• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 The 8th Asian Symposium on Precision Forging ASPF
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• pp.94-106
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• 2003

In recent years, the production value of Taiwanese mold and die industries have reached to a high peak in 1998, in amount of NT 604 hundred million dollars. But in recent years production value are going down year by year, till year of 2001 the production value have down to NT 394 hundred million dollars. Its main reason might be the major product were following in medium and low price category, the high accuracy and high cost mold and die still rely on import aboard. Therefore how to made the related technical database system on various field to provide the industry user to promote industries competition ability in mold and die is really urgent matter at this moment. In this research, we will offer how to apply the Visual Basic program language to edit a set of more perfect database system of mold and die material selection. At the present time, we have constructed complete Knowledge-Base-System of intelligence for forging mold and die material, the most related data from the existed data, the others are through our additional experimental results. By using this system by the user can got the related and need data easily, we hope it will reduce designing time and cost for mold and die.

• Geomechanics and Engineering
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• 제31권3호
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• pp.265-279
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• 2022

Tunnel convergence prediction is essential for the safe construction and design of tunnels. This study proposes five machine learning models of deep neural network (DNN), K-nearest neighbors (KNN), Gaussian process regression (GPR), support vector regression (SVR), and decision trees (DT) to predict the convergence phenomenon during or shortly after the excavation of tunnels. In this respect, a database including 650 datasets (440 for training, 110 for validation, and 100 for test) was gathered from the previously constructed tunnels. In the database, 12 effective parameters on the tunnel convergence and a target of tunnel wall convergence were considered. Both 5-fold and hold-out cross validation methods were used to analyze the predicted outcomes in the ML models. Finally, the DNN method was proposed as the most robust model. Also, to assess each parameter's contribution to the prediction problem, the backward selection method was used. The results showed that the highest and lowest impact parameters for tunnel convergence are tunnel depth and tunnel width, respectively.

• 자원환경지질
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• 제31권6호
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• pp.557-567
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• 1998

In order to utilize the data obtained during the deep-sea resources exploration program, the analysis of data structure and database were conducted to develop an appropriate data operating system called Deep-sea Database System. The Relation Data Base Management System, RDBMS, was chosen as a data managing system and the MS Access$^{TM}$ as a DB engine, and the MapInfo$^{TM}$ software as GIS tools. Problems in networking and security were detected and solved during the operation test. Accordingly, development of standardized operative procedure was proposed in obtaining raw data. This proposal will also be reflected in the subsequent phase of the deep-sea program. The Deep-sea Database System could be applied to the selection of potential mining sites and the estimation of economical efficiency over th KODOS (Korea Deep Ocean Study) region. It is also expected that this system might improve the efficiency of detail survey and help in the relinquishment process as a fulfillment of the obligation as a pioneer investor.

• 한국컴퓨터정보학회논문지
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• 제7권4호
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• pp.168-173
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• 2002

인터넷 서비스의 급속한 발전으로 전자 상거래의 이용규모가 해마다 증가하고 있다. 이에 따라 소프트웨어 개발비용을 줄이고 자료구축을 용이하게 함으로서 전자상거래의 활성화를 유도하는 방안이 요구된다. 인터넷 기반의 분산기술을 적용한 웹 서비스는 소프트웨어의 공유를 통해 개발비용을 줄이는 기반을 제공한다. 공유된 소프트웨어는 동일 자료에 접근하게 함으로서 서로 다른 사이트에서 공동의 자료를 참조할 수 있게 한다. 본 고에서는 전자상거래를 위한 데이터베이스 처리 모듈을 웹 서비스로 설계 및 구현함으로서 전자상거래 사이트 개발을 용이하게 하고 데이터베이스를 공유할 수 있도록 하였다. 구현된 웹 서비스는 개발자간에 자료의 선택 수정 추가 삭제 및 검색 기능을 지원하며, 서로 다른 사이트간에 상품정보의 공동 활용이 가능함을 보였다.

• 한국GIS학회:학술대회논문집
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• 한국GIS학회 2003년도 공동 춘계학술대회 논문집
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• pp.65-70
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• 2003

The weight-of-evidence model one of the Bayesian probability model was applied to the task of evaluating landslide susceptibility using GIS. Using the location of the landslides and spatial database such as topography, soil, forest, geology, land use and lineament, the weight-of-evidence model was applied to calculate each factor's rating at Boun area in Korea where suffered substantial landslide damage fellowing heavy rain in 1998, The factors are slope, aspect and curvature from the topographic database, soil texture, soil material, soil drainage, soil effective thickness, and topographic type from the soil database, forest type, timber diameter, timber age and forest density from the forest map, lithology from the geological database, land use from Landsat TM satellite image and lineament from IRS satellite image. Tests of conditional independence were performed for the selection of the factors, allowing the 43 combinations of factors to be analyzed. For the analysis, the contrast value, W$\^$＋/and W$\^$-/, as each factor's rating, were overlaid to map laudslide susceptibility. The results of the analysis were validated using the observed landslide locations, and among the combinations, the combination of slope, curvature, topographic, timber diameter, geology and lineament show the best results. The results can be used for hazard prevention and planning land use and construction

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2007년도 가을 학술발표논문집 Vol.34 No.2 (C)
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• pp.78-83
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• 2007

