• Title/Summary/Keyword: frequency of occurrence

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A Study for Monitoring Soil Liquefaction Occurred by Earthquakes Using Soil Moisture Indices Derived from the Multi-temporal Landsat Satellite Imagery Acquired in Pohang, South Korea (다중시기 Landsat 위성영상으로부터 산출한 토양 수분 지수를 활용하여 지진 발생으로 인한 토양 액상화 모니터링에 관한 연구: 포항시를 사례로)

  • PARK, Insun;KIM, Kyoung-Seop;HAN, Byeong Cheol;CHOUNG, Yun-Jae;GU, Bon Yup;HAN, Jin Tae;KIM, Jongkwan
    • Journal of the Korean Association of Geographic Information Studies
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    • v.24 no.1
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    • pp.126-137
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    • 2021
  • Recently, the number of damages on social infrastructure has increased due to natural disasters and the frequency of earthquake events that are higher than magnitude 3 has increased in South Korea. Liquefaction was found near the epicenter of a 5.4 magnitude earthquake that occurred in Pohang, South Korea, in 2017. To explore increases in soil moisture index due to soil liquefaction, changes in the remote exploration index by the land cover before and post-earthquake occurrence were analyzed using liquefaction feasibility index and multi-cyclical Landsat-8 satellite images. We found that the soil moisture index(SMI) in the liquefaction region immediately after the earthquake event increased significantly using the Normal Vegetation Index(NDVI) and Surface Temperature(LST).

A Study on the Method of Scholarly Paper Recommendation Using Multidimensional Metadata Space (다차원 메타데이터 공간을 활용한 학술 문헌 추천기법 연구)

  • Miah Kam;Jee Yeon Lee
    • Journal of the Korean Society for information Management
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    • v.40 no.1
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    • pp.121-148
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    • 2023
  • The purpose of this study is to propose a scholarly paper recommendation system based on metadata attribute similarity with excellent performance. This study suggests a scholarly paper recommendation method that combines techniques from two sub-fields of Library and Information Science, namely metadata use in Information Organization and co-citation analysis, author bibliographic coupling, co-occurrence frequency, and cosine similarity in Bibliometrics. To conduct experiments, a total of 9,643 paper metadata related to "inequality" and "divide" were collected and refined to derive relative coordinate values between author, keyword, and title attributes using cosine similarity. The study then conducted experiments to select weight conditions and dimension numbers that resulted in a good performance. The results were presented and evaluated by users, and based on this, the study conducted discussions centered on the research questions through reference node and recommendation combination characteristic analysis, conjoint analysis, and results from comparative analysis. Overall, the study showed that the performance was excellent when author-related attributes were used alone or in combination with title-related attributes. If the technique proposed in this study is utilized and a wide range of samples are secured, it could help improve the performance of recommendation techniques not only in the field of literature recommendation in information services but also in various other fields in society.

An Optimal Sewer Layout Model to Reduce Urban Inundation (도시침수 저감을 위한 최적 우수관망 설계 모형)

  • Lee, Jung-Ho;Kim, Joong-Hoon;Jun, Hwan-Don
    • Journal of Korea Water Resources Association
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    • v.44 no.10
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    • pp.777-786
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    • 2011
  • In the previous researches for storm sewer design, the flow path, pipe diameter and pipe slope were determined to minimize the construction cost. But in the sewer networks, the flows can be changed according to flow path. The current optimal sewer layout models have been focussed on satisfying the design inflow for sewer designs, whereas the models did not consider the occurrences of urban inundation from excessive rainfall events. However, in this research, the sewer networks are determined considering the superposition effect to reduce the inundation risk by controlling and distributing the inflows in sewer pipes. Then, urban inundation can be reduced for excessive rainfall events. An Optimal Sewer Layout Model (OSLM) was developed to control and distribute the inflows in sewer networks and reduce urban inundation. The OSLM uses GA (Genetic Algorithm) to solve the optimal problem for sewer network design and SWMM (Storm Water Management Model) to hydraulic analysis. This model was applied to Hagye basin with 44 ha. As the applied results, in the optimal sewer network, the peak outflow at outlet was reduced to 7.1% for the design rainfall event with 30 minutes rainfall duration versus that of current sewer network, and the inundation occurrence was reduced to 24.2% for the rainfall event with 20 years frequency and 1 hour duration.

