• Journal of Environmental Health Sciences
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• v.8 no.1
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• pp.67-80
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• 1982

In order to evaluate the psychosomatic health status of metal manufacturing industries workers and their working environments, the present study was conducted from March 1, 1981 to the end of September 1981. The data was obtained from the samples of metal manufacturing industries in Kyung-In Area and their 1, 162 employees. In addition, the 803 urban residents including students, office clerks, and general publics were sampled as control groups to compare with factory employees in psychosomatic analysis. The basic tool employed in the present study was the Todai Health Index (THI) which modified CMI and was developed by Tokyo University Research Team of Japan. The results of the present study were summarized as follows: 1. Working environments of the factories 1) The data shows that fabrication shop produced the highest noise level ranging from 91 to 96 dB (A) and iron and steel shop had the lowest noise level ranging from 81 to 86 dB (A). 2) Dust concentration was the highest in iron foundry shop ($3.8 mg/m^3$) and the lowest in fabrication shop ($1.2 mg/m^3$). 3) WBGT above threshold limit values (T.L.V.) was noted in steel shop (38$\circ$C) and iron foundry shop (34$\circ$C) 4) The concentration of Sulfur dioxide ($SO_2$)was 30.5ppm at steel shop and 12.0ppm at iron foundry shop. 5) The concentration of carbon monoxide (CO) was 140.0ppm at steel shop and 110.5ppm at iron foundry shop. 6) The atmospheric lead concentration was $0.49 mg/m^3$ at soldering shop. 2. The responses of psychosomatic complaints were much higher in steel shops group than in other manu-facturing group, except the response of aggressiveness. 3. The responses of psychosomatic complaints were much higher in industrial workers than in urban residents, except the responses of depression and aggressiveness (p < 0.01 ). 4. The psychosomatic symptoms which industrial workers and urban residents complained frequently were nervousness. agressiveness and lie scale in order. 5. The responses of psychosomatic complaints by sex were much higher in female group than in male group, except the response of aggressiveness. 6. The responses of psychosomatic complaints by age were that both the female and male group showed an increasing tendency in the all items, except the response of depression as age was increasing. 7. The responses of psychosomatic complaints by the length of services were that both the female and male group showed a tendency of increasing in physical symptoms as work years increased. 8. The responses of psychosomatic complaints were higher in unmarried group in the score of nervousness, aggressiveness, mental irritability and irregular life.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.472-479
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• 2012

The formation of volatile fatty acids(VFAs) and changes in pH, oxidation and reduction potential(Eh) and acid volatile sulfide(AVS) with the addition of yellow clay were investigated using microcosm systems to examine the effects of yellow clay dispersion on the anaerobic decomposition of Cochlodinium polykrikoides in marine sediments. The acetate concentration reached a maximum by day 4 and was 1.2-1.8 fold less in the sample treated with yellow clay compared to the untreated sample (224-270 vs. 333 uM). The formate concentration reached a maximum by day 1 and was 1.3-2.8 fold less in the sample treated with yellow clay compared to the untreated sample (202-439 vs. 563 uM). The propionate concentration reached a maximum by day 2 and was 1.5-1.8 fold less in the sample treated with yellow clay compared to the untreated sample (32.6 vs. 57.2 uM). After the amounts of acetate, formate and propionate peaked the levels dropped dramatically due to the utilization by sulfate reducing bacteria. The Eh of the samples treated with yellow clay was similar to the untreated sample on day 0 but was higher in the sample treated with yellow clay(140-206 mV) from days 4 to 17. AVS started to form on day 3 and this was sustained until day 6, and 1.2-2.2 fold less was produced in the sample treated with yellow clay compared to the untreated sample (40.2-69.3 vs. 83.2-93.8 mg/L). Accordingly, during the anaerobic decomposition of C. polykrikoides in marine sediments, yellow clay dispersal seems to suppress the reduction state of Eh and the formation of volatile fatty acids(acetate, formate and propionate) used as an energy source by sulfate reducing bacteria, indicating that this process controls the production of hydrogen sulfide that negatively affects marine organisms and the marine sediment environment.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.2
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• pp.132-140
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• 1991

