• Journal of Korea Water Resources Association
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• v.53 no.1
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• pp.15-27
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• 2020

Streamflow discharge as a fundamental riverine quantity plays a crucial role in water resources management, thereby requiring accurate in-situ measurement. Recent advances in instrumentations for the streamflow discharge measurement has complemented or substituted classical devices and methods. Among various potential methods, surface current meter using microwave has increasingly begun to be applied not only for flood but also normal flow discharge measurement, remotely and safely enabling practitioners to measure flow velocity postulating indirect contact. With minimized field preparedness, this method facilitated and eased flood discharge measurement in the difficult in-situ conditions such as extreme flood in active ways emitting 24.125 GHz microwave without relying on natural lights. In South Korea, a rectangular shaped instrument named with Microwave Water Surface Current Meter (MWSCM) has been developed and commercially released around 2010, in which domestic agencies charging on streamflow observation shed lights on this approach regarding it as a potential substitute. Considering this brand-new device highlighted for efficient flow measurement, however, there has been few noticeable efforts in systematic and comprehensive evaluation of its performance in various measurement and riverine conditions that lead to lack in imminent and widely spreading usages in practices. This study attempted to evaluate the MWSCM in terms of instrumen's monitoring configuration particularly regarding tilt and yaw angle. In the middle of pointing the measurement spot in a given cross-section, the observation campaign inevitably poses accuracy issues related with different tilt and yaw angles of the instrument, which can be a conventionally major source of errors for this type of instrument. Focusing on the perspective of instrument configuration, the instrument was tested in a controlled outdoor river channel located in KICT River Experiment Center with a fixed flow condition of around 1 m/s flow speed with steady flow supply, 6 m of channel width, and less than 1 m of shallow flow depth, where the detailed velocity measurements with SonTek micro-ADV was used for validation. As results, less than 15 degree in tilting angle generated much higher deviation, and higher yawing angle proportionally increased coefficient of variance. Yaw angles affected accuracy in terms of measurement area.

• Tuberculosis and Respiratory Diseases
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• v.60 no.5
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• pp.554-563
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• 2006

Background: PM is known to induce various pulmonary diseases, including asthma, cancer, fibrosis and chronic bronchitis. Despite the epidemiological evidence the pathogenesis of PM-related pulmonary diseases is unclear. Methods: This study examined the effects of PM exposure on the secretion of $TNF-{\alpha}$ and $IL-1{\beta}$ in the cultured alveolar macrophages. The cultured primary alveolar macrophages were treated with the medium, PM ($5{\sim}20{\mu}g/cm^2$), LPS (5ng/ml), and PM with LPS for 24h and 48h respectively. ELISA was used to assay the secreted $TNF-{\alpha}$ and $IL-{\beta}$ in the culture medium. Western blotting was used to identify and determine the level of proteins isolated from the culture cells. The cells cultured in the $Lab-Tek^{(R)}$ chamber slides were stained with immunocytochemical stains. Results: PM induced $TNF-{\alpha}$ and $IL-1{\beta}$ secretion in the culturing alveolar macrophages, collected from the SPF and inflammatory rats. However, the effects were only dose-dependent in the inflammatory macrophages. When the cells were co-treated with PM and LPS, there was a significant synergistic effect compared with the LPS in the both cell types. Conclusion: PM might be play an important role in the induction and/or potentiation of various lung diseases by oversecretion of $TNF-{\alpha}$ and $IL-1{\beta}$.

• The Journal of Korean Society for School & Community Health Education
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• v.17 no.1
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• pp.89-99
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• 2016

