• Progress in Medical Physics
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• v.11 no.2
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• pp.123-130
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• 2000

The performance of an electrometer directly affects on the accuracy and precision in radiation dosimetry. This study is to list of the quality control for maintaining performance and to perform evaluation tests of an electrometer. Performance tests selected include proper polarizing voltages, warm-up and equalization time, leakages, long-term stability, linearity, and effect of ambient conditions. An electrometer connected with a rigid stem ionization chamber was evaluated with a Strontium-90 check device. Bias voltage was measured directly on the input socket. Equalization time is the time required for reaching threshold of charged state after the power is on or the bias voltage is changed. Pre- and post-signal leakages are defined as the accumulation of signal with no exposure and after exposure, respectively. Over three months period, the electrometer's long-term stability was measured by comparison of the temperature-pressure corrected readings. Linearity was expressed as the deviation of readings from multiple short exposures from one continuous exposure. Effect of ambient conditions was expressed as the zero drift of the electrometer over 17-34$^{\circ}C$ temperature ranges. For two nominal values, 300 and 500 volts, measured voltages were lower by 2.5 and 5.8%, respectively. The warm-up time, 20 minutes, was longer than the lamp time by 9 minutes and the equalization time was less than 1 minute. Without exposure, the zero-drift was 0.002 scale-unit in 15 minutes and the leakage after 10 minutes exposure was minimal. The IQ-4 was stable over 99.4% for three-month periods. Deviation from the linearity was 0.9% for measurement scale, 0.000-9.991. Over 17-34$^{\circ}C$ temperature range, the zero-drift was minimal, less than 0.2%. For a clinically-used electrometer, a list for the basic peformance evaluations is proposed. By running this program, the measurement error using an electrometer can be reduced and in turn the improvement in accuracy and precision of radiation dosimetry can be achieved.

• Korean Journal of Ichthyology
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• v.19 no.1
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• pp.1-7
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• 2007

The effect of water temperature (T) and body weight (W) on the oxygen consumption of the fasted black rockfish, Sebastes schlegeli was investigated to provide empirical data for the culture management and bioenergetic growth model of this species. The mean wet body weights of two fish groups used for the present experiment were $12.9{\pm}2.7g$ ($mean{\pm}SD$) and $351.1{\pm}9.2g$. The oxygen consumption rate (OCR) was measured under three water temperature regimes (15, 20 and $25^{\circ}C$) at an interval of 5 minutes for 24 hours using a continuous flow-through respirometer. In each treatment three replicates were set up and 45 fish in small size groups and 6 fish in large size groups were used. The OCRs increased with increasing water temperature in both size groups (p<0.001). Mean OCRs at 15, 20 and $25^{\circ}C$ were 414.2, 691.5 and $843.8mg\;O_2\;kg^{-1}h^{-1}$ in small size groups, and 182.0, 250.7 and $328.2mg\;O_2\;kg^{-1}h^{-1}$ in large size groups, respectively. The OCRs decreased with increasing body weights in three water temperature groups (p<0.001). The mass effect on metabolic rate can be expressed by the power of 0.69~0.75. The data are best described by the relationship: OCR=89.12+28.79T-1.17W. $Q_{10}$ values ranged 1.90~2.79 between 15 and $20^{\circ}C$, 1.49~1.71 between 20 and $25^{\circ}C$, and 1.80~2.03 over the full temperature range, respectively. The energy loss by metabolic cost increased with increasing water temperature and decreasing body weight (p<0.001). Mean energy loss rates by oxygen consumption at 15, 20 and $25^{\circ}C$ were 282.9, 472.3 and $576.3kJ\;kg^{-1}d^{-1}$ in small size groups and 124.3, 171.3 and $224.1kJ\;kg^{-1}d^{-1}$ in large size groups, respectively.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.4
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• pp.446-453
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• 2020

