• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.421-430
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• 1997

Alveolar bone grows with development of tooth germs and roots; bone deposition occurs with tooth eruption. Bone components undergoes processes of resorption and deposition, and when the balance between them is disrupted, decrease in alveolar bone height or excessive bone deposition result. It has been hon that repositioning of teeth through orthodontic treatment can cause alveolar bone resorption which result in decreased alveolar bone height, and there have been many studies to evaluate such effects. X-ray films that could be replicated and standardized were chosen in clinical studies, and among them, bitewing films were used for objective evaluation of changes in alveolar bone level. Twenty subjects, 10 to 13-year- old (average 12.2) children with Cl I molar key, healthy oral condition, no congenital missing, no periodontal disease, and pre-and post-orthodontic bitewing films, were randomly selected for comparison of alveolar bone heights. Amounts of tooth and changes in alveolar bone heights were analyzed. The following results were obtained: 1. Amount of tooth movement in canine, premolar, and molar regions, changes in tooth axis, and changes in alveolar bone heights were measured, and the mean and median values were obtained. 2. When pre-and post-orthodontic alveolar bone levels were compared, larger changes were noticed in maxilla than mandible. 3. When mesio-distally compared, larger changes were observed in the distal sides of 3D3 and 4M3, mesial sides of 4M3 and 4D3, distal sides of 4D3 and 5M3, mesial sides of 5M3 and 5D3, md distal sides of 5D3 and 6M3. 4. When the amounts of tooth movements(TX, TY)and changes in tooth axis(A) were compared,34TX, 34TY, 34A of both sides in maxilla were greater, iud changes in alveolar bone level were greater than any other region.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.332-340
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• 2009

In this study, the thermal insulation effectiveness of the greenhouse insulators by the installation methods was investigated to find the right installation way of the insulation materials. Physical properties of the insulators such as thickness, air transmissivity, apparent density, ultraviolet rays cutoff ratio, reflectance, thermal conductivity, moisture absorptivity were evaluated and the insulation ability of the insulators were measured by the module experiments. For the same insulator, the insulation ability of the case with the outward direction of the black colored face, i.e., with the inward direction of the white colored face, was better than that of vice versa. The case of the black colored both surfaces was better than the case of the white colored both surfaces. For aluminium reflection material, the case with the outward direction of the lustre face, i.e., with the inward direction of the non-lustre face, was better than that of vice versa. For the same material with the inner thin polyethylene foam (or polyester) and the chemical wool, the case with the outward direction of the inner thin polyethylene foam (or polyester), i.e., with the inward chemical wool, was better than that of vice versa. Addition of the inner thin polyethylene foam increased the insulation effect very much.

• Journal of Intelligence and Information Systems
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• v.19 no.3
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• pp.1-23
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• 2013

To discover significant social issues such as unemployment, economy crisis, social welfare etc. that are urgent issues to be solved in a modern society, in the existing approach, researchers usually collect opinions from professional experts and scholars through either online or offline surveys. However, such a method does not seem to be effective from time to time. As usual, due to the problem of expense, a large number of survey replies are seldom gathered. In some cases, it is also hard to find out professional persons dealing with specific social issues. Thus, the sample set is often small and may have some bias. Furthermore, regarding a social issue, several experts may make totally different conclusions because each expert has his subjective point of view and different background. In this case, it is considerably hard to figure out what current social issues are and which social issues are really important. To surmount the shortcomings of the current approach, in this paper, we develop a prototype system that semi-automatically detects social issue keywords representing social issues and problems from about 1.3 million news articles issued by about 10 major domestic presses in Korea from June 2009 until July 2012. Our proposed system consists of (1) collecting and extracting texts from the collected news articles, (2) identifying only news articles related to social issues, (3) analyzing the lexical items of Korean sentences, (4) finding a set of topics regarding social keywords over time based on probabilistic topic modeling, (5) matching relevant paragraphs to a given topic, and (6) visualizing social keywords for easy understanding. In particular, we propose a novel matching algorithm relying on generative models. The goal of our proposed matching algorithm is to best match paragraphs to each topic. Technically, using a topic model such as Latent Dirichlet Allocation (LDA), we can obtain a set of topics, each of which has relevant terms and their probability values. In our problem, given a set of text documents (e.g., news articles), LDA shows a set of topic clusters, and then each topic cluster is labeled by human annotators, where each topic label stands for a social keyword. For example, suppose there is a topic (e.g., Topic1 = {(unemployment, 0.4), (layoff, 0.3), (business, 0.3)}) and then a human annotator labels "Unemployment Problem" on Topic1. In this example, it is non-trivial to understand what happened to the unemployment problem in our society. In other words, taking a look at only social keywords, we have no idea of the detailed events occurring in our society. To tackle this matter, we develop the matching algorithm that computes the probability value of a paragraph given a topic, relying on (i) topic terms and (ii) their probability values. For instance, given a set of text documents, we segment each text document to paragraphs. In the meantime, using LDA, we can extract a set of topics from the text documents. Based on our matching process, each paragraph is assigned to a topic, indicating that the paragraph best matches the topic. Finally, each topic has several best matched paragraphs. Furthermore, assuming there are a topic (e.g., Unemployment Problem) and the best matched paragraph (e.g., Up to 300 workers lost their jobs in XXX company at Seoul). In this case, we can grasp the detailed information of the social keyword such as "300 workers", "unemployment", "XXX company", and "Seoul". In addition, our system visualizes social keywords over time. Therefore, through our matching process and keyword visualization, most researchers will be able to detect social issues easily and quickly. Through this prototype system, we have detected various social issues appearing in our society and also showed effectiveness of our proposed methods according to our experimental results. Note that you can also use our proof-of-concept system in http://dslab.snu.ac.kr/demo.html.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.3
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• pp.195-207
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• 2000

