Reliability of Hip Migration Index in Children with Cerebral Palsy: The Classic and Modifi ed Methods

Sun Mi Kim,박은숙,Eun Geol Sim,Seong Gyu Lim 대한재활의학회 2012 Annals of Rehabilitation Medicine Vol.36 No.1

Objective To determine reliability and clinical use of two methods of migration index (MI) in CP patients with or without hip dysplasia. Method The materials included radiographs of 200 hips of children with cerebral palsy. Conventional anteroposterior radiographs of the pelvis were taken with the child in the supine position with standardized methods. Two rehabilitation doctors measured the migration index using two methods. In the classic method,the lateral margin of the acetabular roof was used as a landmark and in the modifi ed method the lateral margin of the sourcil was used as a landmark. Each rater measured the migration index at three separate times with a time interval of at least one week. Intraclass correlation (ICC) was used to test the inter- and intra-rater reliability. Results MI shows excellent intra-rater reliability in both the classic and modified methods, but the inter-rater reliability was higher in the classic method than in the modified method. When categorized according to the sourcil classifi cation, inter-rater reliability was higher in the normal sourcil type and lower in the dysplastic sourcil types. Conclusion Generally, the classic method showed higher reliability than the modifi ed method, even though the reliability of the MI measurement was relatively high with both methods. Objective To determine reliability and clinical use of two methods of migration index (MI) in CP patients with or without hip dysplasia. Method The materials included radiographs of 200 hips of children with cerebral palsy. Conventional anteroposterior radiographs of the pelvis were taken with the child in the supine position with standardized methods. Two rehabilitation doctors measured the migration index using two methods. In the classic method,the lateral margin of the acetabular roof was used as a landmark and in the modifi ed method the lateral margin of the sourcil was used as a landmark. Each rater measured the migration index at three separate times with a time interval of at least one week. Intraclass correlation (ICC) was used to test the inter- and intra-rater reliability. Results MI shows excellent intra-rater reliability in both the classic and modified methods, but the inter-rater reliability was higher in the classic method than in the modified method. When categorized according to the sourcil classifi cation, inter-rater reliability was higher in the normal sourcil type and lower in the dysplastic sourcil types. Conclusion Generally, the classic method showed higher reliability than the modifi ed method, even though the reliability of the MI measurement was relatively high with both methods.

