• Title/Summary/Keyword: Fail-Safety

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Consumer Perspectives and Utilization of Drug Information in Korea (국내 의약품정보에 대한 소비자의 시각 및 활용도)

  • Lee, Iyn-Hyang;Kye, Seunghee;Lee, Sukhyang
    • Korean Journal of Clinical Pharmacy
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    • v.23 no.4
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    • pp.334-343
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    • 2013
  • Purpose: This study aims to investigate consumers' demand of and perspective on drug information domestically available and uncover hurdles that they faced while utilizing information. Methods: We conducted a survey of 101 consumers, face-to-face after obtaining informed consent. Chi-squared, or Fisher's exact tests, and multivariate logistic models were used to investigate the association between participants' perceptions and characteristics. Results: As results, participants showed the highest demand for "Adverse effects >90%"; "Drug interactions/Dosage/Drug-food interactions/Indication >80%", and utilized package inserts (52%), doctors (41%) and pharmacists (36%) most often as information sources. Generally, the most common difficulty consumers suffered with was that "it is hard to understand (51%)". With public sources of drug information, sixty one percent of participants were "unaware of the provision of information", resulting in strikingly low usage rates (5~11%). Subgroup analyses indicated that the older (${\geq}50$ years) and the disadvantaged might have been placed in the blind spot of information mostly developed online (p<0.05).Conclusion: In conclusion, public sources of drug information that have been developed online might fail to meet consumers' demand. Greater efforts should be made to balance the development of the information sources between online and offline, and to increase accessibility of the established information sources.

A STUDY ON THE FATIGUE LIFE PREDICTION OF GUIDEWAY VEHICLE COMPONENTS (안내궤도 차량 부품의 피로 수명 예측에 관한 연구)

  • Lee, Soo-Ho;Park, Tae-Won;Yoon, Ji-Won;Jeon, Yong-Ho;Jung, Sung-Pil;Park, Joong-kyung
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.997-1002
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    • 2007
  • A guideway vehicle is used in automobile, semiconductor and LCD manufacturing industries to transport products efficiently. Since the operating speed of the guideway vehicle should be increased for maximum productivity, the weight of the vehicle has to be reduced. This may cause parts in the system to fail before the life of the system. Therefore estimation of the fatigue life of the parts becomes an important problem. In this study, the fatigue life of the driving wheel in the guideway vehicle is estimated using a S-N curve. To obtain the fatigue life of a part, the S-N curve, load time history applied on a driving wheel and material property are required. The S-N curve of the driving wheel is obtained using the fatigue experiment on wheels. Load time history of the wheel is obtained from multibody dynamics analysis. To obtain the material properties of the driving wheel, which is composed of aluminum with urethane coating, a compression hardware testing has been done with the static analysis of the FE model. The fatigue life prediction using computational analysis model guarantees the safety of the vehicle at the design stage of the product.

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Structural behavior of cable-stayed bridges after cable failure

  • Kim, Seungjun;Kang, Young Jong
    • Structural Engineering and Mechanics
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    • v.59 no.6
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    • pp.1095-1120
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    • 2016
  • This paper investigates the change of structural characteristics of steel cable-stayed bridges after cable failure. Cables, considered as the intermediate supports of cable-stayed bridges, can break or fail for several reasons, such as fire, direct vehicle clash accident, extreme weather conditions, and fatigue of cable or anchorage. Also, the replacement of cables can cause temporary disconnection. Because of the structural characteristics with various geometric nonlinearities of cable-stayed bridges, cable failure may cause significant change to the structural state and ultimate behavior. Until now, the characteristics of structural behavior after cable failure have rarely been studied. In this study, rational cable failure analysis is suggested to trace the new equilibrium with structural configuration after the cable failure. Also, the sequence of ultimate analysis for the structure that suffers cable failure is suggested, to study the change of ultimate behavior and load carrying capacity under specific live load conditions. Using these analysis methods, the statical behavior after individual cable failure is studied based on the change of structural configuration, and distribution of internal forces. Also, the change of the ultimate behavior and load carrying capacity under specific live load conditions is investigated, using the proposed analysis method. According to the study, significant change of the statical behavior and ultimate capacity occurs although just one cable fails.

