• Journal of Radiation Protection and Research
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• v.44 no.2
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• pp.79-88
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• 2019

Background: The main goal of experiments is to compare various operational and technical characteristics of D-Shuttle semiconductor personal dosimeters of the Japanese company "Chiyoda Technol Corporation" and Harshaw thermoluminescent dosimeters (TLD) manufactured by "Thermo Fisher Scientific" and DTL-02 of the Russian Research and Production Enterprise (RPE) "Doza" by their occupational and calibration exposure at various dose equivalents from 0.5 to 20 mSv of gamma-radiation. Materials and Methods: Besides dosimeters DTL-02, D-Shuttle and Harshaw TLD, there were also used: (1) the primary reference radionuclide source Hopewell Designs IAEA: G10-1-12 with $^{137}Cs$ isotope (an error is not more than 6% and activity is 20 Ci), and (2) the verification device UPGD-2M of RPE "Doza" and installed in the National Center for Expertise and Certification of the Republic of Kazakhstan (Kapchagai, the National Center for Expertise and Certification). Results and Discussion: The main results of researches are the following: (1) TLDs for Harshaw 6600 and DVG-02TM have an approximately equal measurement accuracy of the individual dose equivalents in the range from 0.5 to 20 mSv of gamma-radiation. (2) Advantages of dosimeters for Harshaw 6600 are due to the high measurement productivity and opportunity to indicate the dose on the skin $H_p$(0.07). Advantages of DVG-02TM consist of operation simplicity and lower cost than of Harshaw 6600. (3) D-Shuttles are convenient for use in the current and the operational monitoring of ionizing radiation. Measurement accuracy and 10% linearity of measurements are ensured when D-Shuttle is irradiated with dose equivalents below 1 mSv at the equivalent dose rate not higher than $3mSv{\cdot}hr^{-1}$. This allows using D-Shuttle at a routine technological activity. Conclusion: The obtained results of experiments demonstrate advantages and disadvantages of D-Shuttle semiconductor dosimeters in comparison with two TLD systems of DVG-02TM and Harshaw 6600.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.50
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• pp.65-73
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• 1999

Most psychophysical studies in manual material handling (MMH) have paid more attention to two-handed MMH activities than to one-handed MMH activities. Also, studies are involved only with single MMH activities - lifting, lowering, carrying, holding, pushing or pulling. Very few studies are reported on the determination of workers' capacities for combinations of one-handed MMH activities (lifting a box, then carrying the box, and lowering the box). The objective of this study was to find the psychophysical and physiological responses of human subjects from a simulated industrial task involving one-handed and two-handed combined tasks. The capacities that were determined as the maximum acceptable weight workloads for 1 hr work period for one-handed and two-handed combined tasks - lifting a box from floor to knuckle height, carrying the box for 4.3 m, and lowering the box from knuckle to floor height - were determined psychophysically under three frequencies: six handlings per minute, one handling per minute and one handling per five minutes. In addition to maximum acceptable weight, heart rate and RPE values on wholebody, back, and arm were also measured as responses.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.5
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• pp.320-323
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• 2018

SiGe thin films were deposited by remote plasma enhanced chemical vapor deposition (RPE-CVD) at $400^{\circ}C$ using $SiH_4$ or $SiCl_4$ and $GeCl_4$ as the source of Si and Ge, respectively. The growth rate and the degree of crystallinity of the fabricated films were characterized by scanning electron microscopy and Raman analysis, respectively. The optical and electrical properties of SiGe films fabricated using $SiCl_4$ and $SiH_4$ source were comparatively studied. SiGe films deposited using $SiCl_4$ source showed a lower growth rate and higher crystallinity than those deposited using $SiH_4$ source. Ultraviolet and visible spectroscopy measurement showed that the optical band gap of SiGe is in the range of 0.88~1.22 eV.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.69-78
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• 2002

This paper examines the effects on mental fatigue of changes in the intensity of physical activity. A treadmill-equipped instrument and perception tester were used to attain several levels of physical activity In this paper, In order to determine the individual levels of physical activity of subjects, Borg-RPE scale, Heart Rate(HR) and Respiratory Quotient(RQ) were used. Also, an addition test in whole-body activity on treadmill-equipped instrument as an indicator of mental fatigue were performed. In the above experiments, the scores obtained in addition test administered before and after physical activity at each intensity level used. Restricted within the limits of this paper, the results of these tests showed that mental fatigue decreased after physical activity.

• Molecules and Cells
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• v.41 no.4
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• pp.257-263
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• 2018

Vertebrate organ development is accompanied by demarcation of tissue compartments, which grow coordinately with their neighbors. Hence, perturbing the coordinative growth of neighboring tissue compartments frequently results in organ malformation. The growth of tissue compartments is regulated by multiple intercellular and intracellular signaling pathways, including the Hippo signaling pathway that limits the growth of various organs. In the optic neuroepithelial continuum, which is partitioned into the retina, retinal pigment epithelium (RPE) and ciliary margin (CM) during eye development, the Hippo signaling activity operates differentially, as it does in many tissues. In this review, we summarize recent studies that have explored the relationship between the Hippo signaling pathway and growth of optic neuroepithelial compartments. We will focus particularly on the roles of a tumor suppressor, neurofibromin 2 (NF2), whose expression is not only dependent on compartment-specific transcription factors, but is also subject to regulation by a Hippo-Yap feedback signaling circuit.

