• 제목/요약/키워드: Stability Rating Test

검색결과 44건 처리시간 0.022초

Designing of the Beheshtabad water transmission tunnel based on the hybrid empirical method

  • Mohammad Rezaei;Hazhar Habibi
    • Structural Engineering and Mechanics
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    • 제86권5호
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    • pp.621-633
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    • 2023
  • Stability analysis and support system estimation of the Beheshtabad water transmission tunnel is investigated in this research. A combination approach based on the rock mass rating (RMR) and rock mass quality index (Q) is used for this purpose. In the first step, 40 datasets related to the petrological, structural, hydrological, physical, and mechanical properties of tunnel host rocks are measured in the field and laboratory. Then, RMR, Q, and height of influenced zone above the tunnel roof are computed and sorted into five general groups to analyze the tunnel stability and determine its support system. Accordingly, tunnel stand-up time, rock load, and required support system are estimated for five sorted rock groups. In addition, various empirical relations between RMR and Q i.e., linear, exponential, logarithmic, and power functions are developed using the analysis of variance (ANOVA). Based on the significance level (sig.), determination coefficient (R2) and Fisher-test (F) indices, power and logarithmic equations are proposed as the optimum relations between RMR and Q. To validate the proposed relations, their results are compared with the results of previous similar equations by using the variance account for (VAF), root mean square error (RMSE), mean absolute percentage error (MAPE) and mean absolute error (MAE) indices. Comparison results showed that the accuracy of proposed RMR-Q relations is better than the previous similar relations and their outputs are more consistent with actual data. Therefore, they can be practically utilized in designing the tunneling projects with an acceptable level of accuracy and reliability.

보은군 회북면 오동리 2지구 암반 절개면의 붕괴원인 고찰 (Investigation on Rock Slope Failure in Odong 2 area, Boeun-Gun)

  • 구호본;백용;김규한;이종현
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 가을 학술발표회 논문집
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    • pp.535-542
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    • 2000
  • The investigated cut-slope is located in Odong-Ri, Hoebuk-Myun, Boeun-Gun and composed of quartzite and phyllitic rocks (approximately 80 meters in length and 25 meters in height). During the investigation, the groundwater which was inferred to the natural pipe of slope was continuously flowing in the upper part of slope. The investigation for discontinuity properties in this area was carried out to decide the rock mass rating and strength parameters. To analyze the stability of cut-slope, lower equal-area hemisphere projection method was used. And laboratory test was done to evaluate engineering properties of soil which was sampled in the non-failure and failure area The inferred causes of cut-slope failure are the geometric relationship between the orientation of cut-slope and geological structures such as joints, faults which is distributed in the slope. And direct cause of failure is the increase of water content due to the heavy rainfall.

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요각통으로 입원한 요추부 후만곡 환자 1례에 대한 증례보고 (One case on Lumbar Kyphosis with Complaining Lower Back Pain and Low Extremity Pain)

  • 권혁준;김주원;류기준;김호준;이명종
    • 척추신경추나의학회지
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    • 제4권2호
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    • pp.109-120
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    • 2009
  • Objectives : We already know the importance of stability and flexibility on the vertebra. It is important to keep the lumbar lordosis for stability and flexibility. We hope to reduce lower back pain and low extremity pain by changing the angle of the Lumbar Kyphosis through conservative treatment. We have evaluated the effect of conservative treatment with Saamchimbeop Pejeonggyeok by experimenting one patient suffering from Lumbar Kyphosis with lower back pain and low extremity pain. Methods : One patients were diagnosed as Lumbar Kyphosis through X-ray examination. We used conservative treatment, especially Pejeonggyeok Treatment to the patients and measured NRS((Numerical Rating Scale), rating scale for low back pain, low extremity pain and SLR(Straight Leg Raising) test and walking time in whole term of admission, and we also measured flexion, extension angle and lumbar kyphosis using lumbar x-ray lateral view after diganosing by Lumbar Kyphosis. Results and Conclusions : After treating conservative therapy, We figured out that the patient were on the mend, and we found out the angle change in flexion, extension and lumbar Kyphosis. These results suggest that Pejeonggyeok Treatment were effective to improved Lumbar Kyphosis and reduced the low back pain.

