텔레비젼(TV)생산업체 근로자들의 영상단말기(VDT)작업이 시력과 안증상에 미치는 영향

우극현,최광서,정영연,한구웅,박정한,이종협,Woo, Kuck-Hyeun,Choi, Gwang-Seo,Jung, Young-Yeon,Han, Gu-Wung,Park, Jung-Han,Lee, Jong-Hyeob 대한예방의학회 1992 예방의학회지 Vol.25 No.3

영상단말기 (VDT)작업이 시력과 안증상에 미치는 영향을 알아보기 위해 1991년 7월에서 10월 사이에 구미시의 1개 TV생산업체에 종사하는 근로자들 가운데 채용 당시 안과적으로 문제가 없었고, 나안시력이 1.0 이상인 40세 미만 남자 338명을 대상으로 일일 평균 화면작업시간이 4시간 미만인 근로자(I군, 60명)와 4시간 이상인 근로자(II군, 204명)를 폭로군으로 하고 유사한 작업환경에서 근무하는 비화면작업자(74명)를 비폭로군으로 나누어 연령, 작업경력, 교대근무형태, 확대경 사용유무, 1일 평균 TV시청 시간 및 수면시간과 그리고 안자각증상에 대한 설문조사를 실시한 후, 안과적검사를 시행하였다. 조사시 원거리시력 (양안의 평균시력)이 채용시에 비해 0.15 이상 저하된 비율은 II군이 20.6%로 비화면작업군의 14.9 %, I군의 15.0 % 보다 다소 높았으나 통계적으로 유의한 차는 아니었다. 연령, 작업경력, 확대경 사용유무, 교대근무형태 등에 따라 층화하여 원거리시력 저하율을 비교해 본 결과 세 군간에 통계적으로 유의한 차가 없었다. 근거리시력 저하율도 비화면작업군이 28.4 %, I군이 18.3 %, II군이 27.5 %로 통계적으로 유의한 차이가 없었으며, 연령 등 4가지 독립변수를 층화하여 비교해 보아도 유의한 차이가 없었다. 안자각증상 호소율은 안피로를 포함한 7가지 항목에서 눈물이 나는 것을 제외한 모든 항목에서 비화면작업군에 비해 I군이, I군 보다는 II군이 통계적으로 유의하게 높았다(P<0.01). 화면작업자 264명 가운데 조명이 나쁜 장소에서 일하는 근로자들의 원거리시력 저하율과 안자각증상 호소율이 조명이 좋은 작업장에서 일하는 근로자보다 더 높았다(P<0.05). 7가지 안자각증상을 각 증상 마다 늘 느끼는 경우는 2, 가끔 느끼면 1, 느끼지 않으면 0으로 점수화하여 개인별 총 안증상 점수를 구해 세 군간에 원거리시력 차이 유무별로 비교해 본 결과, 시력차 유무에 따른 평균 안자각증상 점수의 차는 없었으나 시력차 유무에 관계없이 II군의 평균 안자각증상 점수가 6.13 으로 I군(3.53) 또는 비화면작업군(3.30) 보다 훨씬 더 높았다(P<0.01). 안자각증상 점수와 유의한 상관관계를 보인 독립변수들은 화면작업시간, 확대경 사용유무, 교대근무형태 등이었고, 채용시와 조사시 원거리시력 차이, 원거리시력과 근거리시력 차이, 누액분비기능, 안압, 굴절력 등과 유의한 상관관계를 보인 독립 변수는 하나도 없었다. 안자각증상 점수를 종속변수로 하는 중선형 회귀분석 결과에서는 화면작업시간이 길수록, 단부제나 2교대 근무자보다 3교대 근무자에서 유의한 선형관계를 나타내었다(P<0.01). 본 조사에서는 1일 장시간 VDT작업으로 시력이 저하되는 것은 관찰할 수 없었고 안자각증상은 유발되는 것으로 나타났다. 안자각증상의 예방을 위해 VDT 작업장의 조명을 적절하게 유지하고 장시간 연속해서 작업하지 않도록 작업관리를 해야 할 것이다. This study was conducted to evaluate the effect of VDT work on eyes and vision among workers in a TV manufacturing plant. The study subjects consisted of 264 screen workers and 74 non-screen workers who were less than 40 years old male and had no history of opthalmic diseases such as corneal opacities, trauma, keratitis, etc and whose visual acuity on pre-employment health examination by Han's test chart was 1.0 or above. The screen workers were divided into two groups by actual time for screen work in a day : Group I, 60 workers, lesser than 4 hours a day and group II, 204 workers, more than 4 hours a day. From July to October 1992 a questionnaire was administered to all the study subjects for the general charateristics and subjective eye symptoms after which the opthalmologic tests such as visual acuity, spherical equivalent, lacrimal