• Korean Journal of Construction Engineering and Management
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• v.23 no.1
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• pp.89-97
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• 2022

Recently, various problems such as reduced productivity, insufficient inflow of skilled manpower, reduced quality, and concerns about increasing safety accidents have appeared in the domestic construction industry. Stakeholder of construction project are considering the Off-Site Construction (OSC) method rather than the conventional on-site construction as an alternative. Despite the importance of decision making in the early stage of the adoption of OSC, there is a lack of methodologies for rational decision making. In this study, a decision making system has been developed to derive the final construction cost score by deriving the project characteristics, selecting the construction difficulty index, and developing a cost model for each construction method alternatives to calculate the standard construction cost. Using this system, the OSC method can be effectively evaluated in terms of its feasibility in the early stage of construction

• Journal of Preventive Medicine and Public Health
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• v.55 no.1
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• pp.98-105
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• 2022

Objectives: Low back pain (LBP) is a common chronic condition among sedentary workers that causes long-term productivity loss. This study aimed to identify the relationships of individual and occupational factors with LBP among Bangladeshi online professionals. Methods: We conducted a cross-sectional study involving 468 full-time online professionals who usually worked in a sitting position. One-month LBP complaints were assessed using a musculoskeletal subscale of subjective health complaints. The chi-square test was used to measure associations between categorical predictors and LBP, and multivariable logistic regression was conducted to identify the variables significantly associated with LBP. Results: LBP within the last month was reported by 65.6% of participants. Multivariable logistic regression analysis indicated that age >30 years (adjusted odds ratio [aOR], 0.40; 95% confidence interval [CI], 0.23 to 0.70) and being married (aOR, 0.59; 95% CI, 0.36 to 0.97) had significant negative associations with LBP. Significant positive associations were found for spending >50 hours weekly on average working in a sitting position (aOR, 1.61; 95% CI, 1.05 to 2.49), being overweight and obese (aOR, 1.87; 95% CI, 1.16 to 2.99), sleeping on a soft mattress (aOR, 2.01; 95% CI, 1.06 to 3.80), and ex-smoking status (aOR, 3.33; 95% CI, 1.41 to 7.87). Conclusions: A high prevalence of LBP was found among full-time online professionals. Long working hours in a sitting position showed a significant association with developing LBP. Smoking history, body mass index, and sleeping arrangements should also be considered while considering solutions for LBP prevalence among online professionals.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.3
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• pp.229-235
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• 1985

Zoning of the agroclimatic regions was attempted based on the distribution of drought index, effective temperature, meteorological factors and their standard deviation and a climatic productivity derived from yield response of rice to temperature and sunshine hours. The meteorological data obtained from synoptic weather stations under the Central Meteorology Office and simple weather observatories under the Rural Development Administration at 155 locations throughout the country were computerized in the PDP11/70, RDA Computer Center, to analyze the climatic similarities among the locations, except the Jeju Island. The nineteen different agroclimatic regions were classified, ego the Taebaeg Mountainous Region. the Charyung Southern Plain Region, etc., and the climatic characteristics of the regions were identified.

• Safety and Health at Work
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• v.14 no.1
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• pp.66-70
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• 2023

Background: Online teaching and learning extend the duration of using gadgets such as mobile phones and tablets. A prolonged usage of these gadgets in a static position can lead to musculoskeletal disorders (MSD). Therefore, this study aims to identify the risk factors related to musculoskeletal symptoms while using gadgets during work from home due to the COVID-19 pandemic. Method: A cross-sectional survey with online-based questionnaires was collected from the University of Indonesia, consisting of lecturers, students, and managerial staff. The minimum number of respondents was 1,080 and was defined by stratified random sampling. Furthermore, the dependent variable was musculoskeletal symptoms, while the independent were age, gender, job position, duration, activity when using gadgets, and how to hold them. Result: Most of the respondents had mobile phones but only 16% had tablets. Furthermore, about 56.7% have used a mobile phone for more than 10 years, while about 89.7% have used a tablet for less than 10 years. A multivariate analysis found factors that were significantly associated with MSD symptoms while using a mobile phone, such as age, gender, web browsing activity, work, or college activities. These activities include doing assignments and holding the phone with two hands with two thumbs actively operating. The factors that were significantly associated with MSD symptoms when using tablets were gender, academic position, social media activity, and placing the tablet on a table with two actively working index fingers. Conclusion: Therefore, from the results of this study it is necessary to have WFH and e-learning policies to reduce MSD symptoms and enhance productivity at work.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.252-252
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• 2022