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총의치 사용에 대한 환자와 술자간 평가 비교 (Comparison between denture wearer's evaluation and clinician's rating for complete denture)

  • 변진수;허윤혁;조리라;박찬진
    • 대한치과보철학회지
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    • 제54권4호
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    • pp.364-369
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    • 2016
  • 목적: 총의치를 사용하고 있는 무치악 환자에서 의치 사용에 대한 환자의 평가와 술자간의 평가를 비교하고자 하였다. 대상 및 방법: 의치를 사용한지 최소 1년 이상 경과된 총의치 장착자 중 43명의 환자가 정기검진에 응하였다. 환자에 관한 여러 정보를 얻기 위해 다양한 문헌에서 얻은 자료를 토대로 설문지를 개발하고 술자의 객관적인 평가간 일치도를 분석하였다. 술자의 평가 사항으로는 유지, 안정, 교합과 같은 기능적 항목과 의치의 상태를 포함한다. Friedman test와 Cohen's Kappa값을 이용하여 통계학적인 분석을 시행하였다. 결과: 의치 장착자의 평가와 술자의 평가 간에는 약하거나 약간의 차이가 있다. 상악 의치보다는 하악의치에서 차이가 더 크게 나타났으며 심미와 저작은 중등도의 차이가 있었다. 결론: 의치에 대한 환자의 주관적, 술자의 객관적인 평가는 일치하지 않으나 큰 차이를 보이지 않는다.

다분류 SVM을 이용한 DEA기반 벤처기업 효율성등급 예측모형 (The Prediction of DEA based Efficiency Rating for Venture Business Using Multi-class SVM)

  • 박지영;홍태호
    • Asia pacific journal of information systems
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    • 제19권2호
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    • pp.139-155
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    • 2009
  • For the last few decades, many studies have tried to explore and unveil venture companies' success factors and unique features in order to identify the sources of such companies' competitive advantages over their rivals. Such venture companies have shown tendency to give high returns for investors generally making the best use of information technology. For this reason, many venture companies are keen on attracting avid investors' attention. Investors generally make their investment decisions by carefully examining the evaluation criteria of the alternatives. To them, credit rating information provided by international rating agencies, such as Standard and Poor's, Moody's and Fitch is crucial source as to such pivotal concerns as companies stability, growth, and risk status. But these types of information are generated only for the companies issuing corporate bonds, not venture companies. Therefore, this study proposes a method for evaluating venture businesses by presenting our recent empirical results using financial data of Korean venture companies listed on KOSDAQ in Korea exchange. In addition, this paper used multi-class SVM for the prediction of DEA-based efficiency rating for venture businesses, which was derived from our proposed method. Our approach sheds light on ways to locate efficient companies generating high level of profits. Above all, in determining effective ways to evaluate a venture firm's efficiency, it is important to understand the major contributing factors of such efficiency. Therefore, this paper is constructed on the basis of following two ideas to classify which companies are more efficient venture companies: i) making DEA based multi-class rating for sample companies and ii) developing multi-class SVM-based efficiency prediction model for classifying all companies. First, the Data Envelopment Analysis(DEA) is a non-parametric multiple input-output efficiency technique that measures the relative efficiency of decision making units(DMUs) using a linear programming based model. It is non-parametric because it requires no assumption on the shape or parameters of the underlying production function. DEA has been already widely applied for evaluating the relative efficiency of DMUs. Recently, a number of DEA based studies have evaluated the efficiency of various types of companies, such as internet companies and venture companies. It has been also applied to corporate credit ratings. In this study we utilized DEA for sorting venture companies by efficiency based ratings. The Support Vector Machine(SVM), on the other hand, is a popular technique for solving data classification problems. In this paper, we employed SVM to classify the efficiency ratings in IT venture companies according to the results of DEA. The SVM method was first developed by Vapnik (1995). As one of many machine learning techniques, SVM is based on a statistical theory. Thus far, the method has shown good performances especially in generalizing capacity in classification tasks, resulting in numerous applications in many areas of business, SVM is basically the algorithm that finds the maximum margin hyperplane, which is the maximum separation between classes. According to this method, support vectors are the closest to the maximum margin hyperplane. If it is impossible to classify, we can use the kernel function. In the case of nonlinear class boundaries, we can transform the inputs into a high-dimensional feature space, This is the original input space and is mapped into a high-dimensional dot-product space. Many studies applied SVM to the prediction of bankruptcy, the forecast a financial time series, and the problem of estimating credit rating, In this study we employed SVM for developing data mining-based efficiency prediction model. We used the Gaussian radial function as a kernel function of SVM. In multi-class SVM, we adopted one-against-one approach between binary classification method and two all-together methods, proposed by Weston and Watkins(1999) and Crammer and Singer(2000), respectively. In this research, we used corporate information of 154 companies listed on KOSDAQ market in Korea exchange. We obtained companies' financial information of 2005 from the KIS(Korea Information Service, Inc.). Using this data, we made multi-class rating with DEA efficiency and built multi-class prediction model based data mining. Among three manners of multi-classification, the hit ratio of the Weston and Watkins method is the best in the test data set. In multi classification problems as efficiency ratings of venture business, it is very useful for investors to know the class with errors, one class difference, when it is difficult to find out the accurate class in the actual market. So we presented accuracy results within 1-class errors, and the Weston and Watkins method showed 85.7% accuracy in our test samples. We conclude that the DEA based multi-class approach in venture business generates more information than the binary classification problem, notwithstanding its efficiency level. We believe this model can help investors in decision making as it provides a reliably tool to evaluate venture companies in the financial domain. For the future research, we perceive the need to enhance such areas as the variable selection process, the parameter selection of kernel function, the generalization, and the sample size of multi-class.