최근 상황정보 관리의 범위가 단일 도메인에서 다중 도메인으로 확장되면서 사용자의 상황정보는 사용자가 위치하고 있는 도메인뿐만 아니라 여러 도메인에 연관되게 되고 그로 인해 제공될 수 있는 유비쿼터스 컴퓨팅 서비스가 점점 다양해졌다. 다중도메인 환경에서 같은 종류의 상황정보는 다수의 로컬 상황정보 관리자에 의해 제공될 수 있기 때문에, 해당 상황정보에 대한 적합한 로컬 상황정보 관리자가 글로벌 상황정보관리자에 의해 선택되어야 한다. 본 논문에서 우리는 하나의 글로벌 상황정보 관리자와 여러개의 로컬 상황정보 관리자로 구성된 연합 구조를 제안하고, 연합 상황정보 처리를 위해 상황정보 제공자 선택 문제에 대해 논하고 선택 방법을 제안한다. 또한 연합 상황정보 관리에서 어떻게 이 선택 방법이 상황추론의 결과를 향상시키는지 보여준다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.210-215
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• 1998

To design a space frame structure by the conventional method is not easy in practical sense since it is generally a three-dimensional complicated form, and stability and nonlinear problems are not easily checked in the design process. This paper describes two modules, the Model Generator which is based on PATRAN user interface that enables users to generate a complicated finite element model; the Optimum Design Module which analyzes output results of analysis program, and designs members of a space frame. The Model Generator is based on PCL while C++ language is used in the Optimum Design Module. Structural analysis is performed by using ABAQUS. All of these modules constitute Space Frame Integrated Design System. The Core of the system is PATRAN database, in which the Model Generator creates information of a finite element model. Then, PATRAN creates input files needed for the analysis program from the information of the finite element model in the database, and in turn, imports output results of analysis program to the database. Finally, the Optimum Design Module processes member grouping of a space frame based on the output results, and performs optimal member selection of a space frame. This process is repeated until the desired optimum structural members are obtained.

• 한국지반공학회논문집
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• 제30권8호
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• pp.25-37
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• 2014

국내 외 하중저항계수설계법의 저항계수 보정 시 수집된 데이터베이스의 신뢰성을 향상시키기 위하여 저항편향계수 산정 단계에서 저항편향치의 ${\pm}2{\sigma}$ 범위의 데이터만을 선택하거나 가정된 확률분포 검정을 만족하도록 꼬리(tail)부분의 데이터를 제거하는 방법을 적용하고 있다. 그러나 이들 방법에서는 데이터베이스 내에 우연히 포함된 저품질의 데이터를 확인할 수 없는 단점이 발견되었다. 본 연구에서는 정재하시험의 품질, 원지반의 공학적 특성, 쇄석다짐말뚝의 제원 등의 품질기준을 이용하여 데이터베이스 구축 단계에서 수행할 수 있는 품질평가법을 제안하였으며, 국내 외 문헌 및 정재하시험 보고서로부터 65개소의 정재하시험 데이터를 수집하여 데이터베이스의 구축 및 품질평가를 수행하였다. 데이터베이스의 품질 평가 상태에 따른 저항편향계수와 변동계수, 저항계수를 비교한 결과, 기존의 데이터베이스 처리과정과 품질평가법을 병행할 경우에 저항편향계수의 불확실성이 감소되며, 신뢰도 높은 LRFD 저항계수 보정에 효과적인 것으로 판단된다.

• Journal of Preventive Medicine and Public Health
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• 제42권4호
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• pp.267-273
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• 2009

Objectives : To compare the performance of three comorbidity measurements (Charlson comorbidity index, Elixhauser s comorbidity and comorbidity selection) with the effect of different comorbidity lookback periods when predicting in-hospital mortality for patients who underwent percutaneous coronary intervention. Methods : This was a retrospective study on patients aged 40 years and older who underwent percutaneous coronary intervention. To distinguish comorbidity from complications, the records of diagnosis were drawn from the National Health Insurance Database excluding diagnosis that admitted to the hospital. C-statistic values were used as measures for in comparing the predictability of comorbidity measures with lookback period, and a bootstrapping procedure with 1,000 replications was done to determine approximate 95% confidence interval. Results : Of the 61,815 patients included in this study, the mean age was 63.3 years (standard deviation: ${\pm}$10.2) and 64.8% of the population was male. Among them, 1,598 2.6%) had died in hospital. While the predictive ability of the Elixhauser's comorbidity and comorbidity selection was better than that of the Charlson comorbidity index, there was no significant difference among the three comorbidity measurements. Although the prevalence of comorbidity increased in 3 years of lookback periods, there was no significant improvement compared to 1 year of a lookback period. Conclusions : In a health outcome study for patients who underwent percutaneous coronary intervention using National Health Insurance Database, the Charlson comorbidity index was easy to apply without significant difference in predictability compared to the other methods. The one year of observation period was adequate to adjust the comorbidity. Further work to select adequate comorbidity measurements and lookback periods on other diseases and procedures are needed.

• Korean Journal of Acupuncture
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• 제38권2호
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• pp.100-109
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• 2021

Objectives : Source acupoint is one of the representative acupoints to treat various diseases in each meridian. We aimed to identify the patterns of selection of Source acupoints and their associations with diseases using clinical trials data. Methods : We extracted the frequency of Source acupoints across 30 diseases from clinical trials database. Acupuncture treatment regimens were retrieved from the Cochrane Database of Systematic Reviews. The frequency of Source acupoint use was calculated as the number of studies using a certain acupoint divided by the total number of included studies. Using hierarchical clustering and multidimensional scaling, the characteristics of Source acupoints were analyzed based on the similarity of the relationships between the Source acupoints and the diseases. Results : A total of 421 clinical trials were included for this analysis. LR3, HT7, KI3, and LI4 acupoints were most frequently used for the treatment of 30 diseases. Cluster analysis showed that LR3 and LI4 acupoints were grouped together and HT7 and KI3 acupoints were grouped together. Multidimensional scaling revealed that LR3, LI4, HT7, and KI3 acupoints have intrinsic properties in the two-dimensional space. Conclusions : The present study identified the selection patterns of the Source acupoints using clinical trials data. Our finding will provide the understanding of the characteristics of Source acupoints.