• Title/Summary/Keyword: component failure

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An Empirical Study on the Obligations of Contractual Parties for Successful IT Outsourcing (성공적인 IT 아웃소싱을 위한 계약당사자간 책임 요소에 대한 실증 연구)

  • Kim, Young-Gon
    • Journal of the Korean Society for information Management
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    • v.24 no.3
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    • pp.21-41
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    • 2007
  • IT outsourcing has become a critical component of organizations, but improper expectations, ambiguous contracts and unclear goals frequently cause the failure of IT outsourcing. Especially we have to be concerned about the uncareful management of customer-supplier relationships based on a psychological contract perspective. This study focuses on the obligations of contractual parties for IT outsourcing which influence the outsourcing relationship(OR) and the successful performance of IT outsourcing(OP). The supplier obligations consist of the achievable infrastructure(S1) and capability(S2), and the customer obligations is composed of the acceptable environment(C1) and acceptability(C2) for IT outsourcing. This paper shows that the S1, S2, and C2 have an effect on the OR, the OR on the OP, and the S2 also on the OP directly. The four components of customer-supplier obligations are mutually related to each other. What is more, we must notice that the S2 has strong connections with the C2.

Comparison of numerical and analytical solutions for reinforced soil wall shaking table tests

  • Zarnani, Saman;El-Emam, Magdi M.;Bathurst, Richard J.
    • Geomechanics and Engineering
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    • v.3 no.4
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    • pp.291-321
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    • 2011
  • The paper describes a simple numerical FLAC model that was developed to simulate the dynamic response of two instrumented reduced-scale model reinforced soil walls constructed on a 1-g shaking table. The models were 1 m high by 1.4 m wide by 2.4 m long and were constructed with a uniform size sand backfill, a polymeric geogrid reinforcement material with appropriately scaled stiffness, and a structural full-height rigid panel facing. The wall toe was constructed to simulate a perfectly hinged toe (i.e. toe allowed to rotate only) in one model and an idealized sliding toe (i.e. toe allowed to rotate and slide horizontally) in the other. Physical and numerical models were subjected to the same stepped amplitude sinusoidal base acceleration record. The material properties of the component materials (e.g. backfill and reinforcement) were determined from independent laboratory testing (reinforcement) and by back-fitting results of a numerical FLAC model for direct shear box testing to the corresponding physical test results. A simple elastic-plastic model with Mohr-Coulomb failure criterion for the sand was judged to give satisfactory agreement with measured wall results. The numerical results are also compared to closed-form solutions for reinforcement loads. In most cases predicted and closed-form solutions fall within the accuracy of measured loads based on ${\pm}1$ standard deviation applied to physical measurements. The paper summarizes important lessons learned and implications to the seismic design and performance of geosynthetic reinforced soil walls.

Chronic postsurgical pain: current evidence for prevention and management

  • Thapa, Parineeta;Euasobhon, Pramote
    • The Korean Journal of Pain
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    • v.31 no.3
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    • pp.155-173
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    • 2018
  • Chronic postsurgical pain (CPSP) is an unwanted adverse event in any operation. It leads to functional limitations and psychological trauma for patients, and leaves the operative team with feelings of failure and humiliation. Therefore, it is crucial that preventive strategies for CPSP are considered in high-risk operations. Various techniques have been implemented to reduce the risk with variable success. Identifying the risk factors for each patient and applying a timely preventive strategy may help patients avoid the distress of chronic pain. The preventive strategies include modification of the surgical technique, good pain control throughout the perioperative period, and preoperative psychological intervention focusing on the psychosocial and cognitive risk factors. Appropriate management of CPSP patients is also necessary to reduce their suffering. CPSP usually has a neuropathic pain component; therefore, the current recommendations are based on data on chronic neuropathic pain. Hence, voltage-dependent calcium channel antagonists, antidepressants, topical lidocaine and topical capsaicin are the main pharmacological treatments. Paracetamol, NSAIDs and weak opioids can be used according to symptom severity, but strong opioids should be used with great caution and are not recommended. Other drugs that may be helpful are ketamine, clonidine, and intravenous lidocaine infusion. For patients with failed pharmacological treatment, consideration should be given to pain interventions; examples include transcutaneous electrical nerve stimulation, botulinum toxin injections, pulsed radiofrequency, nerve blocks, nerve ablation, neuromodulation and surgical management. Physical therapy, cognitive behavioral therapy and lifestyle modifications are also useful for relieving the pain and distress experienced by CPSP patients.