Assessment of statistical errors of articles published in the Journal of the Korean Academy of Prosthodontics: 2006 - 2010 (대한치과보철학회지에서 볼 수 있는 통계적 오류의 고찰(2006 - 2010))

  • Kang, Dong-Wan;Seo, Yunam;Oh, Nam-Sik;Lim, Hoi-Jeong
    • The Journal of Korean Academy of Prosthodontics
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    • v.50 no.4
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    • pp.258-270
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    • 2012
  • Purpose: Use of inappropriate statistical methods may lead to incorrect conclusions and a waste of valuable resources. The goal of this study was to assess the frequency and the types of several common statistical errors in the published articles of the Journal of the Korean Academy of Prosthodontics (JKAP) for a 5-year period. Materials and methods: Of 336 articles in the JKAP published from 2006 to 2010, 255 articles using statistics were reviewed and classified by statistical method and year. The frequency and types of the statistical methods were examined, and the statistical errors were evaluated by the appropriateness of the experimental design, assumption check, independent outcomes, proper sample size and suitable use of statistical method. Statistical guidelines were completed based on the appropriateness. Results: Of the 255 articles using statistics, 193 articles (75.9%) used inferential statistics and 153 articles used SPSS statistical software (60.0%). Of the articles using inferential statistics, the three most frequently used statistical methods were ANOVA (41.5%), t-test (20.0%), and the nonparametric method (16.9%). The average rate of statistical errors was 61.2 percent, similar to the rate reported by several studies completed for the medical journal. Conclusion: After the whole analysis of the difference among the groups, post-hoc tests for the pairwise comparisons are required. The optimal sample size calculation is an essential part of this study protocol. To minimize the occurrence of statistical errors, statistical guidelines were developed according to each statistical test procedure and will contribute to the academic improvement in the JKAP.

A Study on the Characteristics and Consultation Request Type of Inpatients Referred for Depressive Symptoms (우울 증상으로 의뢰된 입원환자의 임상적 특징 및 자문 의뢰 형태에 관한 연구)

  • Yoon, Nara;Ryu, Seung-Ho;Ha, Jee Hyun;Jeon, Hong Jun;Park, Doo-Heum
    • Korean Journal of Psychosomatic Medicine
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    • v.29 no.1
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    • pp.34-41
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    • 2021
  • Objectives : The purpose of this study is to investigate the characteristics of depressive patients who admitted to general hospital. We examined the clinical characteristics of patients who were referred to the Department of Psychiatry as depressive symptoms, according to the type of consultation request, and comparing 'with re-consultation' and 'without re-consultation' groups. Methods : We performed a retrospective chart review of 4,966 inpatients who were referred to the Department of Psychiatry from August 2005 to December 2011. Results : For about 6 years, among the inpatients referred for psychiatric consultation, a total of 647 patients were referred for depressive symptoms, accounting for 13.82% of the total consultations. The average age of depressive patients was 58.6 years, which was higher than the average of 56.4 years of overall patients. Among the depressive patients, 275 patients were included in 'with re-consultation' group and there was no statistically significant difference when comparing 'with re-consultation' group and 'without re-consultation' group. However, there was a difference in the tendency of the two groups in the type of consultation request. 'With re-consultation' group was in the order of frequency of consultation type 3-2-1, whereas the 'without re-consultation' group was in the order of frequency of consultation type 2-3-1. Conclusions : The group of inpatients who were referred for depressive symptoms in general hospital showed the largest proportion of the group of patients referred to the Department of Psychiatry. 'With re-consultation' group had a higher rate of re-consultation due to the occurrence of new symptoms after hospitalization compared to 'without re-consultation' group. Therefore, doctors in each department and psychiatrists should pay attention to the depressive symptoms of inpatients and actively discuss treatment plans to improve the quality of medical services, identify risk factors, and make efforts to intervene early if necessary.

Epidemiological Pattern of Mycoplasma pneumoniae Pneumonia from 1993 Through 2002 and Clinical Characteristics during Recent Five Years (10년간(1993~2002) Mycoplasma 폐렴의 역학적 양상과 최근 5년간 Mycoplasma 폐렴의 임상소견에 대한 고찰)

