• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1700-1710
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• 1992

The boundary element method is applied to determine thermal stress intensity factors for a cusp crack in transient state. In the steady temperature field, numerical values of thermal stress intensity factors for a Grifith crack and a symmetric lip cusp crack in a finite body are in good agreement within .+-. 5% with the previous solutions. In transient state, the numerical values of thermal stress intensity factors for the Griffith crack are also in good agreement with the pervious solutions. In both steady and transient states, those for the symmetric lip cusp crack with the crack surface insulated or fixed to the constant temperature are calculates for various effective crack lengths, configuration parameters and uniform heat flow angles. The variations of the thermal boundary conditions of the crack surface have a effect on stress intensity factors. The signs on the values of thermal stress intensity factors can be changed in time variation.

• Korean Journal of Organic Agriculture
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• v.27 no.2
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• pp.161-171
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• 2019

A light-emitting diode (LED) is most efficient in terms of economic benefits. The aim of the present study was to evaluate the effects of LED lighting intensity on milk production, milk composition, and the immune response of Holstein cows. Thirty-eight lactating cows were assigned to four experimental groups: control group (exposed natural daylight without LED light) and three LED treatment group (50 lux; natural daylight and 6 h LED light of 50 lux intensity, 100 lux; natural daylight and 6 h LED light of 100 lux intensity, 200 lux; natural daylight and 6 h LED light of 200 lux intensity). There was a significant effect on the decrease ratio in milk production in 200 lux group. Lactose was significantly increased in 100 lux than the other LED treated groups. In addition to the hemolytic biochemical analysis, AST and β-HB were significantly increased in the 50 lux than the other groups. Prolactin and IGF-1 levels were significantly increased in 200 lux compared to other groups. Besides, cortisol was significantly higher in 50 lux and lowered in the 200 lux than the control, while IgA and IgG were not significant among the groups. Therefore, it was concluded that LED lighting intensity had some impact on blood parameters and immune responses in dairy cows with increased milk production.

• Atmosphere
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• v.26 no.1
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• pp.1-18
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• 2016

Eleven Tropical Cyclone (TC) intensity guidance models in the western North Pacific have been validated over 2008~2014 based on various analysis methods according to the lead time of forecast, year, month, intensity, rapid intensity change, track, and geographical area with an additional focus on TCs that influenced the Korean peninsula. From the evaluation using mean absolute error and correlation coefficients for maximum wind speed forecasts up to 72 h, we found that the Hurricane Weather Research and Forecasting model (HWRF) outperforms all others overall although the Global Forecast System (GFS), the Typhoon Ensemble Prediction System of Japan Meteorological Agency (TEPS), and the Korean version of Weather and Weather Research and Forecasting model (KWRF) also shows a good performance in some lead times of forecast. In particular, HWRF shows the highest performance in predicting the intensity of strong TCs above Category 3, which may be attributed to its highest spatial resolution (~3 km). The Navy Operational Global Prediction Model (NOGAPS) and GFS were the most improved model during 2008~2014. For initial intensity error, two Japanese models, Japan Meteorological Agency Global Spectral Model (JGSM) and TEPS, had the smallest error. In track forecast, the European Centre for Medium-Range Weather Forecasts (ECMWF) and recent GFS model outperformed others. The present results has significant implications for providing basic information for operational forecasters as well as developing ensemble or consensus prediction systems.

• Journal of the Korean GEO-environmental Society
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• v.11 no.2
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• pp.13-21
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• 2010

The unsaturated slope usually is stable for a long time, but fails during heavy rainfall. And the factors of the rainfall intensity exhibit significant roles because the water content and the shear stress developed along the potential failure surface will be changed by the rainfall intensity. The objective of the study presented in this paper is to analyze the relationship between rainfall intensity and shear stress of the soil slopes by applying the laboratory slope model apparatus and undrained direct shear test with rainfall intensity controlled. The soil sample was taken from the field slope of Youngdong, and particle size analysis was done. To look over the relationship between rainfall intensity and shear strength of slope, the three-dimensional relationships among shear strength, normal stress and water content of the slope soil samples are examined; those are based on the data from the TDR sensor and undrained direct shear test.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.6
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• pp.1122-1130
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• 2001

Recently the importance of distribution channel design has been focused on due to a turbulent environment. The channel design strategy involves the choice of an optimal channel arrangement including channel width, channel depth, the types of intermediaries to be used, and the specific responsibilities of each channel member. The purpose of this paper is to investigate changes of distribution intensity in the infant & children's wear brand from 1997 to 1999, when Korea has faced changes before and after IMF intervention that influenced the Korean economy greatly. Thus, this study provides channel managers with some guidelines for establishing and adjusting the infant & children's wear channel strategies. The data is collected by the Korean Fashion Brand Annual published by Apparel News Co., from 1997 to 1999. infant & children's wear brands are selected and analyzed with Pearson correlation. Statistic analysis has shown different results in the type of brands in terms of distribution intensity. The type of brands between infant's wear and those for children differ in price and launching period. In the case of infant's wear brands, the launching period and total sales should be considered in designing channel distributions, while for children's brands total sales are significant. As the price increases, children's wear brands are significantly linked to their distribution intensity only in certain times at the starting point of IMF intervention. IMF intervention do not seem to influence the distribution intensity of infant's wear brands much as it did children's wear brands. It seems that the infant's wear industry is more stable than the children s wear industry. As a result, the marketer who plans distribution intensity for the infant's and children's wear brands should consider total sales, the launching period and the price according to the type of brands he deals with.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.2
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• pp.193-200
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• 2014

