• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.445-451
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• 2010

$TiO_2$ shows considerably efficient photoreaction activity under the ultraviolet range but it has disadvantage that there is no activity in the visible light range. In this study, it was tried to find a solution for the problem of this kind of photocatalyst by utilizing transition metal, which can show electronic transition with $TiO_2$ in the visible light area. Photocatalyst was prepared, which can have photocatalytic activity in the wide wavelength range, not only ultraviolet region but also visible light area and prevent the combination of electron and hole hindering the photoreaction. For this purpose, by using the ion exchange method, $TiO_2$ precursor and transition metal precursor were dipped into H typed strong acid ion-exchange resin. And two kind photocatalysts (Ti-M-SCM) in which transition metal and titanium dioxide coexist through the carbonization/activation process was prepared. Moreover, photolytic reaction under the wavelength 254 nm and 365 nm was performed for humic acid (HA) in the continuous reactor in order to estimate the efficiency of produced Ti-M-SCM.

• Journal of the Korean association of regional geographers
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• v.17 no.6
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• pp.710-725
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• 2011

The purpose of this study is to analyze both residential conditions and the resident impressions of the transition zone of central Daegu. The results drawn from a questionnaire survey of the residents are summarized as follows: 1) The proportion of people over the age of 60 living on a low income is high and consists mostly of retired citizens who have lived in the transition zone, in their own homes, for an extended length of time 2) The condition of infrastructure in the transition zone is very poor, however, despite the housing deterioration, the internal repair and maintenance of houses is more satisfactory than their external appearance. 3) Residential satisfaction received high ratings in every category except pollution and housing price. This response appears to stem from the easy commute of residents as well as the ready availability of facilities in the city center. 4) In terms of residential satisfaction, the residents can be divided into two groups. The first, with a high satisfaction rate, consists mainly of senior citizens who possess both personal homes and a stable living, having resided in the city center for most of their lives. The second, with a lower satisfaction rate, is composed mostly of younger residents who have lived temporarily in inexpensive rental homes. As a results, the residential area in the transition zone of central Daegu does not appear to be a problematic area like the slum of the West, but instead a stable settlement for its residents.

• Korean Journal of Biological Psychiatry
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• v.26 no.1
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• pp.22-31
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• 2019

Objectives Previous studies have revealed inconsistent results on amygdala volume in adult bipolar disorder (BD) patients compared to healthy controls (HC). Since the amygdala encompasses multiple subregions, the subtle volume changes in each amygdala nucleus might have not been fully reflected in the measure of the total amygdala volume, causing discrepant results. Thus, we aimed to investigate volume changes in each amygdala subregion and their association with subtypes of BD, lithium use and clinical status of BD. Methods Fifty-five BD patients and 55 HC underwent T1-weighted structural magnetic resonance imaging. We analyzed volumes of the whole amygdala and each amygdala subregion, including the anterior amygdaloid area, cortico-amygdaloid transition area, basal, lateral, accessory basal, central, cortical, medial and paralaminar nuclei using the atlas in the FreeSurfer. The volume difference was analyzed using a one-way analysis of covariance with individual volumes as dependent variables, and age, sex, and total intracranial volume as covariates. Results The volumes of whole right amygdala and subregions including basal nucleus, accessory basal nucleus, anterior amygdaloid area, and cortico-amygdaloid transition area in the right amygdala of BD patients were significantly smaller for the HC group. No significant volume difference between bipolar I disorder and bipolar II disorder was found after the Bonferroni correction. The trend of larger volume in medial nucleus with lithium treatment was not significant after the Bonferroni correction. No significant correlation between illness duration and amygdala volume, and insignificant negative correlation were found between right central nucleus volume and depression severity. Conclusions Significant volume decrements of the whole amygdala, basal nucleus, accessory basal nucleus, anterior amygdaloid area, and cortico-amygdaloid transition area were found in the right hemisphere in adult BD patients, compared to HC group. We postulate that such volume changes are associated with altered functional activity and connectivity of amygdala nuclei in BD.

• Journal of Science and Technology Studies
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• v.18 no.1
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• pp.219-265
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• 2018

Recently, interest in energy tranisition is rising. Energy transition requires active participation and cooperation of diverse stakeholders, including users / citizens, in that it requires not only changes in technological factors but also changes and coordination of various social factors. Living labs are attracting attention as one of the ways to do this. This article is a detailed analysis of the activities of the mini-PV living lab in the urban area from 2016 to 2017 at the Seoul, Sung Dae Goal. Through the Living Lab, mini PV DIY products, backup centers, local financial services, and the development of a variety of education and training strategies have been achieved. These activities and achievements were analyzed through questions raised on strategic, tactical, and operational levels, as well as through multi-level perspective and interaction between initiative, regime, and niche. In conclusion, this living lab activity confirmed the possibility of a 'transition lap' to solve social problems such as sustainability of energy production and utilization. In particular, it gained remarkable results in terms of the operational leves of transition management governance, that is, transition experiment, and it was also remarkable in that it was the initiative of citizens. However, it did not proceed without difficulty. In particular, structural problems such as the conflict between the flexibility inherent in living lab and the bureaucratic rigidity of the financial support organization have appeared. There was also a limitation that there was no 'transition field' on the strategic level necessary to replicate and expand strategic niches while spreading the knowledge gained from the transition experiment, forming the vision of transition.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2000.02a
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• pp.166-169
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• 2000

