• 제목/요약/키워드: Reliability measure

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두통 평가 척도에 관한 고찰 - 신뢰도와 타당도를 중심으로 - (Review Study of Headache Measurement Tools - Mainly on Reliability and Validity -)

  • 김은정;정찬영;장민기;윤은혜;남동우;강중원;이재동;이승덕;김갑성
    • Journal of Acupuncture Research
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    • 제27권1호
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    • pp.51-64
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    • 2010
  • Objectives : To introduce and compare various headache measurement tools, in order to provide fundamental information for future clinical trials and development of oriental medicine measurement tools. Methods : Eight headache assessment scales, Migraine-Specific Quality of Life Questionnaire(MQoLQ), Migraine-Specific Quality of Life(MSQOL), Migraine-Specific Quality of Life Questionnaire(MSQ), The Headache Impact Questionnaire(HImQ), Headcahe Needs Assessment Survey(HANA), Henry Ford Headache disability Inventory(HDI), Migraine Disablity Assessment Scale(MIDAS) and Headache Impact Test(HIT-6), were searched through Pubmed. General character, the process of development, verification of reliability, internal consistency, responsiveness to patient's change and validity were reviewed. Results : In assessing the quality of life of migraine patients, MQoLQ can be used to measure the change within 24 hours, MSQ and MSQOL can be used to measure the change during a relatively longer period of time. The frequency and bothersomeness of headache can be easily measured by HANA. HImQ can be used to measure the intensity of headache and the influence on normal daily activities. HDI can measure the emotional difficulties of headache patients. HIT-6 and MIDAS makes measurements possible in a short period of time, and the reliability and validity have been verified numerously. HIT-6 and MIDAS are the most frequently used measurement tools because they are simple and easy for both the assessor and the patient to understand and use. Conclusions : In this study, various headache assessment tools have been reviewed. The assessed tools were widely used after being verified for their reliability and validity. We hope this study provides fundamental information in establishing future clinical trial and clinical practice guidelines. We also hope this study to contribute to the development of an oriental medicine assessment tool for headache.

Reliability of Lateral Deviation Measurement in the Hyoid Bone With Center Point and Lateral Motion Tests

  • Min, Hye-jin;Yoon, Tae-lim
    • 한국전문물리치료학회지
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    • 제26권3호
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    • pp.76-83
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    • 2019
  • Background: The hyoid bone is the only non-jointed structure among the skeletal tissues of the head and neck region, and its movement and posture depend on the attached muscle, ligament, and fascia. The location of the hyoid bone is important for airway maintenance, vocalization, chewing, swallowing, breathing, and head and scapular position. In general, the location of the hyoid bone is measured using radiographs and 3D computed tomography, and no studies have reported on clinical measurement methods. Objects: This study was performed to suggest clinical measurement methods for lateral deviation of the hyoid bone and to evaluate their reliability. Methods: In this study, 24 healthy volunteers (12 males, 12 females) in Cheongju-si participated. Two examiners performed the center point test and lateral motion test twice each to measure the lateral displacement of the hyoid bone. The reliability of the center point test was analyzed using intra-class correlation coefficients (ICC), and the reliability of the lateral motion test was analyzed using Cohen's kappa coefficient. Results: The intra-rater reliability of the center point test was good, and the inter-rater reliability was moderate. The intra- and inter-rater reliability of the lateral motion test showed substantial reliability. Conclusion: Based on these results, the center point test and the lateral motion test can be used as an alternative methods of the measurement of lateral deviation of the hyoid bone for people who have musculoskeletal disorders of the head, neck, and scapula.

