• Korean Journal of Social Welfare Studies
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• v.48 no.2
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• pp.143-171
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• 2017

Along with the well-established evidence on the negative effect of social isolation on physical mental health and mortality, increasing attention has been paid to multi-dimensional nature of social isolation. In this study, the main effect and interaction effect of objective and subjective social isolation on heterogeneous age cohort related to the onset of dementia, which is becoming a social problem due to rapid aging of health issues, was examined through binary logistic regression analysis. Data came from the first wave of Korean Social Life, Health and Aging Project (KSHAP) (N= 814). Findings showed 1) in the young-old, objective isolation was a significant on the incidence of dementia, 2) in the old-old, subjective isolation increased the risk of dementia. In summary, the relative influence of objective and subjective social isolation related to the incidence of dementia varies depending on the young-old and old-old. On the other hand, the interaction effect of objective and subjective social isolation on dementia was not significant in both the young-old and old-old. Based on the findings, we discussed implications and suggestions for future research and relevant policy and program development(dementia-friendly communities) for ameliorating objective and subjective social isolation.

• Korean Journal of Construction Engineering and Management
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• v.22 no.2
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• pp.31-41
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• 2021

The purpose of this study is to analyze the properties of previous studies related to vocations in the construction field. The results of the analysis are as follows. First, The paper has not been published at the beginning of the establishment of the academic foundation for vocational studies, but there was a marked increase over the next 15 years. Second, research related to vocations in the construction field has been more active in engineering than in social science. Third, the primary data method was used much more than the secondary data method, and the quantitative research method through a questionnaire was the most common research method. Fourth, human objects showed the highest frequency as 78.9%, and among them, technicians was the most. Fifth, as the research topic, psychological and behavioral aspects such as job satisfaction, job stress, turnover intention, and organizational commitment were dealt with most, and structural and environmental aspects such as national job competency standards, job analysis, construction accidents, and career development. It was also found that the topic of the research was actively being dealt with.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.193-199
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• 2021

Solenopsis japonica, which is belonging to Formicidae in Hymenoptera, is a native ant species in Korea. However, it had not been studied for cold hardiness of S. japonica to understand on its overwintering mechanisms in field so far. Cold tolerance on developmental stages was measured at different cold temperature with various exposure times. Workers showed more survival at 5℃ and 10℃ compared with other stages and elevated cold tolerance when workers were exposed at 15℃ for more than 12h incubation as a rapid cold hardening (RCH) condition. RCH treatment not only increased survival of workers at cold temperatures, but also decreased supercooling point (SCP) and freezing point (FP). RCH group increased the survival rate by 44% at 10℃ compared with Non-RCH group. SCP and FP were depressed from -10.0 to -14.2℃ and from -11.3 to -15.3℃, respectively, after RCH treatment. Cold temperature increased expression level of cold- and stress-related genes such as glycerol kinase and heat shock protein. These results indicate unacclimated cold tolerance of S. japonica and its acclimation to low temperature by RCH.

• Ecology and Resilient Infrastructure
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• v.10 no.1
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• pp.11-19
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• 2023

Alien species are known to threaten regional biodiversity globally, which has increased global interest regarding introduction of alien species. The Ministry of Environment of Korea designated species that have not yet been introduced into the country with potential threat as alert alien species to prevent damage to the ecosystem. In this study, potential habitats of Esox lucius and Maccullochella peelii, which are predatory and designated as alert alien fish, were predicted on a national basis. Habitat suitability was evaluated using EHSM (Ecological Habitat Suitability Model), and water temperature data were input to calculate Physiological Habitat Suitability (PHS). The prediction results have shown that PHS of the two fishes were mainly controlled by heat or cold stress, which resulted in biased habitat distribution. E. lucius was predicted to prefer the basins at high latitudes (Han and Geum River), while M. peelii preferred metropolitan areas. Through these differences, it was expected that the invasion pattern of each alien fish can be different due to thermal preference. Further studies are required to enhance the model's predictive power, and future predictions under climate change scenarios are required to aid establishing sustainable management plans.

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.459-468
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• 2004

An experiment was conducted to establish comparison of ventulation efficiency in an enclosed and conventional growing-finishing pig house. The main results of the experiment are as follows : In the established temperature was sustained at the level of summer 24.8${\sim}$29.1$^{\circ}C$, winter 17.9${\sim}$23.1$^{\circ}C$ during the experimental period of enclosed growing-finishing pig house, and conventional growing-finishing pig house was at the lovel of summer 24.7${\sim}$32.3$^{\circ}C$, winter 14.5${\sim}$18.2$^{\circ}C$ during the experimental period respectively. As for the results of dertimental gas(ammonia) concentration ratio analysis, while the conventional pig house sustained of summer 9.3${\sim}$16.9 mg/$\ell$ level, enclosed growing-finishing pig house sustained of summer 7.9${\sim}$16.1 mg/$\ell$, and the latter one is lower than that of the conventional growing-finishing pig house. Air flow rate on the floor level which is the low part of pen and the active area of pigs in the enclosed growing and finishing pig house during winter was measured at 0 to 0.87 m/s at the 0.01 to 2.73 m/s at the maximum ventilation efficiency. As for breeding pigs in summer, the pigs from the conventional pig house weighed 100.2kg, on the other hand, the pigs from enclosed growing-finishing pig house weighed 107.3 kg ; the differnce between the two kinds was about 7 kg. This was because the most adequate environment, which was not influenced by the exterior atmosphere, was offered to the pigs from enclosed growing-finishing pig house, and all of this could reduce pigs stress effectively.

• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.13-27
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• 2015

A systemic review on the factors affecting food catering hygiene was conducted to provide information for risk management of food catering in Korea. In total 47 keywords relating to food catering and food hygiene were searched for published journals in the DBpia for the last decade (2005-2014). As a result, 1,178 published papers were searched and 142 articles were collected by the expert review. To find the major factors affecting food catering and microbial safety, an analysis based on organization and stakeholder were conducted. School catering (64 papers) was a major target rather than industry (5 pagers) or hospitals (3 papers) in the selected articles. The factors affecting school catering were "system/facility/equipment (15 papers)", "hygiene education (12 papers)", "production/delivery company (6 papers)", food materials (4 papers)" and "any combination of the above factors (9 papers)". The major problems are follow. 1) The problems of "system/facility/equipment" were improper space division/separation, lack of mass cooking utensil, lack of hygiene control equipment, difficulty in temperature and humidity control, and lack of cooperation in the HACCP team (dietitian's position), poor hygienic classroom in the case of class dining (students'), hard workload/intensity of labor, poor condition of cook's safety (cook's) and lack of parents' monitoring activity (parents'). 2) The problem of "hygiene education' were related to formal and perfunctory hygiene education, lack of HACCP education, lack of compliance of hygiene practice (cook's), lack of personal hygiene education and little effect of education (students'). 3) The problems of "production/delivery company" were related to hygiene of delivery truck and temperature control, hygiene of employee in the supplying company and control of non-accredited HACCP company. 4) The area of "food materials" cited were distrust of safety regarding to raw materials, fresh cut produces, and pre-treated food materials. 5) In addition, job stability/the salary can affect the occupational satisfaction and job commitment. And job stress can affect the performance and the hygiene practice. It is necessary for the government to allocate budget for facility and equipment, conduct field survey, improve hygiene training program and inspection, prepare certification system, improve working condition of employees, and introducing hygiene and layout consulting by experts. The results from this study can be used to prepare education programs and develop technology for improving food catering hygiene and providing information.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.283-290
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• 2017

In this study, the method to attach plastic film on the side vent from inside of greenhouse for the entire length was developed as the way to make crops less stressful while uniformly getting outside air into the greenhouse when ventilating using roof ventilation fans at single-span plastic greenhouse for oriental melon in a low-temperature period. The plastic film was installed from ground to 10cm below from the height where side vent is fully opened. In order to verify that the improved side vent can improve greenhouse environment and fruit yield, it was compared with the control plot of conventional side vent. Both greenhouses were not ventilated until February 25th, 2017. Air temperature in both greenhouses exceeded $40^{\circ}C$ in mid February. Therefore, it is judged that the greenhouse should be ventilated from mid February. Air temperature in the control plot exceeded $30^{\circ}C$ from late April. Therefore, it is judged that the plastic film attached to the inside of side vent should be removed in late April, or in early May at the latest. Soil temperature in the treatment plot in the mid Aril exceeded $20^{\circ}C$, which is suitable for growth, while that in the control plot was still below $20^{\circ}C$. Soil temperature in the control plot finally exceeded $20^{\circ}C$ in late April. The consumption of electricity was 47.2 kWh in the treatment plot, and 48.3 kWh in the control plot, which was no significant difference. The marketable yield of oriental melon in the treatment plot was 5,094kg, which was 23.9% more than that in the control plot, 4,113kg. The marketable fruit ratio was 73.5% in the treatment plot, and that in the control plot was 73.9%, which was no significant difference.