Genotype-by-environment interaction (GEI) refers to the comparative response of genotypes to different environments conditions. Thus, understanding GEI is a fundamental component for selecting superior genotypes for breeding programs. The significance of utilizing early maturing cultivars not only provides flexibility in planting dates, but also serves as an effective strategy to reduce methane emission from the paddy fields. In this study, we conducted multi-environment trials (METs) to evaluate yield-related traits such as culm length, panicle length, panicle number, spikelet per plant, and thousand grain weight. A total of eighty-one Korean commercial rice cultivars categorized as early maturing cultivars, were cultivated in three regions, two planting seasons for two years. The genotype main effect plus genotype-by-environment interaction (GGE) biplot analysis of yield-related traits and grain yield explained 70.02-91.24% of genotype plus GEI variation, and exhibited various patterns of mega-environment delineation, discriminating ability, representativeness, and genotype rankings across the planting seasons and environments. Moreover, simultaneous selection using weighted average of absolute scores from the singular value decomposition (WAASB) and multi-trait stability index (MTSI) revealed six highly recommended genotypes with high stability and crop productivity. The winning genotypes under specific environment can be utilized as useful genetic materials to develop regional specialty cultivars, and recommended genotypes can be used as elite climate-resilient parents to improve yield-potential and reduce methane emission as part to accomplish carbon-neutrality.

• Korea Trade Review
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• v.48 no.4
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• pp.121-148
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• 2023

The rapid melting of Arctic sea ice has increased interest in the Northern Sea Route (NSR) as a viable alternative trade route between Europe and Asia. While extensive research has examined its competitiveness in terms of technical feasibility, safety, profitability, and environmental impact, the topic of the NSR ports remains relatively underrepresented in the literature. Hence, this study aims to contribute to the existing research by assessing the efficiency of 17 NSR ports to gain insights into their operations and identify areas for improvement using models of Data Envelopment Analysis(DEA). The obtained results show that efficient ports mainly belong to the western NSR region, with ports like Murmansk and Varandei consistently demonstrating high efficiency and constant returns to scale. Several ports, such as Onega, Arkhangelsk, Naryan-Mar, and Khatanga, showed inefficiencies in the utilization of berths and quay lengths. The findings not only contribute to academic knowledge but also offer practical implications for NSR port authorities, assisting them in making well-informed decisions regarding infrastructure development plans.

• Korean Journal of Environment and Ecology
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• v.30 no.6
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• pp.1022-1031
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• 2016

Relationships of standing biomass with biodiversity and structural diversity were examined in the Quercus mongolica-dominated forest in Mt. Jeombong, Gangwon-do. We examined the standing biomass of the Q. mongolia community ($311.1ton{\cdot}ha^{-1}$) from 2004 to 2013, and the observed major species were Q. mongoilca, Carpinus cordata, Tilia amurensis whose standing biomasses were $206.3ton{\cdot}ha^{-1}$ (66.3%), $36.9ton{\cdot}ha^{-1}$ (11.9%), and $30.6ton{\cdot}ha^{-1}$ (9.8%), respectively. Although the number of Q. mongolica individuals was very small compared with total density, the reason that Q. mongolica showed the most biomass than other species is due to greater average diameter at breast height (DBH) and the higher number of $DBH{\geq}50cm$ individuals. We calculated the range of Shannon index (H') and Shannon evenness (J') in the Q. mongolica community, and they were gradually increased in time, showing 2.015~2.166, 0.673~0.736, respectively. Their H' and J' showed positive linear relationships with their standing biomass. This indicates that the spatial distribution of the standing biomass in Q. mongoilca community becomes more homogeneous with time and this homogenization appears in various species in the community. In addition, we estimated biomass-species index (BS) and abundance-biomass-speciesdiversity (ABS) and they also showed gradual increase in time, ranging from 3.746 to 3.811 and from 4.781 to 5.028, respectively. Their indices showed positive linear relationships with the standing biomass. This can be explained from the observations of variations in standing biomass with tree diameters as the differences in the average standing biomass in the community have reduced gradually in time. Moreover, it is expected that increase in the structure diversity of the Q. mongoilca community enhances the efficiency in carbon sequestration and productivity, so the community can be developed to a more sustainable ecosystem with more abundant resources. Thus, applications of uneven-aged plantations with considerations of local ecological properties can be a very efficient reforestation method to ensure stable support of biodiversity and productivity.

