• Communications for Statistical Applications and Methods
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• v.30 no.2
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• pp.119-133
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• 2023

With the rapid growth of the economy and fossil fuel consumption, the concentration of air pollutants has increased significantly and the air pollution problem is no longer limited to small areas. We conduct statistical analysis with the actual data related to air quality that covers the entire of South Korea using R and Python. Some factors such as SO₂, CO, O₃, NO₂, PM₁₀, precipitation, wind speed, wind direction, vapor pressure, local pressure, sea level pressure, temperature, humidity, and others are used as covariates. The main goal of this paper is to predict air quality index (AQI) spatio-temporal data. The observations of spatio-temporal big datasets like AQI data are correlated both spatially and temporally, and computation of the prediction or forecasting with dependence structure is often infeasible. As such, the likelihood function based on the spatio-temporal model may be complicated and some special modelings are useful for statistically reliable predictions. In this paper, we propose several methods for this big spatio-temporal AQI data. First, random effects with spatio-temporal basis functions model, a classical statistical analysis, is proposed. Next, neural networks model, a deep learning method based on artificial neural networks, is applied. Finally, random forest model, a machine learning method that is closer to computational science, will be introduced. Then we compare the forecasting performance of each other in terms of predictive diagnostics. As a result of the analysis, all three methods predicted the normal level of PM_2.5 well, but the performance seems to be poor at the extreme value.

• Animal Bioscience
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• v.37 no.1
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• pp.16-27
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• 2024

Objective: The objective of this study was to investigate the effect of heat stress on the growth traits and genetic parameters of Thai native chickens. Methods: A total of 16,487 records for growth traits of Thai native chickens between 2017 and 2022 were used in this study. Data included the body weight at birth, body weight at 4, 8, and 12 weeks of age (BW0, BW4, BW8, BW12), average daily gain during 0 to 4, 4 to 8, and 8 to 12 weeks of age (ADG0-4, ADG4-8, ADG8-12), absolute growth rate at birth, at 4, 8, and 12 weeks of age (AGR0, AGR4, AGR8, AGR12). The repeatability test day model used the reaction-norm procedure to analyze the threshold point of heat stress, rate of decline of growth traits, and genetic parameters. Results: At temperature and humidity index (THI) of 76, Thai native chickens began to lose their growth traits, which was the onset of heat stress in this study. The estimated heritability, genetic correlation between animal and heat stress effect, and correlations between the intercept and slope of the permanent environmental effects were 0.27, -0.85, and -0.83 for BW, 0.17, -0.81, and -0.95 for ADG, 0.25, -0.61, and -0.83 for AGR, respectively. Male chickens are more affected by heat stress than female chickens with a greater reduction of BW, ADG, and AGR, values equal to -9.30, -0.23, -15.21 (in males) and -6.04, -0.21, -10.10 (in females) gram per 1 level increase of THI from the THI of 76. Conclusion: The influence of thermal stress had a strong effect on the decline in growth traits and genetic parameters in Thai native chickens. This study indicated that genetic models used in conjunction with THI data are an effective method for the analysis and assessment of the effects of heat stress on the growth traits and genetics of native chickens.

• Fashion & Textile Research Journal
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• v.26 no.1
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• pp.123-136
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• 2024

This study aimed to assess the mobility and thermal comfort of personal protective equipment (PPE) among female healthcare workers, taking into account wearers' physique and PPE protection levels. A total of 16 participants (age: 26.3 ± 8.3 y, height: 161.5 ± 7.3 cm, body weight: 57.1 ± 11.0 kg, BMI: 21.9 ± 3.6), representing diverse body types, underwent four PPE conditions: L (Low_Plastic gown ensemble), M (Medium_Tyvek 400), H (High_Tyvek 800J with Powered Air Purifying Respirator [PAPR]), and E (Extremely high_Tychem 2000 with PAPR, Bib apron, and Chemical-resistant gloves). The mobility protocol consisted of 10 different tasks in addition to donning and doffing. The 10 tasks were repeated twice at an air temperature of 24.3 ± 0.1℃, 59±4%RH. Findings revealed a disproportionate relationship between PPE protection and wearer discomfort. Significant differences in clothing microclimate and total sweat rate were observed between the lowest (L) and highest (E) protection levels (p < 0.01), while distinctions among medium levels were inconclusive. Subjective evaluations favored conditions H and L over M and E (p < 0.05), indicating reduced heat, and humidity, increased comfort, and lower exertion. Instances of mobility discomfort, specially in the small body type group, underscored the need for a suitable PPE size system for Korean adult female medical workers. Furthermore, enhancements in gloves, shoe cover, and PAPR hood designs are essential for improving ease of movement and preventing hindrance.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.389-396
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• 2014

