• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.3
• /
• pp.451-458
• /
• 2012

This study was conducted to investigate the characteristic factors which have been influenced on nitrous oxide ($N_2O$) emissions related to the environment change of nitrogen application level, rainfall and temperature during the soybean cultivation at black volcanic ash soil from 2010 to 2011. During the soybean cultivation, the more amount of nitrogen fertilizer applied, $N_2O$ emissions amounts were released much. $N_2O$ emissions with the cultivation time were released much at the first and middle of cultivation with heavy rainfall, but it was released very low until the end of cultivation and drought season. $N_2O$ emissions mainly were influenced by the rainfall and soil water content. The correlation ($r$) with $N_2O$ emissions, soil water, soil temperature and soil EC in 2010 were very significant at $0.4591^{**}$, $0.6312^{**}$ and $0.3691^{**}$ respectively. In 2011, soil water was very significant at $0.4821^{**}$, but soil temperature and soil EC were not significant at 0.1646 and 0.1543 respectively. Also, $NO_3$-N and soil nitrogen ($NO_3-N+NO_4-N$) were very significant at $0.6902^{**}$ and $0.6277^*$ respectively, but $NO_4$-N was not significant at 0.1775. During the soybean cultivation, the average emissions factor of 2 years released by the nitrogen fertilizer application was presumed to be 0.0202 ($N_2O$-N kg $N^{-1}\;kg^{-1}$). This factor was higher about 2.8 and 2 times than the Japan's (0.0073 $N_2O$-N kg $N^{-1}\;kg^{-1}$) value and 2006 IPCC guideline default value (0.0100 $N_2O$-N kg $N^{-1}\;kg^{-1}$) respectively.

• Korean Journal of Psychosomatic Medicine
• /
• v.20 no.1
• /
• pp.59-65
• /
• 2012

Objectives : The present study takes part of the agricultural district cohort study of a certain county located in Gyeonggido and aims to investigate the difference of the heart rate variability(HRV) according to the social support level. Methods : We used data from 1727 participants of a health promotion program who are older than 40 years old. A physical examination, as well as a one-to-one interview to obtain sociodemographic characteristics, was performed with each participant. In addition, the participants completed the Medical Outcomes Study-Social Support Survey(MOS-SSS) for their the social support level to be assessed, and their HRV were measured to evaluate their autonomic function. The entire group was divided in two groups according to its MOS-SSS points to facilitate the research. Those who were evaluated as the high 25%(432 persons) were denominated as high social support (HSS) group and those who were evaluated as the low 25%(425 persons) were denominated as poor social support(PSS) group. Results : The two groups showed significant differences on the sociodemographic factor such as mean age and gender composition(p<0.05). Comparing the indices related to the HRV, the HSS group had the following values higher than the PSS group : SDNN(F=4.938, p=0.027), TP(F=8.088, p=0.005), VLF(F=6.220, p=0.013) LF (F=3.873, p=0.049). Conclusion : According to the research, the PSS group showed dysfunction on their autonomic nervous system comparing to the HSS group. The social support helps an individual overcome difficulties, helps the adaptation during the changes of circumstances and in stressful situations it serves like a buffer. Based on that, it's possible to define that a low social support level gave an impact on the autonomic function. Also, using the fact that the HRV can evaluate the autonomic function in an objective view, it was possible to visualize that it has a potential to be used as an assistant factor to evaluate the social support.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.10
• /
• pp.656-663
• /
• 2012

After the construction of waterworks automatic meter reading with 15 mm diameter digital water mater with magnetoresistance sensor developed in this study at 96 households of apartment complexes located in Incheon-City B-Gu S-Dong, the feasibility of field application of waterworks automatic meter reading was evaluated. The field application of waterworks automatic meter reading was performed from July to December in 2011, and average reception rate was as low as 84.6% due to the instable wibro networks, the existence of communication blackout and temporary malfunction of router. After the extraction of 10 households with one to five residents out of 96 households by using stratified random sampling method and analysis of domestic water use, it was found that domestic water use was significant at August and showed a decreasing trend at September, followed by increase in domestic water use at November and decrease in domestic water use at December. This phenomenon should be attributed to weather factors (temperature, humidity, etc.), which significantly affected domestic water use. Similar trend in domestic water use in terms of weather factors was obtained in case of Liter per capita day of water use after the extraction of 30 households out of 96 households by using stratified random sampling method. After analysis of Liter per capita day for 96 households, single residents increases resulted in reduction of domestic water usage by about 14% of Liter per capita day. These results might be due to the fact that domestic water usage such as laundry, beverages, catering, cleaning, etc. should be required for even the household with one resident, whereas domestic water usage for those common utilization can be significantly saved for the household with more than one resident.