• Journal of the Korean Society of Tobacco Science
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• v.31 no.2
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• pp.95-106
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• 2009

Semiquantitative analysis by ICP-MS has proven to be a powerful tool for fast screening, in addition, it does not require the element of interest to be present in the calibration standard, making it especially useful for the analysis of unknown samples. In this study, seven cigarette samples were analyzed by the rapid semi-quantitative analysis method based on the ICP-MS. For each cigarette sample, cut tobacco, cigarette paper, filter (before and after smoking), and smoke condensate were analyzed. The accuracy of the analysis technique was evaluated by comparing results obtained from Calibration Check Standard(CCS) and calibration method. Relative Percentage Error(RPE) value of all elements measured for three CCS showed a stable result of less than ${\pm}20%$. Compared to full quantitative analysis by calibration method, the results for cigarette samples showed average error within ${\pm}15%$.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.69
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• pp.51-64
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• 2001

A laboratory experiment was conducted to investigate the effects of working posture. work/rest ration, and task type on the physical workload in automobile assembly jobs. Ten healthy male university students participated as subjects in the experiment. East subject performed 18 experimental session with combination of 3 working posture 3 work/rest ratio and 2 task types. To examine the effect of various working conditions on workload, DMG analysis was performed on 4 different muscles in the neck an arm area, Also RPE scale and heart rate were taken as response variables. The result showed that all working conditions considered in the experiment had significant effects on the workload concluding that labor intensity in auto assembly jobs should be adjusted with respect to different levels of working posture, work/rest ratio, and task type. Detailed analysis are presented in the paper.

• Journal of The Korean Ophthalmological Society
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• v.59 no.12
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• pp.1190-1194
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• 2018

Purpose: We report a case of unilateral, focal, pigmented paravenous retinochoroidal atrophy (PPRCA). Case summary: A 46-year-old female visited our clinic in complaint of a vague problem with her right eye identified during a general medical examination. The visual acuity (without correction) of both eyes was 1.0. Slit-lamp examination of both eyes revealed no specific signs. Fundus examination of the right eye revealed focal, bony-spicule-shaped retinochoroidal atrophy with pigmentation along the course of the superior retinal vein. A fundus autofluorescence examination revealed principally hypofluorescence with some hyperfluorescence at the margin of the atrophic retinochoroidal lesion. Optical coherence tomography revealed mixed clumping and atrophy of the retinal pigment epithelium (RPE) layer and thinning of the choriocapillaris layer. Fluorescence angiography revealed a window defect and blockage at the site of the lesion (the fluorescent material did not enter the lesion). The site of the window defect was in correlation with the atrophic RPE region. The site of the blockage at lesion also matched with the site of the regional pigment clumping. No definite leakage was observed. Conclusions: To the best of our knowledge, this is the first case of unilateral focal PPRCA reported from Korea.

• Journal of the Ergonomics Society of Korea
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• v.15 no.2
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• pp.177-184
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• 1996

In light-weight hand tools, static posture may result in postural fatigue. Psotural tremor of the upper extremity in a static posture was measured to provide guidelines for hand tool weight. Postural tremor was measured on five levels of tool weitht : no weight, 400g, 800g, 1200g, and 1600g. Three types of camcorder recording postures were selected. For each condition, postural tremor was measured together with ENG of biceps, deltoid and pectoralis major, and Borg's CR-20 ratings of perceved exertion. Results of the experiment are as follows : frequency analysis of tremor revealed increased amplitude of frequency bands of 2-4Hz and 10-14Hz. Postural tremor of the upper extremeity maintained the initial level until fatigue developed. After the development of fatigue, the rate of change of postural tremor significantly increased. Different tool weights and hand postures showed different rates of tremor increase. Time tp fatigue and corresaponding endurance time were positively correlated with Borg's RPE scores.

• Journal of Life Science
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• v.18 no.7
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• pp.986-991
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• 2008

The purpose of this study was to investigate the effect of Taekwondo and calcium intake on physique, growth hormone and IGF-1 in elementary school male students. 24 subjects who the fourth grade and Taekwondo black belt ($1{\sim}2$ poom) were classified into three groups; Taekwodo +calcium intake group (8), Taekwondo group (8) and control group (8). The period of Taekwondo was 12 weeks, 5 times a week and each time 50 minutes with RPE ($7{\sim}15$) for intensity were treated and subjects were given calcium at 750 mg of pill after dinner a day during the 12 weeks. The conclusions of this study are as follows; In the comparison within each group, three groups all significantly increased in body height but in the comparison between groups, A and B groups were more significantly increased in body height than C. C significantly decreased in growth hormone and in the comparison between groups, A and B groups were more significantly increased in growth hormone than C. In the comparison within each group, A and B significantly increased in IGF-1 and in the comparison between groups, A and B groups were more significantly increased in IGF-1 than C. It is considered that Taekwondo and calcium intake give effects to body height by increasing growth hormone and IGF-1. It is necessary to continue the study, because the study results of growth hormone and IGF-1 are various by training method, intensity, nutrition.