• 대한디지털의료영상학회논문지
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• 제11권1호
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• pp.5-13
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• 2009

There are several reasons to take X-ray in case of inpatients. Some of them who cannot ambulate or have any risk if move are taken portable X-ray at their wards. Usually, in this case, many other people-patients unneeded X-ray test, family, hospital workers etc-are indirectly exposed to X-ray by scatter ray. For that reason I try to be aware of free space scatter dose accurately and make the point at issue of portable X-ray better in this study. kVp dose meter is used for efficiency management of portable X-ray equipment. Mobile X-ray equipment, ionization chamber, electrometer, solid water phantom are used for measuring of free space scatter dose. First of all the same surroundings condition is made as taken real portable X-ray, inquired amount of X-ray both chest AP and abdomen AP most frequently examined and measured scatter ray distribution of two tests individually changing distance. In the result of measuring horizontal distribution with condition of chest AP it is found that the mAs is decreased as law of distance reverse square but no showed mAs change according to direction. Vertical distribution showed the mAs slightly higher than horizontal distribution but it isnt found out statistical characteristic. In abdomen AP, compare with chest AP, free space scatter dose is as higher as five-hundred times and horizontal, vertical distribution are quite similar to chest AP in result. In portable X-ray test, in order to reduce the secondary exposure by free space scatter dose first, cut down unnecessary portable order the second, set up the specific area at individual ward for the test the third, when moving to a ward for the X-ray test prepare a portable shielding screen. The last, expose about 2m apart from patients if unable to do above three ways.

• 한국콘텐츠학회논문지
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• 제13권11호
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• pp.636-643
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• 2013

방송시장의 급격한 환경변화는 지역방송의 사회적 입지를 위축시키고 재정적 기반을 위협하고 있지만, 동시에 인터넷과 모바일 기반의 플랫폼과 스마트 미디어는 새로운 콘텐츠 유통의 활로로서 가능성을 부여하고 있다. 본 연구는 지역 지상파방송의 수퍼스테이션 사례 및 전문가 인터뷰를 통해 변화하는 방송환경에 적합한 지역방송의 유통모델을 살펴보고, 새로운 유통모델 확립을 위해 지역방송의 역할과 추진해야 할 전략을 논의하였다. MBCNET의 재무성과 및 시청률, 뉴미디어 유통에 대한 분석결과, MBCNET은 콘텐츠 라이브러리와 MBC 지역방송사의 영향력에 힘입어 성공적인 성과를 내고 있는 것으로 나타났다. 그러나 지속적인 경쟁력 강화를 위해 콘텐츠와 플랫폼의 마케팅역량의 향상이 필요하며, 시청자들의 이용행태에 기반한 경쟁력 있는 콘텐츠의 제작역량 강화 및 N스크린 환경에 대응할 수 있는 조직의 정비가 필요한 것으로 분석되었다.

• 생물환경조절학회지
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• 제12권1호
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• pp.45-53
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• 2003

본 연구의 목적은 차광스크린 및 인공광을 이용하여 온실에 적절한 일일적산 광합성유효광량자속을 공급하는 기술을 개발하는 것이다. 차광율이 55%와 85%인 두 가지 종류의 차광스크린을 이용하여 목표광량을 얻는데 필요한 차광시간대를 분석한 결과, 조절하고자 하는 목표광량의 크기에 따라 적절한 차광율을 가진 차광재를 선택할 필요가 있는 것으로 판단되었다. 기상조건에 따라 광량변화가 많은 7월과 8월에 대하여 55%의 차광재를 이용하여 광조절 실험을 실시한 결과 무차광시의 실측값과 계산값의 차이가 최대 5 mol$.$ $m^{-2}$ $.$$d^{-1}$ 정도로 나타났다. 이러한 차이는 기상조건에 따라 일일적산 광량이 큰 차이가 있음을 감안하면 대체로 만족할 만한 결과로 판단된다. 광분포 시뮬레이션을 이용하여 적절한 광배치를 찾을 수 있었기 때문에 실제 인공광을 배치하는데 소요되는 시간을 많이 단축할 수 있었지만, 정확하게 목표한 광강도를 고르게 분포하도록 할 수 있는 광배치를 찾기가 쉽지 않았으며, 이에 대한 보다 더 많은 분석이 요구되었다. 목표한 일일적산 광합성유효광량자속을 얻는데 필요한 보광강도별 보광시간을 기상조건 및 월별로 계산하여 분석한 결과 보광강도는 필요보광량의 크기에 따라 적절한 값을 선택하여야 할 것으로 판단되었다. 55%차광재 및 300$\mu$mol$.$ $m^{-2}$ $.$ $s^{-1}$의 보광강도를 이용하여 5월말에서 6월초까지 광량 제어실험을 실시한 결과 최대 3mol$.$ $m^{-2}$ $.$$d^{-l}$ 정도의 오차를 보여주었다. 이러한 차이는 동일한 달에 같은 기상조건에서도 일일적산 광량의 차이가 있고 하루 중 기상상태도 많은 변화가 있기 때문인 것으로 판단된다. 그러나 기상조건에 따른 일별 최대차이가 30 mol$.$ $m^{-2}$ $.$$d^{-l}$ 정도임을 감안하면 조절효과는 만족할 만한 결과로 판단된다. 본 연구의 결과는 비록 상추재배를 위한 광량조절기술이지만 다른 작물에 대해서도 본 연구에서 제시한 자료 및 조절방법을 동일하게 적용할 수 있을 것으로 기대된다.