Objectives: This cross-sectional study aims to investigate the prevalence and factors relating to handwashing with soap among Korean adults. Methods: Study subjects consist of 755 adults who have been contacted in September 2013 via telephone surveys. The data collected has been analyzed using descriptive statistics, a chi-square test and a logistic regression analysis. A primary purpose is to understand the prevalence of handwashing with soap more than 8 times daily and for 30 seconds per wash among adults. Independent variables include socioeconomic levels, the participants' perception and knowledge of handwashing and their educational experiences relating to handwashing. Results: The overall percentile of people who wash their hands with soap 8 time per day for 30 seconds or more per wash was 16.0%, which is 121 people out of 755 study subjects. In univariate analysis, age, education levels, monthly average income, handwashing habits, perceptions relate to the importance of handwashing, self-assessment of handwashing, environment of public toilet, and the completion of handwashing education shows significant result. Significant differences also appear (p<0.05) in logistic regression analysis on binary variables. There is a strong correlation between daily frequency of handwashing and willingness to wash hands while outside. For example, people who wash their hands very often while outside are 2.24 times (95% C.I. 1.29-3.87) more likely to practice handwashing with soap 8 times per day for 30 seconds or more per wash than those people who only intermittently wash their hands while outside. Furthermore, people with general unwillingness to wash their hands while outside are 4.61 times (95% C.I. 1.22-3.28) less likely to practice handwashing with soap 8 times per day for 30 seconds or more per wash than those with general willingness. Conclusions: This study has been carried out to identify the decision factors in practicing handwashing with soap for Korean adults. In univariate analysis, age, education level, monthly average income, handwashing habits, handwashing self-assessment, public toilet environment, completion of handwashing education and so forth have been identified to be the decision factors. This study result shows that the overall level of cleanliness of public toilet perceives to be poor and it suggests that the environment of public toilet needs to be enhanced. As the handwashing habits and handwashing-self assessment have been identified to be the significant decision factors for handwashing, there search and approach in these factors need to be developed further.

• Journal of the Korean Wood Science and Technology
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• v.17 no.3
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• pp.8-19
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• 1989

The proportion of imported wood has been now over 80% of raw materials needed in the wood industry, and therefore, many of studies on the substitution of domestic wood for imported wood and on the increasing the utilization rate of domestic species have been attempted and considered as very important projects to solve. But these trials were practically restricted by several disadvantages of domestic species. such as a small diameter, variety of species, and irregularity of wood physical or chemical characteristics, etc. From a this point of view, this study was carried out to investigate solid wood bending properties of sample trees and then to develop their end uses. The species of sample trees were Pinus densiflora S. et Z., Pinus rigida Mill., and Larix leptolepis Gord. which have large growing stocks but Pinus rigida and Larix leptolepis have not been used well because of their poor qualities. The results obtained were as follows: 1. The optimum conditions for solid wood bending processing of Pinus densiflora, Pinus rigida, and Larix leptolepis are showed in Table 6. 2. The minimum solid-bending radii of Pinus densifjora, Pinus rigida, and Larix ieptolepls were 260mm, 240mm, and 300mm, respectively in steaming treatment.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.2
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• pp.34-45
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• 2016

Global warming and climate change have been caused by combustion of fossil fuels. The greenhouse gases contributed to the rise of temperature between $0.6^{\circ}C$ and $0.9^{\circ}C$ over the past century. Presently, fossil fuels account for about 88% of the commercial energy sources used. In developing countries, fossil fuels are a very attractive energy source because they are available and relatively inexpensive. The environmental problems with fossil fuels have been aggravating stress from already existing factors including acid deposition, urban air pollution, and climate change. In order to control greenhouse gas emissions, particularly CO2, fossil fuels must be replaced by eco-friendly fuels such as biomass. The use of renewable energy sources is becoming increasingly necessary. The biomass resources are the most common form of renewable energy. The conversion of biomass into energy can be achieved in a number of ways. The most common form of converted biomass is pellet fuels as biofuels made from compressed organic matter or biomass. Pellets from lignocellulosic biomass has compared to conventional fuels with a relatively low bulk and energy density and a low degree of homogeneity. Thermal pretreatment technology like torrefaction is applied to improve fuel efficiency of lignocellulosic biomass, i.e., less moisture and oxygen in the product, preferrable grinding properties, storage properties, etc.. During torrefacton, lignocelluosic biomass such as palm kernell shell (PKS) and empty fruit bunch (EFB) was roasted under an oxygen-depleted enviroment at temperature between 200 and $300^{\circ}C$. Low degree of thermal treatment led to the removal of moisture and low molecular volatile matters with low O/C and H/C elemental ratios. The mechanical characteristics of torrefied biomass have also been altered to a brittle and partly hydrophobic materials. Unfortunately, it was much harder to form pellets from torrefied PKS and EFB due to thermal degradation of lignin as a natural binder during torrefaction compared to non-torrefied ones. For easy pelletization of biomass with torrefaction, pellets from PKS and EFB were manufactured before torrefaction, and thereafter they were torrefied at different temperature. Even after torrefaction of pellets from PKS and EFB, their appearance was well preserved with better fuel efficiency than non-torrefied ones. The physical properties of the torrefied pellets largely depended on the torrefaction condition such as reaction time and reaction temperature. Temperature over $250^{\circ}C$ during torrefaction gave a significant impact on the fuel properties of the pellets. In particular, torrefied EFB pellets displayed much faster development of the fuel properties than did torrefied PKS pellets. During torrefaction, extensive carbonization with the increase of fixed carbons, the behavior of thermal degradation of torrefied biomass became significantly different according to the increase of torrefaction temperature. In conclusion, pelletization of PKS and EFB before torrefaction made it much easier to proceed with torrefaction of pellets from PKS and EFB, leading to excellent eco-friendly fuels.