Experimental study on standard and innovative bolted end-plate beam-to-beam joints under bending

  • Katula, Levente;Dunai, Laszlo
    • Steel and Composite Structures
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    • v.18 no.6
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    • pp.1423-1450
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    • 2015
  • The paper presents the details and results of an experimental study on bolted end-plate joints of industrial type steel building frames. The investigated joints are commonly used in Lindab-Astron industrial buildings and are optimized for manufacturing, erection and durability. The aim of the research was to provide an experimental background for the design model development by studying load-bearing capacity of joints, bolt force distribution, and end-plate deformations. Because of the special joint details, (i.e., joints with four bolts in one bolt-row and HammerHead arrangements), the Eurocode 3 standardized component model had to be improved and extended. The experimental programme included six different end-plate and bolt arrangements and covered sixteen specimens. The steel grade of test specimens was S355, the bolt diameter M20, whereas the bolt grade was 8.8 and 10.9 for the two series. The end-plate thickness varied between 12 mm and 24 mm. The specimens were investigated under pure bending conditions using a four-point-bending test arrangement. In all tests the typical displacements and the bolt force distribution were measured. The end-plate plastic deformations were measured after the tests by an automatic measuring device. The measured data were presented and evaluated by the moment-bolt-row force and moment-distance from centre of compression diagrams and by the deformed end-plate surfaces. From the results the typical failure modes and the joint behaviour were specified and presented. Furthermore the influence of the end-plate thickness and the pretension of the bolts on the behaviour of bolted joints were analysed.

Experimental study on seismic performance of reinforced concrete frames retrofitted with eccentric buckling-restrained braces (BRBs)

  • Yang, Yong;Liu, Ruyue;Xue, Yicong;Li, Hui
    • Earthquakes and Structures
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    • v.12 no.1
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    • pp.79-89
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    • 2017
  • As a new type of energy dissipation component with excellent mechanical performance, the Buckling-Retrained Braces (BRBs) were gradually applied in retrofitting and improving seismic performance of reinforced concrete structures in China. In order to investigate the seismic performance of reinforced concrete structures retrofitted with BRBs, quasi-static test of two single-bay and 3-story reinforced concrete frames specimens was conducted and introduced in this paper. Two 1/2 scaled specimens were designed to reflect real prototype structure. For comparison, one control specimen was designed without BRBs, and the other specimen was retrofitted with BRBs. And particularly, for the specimen retrofitted with BRBs, the BRBs were eccentric layout instead of usually concentric or x-shaped layout, aiming to be more suitable for large-span frames. In the test, the failure mode, carrying capacity, deformability, ductility and energy dissipation ability of both two specimens were investigated. Based on the test results of the measured hysterical curves, skeleton curves, the seismic performances such as bearing capacity, plastic deformability, energy dissipation ability and ductility of two specimens were fully studied. And from the test results, it was indicated that the specimen retrofitted with BRBs showed much better seismic performance than the control specimen without BRBs, and the BRBs could effectively improve the seismic performance of the reinforced concrete frame. For the specimen retrofitted with BRBs, the BRBs firstly yielded before the beam-ends and the column-ends, and an expected yielding process or yielding mechanism as well as good seismic performance was obtained. For the specimens without BRBs, though the beam-ends yielded prior to the column-ends, the seismic performance was much poor than that of the specimen with BRBs.

Failure Load Prediction of Tunnel Support using DOE and Optimization Algorithm (실험계획법과 최적화알고리듬을 이용한 터널지보의 파손하중 예측)

  • Lee, Dong-Woo;Cho, Seok-Swoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.4
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    • pp.1480-1487
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    • 2012
  • Recently, the safety of the coal-mining tunnels has been improved greatly, but accidents occur continually. Most tunnel support failures occur because the fish plate part that connects the I-beams is unable to withstand ground pressure. In the case of XX coal mine, the arch part of tunnel support bends to the upper direction. In such a case, excessive horizontal load as well as vertical load acts on the tunnel support. Horizontal load is caused by the sudden loosing of underground rock mass or the leakage of underground water, so it is fairly complex to predict horizontal loading on a tunnel support. To predict the horizontal load on this component is defined as the problem that determines the horizontal load conditions in wedges of tunnel support. This is an optimization problem in which maximum bending stress and horizontal load are considered by an objective function and design variables, respectively. Therefore, in this study, design of experiments and optimization algorithm were applied to identify the horizontal load in tunnel support.