• Ocean and Polar Research
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• 제26권2호
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• pp.367-376
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• 2004

Macrobenthos were collected at 7 stations located from $5^{\circ}N$ to $10^{\circ}N$ with 1o interval along the longitude of $131^{\circ}W$ using a box corer with sampling area of $0.25\;m^2$ in July, 1999. In order to see the vertical distribution of macrobenthos in sediments, each subcore sample was divided into 5 layers with 1 cm interval up to 6 cm depth. Each subcore sample was sieved through 0.3 mm mesh screen and fixed with 10% Rose Bengal added formalin. A total of 22 faunal groups in 11 phyla were sampled and the average density was $959\;{\pm}\;584\;ind./m^2$. Foraminiferans comprised 34.8% of total specimens were the most abundant fauna, and followed by nematodes (27.5%), polychaete worms (15.7%), and benthic harpactoid copepods (10.4%). A latitudinal trend was shown in the distribution of macrobenthos; the maximum density of $1,832\;ind./m^2$ appeared at station N06 and the most poverished community occurred at station N09 with the density of $248\;ind./m^2$. The density of typical macrofaunal taxa except foraminiferans and nematods was $116\;ind./m^2$. In the vertical distribution of macrobenthos, more than 70% of macrobenthos occurred in the upper 2 cm layer, and upper 4 cm layer contained about 90% of macrofauna. Polychaete worms consisted of 22 families, and cirratulid and paraonid worms were dominant polychaete species. The prominant feeding guilds of polychaete worms were SDT (surface, descretely motile, tenaculate feeding) and SMX (surface, motile, non-jawed); they comprised more than 50% of polychaete abundance. These feeding guilds of polychaete worms suggests that the deep sea benthos should be well adapted the newly settled deposits from water column, but this should be clarified by the further studies.

• 대한의생명과학회지
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• 제19권4호
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• pp.315-329
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• 2013

This study was conducted to evaluate the distribution, frequency, sensitization rate, and types of specific allergen in allergic patients. We analyzed allergens of 12,882 allergic patient's serum referred for Medical Laboratory using MAST Allergy Screen Test (Inhalation/food panel) from April, 2010 to March, 2011. Allergen reactivity were not detected in 833/12,882 (6.5%) allergic patients and the other allergic patients had two or more types of allergens of food and inhalant, respectively. In the distribution of the allergen food 73.4% (9,450/12,882 patients) was much higher than the pollen 26.6% (3,432/12,882 patients). The sensitization rate to each allergen showed garlic 26.7%, egg white 21.5% of food allergens, mugwort 24.9%, ragweed short 19.6% of pollen allergens, Candida albicans 10.5%, Alternaria spp. 7.9% of fungus allergens, and showed high sensitized rate to Dermatophagoides farinae 90.2%, Dermatophagoides pteronyssinus 77.8%, house dust 57% of indoor allergens, respectively. The specific allergens of food allergen, fungus allergen, and indoor allergen were more frequent in young child than adult, but pollen allergens were frequent in adult than young child. In seasonal distribution, the food allergen were frequent in summer and autumn, the pollen allergen in autumn, fungus allergen in spring and in winter, and indoor allergen in autumn and in winter. In conclusion, the mite of Dermatophagoides farinae and Dermatophagoides pteronyssinus, and house dust showed the highest sensitization rate in specific allergen of allergic patients. The allergens showed difference feature according to the age, region, and types of allergen.

• Radiation Oncology Journal
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• 제10권1호
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• pp.107-113
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• 1992

4-5MeV의 전자선은 피부표면의 흡수선량을 증가시키고 표면하 10mm 내외에서 급속히 감소함으로 Mycosis fungoides, Kaposi's sarcoma등 전신피부암에 대한 가장적당한 치료방사선으로 알려져왔다. 그러나 평면이 아니고 굴곡이 심한 인체표면에 균일한 선량을 계획하기는 많은 어려움이 있었다. 연세암센터에서는 1980년부터 시행하여왔던 6MeV 전자선의 마름모형, 네방향 조사방법을 개량하고 많은 문헌을 참고하여 상하 양방향의 조사면과 환자위치를 각각 여섯가지 자세로 나누어 조사(Six-Dual-Field)하는 방법을 사용하였으며 이에따른 전신피부표면의 선량과 선량분포를 측정하였다. 선형가속기에서 발생되는 6MeV 전자선을 0.5 cm 두께의 아크릴판으로 감약시키고 콜리메터가 완전히 열린 조사면을 상하 $19^{\circ}$씩 옮기므로서 타겟트에서 3m 거리에 약 $2m{\times}1m$의 균일한선량의 조사면(평탄도 $+3\%$)과 10 mm 내외의 실효깊이 ($80\%$, 선량지점) 및 산란선에 의한 피부표면선량을 증가시킬 수 있었다. 환자는 일부피부가 가려지지 않도록 팔과 다리를 적당한 자세로 고정시키고 전자선을 여섯방향에서 각각 2회씩 상하로 조사시키므로서 피부표면에 균일한 선량분포(표준편차 $5\%$)가 가능하였으며 $80\%$,의 심부율이 $8\~10mm$에서 측정되었다. 모든 측정은 인체등가팬텀과 폴리스틸렌팬텀을 사용하였으며 필름, 평형전리측정기 및 표준전리측정기를 이용하였다. 특히 환자피부표면의 흡수선량분포를 확인하기 위하여 열형광측정기와 반도체측정기를 이용하였으며 $6\~20$개의 소형 측정기를 환자 피부표면에 부착시킨후 전자선 치료과정 동안 피폭 시켜 측정하였고 그결과 차폐된 부위를 제외하고 평균 $10\%$, 이 내의 균일한 선량분포를 얻을수 있었다.

