• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.355-373
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• 1995

Craniofacial region is a musculodentoskeletal system that consists of many anatomical structures ; cranioskeletal structures, dental arches, and formation and functions of masticatory muscles have close correlations. Growth and development of craniofacial region are influenced by not only hereditory factors, but also environmental factors such as craniofacial muscles and surrounding tissues. On the contrary, however, study on changes in functions or adaptations of craniofacial muscles following changes of craniofacial skeletal structures has been somewhat insufficient. The author's purpose was to observe correlations between masticatory muscular functions and change patterns according to cranial skeletal structures and occlusion patterns, for this, comparative study of muscle activity changes of preand post- orthognathic surgery states in skeletal Cl III malocclusion patients was peformed. The selected sample groups were 15 normal male patients, 15 skeletal Cl III pre-orthognatic surgery patients and 15 skeletal Cl III post-orthognatic surgery patients. For each sample groups, cephalometric x-ray taking, masticatory efficiency test and measurements of muscle activities in anterior temporal muscle, masseter and upper lip in rest, clenching, chewing and swallowing were carried out. The following results were obtained : 1. In resting state of mandible, pre-surgery malocclusion group showed higher m. activities in ant. temporalis, masseter and upper lip than post-surgery group. Post-surg. malocc. group showed significantly high m. activity only in upper lip compared to the normal group. 2. In clenching state, post-surg. malocc. group showed higher m. activities in ut. temporalis, masseter and upper lip than pre-surg. malocc. group. 3. In chewing state, post-surg. malocc. group showed higher m. activities in ant. temporalis and masseter than pre-surg. malocc. group, on the other hand, decreased upper lip activity was noticed. 4. In swallowing state, post-surg. malocc. group showed lower upper lip activity than pre-surg. malocc. group but higher than that of the normal group. No significant difference in m. activities of ant, temporalis and masseter was noticed among the three groups. 5. Masticatory efficiency was lower in pre-surg. malocc. group than normal group, masticatory efficiency showed an increase in post-surg. malocc. group compared to the pre-surg. malocc. group. However, both groups showed significant differences compared to the normal group.

• Journal of Preventive Medicine and Public Health
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• v.20 no.1 s.21
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• pp.10-39
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• 1987