function, ocular pressure, slit lamp test, fundoscopy were conducted by one opthalmologist. The proportion of workers whose present visual acuity was decreased more than 0.15 in comparison with that on the pre-employment health examination by Han's test chart was 20.6% in Group II. 15.0% in Group I and 14.9% in non-screen workers. However, the differences in proportion were not statistically significant. The proportion of workers with decreased visual acuity was not associated with the age, working duration, use of magnifying glass and type of shift work (independent variables) in all of the three groups. However, screen workers working under poor illumination had a higher proportion of persons with decreased visual acuity than those working under adequate illumination (P<0.05) . The proportion of workers whose near vision was decreased was 27.5% in Group II, 18.3% in Group I, and 28.4% in non-screen workers and these differences in proportion were not statistically significant. Changes of near vision were not associated with 4 independent variables in all of the three groups. Six out of seven subjective eye symptoms except tearing were more common in Group I than in non-screen workers and more common in Group II than in Group I (P<0.01). Mean of the total scores for seven subjective symptoms of each worker(2 points for always, 1 point for sometimes, 0 point for never) was not significantly different between workers with decreased visual acuity and workers with no vision change. However, mean of the total scores for Group II was higher than those for the Group I and non-screen workers (P<0.01). Total eye symptom scores were significantly correlated with the grade of screen work, use of magnifying glass, and type of shift work. There was no independent variable which was correlated with the difference in visual acuity between the pre-employment health examination and the present state, the difference between far and near visions, lacrimal function, ocular pressure, and spherical equivalent. Multiple linear regression analysis for the subjective eye symptom scores revealed a positive linear relationship with actual time for screen work and shift work(P<0.01). In this study it was not observed that the VDT work decreased visual acuity but it induces subjective eye symptoms such as eye fatigue, blurred vision, ocular discomfort, etc. Maintenance of adequate illumination in the work place and control of excessive VDT work are recommended to prevent such eye symptoms.

