• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.147-148
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• 2007

Dye-sensitized solar cell using conversion of solar energy to electrical energy appeared that which solves a environmental matter. The dye-sensitized solar cell uses nano-crystalline oxide semiconductor for absorbing dye. The $TiO_2$ is used most plentifully. The efficiency of the dye-sensitized solar cell changes consequently in the particle size, morphology, crystallization and surface state of the $TiO_2$. In this paper, we report The effect of titania$(TiO_2)$ thickness on the performance of dye-sensitized solar cells. Using doctor blade method, It produced the thickness of the $TiO_2$ with $7\;{\mu}m,\;10\;{\mu}m,\;13\;{\mu}m$. The efficiency was the best from $10{\mu}m$. It had relatively low efficiency on the thickness from $7\;{\mu}m\;to\;13\;{\mu}m$. The reason why it presents low efficiency on $7\;{\mu}m$ thickness is that excited electrons can not be delivered enough due to thin thickness of $7\;{\mu}m\;TiO_2$. And The reason why it presents low efficiency on $13\;{\mu}m$ thickness is that thick $13\;{\mu}m\;TiO_2$ can not penetrate the sunlight enough.

• Journal of Preventive Medicine and Public Health
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• 제51권6호
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• pp.265-274
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• 2018

Objectives: A positive association between air pollution and both the incidence and prevalence of diabetes mellitus (DM) has been reported in some epidemiologic and animal studies, but little research has evaluated the relationship between air pollution and diabetic coma. Diabetic coma is an acute complication of DM caused by diabetic ketoacidosis or hyperosmolar hyperglycemic state, which is characterized by extreme hyperglycemia accompanied by coma. We conducted a time-series study with a generalized additive model using a distributed-lag non-linear model to assess the association between ambient air pollution (particulate matter less than $10{\mu}m$ in aerodynamic diameter, nitrogen dioxide [$NO_2$], sulfur dioxide, carbon monoxide, and ozone) and emergency department (ED) visits for DM with coma in Seoul, Korea from 2005 to 2009. Methods: The ED data and medical records from the 3 years previous to each diabetic coma event were obtained from the Health Insurance Review and Assessment Service to examine the relationship with air pollutants. Results: Overall, the adjusted relative risks (RRs) for an interquartile range (IQR) increment of $NO_2$ was statistically significant at lag 1 (RR, 1.125; 95% confidence interval [CI], 1.039 to 1.219) in a single-lag model and both lag 0-1 (RR, 1.120; 95% CI, 1.028 to 1.219) and lag 0-3 (RR, 1.092; 95% CI, 1.005 to 1.186) in a cumulative-lag model. In a subgroup analysis, significant positive RRs were found for females for per-IQR increments of $NO_2$ at cumulative lag 0-3 (RR, 1.149; 95% CI, 1.022 to 1.291). Conclusions: The results of our study suggest that ambient air pollution, specifically $NO_2$, is associated with ED visits for diabetic coma.

• 영어영문학
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• 제57권2호
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• pp.315-337
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• 2011

This paper aims to examine a truth about love - the close relationship between a person's passionate love and that same person's loneliness and suppressed desires, a relationship that Carson McCullers (1917-1967) portrays in The Ballad of the Sad Cafe. McCullers, one of several brilliant writers from Southern America, managed to overcome her cruel situation and showed deep insight into the human condition, particularly in regard to the relation between love and isolation. The Ballad of the Sad Cafe, like her other works, examines the spiritual isolation and the agony of love that three lovers experience. The love in this story is a triangular relationship among the three main characters, Amelia, Lymon and Marvin Macy. The distinctive characteristics of love described in this story are that each character falls into blind and passionate love for the person he/she loves, no matter how the beloved responds. Love also changes the lover, not the beloved, revealing the completely opposite nature of the lover. The opposite nature and the inner secrets that the love reveals about the lovers reflect their frustrated and suppressed desires, which is femininity and motherhood for Amelia, non-violent masculine power for Macy, and physical attraction and power for the hunchback, Lymon. These suppressed desires are rooted in the deep sense of frustration that they had to experience in their childhood. In short, the seemingly unconditional love of the main characters is not an ideal, altruistic love, but a reflection of their inner desires. This story, however, does not seem to criticize this kind of love but simply tries to give an honest picture of what love might be. It also admits that 'deformed' love is still better than no love (and consequently no stimulus) because what really damages and causes decay in human beings and in a community, is the state of boredom.