Mortality rate and causes of death are regarded as an index of strength as well as level of development of a country. However, there is no accurate data for the causes of death in Korea due to lack of systematic vital data collection system. The objective of this study was to define the causes of death of the school teachers, its changing pattern, cause-specific mortality rate, and geographic variation. The study population included all of the teachers in primary school, middle and high schools, and college who joined in Korean Teachers' Union between 1968 and 1985 that provided a total of 1,972, 069 person-years to observe (1,384,911 man-years, 587,158 woman-years). There were 3,678 deaths in this period (3,377 males, 301 females). The most common cause of death was neoplasm which was followed by the diseases of circulatory system. The proportion of death of neoplasm was 1.5 times higher than that of the general population. Causes of death were classified into 5 major groups (neoplasm, diseases of circulatory system, accidents and poisoning, diseases of liver, and all others). The mortality rates of diseases of circulatory system and all others for general population were 4 to S times higher than those for the teachers. However, mortality rates of neoplasm and diseases of liver were only about 2 times higher than those for teachers. Mortality rate of liver cancer for teachers was higher than gastric cancer mortality rate which is the reverse in general population. The crude death rate was 2.12 per 1,000 person-years for male and 1.00 for female which is one-third of the crude death rate of general population. Crude death rate of study population was higher in rural area than in urban area. However, mortality rate of neoplasm for male was higher in urban area than in rural area while mortality rates of all other causes were higher in rural area. For female, mortality rates of neoplasm and diseases of circulatory system were higher in urban area and the rates for all other causes were higher in rural area. Crude death rate was lowest in Gyeongin area and highest in Yeongnam area. The mortality of neoplasm for male accounted the highest proportion of all death in Gyeongin, Chungcheong and Yeoungnam areas while the mortality of neoplasm and mortality of circulatory system accounted the same proportion in Jeonra area. For female, the mortality of disease of circulatory system accounted the highest proportion in Gyeongin and Yeoungnam and Jeonra areas. Proportion of death due to accidents and poisoning was high in Chungcheong area and death due to all other causes was high in Yeoungnam area. The most common cause of death for male by city and province was neoplasm in Seoul, Busan, Daegu, Gyeonggi, Chungnam, Chungbuk, Gyeongnam and Gyeongbuk. Diseases of circulatory system was the leading cause of death in the rest of city and provinces. The leading cause of death for female was diseases of circulatory system in Seoul, Incheon, Chungbuk, Chungnam, and Gyeongbuk, neoplasm in Busan, and accident and poisons in all other cities and provinces. The mortality rates of male were above 2 per 1,000 person-years in Jeju, Gyeongbuk, Gyeongnam, Daegu, and Chungbuk, and it was below 1.5/l,000 in Seoul, Incheon and Gyeonggi. The mortality rate of female was above 1.2/1,000 person-years in Gyeongnam and Incheon while it was below 0.5/l,000 in Daegu, Geonggi Chungbuk and Jeju. The leading cause for male by school of employment was neoplasm in all levels of school with a remarkably higher rate in the professors of college. Leading cause of death for female was disease of circulatory system in primary schools, high schools and college but neoplasm in middle schools. There was no death due to liver diseases in middle and high school teachers and college professors and no death due to all other category in high school teachers and college professors, in females. High school teachers and the highest mortality rate and college professors showed the lowest mortality rate. Temporal trend of mortality was examined in three periods; period I ($1968{\sim}1974$), period II ($1975{\sim}1979$), and period III ($1980{\sim}1985$). The leading cause of death for male was diseases of circulatory system in period I and II but neoplasm in period III. Such trend of decreasing diseases of circulatory system and increasing neoplasm was observed in female. Overall mortality rate was decreased over the 3 periods. The mortality rates of diseases of circulatory system, liver disease and all others were decreased in male but the mortality rates of neoplasm and accident and posions was increased. Female showed a similar trend to male but the mortality rate of liver diseases was increased. Mortality rates of diseases of circulatory system, neoplasm and liver diseases increased with age of teachers up to 50 years of age but decreased in 60 years of age. Mean age at death due to each cause was higher in male than female by $4{\sim}10$ years. However, the mean age at death of the teachers was $2{\sim}5$ years lower than that of the general population in all causes of death and the sex difference in the mean a2e at death was smaller ($2{\sim}3$ years) in general population. In sex ratio of mortality, male was higher than female in almost all diseases except suicide and maintained a high ratio. The general population showed universally high ratio in male like teachers, and more or less did regular patterns in mortality with ratio smaller.

• Journal of the Korean earth science society
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• v.32 no.3
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• pp.276-293
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• 2011

In this study a modeling system consisting of Weather Research and Forecasting (WRF), Sparse Matrix Operator Kernel Emissions (SMOKE), the Community Multiscale Air Quality (CMAQ) model, and the CMAQ-Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (MADRID) model has been applied to estimate enhancements of $PM_{10}$ during Asian dust events in Korea. In particular, 5 experimental formulas were applied to the WRF-SMOKE-CMAQ (MADRID) model to estimate Asian dust emissions from source locations for major Asian dust events in China and Mongolia: the US Environmental Protection Agency (EPA) model, the Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model, and the Dust Entrainment and Deposition (DEAD) model, as well as formulas by Park and In (2003), and Wang et al. (2000). According to the weather map, backward trajectory and satellite image analyses, Asian dust is generated by a strong downwind associated with the upper trough from a stagnation wave due to development of the upper jet stream, and transport of Asian dust to Korea shows up behind a surface front related to the cut-off low (known as comma type cloud) in satellite images. In the WRF-SMOKE-CMAQ modeling to estimate the PM10 concentration, Wang et al.'s experimental formula was depicted well in the temporal and spatial distribution of Asian dusts, and the GOCART model was low in mean bias errors and root mean square errors. Also, in the vertical profile analysis of Asian dusts using Wang et al's experimental formula, strong Asian dust with a concentration of more than $800\;{\mu}g/m^3$ for the period of March 31 to April 1, 2007 was transported under the boundary layer (about 1 km high), and weak Asian dust with a concentration of less than $400\;{\mu}g/m^3$ for the period of 16-17 March 2009 was transported above the boundary layer (about 1-3 km high). Furthermore, the difference between the CMAQ model and the CMAQ-MADRID model for the period of March 31 to April 1, 2007, in terms of PM10 concentration, was seen to be large in the East Asia area: the CMAQ-MADRID model showed the concentration to be about $25\;{\mu}g/m^3$ higher than the CMAQ model. In addition, the $PM_{10}$ concentration removed by the cloud liquid phase mechanism within the CMAQ-MADRID model was shown in the maximum $15\;{\mu}g/m^3$ in the Eastern Asia area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.6008-6014
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• 2013