대학적응력 검사도구 척도 개발과 양호도 검증 (The Development of Scales on Rating College Students' Adaptability and the Analysis of Technical Quality)

  • 김수연
    • 한국인터넷방송통신학회논문지
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    • 제16권6호
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    • pp.295-303
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    • 2016
  • 본 연구는 대학생의 대학적응력에 영향을 미치는 요인을 구성하고, 이를 진단하기 위한 대학적응력 척도 개발의 절차를 소개하며 검사도구의 양호도를 검증하였다. 이 도구는 3단계의 척도 추출 과정 및 6단계의 문항 추출 과정을 거쳐 제작하였다. 추출 결과, 학문적 통합성, 사회적 통합성, 정서적 안정성, 진로정체성, 학업여건 안정성, 교수와의 관계, 교육서비스 만족도, 대학교육 만족도 등 8개 척도, 142개 문항 구성을 통해 대학적응력을 측정하였다. 4개 대학 1,959명의 대학생을 대상으로 검사를 실시한 도구의 양호도 분석 결과는 다음과 같다. 첫째, 문항내적 일관성 전체 신뢰도 계수 Cronbach's ${\alpha}$는 .965, 범위는 .742~.937로써 신뢰도가 매우 높다. 둘째, 개별 문항의 양호도를 평가하기 위하여 각 척도 및 하위요인별로 문항 점수와 총점 간 상관계수에 의한 문항 변별도를 구했으며, 평균은 .147~.841이다. 셋째, 확인적 요인분석에 따른 구인타당도 검증 결과, CFA모델의 RMSEA = .08~.09이고, 모든 부합도지수가 기준에 양호하게 부합함으로써 각 척도에 속하는 문항들이 측정하고자 하는 특성을 타당하게 측정하고 있는 것으로 나타났다. 넷째, 척도별 대학적응경향성과 중도탈락경향성 점수 차이에 기초한 공인타당도 검증 결과, 학업여건 안정성을 제외한 모든 척도에서 유의수준 .05수준에서 통계적으로 유의한 차이가 있음이 확인되었다. 연구결과, 대학적응력 진단 도구는 대학생의 대학적응경향성과 중도탈락경향성을 타당하게 예측하는 도구로 확인되었다.

Long-term stability of dentoalveolar, skeletal, and soft tissue changes after non-extraction treatment with a self-ligating system

  • Basciftci, Faruk Ayhan;Akin, Mehmet;Ileri, Zehra;Bayram, Sinem
    • 대한치과교정학회지
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    • 제44권3호
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    • pp.119-127
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    • 2014
  • Objective: To evaluate the long-term effects of self-ligating brackets (SLBs) on transverse dimensions of arches and skeletal and soft tissues and to quantitatively evaluate the treatment outcome after non-extraction treatment with SLBs. Methods: The sample consisted of 24 (18 female and six male) subjects, with a mean age of $14.23{\pm}2.19$ years, who received treatment with the Damon$^{(R)}$3 appliances. Complete records including cephalometric radiographs and plaster models were obtained before treatment (T1), immediately after treatment (T2), six months after treatment (T3), and two years (T4) after treatment. Digital study models were generated. Twenty lateral cephalometric, six frontal cephalometric, and eight dental cast measurements were examined. The Peer Assessment Rating index was used to measure the treatment outcome. The Wilcoxon test was applied for statistical analysis of the changes. Results: There were significant increases in all transverse dental cast measurements with active treatment. There was some significant relapse in the long term, particularly in maxillary width (p < 0.05). Statistically significant increases were found in nasal (p < 0.001), maxillary base, upper molar, lower intercanine, and antigonial (p < 0.05) widths in T1-T2. Lower incisors were proclined and protruded in T1-T2. Conclusions: SLBs correct crowding by mechanisms involving incisor proclination and protrusion and expansion of the dental arches, without induction of clinically significant changes in hard and soft tissues of the face.