• The Korean Journal of Ecology
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• 제27권4호
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• pp.225-230
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• 2004

The impact of slash and burning on microbial biomass C, N and P in soils of semi-evergreen tropical deciduous forest were studied from February 1999 to January 2000. The experimental sites were located near Moreh town in the Chandel district of Manipur state (India) along the Indo-Myanmar border between 23° 49' N-24°28'N latitude and 93°45'E-94°16'E longitude. Microbial biomass C ranged from 319.50 ㎍ g/sup -1/ 905.50㎍ g/sup -1/ in the slash and burnt site and from 209.50 ㎍ g/sup -1/ to 708.80 ㎍ g/sup -1/ soil in the forest site. Microbial N ranged from 19.30 ㎍ g/sup -1/ to 99.45 ㎍ g/sup -1/ in the slash and burnt site and from 16.08㎍ g/sup -1/ to 88.90 ㎍ g/sup -1/ in the forest site. Microbial P varied from 10.90 ㎍ g/sup -1/ to 32.21 ㎍ g/sup -1/ in the slash and burnt site and from 2.50 ㎍ g/sup -1/ to 17.60 ㎍ g/sup -1/ in the forest site in different months throughout the year. Microbial biomass C, N and P were recorded to be higher in the slash and burnt site compared to the forest site The conversion of forest into slash and burnt site for agriculture - the traditional shilling cultivation practiced by tribal people in the north- eastern India leads to addition of large amount of organic matter in the soil thereby exhibiting higher values of microbial biomass C, N and P in the recent slash and burnt site than that of the forest site. Relationship between the soil moisture, soil organic C and microbial biomass C, N and P were found to be correlated significantly in both the sites.

• 천문학회지
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• 제48권1호
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• pp.83-92
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• 2015

Recent large scale surveys such as Sloan Digital Sky Survey have produced homogeneous samples of multiple-image gravitationally lensed quasars with well-defined selection effects. Statistical analysis on these can yield independent constraints on cosmological parameters. Here we use the image separation statistics of lensed quasars from Sloan Digital Sky Survey Quasar Lens Search (SQLS) to derive constraints on cosmological parameters. Our analysis does not require knowledge of the magnification bias, which can only be estimated from the detailed knowledge on the quasar luminosity function at all redshifts, and includes the consideration for the bias against small image separation quasars due to selection against faint lens galaxy in the follow-up observations for confirmation. We first use the mean image separation of the lensed quasars as a function of redshift to find that cosmological models with extreme curvature are inconsistent with observed lensed quasars. We then apply the maximum likelihood test to the statistical sample of 16 lensed quasars that have both measured redshift and magnitude of lens galaxy. The likelihood incorporates the probability that the observed image separation is realized given the luminosity of the lens galaxy in the same manner as Im et al. (1997). We find that the 95% confidence range for the cosmological constant (i.e., the vacuum energy density) is $0.72{\leq}{\Omega}_{\Lambda}{\leq}1.0$ for a flat universe. We also find that the equation of state parameter can be consistent with -1 as long as the matter density ${\Omega}_m{\leq}0.4$ (95% confidence range). We conclude that the image separation statistics incorporating the brightness of lens galaxies can provide robust constraints on the cosmological parameters.

• 기술혁신학회지
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• 제9권3호
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• pp.514-537
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• 2006

최근 과학기술이 국가발전에서 차지하는 비중이 더욱 커짐에 따라 각 국가들은 그에 대한 정책과 관련제도를 한층 강화하고 있다. 남북한 역시 1990년대 후반부터 과학기술을 국가의 중요정책으로 취급하고 이를 효율적으로 추진하기 위하여 과학기술 행정체계의 개편과 관련법령에 대한 정비를 지속적으로 시행하고 있다. 이 논문은 남북 과학기술정책의 제도적 기반이 되는 과학기술 기본법제의 우영 상황을 살펴봄으로써, 남북 과학기술 협력 활성화 및 향후의 관련법제의 통일화에 대비한 양 법제간의 정합 가능성을 탐색해 보는 것을 목적으로 하고 있다. 이를 위해 남북 헌법상의 과학기술 관련규정과 과학기술에 관한 총괄규범으로서 기능하는 남한의 과학기술기본법과 북한의 과학기술법에 대하여 그 규정체계와 내용을 개관하고 상호간의 유사점과 차이점을 비교분석하였다.

