• Journal of the Korean Society of School Health
• /
• v.12 no.2
• /
• pp.321-337
• /
• 1999

The purpose of this study was to obtain basic data for the prevention and control of adolescent back pain through analyzing connections between study environments and physical posture. The subjects were 960 male general high school students in the Chonju area and the data were collected by a self-reported questionnaire from Mar. 17 to Mar. 22, 1999. The collected data were analyzed by a frequency, chi-square and t-test using an SPSS program. The results are as follows; 1) The experience rate of back pain perceived by subjects was 67.5% and by each grade: 1st-27.5%, 2nd-35.4%, 3rd-37.1%. The relationship between grades and the experience of back pain didn't show any significant difference. 2) The causes of back pain perceived by subjects such as 'postures are not good' was 56.7%, 'sitting too much time in a chair' was 39.1%, and 'too severe exercise' was 32.4%. 27.8% had back pain first during the 3rd grade of middle school, and 23.9% had it first during the 1st grade of high school. 3) Intensity of subjects' back pain spread from 'moderate' at 49.6%, to 'severe' at 16.4%. Concerning the frequency of back pain, 58.6% said it was 'irregalar'. 4) Among interventions to deal with back pain: 'move by exercising my back or ask friends to beat my back' was 41.0%, 'just bear it' was 23.1%, and at home 'don't have 'any treatment' was ranked first, at 54.9%. 5) The relationship between subjects' general characteristics and back pain experiences: height (t=-1.99, P=.046), sitting/height (t=-2.61, P=.009), self-perceived condition of health (${\chi}^2=23.530$, P=.000), family history (${\chi}^2=43.903$, P=.000) showed significant difference, but the kinds of transportation, sleeping postures, sleeping method and smoking didn't show significant differences. 6) The relationship between subjects' learning environment and back pain experiences, the height of students' desk and chair showed significant difference (${\chi}^2=23.054$, P=.000), but the sitting time didn't show significant difference. 7) The relationship between the characteristics of subjects' physical postures and back pain experiences: standing postures (${\chi}^2=15.105$, P=.001), and sitting postures (${\chi}^2=20.264$X2, P=.001) showed significant difference, but lifting postures didn't show significant difference.

• The Journal of Korean Association of Computer Education
• /
• v.16 no.3
• /
• pp.49-60
• /
• 2013

This study is aimed to investigate that the blended e-learning could enhance the effectiveness compared to the conventional lecture performed in classroom. At first, both the CbE(Class based E-learning) and the EbC(E-learning based Class) mode have been generated in blended e-learning operation method following the process which analyze the various studies of interest. In addition, the instruction structures of Z Type(Zigzag model) and H-Type(Ladder model) were established as proposed model. The H-Blended e-learning based on CbE mode was introduced in the Excel Spread Sheet subject which held in A University to achieve the goal of this study. Learners were categorized and belonged to either the group 1(over 50% of attendance in cyber lecture) or the group 2(the rest of them). The data analysis was performed with $x^2$-test, t -test to compare the achievement of study between groups. The t -test result showed that the academic achievement in learning with group 1 was statistically significant than the learner in group 2. The effectiveness of the blended e-learning has been proved as the logistic regression analysis showed that the rate of the attendance in the cyber lecture functioned as indicator that enable to predict the acceptance.

• Journal of Korean Society of Forest Science
• /
• v.97 no.1
• /
• pp.1-9
• /
• 2008

It is necessary to examine relationship between spatial patterns of forest types and characteristics of forest fires for efficient management of fire and forest. By the ecoregions of South Korea, we computed landscape indices for whole types of forests(landscape level) and pine forests(class level), and analyzed characteristics of forest fires using statistics of forest fires from 1991 to 2006. We performed canonical correlation analysis to model the relationship between the landscape indices and the statistics of forest fires. At landscape level, forest patches were larger and more complex in the ecoregions which had higher percentage of forest area. At class level, pine forest patches were more complex and closer to neighbor patches in the coastal ecoregions. The ecoregions including metropolitan areas and cities had more frequent fire occurrences per 1,000ha, while mountainous coastal ecoregions had more burned areas and faster spread of fire growth rate. The canonical correlation between the landscape indices for pine forests and the statistics of forest fires was statistically significant at the 0.05 level and explained more than 70% of the variation in fire variables. The results showed that combustion time per fire was longer in the ecoregions which had larger and more aggregated pine forest patches.