PURPOSE: This study examined the effects of treadmill exercise of diverse intensities on the expression of IL-$1{\beta}$ (interleukine-$1{\beta}$) in the spinal cord in osteoarthritis rats. METHODS: The authors applied treadmill exercise of diverse intensity for 4 weeks to Sprague-Dawley rats to which intra-articular injection of monosodium iodoacetate(MIA, $3mg/50{\mu}l$, diluted in saline) was applied in the right knee joint to induce osteoarthritis. The four-week exercise was not applied to the control group(CG, n=15), while exercise of applicable intensity was applied to the low-intensity exercise group(LEG, n=15), moderate-intensity exercise group (MEG, n=15), and high-intensity exercise group(HEG, n=15) for four weeks. Observations were made of expression of IL-$1{\beta}$ in the spinal cord in osteoarthritis rats using western blot analysis. RESULTS: There were significant differences(p<.05) in the comparison of expression of IL-$1{\beta}$ in the spinal cord between the four groups involved. And the LEG and MEG had reduced expression of IL-$1{\beta}$ significantly than the CG(p<.05); in particular, the MEG showed the lowest expression. On the other hand, the HEG had more elevated expression of IL-$1{\beta}$ significantly than the CG(p<.05). CONCLUSION: As a result, factors that induce neuropathic pain such as IL-$1{\beta}$ are reduced; thus, the recovery of damaged neurons is improved and neuropathic pain is reduced. Further, when prescribing exercise to treat osteoarthritis patients, exercise of moderate intensity suitable for patients' physical conditions, rather than high intensity, maximizes the effects of this therapy.

• Journal of Preventive Medicine and Public Health
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• v.54 no.1
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• pp.46-54
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• 2021

Objectives: This study explored the relationship between shift intensity and insomnia among hospital nurses. Methods: The participants were 386 female hospital nurses who underwent a special health examination for night workers in 2015. The Korean Insomnia Severity Index (ISI), indices of shift work intensity, and other covariates such as amount of exercise, level of alcohol consumption, employment duration, and hours worked were extracted from the health examination data. The indices for shift intensity were (1) number of 3 consecutive night shifts and (2) number of short recovery periods after a previous shift, both assessed over the prior 3 months. Multiple logistic regression analysis adjusted for the aforementioned covariates was performed to evaluate the association of shift intensity with insomnia, defined as an ISI score of ≥8. Results: The nurses with insomnia tended to be younger (p=0.029), to have worked 3 consecutive night shifts more frequently (p<0.001), to have experienced a greater number of short recovery periods after the previous shift (p=0.021), and to have worked for more hours (p=0.006) than the nurses without insomnia. Among the other variables, no statistically significant differences between groups were observed. Experiences of 3 or more consecutive night shifts (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.29 to 4.20) and 3 or more short recovery periods (OR, 2.01; 95% CI, 1.08 to 3.73) were associated with increased odds of insomnia. Conclusions: The results suggest that decreasing the shift intensity may reduce insomnia among hospital nurses working rotating shifts.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.556-563
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• 2010

The main noise source of the rotary compressor for air conditioner was analyzed by using the measurement of sound intensity, modal analysis and operational deflection shape(ODS) analysis. In this study, the key noise source of rotary compressor was an accumulator, and noise was sharply increased due to the accumulator's resonance which has a big contribution to the noise. To reduce the excessive noise generated from accumulator, structural modification through ODS analysis were applied. Its validation was conducted by the measurement of noise and vibration on the accumulator's surface. The total noise was significantly reduced by 4.2dB(A).

• Journal of KSNVE
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• v.8 no.4
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• pp.706-714
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• 1998

The purpose of this study is to analyse the main factors and attributes of psychological evaluation to noise. For this purpose, a psycho-acustic experiment was conducted by using the method of rating scale. 52 subjects were participated in the experiment, 20 stimuli were presented to subjects in random order with 23 adjectives. As a result of factor analysis, it was found that the primary factors for evaluating the quality of noise subjectively are four factors of unpleasantness, intensity, irregularity, and sharpness. And, as a result of MDPREF(multi-dimensional analysis of preference data), it was found that the noise sources including the factors of unpleasantness, intensity, and irregularity are related to the sounds of hammering in construction field, car horn, road traffic, idling of car, and printing by computer printer, and the factor of sharpness are the sounds of car siren, claps of thunder, car horn, and snowstorm etc.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.317-318
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• 2006

A transfer loading system for 21' RF band assembly box was developed in the present study. The weight of a box is approximately 60kgf End total weight of one day job per person is about $4,000kg_f$. For an efficient design and manufacturing process, three dimensional design and engineering technique were applied to the presented system. Motion analysis for a popup unit and structural analysis for belt part subjected to the load of box weight were performed, respectively. It was found that the evasion of duty and labor intensity is reduced after appling the developed system to manufacturing field of small and midium business.