• 한국언론정보학보
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• 제51권
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• pp.136-155
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• 2010

미디어 다양성은 글로벌 시장에서의 경쟁이라는 '환상의 짝꿍'과 더불어 한국 미디어 정책을 규정하는 화두로 등장했다. 미국식 기능 행태주의가 주도하는 미디어 정책은 다양성을 시장경쟁, 소비주체의 자유로운 선택이라는 좁은 울타리에 가둔다. 이에 본 논문은 다양성 그 자체를 하나의 완결한 정책목표로 보는 시각에 근본적인 문제제기를 하고자 한다. 다양성이 미디어 정책 담론의 전면에 등장하는 계기를 한국의 중첩적 정치 경제 맥락 속에서 파악하면서, 본 논문은 기존 계량주의 다양성 연구를 비판적으로 분석한다. 나아가 미디어 다양성이 '측정의 과학'에 과도하게 집착해 탈정치화하는 경향을 주목하며 문화연구자들이 미디어 다양성을 보다 진보적으로 전취하기 위한 몇 가지 제안을 하고자 한다. 핵심적인 주장은 미디어 다양성은 시장의 경쟁과 미디어 상품의 다양화라는 신자유주의의 경제논리를 넘어서야 한다는 것이다. 비판적 문화연구자들은 미디어 다양성을 한국 민주주의의 심화라는 보다 큰 정치 프로젝트 속에서 미디어 공공성의 강화, 독립 대안 미디어에 대한 실질적 지원, 급진적 정체성의 정치학 등의 전략과 함께 고려해야 한다.

• Journal of Radiation Protection and Research
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• 제36권1호
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• pp.35-43
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• 2011

The PHENIX Experiment is the largest of the four experiments that have taken data at the Relativistic Heavy Ion Collider. PHENIX, the Pioneering High Energy Nuclear Interaction eXperiment, is designed specifically to measure direct probes of the collisions such as electrons, muons, and photons. The primary goal of PHENIX is to discover and study a new state of matter called the Quark-Gluon Plasma. Among many particles, muons coming from W-boson decay gives us key information to analyze the spin of proton. Resistive plate chambers are proposed as a suitable solution as a muon trigger because of their fast response and good time resolution, flexibility in signal readout, robustness and the relatively low cost of production. The RPC detectors for upgrade were assembled and their performances were evaluated. The procedure to make the detectors better was optimized and described in detail in this thesis. The code based on ROOT was written and by using this the performance of the detectors made was evaluated, and all of the modules for north muon arm met the criteria and installation at PHENIX completed in November 2009. As RPC detectors that we made showed fast response, capacity of covering wide area with a resonable price and good spatial resolution, this will give the opportunity for applications, such as diagnosis and customs inspection system.

• Reproductive and Developmental Biology
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• 제30권4호
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• pp.279-285
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• 2006

Vitrification has been suggested to be an effective method for the cryopreservation of human ES cells. However, the efficiency of vitrification with different vehicles remains a matter of ongoing controversy. The objective of this study was to assess the efficiency of cryopreservation in human ES cells by vitrification using different vehicles. A human ES cell line and a variety of vehicles, including micro-droplet (MD), open-pulled straw (OPS) and electron microscopic grid (EM-grid), were employed in an attempt to assess vitrification efficiency. In order to evaluate the survivability and the undifferentiated state of the post-vitrified human ES cells, we conducted alkaline phosphatase staining and characterization via both RT-PCR and immunofluorescence assays. The survival rates of the post-vitrified human ES cells using MD, OPS and EM-grid were determined to be 61.5%, 66.6% and 53.8%, respectively. There also exist significant differences between slow-freezing and vitrification (p<0.01). However, no significant differences were detected between the vehicle types. Finally, the pluripotency of human ES cells after thawing was verified by teratoma formation. Cryopreservation using vitrification is more effective than slow-freezing, and the efficiency of vehicles proved effective with regard to the preservation of human ES cells.

• 한국물환경학회지
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• 제22권1호
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• pp.23-29
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• 2006

Biosorption technology was used to remove hazardous materials from wastewater, herbicide, heavy metals, and radioactive compounds, based on binding capacities of various biological materials. Biosorption process can be explained by two steps; the first step is that target contaminants is in contact with microorganisms and the second is that the adsorbed target contaminants is infiltrated with inner cell through metabolically mediated or physico-chemical pathways of uptake. Until recently, no information is available to explain the definitive mechanism of biosorption. The purpose of this study is to evaluate biosorption capabilities of organic matters using activated sludge and to investigate affecting factors upon biosorption. Over 49% of organic matter could be removed by positive biosorption reaction under anoxic condition within 10 minutes. The biosorption capacities were constant at around 50 mg-COD/mg-MLSS for all batch experiments. As starvation time increased under aerobic or anaerobic conditions, biosorption capacity increased since higher stressed microorganisms by starvation was more brisk. Starvation stress of microorganisms was higher at aerobic condition than anaerobic one. As temperature increased or easily biodegradable carbon sources were used, biosorption capacities increased. Consequently, biosorption can be estimated by biological -adsorbed capability of the bacterial cell-wall and we can achieve the cost-effective and non -residual denitrification with applying biosorption to the bio-reduction of nitrate.