• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.102-105
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• 1999

Mineralization of organic N is an important factor in determining the appropriate rate of organic matter application to paddy fields. A kinetic analysis was conducted for nitrogen mineralization of rice, barley, Chinese milk Ovetch (Astragalus sinicus L.; MV) and narrow leaf vetch straw in paddy soil. Nitrogen immobilization occurred rapidly and its rate increased in straw with high C/N ratio. The amount of nitrogen mineralization was rapid in the first year of rice-vetch cropping system. The rate constant (K) depended on the C/N ratio of organic matter. Mineralization of straw increased at high temperature. The amount of available N increment resulted in fast mineralization of straw, especially in rice and barley straw. Chinese milk vetch had the greatest mineralization rate at all temperatures and fertilization levels followed by narrow-leaf vetch. However, rice and barley straws with high C/N ratio immobilized the soil N at the initial incubation duration. Chinese milk vetch or narrow leaf vetch was not effectively mineralized in mixed treatments with rice or barley straw. The mineralization rate of organic matter was mostly affected by the C/N ratio of straw and temperature of incubation. Organic matter with low C/N ratio should be recommended to avoid the immobilization of soil N and the increasing mineralization rate of straw.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.6
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• pp.1269-1276
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• 2015

The methodology of utilizing Intensity-Duration-flood Quantity (IDQ) curve for flood alert and warning was introduced and its performance was evaluated. For this purpose the lumped parameter model was calibrated and validated for gauged basin data set and the index precipitation equivalent to alert and warning flood was estimated. The index precipitation and IDQ curves associated by three different Antecedant Moisture Conditions (AMCs) are made provision for various possible flood scenarios. The test basin is Wonju-cheon basin ($94.4km^2$) located in Gangwon province, Korea. The IDQ curves corresponding to alert (50% of design flood level) and warning (70% of design flood level) level was estimated using the Clark unit hydrograph based lumped parameter model. The performance evaluation showed 0.704 of POD (Probability of Detection), 0.136 of FAR (False Alarm Ratio), and 0.633 of CSI (Critical Success Index), which is improved from the result of IDQ with single fixed AMC.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3D
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• pp.205-212
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• 2012

The national highway traffic counts system consists of short duration counts and continuous counts. Unlike continuous counts, short duration counts are performed by collection of a few days period and thus, the magnitude of deviation of collected data from AADT varies depending upon when data collection takes place. Therefore, this study was done to find out the best months and days of data collection of each highway classification in order to enhance the accuracy of AADT estimation. Continuous counts, another type of the national traffic counts system, are performed by collection of 365-day period using a permanent traffic counter. Therefore, it is necessary to keep the number of days for which the counter malfunctions to a minimum in order to enhance the accuracy of data. However, from time to time the permanent traffic counter malfunctions due to various causes and thus, cannot collect data. Therefore, this study was done to find out whether the age of counter, the ratio of heavy vehicle volume to total traffic volume, etc. could be the direct causes of counter's malfunction based on the number of maintenance for a certain time period.

• Journal of the Korean Ceramic Society
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• v.31 no.9
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• pp.1076-1086
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• 1994

This study covers synthetic effect of the various hydrothermal treatments on formation of artificially made kaolinite mineral. The hydrothermal treatment includes the temperature treatment with time duration, addition of seeds, particle size of the starting material used, pH variation and the different types of organic acids. A colloidal silica and alumina sol which are commercially available are used for this study. A colloidal silica and alumina sol are mixed by the atomic ratio of Al/Si = 1, based on the theoretical kaolinite composition and calcined at $600^{\circ}C$ for 8 hours duration. It was found that the kaolinitic clay mineral was well developed; thereby, the different patterns of crystalline mineral are appeared. Spherical type as a crystal form was distinctively formed at the temperature of 20$0^{\circ}C$ to 25$0^{\circ}C$ with short duration time, while platy type as a crystal was highly yielded at 300~35$0^{\circ}C$. Moreover, by adding more than 20 wt% of seed as the natural kaolinitic clay to the starting material is widely distributed and developed when 2 ${\mu}{\textrm}{m}$ or less particle size of the starting material is used; also, when they are heat-treated at the temperature of 25$0^{\circ}C$ with 5 hours duration. With respect of the effect of pH variation on formation of the synthetic kaolinite minerals, the crystalline minerals are highly yielded at less than pH 2 and gradually diminished at more than pH9. Regarding to the effect of different acids on development of the kaolinite mineral, the organic acids with high chelating capacity produces good formation of crystalline minerals; whereas, amine radical-(NH2) is not an effective agent to generate the crystalline minerals.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.286-298
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• 2018

