• Korean Journal of Soil Science and Fertilizer
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• v.14 no.4
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• pp.230-235
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• 1982

This study was carried out to select the most effective extractant for Cd analysis in the condition of Korean paddy soil. The various extractants were compared with 0.1 N-HCL common extractant used in Korea. Soil and rice samples were collected at same plot from paddy field adjacent to zinc mining sites. The results ob.tained are as follows. 1. The extractants were able to be arranged in order of higher extractability of cadmium content; 1N-HCL > 0.1N-HCL > 0.075N-Mixture > $1N-NH_4OAC(pH4.8)$ > $DTPA-CaCl_2$ > 5% Acetic acid> $1N-NH_4OAC(pH7.0)$ > $1N-NH_4NO_3$. 2. Although all extractants showed highly significant correlation between Cd content in soil and that in brown rice, $1N-NH_4OAC(pH7.0)$ was considered to be best. 3. The relationship between Cd concentration in soil by extractants and that in brown rice was varied depending on the levels of total Cd content and soil texture. 4. The best extractant under the soil corntions such as total Cd contents and soil texture believed to be $1N-NH_4OAC(pH7.0)$ but Cd concentration extracted in soil was low. 5. The extractant of 0.075N-Mixture was found to be a recommendable one, because it was simillar to 0.1N-HCL in extracting capacity and showed the better correlation between Cd content in soil and brown rice compared to the latter.

• Journal of Animal Science and Technology
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• v.53 no.2
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• pp.89-97
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• 2011

In this study, the efficiency of microsatellite (MS) markers for pork quality was examined and further, their suitability to domestic pork industry also was verified, by measuring meat quality parameters of Berkshire breeds. A total of 323 pigs of Berkshire breeds were slaughtered and subjected to meat quality evaluation. In addition, the genomic DNAs from blood samples of slaughtered pigs were used for genotyping analysis of 50 MS markers. The results revealed that Berkshire breeds have excellent meat quality, compared with the popular domestic breeds such as Duroc, Yorkshire, and Landrace. Noticeably, the Berkshire breeds exhibited a significant post-mortem pH24hr ($5.88{\pm}0.01$) and fat content ($2.878{\pm}0.06$). Through the linkage analysis between MS markers, 14 MS markers showed significant association with meat quality traits (p<0.05). Maximum significant differences of 0.55 pH24hr value and 2.04% fat content were observed between the highest and lowest allele populations. If these 14 MS markers are applied to the pork quality diagnosis kit, the synergistic effect can be expected in meat quality parameters such as meat color, fat content, pH 24 hr, cooking loss, drip loss and water-holding capacity.

• The Korean Journal of Mycology
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• v.39 no.3
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• pp.164-170
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• 2011

Amanita hemibapha is a kind of mycorrhizal mushroom which has a relation with host plants and environmental factors. For the purpose of studying the relationship between environmental factors and mushrooms, in this study we conducted to investigate the soil physicochemical properties, the distribution of plants and the diversity of mushrooms in Gwangyang, Chungdo and Daegu. Soil texture in habitate of Amanita hemibapha was Sandy Loam and Sandy Clay Loam which contains a high rate of sand. Soil pH was approximately 5.0 in all study sites. Total nitrogen contents, C/N ratio and available phosphate($P_2O_5$) were the highest at the Chungdo. However, Gwangyang and Chungdo represent similar Cation Exchange Capacity(C.E.C) and Daegu has much less than other areas. Exchangeable cations, $Ca^{2+}$ content was higher at Gwangyang and Chungdo than Daegu and $Na^+$ content was the highest at Chungdo among three sites. Daegu has much $Mg^{2+}$ contents followed by Chungdo and Gwangyang. Interestingly, $K^+$ content listed in reverse order of $Mg^{2+}$ at Gwangyang, Chungdo and Daegu. The main woody plants in study sites are confirmed as Carpinus laxiflora, Quercus mongolica, Q. serrata and Pinus densiflora. Quercus species are found as a common species in three study sites. Lastly, 8 family and 12 species of mushrooms are emerged in Gwangyang, also 8 family and 12 species and 5 family and 10 species are found in Chungdo and Daegu, respectively. Amanita pantherina, Boletus edulis, Tylopilus felleus and Marasmius maximus, which found in study sites, are also kind of mycorrhizal mushroom same as A. hemibaph. By using correspondence analysis, Q. mongolica, Q. serrata, Q. variabilis and C. laxiflora are expected to as a host plant of A. hemibapha.