Case Study of Intermittent Poor Acceleration Fault Diagnosis by Brake Switch Fault (브레이크 스위치 결함에 의한 간헐적인 가속불량 현상의 고장진단 사례연구)

  • Kim, Sung Mo;Jo, Haeng Deug
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.2
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    • pp.203-210
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    • 2015
  • This paper investigates the failure of a car with a 2.5-liter CRDi engine of the Hyundai Company. The failure is caused by intermittent poor acceleration while driving. To analyze the cause, we investigated the air intake volume, the fuel injection, and the air-fuel ratio, which were determined to be normal. The brake switch signal error was discovered while analyzing the function that limits the output of the engine. While investigating the cause, we discovered the corrosion of the pins on the connector of the brake switch. We determined that it was generated by soapy water flowing in the solar film. Therefore, the cause of the failure was the brake switch signal errors. Additionally, we determined that ECM was the normal fail-safe mode that implemented the override device for safety during normal acceleration. Based on these results, further solar film experiments must be conducted to fully elucidate the causes.

Advanced Reactor Passive System Reliability Demonstration Analysis for an External Event

  • Bucknor, Matthew;Grabaskas, David;Brunett, Acacia J.;Grelle, Austin
    • Nuclear Engineering and Technology
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    • v.49 no.2
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    • pp.360-372
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    • 2017
  • Many advanced reactor designs rely on passive systems to fulfill safety functions during accident sequences. These systems depend heavily on boundary conditions to induce a motive force, meaning the system can fail to operate as intended because of deviations in boundary conditions, rather than as the result of physical failures. Furthermore, passive systems may operate in intermediate or degraded modes. These factors make passive system operation difficult to characterize within a traditional probabilistic framework that only recognizes discrete operating modes and does not allow for the explicit consideration of time-dependent boundary conditions. Argonne National Laboratory has been examining various methodologies for assessing passive system reliability within a probabilistic risk assessment for a station blackout event at an advanced small modular reactor. This paper provides an overview of a passive system reliability demonstration analysis for an external event. Considering an earthquake with the possibility of site flooding, the analysis focuses on the behavior of the passive Reactor Cavity Cooling System following potential physical damage and system flooding. The assessment approach seeks to combine mechanistic and simulation-based methods to leverage the benefits of the simulation-based approach without the need to substantially deviate from conventional probabilistic risk assessment techniques. Although this study is presented as only an example analysis, the results appear to demonstrate a high level of reliability of the Reactor Cavity Cooling System (and the reactor system in general) for the postulated transient event.

Radiotherapy for Benign Diseases (양성질환의 방사선치료)

  • Choi, Sang Gyu
    • Journal of the Korean Society of Radiology
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    • v.10 no.8
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    • pp.611-618
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    • 2016
  • Radiotherapy, as a major 3 standard treatment for cancer, traditionally it has been useful treatment that aim of curative or palliative setting. In addition to some proliferative or inflammatory benign disease are also included in field of radiotherapy. Unlike cancer, in the case of benign disease, it shows good treatment result from usage of some medication, conservative management or surgery. But if fail of these treatment or impossible, low dose radiotherapy is use adjuvant or replacement treatment so that there are no harmful side effect result in safety and easy management for reduce pain or recurrence. Recently, the technical advances in radiotherapy that have been achieved make preservation of normal tissue and the clinical application of high precision radiotherapy focus to selective lesions is possible, and it makes useful treatment in senile patients especially.

Design and stress analysis of femur bone implant with composite plates

  • Ramakrishna, S.;Pavani, B.
    • Biomaterials and Biomechanics in Bioengineering
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    • v.5 no.1
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    • pp.37-50
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    • 2020
  • Development of lightweight implant plates are important to reduce the stress shielding effect for a prosthesis of femur bone fractures. Stainless steel (SS-316L) is a widely used material for making implants. Stress shielding effect and other issues arise due to the difference in mechanical properties of stainless steel when compared with bone. To overcome these issues, composite materials seem to be a better alternative solution. The comparison is made between two biocompatible composite materials, namely Ti-hydroxyapatite and Ti-polypropylene. "Titanium (Ti)" is fiber material while "hydroxyapatite" and "polypropylene" are matrix materials. These two composites have Young's modulus closer to the bone than stainless steel. Besides the variety of bones, present paper constrained to femur bone analysis only. Being heaviest and longest, the femur is the most likely to fail among all bone failures in human. Modelling of the femur bone, screws, implant and assembly was carried out using CATIA and static analysis was carried out using ANSYS. The femur bone assembly was analyzed for forces during daily activities. Ti-hydroxyapatite and Ti-polypropylene composite implants induced more stress in composite implant plate, results less stress induced in bone leading to a reduction in shielding effect than stainless steel implant plate thus ensuring safety and quick healing for the patient.