• Journal of Veterinary Clinics
• /
• v.22 no.1
• /
• pp.43-49
• /
• 2005

The aim of this study is to investigate the wound healing effects of the Opuntia ficus-indica. Four full-thickness skin wounds(2.5 cm × 2.5 cm) were made in different areas on the back in each of five dogs. Two wounds were used for wound size measurement and two for skin biopsy. The ten full-thickness wounds were treated with the extract of Opuntia ficus-indica, and the ten full-thickness wounds were treated with normal saline. The wound areas were measured every other day for three weeks after wounding. Statistical analysis was performed with the paired t-test. The wound healing rates were 32.9±4.0%, 28.2±7.1%, 42.2±4.1%, 55.0±4.3%, 76.6±2.8%, 86.8±2.3%, 94.0±1.l%, 97.3±0.8%, 99.3±0.3%, 99.8±0.2%, 100.0±0.0% in the experimental group, and 18.0± 8.2%, 13.S± 11.6%, 15.2±6.1 %, 36.9±8.8%, 62.4±4.1%, 80.0±2.3%, 86.0±1.4%, 94.0±0.9%, 96.9±0.8%, 97.8±0.3%, 99.7±0.1% in the control group on the 1/sup st/, 3/sup rd/, 5/sup th/, 7/sup th/, 9/sup th/, 11/sup th/, 13/sup th/, 15/sup th/, 17/sup th/, 19/sup th/, 21/sup st/ day. On the 17/sup th/ day, the wound closed above 99.9% in 1 dog of the experimental group. On the 19/sup th/ day, the wound closed above 99.9% in 3 dogs of the experimental group. On the 21/sup st/ day, the wound closed above 99.9% in 5 dogs of the experimental group, and 1 dog of the control group. The wound healing period was shortened by 2 to 4 days in the experimental group as compared with the control group. The tensile strength was 4,508±513 g/㎠ in the experimental group and 2,772±400 g/㎠ in the control group on the 21/sup st/ day after wounding. The tensile strength was significantly higher in the experimental group than in the control group(p< 0.05). Inflammation rapidly spread and disappeared in the experimental group but not in the control group. Fibroblast and vascularization were found on the 5/sup th/ day in both group and increased only in the experimental group on the 9/sup th/ day. The firs finding of epithelialization was on the 13/sup th/ day in the experimental group and the 21/sup st/ day in the control group. A significantly higher wound healing rate(p< 0.05), tensile strength(p< 0.05) and better histopathological findings were observed in the experimental group than in the control group throughout the experimental period. These results suggest that topical application of Opuntia ficus-indica extract can promote wound healing in dogs.

• Pediatric Infection and Vaccine
• /
• v.27 no.1
• /
• pp.1-10
• /
• 2020

A cluster of severe pneumonia of unknown etiology in Wuhan City, Hubei province in China emerged in December 2019. A novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was isolated from lower respiratory tract sample as the causative agent. The current outbreak of infections with SARS-CoV-2 is termed coronavirus disease 2019 (COVID-19) by the World Health Organization (WHO). COVID-19 rapidly spread into at least 114 countries and killed more than 4,000 people by March 11, 2020. WHO officially declared COVID-19 a pandemic on March 11, 2020. There have been 2 novel coronavirus outbreaks in the past 2 decades. The outbreak of severe acute respiratory syndrome (SARS) in 2002-2003 caused by SARS-CoV had a case fatality rate of around 10% (8,098 confirmed cases and 774 deaths), while Middle East respiratory syndrome (MERS) caused by MERS-CoV killed 858 people out of a total 2,499 confirmed cases between 2012 and 2019. The purpose of this review is to summarize known-to-date information about SARS-CoV-2, transmission of SARS-CoV-2, and clinical features of COVID-19.

• Journal of Plant Biotechnology
• /
• v.38 no.2
• /
• pp.105-116
• /
• 2011

Transgenic zoysiagrass (Zoysia japonica Steud.) expressing the bar gene inserted in the plant genome has been generated previously through Agrobacterium tumefaciens-mediated transformation. The GM zoysiagrass (event: JG21) permits efficient management of weed control of widely cultivated zoysiagrass fields, reducing the frequency and cost of using various herbicides for weed control. Now we have carried out the environmental risk assessment of JG21 prior to applying to the governmental regulatory agency for the commercial release of the GM turf grass outside of test plots. The morphological phenotypes, molecular analysis, weediness and gene flow from each test plot of JG21 and wild-type zoysiagrasses have been evaluated by selectively analyzing environmental effects. There were no marked differences in morphological phenotypes between JG21 and wild-type grasses. The JG21 retained its stable integration in the host plant in T1 generation, exhibiting a 3:1 segregation ratio according to the Mendelian genetics. We confirmed the copy number (1) of JG21 by using Southern blot analysis, as the transgenic plants were tolerant to ammonium glufosinate throughout the culture period. From cross-fertilization and gene flow studies, we found a 9% cross-pollination rate at the center of JG21 field and 0% at distances over 3 m from the field. The JG21 and wild-type zoysiagrass plants are not considered "weed" because zoysiagrasses generally are not dominant and do not spread into weedy areas easily. We assessed the horizontal gene transfer (HGT) of the transgene DNA to soil microorganisms from JG21 and wild-type plants. The bar gene was not detected from the total genomic DNA extracted from each rhizosphere soil of GM and non-GM Zoysia grass fields. Through the monitoring of JG21 transgene's unintentional release into the environment, we found no evidence for either pollen mediated gene flow of zoysiagrass or seed dispersal from the test field within a 3 km radius of the natural habitat.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.31 no.4
• /
• pp.321-329
• /
• 2013