The purpose of this study was to evaluate the effect of Indocyanine Green (ICG) and near-infrared (NIR) diode laser on Streptococcus mutans biofilms depending on ICG concentrations. S. mutans biofilms were formed on a Hydroxyapatite disk, and 0.5, 1.0, 2.0, 3.0, 4.0, 5.0 mg/mL ICG solutions dissolved in sterile distilled water and a NIR diode laser having a power of 300 mW and a wavelength of 808 nm were applied to the biofilms. The temperature changes of the biofilm surface according to the concentrations of the ICG solution were measured using a 1-channel thermocouple thermometer. Compared to the control group, in the groups with only the 3.0, 4.0, 5.0 mg/mL ICG solution application, and in the groups with the 1.0, 2.0, 3.0, 4.0, 5.0 mg/mL ICG solution application and light irradiation, a statistically significant decrease in the bacterial counts were observed. The temperature increase according to the concentration of the ICG solutions was 9.53℃, 10.43℃, 11.40℃, 12.10℃, 12.67℃, and 13.63℃ in ICG solutions of 0.5, 1.0, 2.0, 3.0, 4.0, and 5.0 mg/mL respectively. This study presents the potential for clinical application of ICG and NIR diode lasers as a new method for preventing dental caries.

• Management & Information Systems Review
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• v.34 no.2
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• pp.131-149
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• 2015

Recently many organizations have engaged in widespread restructuring as well as more flexible usage of labor in an attempt to cut costs and to increase profit. As a result of lays offs resulting from frequent restructuring, many people no longer consider their jobs as permanent positions. many employees have an increased feeling of job insecurity. There structuring and following downsizing have created an uncertain environment within creased fear offer ther job losses. therefore the study of job insecurity is significant. especially To understand the relationship between job security and union-relation behaviors on the industrial relations. The purpose of this study suggested the strategies to company and union. The purpose of this study is to examine how the union-relation behaviors are influenced by the job security. This study built a exploratory model that there is causal relationship of job security to union commitment, dual commitment, and labor related behaviors. For the verification of this study model, the regression analysis was applied to the surveys of 236 members of union that are located in Busan, Gyeongnam, Ulsan, and Pohang. The result of this research shows that the job insecurity is strongly related to the union commitment and union related behaviors. According to the research, the effect that the job security affects union commitment and union related behaviors are positive. With the research outputs, we have discussed about the academic and pragmatic viewpoint. We proposed comprehensive model to verify how the job insecurity affects the union-related behaviors, and objectively analyzed the model. The research result was opposite to what the existing theories have said that high job insecurity derives high union-related behaviors. This result is meaningful because it is concerned with the social issues-present situation of Korean company, low-employment, unstable employment and so on. Moreover, this research may contribute to expand the aspect of academic research on job insecurity as there are few research conducted in korea. This research also suggests the realistic alternative of union-related behaviors because it is proved that job security can contribute to innovation activities. Also, this research implies that the matter of job insecurity is the basic need of organizational individual and presents that job security is not a notion but the alternative by using of the positional stability and situational control power. The limitation of this research is that it is only utilized the cross-sectional study. To remedy the cross-sectional study, vertical, and serial method of research is needed. And there is no enough sample to secure more comprehensive data as the targets of the research is limited to Busan and Gyeongnam regions. Finally, the measurement tool for job security is needed to be suitably modified to by the South Korea's economic, linguistic, and cultural situation.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.7
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• pp.7-14
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• 2009