• 천문학논총
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• 제27권4호
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• pp.325-329
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• 2012

We will report our recent study on the properties of more than 1,600 galaxies detected by the AKARI All-Sky Survey with physical quantities based on optical and 21-cm observations, to understand the physics determining the infrared spectral energy distribution (Totani et al., 2011). We discover a tight linear correlation for normal star-forming galaxies between the radiation field strength of dust heating (corresponding to dust temperature) and the galactic-scale infrared radiation field, $L_{TIR}/R^2$. This is the tightest correlation of dust temperature ever known, and the dispersion along the mean relation is 13% in dust temperature. This relation can be explained physically by a thin layer of heating sources embedded in a thicker, optically-thick dust screen. We also find that the number of galaxies sharply drops when galaxies become optically thin against dust-heating radiation, indicating that a feedback process to galaxy formation (e.g., by the photoelectric heating) is working when dust-heating radiation is not self-shielded on a galactic scale. We discuss implications from these findings for the $M_{H_I}$ -size relation, the Kennicutt-Schmidt relation, and galaxy formation in the cosmological context.

• 산경연구논집
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• 제11권1호
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• pp.19-28
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• 2020

Purpose: This research aims to empirically investigate the motivation of corporate voluntary disclosure by exploring the impact of historical loss on corporate social responsibility disclosure (CSRD). Research design, data, and methodology: This paper takes Chinese A-share listed firms that issued standalone social responsibility reports during the period of 2009-2017 as a sample. Drawing on extant literature, this paper defines historical loss firms as firms with net profit greater than or equal to 0 and undistributed profit less than 0. The tendency score matching method (PSM) is used to find matching samples for historical loss firms. Then OLS regression is conducted to investigate the relationship between historical loss and corporate social disclosure. Results: The results show that historical loss has a significant positive impact on the quality of corporate social responsibility disclosure. After changing the measurement of independent and dependent variables as well as adopting different matching methods to screen the control group, the results still hold. Further research indicates that the relationship between historical loss and CSRD is influenced by corporate financing constraints and industry competition. Conclusions: This research supports the resource motivation hypothesis of corporate social responsibility disclosure, and provides empirical evidence for regulators to strengthen supervision on corporate disclosure.

• 대한조선학회논문집
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• 제53권4호
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• pp.300-306
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• 2016

The gas ventilated by supercavitation splits into smaller bubbles and follows the water passage of the cavitation tunnel. The bubbles quickly return to the test section by rather high speed flow, and interrupt the observation of the supercavitation. To secure clear observation in the test section, the bubble collecting section(settling chamber) of large volume is prepared to collect bubbles in the water passage ahead of the test section. The bubble collecting section should provide enough buoyancy effect to the bubbles for proper bubble collecting. However, rather high-speed oncoming flow produces non-uniform velocity distribution and deteriorates buoyancy effect in the bubble collecting section. In the present study, the bubble collecting space and three porous plates are designed and analyzed through numerical methods, and the bubble collecting function is experimentally validated by 1/10-scaled model in terms of the formation of uniformly low velocity distribution in the bubble collecting section.

• 한국표면공학회지
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• 제46권4호
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• pp.162-167
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• 2013

Encapsulation is required since organic materials used in OLED devices are fragile to water vapor and oxygen. Laser sealing method is currently used where IR laser is scanned along the glass-frit coated lines. Laser method is, however, not suitable to encapsulating large-sized glass substrate due to the nature of sequential scanning. In this work we propose a new method of encapsulation using Joule heating. Conductive layer is patterned along the sealing lines on which the glass frit is screen printed and sintered. Electric field is then applied to the conductive layer resulting in bonding both the panel glass and the encapsulation glass by melting glass-frit. In order to obtain uniform bonding the temperature of a conductive layer having a shape of closed loop should be uniform. In this work we conducted simulation for heat distribution according to the structure of a conductive layer used as a Joule-heat source. Uniform temperature was obtained with an error of 5% by optimizing the structure of a conductive layer. Based on the results of thermal simulations we concluded that Joule-heating induced encapsulation would be a good candidate for encapsulation method especially for large area glass substrate.