Despite the advantage of unlimited access, there are insufficient studies for the accuracy and stability of FKP that blocks the spread of the system for various applications. Therefore, we performed a long-term analysis from continuous real-time positioning, and investigated the error characteristics dependent on the size and the surrounding environment. The FKP shows significant changes in the positioning accuracy at different times of day, where the accuracy during daytime is worse than that of nighttime. In addition, the size and deviation of FKP correction may change with the ionospheric conditions, and high correlation between ambiguity resolution rate and the deviation of correction was observed. The receivers continuously request the correction information in order to cope with sudden variability of ionosphere. On the other hand, the correction information was not received up to an hour in case of stable ionospheric condition. It is noteworthy that the outliers of FKP are clustered in their position with some biases. Since several meters of errors can be occurred for kinematic positioning with FKP, therefore, it is necessary to make appropriate preparation for real-time applications.

• Korean Journal of Environmental Agriculture
• /
• v.36 no.4
• /
• pp.299-305
• /
• 2017

BACKGROUND: Although the filamentous fungal pathogen Colletotrichum species causing anthracnose disease on various fruits including peach, apple, persimmon and grape, there is no report on Japanese plum in Korea. METHODS AND RESULTS: In 2016, diseased fruits showing typical anthracnose symptoms of Japanese plum were collected in market and ochards. Diseased tissue was cut off and disinfected subsequently with 70% ethanol for 1 min, and in 1% sodium hypochloride solution for 1 min, followed by three washes with sterile distilled water. The disinfected tissues were placed onto potato dextrose agar (PDA), and incubated at $25^{\circ}C$ in the dark for 5 to 7 days. For single-spore isolation, conidia were scraped off the plate using a loop, and suspended with 10 mL sterile distilled water. One hundred microliter of the conidial suspension was spread on PDA plates and incubated at $25^{\circ}C$. Finally, one germinated conidium was transferred onto PDA plates. Morphological and cultural characteries of colonies and spores of isolated Colletotrichum were observed after 7 to 10 days incubation on PDA. Molecular identification of isolates were analyzed by comparing rDNA-ITS gene sequences with NCBI GeneBank. CONCLUSION: Of eleven isolates of Colletotrichum isolated from anthracnose diseased Japanese plum fruits, six were identified as C. acutatum, and five as C. gloeosporioides based on diagnostic characteristics such as colony growth rate, shape and size of conidia, and rDNA-ITS sequences. This is the first report of Colletotrichum causing the anthracnose on Japanese plum in Korea.

• Korean Journal of Environmental Biology
• /
• v.36 no.2
• /
• pp.232-240
• /
• 2018

This study was performed to investigate the effects of water temperature and salinity on the egg development and larval attachment of Ascidiella aspersa. The egg development and larval attachment were examined in 12 different water temperatures (6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26 and $28^{\circ}C$) and two salinity conditions(30 and 34 psu). The hatching and developmental rates of A. aspersa showed a tendency to increase with increasing water temperature regardless of salinity and to decrease after the optimal water temperature range. The optimal water temperatures for the hatching and development of egg of A. aspersa were in the range of $20-22^{\circ}C$. The low threshold water temperature was not different between 1.5 and $1.8^{\circ}C$ at 30 and 34 psu, respectively. The attachment rate showed the optimal water temperature range of $16-22^{\circ}C$ irrespective of the salinity and the attachment time increased continuously with increasing water temperature. Experimental results showed that optimum development and survival temperature of the egg and larvae of A. aspersa were in the range of $20-22^{\circ}C$ regardless of the salinity conditions. The results can be used to predict the distribution and occurrence of A. aspersa, and to prevent economic damages caused by its spread.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.4
• /
• pp.480-488
• /
• 2016

As the subprime mortgage crisis spread globally, it depressed not only the financial market, but also the construction business in Korea. In fact, according to CERIK, the BSI of the construction businesses plunged from 80 points in December 2006 to 14.6 points in November 2008, and the extent of the depression in the housing sector was particularly serious. In this respect, this paper analyzes the influence of the financial market fluctuation on the housing market before and after the Global Financial Crisis using VECM. The periods from January 2000 to December 2007 and January 2008 to October 2015, before and after the financial crisis, were set as Models 1 and 2, respectively. The results are as follows. First, when the economy is good, the Gangnam housing market is an attractive one for investment. However, when it is depressed, the Gangnam housing market changes in response to the macroeconomic fluctuations. Second, the Gangbuk and Gangnam housing markets showed different responses to fluctuations in the financial market. Third, when the economy is bad, the effect of low interest rates is limited, due to the housing market risk.