碎石骨材 콘크리트의 力學的 特性에 關한 實驗的 硏究

최영화,김한철,한천구 대구대학교 산업기술연구소 1988 産業技術硏究 Vol.7 No.-

It is recently becoming one of the serious problems to provide the good quality aggregate for concrete because of natural aggregate shortage. The aim of this study is to analyze mechanical properties and their correlastionship of the various concrete composed of crushed sand and crushed stone which expected to be a good substitute for river sand and river gravel. The result showed that compressive strength, tensile strength and static moduls of elasticity of the different concrete composed of crushed sand and crushed stone were generally higher, though lower in slump, than those of the concrete composed of natural river aggregate, and the correlationship of each strength was pretty good.

Layer-by-Layer Doping of Few-Layer Graphene Film

Gü,neş,, Fethullah,Shin, Hyeon-Jin,Biswas, Chandan,Han, Gang Hee,Kim, Eun Sung,Chae, Seung Jin,Choi, Jae-Young,Lee, Young Hee American Chemical Society 2010 ACS NANO Vol.4 No.8

<P>We propose a new method of layer-by-layer (LbL) doping of thin graphene films. Large area monolayer graphene was synthesized on Cu foil by using the chemical vapor deposition method. Each layer was transferred on a polyethylene terephthalate substrate followed by a salt-solution casting, where the whole process was repeated several times to get LbL-doped thin layers. With this method, sheet resistance was significantly decreased up to ∼80% with little sacrifice in transmittance. Unlike samples fabricated by topmost layer doping, our sample shows better environmental stability due to the presence of dominant neutral Au atoms on the surface which was confirmed by angle-resolved X-ray photoelectron spectroscopy. The sheet resistance of the LbL-doped four-layer graphene (11 × 11 cm<SUP>2</SUP>) was 54 Ω/sq at 85% transmittance, which meets the technical target for industrial applications.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2010/ancac3.2010.4.issue-8/nn1008808/production/images/medium/nn-2010-008808_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn1008808'>ACS Electronic Supporting Info</A></P>

Nuclear DNA Quantification of some Ceramialean Algal Spermatia by Fluorescence Microscopic Image Processing and their Nuclear SSU rDNA Sequences

Han-Gu Choi,김형섭,오윤식,이인규,Eun-Young Lee 한국조류학회I 2004 ALGAE Vol.19 No.2

Nuclear DNA contents of spermatia from eight ceramiacean and four dasyacean algae (Ceramiales, Rhodophyta) and microspores from two land plants were estimated by fluorescence microscopic image processing and their nuclear SSU rDNA sequence data were analyzed. In frequency distribution patterns, the DAPI-stained nuclear volume (NV) of spermatia showed two peaks corresponding to 1C and 2C. Nuclear 2C DNA contents estimated from NV were 0.45-2.31 pg in ceramiacean and 0.40-0.57 pg in dasyacean algae and 8.42-9.51 pg in two land plants, Capsicum annuum and Nicotiana tabacum. By nuclear patterning of vegetative cells derived from an apical cell, 2C DNA contents of spermatia were 2.31 pg in an alga having uninucleate and non-polyploid nucleus (Aglaothamnion callophyllidicola), 0.45-1.94 pg in algae having uninucleate and polyploid nucleus (Antithamnion spp. and Pterothamnion yezoense), and 0.40-0.62 pg in algae having multinucleate and non-polyploid nuclei (Griffithsia japonica and dasyacean algae). Each mature spermatium and microspore (pollen grain) seemed to have a 2C nucleus, which may provide a genetic buffering system to protect the genetic content of a spermatium and microspore from potentially lethal mutations. Nuclear DNA content and SSU rDNA sequence of Antithamnion sparsum from Korea were reasonably different from those of Antithamnion densum from France. The data did not support the previous taxonomic studies that these two taxa could be conspecific.

Nuclear DNA Quantification of Some Ceramialean Algal Spermatia by Fluorescence Microscopic Image Processing and their Nuclear SSU rDNA Sequences

Choi, Han-Gu,Lee, Eun-Young,Oh, Yoon-Sik,Kim, Hyung-Seop,Lee, In-Kyu The Korean Society of Phycology 2004 ALGAE Vol.19 No.2

Nuclear DNA contents of spermatia from eight ceramiacean and four dasyacean algae (Ceramiales, Rhodophyta) and microspores from two land plants were estimated by fluorescence microscopic image processing and their nuclear SSU rDNA sequence data were analyzed. In frequency distribution patterns, the DAPI-stained nuclear volume (NV) of spermatia showed two peaks corresponding to 1C and 2C. Nuclear 2C DNA contents estimated from NV were 0.45-2.31 pg in ceramiacean and 0.40-0.57 pg in dasyacean algae and 8.42-9.51 pg in two land plants, Capsicum annuum and Nicotiana tabacum. By nuclear patterning of vegetative cells derived from an apical cell, 2C DNA contents of spermatia were 2.31 pg in an alga having uninucleate and non-polyploid nucleus (Aglaothamnion callophyllidicola), 0.45-1.94 pg in algae having uninucleate and polyploid nucleus (Antithamnion spp. and Pterothamnion yezoense), and 0.40-0.62 pg in algae having multinucleate and non-polyploid nuclei (Griffithsia japonica and dasyacean algae). Each mature spermatium and microspore (pollen grain) seemed to have a 2C nucleus, which may provide a genetic buffering system to protect the genetic content of a spermatium and microspore from potentially lethal mutations. Nuclear DNA content and SSU rDNA sequence of Antithamnion sparsum from Korea were reasonably different from those of Antithamnion densum from France. The data did not support the previous taxonomic studies that these two taxa could be conspecific.