This study aimed to understand seasonal variation of physico-chemical factors and biomass of size-fractionated phytoplankton at Ulsan seaport during the period from February 2007 to November 2009. Water temperature, salinity, dissolved oxygen (DO), pH, chemical oxygen demand (COD) and total suspended solid (TSS) varied in the range of 8.94-$24.26^{\circ}C$, 25.06-34.54 psu, 4.30-10.73 mg/L, 7.97-8.53, 0.66-40.70 mg/L and 57.4-103.3 mg/L, respectively. These factors showed no clear spatial variation unlike spatial pattern of inorganic nutrients and total chlorophyll-a (chl-a) concentration as biomass. Concentration of phosphate, nitrate and silicate ranged from 0.01 to 3.03 ${\mu}M$, 0.05 to 21.62 ${\mu}M$, and 0.01 to 27.82 ${\mu}M$, respectively, with 2 times higher concentration at inner stations than that at outer stations during the study period. Within the range of total chl-a concentration (0.36-7.11 ${\mu}gL^{-1}$), higher concentration (avg. 1.88 ${\mu}gL^{-1}$) of total chl-a were observed at inner stations compared to that (avg. 0.90 ${\mu}gL^{-1}$) at outer stations. Micro-sized phytoplankton dominated total biomass of phytoplankton in spring (34.0-81.2%), summer (35.1-65.6%) and winter (3.9-62.0%). Nano- and pico-sized phytoplankton contributed 58.2-74.5% and 22.4-38.2% to total biomass of phytoplankton in autumn, respectively. However, contribution in biomass of size-fractionated phytoplankton to total phytoplankton biomass showed no clear difference between inner and outer stations. Consequently, these results indicated that spatio-temporal distribution of phytoplankton biomass at Ulsan seaport was dominated by micro-phytoplankton (avg. 52.3%) during the study period except autumn, which was closely dependent on the concentration of inorganic nutrients (p<0.05).

• The Journal of Korean Medicine
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• v.31 no.1
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• pp.81-92
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• 2010

Objectives: The objective of this study was to assess bra in activation and difference by LI11 or ST36 acupuncture stimulation using functional MRI (fMRI). Methods: A total of 10 healthy right-handed volunteers were studied. LI11 acupuncture and ST36 acupuncture stimulations were applied in order on the left. The block design paradigm of RARARA was used for the task, with R representing rest and A representing stimulation, and each period lasted 30 seconds. fMRI data were analyzed using SPM2. Results: The left LI11 acupuncture stimulation activated both sides of the inferior parietal lobule, the left side of the extra-nuclear, culmen and inferior semi-lunar lobules. On the right side, the nodule and midbrain regions were activated by the left LI11 acupuncture stimulation. The left ST36 acupuncture stimulation activated the right side of the superior frontal gyrus, middle frontal gyrus, superior parietal lobule, inferior semi-lunar lobule and pyramis. On the left side, the sub-gyral, middle temporal gyrus, fusiform gyrus, supramarginal gyrus, extra-nuclear, cingulate gyrus and fastigium regions were activated by the left ST36 acupuncture stimulation. Besides, both sides of the paracentral lobule, inferior parietal lobule, culmen, cerebellar tonsil and midbrain regions were activated. Conclusions: In conclusion, brain signal activation patterns according to acupoints were observed to differ, and ST36 acupuncture stimulation activated more regions than LI11. It is supposed that LI11 and ST36 acupuncture stimulations have an influence on motor function and sensory aphasia, and these stimulations thus represent potential for ocular motor dysfunction, discriminative touch or position sense disorder. Moreover, ST36 acupuncture stimulation activated the cingulate gyrus of the limbic system, so it seems to have an influence over autonomic functions.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1551-1558
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• 2002