• Journal of Korean Society of Forest Science
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• v.35 no.1
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• pp.1-8
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• 1977

Forest soil fertility was evaluated through the approach of numerical method. In this study, the soil chemical properties analyzed for 35 different soil series as table 2 were cited in numerical analysis. Minimum contents of essential nutrients in the surface soil for a satisfactory growth of tree in the plantation were evaluated by comparing with Wild's standard as table 1. Demanding level of fertilization were evaluated by using the formula 1 as table 5. Similar relation of soil chemical properties between soil series were calculated through formula 2, and then classified into 5 groups in soil chemical properties. 1. General chemical properties of surface soil in case of 35 soil series. About 40 percent of 35 different soil series are less than 2 percent in organic matter, 10 ppm in available phosphorus, 1.25m.e/l00g in exchangeable calcium and 0.5m.e/l00g in exchangeable magnesium. Generally, shortage of exchangeable potash are not found. CEC less than 10m.e/l00g are in two thirds and strong acid soil less than PH 5.5 are in about four fifths. 2. Soil series requested or not the fertilization are indirectly evaluated from the formula 1 using the relative figure of chemical components of CEC, OM and MgO. Through this analysis, 8 different soil series have very poor quality in soil chemical capacity so that demands highly the fertilization. On the other hand, other 13 different soil series group have not been thought to need the fertilization according to chemical guality. 3. By the results comparing the similarity of chemical properties of forest soil, it is thought to be suitable that the forest soil fertility are divided into 5 groups as follows: 1. Low CEC soil 1-1 Low organic matter soil less than 2 percent 1-2 Medium organic matter soil less than 4 percent 2. High CEC and organic matter soil 2-1 Low magnesium soil 2-2 High magnesium soil 3. High magnesium and calcium soil as lime stone.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.207-220
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• 2006

The newly developed equipments for the early detection of carious lesion are LFD (laser fluorescence device), Ultrasonic diagnostic system, CLSM(confocal laser scanning microscopy), QLF(quantitative light-induced fluorescence) and DIFOTI (digital imaging fiber-optic trans-illumination) system. In this study, DIFOTI system and LFD were used for the detection of early enamel caries. Twenty five primary teeth extracted from twenty one children at around the dentitional exchanging period were selected as samples. The results obtained from DIFOTI imaging and LFD measurement were compared with those of CLSM and comprehensive evaluations were made for the diagnostic capacity of each device. In vitro test, 40 sample teeth with their buccal & lingual surface formed by a window of $2{\times}3mm$ in diameter were immersed in artificial demineralizing solution for the period of 4, 8, 12 and 16 days. The results obtained from the experimental groups (DIFOTI, LFD) were compared to control group (CLSM) and we have reached to the following conclusions. 1. The sensitivity and specificity of DIFOTI system operated in oral environment was 88.2% and 76.9% respectively. 2. The sensitivity and specificity of LFD measured in oral environment was 76.5% and 69.2% respectively. 3, Regression analysis on the light transparent rate of DIFOTI showed its decrease according to the length of primary enamel decalcification performed in vitro(r=-0.96, p<0.05). 4. No statistically significant difference between LFT measurement and the length of in vitro decalcification was found in regression analysis (p>0.05). 5. The correlation coefficient of DIFOTI image transparent rate and the lesion depth of CLMS was -0.6988 (p<0.05), whereas no statistically significant difference was found for LFD measurement.