추력 30톤급 액체산소/케로신 로켓엔진 연소장치 개발(I)-연소기 (Development of 30-Tonf LOx/Kerosene Rocket Engine Combustion Devices(I) - Combustion Chamber)

  • 최환석;한영민;김영목;조광래
    • 한국항공우주학회지
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    • 제37권10호
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    • pp.1027-1037
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    • 2009
  • 우주발사체용 30톤급 액체로켓엔진 재생냉각 연소기 개발과정에 관하여 기술하였다. 이중추진제 동축 와류형 분사기 개발에서부터 시작하여 축소형 연소기를 통해 요소기술을 검증하고 개발된 기술을 실물형 연소기에 적용하였다. 총 5기의 실물형 연소기 개발시제를 사용하여 점화성능, 연소안정성, 연소성능, 냉각성능, 내구성 등의 검증을 수행하였다. 이 과정에서 총 46회의 실물형 연소기 연소시험을 실시하였고 이 중 23회는 기폭장치를 이용한 연소안정성 평가시험을 병행하였다. 시험 결과 30톤급 재생냉각 연소기는 연소 성능 및 연소안정성 요구사항을 모두 만족시켜 단품 개발이 성공적으로 완료된 것으로 평가하였다.

상관관계를 반영한 신용등급 계량화 검정기법 연구 (Study on the validation methods of calibration considering correlations)

  • 김은나;하정철
    • Journal of the Korean Data and Information Science Society
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    • 제21권3호
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    • pp.407-417
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    • 2010
  • 신BIS협약에서는 자본적정성 규제에 있어서 자율성 확대를 위해 내부등급시스템을 허용하였고, 이에 따라 시스템의 적합성 검증의 중요성을 더욱 강조하게 되었다. 적합성검증은 양적 질적 검증으로 나뉘며 이 때 양적 검증은 변별력, 안정성, 등급의 계량화로 구별된다. 본 논문에서는 양적 검증의 등급의 계량화 중 신용등급 변화 검정기법에 대하여 연구하려고 한다. 등급의 계량화 검정은 등급별로 추정된 부도율과 실제 부도율과의 차이를 검정하는 방법으로 한 시점에 대한 검정으로 이항검정과 카이제곱검정, Brier score, 신호등 검정이 있고, 여러 시점의 정확성을 검증하는 방법으로 정규성 검정, 확장된 신호등 검정이 있다. 신용평가시스템의 정확성을 높이고, 현실 상황에 반영이 가능하려면 상관관계를 고려하지 않을 수 없다. 본 논문에서는 부도상관관계를 고려한 확장된 신호등 검정을 제안하고자 한다.

유기변성 LDH를 사용한 난연 ABS 나노복합재료의 열적 및 기계적 물성 (Thermal and Mechanical Properties of Flame Retardant ABS Nanocomposites Containing Organo-Modified Layered Double Hydoxide)

  • 김석준
    • Elastomers and Composites
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    • 제43권4호
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    • pp.241-252
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    • 2008
  • 올레인산으로 유기변성된 ZnAl-LDH(SO-ZnAl LDH)를 합성하여 브롬화 에폭시 수지(BER) 및 산화안티몬을 포함하는 난연 ABS 컴파운드에 첨가하였다. 난연 ABS 컴파운드는 동일방향으로 회전하는 이축압출기를 통해 제조되었고 난연성 및 기계적 성질을 측정하기 위한 시편으로 사출성형 되었다. ABS 나노복합재료의 XRD 패턴에서는 피크가 나타나지 않았다. SOZnAl LDH를 포함하는 난연 ABS 나노복합재료는 TGA 시험 결과 향상된 내열성을 보였다. 그러나, 난연 ABS 나노복합재료들은 UL 94 수직시험(1.6 mm 두께)시 등급을 얻지 못했다. BER를 1.5 wt% 이상 더 첨가한 경우들에서만 UL 94 V0 등급을 얻을 수 있었다. SO-ZnAl LDH의 첨가량에 비례하여 난연 ABS 나노복합재료의 노치드 아이조드 충격강도, 인장탄성률 및 신율은 증가하였으나 유동지수는 감소하였다.