The aim of this study was saving of chromium and nickel content in the austenitic stainless steels, SUS 316 and SUS 321. By control of primary solidification mode, new austenitic stainless steels with good weldability, high toughness and corrosion resistance could be developed. The main results obtained were as follows; 1. Hot crack resistance of laboratory melts was good and higher than imported austenitic stainless steel. 2. Cryogenic and room temperature toughness of laboratory melts were high and laboratory melts M-7 to M-9 showed very high toughness than SUS321 imported stainless steel. 3. Intergranular corrosion resistance of laboratory melts was higher than imported stainless steels, SUS316 and SUS321. 4. By this concept of controlling primary solidification mode, could save expensive alloy additives, chromium and nickel.

• Journal of the Korean Ceramic Society
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• v.40 no.10
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• pp.967-972
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• 2003

The inner-diameter 5 cm cold hollow cathode ion source was designed for the high current density and the homogeneous beam profile of ion beam. The ion source consisted of a cylindrical cathode, a generation part of magnetic field, a plasma chamber, convex type ion optic system with two grid electrode, and DC power supply system. The cold hollow cathode ion sources were classified into standard type (I), electron output electrode modified type (II). The operation of the ion source was done with discharge current, ion beam potential and argon gas flow rate. The modification of electron output electrode resulted in uniform plasma generation and uniform area of ion beam was extended from 5 cm to 20 cm. Improved ion source was evaluated with beam uniformity, ion current, team extraction efficiency, and ionization efficiency.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.355-360
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• 1997

In order to investigate the influence of photosensitized oxidation in the sun-dried irish moss (Chondrus Ocellatus), laver (Porphyra Yezoensis) and ultra violet irradiated oyster (Crassostrea gigas) the oxidation of lipid and isomers of hydroperoxides were analyzed by gas chromatography-mass spectrometry. The lipid contents of oyster, irish moss and layer were $2.7\%,\;0.1\%,\;0.1\%$ of respectively. Peroxide value, 56,7 meq/kg in the raw oyster was increased of 100.9 meq/kg by the U.V, irradiation for 4 hours. Also the peroxide values of the irish moss and laver were increased by the sun-drying. In the identification of hydroperoxides isomers by trimethylsily (TMS) derivative of photo-oxidized lipid from oyster, irish moss and laver, the proportions of positional isomer, 9-OOH and 13-OOH were dominant than those 10-OOH and 12-OOH.

• Journal of Chest Surgery
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• v.29 no.12
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• pp.1299-1305
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• 1996

The rat thoracic aorta was harvested to determine whether either hyperkalemla or hypothermia impairs the endothelium-dependent re axation of the vascular smooth muscle. Isolated thoracic aorta segments were studied in five groups(n=10 in each group). In group I(control), the isolated aortic seglnents were suspended in organ bath without any intervention. In group ll(endotheilum removAl). the endothelium of the aortic segment was removed by gentle rubbing of the intimal surface with a pair of forceps. In group III(457), IV(4mST), and V(3757), the aortic segments were exposed for 45minutes to 4$^{\circ}C$ St. Thomas hospital cardioplegic solution(57 : NaCl, 144.3; KCI, 19.6, MgCl:, 15.7 : CaCl, 2.2 mmol/L).4$^{\circ}C$ modified St. Thomas hospital cardioplegic solution(NaCl, 144.3 : KCI. 140.0 : MgCl:, 15.7; CaCl:. 2.2 mmol/L). and 37$^{\circ}C$ 57, before suspending in the organ bath, respectively. Then, aorta segments were suspended in organ baths(physiologic salt solution, 37$^{\circ}C$, 95% oxygen and 5% carbon dioxide) for Isometric tension recording. The vasodilatation to acetylcholine (10-2 to 10-2mol/L) was not impaired in control, 457, 4mST, nd 3757 groups. The vasodilatation to acetylcholine was impaired in endothelium removal group. The vasodilatation to sodium nitroprusslde (10-2 to 10-2 mol/L) was not impaired in all groups. In conclusion, both hyperkalemia and hypothermia do not alter irreversibly the function of the rondothelium of the thoracic aorta of the rat.