  • Oh, Kyung-Chang;Yoo, Jung-Suk;Ahn, Seung-In;Kim, Bong-Rim;Kim, Sung-Seob;Kim, Yeon-Ho;Chang, Jin-Keun;Cha, Sung-Ho
    • Pediatric Infection and Vaccine
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    • v.11 no.1
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    • pp.101-111
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    • 2004
  • Purpose : This study was performed to observe the epidemiological pattern of M. pneumoniae pneumonia during the period from 1993 to 2002 and also to see some clinical characteristics of M. pneumoniae pneumonia during recent five years. Methods : We had performed a retrospective analysis of epidemiological pattern of occurrence in 682 patients with M. pneumoniae pneumonia admitted to Department of Pediatrics of Han-il General Hospital from January, 1993 to December, 2002. Results : The annual ratio of M. pneumoniae pneumonia was compared with the total numbers of respiratory tract infection patients. The ratios were 19.1% in 1993, 13.0% in 1994, 5.6% in 1995, 12.8% in 1996, 18.6% in 1997, 22.6% in 1998, 1.1% in 1999, 13.3% in 2000, 9.1% in 2001, 6.0% in 2002, and 19.9% in 2003. The epidemics have occurred in 1993, 1997, 1998, 2000, and 2003 years showing 3~4 year intervals. The peak incidence of age was four to six years old(286 cases; 41.9%) and male-to-female ratio was 1 : 1.1. Monthly distribution showed a high frequency from August to December and the major outbreak occurred in November(119 cases; 17.4%), in October(106 cases; 15.5%), and in December(96 cases; 14.1%) in order of frequency. The most common symptoms were cough (660 cases; 96.8%), fever(569 cases; 83.4%), and sputum(522 cases; 76.5%) in that order. Leukocytosis was observed in 31.2% of patients based on a normal range according to the adjusted age. Increased ESR(${\geq}20mm/hr$) was noted in 42.5% of cases and CRP was positive in 37.8% of cases. On the chest X-ray examination, pulmonary infiltration was noted in 557 cases(81.7%), and the patterns of pneumonic infiltration were bronchopneumonia(78.0%), lobar(35.5%), lobular(19.2%), and interstitial pneumonia(28.7%). Complications were paranasal sinusitis(41 cases), acute otitis media(23 cases), pleural effusion(19 cases). cervical lymphadenitis(18 cases), and glomerulonephritis(1 case). Conclusion : The pattern of M. pneumoniae pneumonia from 1997 to 2003 noted 3~4 year interval with peak monthly distribution of October and November compared with 3 year interval and peak incidence of summer period before 1996.

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Study on Fire Hazard Analysis along with Heater Use in the Public Use Facility Traditional Market in Winter (겨울철 다중이용시설인 전통재래시장 난방기구 사용에 따른 화재 위험성 분석에 관한 연구)

  • Ko, Jaesun
    • Journal of the Society of Disaster Information
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    • v.10 no.4
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    • pp.583-597
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    • 2014
  • Fire caused by heater has various causes as many as the types of heater. also, lots of damage of human life and property loss are caused, since annually continuous fire accident by heater in traditional market is frequently occurring. There are not many cases of fire due to heater in most of residential facilities such as general house, apartments, etc., because they are supplied with heating boiler, however the restaurant, store and office of the market, sports center, factory, workplace, etc. still use heater, e.g. oilstove, electric heater, etc., so that they are exposed to fire hazard. Also, when investigating the number of fire due to heater, it was analyzed to occur in order of home boiler, charcoal stove, oilstove, gas heater/stove, electric stove/heater, the number of fire per human life damage was analyzed in order of gas heater/stove, oil heater/stove, electric heater/stove, briquette/coal heater. Also, gas and oil related heater were analyzed to have low frequency, however, with high fire intensity. Therefore, this research aimed at considering more scientific fire inspection and identification approach by reenacting and reviewing fire outbreak possibility caused by combustibles' contact and conductivity under the normal condition and abnormal condition in respect of ignition hazard, i.e. minimum ignition temperature, carbonization degree and heat flux along with it, due to oilstove and electric stove, which are still frequently used in public use facility, traditional market, and, of which actual fire occurrence is the most frequent. As the result of reenact test, ignition hazard appeared very small, as long as enough heat storage condition is not made in both test objects(oilstove/electric stove), however carbonization condition was analyzed to be proceeded per each part respectively. Eventually, transition to fire is the ignition due to heat storage, so that it was analyzed to ignite when minimum heat storage temperature condition of fire place is over $500^{\circ}C$. Particularly, in case of quartz pipe, the heating element of electric stove, it is rapidly heated over the temperature of $600^{\circ}C$ within the shortest time(10sec), so that the heat flux of this appears 6.26kW/m2, which was analyzed to result in damage of thermal PVC cable and second-degree burn in human body. Also, the researcher recognized that the temperature change along with Geometric View Factor and Fire Load, which display decrease of heat, are also important variables to be considered, along with distance change besides temperature condition. Therefore, the researcher considers that a manual of careful fire inspection and identification on this is necessary, also, expects that scientific and rational efforts of this research can contribute to establish manual composition and theoretical basis on henceforth fire inspection and identification.