• Weed & Turfgrass Science
• /
• v.2 no.1
• /
• pp.8-14
• /
• 2013

Collection of weeds were done in 3 remodeled paddy fields located in different districts with different soil moisture conditions such as Samolpo district (14.6%), Gimhae (9.8%) and Chilhyun (5.6%). Remodeled paddy fields composed of 62 plant species belonging to 23 families. Among 23 families, Compositae was the largest family with 11 species belonged to (17.7%) followed by Poaceae with 9 species (14.5%), Leguminosae with 8 species (12.9%), Cyperaceae with 7 species (11.3%), and Polygonaceae with 5 species (8.1%). Summed dominance ratio of each species based on number, coverage, frequency, and plant height in Samolpo district was Echinochloa oryzoides (100%) > Cyperus difformis (9.0%) > Bidens frondosa (5.3%) > Panicum dichotomiflorum (4.8%) > Eclipta prostrata (4.4%). In Gimhae; Digitaria ciliaris (100%) > Panicum dichotomiflorum (49.4%) > Echinochloa oryzoides (48.8%) > Persicaria hydropiper (27.1%) > Chenopodium ficifolium (10.2%), and in Chilhyun were Panicum dichotomiflorum (90.8%) > Digitaria ciliaris (66.7%) > Cyperus iria (8.6%) > Bidens frondosa (7.6%). Total dry weight of weeds recorded was 535.4 g $m^{-2}$, 316.1 g $m^{-2}$ and 346.2 g $m^{-2}$ in Samolpo, Gimhae and Chilhyun districts, respectively. Simpson's index was calculated to 0.09~0.28, which showed that weed occurrence in remodeled paddy fields with different soil moistures varied.

• Tuberculosis and Respiratory Diseases
• /
• v.44 no.1
• /
• pp.146-153
• /
• 1997

Background : Chronic cough is commomly defined as a persistent or recurrent cough exceeding 3 week's duration. The prevalence of chroinc cough is reported to range from 14% to 23 % for nonsmoking adults. The post nasal drip syndrome has been determined to be the most common cause of chronic cough, followed by asthma, chronic bronchitis, gastroesophageal reflux and bronchiectasis. Cough can be the only manifestation of asthma. Bronchial provocation tests are useful in diagnosing cough variant asthma. We investigated the clinical or laboratory findings and the incidence of airway hyperresponsiveness and evaluated the etiology in patients with chronic cough. Method : We evaluated 46 patients with chronic cough. Methacholine challenge test were done. Results : The results were as follows : 1) Thirty - five percent(16/46) of the chronic cough patients and 44% of the post nasal drip syndrom(7/16) showed the positive responses to methacholine challenge test 2) The underlying causes of chronic cough were post nasal drip syndrome in 35%, bronchitis in 21.7%, cough-variant asthma in 17.4%, and unknown condition in 25.9%. 3) Airway hyperresponsiveness in chronic cough was not related to respiratory symptom, nasal symptom, post nasal drip, smoking, derangement of ventilatory function, atopy, or sinusitis. Conclusion : Airway hyperresponsivenss in patients with chronic cough increased in frequency when compaired with normal control, allergic rhinitis. Cough-variant asthma account for 17.4% of patients with chronic cough.

• Journal of Intelligence and Information Systems
• /
• v.22 no.1
• /
• pp.159-185
• /
• 2016