• Journal of Information Management
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• v.8 no.5
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• pp.130-140
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• 1975

이용자(利用者) 중심(中心)의 대화방식(對話方式) 시스팀을 개발(開發)하고 시험(試驗)하였다. 2년(年)동안 280개의 프로파일로 CA - Condensates 데이터 베이스내에서 정보(情報)를 검색(檢索)해 보았다. 그 시스팀의 작업능률(作業能率)을 사용(使用)한 데이터 베이스와 하드웨어의 구조(構造), 소프트웨어 패키지, 이용자(利用者)의 수(數), 그리고 정보(情報)센터에서 제공(提供)한 보조(補助)에 따라 평가(評價)하였다. 대화식(對話式) 검색방법(檢索方法)이나 이용자(利用者)의 요구(要求)를 양화(量化)하는 것, 그리고 여러가지 분야별(分野別)로 검색(檢索)하는 방법(方法) 등 이용자(利用者)의 요구(要求)를 보다 충실(充實)하게 만족(滿足)시킬 수 있는 여러가지 방법(方法)들을 논의(論議)하였다. 모든 정보(情報)시스팀의 목적(目的)은 적시(適時)에 올바른 정(情)보를 적자(適者)에게 제공(提供)하는 것이라고 잘 알려져 있다. 다시 말해서, 정보(情報)시스팀의 주요목적(主要目的)은 이용자(利用者)의 요구(要求)를 충족(充足)시켜 주는 것이다. 이러한 관념(觀念)의 변화(變化)는 정보처리(情報處理)에 큰 변화(變化)를 가져와 정보(情報)시스팀의 적응성(適應性)을 증가(增加)시키기 위해 여러 가지 새로운 방법(方法)들이 개발(開發)되었다. 정보(情報)시스팀들 사이의 상호작용(相互作用), 사람과 컴퓨터와의 대화(對話), 그리고 컴퓨터의 조력(助力)으로 이용자(利用者)의 프로파일을 작성(作成)하는 것 등은 이용자(利用者)의 요구(要求)를 존중(尊重)하고, 필요(必要)한 정보(情報)를 쉽게 찾기 위해서 고안(考案)된 것이다. 한편, 우리들은 이용자(利用者)의 특성(特性)이나 배경(背景), 그리고 문헌(文獻)에 대한 그의 습성(習性) 등에 대해서 얼마나 모르고 있는가를 깨닫게 된다. 상기(上記)의 내용(內容)을 요약(要略)하면, 근대정보(近代情報) 시스팀은 다음의 필요조건(必要條件)을 만족(滿足)해야 한다. 1) 이용자(利用者)의 요구(要求)에 호응(呼應)하기 위해서 적합(適合)한 일련(一連)의 정보(情報)를 제공(提供)해야 한다. 2) 이용자(利用者)와의 관계(關系)에서 시스팀은 적극적(積極的)이어야 한다. 즉, 프로파일 검색공식(檢索公式)에서 유발(誘發)되는 잘못을 지시(指示)하고 지적(指適)할 수 있어 야 한다. 나아가서 컴퓨터의 조력(助力)으로 프로파일을 작성(作成)하고 쉽게 수정(修正)할 수 있는 바람직하다. 우리들은 상기(上記)한 필수조건(必須條件)에 일치(一致)하도록 노력(努力) 하고 Bratislava에 위치(位置)하고 있는 슬로박 과학원(科學院)의 무기화학연구소(無機化學硏究所)와 화학공업경제연구소(化學工業經濟硏究所)가 공동(共同)으로 개발(開發)한 시스팀이 상기(上記)의 특수성(特殊性) 최소(最少)한 몇가지 도입(導入)하였다. 시스팀은 CACS라는 작업명하(作業名下)에서 운영(運營)되었다. 대략 15개월동안 280여개의 프로파일로 CA- Condensates 데이터베이스에서 정보(情報)를 검색(檢索)하여 이용자(利用者)들에게 최신정보(最新情報) 주지사업(周知事業)을 해 보았다. 우리들은 시스팀의 작업능률(作業能率)을 평가(評價)하고 이용자(利用者)의 요구(要求)를 만족(滿足)시키는 최선(最善)의 방법(方法)을 모색(摸索)하였다. 우선 이용자(利用者)와 시스팀사이를 밀접(密接)하게 연결(連結)하는데 중점(重點)을 두었다. 작업능률(作業能率Z)을 분석(分折)해 보고 우리들은 효율(效率)에 영향(影響)을 주는 인자(因子)는 다음의 4가지 주요분류(主要分類)에 속한다는 결론(結論)을 얻었다. (1) 검색(檢索)하는 데이터 베이스 (2) 情報시스팀, 소프트웨어 패키지 그리고 하드웨어 구조(構造) (3) 이용자(利用者)의 특성(特性)과 그의 요구(要求) (4) 정보(情報)센터가 이용자(利用者)에게 제공(提供)하는 보조(補助)