신용평가사의 신용등급측정의 신뢰성에 관한 연구 : 감리지적기업을 중심으로

고윤성,권태웅,김재승 韓國公認會計士會 2013 회계·세무와 감사 연구 Vol.55 No.1

신용평가사에서 제공하는 신용지표는 기업평가, 위험관리, 여신업무, 자본조달 및 투자 등 매우 광범위한 분야에서 활용되고 있으며, 최근의 경제위기 상황에서는 그 중요성이 더욱 증대되고 있다. 따라서 신용평가정보가 정보비대칭을 완하시키고, 자본시장의 초석이 되기 위해서 그 무엇보다도 신용정보가 신뢰성을 가지고 있어야 할 것이다. 본 연구는 신용평가사가 생성한 신용지표들의 신뢰성을 보다 확실하게 검증하기 위하여 감리지적과의 관련성을 살펴보았다. 감리지적은 기업의 회계정보에 대한 회계감사 이후 사후적으로 제공된 회계정보의 적절성과 회계감사의 적합성을 검증하는 제도이다. 만약 사후적인 감리조사로 인하여 감리지적사유가 발견된다면 해당 회계정보의 신뢰성이 의심받게 될 것이다. 따라서 신용평가사는 감리지적 사유가 발생한 해당연도 혹은 감리지적 사유가 발표되기 이전에 신용평가를 실시함에 있어서 감리지적 사유와 관련된 사항을 신용등급에 반영을 하여 신용등급 정보에 감리지적 사유에 해당하는 정보가 포함되도록 평가하여야지만 신용평가 정보의 신뢰성이 확보될 것이고, 신용정보 이용자에게 유용한 정보가 될 것이다. 이러한 검증을 위하여 본 연구는 코스피 및 코스닥 등록기업의 1998년부터 2007년까지 금융감독원과 한국공인회계사회에 의한 감리지적기업과 감리비지적기업을 대상으로 감리지적정보와 신용지표간에 관련성을 검증함으로써 신용평가사들이 제공하고 있는 신용지표들의 신뢰성을 확인함을 목적으로 한다. 이를 위한 신용지표는 신용평가 3사(한국기업평가, 한국신용정보, 한국신용평가)가 제공하는 신용등급과 한국신용평가에서 제공하는 신용평점과 재무평점을 사용하였고, 감리관련 자료는 금융감독원과 한국공인회계사회에서 실시한 감리지적 유·무 및 감리지적 사유를 사용하였다. 분석결과 신용평가사의 신용지표들과 감리지적간에는 유의적인 음(-)의 관련성이 확인되어, 김리지적을 받은 기업의 신용지표들은 낮게 평가되었다. 이러한 결과는 신용평가사들이 신용지표를 도출함에 있어서 단지 재무제표에 나타나 있는 회계정보만을 활용하는 것이 아니라, 감리지적으로 밝혀질 만한 중요한 사항에 대해서도 정밀하게 측정하여 신용지표를 도출하고 있는 것으로 판단 할 수 있을 것이다. 이로써 신용평가사들이 기계적인 재무분석에서는 알 수 없는 정보를 신용등급에 반영함으로써 신뢰성과 정확성을 높이며, 신용평가기관으로서 그 역할을 충실히 수행하고 있는 것으로 판단된다. 본 연구의 의의는 그동안 연구가 많지 않았던 신용등급과 감리지적정보의 관계를 분석하여 신용평가사의 신용지표의 신뢰성과 정확성을 감리지적이라는 명확한 정보를 활용하여 신용평가사의 기능을 재검증하였다는데 의의가 있다. Credit rating agency (CRA) provides the Credit Index, which is used in a wild range of areas such as corporate evaluation, risk management, loan business, capital finance and investment. Accordingly, the reliability of Credit Index has a great influence on the reliability of tasks which make use of it. This is why the reliability of Credit Index itself is important. Therefore, confirming the reliability of Credit Index and improving its functions will be the foundation of revitalizing the capital market. Enforcement action is the system for evaluating the propriety of accounting information and the suitability of audited financial statement by finding misinformation and material misstatement. Thus, before conducting credit evaluation of the year when the enforcement action occurred or when the cause was announced, CRAs should allow those enforcement actions or the causes to be included in the credit rating information in order to secure the reliability of credit evaluation information, which would be helpful to the user as well. The purpose of this study is to examine the reliability of CRAs' credit index by verifying the relationship between enforcement action and Credit Index. We identify two groups of listed firms on the KOSPI and KOSDAK, whether the firms is subjected to enforcement action or not from 1998 to 2007. We used the credit index provided by big three CRAS as well as the credit and finance marks presented by the Korean Investors Service Inc.. The enforcement materials used are the enforcement action status and the causes, pointed out by the Financial Supervisory and the Korean Institute of Certified Public Accountants. We find that there was a negative relationship between CRAs' credit index and enforcement action. It means corporations under enforcement action are evaluated lower credit index than the corporations, which are not under enforcement action. This result shows that CRAs use not only the accounting information in the financial statements, but other important information, revealed by enforcement action to calculate Credit Index. By reflecting both information to calculate credit index, CRSs increase the reliability of credit index.

Wind Pressure Statistics and Target Reliability Index for Wind Load-governed Limit State of Reliability-based Bridge Design Codes

이해성,김지현 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.5

This paper presents a general procedure for evaluating a proper target reliability index and corresponding wind load factor for a wind load-governed limit state in reliability-based design codes. The Monte-Carlo simulation is conducted to reveal relationships between statistical parameters of wind velocity and pressure. The normalized wind pressure is defined and used in the simulations. The analytical form of the wind load factor is presented in terms of the statistical parameters of wind velocity and the target reliability index. The return period of a nominal wind velocity is expressed for the target reliability index and the wind load factor. An approach determining the target reliability index based on the return period of wind velocity at the limit state is proposed. The return period of wind velocity at the limit state is set to that of the design earthquake in a design code. The proposed approach is applied to calculate the target reliability index for the Korean Highway Bridge Design Code-Cable supported Bridge. The target reliability index is found as 2.25, and the corresponding wind load factor ranges from 1.60 to 1.82 depending on the Coefficient of Variation (COV) of wind velocity. Detailed discussions on the return period of wind velocity, target reliability index and wind load factor are made. A simplified expression of the wind load factor corresponding to the target reliability of 2.25 is proposed. The basic wind velocities for five regions in the Korean Highway Bridge Design Code (Limit State Design) are estimated through the proposed procedure.

