• Title/Summary/Keyword: observational analysis

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DESIGN AND IMPLEMENTATION OF A PROTOCOL VERIFICATION SYSTEM (프로토콜 검증시스템의 설계 및 구현)

  • Kim, Yong-Jin
    • ETRI Journal
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    • v.11 no.4
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    • pp.22-36
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    • 1989
  • In this paper, a design and implementation of an efficient protocol verification system named LOVE has been described. The LOVE has been developed specifically for LOTOS. It performs not only protocol syntax validation (PSV) but also protocol functional verification(PFV). The PSV is a test to check if a protocol is free from protocol syntax errors such as deadlocks and livelocks. The PFV confirms whether or not a protocol achieves its functional objectives. For the PSV, the reachability analysis is employed, and the observational equivalence test is used for the PFV. For protocol verification using the LOVE, a schematic protocol verification methodology has been outlined.

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Preliminary Study on Settlement Prediction of Thick Soft Clay Deposits (대심도 연약지반에 적용가능한 침하예측기법 개발을 위한 기초적 연구)

  • 정하익;진현식
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.725-730
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    • 2002
  • The areas around the Nam-Hae are mostly covered in thick soft clay deposits(50∼60.0m). In order to improve the ground in these areas verticals trains have been partially penetrated up to the depth of about 25.0m. However, since the predicted values of settlement have often been changed at some predicted time. Finite element analysis was performed to investigate the consolidation behaviour for it. The results from FEM was compared with various observational methods.

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The Comparison Study on Observational Before-After Studies: Case Study on Safety Evaluation on Highways (관찰적 사전·사후 평가연구 방법의 비교 연구: 공용중인 고속도로 안전진단사업 효과평가를 사례로)

  • Mun, Sung Ra;Lee, Young-Ihn
    • Journal of Korean Society of Transportation
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    • v.31 no.6
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    • pp.67-89
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    • 2013
  • This study is to perform empirical analysis on observational before-after studies in Naive Method, Comparison Group(CG) Method and Empirical Bayes(EB) Method, and to compare with their results and to propose ways to apply to evaluation researches. For this purpose, the evaluation of road safety audit executed on Y$\breve{o}$ng-dong freeway in 2005 and 2006 was performed. As a result, all three methods have showed improved effects due to safety treatments. The safety effectiveness of Naive method is the largest, CG Method is the second and EB method is the last. The results of Naive method are overestimated due to the trend of reducing traffic accidents and those of CG method are affected by the external casual effects of comparison group. In the EB method, as "regression to the mean" phenomenon are controlled by reference group's accident model, it's result is relatively more accurate than that of other methods. In the conduct of evaluation studies, the analysts have to understand the pros and cons of each evaluation method. And after leading the survey on accident trends of related all sites, evaluation analysis is performed to be able to minimize bias.

Application of genetic Algorithm to the Back Analysis of the Underground Excavation System (지하굴착의 역해석에 대한 유전알고리즘의 적용)

  • 장찬수;김수삼
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.65-84
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    • 2002
  • The Observational Method proposed by Terzaghi can be applied for the safe and economic construction projects where the exact prediction of the behavior of the structures is difficult as in the underground excavation. The method consists of measuring lateral displacement, ground settlement and axial force of supports in the earlier stage of the construction and back analysis technique to find the best fit design parameters such as earth pressure coefficient, subgrade reaction etc, which will minimize the gap between calculated displacement and measured displacement. With the results, more reliable prediction of the later stage can be obtained. In this study, back analysis programs using the Direct Method, based on the Hill Climbing Method were made and evaluated, and to overcome the limits of the method, Genetic Algorithm(GA) was applied and tested for the actual construction cases.

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Effects of Nonsurgical Spinal Decompression Treatment on the Level of Pain and Quality of Life in Patients with Cervical or Lumbar Disc Herniation: A Retrospective Observational Study