• Restorative Dentistry and Endodontics
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• v.21 no.2
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• pp.652-663
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• 1996

The purpose of this study was to evaluate the tensile bond strength to tooth structure of composite resin and glass ionomer cement according to filling methods and light curing units. In this study, two class V cavities were prepared on the buccal surface of each tooth of 140 extracted human molars, and they were randomly assigned into 3 experimental groups with 40 teeth and control group with 20 teeth. And then, each experimental groups subdivided into 2 groups(A,B) according to light curing units. The cavities of each group were filled with the CLEARFIL FII self curing resin(Control Group), Z-100 light curing resin(Group 1), Vitremer$^{TM}$ light curing glass ionomer cement(Group 2) and Z-100 light curing resin over the Vitrebond$^{TM}$ liner(Group 3). And subdivided A Group used Argon Laser(SPECTRUM$^{TM}$, U.S.A.), B Group used XL 1,000 curing light (3M, U.S.A.). The specimens underwent temperature changed from $5^{\circ}C$ to $55^{\circ}C$ five hundred times. After thermocycling, specimens were stored in 100% relative humidity at $37^{\circ}C$ for 24 hours. And then, the tensile bond strength of specimens were calculated with Universal Testing Machine(AGS-100A, Japan). The results were as follows : 1. Among the experimental groups, the group 2-B showed the highest tensile bond strength ($18.89{\pm}7.80$) and the group 1-A showed the lowest tensile bond strength ($11.68{\pm}2.28$). There was significant difference between group 2-B and group 1-A(p<0.01). 2. Between the light curing units, the XL 1,000 unit showed higher tensile bond strength ($16.63{\pm}3.20$) than that of the Argon Laser unit ($13.73{\pm}2.30$). There was significant difference between XL 1,000 and Argon Laser(p<0.01). 3. About filling methods and materials, the group 2 showed the highest tensile bond strength ($17.56{\pm}1.89$) and the group 1 showed the lowest tensile bond strength($13.03{\pm}1.90$). There was significant difference between group 2 and group 1,3(p<0.01). In conclusion, the results showed that the glass-ionomer cement that cured by XL 1,000 light curing unit demonstrated significantly higher tensile bond strength than other curing unit and filling methods.