In this paper, the effects of annealing conditions on the structural ((002) intensity, FWHM, d-spacing, grain size, (002) peak position), optical (UV peak, UV peak position) and electrical properties (carrier concentrations, resistivity, mobility) of ZnO films were investigated. ZnO films were deposited onto SiO$_2$/si substrates by RF magnetron sputtering from a ZnO target. The substrate was not heated during deposition. ZnO films were annealed in temperature ranges of $500\sim650^{\circ}C$ in the O$_2$ flow for 5$\sim$20 min. The film average thicknesses were in the range of 291 nm. The surface morphologies and structures of the samples were characterize by SEM and XRD, respectively. The optical properties were evaluated by photoluminescence (PL) measurement at room temperature (RT) using a He-Cd 325 nm laser. As the annealing temperature and time vary, the following relations were also observed: (1) proportional relationships among UV intensity (002) intensity, and grain size exist, (2) UV intensity is inversely proportional to FWHM, (3) there is no special relationship between UV intensity and electron carrier concentrations, (4) d-spacing is inversely proportional to (002) peak position, (5) UV peak position in the range of 3.20$\sim$3.24 eV means that ZnO films have a n-type conductivity which was consistent with that obtained from the electrical property, (6) the optimal conditions for the best optical and structural characteristics were found to be oxygen fraction, (O$_2$/(O$_2$+Ar)) of 0.2, RF power of 240W, substrate temperature of RT, annealing condition of 600$^{\circ}C$ for 20 min, and sputtering pressure of 20 mTorr.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.4
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• pp.227-234
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• 2019

This study was performed to investigate the effect of heat-stressed environment on rumen microbial diversity in Holstein cows. Rectal temperature and respiration rate were measured and rumen fluid was collected under normal environment (NE; Temperature humidity index (THI)=64.6) and heat-stressed environment (HE; THI=87.2) from 10 Holstein cows (60±17.7 months, 717±64.4 kg) fed on the basis of dairy feeding management in National Institute of Animal Science. The rumen bacteria diversity was analyzed by using the Illumina HiSeq^TM 4000 platform. The rectal temperature and respiratory rate were increased by 1.5℃ and 53 breaths/min in HE compared to that in NE, respectively. In this study, HE exposure induced significant changes of ruminal microbe. At phylum level, Fibrobacteres were increased in HE. At genus level, Ruminococcaceae bacterium P7 and YAD3003, Butyrivibrio sp. AE2032, Erysipelotrichaceae bacterium NK3D112, Bifidobacterium pseudolongum, Lachnospiraceae bacterium FE2018, XBB2008, and AC2029, Eubacterium celulosolvens, Clostridium hathewayi, and Butyrivibrio hungatei were decreased in HE, while Choristoneura murinana nucleopolyhedrovirus, Calothrix parasitica, Nostoc sp. KVJ20, Anabaena sp. ATCC 33047, Fibrobacter sp. UWB13 and sp. UWB5, Lachnospiraceae bacterium G41, and Xanthomonas arboricola were increased in HE. In conclusion, HE might have an effect to change the rumen microbial community in Holstein cows.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.2
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• pp.67-75
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• 2012

Carbon-dioxide capture and storage (CCS) process is consisted by capturing carbon-dioxide from large point source such as power plant and steel works, transporting and sequestrating captured $CO_2$ in a stable geological structure. During CCS process, it is inevitable of introducing impurities from combustion, capture and purification process into $CO_2$ stream. Impurities such as $SO_2$, $H_2O$, CO, $N_2$, Ar, $O_2$, $H_2$, can influence on process efficiency, capital expenditure, operation expense of CCS process. In this study, experimental apparatus is built to simulate the behavior of $CO_2$ transport under various impurity composition and process pressure condition. With this apparatus, $N_2$ impurity effect on $CO_2$ mixture transportation was experimentally evaluated. The result showed that as $N_2$ ratio increased pressure drop per mass flow and specific volume of $CO_2-N_2$ mixture also increased. In 120 and 100 bar condition the mixture was in single phase supercritical condition, and as $N_2$ ratio increased gradient of specific volume change and pressure drop per mass flow did not change largely compared to low pressure condition. In 70 bar condition the mixture phase changed from single phase liquid to single phase vapor through liquid-vapor two phase region, and it showed that the gradient of specific volume change and pressure drop per mass flow varied in each phase.