• Journal of Plant Biology
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• v.37 no.3
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• pp.387-394
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• 1994

Effects of environmental factors of light, temperature, nitrogen sources and water stress were analyzed quantitatively on the nodule formation and nitrogen fixation activity of autumn olive plant (Elaeagnu$ umbellala Thunb.) during the seedling growth. Seedlings showed the maximum nitrogenase activity of $72.5\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$ in the early nodulation stage. The relative growth rate and T/R ratio changed from $1.60%{\cdot}d^{-1}$ and 1.12 in the earlier stage to $3.75%{\cdot}d^{-1}$ and 2.31 in the later stage, respectively. light conditions of 20-25, 1015 and 4-6% resulted in decreases of 41, 54 and 71% of the nitrogenase activity, respectively. Nodules incubated in 15, 20, 25 and $30^{\circ}C$ showed the activities of 5.4, 24.7, 51.6 and $58.5\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$ respectively. Pretreatment with low temperature ($15^{\circ}C$) followed incubation at $30^{\circ}C$ attained higher nitrogenase activity ($66.5\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$) than that with higher temperature ($35^{\circ}C$). The oxygen pressure above 16 kPa is necessary for saturation of the nodule activity, but the activity was inhibited severely by physical impact such as the exision or isolation of nodules from the root. The relative activities of early nodules grown in pH 5.5, 6.5 and 8.0 were 89, 100 and 40% and those grown in 1 and 3 mM of $NO_3\;and\;NH_4$ were 6, 1 and 68, 50%, respectively. Watering levels of 20, 50 and 100 mL during the seedling growth resulted in 35, 120 and 8 mg of nodule formation and 33.6, 58.4 and $8.4\;\mu\textrm{M}\;C_2H_4{\cdot}g\;fr\;wt\;nodule^{-1}{\cdot}h^{-1}$ of the nitrogenase activity, respectively. Water stress with 86% decrease of soil water content caused temporary wilting point of leaf and a complete disappearance of nitrogenase activity of nodules, though the water content and transpiration rate in plant were reduced to 90 and 53%, respectively.tively.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.285-293
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• 2018

This study aimed to evaluate the effect of height suppression of cucumber and tomato plug seedlings as affected by mechanical stimulus using brushing as environment-friendly method. Cucumber (Cucumis sativus L. 'Joeunbaekdadagi') and tomato (Solanum lycopersicum L. 'Mini Chal') seeds were sown in 40-cell plug trays ($54{\times}27.5{\times}5cm$) filled with growing medium on Oct. 9, 2017. The cultivation environment in a venlo-type glasshouse was maintained as cultivation temperature range of $15-25^{\circ}C$ and the relative humidity of $50{\pm}10%$. Nontreatment and diniconazole ($7.5mg{\cdot}L^{-1}$) application at 15 days after sowing were used as the control. In addition, brushing treatments in cucumber and tomato were applied interval of 2, 4 or 6 hrs for 15 and 20 days, respectively. Plant height, hypocotyl length, and internode length were inhibited for cucumber and tomato in the diniconazole treatment than in the control. The leaf size was reduced, both cucumber and tomato, while the SPAD increased under the diniconazole treatment. However, stem diameter of cucumber was the thickest in the 2 hrs brushing interval treatment. Fresh weights of shoot and root were the significantly lowest in the diniconazole treatment. Application of brushing improved seedlings quality by promoting dry weights of shoot and root, and compactness of tomato seedlings. The chlorophyll fluorescence of tomato seedlings drastically decreased with 2 hrs treatment, indicating that mechanical stress by brushing treatment. The relative growth rate of tomato seedlings was significantly lower in the diniconazole treatment, but cucumber seedlings were not significantly different in all treatments. As a results, height suppression of cucumber and tomato seedlings was best achievement in the diniconazole treatment by the chemical as growth regulator. In an environment-friendly point of view, however, it is considered that 2 hrs brushing interval treatment can be the applicability for replacing the chemical methods in plug seedling growth of cucumber and tomato.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.6 s.165
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• pp.955-965
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• 2007

Safety helmets are used widely in various industries by workers since they are legally required to wear them. However, thermal discomfort is one of the major complaints from helmet users. To relieve this problem, frozen gelled packs can be considered for use inside the helmets. In this paper, tests were performed on humans to evaluate the physiological strains of wearing safety helmets and to investigate the effects of using frozen gelled packs inside the helmets. Experiments were conducted in a climatic chamber of WBGT $33{\pm}1^{\circ}C$ under four differed experimental conditions: 1) not wearing a safety helmet(NH); 2) wearing a safety helmet with frozen gelled pack A(HA); 3) wearing a safety helmet with frozen gelled pack B(HB); and 4) wearing only a safety helmet(OH). The results were as follows. First, when comparing NH with OH, physiological responses such as $\bar{T}_{sk},\;T_r$, HR and sweat rate were significantly higher in OH and subjective sensations were reported as less hot and more comfortable than NH(p<.05). Second, in regard to the frozen gelled packs inserted inside the safety helmets, some physiological responses in HA were different from those in HB, according to the two different types of packs. HA was hotter, more uncomfortable and less exhausted than HB. However, result from both HA and HB were lower than those from OH in terms of temperature and humidity inside safety helmet, sweat rate, $T_r$ increase, heat storage(p<.05). When wearing safety helmets with frozen gelled packs, it was shown that heat strain can be alleviated. These results are expected to help millions of workers who complain that wearing safety helmets is uncomfortable and messy.