• Title/Summary/Keyword: Resistance Factors

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Basic Design for Earthquake Resistance of Typical Bridges (일반교량의 내진성능 확보를 위한 기본설계)

  • Kook, Seung-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.1
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    • pp.49-57
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    • 2013
  • Structural elements of typical bridges are superstructure, connections, substuctures and foundations and earthquake resistance is decided with the failure mechanism formed by substuctures and connections. Therefore earthquake resistant design should be carried out in the basic design step where design strengths, e.g. design sections for structural elements are determined. The Earthquake Resistant Design Part of Korean Roadway Bridge Design Code provides two basic design procedures. The first conventional procedure applies the Code-provided response modification factors. The second new procedure is the ductility-based earthquake resistant design, where designer can determine the response modification factors. In this study, basic designs including the two design processes are carried out for a typical bridge and supplements are identified in view of providing earthquake resistance.

Why Do Laggards Resist the IT Adoption in Public Service? : A Case of Expressway Hi-Pass System (공공서비스 IT수용에 대한 사용자 저항요인 : 고속도로 하이패스시스템 사례)

  • Cho, Hee-Soo;Suh, Yung-Ho;Lee, Sang-Chul;Lee, Sae-Bom
    • Journal of Korean Society for Quality Management
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    • v.47 no.2
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    • pp.367-380
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    • 2019
  • Purpose: The purpose of this study is (1) to empirically examine why laggards resist IT adoption in public service and (2) to investigate the relationship between resistance and negative behavioral intention. Methods: The questionnaire survey was conducted on expressway users who do not use High-pass system. The collected 232 samples were analyzed using structure equation model method with AMOS 22.0. Results: Resistance is found to be a statistically significant factor affecting intention to reject. Also, incompatibility, privacy concern, status quo inertia and relative advantage are found to be statistically significant factors affecting resistance. Conclusion: Laggards have a tendency to intend to reject IT adoption rather than to postpone. They are affected not by monetary, procedural aspect associated with purchasing or registering OBU(On Board Unit). Incompatibility and relative advantage which are inherent attributes of Hi-pass system are more influential factors than privacy concern and status quo inertia. They make ethical and emotional decision partially affected by public-social factors.

A Study of Intention to Use Wrist-worn Wearable Devices Based on Innovation Resistance Model - Focusing on the Relationship between Innovation Characteristics, Consumer Characteristics, and Innovation Resistance (혁신저항 모형에 기반한 손목형 웨어러블 디바이스의 수용의도 연구 - 혁신특성, 소비자 특성, 혁신저항을 중심으로)

  • Shin, Jae-Gwon;Lee, Sang-Woo
    • The Journal of the Korea Contents Association
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    • v.16 no.6
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    • pp.123-134
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    • 2016
  • As the internet of things has come into the spotlight, wearable devices have been emerging as a new and growing market and the next hot thing in the world. However, wearable device growth in the market has not met expectations. For continued growth and diffusion of wearable devices, it is important to investigate user resistance factors to them. This study gives attention to people who have resistance to wearable devices' tendency towards innovative uses. Specifically, this study is intended to find out which factors influence consumers' resistance and intention to use wrist-worn wearable devices, which are in high demand among wearable device. Results of the study show that the relative advantage, innovation expectation, complexity, financial risk and physical risk are the predictors of innovation resistance on wrist-worn wearable devices. And consumers' resistance affects the intention of positive acceptance. These findings confirm the importance of consumer resistance to the wrist-worn wearable device.

Factors influencing the bio-impedance data in tissue segments along the three arm meridians: a pilot study

  • Lim, Chi Eung Danforn;Wong, Felix Wu Shun;Smith, Warren
    • CELLMED
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    • v.1 no.1
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    • pp.7.1-7.9
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    • 2011
  • Bioelectric impedance measurements have been reported to show significant variation between individuals. Different physiological conditions like thickened skin, obesity, and fluid retention can affect the impedance measurement. Therefore, it is important to learn what other factors can affect the measurements of impedance even in healthy individuals. Such information is a prerequisite for understanding the changes in impedance associated with acupuncture treatment. This study investigated the bio-impedance properties of tissue segments in the arms of a number of healthy subjects, so as to define the factors that might influence the variation of the bio-impedance data in acupuncture meridians studies. 51 healthy subjects were recruited through Liverpool Hospital, Sydney. Demographic data was collected from each subject including the age, sex, BMI, and time since most recent meal. Electrodes were applied to the forearms of each test subject. Measurements were done by a purpose-built Bio-Impedance Research Device (BIRD-I) which allowed the determination of core resistance (Rc) and core reactance (Xc) of each of the three meridian tissue segments on the anterior surface of the forearm. No significant difference was found in the core resistance attributable to age group, gender, BMI or meal intake. However, a statistically significant trend in increasing resistance from the radial to ulnar aspect of the forearm (p < 0.001) was found. No significant difference was found in the core resistance of test tissue segments among the 51 healthy subjects measured in this study. However, the trend of increasing core resistance from the radial to ulnar aspects of the arm deserves further investigation.