Fuzzy 집합 이론을 이용한 홍수조절효과 정량화 지표 개발

김주욱(Kim,Juuk),최창원(Choi,Changwon),이재응(Yi,Jaeeung) 대한토목학회 2011 대한토목학회논문집 B Vol.31 No.5B

현재 국내에서 주로 시용되고 있는 홍수기 다목적댐의 홍수조절효과에 대한 정량적인 평가지표로는 유량조절률, 저수지 방류율, 저수지 저류율, 저수지 이용률 등이 있다. 이러한 평가지표들은 유입량, 방류량, 저류량 등의 자료를 단순 비교하는 방법을 사용하고 있는데, 홍수조절효과 평가지표 산정식에 사용되는 자료들이 가지는 불확실성이 평가에 고려되지 못하고 있으며, 저수지에서 얻을 수 있는 자료만을 사용하기 때문에 저수지 하류 지점에서의 홍수조절효과를 적절히 평가하지 못하고 있다. 또한 이러한 지표들은 수자원 시스템의 설계에 있어서 허용 가능한 부분적인 실패를 고려하지 못하는 등의 문제점이 존재하므로, 홍수조절효과를 정량화 할 수 있는 새로운 지표의 개발이 요구된다. 본 연구에서는 각종 변수들이 가지는 불확실성, 댐 하류지점에서의 홍수조절효과, 수자원 시스템에서 허용 가능한 부분적 실패를 고려하기 위하여 홍수조절효과 정량화 지표 개발에 fuzzy 집합이론을 적용하였다. 본 연구를 통해 개발한 홍수조절효과 정량화 지표를 이용하여 다목적댐의 홍수조절효과를 평가하였다. 연구 대상 유역으로는 충주댐 유역을 선정하였고, 대상 홍수 사상으로는 2006년 7월의 홍수시상을 적용하였다. 개발한 홍수조절효과 정량화 지표를 이용하여 홍수조절효과를 평가하기 위해 관련 인자들을 퍼지화하고 시스템의 상태로부터 허용 기능한 부분적인 실패 영역을 구분하여 홍수조절효과 정랑화 지표를 산정하였다. 적용결과, 본 연구를 통하여 개발된 통합 신뢰도-취약도 지수는 저수지의 홍수조절효과를 기존의 지표보다 구체적이고 객관화하여 나타낼 수 있었다. Quantitative evaluation indexes for flood control effect of a multi-purpose reservoir used widely in Korea are the discharge control rate, reservoir release rate, reservoir storage rate, and flood control storage utilization rate. Because these indexes usually use and compare inflow, release, and storage data directly, the uncertainties included in these data are not considered in evaluation process, and the downstream flood control effects are not assessed properly. Also, since the acceptable partial failure in a design of water resources system is not considered, the development of a new flood control effect evaluation index is required. Fuzzy set theory is therefore applied to the development of the index in order to consider the data uncertainty, the downstream flood control effect, and the acceptable partial failure. In this study, the flood control effect of a multi-purpose reservoir is evaluated using the flood control effect index developed by applying fuzzy set theory. The Chungju reservoir basin was selected as a study basin and the storm events of July, 2006 are used to study the applicability of the developed index. The related factors for flood control effect are fuzzified, the acceptable failure region is divided from the system state to evaluate the flood control effect using developed flood control effect index. The flood control effect index were calculated by applying to the study basin and storm events. The results show that the developed index can represent the flood control effect of a reservoir more realistically and objectively than the existing index.Quantitative evaluation indexes for flood control effect of a multi-purpose reservoir used widely in Korea are the discharge control rate, reservoir release rate, reservoir storage rate, and flood control storage utilization rate. Because these indexes usually use and compare inflow, release, and storage data directly, the uncertainties included in these data are not considered in evaluation process, and the downstream flood control effects are not assessed properly. Also, since the acceptable partial failure in a design of water resources system is not considered, the development of a new flood control effect evaluation index is required. Fuzzy set theory is therefore applied to the development of the index in order to consider the data uncertainty, the downstream flood control effect, and the acceptable partial failure. In this study, the flood control effect of a multi-purpose reservoir is evaluated using the flood control effect index developed by applying fuzzy set theory. The Chungju reservoir basin was selected as a study basin and the storm events of July, 2006 are used to study the applicability of the developed index. The related factors for flood control effect are fuzzified, the acceptable failure region is divided from the system state to evaluate the flood control effect using developed flood control effect index. The flood control effect index were calculated by applying to the study basin and storm events. The results show that the developed index can represent the flood control effect of a reservoir more realistically and objectively than the existing index.