Purpose: The study examined dry eye symptoms of occupants in a newly constructed building and its effects on their work productivity and general activity. Methods: The study subjects were 33 office workers who spent more than eight hours per day on average in a new building constructed in the past three months. The indoor air quality of the new building was evaluated by measuring aldehydes, temperature and humidity. The level of dry eye symptoms was classified into normal, mild, moderate and severe by using the Ocular Surface Disease Index (OSDI). The experience of LASIK surgery, use of eye makeup, daily use time of a computer and smart-phone, and average daily working hours were also examined. The Work Limitation Productivity Questionnaire was used as the questionnaire about work productivity and general activity to measure the impairment level on a ten-point scale. Results: The concentration variation of formaldehyde in the office was $42.42{\pm}6.30{\mu}g/m^3$. The temperature and humidity were $26.2{\pm}0.70^{\circ}C$ and $40{\pm}1%$, respectively. The respondents with normal, mild, moderate and severe dry eye symptoms were 15.2%, 18.2%, 18.2% and 48.5%, respectively. The severity of dry eye symptoms and impairment of work productivity and general activity demonstrated high correlations of 0.599 and 0.655, respectively (p<0.001). Compared to the normal case, severe dry eye symptoms demonstrated significantly high impairment of work productivity and interruption of general activity (p<0.001). The case of serious dry symptoms showed the possibilities of having impairment level of work productivity and interruption of general activity above three points 3.26 times (p=0.032) and 2.25 times (p=0.045), respectively, higher than that of the normal case. Conclusions: It was confirmed that dry eye symptoms among office workers in a newly constructed building affects work productivity and general activity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s02
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• pp.13-33
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• 1989

Agroclimate should be analyzed and evaluated accurately to make better use of available chimatic resources for the establishment of optimum cropping systems. Introducing of appropriate cultivars and their cultivation techniques into classified agroclimatic zone could contribute to the stability and costs of crop production. To classify the agroclimatic zones, such climatic factors as temperature, precipitation, sunshine, humidity and wind were considered as major influencing factors on the crop growth and yield. For the classification of rice agroclimatic zones, precipitation and drought index during transplanting time, the first occurrence of effective growth temperature (above 15$^{\circ}C$) and its duration, the probability of low temperature occurrence, variation in temperature and sunshine hours, and climatic productivity index were used in the analysis. The agroclimatic zones for rice crop were classified into 19 zones as follows; (1) Taebaek Alpine Zone, (2) Taebaek Semi-Alpine Zone, (3) Sobaek Mountainous Zone, (4) Noryeong Sobaek Mountainous Zone, (5) Yeongnam Inland Mountainous Zone, (6) Northern Central Inland Zone, (7) Central Inland Zone, (8) Western Soebaek Inland Zone, (9) Noryeong Eastern and Western Inland Zone, (10) Honam Inland Zone, (ll) Yeongnam Basin Zone, (12) Yeongnam Inland Zone, (13) Western Central Plain Zone, (14) Southern Charyeong Plain Zone, (15) South Western Coastal Zone, (16) Southern Coastal Zone, (17) Northern Eastern Coastal Zone, (18) Central Eastern Coastal Zone, and (19) South Eastern Coastal Zone. The classification of agroclimatic zones for cropping systems was based on the rice agroclimatic zones considering zonal climatic factors for both summer and winter crops and traditional cropping systems. The agroclimatic zones were identified for cropping systems as follows: (I) Alpine Zone, (II) Mountainous Zone, (III) Central Northern Inland Zone, (IV) Central Northern West Coastal Zone, (V) Cental Southern West Coastal Zone, (VI) Gyeongbuk Inland Zone, (VII) Southern Inland Zone, (VIII) Southern Coastal Zone, and (IX) Eastern Coastal Zone. The agroclimatic zonal characteristics of climatic disasters under rice cultivation were identified: as frequent drought zones of (11) Yeongnam Basin Zone, (17) North Eastern Coastal Zone with the frequency of low temperature occurrence below 13$^{\circ}C$ at root setting stage above 9.1％, and (2) Taebaek Semi-Alpine Zone with cold injury during reproductive stages, as the thphoon and intensive precipitation zones of (10) Hanam Inland Zone, (15) Southern West Coastal Zone, (16) Southern Coastal Zone with more than 4 times of damage in a year and with typhoon path and heavy precipitation intensity concerned. Especially the three east coastal zones, (17), (18), and (19), were subjected to wind and flood damages 2 to 3 times a year as well as subjected to drought and cold temperature injury.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.8
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• pp.1188-1193
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• 2005