Variation of reliability-based seismic analysis of an electrical cabinet in different NPP location for Korean Peninsula

  • Nahar, Tahmina Tasnim;Rahman, Md Motiur;Kim, Dookie
    • Nuclear Engineering and Technology
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    • 제54권3호
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    • pp.926-939
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    • 2022
  • The area of this study will cover the location-wise seismic response variation of an electrical cabinet in nuclear power point (NPP) based on classical reliability analysis. The location-based seismic ground motion (GM) selection is carried out with the help of probabilistic seismic hazard analysis using PSHRisktool, where the variation of reliability analysis can be understood from the relation between the reliability index and intensity measure. Two different approaches such as the first-order second moment method (FOSM) and Monte Carlo Simulation (MCS) are helped to evaluate and compare the reliability assessment of the cabinet. The cabinet is modeled with material uncertainty utilizing Steel01 as the material model and the fiber section modeling approach is considered to characterize the section's nonlinear reaction behavior. To verify the modal frequency, this study compares the FEM result with recorded data using Least-Squares Complex Exponential (LSCE) method from the impact hammer test. In spite of a few investigations, the main novelty of this study is to introduce the reader to check and compare the seismic reliability assessment variation in different seismic locations and for different earthquake levels. Alongside, the betterment can be found by comparing the result between two considered reliability estimation methods.

Effect of Constitutive Material Models on Seismic Response of Two-Story Reinforced Concrete Frame

  • Alam, Md. Iftekharul;Kim, Doo-Kie
    • International Journal of Concrete Structures and Materials
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    • 제6권2호
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    • pp.101-110
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    • 2012
  • This paper focuses on the finite element (FE) response sensitivity and reliability analyses considering smooth constitutive material models. A reinforced concrete frame is modeled for FE sensitivity analysis followed by direct differentiation method under both static and dynamic load cases. Later, the reliability analysis is performed to predict the seismic behavior of the frame. Displacement sensitivity discontinuities are observed along the pseudo-time axis using non-smooth concrete and reinforcing steel model under quasi-static loading. However, the smooth materials show continuity in response sensitivity at elastic to plastic transition points. The normalized sensitivity results are also used to measure the relative importance of the material parameters on the structural responses. In FE reliability analysis, the influence of smoothness behavior of reinforcing steel is carefully noticed. More efficient and reasonable reliability estimation can be achieved by using smooth material model compare with bilinear material constitutive model.

블록체인 환경에서 Email 사용자 신뢰도 측정 (Measuring Email User Reliability in a Blockchain Environment)

  • 김대한;서경룡
    • 한국멀티미디어학회논문지
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    • 제23권8호
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    • pp.1030-1039
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    • 2020
  • The biggest feature of the online environment is anonymity. So it is difficult to identify the sender accurately in Email. So we use PGP to enhance the security of email. PGP is an e-mail encryption program that has become the standard for email security worldwide. But PGP has a weak point in security. PGP can identify users, but it is difficult to verify reliability. In PGP, the more reliable other users guarantee that user are, the more reliable they are. In the previous study, the PGP structure was implemented by utilizing the block chain to lay the foundation, and in this paper, the structure of the previous article is applied to the e-mail environment to measure up the sender's reliability, and a system is proposed that allows users to distinguish the reliability of the message.

신뢰성 이론을 이용한 공급 사슬 시스템의 평가 척도에 관한 연구 (A Performance Measure for Supply Chain System using Reliability Theory)

  • 조민관;이영해
    • 한국산업경영시스템학회:학술대회논문집
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    • 한국산업경영시스템학회 2002년도 춘계학술대회
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    • pp.195-202
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    • 2002
  • The primary objective of Supply Chain Management (SCM) is to optimize the cash, material and information flow for satisfying customer demands through coordinating the relationship between Supply Chain components such as suppliers, manufacturers, and inventories, etc. By Supply Chain Planning (SCP), operation tasks or goals, should be done in specific due date, are ordered to each SC component for achieving such objective. However, the achievement for operation tasks or goals is affected by uncertainties in SC. In general, reliability theory Is explained as the probability that a product or system will perform its specified function under prescribed conditions without failure for a specified period of time. Therefore, the reliability of SC can be defined as the probability that SC will satisfy customer demands until the specific due date. In this paper, a basic framework to evaluate reliability is respectively proposed as supply chain components, and then a overall framework to estimate the reliability for SC is also proposed.