Purpose : Loss of hippocampal interneurons in dentate gyrus has been reported in patients with severe temporal lobe epilepsy and in animals treated with kainic acid(KA). Interneurons contain $Ca^{2+}$- binding protein parvalbumin(PV). The effects of kainic acid on parvalbumin-immunoreactive (PV-IR) interneurons in dentate gyrus were investigated in organotypic hippocampal slice cultures. Methods : Cultured hippocampal slices from postnatal day nine C57/BL6 mice were exposed to $10{\mu}M$ KA, and were observed at 0, 8, 24, 48, 72 hours after a one hour KA exposure. Neuronal injury was determined by morphologic changes of PV-IR interneuron in dentate gyrus. Results : Transient(1 hour) exposure of hippocampal explant cultures to KA produced marked varicosities in dendrites of PV-IR interneuron in dentate gyrus and the shaft of interbeaded dendrite is often much thinner than those in control. The presence of varicosities in dendrites was reversible with KA washout. The dendrites of KA treated explants were no longer beaded at 8, 24, 48 and 72 hours after KA exposure. The number of cells in PV-IR interneurons in dentate gyrus was decreased at 0, 8 hours after exposure. But there was no significant difference in 24, 48 and 72 hours recovery group compared with control group. Conclusion : The results suggested that loss of PV-IR interneurons in dentate gyrus is transient, and is not accompanied by PV-IR interneuronal cell death.

• Korean Journal of Remote Sensing
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• v.32 no.6
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• pp.733-739
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• 2016

Insolation is an major indicator variable that can serve as an energy source in earth system. It is important to monitor insolation content using remote sensing to evaluate the potential of solar energy. In this study, we performed sensitivity analysis of observed frequency on daily composite insolation over the Korean peninsula. We estimated INS through the channel data of Communication, Ocean and Meteorological Satellite (COMS) and Cloud Mask which have temporal resolution of 1 and 3 hours. We performed Hemispherical Integration by spatial resolution for meaning whole sky. And we performed daily composite insolation. And then we compared the accuracy of estimated COMS insolation data with pyranometer data from 37 points. As a result, there was no great sensitivity in the daily composite INS by observed frequency of satellite that accuracy of the calculated insolation at 1 hour interval was $28.6401W/m^2$ and 3 hours interval was $30.4960W/m^2$. However, there was a great difference in the space distribution of two other INS data by observed frequency of clouds. So, we performed sensitivity analysis with observed frequency of clouds and distinction between the two other INS data. Consequently, there was showed sensitivity up to $19.4392W/m^2$.

• Korean Journal of Ecology and Environment
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• v.48 no.4
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• pp.238-252
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• 2015