THERMAL HYDRAULIC ISSUES OF CONTAINMENT FILTERED VENTING SYSTEM FOR A LONG OPERATING TIME

  • Na, Young Su;Ha, Kwang Soon;Park, Rae-Joon;Park, Jong-Hwa;Cho, Song-Won
    • Nuclear Engineering and Technology
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    • v.46 no.6
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    • pp.797-802
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    • 2014
  • This study investigated the thermal hydraulic issues in the Containment Filtered Venting System (CFVS) for a long operating time using the MELCOR computer code. The modeling of the CFVS, including the models for pool scrubbing and the filter, was added to the input file for the OPR-1000, and a Station Blackout (SBO) was chosen as an accident scenario. Although depressurization in the containment building as a primary objective of the CFVS was successful, the decontamination feature by scrubbing and filtering in the CFVS for a long operating time could fail by the continuous evaporation of the scrubbing solution. After the operation of the CFVS, the atmosphere temperature in the CFVS became slightly above the water saturation temperature owing to the release of an amount of steam with high temperature from the containment building to the scrubbing solution. Reduced pipe diameters at the inlet and outlet of the CFVS vessel mitigated the evaporation of scrubbing water by controlling the amount of high-temperature steam and the water saturation temperature.

Development of a Fault-Tolerant Steer-By-Wire Control System (Fault-Tolerant Steer-By-Wire 제어 시스템의 개발)

  • Kim, Jae-Suk;Hwang, Woon-Gi;Lee, Woon-Sung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.5
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    • pp.1-8
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    • 2006
  • The Steer-By-Wire(SBW) system replaces complex mechanical linkages of the current steering system with electric motors, sensors, and electronic control units. However, the SBW system should guarantee its safety and reliability before commercialization, and therefore, a reliable and robust fault-tolerant technology has to be implemented. This paper proposes a fault-tolerant control algorithm for the SBW system. Based on careful analysis on propagation effects of sensor faults, a reliable fault-tolerant control strategy has been developed. The fault-tolerant controller consists of a fault detection part that monitors and detects faults in the steering wheel and road wheel sensors, and a reconfiguration part that switches to normal sensor signal based on fault detection information. It has been demonstrated by simulation that the proposed algorithm detects sensor faults accurately and enables reliable steering control under various dynamic fault situations.

Analysis of Failure Behavior of Pile Embedded in Liquefiable Soil Deposits considering Buckling Instability (좌굴을 고려한 액상화 지반에 근입된 말뚝의 파괴거동 분석)

  • Han, Jin-Tae;Cho, Chong-Suck;Hwang, Jae-Ik;Kim, Myoung-Mo
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.105-112
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    • 2006
  • Liquefaction-induced lateral spreading has been the most extensive damage to pile foundations during earthquakes. However, a case of pile failure was reported despite the fact that a large margin of safety factor was employed in their design. This means that the current seismic design method of pile is not agreeable with the actual failure mechanism of pile. Newly proposed failure mechanism of pile is a pile failure based on buckling instability. In this study, failure behavior of pile embedded in liquefied soil deposits was analyzed considering lateral spreading and buckling instability performing 1g shaking table test. As a result, it can be concluded that the pile subjected to excessive axial loads ($near\;P_{cr}$) can fail by buckling instability during liquefaction. When lateral spreading took place in sloping grounds, lateral spreading increased lateral deflection of pile and reduced the buckling load, promoting more rapid collapse. In addition, buckling shape of pile was observed. In the ease of pile buckling, hinge formed at the middle of the pile, not at the bottom. And in sloping grounds, location of hinge got loiter compared with level ground because of the effects of lateral spreading.

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