This study presents determinants of resettlement considering population, economy, residential environment, policy characteristic, proposes implications for increase of resettlement. The research method deducted determinants of resettlement by union groups using logistic regression, union members are divided to more 10 years group and under 10 years group focused on real estate ownership duration. The analysis results are summarized as follows. More 10 years group has higher age, neighborship, satisfaction about pre-sale price, inside region in redevelopment promotion project, satisfaction about increase of real estate price, the higher resettlement decision probability. Under 10 years group has higher satisfaction about increase of real estate price, satisfaction about pre-sale price, satisfaction about floor area ratio incentive, the higher resettlement decision probability. the political implications must be customized financial support considering economic situations and increase of asset value by real estate ownership duration.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.65-70
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• 2016

Lung cancer is one of the most common malignancies in the world. Its incidence and mortality rates are on the rise in Pakistan. However, epidemiological studies to identify common lung cancer determinants in the Pakistani population have been limited. In this study, data of 440 cases and 323 controls were collected from different hospitals in Peshawar and Islamabad, along with information about socio-demographic factors including age, sex and smoking. Univariate and multi-factorial analyses of socio-demographic factors in association with each other were also performed. Overall survival analysis highlighted that, out of 440 patients in the lung cancer dataset, 204 people were uncensored with a median survival time of 13 months (95% CI=12-18). There were 41 femaleand 399 male patients. Differences were observed between length of survival in the males and females (${\chi}12$ = 6.1; p-value = 0.01). Gender was observed to be significantly related to survival (p-value< 0.01), with better survival in females (hazard ratio=2). Cox regression was extended to adjust for the covariate age (z = 2.5; p-value = 0.02). Survival analysis was also performed on the basis of smoking groups (current smokers, former smokers and never smoked individuals) and smoking duration (smoking duration >10 years, <10 years and never smoked). Smoking duration was significantly associated with survival (p-value < 0.01), with better survival in never smokers in comparison to both smoking for greater or less than 10 years. Strong associations were observed for smoking group with duration greater than 10 years, OR=6.1(3.9-9.5) on univariate and multifactorial analysis OR=11.3(CI=6.8-19.3).

• Journal of Korean society of Dental Hygiene
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• v.14 no.6
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• pp.921-926
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• 2014

Objectives: The purpose of the study is to investigate the factors associated with gingival bleeding(GB) by tooth brushing in college students. Methods: A self-reported questionnaire was filled out by 232 college students in Daegu Health College from March to June, 2014. Data were analyzed for frequency, chi square test, and logistic regression analysis using SPSS 12.0 program. The study was a cross sectional study. The questionnaire consisted of general characteristics of the subjects(gender, age, marital status, and smoking), frequency and duration of tooth brushing, scaling experience, and physical health status. Self-reporting hemorrhage was reported by yes or no. Frequency of tooth brushing was documented as the number of behavior. Above 4 times of tooth brushing was defined as 4. Duration of tooth brushing was documented as minute. Above 4 minutes, it was recorded as 4. In physical health status, 1 is feeling weak and 4 is feeling very healthy. Cronbach alpha was 0.82 in the study. Results: There were significant relationships between gingival bleeding and age(p<0.05), subjective health(p<0.01), tooth brushing frequency(p<0.05) and duration(p<0.05) by chi square test. Logistic regression analysis showed that the age(p<0.05), subjective health(p<0.01), tooth brushing frequency(p<0.05) and duration(p<0.05) were associated with gingival bleeding. Prevalence of gingival bleeding in 20 years was 0.62(odds ratio 1.85, 95% CI 1.00~3.43) and it was higher than that in 10 years. Prevalence of gingival bleeding in good health group was -1.38 and it was lower than that in poor health group. Conclusions: The factors associated with gingival bleeding were age, subjective health, and tooth brushing frequency and time.

