• Journal of Aquaculture
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• v.5 no.2
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• pp.177-182
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• 1992

Experiments were conducted with goldfish exposed to various levels of mercuric chloride(control group) and mercuric chloride with chitosan (experimental group). Dilutions of these two solutions were made in the concentration ranges 0.6 to 1.0 $mg/{\ell}$ and 1.2 to 2.0 $mg/{\ell}$, respectively. Fifty percent lethal concentration of mercuric chloride($LC_{50}$) for 48 hours with the species was between 0.6 and 0.7 $mg/{\ell}$. Exposure of goldfish to mercury produced a marked, dose-dependent mortality with elevation of concentration (P<0.05). However, at each concentration of mercuric chloride treated with chitosan, mortality decreased significantly compared to control group (P<0.05).

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.482-495
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• 2006

The purpose of this study was to investigate the eating behavior and food preference of preschool children in day care facilities. Subjects of this study were 192 young children who lived in Sungnam city, Gyeonggi-Do. The results are summarized as follows: The parents reported that 34% of the children ate 'unbalanced diet'. And 16% of the children ate small portions of food. The parents picked up several reasons for their children's 'unbalanced diet' such as 'dislike of the tastes(29.2%), 'texture in the mouth(28.6%)', 'smell of food(18.2%)' Fifty-six percent of parents took 'to change the cooking methods' as the best way to make their children have good eating habits in their home. The highest score of preference among the children was noodles with bean sauce and kimbab for staple food, stews seaweed soup for soups and stews, bulgogi and fried chicken for side dish. The young children's preference score fur side dish made with meats were higher than made with vegetables. This study made a suggestion to parents of children ages 4 to 6 and to teachers in preschool that they prepare for foods made with vegetables.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.759-764
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• 2001

The separation performance of zigzag air classifier with angle of 90 degrees was studied using narrow size fractions of thin square samples and granular samples. The simulation results of air velocity inside the classifier indicated that the zigzag geometry induces a new pattern consisting of an upward flow and a circulation flow, Experimental results showed that overflow product recovery was described as an integral calculus of normal distribution as a function of dimensionless air velocity ( $V_{A}$ $V_{A50}$), where $V_{A}$ is superficial air velocity and $V_{A50}$ is the $V_{A}$ at the fifty percent recovery. The $V_{A}$ values were predicted using the equations derived from dynamics for a particle dropping in air. A monitoring system that utilizes changes in acoustic signals emitted during the process of air classification was developed to separate PET with desired recovery or grade. The technical feasibility of the on-line monitoring of the PET recovery and grade was demonstrated by measuring relative energy of the signals.signals.als.

• Radiation Oncology Journal
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• v.6 no.1
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• pp.13-22
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• 1988

This study is the retrospective evaluation of ninety-six patients with biopsy-proven carcinoma of nasopharynx treated with radiotherapy at Yonsei University, College of Medicine, Radiation Oncology from January 1971 to December 1985. Patient's age ranged from 15 to 71 years with a median age of 49 years. Fifty-two point five percent of local control and $47.5\%$ of actuarial 5 year survival were achieved with radical radiotherapy. Five year survival rate for Stage I&II, III and IV were $75.0\%,\;74.6\%\;and\;41.4\%$, respectively. Distant metastasis rate was related with N stage $(N1\;12.5\%,\;N1\;0\%,\;N2\;23.5\%,\;N3\;32.1\%$and histologic type (lymphoepithelioma $41.7\%$, squamous cell carcinoma $6.5\%$) but not with T stage. Thirty-one of sixty-seven patient covered adequate radiation field received induction chemotherapy. However induction chemotherapy does not appear to improve over all survival.

• Research in Community and Public Health Nursing
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• v.17 no.1
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• pp.17-25
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• 2006

Purpose: The goals of this research are to find out factors influencing the duration of work-related disability and to present implications for policies to prevent delayed recovery. Method: The subjects of this study were 238 workers who had been proved to be industrial disaster victims for occupational low back pain between January 1 2000 and December 31 2003. Kaplan-Meier method was used to estimate the proportion of duration of disability associated with low back pain, and Cox proportional hazards analysis was used to identify factors predicting it. The model distinguished main symptom variables affecting acute(${\leq}90\;days$) and chronic phase of disability (>90 days). Result: Fifty percent of the workers had not recovered in 408 days. The results of Cox regression show that delayed duration of disability was predicted by diagnosis, pain radiation (in chronic phase), sex, the size and labor union of the workplace, scheduled rest, compensation from the company, and operation. Conclusion: Duration of disability associated with compensated low back pain is influenced not only by factors related to the company and compensation system but also by individual factors. Thus, future efforts to reduce duration of disability may need to take into account all these factors.