A Case-Control Study of Food Habits and Diet Intakes of Women with Gestational Diabetes Mellitus (임신성 당뇨병 환자의 식습관 및 식이섭취에 관한 환자-대조군 연구)

  • Ji, Sun-Kyung;Jang, Hak-C.;Choi, Hay-Mie
    • Journal of Nutrition and Health
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    • v.41 no.1
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    • pp.41-53
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    • 2008
  • Gestational diabetes mellitus (GDM) is defined as glucose intolerance discovered or onset during pregnancy and attention is needed because of increased risk of perinatal morbidties and higher incidence of diabetes afterward. This study was performed to identify dietary factors associated with the development of gestational diabetes mellitus (GDM). Developed food frequency questionnaire containing 192 food items were used to assess nutritional status of 246 control subjects and 104 GDM subjects. Food habits of subjects were examined in the questionnaire. The more irregularity and less variety of meal were found in GDM group compared to control group and GDM group tended to eat rapidly and do not like vegetables and greasy foods. Total score of food habits in GDM was lower than control group, which suggests that GDM group have undesirable food habits. Mean daily energy and carbohydrate intakes of GDM group were higher than those of control group, and percent energy from protein was significantly higher in control. Nutrient density of protein, calcium, phosphorus and vitamin BI of GDM group was significantly lower than those of control group. Therefore dietary quality of GDM group was lower than that of control group. Odds ratio for GDM was high when energy and carbohydrate intakes were high. And when the intakes of rice, noodle, shiruduk, hamburger, boiled egg, steamed pork shank were high, the odds ratio for GDM was high. These results indicate that the amount and frequencies of several foods and dish items were related with the occurrence of GDM subjects. On the whole, GDM subjects consumed more cereals and less vegetables and less legumes. From these results, pregnant women with GDM tended to have unhealthy food habits, and carbohydrate intake was important dietary factors on the onset of GDM.

A Long-term Variability of the Extent of East Asian Desert (동아시아 사막 면적의 경년변화분석)

  • Han, Hyeon-Gyeong;Lee, Eunkyung;Son, Sanghun;Choi, Sungwon;Lee, Kyeong-Sang;Seo, Minji;Jin, Donghyun;Kim, Honghee;Kwon, Chaeyoung;Lee, Darae;Han, Kyung-Soo
    • Korean Journal of Remote Sensing
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    • v.34 no.6_1
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    • pp.869-877
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    • 2018
  • The area of desert in East Asia is increasing every year, and it cause a great cost of social damage. Because desert is widely distributed and it is difficult to approach people, remote sensing using satellites is commonly used. But the study of desert area comparison is insufficient which is calculated by satellite sensor. It is important to recognize the characteristics of the desert area data that are calculated for each sensor because the desert area calculated according to the selection of the sensor may be different and may affect the climate prediction and desertification prevention measures. In this study, the desert area of Northeast Asia in 2001-2013 was calculated and compared using Moderate Resolution Imaging Spectroradiometer (MODIS) and Vegetation. As a result of the comparison, the desert area of Vegetation increased by $3,020km^2/year$, while in the case of MODIS, it decreased by $20,911km^2/year$. We performed indirect validation because It is difficult to obtain actual data. We analyzed the correlation with the occurrence frequency of Asian dust affected by desert area change. As a result, MODIS showed a relatively low correlation with R = 0.2071 and Vegetation had a relatively high correlation with R = 0.4837. It is considered that Vegetation performed more accurate desert area calculation in Northeast Asian desert area.

The Planting and Use of Landscaping Plants in Kangweon-Do (강원도내 조경식물의 배치과 이용)

  • 이기의;이우철;박봉우;조철길
    • Journal of the Korean Institute of Landscape Architecture
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    • v.15 no.3
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    • pp.33-50
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    • 1988
  • This study was executed to find out how to improve on the planting and use of the plants in Kangweon- Do by surveying the planting areas -gardens, parks, streets, schools, etc. - in five cities of this province, and to select available native plants by surveying the main mountains in this province. The results are as follows ; 1. The species number within surrey areas was 319 species. and the species of which planting frequency was very high were Hibiscus syriacus, Juniperus chinensis, Buxus microphylla v. koreana, etc.. 2. The species number of school trees and flowers of 202 schools in Kangweon-Do were 33 species, 32 species respectively. and the species of school trees and flowers that showed the highest preference were Juniperus chinensis, Forsythia koreana each. 3. The species number of flowers and trees designated in 22 City and Keun were 14 species, 7 species respectively, and the species of flowers and trees that presented the highest designation frequency were Rhododendron schlippenbachii, Ginkgo biloba each. 4. The street trees planted along the main streets in Kangweon-Do were 18 species and 84,939 individuals, and the ratio of Populus alba${\times}$glandulosa was the highest among occurrence individuals. 5, As for the composition ratios of life forms of plants within survey areas, the ratio of deciduous broad-leaved tree was the highest as about 56% and that of deciduous coniferous tree was the lowest as about 1.6%. The ratios of native species versus exotic were 43 : 57 6. Through these results, it was thought that the diversification of planing species, the selection of plants suitable to each space and the generalization of use of native species were needed. So 254 plants native to Kangweon-Do were presented to correspond to these requirements.

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