  • Kim, Beom Seok;Lee, Ye Ji;Kim, Hyo Bin;Sung, Ki Jung;Jeon, Ju Hyun;Kim, Eun Seok;Kim, Young Il
    • Journal of Acupuncture Research
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    • v.37 no.4
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    • pp.259-269
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    • 2020
  • Background: This study aims to statistically analyze and compare the curative effect and satisfaction level between typical traditional Korean medicine treatment and nonsurgical spinal decompression treatment. Methods: Of the patients who were diagnosed with the cervical or lumbar herniated intervertebral disc at the Department of Acupuncture and Moxibustion Medicine at the Daejeon Korean Medicine Hospital from April 14th to August 25th, 2019, this study retrospectively analyzed the medical records of 31 patients who underwent nonsurgical spinal decompression treatment and traditional Korean medicine (assigned to Group A) and another 31 patients who received typical traditional Korean medicine alone (assigned to Group B). The clinical data were analyzed using IBM SPSS Version 23.0. Results: No statistically significant differences appeared in terms of sociodemographic, condition, and therapeutic characteristics, except whether the patient received Western medicine treatment, before or after a treatment with traditional Korean medicine. Group A exhibited higher variations in numeric rating scale, EuroQol- 5 dimension and EuroQol visual analogue scale scores compared to Group B as determined by independent sample t test and analysis of covariance. In addition, the satisfaction score of Group A was higher than that of Group B The result of cross analysis revealed that desire for continued treatment in Group A was higher than that of Group B. Conclusion: This retrospective observational study showed that the patients with nonsurgical spinal decompression treatment reported a greater reduction in pain, improved quality of life and satisfaction than patients receiving typical traditional Korean medicine.

Newly Developed Settlement Prediction Method on Soft Soils with Subsequent Surcharge Change (성토고 변화를 고려한 새로운 연약 지반 침하 예측 기법)

  • Chun, Sung-Ho;Kim, Han-Saem;Yune, Chan-Young;Chung, Choong-Ki
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.5C
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    • pp.155-162
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    • 2011
  • Settlement prediction based on field monitored data, which is used to control subsequent surcharges, is very important in construction management for soft ground improvement with the preloading method. Observational settlement prediction methods, which are suggested for an instantaneous loading, have been widely used in fields. However, they have difficulties in the settlement prediction with subsequent surcharge change. In this paper, a simple method to predict the settlement with subsequent surcharge change is suggested. The suggested method adopts assumptions to simplify the complex field condition and utilizes observational methods. The suggested method is applied to a large consolidation test result, FDM analysis results, and field monitored settlement data to confirm its practicability. From the applications, the suggested method produces reasonable prediction results with various subsequent surcharge changes.

Application of a Statistical Interpolation Method to Correct Extreme Values in High-Resolution Gridded Climate Variables (고해상도 격자 기후자료 내 이상 기후변수 수정을 위한 통계적 보간법 적용)

  • Jeong, Yeo min;Eum, Hyung-Il
    • Journal of Climate Change Research
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    • v.6 no.4
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    • pp.331-344
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    • 2015
  • A long-term gridded historical data at 3 km spatial resolution has been generated for practical regional applications such as hydrologic modelling. However, overly high or low values have been found at some grid points where complex topography or sparse observational network exist. In this study, the Inverse Distance Weighting (IDW) method was applied to properly smooth the overly predicted values of Improved GIS-based Regression Model (IGISRM), called the IDW-IGISRM grid data, at the same resolution for daily precipitation, maximum temperature and minimum temperature from 2001 to 2010 over South Korea. We tested various effective distances in the IDW method to detect an optimal distance that provides the highest performance. IDW-IGISRM was compared with IGISRM to evaluate the effectiveness of IDW-IGISRM with regard to spatial patterns, and quantitative performance metrics over 243 AWS observational points and four selected stations showing the largest biases. Regarding the spatial pattern, IDW-IGISRM reduced irrational overly predicted values, i. e. producing smoother spatial maps that IGISRM for all variables. In addition, all quantitative performance metrics were improved by IDW-IGISRM; correlation coefficient (CC), Index Of Agreement (IOA) increase up to 11.2% and 2.0%, respectively. Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) were also reduced up to 5.4% and 15.2% respectively. At the selected four stations, this study demonstrated that the improvement was more considerable. These results indicate that IDW-IGISRM can improve the predictive performance of IGISRM, consequently providing more reliable high-resolution gridded data for assessment, adaptation, and vulnerability studies of climate change impacts.