• Journal of Korean Neurosurgical Society
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• v.46 no.3
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• pp.210-214
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• 2009

Objective : Several surgical procedures have been reported for the treatment of chronic subdural hematoma (CSDH). We compared the results of treatments for CSDH obtained from one burr-hole craniostomy with closed system drainage with or without irrigation, two burr-hole craniostomy with closed system drainage with irrigation, and small craniotomy with irrigation and closed-system drainage. Methods : Eighty-seven patients with CSDH underwent surgery at our institution from January 2004 to December 2008. Our patients were classified into three groups according to the operative procedure; group I, one burr-hole craniostomy with closed system drainage with or without irrigation (n=25), group II, two burr-hole craniostomy with closed system drainage with irrigation (n=32), and group III, small craniotomy with irrigation and closed-system drainage (n=30). Results : Age distribution, male and female ratio, Markwalder's grade on admission and at the time of discharge, size of hematoma before and after surgery, duration of operation, Hounsfield unit of hematoma before and after surgery, duration of hospital treatment, complication rate, and revision rate were categories that we compared between groups. Duration of operation and hospitalization were only two categories which were different. But, when comparing burr hole craniostomy group (group I and group II) with small craniotomy group (group III), duration of post-operative hospital treatment, complication and recurrence rate were statistically lower in small craniotomy group, even though operation time was longer. Conclusion : Such results indicate that small craniotomy with irrigation and closed-system drainage can be considered as one of the treatment options in patients with CSDH.

• Journal of Oral Medicine and Pain
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• v.46 no.2
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• pp.33-40
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• 2021

Purpose: Oral candidiasis is the most common fungal infection in the oral cavity which is usually diagnosed from clinical findings. A retrospective study was conducted to identify risk factors for oral candidiasis and to characterize the demographic and clinical features of affected patients. Methods: From January 1, 2019 to December 31, 2019, it consisted of 90 oral candidiasis patients diagnosed based on clinical finding and treated with antifungal drugs. As a retrospective study of those people, surveys were conducted on sex, age, systemic disease, a use of dentures, complaints of dry mouth, smoking and alcohol consumption, culture on potato dextrose agar (PDA) medium, culture on chromogenic agar (CA) medium and a duration of antifungal treatment. Results: Among 90 selected patients, the male and female ratio was 41:49. Overall, female had a higher infection rate than male in all age groups. In this study, oral candidiasis was not clearly susceptible to dry mouth, smoking or drinking, wearing dentures and association with systemic disease. Among 90 patients with oral candidiasis, 83 had colonies formed on PDA medium and 53 had colonies formed on CA medium. The duration of antifungal treatment was highest between 5 and 8 weeks. In addition, there was statistical significance between the culture results in CA medium and the duration of antifungal treatment. Conclusions: Generally, old age or infants, dry mouth, smoking, a use of dentures and endocrine abnormalities are risk factors to increase oral candidiasis; however, in this study, it was mainly found in the elderly aged 60 or older regardless of sex and the incidence of oral candidiasis was not obviously related with patients with dry mouth, smoking or drinking, denture wearers and endocrine abnormalities. Interestingly, when the fungi were cultured in CA medium, the duration of antifungal treatment was increased.

• The Korean Journal of Pain
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• v.34 no.1
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• pp.72-81
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• 2021

Background: In the literature, there have been debates as to whether smartphone use has negative effects on physical and mental health. The present study investigated the extent to which smartphone addiction impacts on musculoskeletal pain prevalence among university students. Methods: The questionnaire consisted of three sections: demographic information, the Smartphone Addiction Scale (SAS), and the modified Nordic Musculoskeletal Questionnaire. Results: A total of 249 participants were included in this cross-sectional study. The body parts that were reported with highest prevalence of musculoskeletal pain were the upper back (70.3%), neck (65.9%), and wrists/hands (68.7%). The SAS scores were correlated with duration of smartphone use on a typical day (P = 0.001), duration of owning a smartphone (P = 0.027), and musculoskeletal pain prevalence in the neck (P = 0.001), wrists/hands (P = 0.001), shoulders (P = 0.025), and upper back (P = 0.023). The SAS score was significantly associated with prevalence of musculoskeletal pain in the neck (odd ratio [OR], 1.08; 95% confidence interval [CI], 0.98-1.10; P = 0.002), wrists/hands (OR, 1.07; 95% CI, 0.97-1.09; P = 0.001), and upper back (OR, 1.10; 95% CI, 0.98-1.11; P = 0.033). Conclusions: The findings indicated that the upper back, neck, and wrists/hands have a higher prevalence of musculoskeletal pain among smartphone users, particularly those with a smartphone addiction. Smartphone addiction scores were correlated with duration of smartphone use on a typical day, duration of owning smartphone, and musculoskeletal pain prevalence in the neck, wrists/hands, shoulders, and upper back.