• Tuberculosis and Respiratory Diseases
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• v.48 no.6
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• pp.944-955
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• 2000

Background : In patients with chronic obstructive pulmonary disease(COPD), several factors have been associated with a poor prognosis. These include old age, low $FEV_1$ low diffusing capacity, high alveolar-arterial oxygen pressure difference, and finally cor pulmonale. This study was done to investigate if the ECG signs suggesting cor pulmonale were independent prognostic factors in patients with COPD. Method : We analyzed ECG, pulmonary function data and arterial blood gas values in 61 patients who were admitted through the emergency department with an acute exacerbation of COPD. The ECG signs reflecting cor pulmonale were right strial overloading(RAO), right bundle branch block, right ventricular hypertrophy and low-voltage QRS. The 61 patients were divided into 2 groups ; group I with no ECG signs(n=36) and group II with one or more ECG signs(n=25) suggesting cor, pulmonale. Results : Poor, prognostic factors by univariate analysis were low $FEV_1$, $FEV_1$ % pred., VC % pred., DLco, DLco % pred., $PaO_2$ and $SaO_2$ high $PaCO_2$ presence of ECG signs reflecting cor pulmonale, presence of mental status change, use of mechanical ventilator, and long term use of glucocorticoid. A multivariate analysis indicated that age(risk ratio=1.13, 95% confidence interval 1.05-1.23), DLco % pred. (risk ratio=0,97. 95% confidence interval 0.94-0.99), $PaO_2$ (risk ratio=0.95, 95% confidence interval 0.90-0.99) and RAO(risk ratio=5.27, 95% confidence interval 1.40-19.85) were independent prognostic factors of survival. There was a significant difference in survival between the patients with and without RAO(p=0.038). The survival rates at 1, 2, and 5 years were 94.5%. 81.4%, and 50.0% in patients without RAO and 82.4%, 70.6%, and 27.5% in patients with RAO, respectively. Conclusion : These results suggest that the presence of ECG signs reflecting cor pulmonale is a predictor of survival and that RAO of these ECG signs is a significant independent predictor of survival in patients with COPD.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.746-753
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• 1998

Background : Cigarette smoking is closely related to both lung cancer and chronic obstructive pulmonary disease. The incidence of lung cancer is higher in patients with obstructive ventilatory impairment than in patients without obstructive ventilatory impairment regardless of smoking. So, obstructive ventilatory impairment is suspected as an independent risk factor of lung cancer. Methods: For the evaluation of the role of obstructive ventilatory impairment as a risk factor of lung cancer, a total of 73 cases comprising 47 cases of malignant and 26 benign solitary pulmonary nodule were analyzed retrospectively. A comparative study of analysis of forced expiratory volume curves and frequencies of obstructive ventilatory impairment were made between cases with malignant and benign nodules. Results: In comparison of vital capacity and parameters derived from forced expiratory volume curve between two groups. VC, FVC and $FEV_1$ were not significantly different. whereas $FEV_1/FVC%$ and FEF 25-75% showed a significant decrease in the cases with malignant nodule. The frequency of obstructive ventilatory impairment determined by pulmonary function test was significantly higher in the cases with malignant nodule(23.4%) than in benign nodule(3.8%). When the risk for lung cancer was examined by the presence or absence of obstructive ventilatory impairment using the logistic regression analysis, the unadjusted relative risk for the lung cancer of obstructive ventilatory impairment was 17.17. When the effect of smoking and age were considered, the relative risk was to 8.13. Conclusion: These findings suggest that an obstructive ventilatory impairment is a risk factor of lung cancer.

• Tuberculosis and Respiratory Diseases
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• v.72 no.1
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• pp.8-14
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• 2012