Analysis of future flood inundation change in the Tonle Sap basin under a climate change scenario

  • Lee, Dae Eop;Jung, Sung Ho;Yeon, Min Ho;Lee, Gi Ha
    • Korean Journal of Agricultural Science
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    • v.48 no.3
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    • pp.433-446
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    • 2021
  • In this study, the future flood inundation changes under a climate change were simulated in the Tonle Sap basin in Cambodia, one of the countries with high vulnerability to climate change. For the flood inundation simulation using the rainfall-runoff-inundation (RRI) model, globally available geological data (digital elevation model [DEM]; hydrological data and maps based on Shuttle elevation derivatives [HydroSHED]; land cover: Global land cover facility-moderate resolution imaging spectroradiometer [GLCF-MODIS]), rainfall data (Asian precipitation-highly-resolved observational data integration towards evaluation [APHRODITE]), climate change scenario (HadGEM3-RA), and observational water level (Kratie, Koh Khel, Neak Luong st.) were constructed. The future runoff from the Kratie station, the upper boundary condition of the RRI model, was constructed to be predicted using the long short-term memory (LSTM) model. Based on the results predicted by the LSTM model, a total of 4 cases were selected (representative concentration pathway [RCP] 4.5: 2035, 2075; RCP 8.5: 2051, 2072) with the largest annual average runoff by period and scenario. The results of the analysis of the future flood inundation in the Tonle Sap basin were compared with the results of previous studies. Unlike in the past, when the change in the depth of inundation changed to a range of about 1 to 10 meters during the 1997 - 2005 period, it occurred in a range of about 5 to 9 meters during the future period. The results show that in the future RCP 4.5 and 8.5 scenarios, the variability of discharge is reduced compared to the past and that climate change could change the runoff patterns of the Tonle Sap basin.

A Study on the Causes of Child Loss through Behavioral Analysis of Customers Accompanied with Children in Urban Entertainment Centers (복합상업시설에서의 아동 동반 고객 행태분석을 통한 미아 발생원인 고찰)

  • Choi, Jaepil;Choi, Soyoung;Yoo, Saewon;Han, Gyu Bin
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.36 no.1
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    • pp.49-60
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    • 2020
  • Although the number of child loss in commercial facilities has been growing recently, the prevention method for child loss are still lacking in the environmental aspect. This research examines the causes of lost child in behavioral aspects in order to develop a guideline to prevent child loss in U.E.C. The observational study on the behaviors of guardians and children was conducted in the U.E.C that is visited by many customers accompanied with children. Then the results of the observational study were marked on the behavioral maps. After analyzing the behavioral maps, the causes of child loss were determined by classifying into behaviors by age and behaviors by functional space. As a result, when guardian is unable to pay attention to child by doing something else such as making a purchase, or an inquiry, child may lose guardian by going towards the interesting factors or playing around. Moreover, if the spaces related to children are located at the node with high pedestrian density and open structure or the environment that is hard for the guardians to watch over their children, it will be easy for guardians to be inattentive to their children, and get separated from each other.

Functional Gastrointestinal Disorders in Neonates and Toddlers According to the Rome IV Criteria: A Systematic Review and Meta-Analysis

  • Velasco-Benitez, Carlos Alberto;Collazos-Saa, Laura Isabel;Garcia-Perdomo, Herney Andres
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.25 no.5
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    • pp.376-386
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    • 2022
  • Functional gastrointestinal disorders (FGIDs) are classified as a combination of persistent gastrointestinal symptoms. The Rome IV criteria can elucidate several factors in the pathogenesis of FGIDs. The frequency of FGIDs can differ between clinical and nonclinical settings and between geographic regions. To determine the global prevalence of FGIDs in neonates and toddlers according to the Rome IV criteria. We included cohort and descriptive observational studies reporting the prevalence of FGIDs according to the Rome IV criteria in children aged 0-48 months. We searched the Medline, Embase, Lilacs, and CENTRAL databases from May 2016 to the present day. Furthermore, unpublished literature was searched to supplement this information. The Strengthening the Reporting of Observational Studies in Epidemiology statement was used to evaluate the risk of bias. A meta-analysis of the proportions was performed using MetaProp in R. The results are reported in forest plots. We identified and analyzed 15 studies comprising 48,325 participants. Six studies were conducted in Europe, three in Latin America, two in North America, and four in Asia. Most participants were 12-48 months old (61.0%) and were recruited from the community. The global prevalence of FGIDs was 22.0% (95% confidence interval, 15-31%). The most common disorder was functional constipation (9.0%), followed by infant regurgitation syndrome (8.0%). Its prevalence was higher in the Americas (28.0%). FGIDs, as defined by the Rome IV criteria, are present in 22% of children, and the most common primary disorder is functional constipation. A higher prevalence of FGIDs has been reported in America.