• Journal of radiological science and technology
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• v.45 no.2
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• pp.135-143
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• 2022

In SPECT image, scatter count is the cause of quantitative count error and image quality degradation. This study is to evaluate the accuracy of CT based SC(CTSC) and energy window based SC(EWSC) as the comparison with existing Non SC. SPECT/CT images were obtained after filling air in order to acquire a reference image without the influence of scatter count inside the Triple line insert phantom setting hot rod(^99mTc 74.0 MBq) in the middle and each SPECT/CT image was obtained each separately after filling water instead of air in order to derive the influence of scatter count under the same conditions. For EWSC, 9 sub-energy windows were set additionally in addition to main energy window(140 keV, 20%) and then, images were acquired at the same time and five types of EWSC including DPW(dual photo-peak window)10%, DEW(dual energy window)20%, TEW(triple energy window)10%, TEW5.0%, TEW2.5% were used. Under the condition without fluctuations in primary count, total count was measured by drawing volume of interest (VOI) in the images of the two conditions and then, the ratio of scatter count of total counts was calculated as percent scatter fraction(%SF) and the count error with image filled with water was evaluated with percent normalized mean-square error(%NMSE) based on the image filled with air. Based on the image filled with air, %SF of images filled with water to which each SC method was applied is non scatter correction(NSC) 37.44, DPW 27.41, DEW 21.84, TEW10% 19.60, TEW5% 17.02, TEW2.5% 14.68, CTSC 5.57 and the scatter counts were removed the most in CTSC and %NMSE is NSC 35.80, DPW 14.28, DEW 7.81, TEW10% 5.94, TEW5% 4.21, TEW2.5% 2.96, CTSC 0.35 and the error in CTSC was found to be the lowest. In SPECT/CT images, the application of each scatter correction method used in the experiment could improve the quantitative count error caused by the influence of scatter count. In particular, CTSC showed the lowest %NMSE(=0.35) compared to existing EWSC methods, enabling relatively accurate scatter correction.

• Journal of Korean Neurosurgical Society
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• v.65 no.2
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• pp.269-275
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• 2022

Objective : The coronavirus disease 2019 (COVID-19) pandemic is affecting the characteristics of patients with head injuries. This study aimed to evaluate the effect of the COVID-19 pandemic on patients with head injuries at a regional emergency medical center in South Korea. Methods : From April 2019 to November 2020, 350 patients with head injuries were admitted to our hospital. The study period was divided into the pre-COVID-19 (n=169) and COVID-19 (n=181) eras (10 months each). Patients with severe head injuries requiring surgery (n=74) were categorized into those who underwent surgery (n=41) and those who refused surgery (n=33). Results : Head injuries in pediatric patients (<3 years) were more frequent in the COVID-19 era than in the pre-COVID-19 era (8.8% vs. 3.6%, p=0.048). More patients refused surgery in the COVID-19 era than in the pre-COVID-19 era (57.9% vs. 30.6%, p=0.021). Refusal of surgery was associated with old age (67.7±14.5 vs. 52.4±19.1, p<0.001), marital status (married, 84.8% vs. 61.0%, p=0.037), unemployment (42.4% vs. 68.3%, p=0.034), COVID-19 era (66.7% vs. 39.0%, p=0.021), and lower Glasgow coma scale scores (6.12±3.08 vs. 10.6±3.80, p<0.001). Multivariable logistic regression analysis revealed that refusal of surgery was independently associated with old age (adjusted odds ratio [OR], 1.084; 95% confidence interval [CI], 1.030-1.140; p=0.002), COVID-19 era (adjusted OR, 6.869; 95% CI, 1.624-29.054; p=0.009), and lower Glasgow coma scale scores (adjusted OR, 0.694; 95% CI, 0.568-0.848; p<0.001). Conclusion : We observed an increased prevalence of head injuries in pediatric patients (<3 years) during the COVID-19 pandemic. Additionally, among patients with severe head injuries requiring surgery, more patients refused to undergo surgery during the COVID-19 pandemic.