Usually, the critical current of jointed BSCCO tapes degrades quite a bit compared to the normal unjointed tape regions. It has been thought that the current redistribution around the jointed region is the main cause it. We experimentally found the linear voltage components around the jointed area, especially in the transition region, which suggests that the current redistribution around the jointed area is the main reason of the critical current degradations.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.841-842
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• 1988

For determination of black-out area and restoration area by an expert system for fault section estimation and power system restoration using information from circuit breakers, it is necessary that the recognition of system isolation state and a method of finding the change of system isolation state by the state transition of breakers in isolated system. This paper presents a method of resolving the above problem by rule-based approach.

• Macromolecular Research
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• v.12 no.1
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• pp.127-133
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• 2004

We have studied the surface micelle formation of polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) at the air-water interface. A series of four PS-b-P2VPs were synthesized by anionic polymerization, keeping the PS block length constant (28 kg/㏖) and varying the P2VP block length (1, 11, 28, or 59 kg/㏖). The surface pressure-area ($\pi$-A) isotherms were measured and the surface morphology was studied by atomic force microscopy (AFM) after Langmuir-Blodgett film deposition onto silicon wafers. At low surface pressure, the hydrophobic PS blocks aggregate to form pancake-like micelle cores and the hydrophilic P2VP block chains spread on the water surface to form a corona-like monolayer. The surface area occupied by a block copolymer is proportional to the molecular weight of the P2VP block and identical to the surface area occupied by a homo-P2VP. It indicates that the entire surface is covered by the P2VP monolayer and the PS micelle cores lie on the P2VP monolayer. As the surface pressure is increased, the $\pi$-A isotherm shows a transition region where the surface pressure does not change much with the film compression. In this transition region, which displays high compressibility, the P2VP blocks restructure from the monolayer and spread at the air-water interface. After the transition, the Langmuir film becomes much less compressible. In this high-surface-pressure regime, the PS cores cover practically the entire surface area, as observed by AFM and the limiting area of the film. All the diblock copolymers formed circular micelles, except for the block copolymer having a very short P2VP block (1 kg/㏖), which formed large, non-uniform PS aggregates. By mixing with the block copolymer having a longer P2VP block (11 kg/㏖), we observed rod-shaped micelles, which indicates that the morphology of the surfaces micelles can be controlled by adjusting the average composition of block copolymers.

• Communications of Mathematical Education
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• v.38 no.2
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• pp.121-144
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• 2024

This study analyzes how the academic achievement of students in Korea changes as they transition from 4th grade of elementary school to 2nd grade of middle school, considering that the 4th graders in the previous TIMSS cycle become 2nd graders in the next cycle. In particular, this study selects and compares the eight main countries in the TIMSS math evaluation (Korea, Singapore, Taiwan, Japan, USA, UK, Australia, and Russia) to analyze the trend of change in academic achievement of Korean students according to school grade transition. The trend of change in academic achievement of students was analyzed not only overall but also by content area (number, geometry and measurement, data representation (data and probability/data and probability), gender, and regional scale. The analysis focused on the average score and the proportion of students by achievement level. The results of the study are as follows. First, there was no significant change in the average score of Korean students' academic achievement as the school grade transitioned, but the achievement gap widened in terms of the proportion by achievement level. Second, there were differences in students' academic achievement by content area according to school grade transition, and the pattern differed depending on the evaluation cycle. Third, there was a significant gap in students' math academic achievement depending on gender and regional scale of school location. This study reveals that the achievement gap among students in our country widens as they transition between school levels. The gap is found to vary in terms of achievement level, math content area, student gender, and school location. To alleviate these disparities, more substantial research and support are proposed in addition to policy implementation by the government or provincial offices of education.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.149.2-149.2
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• 2007

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1915-1922
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• 2012

In this study, synthesis of mesoporous silica such as, SBA-15, MCM-41, MCM-48, KIT-6 according to various experimental conditions. The CMK(Carbon Mesoporous Korea) was synthsized by various mesoporous silica. Finally, the mesoporous transition metal structure synthesized using CMK structure. Nitrogen adsorption/ desorption, SEM, low angle X-ray diffraction were carried for analysis of each sample. The optimum synthesis condition of mesoporous transition metal structure derived from characteristic analysis. The SBA-15 is best precursor for synthesis of mesoporous transition metal structure. The surface area of copper mesorporous structure from CMK(SBA-15) is $225m^2/g$, pore diameter is 2.91nm by BET analysis.