-oriented thinking, and inferential thinking. 3. The small group drawing activity using graphs and in equations could be expected to constitute learning content that integrate mathematics and art, and is an effective solution in boosting students' strengths in mathematics by way of activities that consider students' unique cognitive and qualitative peculiarities and through integration with art.

• Information Systems Review
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• v.11 no.2
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• pp.147-167
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• 2009

As global climate changes, the interest in environmental crisis is increasing and a number of international agreements and regulations against this crisis are being established. Global information technology(IT) corporations are building their own pro-environmental green IT strategies to cope with the regulatory measures. Green IT broadly refers to pro-environmental technologies designed to replace hazardous materials, maximize energy effectivity, and find alternative energies. In the current stage of the IT industry development, Green IT specifically refers to the technologies that deal with the server heat generation and the energy reduction in data center. This study defines the concept of Green IT and reviews its origin and necessity. Then, it examines the issues regarding Green IT industry in Korea as well as other countries and compares the Green IT strategies developed in each country. Reviewing the recent development of IT and data center market enables us to see that overall Green IT strategies focus on the establishment of Green Internet Data Centers. Therefore, this study analyzes the cases in which some domestic and foreign corporations introduced Green Data Centers in order to examine the protocol and legal requirements for building Green IT, the aspects of environmental evaluation and design, and specific strategies for launching Green IT strategies and its future assignments. The conclusions of this study are as follows. First, to introduce Green Data Center as a strategy to build Green IT, the government and corporations should cooperate with each other. Partial introduction at the initial stage is desirable because, through the process, mutual trust between the two parties can be built more smoothly. Second, CEO's determination to build Green IT and continue its operation is indispensable. CEO's are required to have clear understanding as to why Green IT needs to be built and how it should be constructed. Those who initiate the construction of Green Data Center for Green IT need to know the definition and necessity of Green IT while at the same time understanding the implicit meanings of Green IT. They also need to be aware of future-oriented values of Green Data Center and readjust their corporate business activities in the pro-environmental direction. Finally, not only the CEOs' pro-environmental activities but also the change of mind on the part of all corporate employees is required to realize Green IT. It should be remembered that pro-environmental Green IT starts with minor activities.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.2
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• pp.153-163
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• 2008

Medical imaging modalities to image either anatomical structure or functional processes have developed along somewhat independent paths. Functional images with single photon emission computed tomography (SPECT) and positron emission tomography (PET) are playing an increasingly important role in the diagnosis and staging of malignant disease, image-guided therapy planning, and treatment monitoring. SPECT and PET complement the more conventional anatomic imaging modalities of computed tomography (CT) and magnetic resonance (MR) imaging. When the functional imaging modality was combined with the anatomic imaging modality, the multimodality can help both identify and localize functional abnormalities. Combining PET with a high-resolution anatomical imaging modality such as CT can resolve the localization issue as long as the images from the two modalities are accurately coregistered. Software-based registration techniques have difficulty accounting for differences in patient positioning and involuntary movement of internal organs, often necessitating labor-intensive nonlinear mapping that may not converge to a satisfactory result. These challenges have recently been addressed by the introduction of the combined PET/CT scanner and SPECT/CT scanner, a hardware-oriented approach to image fusion. Combined PET/CT and SPECT/CT devices are playing an increasingly important role in the diagnosis and staging of human disease. The paper will review the development of multi modality instrumentations for clinical use from conception to present-day technology and the application software.

• Journal of Animal Environmental Science
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• v.8 no.1
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• pp.43-53
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• 2002

The aim of the study is to describe the fate and transformation of nitrogen in grassland ecosystems. In the growing season from 1987 to 1993, 2 growing farmer in south Germany were studied the yield and nutrient balance of reduced input slurry application. The study includes 3 different slurry application levels. The levels are conventional slurry application, reduced slurry application, without slurry application. These levels are studied at 2 different experimental farms. The forage yield of zero slurry application plot has 14∼44% of the conventional slurry application, while the yield in the reduced slurry plot is only 0∼14% lower than that in the conventional slurry plot. The kalium and phosphorus contents of forage were tend to decrease with reduced slurry application N-uptake was increasing with the increase of slurry application level. The N-uptake of zero slurry plots was lower 40∼65% of the conventional plot, while in the reduced plot was only 6∼16% lower than in the conventional plot. The N-balance shows negative figures on all plots. The N-uptake in experiment site A was only a little bit more than the N-fertilizer plot, while in site experiment B the N-uptake is 2 to 3 times higher than the N-application amount of slurry.