• Journal of Haehwa Medicine
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• v.10 no.1
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• pp.453-469
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• 2001

This study attempted to analyze the contents of the research papers concerning the diagnosis and treatment of Alzheimer-type dementia presented in the magazine of Chinese Medicine published in China over the period between 1998 and 2000. As a result, the following conclusion was drawn: 1. The Chinese medical category of Alzheimer-type dementia includes amnesia, dementia, stupidity, depression symptom complex, insanity and the like and uses the as the criterion for diagnosis and treatment effect evaluation. 2. The clinical symptoms of Alzheimer-type dementia include lowered intelligence, deterioration of memory, understanding and judgemental power, retardation of the reaction, emotional changes, character changes, behavioral changes and the like and are divided into mild, medium and serious according to the degree of symptom. 3. From the perspective of Bon-Heo-Pyo-Shil(state of deficient vital essence and excessive pestilential vapor), the pattern of Byun-Sung(identification) is divided into deficiency symptom complex, excessive symptom complex and indiscernible fullness and emptiness. The deficiency symptom complex includes deficiency of the liver and kidney, deficiency of essence of the kidney, deficiency of the reservoir of marrow and the like. The excessive symptom complex includes internally blocked stagnant blood, blocking of the passageway due to turbid phlegm, blood stasis due to stagnation of chi, and the like. The indiscernible fullness and emptiness symptom complex includes the deficiency of essence of kidney, blocking of the passageway due to stagnant phlegm, blood stasis due to the deficiency of kidney, blood stasis due to the deficiency of heart and the like. 4. The therapeutics and' prescription of Alzheimer-type dementia include the following: Bo-Shin-Ik-Su-Tang for tonifying the kidney, replenishing the marrow and plugging the essence; Ki-Guk-Ji-Hwang-Hwan-Ga-mi for reinforcing the vital essence of the liver and kidney; Kwi-Bi-Tang-Hap-Yang-Shim-Tang for invigorating the functioning of the spleen and nourishing the heart; Hyel-Bu-Chuk-Eo-Tang-Ga-Mi for activating the blood and resolving the stagnancy of the blood; Bo-Yang-Hwan-Oh-Tang for replenishing chi, activating the blood and resolving the stagnancy of the blood; Beoh-Kwang-Mong-Sung-Tang for invigorating the functioning of the spleen, replenishing the kidney, resolving the phlegm and enlivening the brain; n-Dam-Tang-Ga-Mi for invigorating the functioning of the spleen, replenishing chi, and removing the phlegm and unclogging the passageway); Se-Shim-Tang-Ga-Mi for removing the stagnancy of the liver and resolving the phlegm; and the like. 5. The research papers on, the medication cases of Alzheimer-type dementia understand the pathology of Alzheimer-type dementia from a consistent perspective. They view the pathology of Alzheimer-type dementia as the disease of Bon-Heo-Pyo-Shil(state of deficient vital essence and excessive pestilential vapor) with the combination of the deficiency of essence of the kidney, the deficiency of the brain marrow, blood stasis and blocked phlegm and the like and recommend the prescription of using Bo and Sa simultaneously for treating Alzheimer-type dementia. 6. The research papers on the medication cases of Alzheimer-type dementia reported that the use of creative prescriptions such as Si-Sam-Hang-Ji-Tang, Ji-Yung-Tang, Ka-Mi-Yunh-Ji-Hwan, Ja-Sin-Hwal-Hyel-Tang, Kal-Chang-Ik-Ji-Tang, Ho-Su-Bok-Ji-Tang, Kun-Noe-Ok-Ji-Hap-Je and the like led to the average high efficacy of 85.5%.