• Tuberculosis and Respiratory Diseases
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• v.60 no.4
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• pp.426-436
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• 2006

Background : Particulate matters (PM) when inhaled is known to induce pulmonary diseases including asthma and chronic bronchitis when inhaled. Despite the epidemiological proofevidence, the pathogenesis of PM-related pulmonary diseases is unclearremain poorly understood. Methods : Primary alveolar macrophages were harvested from the SPF and inflammatory rats by bronchioalveolar lavage (BAL). The cultured primary alveolar macrophages were treated with the medium only, PM only ($5{\sim}40{\mu}g/cm^2$), LPS (5ng/ml) only, and PM with LPS for 24 and 48 hours. The level of secreted nitric oxide (NO) was assayed from the cultured medium by using the Griess reaction. The cultured cells were utilized for the western blotting against the inducible nitric oxide synthase (iNOS) proteins. Immunocyto- chemical staining against the iNOS and NT-proteins were performed in cells that cultured in the $Lab-Tek^{(R)}$ chamber slide after treatments. Results : The PM that utilizein this experiments induced NO formation with iNOS expression in the cultured SPF and inflammatory rats alveolar macrophages, by itself. When the cells were co-treated with PM and LPS, there was a statistically significant synergistic effect on NO formation and iNOS expression over the LPS effect. The cells from the sham control showed minimal immunoreactivity for the NT-proteins. Significantly higher quantities of NT-proteins were detected in the PM and PM with LPS co-treated cells than from the sham control. Conclusion : Increased iNOS expression and NO formation with increased NT-proteins formation might be involved in the pathogenesis of PM-induced lung injury.

• Journal of agricultural medicine and community health
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• v.40 no.4
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• pp.206-220
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• 2015

Objectives: The purpose of this study was to investigate the association between practice and infectious diseases in elementary, middle and high school students. Methods: In 16 metropolitan cities and province of the Korea, the students who from fourth grade of elementary school to third grade of high school were surveyed by personal interviews and an web-based online survey from 5 to 25 September, 2014. We analyzed data with chi-square test and logistic regression analysis. Results: Common cold, diarrhea, and eye infections were more prevalent among students in higher grade than lower grade. In particular, common cold was more prevalent among girls than boys, using hand sanitizer than washing with soaps, and students who wash the dorsal side of hand than not wash the dorsal side of hand. Conclusions: Higher-grade students showed low status of hand washing practice. Hand washing was determined as the fact which influences to increase the prevention of communicable disease such as common cold. Considering the fact that youth groups have higher risk of being infected due to their group life, schools are recommended to provide adequate educations regarding proper hand washing practice with soap.