Background: Although airway obstruction in chronic obstructive pulmonary disease (COPD) is due to pathologic processes in both the airways and the lung parenchyma, the contribution of these processes, as well as other factors, have not yet been evaluated quantitatively. We therefore quantitatively evaluated the factors contributing to airflow limitation in patients with COPD. Methods: The 213 COPD patients were aged >45 years, had smoked >10 pack-years of cigarettes, and had a post-bronchodilator forced expiratory volume in one second ($FEV_1$)/forced vital capacity (FVC) <0.7. All patients were evaluated by medical interviews, physical examination, spirometry, bronchodilator reversibility tests, lung volume, and 6-minute walk tests. In addition, volumetric computed tomography (CT) was performed to evaluate airway wall thickness, emphysema severity, and mean lung density ratio at full expiration and inspiration. Multiple linear regression analysis was performed to identify the variables independently associated with $FEV_1$ - the index of the severity of airflow limitation. Results: Multiple linear regression analysis showed that CT measurements of mean lung density ratio (standardized coefficient ${\beta}$=-0.46; p<0.001), emphysema severity (volume fraction of the lung less than -950 HU at full inspiration; ${\beta}$=-0.24; p<0.001), and airway wall thickness (mean wall area %; ${\beta}$=-0.19, p=0.001), as well as current smoking status (${\beta}$=-0.14; p=0.009) were independent contributors to $FEV_1$. Conclusion: Mean lung density ratio, emphysema severity, and airway wall thickness evaluated by volumetric CT and smoking status could independently contribute to the severity of airflow limitation in patients with COPD.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.1
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• pp.39-48
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• 2010

Recreation forests are in the spotlight as the place for personality development, mind and body comfort, companionship, and environment education in forests and valleys. Visitors to recreation forests have been on the increase along with booming in recreation forest building since 1988. Recreation forests are being categorized according to some features such as regional and environmental condition. Recreation forests, however, have not met the expectations of some visitors who want to take a rest with calmness due to the influence of the 5-day-work-week system, increasing interest in rest, leisure, and well-being, and users converge during weekends, summer, and the tourist season. In order to improve visitors' satisfaction efficiently, this study surveyed the level of satisfaction in each cluster based on the precedent study which had classified 85 national or public recreation forests in Korea into clusters. Questionnaires were distributed properly to each cluster and, of the 1,132 questionnaires collected, 1,015 were valid and used for analysis. Reliability of questionnaires and statistical validity of the model were verified. As a result, there are meaningful differences in the ranking of independent variables which affect the level of satisfaction according to clusters. Variables in rest and fatigue recovery have the strongest influence on the level of satisfaction in the clusters of potential factor, internal activation factor, and mixed potential capacity factor. In the use performance and visiting condition factor cluster, appropriateness of visit cost is most influential and, in the education cluster, connectivity with tourist attractions around it is most affective. These results can provide priority in services and maintenance of recreation forests for improving the level of satisfaction and differentiate the distribution of resources according to clusters.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.2
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• pp.129-153
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• 2017

Fair Competition policy in aviation field has been discussed since open skies policy began in 1970s. This issue has been also the main topic in the ICAO's Worldwide Air Transport Conference, the Air Transport Symposium, etc. ICAO defines competition as the existent or potential rivalry between two or more operators, carriers or groups, striving for advantages in the same market based on different prices, qualities and services. In a broader sense, the definition includes more various meanings; reasonable, fair, effective, and unrestricted competitions. Nowadays, competition laws and regulations to air transportation have been applied more frequently and the issues varies from antitrust immunity, mergers and alliances, abuse of dominant positions, capacity dumping and predatory pricing, sales and marketing, to airport charges and fees, state aid and loan guarantees. Now, the competition among the airlines or nations in aviation industry is changing to cooperation level. A lot of airlines try to survive by various cooperation methods. Therefore the policy of Korean aviation industry should be developed, taking so-called "the viewpoint of national aviation industry ecosystem" into consideration and Korean government should prepare a policy of fair competition to cope with it. First, in the process of open skies policy with neighboring countries such as China, Japan and the Middle East, it is necessary to apply the fair competition act and prepare laws and regulations to implement it. Second, the standards of effective ownership and control of air transportation business should be reviewed. Third, in preparation for aviation agreements and liberalization, the Korean aviation industry needs to study and review competition and cooperation issues through the analysis of strict aviation market structure for airlines and airport operations. Fourth, it is necessary to create a fair air transportation environment for the development of air transportation and competitiveness through preemptive policies such as the approval of mergers, acquisitions, JV and the ripple effects analysis.