Organic and inorganic characteristics including bacterial cell number, enzyme activity, nutrients, and heavy metals have been monitored in twelve acrylic experimental tanks for two weeks to estimate and compare self-purification capacities in two Korean wet-land environments, tidal flat and rice field, which are possibly different with the environments in other countries because of their own climatic conditions. FW tanks, filled with rice field soils and fresh water, consist of FW1&2 (with paddy), FW3&4 (without paddy), and FW5&6 (newly reclaimed, without paddy). SW tanks, filled with tidal flat sediments and salt water, are SW1&2 (with anoxic silty mud), SW3&4 (anoxic mud), and SW5&6 (suboxic mud). Contaminated solution, which is formulated with the salts of Cu, Cd, As, Cr, Pb, Hg, and glucose+glutamic acid, was spiked into the supernatent waters in the tanks. Nitrate concentrations in supernatent waters as well as bacterial cell numbers and enzyme activities of soils in the FW tanks (except FW5&6) are clearly higher than those in the SW tanks. Phosphate concentrations in the SW1 tank increase highly with time compared to those in the other SW tanks. Removal rates of Cu, Cd, and As in supematent waters of the FW5&6 tanks are most slow in the FW tanks, while the rates in SW1&2 are most fast in the SW tanks. The rate for Pb in the SW1&2 tanks is most fast in the SW tanks, and the rate for Hg in the FW5&6 tanks is most slow in the FW tanks. Cr concentrations decrease generally with time in the FW tanks. In the SW tanks, however, the Cr concentrations decrease rapidly at first, then increase, and then remain nearly constant. These results imply that labile organic materials are depleted in the FW5&6 tanks compared to the FW1&2 and FW3&4 tanks. Removal of Cu, Cd, As from the supernatent waters as well as slow removal rates of the elements (including Hg) are likely due to the combining of the elements with organic ligands on the suspended particles and subsequent removal to the bottom sediments. Fast removal rates of the metal ions (Cu, Cd, As) and rapid increase of phosphate concentrations in the SW1&2 tanks are possibly due to the relatively porous anoxic sediments in the SW1&2 tanks compared to those in the SW3&4 tanks, efficient supply of phosphate and hydrogen sulfide ions in pore wates to the upper water body, complexing of the metal ions with the sulfide ions, and subsequent removal to the bottom sediments. Organic materials on the particles and sulfide ions from the pore waters are the major factors constraining the behaviors of organic/inorganic elements in the supernatent waters of the experimental tanks. This study needs more consideration on more diverse organic and inorganic elements and experimental conditions such as tidal action, temperature variation, activities of benthic animals, etc.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.1017-1024
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• 2005