• The Journal of Pediatrics of Korean Medicine
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• v.14 no.1
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• pp.39-78
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• 2000

Introduction: In order to investigate the effects of partial Cervus elaphus Linne' extract on antitumoral immunological, a group of mice are melanoma-induced and observed reponses in terms of the number of lymphocyte, CD4+ count, CD8+ count, CD4+/CD8+ ratio in blood and spleen, change in body weight, melanoma weight, spleen index, NK cell activity and productivity of IL-2 in each mouse Methodology: Male C57BL/6 mice were chosen as an experimental object and were divided into 5 groups randomly selection. The normal group did not receive any induction. The control group was treated with normal saline in melanoma-induced' mice. Sample I group induced the upper part of Cervus elaphus Linne' extract in melanoma-induced mice. Sample II group was induced the middle part of Cervus elaphus Linne' extract in melanoma-induced mice. Sample III group was induced the lower part of Cervus elaphus Linne' extract in melanoma-induced mice. The dosage of medication was 0.2cc daily for 14days. Results: 1. There was a significant difference in the number of lymphocyte in spleen in the sample I (upper part of Cervus elaphus Linne' extract induced) and the sample II (middle part of Cervus elaphus Linne' extract induced) compared to the control group and the sample III (lower part of Cervus elaphus Linne' extract induced). On the other hand, no significant difference was observed in the number of lymphocyte in blood in the control group and all sample groups. 2. In the CD4+ T cell ratio in blood, all three sample groups showed differences compared to the control group, though there was no significant difference between sample groups. In the CD4+ T cell ratio in spleen, there was a difference between the sample I and the control group, while the sample II and the sample III had significant difference to the control group. And also, it has been observed there were differences between the sample I and the other samples. 3. In the CD8+ T cell ratio in spleen, all three sample groups showed significant differences compared to the control group, while there was no difference between groups in the ratio in blood. 4. In the CD4+/CD8+ T cell ratio in blood, the sample I showed a significant difference compared to the control group, while the sample 1I and sample III showed differences compared to the control group. In the CD4+/CD8+ T cell ratio in spleen, all three samples showed a significant difference compared to the control group, when the sample I had a difference to the other sample groups. 5. The spleen index of the sample I and the sample II showed a significant difference compared to the sample III and the control group. In comparison between the sample groups, the sample I and the sample II showed a significant difference to the sample III. 6. In terms of the change in body weight and melanoma weight, all three sample groups showed a significant difference compared to the control group, while the comparison between the sample groups showed the sample and the sample II had a significant difference to the sample Ⅲ. 7. In comparison of NK cell activity, the sample I had a difference compared to the other groups when the effector to target cell ratio was 2.5:1. With the ratio of 5:1, the sample I and sample II showed significant differences compared to the control group, while the sample Ⅲ showed a difference. When the effector to target cell ratio was 10:1, there was no difference between groups. 8. In the productivity of IL-2, all three sample groups showed significant differences compared to the control group. In comparison between sample groups, there were significant differences between each sample groups in order of the sample I , the sample II and the sample Ⅲ. Conclusion: As one can witness from the above results, administration of partial Cervus elaphus Linne extract played important role in antitumoral immune response in melanoma-induced mice, and it could be suggested that sample I and sample II groups have prominent antitumoral immune effect.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.245-252
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• 2018

Yam bean (Pachyrhizus erosus) is a subtropical plant belonging to the Fabaceae family, and is a tuberous vegetable used as various food material with a crisp and juicy taste. This study was conducted to seek optimum sowing time of yam bean in Korea. For this, we surveyed germination properties by the different temperatures and compared the accumulation temperature (AT) and dry matter production (DMP) on growth stages of yam bean by the different sowing times. Two types of varieties cultivated mainly in Korea, Thailand local variety (TLV) and Cheongunmanma cultivar (CGMM), was used. The germination rate of yam bean was 86.0~94.0% at above $18^{\circ}C$, and germination days was longer at lower temperature. The times for flowering and tuber formation of CGMM were later than those of TLV, and the AT required for flowering, tuber formation and hypertrophy of CGMM were higher than those of TLV by $293^{\circ}C$, $280^{\circ}C$ and $108^{\circ}C$, respectively. Also, DMP of shoot and tuber in CGMM were greater than those in TLV. In sowing at April 25, tuber formation was slower than sowing after that time, and harvest index (HI) was relatively low due to delayed formation and hypertrophy of tuber. In sowing after June 9, DMP of shoot was relatively greater in early growth, but tuber was not sufficient to enlarge due to lack of growth days by cold and frost in late October. In sowing May 10 and 25, DMP of tuber and HI were the highest, because the change of day length and temperature gave an advantage to vegetable growth and tuber development. All above suggest that it was suitable to sow seeds on May for increment of tuber productivity in Korea.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.2
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• pp.43-53
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• 2017

This study aims to analyze the effect of typhoons on pear production. Pears are typical fruits that are vulnerable to typhoon damages, so typhoons are negatively associated with pear productivity. However, relatively less pear damages by typhoons in the main pear production area, comparing to the average in Korea, have been reported. The main production area seems to adopt better agricultural techniques or practices to cope with natural disasters such as typhoons. Thus, this study tests the hypothesis that there are differences of production losses due to typhoons between the main pear production area and the rest using the stochastic frontier analysis. The main production area is defined by Location Quotient Index (LQI), and we found that LQI had a significant effect to decrease the productivity losses in the main production areas, which shows that those production areas alleviated the pear production loss due to typhoons.