An investigation was carried out to study the effect of two housing systems on physiological responses and energy expenditure of sheep in a semi-arid region of India. Two types of housing management were adopted. First was a shed- $6{\times}3\;m^2$ structure with all the four sides of 1.8 m chain link fencing with a central height of 3 m. The roof was covered with asbestos sheets and with mud floorings. Second was an open corral- $6{\times}3\;m^2$ open space with all the four sides covered with 1.8 m chain link fencing. Thirty-four (32 ewes and 2 rams) sheep of native Malpura breed aged about 18 months (body weight 28 kg ewes; 35 kg rams) were grazed together on a 35 ha plot of native range. All the sheep were grazed as a flock from 08.00 to 17.00 h during a yearlong study. The flock was divided into two groups (16 ewes+1 ram) in the evening and housed as per the systems (Shed and Open Corral). Dry and wet temperatures were recorded at 06.00 h and 21.00 h using a wet and dry bulb-thermometer both inside the shed and in the open corral and temperature humidity index (THI) was calculated. There was significant (p<0.05) difference in the THI between shed and open corral in all the seasons, indicating that shed was always warmer compared to open corral. Rectal temperature (RT) of both the groups of sheep was similar during morning as well as evening throughout the seasons. There were significant (p<0.05) differences in the skin temperature (ST) and respiration rate (RR) between the two groups at both the measurements in all the seasons. Highest energy expenditure (EE) was recorded inside the shed at 21.00 h (224 kJ/h) during monsoon and lowest at 6.00 h during winter (119 kJ/h). There was a significant (p<0.05) difference between the EE inside the shed and that in the open corral. It was concluded that housing had significant effects on the physiological responses and EE of sheep. Provision of housing at night was stressful during monsoon (with less rainfall) and summer, whereas it was protecting the sheep from acute cold during winter in a semi-arid region of India.

• Clean Technology
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• v.25 no.1
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• pp.33-39
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• 2019

A.C (activated carbon) is mainly used to remove VOCs (volatile organic compounds), however, it has many problems such as fire risk due to increasing of adsorbent surface temperature during VOCs ad/desorption, increased cost by frequent replacement cycles requirement and performance degradation when containing moisture. In order to solve these problems, many researches, hydrophobic zeolite adsorbents, have been reported. In this study, $NH_4{^+}Y$-zeolite was synthesized with Y-zeolite through steam treatment and acid treatment, which is one of the hydrophobic modification methods, to secure high surface area, thermal stability and humidity resistance. The Y, Y-550-HN, Y-600-HN and Y-650-HN had adsorption capacities of $23mg\;g^{-1}$, $38mg\;g^{-1}$, $77mg\;g^{-1}$, $61mg\;g^{-1}$. The change of Si/Al ratio, which is an index to confirm the degree of modification, was confirmed by XRF (X-ray fluorescence spectrometer) analysis. As a result, the adsorbtion performance was improved when Y-zeolite modified, and the Si/Al ratio of Y, Y-550-HN, Y-600-HN, Y-650-HN were increased to 3.1765, 6.6706, 7.3079, and 7.4635, respectively. Whereas it was confirmed that structural crystallization due to high heat treatment temperature affected performance degradation. Therefore, there is an optimal heat treatment temperature of Y-zeolite, optimum modification condition study could be a substitute for activated carbon as a condition for producing an adsorbent having high durability and stability.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.826-833
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• 2019

Objective: This study was performed to evaluate whether hot temperature and rumen-protected fat (RPF) supplementation affect growth performance, rumen characteristics, and serum metabolites in growing stage of Korean cattle steers. Methods: Twenty Korean cattle steers ($230.4{\pm}4.09kg$ of body weight [BW], $10.7{\pm}0.09months$ of age) were divided into a conventional control diet group (n = 10) and a 0.8% RPF supplementation group (n = 10). Steers were fed 1.5% BW of a concentrate diet and 4 kg of tall fescue hay for 16 weeks (July 10 to August 6 [P1], August 7 to September 3 [P2], September 4 to October 1 [P3], October 2 to 30 [P4], of 2015). Results: The mean temperature-humidity index (THI) was higher (p<0.001) in P1 (76.8), P2 (76.3), and P3 (75.9) than in P4 (50.9). The mean THI of P1-3 were within the alert heat stress (HS) category range according to previously reported categories for feedlot cattle, and the mean THI of P4 was under the thermo-neutral range. Neither month nor RPF supplementation affected (p>0.05) average daily gain and gain to feed ratio. Month and RPF supplementation affected concentrations of glucose, albumin, and high-density lipoprotein (HDL); those of albumin and glucose tended to decrease (p<0.10), but HDL concentration increased (p<0.01) by RPF supplementation. Neither month nor RPF affected (p>0.05) ruminal pH, $NH_3-N$, and volatile fatty acid concentrations, whereas the C2:C3 ratio was affected (p<0.05) by month. Conclusion: Korean cattle may not have been significantly affected by alert HS during the growing stage. Growth performance was higher during hotter months, although some changes in blood metabolites were observed. The RPF supplementation affected some blood lipids and carbohydrate metabolites but did not affect growth performance.