• Journal of the Korean Wood Science and Technology
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• v.8 no.1
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• pp.13-21
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• 1980

This experiment was carried out to investigate the effect of heating periods on the physical and mechanical properties of maple (Acer mono Max.) by oven heating and heating in water at 100$^{\circ}C$ for 0, 2, 4, and 6 days respectively. The results obtained are summarized as follows: 1. The green volume specific gravity due to oven heating decreased from 6 days of exposure, and that, due to heating in water decreased from 4 days of exposure. 2. The radial shrinkage due to oven heating decreased from 2 days of exposure, but that due to heating in water increased from 6 days of exposure. The tangential shrinkage due to oven heating decreased from 2 days of exposure, but that due to heating in water increased from 2 days of exposure. 3. The amount of water absorption due to oven heating decreased from 2 days of exposure, but that due to heating in water increased from 4 days of exposure. 4. The compressive strength pararelled to grain due to oven heating increased till 4 days of exposure but decreased from 6 days, and that due to heating in water decreased from 2 days of exposure. 5. The shearing strength pararelled to grain due to oven heating increased till 2 days of exposure, but decreased from 4 days of exposure, and that due to heating in water decreased from 4 days of exposure. 6. The bending strength due to oven heating increased till 4 days of exposure but decreased from 6 days, and that due to heating in water decreased from 6 days of exposure. The impact bending absorbed energy due to oven heating decreased from 4 days of exposure, and that due to hearing in water decreased from 2 days of exposure.

• Journal of Wetlands Research
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• v.19 no.2
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• pp.230-239
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• 2017

These days, the demand of farm tours is on the rise in Korea. However, most of them are related to farming experience. To overcome the situation, ecological experience is introduced. In this sense, it is necessary to obtain the contents and educational materials of ponds, the space of farming and ecological experience. Therefore, this study analyzed the use patterns of oriental medicine of pond wetland plants. Oriental medicine is used for old and traditional knowledge, and is still applied to various fields, such as medical science, pharmacy, and science. The analyzed result of this study will be helpful for the educational materials of ecological experience. This study surveyed plants of 40 pond wetlands in rural areas, and looked into the use patterns of traditional medicine by using the contents of Korea Traditional Knowledge Portal being operated by Korean Intellectual Property Office. According to the vegetation survey of the 40 pond wetlands, there were a total of 457 taxa in 108 families, 309 genera, 392 species, 59 varieties, 5 forma, and 1 subspecies. Among them, 314 taxa in 53 families, 136 genera, 265 species, 45 varieties, 3 forma, and 1 subspecies had the information on the use patterns of traditional medicine. It means that 68.8% of the plants around pond wetlands contain traditional medicine. Given other application patterns, such as food, handcraft and traditional farming, more than 70~80% are expected to include traditional knowledge. 314 taxa used for traditional medicine had 570 kinds of efficacy and 325 kinds of disease treatment. It means that one taxon has 4.0 (0~20) kinds of efficacy on average and 6.6(0~20) kinds of disease treatment. It is expected that this study result will be applied to various fields, including experience, education, and medical science. And it is considered that valuable pond wetlands are worthwhile to be conserved constantly.

• Korean journal of applied entomology
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• v.24 no.4 s.65
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• pp.195-201
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• 1986

This study was conducted to investigate the life history of Compsidia populnea which is major species of the stem-borers on Populus alba{\times}glandulosa$. Peak emergence of the adult of Compsidia populnea L. was around 10th${\sim}$l2nd of May in Chuncheon vicinities, having one generation a year in Korea. There was a preovipositional period of 10.7 days and a ovipositional period of 14.3.days. Mean adult longevity was 11 days for male and 13.8 days for female. Individual eggs were long oval with somewhat narrowed tip at one side and soft, 2.6mm in length, 0.8mm in diameter, and were laid singly under the U-shaped scars which were made by female before oviposition. Total number of scars per female averaged 56.6 ($8{\sim}135$) and eggs were found in 67.9 percent of the total scars. Egg period was $8{\sim}11$ days at $25^{\circ}C$ constant temperature and $7{\sim}14$ days in the field condition. Early young larvae stayed for $2{\sim}3$ weeks under the scars and then boring into the xylem, forming galls at this time. Size of the gall was 1.8cm($1.3{\sim}2.5$) in length, 1.6cm($1.0{\sim}2.2$) in diameter and the length of mine was everage 3.1cm. Fully grown larvae were developed around the early October and overwintered in the mines of galls. Pupation was done around the early of April. Pupal developmental period averaged 11 days($9{\sim}13$ days) at $25^{\circ}C$ constant temperature condition.