• Journal of Korean Society of Forest Science
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• v.103 no.1
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• pp.129-136
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• 2014

This study aims to investigate the effect of frequency of using forest environment on workers' stress. Workers in medical and counseling industry, which is recently known to require heavy emotional burden and thus cause a lot of stress and burnout syndrome, participated in the study. We classified 370 subjects, who were working at medical and counseling service institutions in Seoul metropolitan area, into two groups according to frequency of using forest environment by conducting a screening survey. 69 subjects submitted written consent and were recruited for either forest therapy program or control-group test; the "high" group (n=27) at the high frequency of using forest environment and the "low" group (n=42) at the low level. We measured the level of stress by using psychosocial indicators such as Worker's Stress Response Inventory (WSRI), Recovery Experience Questionnaire (REQ), and Maslach Burnout Inventory-General Survey (MBI-GS) and biological ones such as heart rate variability (HRV), cortisol, and Natural Killer cell (NK cell). The results suggested that the level of stress differed by frequency. The "high" group showed significantly low scores in the depression and work sub-scale and the total score of WSRI, emotional exhaustion, professional efficacy and total score of MBI-GS, and high scores in the total score of REQ. Similar tendencies were observed in the most of other indicators of psychosocial measures. Regarding the biological indicators, the "high" group showed the highest SDNN, RMSSD and TP measures of HRV and NK Cell activity and the low cortisol, although the statistical power did not reach the significant level. Our results suggest that the subjects who use forest environment frequently show favorable stress level both psychologically and biologically.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.4
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• pp.153-178
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• 2018

Most operational uses of wind speed data require measurements at, or estimates generated for, the reference height of 10 m above mean sea level (AMSL). On the Ieodo Ocean Research Station (IORS), wind speed is measured by instruments installed on the lighthouse tower of the roof deck at 42.3 m AMSL. This preliminary study indicates how these data can best be converted into synthetic 10 m wind speed data for operational uses via the Korea Hydrographic and Oceanographic Agency (KHOA) website. We tested three well-known conventional empirical neutral wind profile formulas (a power law (PL); a drag coefficient based logarithmic law (DCLL); and a roughness height based logarithmic law (RHLL)), and compared their results to those generated using a well-known, highly tested and validated logarithmic model (LMS) with a stability function (${\psi}_{\nu}$), to assess the potential use of each method for accurately synthesizing reference level wind speeds. From these experiments, we conclude that the reliable LMS technique and the RHLL technique are both useful for generating reference wind speed data from IORS observations, since these methods produced very similar results: comparisons between the RHLL and the LMS results showed relatively small bias values ($-0.001m\;s^{-1}$) and Root Mean Square Deviations (RMSD, $0.122m\;s^{-1}$). We also compared the synthetic wind speed data generated using each of the four neutral wind profile formulas under examination with Advanced SCATterometer (ASCAT) data. Comparisons revealed that the 'LMS without ${\psi}_{\nu}^{\prime}$ produced the best results, with only $0.191m\;s^{-1}$ of bias and $1.111m\;s^{-1}$ of RMSD. As well as comparing these four different approaches, we also explored potential refinements that could be applied within or through each approach. Firstly, we tested the effect of tidal variations in sea level height on wind speed calculations, through comparison of results generated with and without the adjustment of sea level heights for tidal effects. Tidal adjustment of the sea levels used in reference wind speed calculations resulted in remarkably small bias (<$0.0001m\;s^{-1}$) and RMSD (<$0.012m\;s^{-1}$) values when compared to calculations performed without adjustment, indicating that this tidal effect can be ignored for the purposes of IORS reference wind speed estimates. We also estimated surface roughness heights ($z_0$) based on RHLL and LMS calculations in order to explore the best parameterization of this factor, with results leading to our recommendation of a new $z_0$ parameterization derived from observed wind speed data. Lastly, we suggest the necessity of including a suitable, experimentally derived, surface drag coefficient and $z_0$ formulas within conventional wind profile formulas for situations characterized by strong wind (${\geq}33m\;s^{-1}$) conditions, since without this inclusion the wind adjustment approaches used in this study are only optimal for wind speeds ${\leq}25m\;s^{-1}$.