This study was investigated the effect of the length of stunning time on pH, water holding capacity(WHC), cooking loss(CL), meat color and incidence rate of blood spot in broiler carcass. One-hundred and forty broiler chickens were slaughtered by three different length of stunning times(5 sec., 8 sec., 11 sec.) with the same electrical frequency(255Hz) and 50 voltage in a commercial abattoir. The WBS values and cooking loss of breast muscle were increased with increasing the stunning time, while WHC of breast muscle were decreased. Lightness(L* value) and yellowness(b* value) scores of leg muscle and skin stunned with 50V, 255Hz, 8 sec, 11 sec. were higher than those of broilers stunned with 50V, 255Hz, 5sec(P<0.05). But, there was no significant difference in color on breast and wing muscle. In subjective evaluation, frequence of the first grade had a trend of being increased by extending the stunning time. There was only a few cases of PSE chicken with 0.02%, while blood spot was observed at the highest rate for the 5 sec. treatment. TBARS indicated that a longer length of stunning resulted in a higher rate of fat oxidation. This experiment demonstrated that the length of stunning time has a significant effect on meat quality and its stability during chiller storage.

• Journal of the Korean earth science society
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• v.36 no.2
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• pp.139-157
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• 2015

We investigated the relative errors of satellite-observed Surface Skin Temperature (SST) data caused by sea ice in the northern hemispheric ocean ($30-90^{\circ}N$) during April 16-24, 2003-2014 by intercomparing MODerate Resolution Imaging Spectroradiometer (MODIS) Ice Surface Temperature (IST) data with two types of Atmospheric Infrared Sounder (AIRS) SST data including one with the AIRS/Advanced Microwave Sounding Unit-A (AMSU) and the other with 'AIRS only'. The MODIS temperatures, compared to the AIRS/AMSU, were systematically up to ~1.6 K high near the sea ice boundaries but up to ~2 K low in the sea ice regions. The main reason of the difference of skin temperatures is that the MODIS algorithm used infrared channels for the sea ice detection (i.e., surface classification), while microwave channels were additionally utilized in the AIRS/AMSU. The 'AIRS only' algorithm has been developed from NASA's Goddard Space Flight Center (NASA/GSFC) to prepare for the degradation of AMSU-A by revising part of the AIRS/AMSU algorithm. The SST of 'AIRS only' compared to AIRS/AMSU showed a bias of 0.13 K with RMSE of 0.55 K over the $30-90^{\circ}N$ region. The difference between AIRS/AMSU and 'AIRS only' was larger over the sea ice boundary than in other regions because the 'AIRS only' algorithm utilized the GCM temperature product (NOAA Global Forecast System) over seasonally-varying frozen oceans instead of the AMSU microwave data. Three kinds of the skin temperatures consistently showed significant warming trends ($0.23-0.28Kyr^{-1}$) in the latitude band of $70-80^{\circ}N$. The systematic disagreement among the skin temperatures could affect the discrepancies of their trends in the same direction of either warming or cooling.

• Journal of Animal Science and Technology
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• v.45 no.2
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• pp.283-296
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• 2003

Emulsion-type sausages were manufactured to investigate the effects of CLA-vegetable oils and CLA-lard on quality characteristics of emulsion-type sausage. Each treatments replaced pork back fat with CLA-corn oil (CLA-CO), CLA-safflower seed oil (CLA-SSO) and CLA-lard (CLA-LD) were stored during 1, 7, 14, 21 and 28 days at 4$^{\circ}C$. The changes in physico-chemical properties, texture, thiobarbituric acid reactive substances (TBARS), fatty acid composition and CLA content of each treatments were measured during 1, 7, 14, 21 and 28 days at 4$^{\circ}C$. During storage, pH of control showed higher pH value than that of CLA-vegetable and CLA-lard treatments. The pH values of all treatments was significantly low at storage 14 days (p<0.05). The color L* and a*-value of all the treatments was not significantly changed with the storage periods. Color b*-value of CLA-treatments was higher than that of control during the storage period. Fatty acids composition was changed by addition of CLA-vegetable oils and CLA-lard. All kinds of fatty acids composition were decreased with CLA replacements than that of the control. Whereas linolenic acid content extremely increased by replacement of CLA-vegetable. CLA content of CLA-treatments was extremely increased than that of the control. The cohesiveness, springness, gumminess and brittleness of CLA-LD treatment was significantly higher (P<0.05) than that of the other treatments. The TBARS value of all treatments were significantly increased (P<0.05) as the storage period was passed. TBARS of sausage products containing CLA-CO was the lowest. Summing up the a forementioned results, emulsion-type sausage manufacturing with CLA-vegetable oil and CLA-lard was not affected in physico-chemical properties and texture characteristics. Also, it may be assumed that the high quality sausage can be manufactured with the extent of storage period and CLA accumulation.