Planning a multi-day trip is a complex, yet time-consuming task. It usually starts with selecting a list of points of interest (POIs) worth visiting and then arranging them into an itinerary, taking into consideration various constraints and preferences. When choosing POIs to visit, one might ask friends to suggest them, search for information on the Web, or seek advice from travel agents; however, those options have their limitations. First, the knowledge of friends is limited to the places they have visited. Second, the tourism information on the internet may be vast, but at the same time, might cause one to invest a lot of time reading and filtering the information. Lastly, travel agents might be biased towards providers of certain travel products when suggesting itineraries. In recent years, many researchers have tried to deal with the huge amount of tourism information available on the internet. They explored the wisdom of the crowd through overwhelming images shared by people on social media sites. Furthermore, trip planning problems are usually formulated as 'Tourist Trip Design Problems', and are solved using various search algorithms with heuristics. Various recommendation systems with various techniques have been set up to cope with the overwhelming tourism information available on the internet. Prediction models of recommendation systems are typically built using a large dataset. However, sometimes such a dataset is not always available. For other models, especially those that require input from people, human computation has emerged as a powerful and inexpensive approach. This study proposes CYTRIP (Crowdsource Your TRIP), a multi-day trip itinerary planning system that draws on the collective intelligence of contributors in recommending POIs. In order to enable the crowd to collaboratively recommend POIs to users, CYTRIP provides a shared workspace. In the shared workspace, the crowd can recommend as many POIs to as many requesters as they can, and they can also vote on the POIs recommended by other people when they find them interesting. In CYTRIP, anyone can make a contribution by recommending POIs to requesters based on requesters' specified preferences. CYTRIP takes input on the recommended POIs to build a multi-day trip itinerary taking into account the user's preferences, the various time constraints, and the locations. The input then becomes a multi-day trip planning problem that is formulated in Planning Domain Definition Language 3 (PDDL3). A sequence of actions formulated in a domain file is used to achieve the goals in the planning problem, which are the recommended POIs to be visited. The multi-day trip planning problem is a highly constrained problem. Sometimes, it is not feasible to visit all the recommended POIs with the limited resources available, such as the time the user can spend. In order to cope with an unachievable goal that can result in no solution for the other goals, CYTRIP selects a set of feasible POIs prior to the planning process. The planning problem is created for the selected POIs and fed into the planner. The solution returned by the planner is then parsed into a multi-day trip itinerary and displayed to the user on a map. The proposed system is implemented as a web-based application built using PHP on a CodeIgniter Web Framework. In order to evaluate the proposed system, an online experiment was conducted. From the online experiment, results show that with the help of the contributors, CYTRIP can plan and generate a multi-day trip itinerary that is tailored to the users' preferences and bound by their constraints, such as location or time constraints. The contributors also find that CYTRIP is a useful tool for collecting POIs from the crowd and planning a multi-day trip.

• Korean Journal of Environmental Biology
• /
• v.33 no.4
• /
• pp.441-449
• /
• 2015

This study was conducted to screen the characteristics of external and cranial characters of Crocidura shantungensis collected from Korean Peninsula, Ulleung Island and Jeju Island. There were significant differences in head-body length (HBL), tail length (TL), ear length (EL), and hind foot length (HFL) in males and HBL, TL, and HFL in females among three populations (p<0.05). The HBL and TL in the Jeju Island population were larger (8.0 mm and 4.0 mm in lengths, respectively) than those of the Korean Peninsula population. Based on skull analysis, a total of thirteen traits showed significant differences among the three populations (p<0.05). The condylo-insicive length (CIL), maximum width of brain case (MWB), mandibular length (ML), and mandibular height (MH) in the Jeju Island population were significantly larger than those of Korean Peninsula population (p<0.05). Principle component analysis (PCA) showed that two principle components (PC) identified from the PCA affected on the body size and width of the skull, respectively. Discriminant analysis revealed that these populations could be discriminated through skull traits. These findings concluded that the Jeju Island population was greater in the size than the Korean Peninsula, suggesting that the Jeju Island shrews have successfully adapted to the island environments and they had morphologically differentiated during glacial period after natural immigration into that Island. Thus, this study supports the 'Island Rule', showing that the population is well adapted to the island environments. This may provide important information for biogeographical and ecological studies on insular animals.