한방의료 품질 향상을 위한 신뢰구현 체계구축 연구

김현지,김소연,지영승,김정호,남승규,김영일 대한침구의학회 2014 대한침구의학회지 Vol.31 No.1

Objectives : This study was designed to establish medical trust realization system by finding factors influential to it using questionnaire. Methods : 277 subjects were participated in this study. After a treatment, we conducted a survey from April 1st to October 31th about medical service perception index, medical trust index, patient satisfaction index, patient reliability index, patient flow degree index, recall intension index, and hospital image index. To evaluate the influence of medical service perception with other 6 indexes, we statistically made regression analysis of the results through the survey. Results : By the results of the analysis, evaluation of hospital image influenced all 6 indexes. The systemicity of treatment process had an effect on 5 indexes except for the flow degree of patients. The humanity of medical team brought out the estimation of 4 indexes except for the patient flow degree and hospital image. The empathic ability of doctor and appropriacy of medical costs hold the next rank influencing 3 indexes. It reached the conclusion that the systemicity of medical team tend to determine the medical trust and patient reliability. The expertise, professional skill of doctor, the fault, commercial application, fame of medical team, the speed of treatment process, the newest and clean medical facility affected each one index. Conclusions : Korean medicine should find a way to consider the mind of patients for improving the medical quality through trust realization system, keeping up with times. As a result of this research, we can find out important causes which influence the trustful medical system. From now on, we should apply this result to actual treatment of psychology customized system. Also, more simple and clear questionnaire was organized through this research, it can be used to forward research to apprehend patient mentality more conveniently.

Reliability assessment of reinforced concrete rectangular columns subjected to biaxial bending using the load contour method

Kim, Ji Hyeon,Lee, Hae Sung Elsevier 2017 Engineering structures Vol.150 No.-

<P><B>Abstract</B></P> <P>This paper presents the reliability assessment of reinforced concrete (RC) columns subjected to biaxial bending using the advanced first-order second-moment reliability method. The strength of an RC column under the biaxial bending condition is estimated by the load contour, which is utilized as the limit state function in the reliability analysis. The random variables include the strength parameters of the RC columns, the load parameters and the eccentricities of axial force. The Hasofer-Lind-Rackwitz-Fiessler algorithm with the gradient projection method is employed to calculate the most probable failure point and the reliability index. The surface exponents of the load contours are determined by the values presented by Bresler. The cubic spline interpolation is adopted to construct P-M interaction diagrams for uniaxial bending about the principal axes that are required in the load contour method. The sensitivities of the limit state function are calculated through the direct differentiation method. The reliability indices are calculated for a rectangular section and a square section. The effect of the surface exponent on the results of the reliability analysis is investigated for the rectangular section, and the uncertainty of the eccentricity of axial force is considered in the example for the square section.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Reliability assessment of RC columns subjected to biaxial bending using the AFOSM. </LI> <LI> Evaluation of column strength based the load contour method. </LI> <LI> Cubic spline interpolation for the PMID for uniaxial bending. </LI> <LI> Derivation of the explicit expressions for sensitivities of the failure surface. </LI> <LI> Consideration of uncertainties of external loads as well as load eccentricities. </LI> </UL> </P>

Reliability-Based Topology Optimization Based on Bidirectional Evolutionary Structural Optimization

유진식,김상락,박재용,한석영 한국생산제조학회 2010 한국생산제조학회지 Vol.19 No.4

This paper presents a reliability-based topology optimization (RBTO) based on bidirectional evolutionary structural optimization (BESO). In design of a structure, uncertain conditions such as material property, operational load and dimensional variation should be considered. Deterministic topology optimization (DTO) is performed without considering the uncertainties related to the design variables. However, the RBTO can consider the uncertainty variables because it can deal with the probabilistic constraints. The reliability index approach (RIA) and the performance measure approach (PMA) are adopted to evaluate the probabilistic constraints in this study. In order to apply the BESO to the RBTO, sensitivity number for each element is defined as the change in the reliability index of the structure due to removal of each element. Smoothing scheme is also used to eliminate checkerboard patterns in topology optimization. The limit state indicates the margin of safety between the resistance (constraints) and the load of structures. The limit State function expresses to evaluate reliability index from finite element analysis. Numerical examples are presented to compare each optimal topology obtained from RBTO and DTO each other. It is verified that the RBTO based on BESO can be effectively performed from the results.