PHYLOGENETIC RELATIONSHIPS AMONG LINEAGES OF THE CERAMIACEAE (CERAMIALES, RHODOPHYTA) BASED ON NUCLEAR SMALL SUBUNIT rDNA SEQUENCE DATA¹

Choi, Han-Gu,Kraft, Gerald T.,Kim, Hyung-Seop,Guiry, Michael D.,Saunders, Gary W. Blackwell Publishing Ltd 2008 Journal of phycology Vol.44 No.4

<P>Phylogenetic relationships among 69 species of the Ceramiales (51 Ceramiaceae, six Dasyaceae, seven Delesseriaceae, and five Rhodomelaceae) were determined based on nuclear SSU rDNA sequence data. We resolved five strongly supported but divergent lineages among the included Ceramiaceae: (i) the genus <I>Inkyuleea</I>, which weakly joins other orders of the Rhodymeniophycidae rather than the Ceramiales in our analyses; (ii) the tribe Spyridieae, which is sister to the remainder of the included ceramialean taxa; (iii) the subfamily Ceramioideae, weakly including the tribe Warrenieae; (iv) the subfamily Callithamnioideae; and (v) the subfamily Compsothamnioideae, which emerges as sister to the Dasyaceae/Delesseriaceae/Rhodomelaceae complex, thus rendering the Ceramiaceae sensu lato unequivocally paraphyletic, as has been argued separately on anatomical grounds by Kylin and Hommersand. Our data support a restricted concept of the Ceramiaceae that includes only one of the five lineages (Ceramioideae) that we have resolved. In addition to failing to ally with the Ceramiales in our molecular analyses, species of <I>Inkyuleea</I> differ substantially from other Ceramiaceae sensu lato in details of pre- and postfertilization development. The genus <I>Inkyuleea</I> is here assigned to the Inkyuleeaceae fam. nov., which we provisionally retain in the Ceramiales. Species of <I>Spyridia</I> also differ from the remaining Ceramiaceae in their postfertilization development, and, in light of our molecular data, the genus <I>Spyridia</I> is assigned to the Spyridiaceae. The Callithamnioideae is strongly monophyletic (100% in all analyses), which, in combination with key anatomical differences, supports elevation to family status for this lineage as the Callithamniaceae. Similarly, the Compsothamnioideae is solidly monophyletic in our molecular trees and has a unique suite of defining anatomical characters that supports family status for a complex that we consider to include the tribes Compsothamnieae, Dasyphileae, Griffithsieae, Monosporeae, Ptiloteae, Spermothamnieae, Sphondylothamnieae, Spongoclonieae, and Wrangelieae, for which the reinstated family name Wrangeliaceae is available.</P>

The Development of Endless Rotating Welding System using Hot-wire TIG process

Sang-Gu Choi(최상구),Kwang-Duk Choi(최광덕),Ryun-Han Kim(김륜한),Sang-Hun Ryu(유상훈) 대한용접·접합학회 2015 대한용접학회 특별강연 및 학술발표대회 개요집 Vol.2015 No.05

Oriental × Trumpet Interspecific Hybrid Lily Cultivar with Double Color,‘Crown Bell’

Chan Gu Lee,Jong Jin Choi,Won Chun Choi,Seung Ho Han,Taeg Yong Choi 한국화훼학회 2018 화훼연구 Vol.26 No.1