• The Journal of Korean Academic Society of Nursing Education
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• v.23 no.3
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• pp.353-362
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• 2017

Purpose: This study aimed to analyze the mobility of newly graduated nurses from regions where their nursing schools were located to regions where they took up their first jobs, and to identify factors influencing nurses' mobility. Methods: Data from the Graduates Occupational Mobility Survey, collected annually from 2010 to 2014 by the Korea Employment Information Service, were analyzed. The sample consisted of 1,488 graduates and 1,229 nurses who were employed on a full-time basis in hospitals. Multiple logistic regression analysis was conducted to identify factors associated with geographic mobility. Results: Among the nurses working in hospitals, 69.2% had their first jobs in their nursing school regions and 11.3% in their high school regions. Fifty-two percent of the nurses worked in the capital region; 47.2% thereof had moved from a non-capital region. Nurses were more likely to work in their nursing school region when they were female, were older, graduated from a high school located in their nursing school region, graduated from a college (vs. university), had a lower nursing school performance, and expected lower monthly wage, compared with those who left their nursing school region. Conclusion: Education and remuneration policies are required to reduce geographical mobility to the capital region.

• Imaging Science in Dentistry
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• v.35 no.4
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• pp.203-205
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• 2005

Purpose: This study was aimed to compare skin entrance dose of digital radiography with that of film radiography and to show the dose reduction achievement with digital systems at 11 dental schools in Korea. Materials and Methods: Forty six intraoral radiographic systems in 11 dental schools were included in this study. Digital sensors were used in 33 systems and film was used in 13 systems. Researchers and the volunteer visited 11 dental schools in Korea. Researchers asked the radiologic technician (s) at each school to set the exposure parameters and aiming the x-ray tube for the periapical view of the mandibular molar of the volunteer. The skin entrance doses were measured at the same exposure parameters and distance by the technician for each system with a dosimeter (Multi-O-Meter : Unfors instruments, Billdal, Sweden). Results: The median dose was $491.2{\mu}Gy$ for digital radiography and $1,205.0{\mu}Gy$ for film radiography. The skin entrance dose in digital radiography was significantly lower than that of film radiography (p<0.05). Conclusion: Fifty-nine percent skin entrance dose reduction with digital periapical radiography was achieved over the film radiography in Korean dental schools.

• BMB Reports
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• v.31 no.2
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• pp.144-148
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• 1998

A bifunctional catalase-peroxidase, designated catalase-2, of a UV resistant Deinococcus radiophilus was purified to electrophoretic homogeneity by both chromatographic and electrophoretic methods. Its molecular weight was 310 kDa and composed of a tetramer of 80 kDa subunits. The catalase-2 exerted its optimal activity at $30^{\circ}C$ and around pH 9. Its $K_m$ value for $H_{2}0_{2} $ was about 10 mM. It showed the typical ferric heme spectrum with maximum absorption at 403 nm which shifted to 419 nm in the presence of cyanide. The ratio of A40i' A2S0 was 0.48. Fifty percent inhibition of the enzyme activity was observed at $4.6{\times}10^{-6}$, $7.7{\times}10^{-6}$, and $3.0{\times}10^{-6}$ M of NaCN, $NaN_3$, and $NH_{2}OH$, respectively. The enzyme was thermostable and not sensitive to 3-amino-1,2,4-triazole. Treatment of the enzyme with ethanol-chloroform caused a partial loss (30%) of its activity. The catalase-2 was distinct from the Deinococcal bifunctional catalase-3 in a number of properties, particularly in its molecular structure and substrate affinity.

• Journal of Labour Economics
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• v.23 no.2
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• pp.81-106
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• 2000

This paper examines whether 'abnormal work practices', which have rapidly increased since the mid 1990s, are a 'bridge' for workers to 'normal work practices' or a 'trap' from which they are hard to escape. It provides both the static and dynamic analysis. The former shows they are likely to work as a 'trap'. The latter, which investigates the transition probability during the last 24 months, also supports the same result. It finds out that most of part-time workers paid by an employer are contingent workers or daily workers and that about fifty percent of 'abnormal workers' took them involuntarily.

• Journal of Astronomy and Space Sciences
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• v.3 no.2
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• pp.103-116
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• 1986

The mass distribution and other related quantities were calculated by fitting the observed rotation curve(Davoust and de Vaucouleur 1980) to Brandt and Belton's mass distribution model. One of n values for mass model is determined as 1.5(Vm=95 $kms^{-1}$) and two pairs of them are determined as 0.8(Vm = 95$kms^{-1}$) and 2.0 and 0.8 (Vm = 55$kms^{-1}$) and 2.0 because of the hump in observed rotation curve. Total masses and integrated mass to luminosity ration are $1.8\times10^{10}M_\odot,\;1.5\times10^{10}M_\odot,\;1.4\times10^{10}M_\odot$, and 6.57, 5.33, 5.26 for three cases according to n values. Integrated mass to luminosity ratio in Holmberg radius is 3.44, 3.26, 3.00 in god agreement with the typical value of Sd type suggested by Faber and Gallagher(1979). Presented halo masses which are fifty percent of total masses and halo mass to luminosity ratios given as 75.83, 53.50, 58.75 are values less than Turner's(1976).