• Journal of the Korean earth science society
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• v.37 no.7
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• pp.420-433
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• 2016

The purpose of this study is to improve the calibration matrixes of 2-D and 3-D convective rainfall rates (CRR) using the brightness temperature of the infrared $10.8{\mu}m$ channel (IR), the difference of brightness temperatures between infrared $10.8{\mu}m$ and vapor $6.7{\mu}m$ channels (IR-WV), and the normalized reflectance of the visible channel (VIS) from the COMS satellite and rainfall rate from the weather radar for the period of 75 rainy days from April 22, 2011 to October 22, 2011 in Korea. Especially, the rainfall rate data of the weather radar are used to validate the new 2-D and 3-DCRR calibration matrixes suitable for the Korean peninsula for the period of 24 rainy days in 2011. The 2D and 3D calibration matrixes provide the basic and maximum CRR values ($mm\;h^{-1}$) by multiplying the rain probability matrix, which is calculated by using the number of rainy and no-rainy pixels with associated 2-D (IR, IR-WV) and 3-D (IR, IR-WV, VIS) matrixes, by the mean and maximum rainfall rate matrixes, respectively, which is calculated by dividing the accumulated rainfall rate by the number of rainy pixels and by the product of the maximum rain rate for the calibration period by the number of rain occurrences. Finally, new 2-D and 3-D CRR calibration matrixes are obtained experimentally from the regression analysis of both basic and maximum rainfall rate matrixes. As a result, an area of rainfall rate more than 10 mm/h is magnified in the new ones as well as CRR is shown in lower class ranges in matrixes between IR brightness temperature and IR-WV brightness temperature difference than the existing ones. Accuracy and categorical statistics are computed for the data of CRR events occurred during the given period. The mean error (ME), mean absolute error (MAE), and root mean squire error (RMSE) in new 2-D and 3-D CRR calibrations led to smaller than in the existing ones, where false alarm ratio had decreased, probability of detection had increased a bit, and critical success index scores had improved. To take into account the strong rainfall rate in the weather events such as thunderstorms and typhoon, a moisture correction factor is corrected. This factor is defined as the product of the total precipitable waterby the relative humidity (PW RH), a mean value between surface and 500 hPa level, obtained from a numerical model or the COMS retrieval data. In this study, when the IR cloud top brightness temperature is lower than 210 K and the relative humidity is greater than 40%, the moisture correction factor is empirically scaled from 1.0 to 2.0 basing on PW RH values. Consequently, in applying to this factor in new 2D and 2D CRR calibrations, the ME, MAE, and RMSE are smaller than the new ones.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.130-139
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• 2017

This study investigated the effect of heat stress on the performance and blood characteristics in commercial pig farms. A total of 180 growing pigs and 180 finishing pigs were assigned to two treatments consisting of thermal-neutral period(TNP) and high-temperature period(HTP) with three replications in floor pen, respectively. Feeding trials in the TNP and HTP were individually performed in autumn and summer seasons, respectively. Temperature-humidity index(THI) was calculated by temperature and humidity. Performance and physiological responses were identified per growth stages and feeding trial. Average temperature and THI were $16.8^{\circ}C$ and 61.4 at the TNP, and $25^{\circ}C$ and 74.3 at the HTP, respectively. Growing pigs in HTP exhibited lower BW, ADG and ADFI than in TNP(p<0.01). Similarly, finishing pigs showed lower growth parameters in HTP than in TNP(p<0.01). Lymphocytes and neutrophils of growing pigs were lower in HTP than in TNP(p<0.05). The serum T-PRO and NEFA in finishing pigs were higher in HTP than in TNP(p<0.05). In HTP, finishing pigs had higher cortisol levels than in TNP. Therefore, HTP can negatively influence growth performance and nutritional metabolism in pigs. Our results may provide useful information for developing feeding programs and diets to control heat stress for swine farms.