‘Crown Bell’ 품종은 생육이 왕성하고 엽소 및 잎마름병에 강하며 꽃이 큰 백합 신품종을 육성하기 위하여 2008년 충남농업 기술원 태안백합시험장에서 교배한 OT(Oriental hybrid × Trumpet hybrid)계통의 종간교잡종이다. 모본으로는 노란색의 OT계통 ‘Yelloween’ 품종을, 부본으로는 분홍색의 Oriental계통 ‘Carmina’품종을 화주절단수분법에 의해 교배한 후 2009년부터 2011년까지 기내 종자배양 및 증식 육묘하여 2012년 우수계통(OT12-8)을 1차 선발하였다. 2012년부터 2014년도에 걸쳐 ‘Nymph’ 품종을 대조구로 하여 보통재배를 통한 특성검정을 실시하였으며, 2013년 화훼연구소에서 개최한 신품종 평가회에서 기호성이 우수한 개체를 2차 선발하여 ‘Chungnam OT-2’로 명명한 후 농촌진흥청 농작물직무육성 신품종선정위원회 심의를 거쳐 국립종자원에 ‘Crown Bell’로 품종보호 출원하였다. ‘Crown Bell’ 품종의 중부지역 자연 개화는 6월 26일로 ‘Nymph’ 품종보다 약간 빨랐으며, 초장은 136.1cm이고, 반점없는 복색(크림색+적색)의 화색을 가진 상향개화성을 나타내었다. 재배에 있어서는 잎마름병과 진딧물 등의 병충해 방제를 주기적으로 실시하고, 양수분 관리 등 일반적인 재배관리를 통해 고품질 절화 백합 및 구근 생산이 가능하다. A new Oriental × Trumpet (OT) intersectional hybrid lily cultivar ‘Crown Bell’ with flourishing growth and high resistance to leaf burn and Botrytis was developed at the Taean Lily Experiment Station of Chungcheongnam-do Agricultural Research and Extension Services in 2014. In 2008, the yellow-flowered female parent Lilium OT hybrid ‘Yelloween’ was crossed with the pink-flowered male parent L. Oriental hybrid ‘Carmina’ using a cut style pollination method (CSM). Adaptation trials were conducted on the candidate line to develop various characteristics through seed culture in vitro, multiplication, and seedling from 2009 to 2011. The first selection was made in 2012, and the line was tentatively named ‘OT12-8’. This study was compared the external shape type, bulb production, growth, and flowering characteristics with those of ‘Nymph’ from 2012 to 2014. Consumer preference for the evaluated characteristics was surveyed during a lily flower show held at the Flower Research Institute in 2013, and a second selection, named ‘Chungnam OT-2’, was made according to results from the show. This line was registered as the OT intersectional hybrid lily cultivar ‘Crown Bell’ in 2014. The natural flowering time of ‘Crown Bell’ began on 26 June, which is later than ‘Nymph’ in the central district. The f lower stalk of ‘Crown Bell’ was 136.1 cm long and flowers with double color (cream-red) petals without spots bloomed upward. Production of high quality cut flowers and bulbs required c aref ul u se o f general c ultivation t echniques including control of diseases and insects, and nutrient and moisture management.

오렌지색의 절화용 OT 종간잡종 백합 ‘오렌지벨’ 육성

이찬구(Chan Gu Lee),한승호(Sueng Ho Han),최원춘(Won Chun Choi),최종진(Jong Jin Choi),최택용(Taeg Yong Choi) 한국원예학회 2018 한국원예학회 학술발표요지 Vol.2018 No.5

노랑색의 절화용 OT 종간잡종 백합 ‘골든벨’ 육성

이찬구(Chan Gu Lee),한승호(Sueng Ho Han),최원춘(Won Chun Choi),최종진(Jong Jin Choi),최택용(Taeg Yong Choi) 한국원예학회 2017 한국원예학회 학술발표요지 Vol.2017 No.5