An Experimental Study about Fire Resistance effect on Boundary Condition of CFT Column under Loading in Fire (CFT기둥 재하가열 실험에서의 경계조건에 따른 내화성능 영향에 관한 실험적 연구)

  • Kim, Hyung-Jun;Kim, Heung-Youl;Park, Kyung-Hun;Cho, Kyung-Suk;Kwon, In-Kyu
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2010.04a
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    • pp.389-394
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    • 2010
  • A concrete filled square steel tube (CFT) is composed of the external steel material, which its strength is reduced in fire due to sudden temperature increase, and the internal concrete with high thermal capacity that can ensure the fire resistance performance of the structure. Therefore, research about the influence factors of the structural performance of CFT column is required in order to apply CFT column to a fire resisting structure, and additional research about influence for each condition is also necessary. Among the influence factors, the boundary condition between column and beam is important structurally, and it is one of the major factors that determine overall fire resisting performance. This study performed a fire experiment under loading in order to analyse the influences of CFT column to the boundary condition. As the results of the experiment, fire resistance time of 106 minutes was ensured for the clamped-end condition but 89 minutes for the hinge-end condition in case of the 360 cross section. And, fire resistance time of 113 minutes was ensured for the clamped-end condition but 78 minutes for the hinge-end condition in case of the 280 cross section. The difference in the fire resistance performance according to changes in the boundary conditions showed a tendency that larger change effect on the fire resistance performance was derived from smaller cross section area.

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Evaluation of Reliability Index of Governing Load Combination for Design of Cable Supported Bridge Members (케이블교량의 부재 설계를 지배하는 하중조합에 대한 신뢰도지수 평가)

  • Paik, Inyeol;Yoon, Taeyong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.6
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    • pp.643-651
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    • 2014
  • In this paper the reliability analyses of the cable-supported bridge design code which is recently issued in Korea are performed and the results are presented. Governing load combinations for the member design and the statistical properties of the main members are introduced and the analysis is performed using an example cable-stayed bridge for which the design is performed following the load and resistance factors defined in the design code. The reliability analysis shows the target reliability index can be achieved by applying load and resistance factors and the application of the resistance modification factor can enhance the reliability level if the importance of the bridge needs to be increased. The sensitivity analysis reveals that decreasing uncertainty of the cable strength is critical for obtaining the target reliability index. The study results show that the design using the load and resistance factors of the code can achieve the target reliability indexes for the design of cable supported bridge.

Molecular Characteristics and Exotoxins of Methicillin-Resistant Staphylococcus aureus

  • Bae, Jinyoung;Jin, Hyunwoo;Kim, Jungho;Park, Min;Lee, Jiyoung;Kim, Sunghyun
    • Biomedical Science Letters
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    • v.27 no.4
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    • pp.195-207
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    • 2021
  • Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial pathogen capable of causing human diseases, such as soft tissue infection, bacteremia, endocarditis, toxic shock syndrome, pneumonia, and sepsis. Although the incidence rate of diseases caused by MRSA has declined in recent years, these diseases still pose a clinical threat due to their consistently high morbidity and mortality rates. However, the role of virulence factors in staphylococcal infections remains incompletely understood. Methicillin resistance, which confers resistance to all β-lactam antibiotics in cellular islets, is mediated by the mecA gene in the staphylococcal cassette chromosome mec (SCCmec). Differences in SCCmec types and differences in their sizes and structures serve epidemiological purposes and are used to differentiate between hospital-associated (HA)-MRSA and community-associated (CA)-MRSA. Some virulence factors of S. aureus are also providing a distinction between HA-MRSA and CA-MRSA. These factors vary depending on the presence of toxins, adhesion, immune evasion, and other virulence determinants. In this review, we summarized an overview of MRSA such as resistance mechanisms, SCCmec types, HA- and CA-MRSA, and virulence factors that enhance pathogenicity or MRSA epidemiology, transmission, and genetic diversity.

Evaluation of partial safety factors of Hudson formula for Tetrapod armor units constructed in Korea (국내에서 시공된 Tetrapod 피복재에 대한 Hudson 공식의 부분안전계수 산정)

  • Kim, Seung-Woo;Suh, Kyung-Duck
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.21 no.5
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    • pp.345-356
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    • 2009
  • Tetrapod has been used as the armor blocks of most rubble mound breakwaters constructed in Korea. The Hudson formula has been widely used in the design of breakwater armor blocks in Korea. In the present study, we calculate the load and resistance partial safety factors of the Hudson formula for Tetrapod armors. The partial safety factors were calculated for the typical breakwater cross-sections of 12 trade harbors and 8 coastal harbors in Korea. The mean and standard deviation of them were also calculated. The mean values were compared with the partial safety factors of US Army (2006). The load and resistance factors are slightly smaller and larger, respectively, than the US Army values. However, the overall safety factors obtained by multiplying the load and resistance factors are close to the US Army values. The result of the present study could be used as the basic data to propose authorized partial safety factors in the future.

Reliability Updates of Driven Piles Using Proof Pile Load Test Results (검증용 정재하시험 자료를 이용한 항타강관말뚝의 신뢰성 평가)

  • Park, Jae-Hyun;Kim, Dong-Wook;Kwak, Ki-Seok;Chung, Moon-Kyung;Kim, Jun-Young;Chung, Choong-Ki
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.324-337
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    • 2010
  • For the development of load and resistance factor design, reliability analysis is required to calibrate resistance factors in the framework of reliability theory. The distribution of measured-to-predicted pile resistance ratio was constructed based on only the results of load tests conducted to failure for the assessment of uncertainty regarding pile resistance and used in the conventional reliability analysis. In other words, successful pile load test (piles resisted twice their design loads without failure) results were discarded, and therefore, were not reflected in the reliability analysis. In this paper, a new systematic method based on Bayesian theory is used to update reliability index of driven steel pile piles by adding more pile load test results, even not conducted to failure, into the prior distribution of pile resistance ratio. Fifty seven static pile load tests performed to failure in Korea were compiled for the construction of prior distribution of pile resistance ratio. Reliability analyses were performed using the updated distribution of pile resistance ratio and the total load distribution using First-order Reliability Method (FORM). The challenge of this study is that the distribution updates of pile resistance ratio are possible using the load test results even not conducted to failure, and that Bayesian update are most effective when limited data are available for reliability analysis or resistance factors calibration.

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