The effect of weir construction (2009~2011) was investigated on algal bloom dynamics and surrounding conditions in the Youngsan River by analyzing the long-term (2001~2014) data provided by the Water Information System, Ministry of Environment. The data include chlorophyll a and water properties such as total suspended solids (TSS), ammonium ($NH_4{^+}$), nitrate ($NO_3{^-}$), orthophosphate ($PO{_4}^{3-}$), total nitrogen (TN), total phosphorus (TP) and DIN/DIP molar ratio collected from 12 stations along the channel of the river. Temporal variations were examined using data collected monthly from 2001~2014 and Box-Whisker plot was used to examine the difference in algal bloom dynamics between before (2006~2008) and after (2012~2014) the weir construction. Pearson's correlation analysis was also used to analyze the correlation of parameters. The results showed that TSS affecting water turbidity increased during the construction but decreased especially at the stations located in the upper and middle regions of the river after the construction. Ammonium concentrations increased whereas the concentrations of other nutrients decreased after the construction inducing an increase in N:P molar ratio. Chlorophyll a decreased suddenly during the construction but increased clearly after the construction at the stations where TSS decreased. This indicates that algal blooms can develop in the Youngsan River due to a decrease in turbidity that increases light penetration in water column although the concentrations of nutrients such as orthophosphate were reduced after the weir construction.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.2
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• pp.79-87
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• 2009

Pot experiments using sand culture were conducted in 2004 under greenhouse conditions to evaluate the effect of nitrogen deficiency on red pepper biomass. Nitrogen stress was imposed by implementing 6 levels (40% to 140%) of N in Hoagland's nutrient solution for red pepper. Canopy reflectance measurements were made with hand held spectral sensors including $GreenSeeker^{TM}$, $Crop\;Circle^{TM}$, and $Field\;Scout^{TM}$ Chlorophyll meter, and a spectroradiometer as well as Minolta SPAD-502 chlorophyll meter. Canopy reflectance and dry weight of red pepper were measured at five growth stages, the 30th, 40th, 50th, 80th and 120th day after planting(DAT). Dry weight of red pepper affected by nitrogen stress showed large differences between maximum and minimum values at the 120th DAT ranged from 48.2 to $196.6g\;plant^{-1}$, respectively. Several reflectance indices obtained from $GreenSeeker^{TM}$, $Crop\;Circle^{TM}$ and Spectroradiometer including chlorophyll readings were compared for evaluation of red pepper biomass. The reflectance indices such as rNDVI, aNDVI and gNDVI by the $Crop\;Circle^{TM}$ sensor showed the highest correlation coefficient with dry weight of red pepper at the 40th, 50th, and 80th DAT, respectively. Also these reflectance indices at the same growth station was closely correlated with dry weight, yield, and nitrogen uptake of red pepper at the 120th DAT, especially showing the best correlation coefficient at the 80th DAT. From these result, the aNDVI at the 80th DAT can significantly explain for dry weight of red pepper at the 120th DAT as well as for application level of nitrogen fertilizer. Consequently ground remote sensing as a non-destructive real-time assessment of plant nitrogen status was thought to be a useful tool for in season nitrogen management for red pepper providing both spatial and temporal information.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.303-318
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• 2014

Baseflow gives a significant contribution to stream function in the regions where climatic characteristics are seasonally distinct. In this regard, variable baseflow can make it difficult to maintain a stable water supply, as well as causing disruption to the stream ecosystem. Changes in land use can affect both the direct flow and baseflow of a stream, and consequently, most other components of the hydrologic cycle. Baseflow estimation depends on the observed streamflow in gauge watersheds, but accurate predictions of streamflow through modeling can be useful in determining baseflow data for ungauged watersheds. Accordingly, the objectives of this study are to 1) improve predictions of SWAT by applying the alpha factor estimated using RECESS for calibration; 2) estimate baseflow in an ungauged watershed using the WHAT system; and 3) evaluate the effects of changes in land use on baseflow characteristics. These objectives were implemented in the Gapcheon watershed, as an ungauged watershed in South Korea. The results show that the alpha factor estimated using RECESS in SWAT calibration improves the prediction for streamflow, and, in particular, recessions in the baseflow. Also, the changes in land use in the Gapcheon watershed leads to no significant difference in annual baseflow between comparable periods, regardless of precipitation, but does lead to differences in the seasonal characteristics observed for the temporal distribution of baseflow. Therefore, the Guem River, into which the stream from the Gapcheon watershed flows, requires strategic seasonal variability predictions of baseflow due to changes in land use within the region.