성인 편마비 환자의 균형 및 운동 기능평가를 위한 신뢰도 연구

정지운(Jung Jee-Woon),김희수(Kim Hee-Soo) 대한치료과학회 2016 대한치료과학회지 Vol.8 No.1

Objective: The aim of this study was to examine inter-rater reliability of the TIS(Trunk Impairment Scale), K-BBS (K-Berg Balance Scale) and RMI (Rivermead Mobility Index) based on video clips. In additions, the test-retest reliability of the K-BBS, TIS and RMI was evaluated according to the 1st test and 2nd test. Method: We evaluated the 33 hemiplegic patients video (male 22, female 11, range of age 53.45±2.45) with stroke for intra-rater reliability. Six experienced physical therapists and one medical doctor attended education sessions about the scoring system. They scored simultaneously by watching the video clips that recorded another therapist’s examination with patients. To examine the test-retest reliability, it was measured twice on 14 separate days. Intraclass correlation coefficients (ICC)s were analyzed to determine the intra-rater and test-retest reliability. Results: Test-retest reliability values of TIS was .908 were also high, intraclass correlation coefficient (ICC3,1) varying from .979-.993. Intra-rater reliability values of the TIS, K-BBS and RMI were mostly high, varying from .931-.993, .976-.996, 1.000-1.000. Conclusion: The TIS, BBS and RMI were shown to be reliable tools to measure quantity and quality of functional status for hemiplegic patients. Video scoring was time-consuming, but was found to offer many advantages; the possibility to review performance, to use special trained raters for scoring and less demanding assessment for the patients. In addition, research on the reliability and validity of the assessment tool for objective assessment and treatment of patients should be continued in the future.

Reliability-Based Topology Optimization Based on Bidirectional Evolutionary Structural Optimization

Jin-Shik Yu(유진식),Sang-Rak Kim(김상락),Jae-Yong Park(박재용),Seog-Young Han(한석영) 한국생산제조학회 2010 한국생산제조학회지 Vol.19 No.4

This paper presents a reliability-based topology optimization (RBTO) based on bidirectional evolutionary structural optimization (BESO). In design of a structure, uncertain conditions such as material property, operational load and dimensional variation should be considered. Deterministic topology optimization (DTO) is performed without considering the uncertainties related to the design variables. However, the RBTO can consider the uncertainty variables because it can deal with the probabilistic constraints. The reliability index approach (RIA) and the performance measure approach (PMA) are adopted to evaluate the probabilistic constraints in this study. In order to apply the BESO to the RBTO, sensitivity number for each element is defined as the change in the reliability index of the structure due to removal of each element. Smoothing scheme is also used to eliminate checkerboard patterns in topology optimization. The limit state indicates the margin of safety between the resistance (constraints) and the load of structures. The limit State function expresses to evaluate reliability index from finite element analysis. Numerical examples are presented to compare each optimal topology obtained from RBTO and DTO each other. It is verified that the RBTO based on BESO can be effectively performed from the results.

Mechanical reliability analysis of tubes intended for hydrocarbons

Mourad Nahal,Rabia Khelif 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.2

Reliability analysis constitutes an essential phase in any study concerning reliability. Many industrialists evaluate and improve the reliability of their products during the development cycle—from design to startup (design, manufacture, and exploitation)—to develop their knowledge on cost/reliability ratio and to control sources of failure. In this study, we obtain results for hardness, tensile, and hydrostatic tests carried out on steel tubes for transporting hydrocarbons followed by statistical analysis. Results obtained allow us to conduct a reliability study based on resistance request. Thus, index of reliability is calculated and the importance of the variables related to the tube is presented. Reliability-based assessment of residual stress effects is applied to underground pipelines under a roadway, with and without active corrosion. Residual stress has been found to greatly increase probability of failure, especially in the early stages of pipe lifetime.