Prioritize Front-Loading Factors Analysis for New Product Development : Focus on Automobile Parts Design Stage (신제품개발을 위한 프론트로딩 요소 우선순위 도출 : 자동차부품 설계단계 중심으로)

  • Park, Byung-Hag;Ock, Young-Seok;Chun, Dong-Phil;Park, Se-hun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.42 no.4
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    • pp.31-38
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    • 2019
  • The purpose of this study is to provide the priority of the front-loading factors in the design stage of the automotive parts development process in order to efficiently and effectively respond to the demands of the car maker (customer). Front-loading is defined as a strategy in order to improve development performance by shifting the identification and solving of design problems to earlier phases of a product development process. Two approaches of the front-loading are project-to-project knowledge transfer and rapid problem solving. For the study, a survey was conducted on the R&D department in the automobile parts company and analyzed by AHP (Analytic Hierarchy Process) method. The result of the survey shows the cost savings is the highest weight in terms of front-loading effect and in terms of front-loading factors, it gives priorities as "the problems of past project" first, "Design Review" second, "CAE (Computer Aided Engineering)" third, "FMEA (Failure Mode and Effects Analysis)" fourth, "benchmarking" and SR (Sourcing of Requirements). The results of the study will be helpful to provide practical value for improving product design of component development.

Skew correction of face image using eye components extraction (눈 영역 추출에 의한 얼굴 기울기 교정)

  • Yoon, Ho-Sub;Wang, Min;Min, Byung-Woo
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.12
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    • pp.71-83
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    • 1996
  • This paper describes facial component detection and skew correction algorithm for face recognition. We use a priori knowledge and models about isolated regions to detect eye location from the face image captured in natural office environments. The relations between human face components are represented by several rules. We adopt an edge detection algorithm using sobel mask and 8-connected labelling algorith using array pointers. A labeled image has many isolated components. initially, the eye size rules are used. Eye size rules are not affected much by irregular input image conditions. Eye size rules size, and limited in the ratio between gorizontal and vertical sizes. By the eye size rule, 2 ~ 16 candidate eye components can be detected. Next, candidate eye parirs are verified by the information of location and shape, and one eye pair location is decided using face models about eye and eyebrow. Once we extract eye regions, we connect the center points of the two eyes and calculate the angle between them. Then we rotate the face to compensate for the angle so that the two eyes on a horizontal line. We tested 120 input images form 40 people, and achieved 91.7% success rate using eye size rules and face model. The main reasons of the 8.3% failure are due to components adjacent to eyes such as eyebrows. To detect facial components from the failed images, we are developing a mouth region processing module.

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Aging of Solid Fuels Composed of Zr and ZrNi Part 1: Thermal/Chemical/Spectroscopic Analysis (Zr과 ZrNi로 구성된 고체연료의 노화 연구 Part 1: 열/화학/분광학적 분석)

  • Han, Byungheon;Ryu, Jihoon;Yang, Junho;Oh, Juyoung;Gnanaprakash, K.;Yoh, Jai-ick
    • Journal of the Korean Society of Propulsion Engineers
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    • v.24 no.2
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    • pp.1-13
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    • 2020
  • The characterization of aging of the pyrotechnic device is conducted thermally, chemically, and spectroscopically. The device is comprised of two parts: (i) igniter composed of Zr and (ii) pyrotechnic delay composed of ZrNi alloy. The thermally induced chemical reaction is identified through Differential Scanning Calorimetry (DSC) and Thermogravimetry Analysis (TGA). The peak deconvolution of the themo-chemical data is used to estimate the enthalpy change of each metallic fuel component. Laser Induced Breakdown Spectroscopy (LIBS) and X-ray Photoelectron Spectroscopy (XPS) are used for chemical species analysis. The decomposition of oxidants by moisture significantly affected the fuel aging, and the formation of oxide film and metal oxide on the fuel surface gave rise to the thermal energy decrease.

Customized Pattern-Recognition Technique using Vision Measurement System Development in New Car Manufacturing Process (패턴인식 기법을 적용한 신차 제조공정 맞춤식 비젼 계측시스템 개발)

  • Lee, Gyung-Il;Kim, Jae-yeol;Roh, Chi-sung;Choi, Choul Jun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.4
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    • pp.51-59
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    • 2016
  • Measurements of the automobile manufacturers are available anywhere and anytime, directly based on the criterion of failure is measured. The maintenance of high-precision production activities is direct evidence of the fact that competitive manufacturing activities are very important in determining the success of companies to recall defective starting from raw material costs. The current manufacturing sites produce calipers and clearance gauge the degree of tool only specific. Therefore, judging the quality, including the number of errors, requires a lot of attention to the dimension failures in day-to-day measurements and measurement tasks and duties repeated in difficult situations. In this paper, we aim to develop a vehicle manufacturing plant site using each of the manufacturing processes while operating a measurement tool. We display it using the Image Processing PC-based S/W with all those visual facts by management and recorded as image information a more accurate and current situation to obtain information and share visual measurements. We carry out research on the design and development vision inspection algorithm applied for pattern-recognition techniques that can help manufacturing site quality control.