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장애 함수를 이용한 신뢰성 기반 최적 설계 (Reliability Based Design Optimization Using Barrier Function)

  • 이태희;최운용;이광기
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2002년도 정기학술대회
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    • pp.211-216
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    • 2002
  • 실제적인 문제에서 신뢰성 기반 최적 설계(RBDO)를 구현하기 위해서는 유한요소 모델을 해석하기 위한 상용 프로그램과 설계한 것에 대한 신뢰성을 산정할 수 있는 프로그램을 통합하고 최적화 알고리듬을 적용하여야 최적화를 수행하여야만 한다. 또한 최적화 과정에서 최적상태에서 제약조건이 비활성 영역에서 놓이게 되는 것을 방지하기 위해서 제약조건 최적화 문제를 비제약 조건 최적화 문제로 바꾸어 주는 장애 함수를 사용하여 최적화를 수행하였다. 그리고 이 방법론을 기존의 신뢰성기반 최적화 방법론, 즉 신뢰도지수 접근방법과 목표성능치 접근방법과의 비교를 하였다.

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컴플라이언트 메커니즘의 신뢰성 기반 위상최적설계 (Reliability Based Topology Optimization of Compliant Mechanisms)

  • 임민규;박재용;한석영
    • 한국생산제조학회지
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    • 제19권6호
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    • pp.826-833
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    • 2010
  • Electric-thermal-structural actuated compliant mechanisms are mechanisms onto which electric voltage drop is applied as input instead of force. This mechanism is based on thermal expansion of material while being heated. Compliant mechanisms are designed subjected to electric charge input using BESO(bi-directional evolutionary structural optimization) method. Reliability-based topology optimization (RBTO) is applied to the topology design of actuators. performance measure approach (PMA), which has probabilistic constraints that are formulated in terms of the reliability index, is adopted to evaluate the probabilistic constraints. In this study, BESO method is used to obtain optimal topology of compliant mechanisms from initial design domain. PMA approach is used to evaluate reliability index. The procedure has been tested in numerical applications and compared with the results obtained by other methods to validate these approaches.

Reliability Evaluation for Hinge of Folder Devices Using ESPI

  • Kyungyoung Jhang;Minkwan Hyun;Lee, Taehun;Seokwon Chang
    • International Journal of Reliability and Applications
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    • 제5권1호
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    • pp.15-24
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    • 2004
  • Folder type electronic devices have hinge to support the rotational motion of folder. This hinge is stressed by the rotational inertia moment of folder at the maximum open limit position of folder. This stress is repeated whenever the folder is open, and it is a cause of hinge fracture. In this paper, the reliability evaluation for the hinge fracture in the folder type cellular phone is discussed. For this, the durability testing machine using crank-rocker mechanism is developed to evaluate the life cycle of the hinge, and the degradation after repetitions of opening and shutting is evaluated from the deformation around the hinge, where the deformation is measured by ESPI (electronic speckle pattern interferometer). Experimental results showed that ESPI was able to measure the deformation of hinge precisely, so we could monitor the change of deformation around the hinge as the repetition number of folder open is increased.

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배관감육 평가를 위한 UT 측정 신뢰도 분석 (Reliability Analysis of UT Measurement for Evaluating Pipe Wall Thinning in Nuclear Power Plants)

  • 윤훈;황경모
    • Corrosion Science and Technology
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    • 제11권4호
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    • pp.129-134
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    • 2012
  • UT(Ultrasonic Test), one of the non-destructive tests, is the most common thickness measurement method for evaluating the wear rate in NPPs(Nuclear Power Plants). UT is used widely because it is easy and safe for use. However some amount of error inevitably occurs in attempting to measure the thickness. The error, that could make the thickness data thicker or thinner, may affect estimation of wear rate in pipes. NPPs are composed of a lot of pipes and components. Some of them are tested to check the current status during RFO(Re-Fueling Outage). Reliability analysis of UT is essential for evaluating pipe wear rate and establishing the long-term management plan in NPPs. This paper reviewed the cause of error occurrence and presented the UT data reliability analysis method. Also, this paper shows the application result of reliability analysis to the UT data acquired in NPPs.