• Korean Journal of Poultry Science
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• v.32 no.3
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• pp.187-193
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• 2005

This study was carried out to investigate the effect of the bleeding times(30sec., 90sec., 150sec.) at slaughtering process on meat quality and storage properties of broiler. The redness$(a^{\ast}\;value)$ of skin, wing, leg muscle decreased at high bleeding time(150sec.). However, there was no significant difference in breast muscle. WHC(water holding capacity) of breast muscle decreased from $63.64\%$ at low bleeding time(30sec.) to $61.06\%$ at high bleeding time. TBARS(thiobarbituric acid-reactive substance) values were 0.18 mgMA/kg at the low bleeding time, 0.16 mgMA/kg at the middle bleeding time(90sec.) and 0.21mgMA/kg high bleeding time on 3 days of storage. Total aerobic plate counts(TPC) were $6.25logCFU/cm^2$ at the low bleeding time, $6.25logCFU/cm^2$ at the middle bleeding time and $6.53logCFU/cm^2$ at the high bleeding time. The TPC was increased as the bleeding time increased. In conclusion, meat color of chicken were acceptable when the carcasses were slaughtered at the high bleeding time.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.821-832
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• 2004

A total of 80 pigs were used to investigate the effect of dietary glycine betaine(N,N,N-trimethylglycine) on pork quality during cold storage. About 70 kg pigs were randomly a1loted into one of four experimental diet groups(0%, 0.2%, 0.4% and 0.6% glycine betaine). Pigs were slaughtered at approximately 110 kg live weight, and pH, color(CIE $L^* a^* b^*$), shear force, sarcomere length, lipid oxidation and composition of fatty acid were measured in pork loin for 13 days of cold storage. The concentration of glycine betaine in pork loin was significantly increased(P<0.05) with increasing of glycine betaine level in diet. Pork loins from dietary betaine groups showed significantly higher muscle pH and lower CIE $b^*$ values compared to control group after 13 days of storage. There were significant differences in shear force values among pork loins from diet groups at 24 hrs postmortem. However, pork loins from control diet showed longer sarcomere length than those of dietary betaine groups. Dietary glycine betaine increased the ratio of saturated fatty acids and decreased unsaturated fatty acids in pork loins. Especially the ratios of linoleic and myristic acid were decreased with increasing dietary betaine level. However, dietary glycine betaine did not affect lipid oxidation (TSARS) and sensory evaluation during cold storage.

• Journal of the Korean Applied Science and Technology
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• v.36 no.2
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• pp.656-667
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• 2019

This study is a descriptive research to grasp the effects of job stress on turnover intention and to confirm the mediating effect of organizational commitment according to the extent of job stress, organizational commitment and turnover intention in the relations between job stress and Turnover Intention of nurses working in general hospitals. Method: The subjects of this study were 199 nurses are working in general hospitals, that have more than 200 beds and less than 400 beds, located in Gwangju. I surveyed them using a structured questionnaire for collecting data from Sep. 01, 2017 to Sep. 20, 2017. The collected data were analyzed by the frequency, the percentage, t-test, ANOVA, Scheffe's Test, Pearson's Correlation Coefficient, Multiple Regression Analysis and Sobel Results: In the first step, job stress as an independent variable had a statistically significant effect on organizational commitment(${\beta}=-.321$, p<.001). In the second step, job stress, an independent variable, also had an important effect on turnover intention as a dependent variable(${\beta}=.389$, p<.001). Job stress and organizational commitment were meaningful predictor variables of turnover intention in the third step. The explanatory power of two variables was 45.5%. The value ${\beta}$ of job stress in the third step was .203(p<.001) which was smaller than its value ${\beta}$,.389(p<.001), in the second step. That meant organizational commitment had the mediating effect on turnover intention. The Sobel Test was conducted to verify the significance of the extent of the mediating effects of organizational commitment. The test result was that the value Z was -3.694 and the mediating effect of organizational commitment was significant on the relation between job stress and turnover intention(p<.002). Conclusion: this study is expected be useful to find ways to reduce subjects' turnover intention by decreasing their job stress, increasing their organizational commitment and developing intervention programs as basic data.