• Journal of Wetlands Research
• /
• v.3 no.1
• /
• pp.1-17
• /
• 2001

The flora, vegetation structure, distribution of the vascular plants, physico-chemical characteristics of sediment, and nutrient contents of palnts were investigated in the ten disturbed and undisturbed wetlands around the littoral zone of Namgang, Jinju-si, Gyongsangnam-do, Korea from August 7 to August 15 in 1999. 217 taxa of the vascular plants distributed into 2 formas, 26 varieties, 189 species belong to 142 genera under 52 families were sampled or recorded. Dominant species of the undisturbed and the disturbed area were Persicaria thunbergii and Ambrosia artemisiifolia var. elatior, of which importance values were 13.86, and 15.81, respectively. Among 26 species of the naturalized plants, importance value of Ambrosia artemisiifolia var. elatior was highest as 9.54. The ranges of species diversity indices (H') were 1.370~1.819, and highest in the site 1 of the undisturbed area. The ranges of eqitability (J') were 0.779~0.902, and highest in the site 8 of the disturbed area. The ranges of community similarity indices ($CC_s$) were 0.341~0.578 among the ten wetlands, and highest between site 1 and site 2 which were the undisturbed area. The ranges of sediment properties such as pH, conductivity, organic matter, total phosphorus, and total nitrogen were 5.17~7.35, $24.67{\sim}74.33{\mu}mhocm^{-1}$, 1.09~3.82%, 0.0008~0.0034 mg/100g, and 0.06~0.15%, respectively. Nutrient contents of plants such as total nitrogen and total phosphorus were 1.52~2.65% and $0.010{\sim}0.039mg100g^{-1}$, respectively. It was recommended that the establishment of the conservation area was necessary to ensure the habitat for wild life and to maintain the diversity of the vascular hydrophytes and hygrophytes.

• Journal of dental hygiene science
• /
• v.11 no.2
• /
• pp.69-76
• /
• 2011

The aim of this study was to compare the effects on the resistance to demineralization by the frequency and method of fluoride application in vitro. ninety-one human enamel specimens were embedded in acrylic resin with the labial surfaces exposes. The specimens were divided into 7 groups; (1) non-treated; (2) 1.23% APF gel 1 time; (3) 2% NaF sol 1 time; (4) 2% NaF sol iontophoresis 1 time; (5) 1.23% APF gel 4 time; (6) 2% NaF sol 4 time; (7) 2% NaF sol iontophoresis 4 time. All the groups were immersed in the remineralizing solution (RS) before baseline and divided into 7 test groups of 13 specimens each. All the specimens were exposed to a pH-cycling model which consisted of demineralization (6 hours) and remineralization (18 hours) for 5 days. The Vickers surface micro-hardness number of all the specimens was measured using microhardness tester and the specimen surfaces were observed by scanning electron microscope (SEM). The results were analyzed using one-way ANOVA followed a Tukey's multiple comparison at a significance level of 0.05. The group 7 showed higher level of microhardness after Fluoride application. The group 1 showed lowest level of microhardness but group 7 showed higher level of microhardness after pH-cycling model, there were significant differences between groups. After the modified pH-cycling, the 2% NaF solution with the iontophoresis group showed the best resistance to demineralization(p<0.05). These results were also confirmed by SEM. The fluoride iontophoresis method was the most effective of the regimens in increasing the acid resistance of the enamel.

• Journal of Life Science
• /
• v.23 no.9
• /
• pp.1109-1117
• /
• 2013

Induction of G1 Arrest by Methanol Extract of Lycopus lucidus in Human Lung Adenocarcinoma A549 Cells Lycopus lucidus, a herbaceous perennial, is used as a traditional remedy in East Asia, including China and Korea. It has been reported that L. lucidus has anti-allergic effects, inhibitory effects on cholesterol acyltransferase in high glucose-induced vascular inflammation, and anti-proliferative effects in human breast cancer cells. However, the molecular mechanisms of the anti-cancer effects of L. lucidus have not yet been fully determined. In this study, we evaluated the anti-cancer effect and the mechanism of action of L. lucidus in human lung adenocarcinoma A549 cells using methanol extracts of L. lucidus (MELL). MELL treatment showed cytotoxic activity in a dose-dependent manner and induced G1 arrest in A549 cells. The induction of G1 arrest by MELL was associated with the up-regulation of phospho-CHK2 and the down-regulation of Cdc25A phosphatase. In addition, MELL treatment induced decreased expression of G1/S transition-related proteins, including CDK2, CDK4, CDK6, cyclin D1 and cyclin E. MELL also regulated the mRNA expression of CDK2 and cyclin E. On the other hand, the expression of p53 and the cyclin-dependent kinase inhibitor p21 was not induced by MELL. Collectively, these results suggest that MELL may exert an anti-cancer effect by cell cycle arrest at G1 phase through the ATM/CHK2/Cdc25A/CDK2 pathway in A549 cells.