• Title/Summary/Keyword: Resistance Factors

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Calibration of Load and Resistance Factors in KCI Code Based on Domestic Data (국내 통계자료를 이용한 설계기준의 하중저항계수 검증)

  • Kim, Jee-Sang;Kim, Jong-Ho
    • Journal of the Korea Concrete Institute
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    • v.23 no.4
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    • pp.495-501
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    • 2011
  • The load combinations in current KCI Design Code are determined with reference to those in ACI 318-05, which adopts the LRFD (load and resistance factor design) format. The load and resistance factors in LRFD format should be determined to meet the required levels of reliability index or probability of failure for various predetermined failure modes, which are also based on the statistical data reflecting locality and contemporary situation. However, the current KCI Design Code has been written utilizing foreign data, because of insufficiency in accrued data in Korea. This study considered the current safety levels of KCI Code based on published domestic data to evaluate appropriateness of the current KCI regulations. Based on the calibrated reliability index of the existing Code, the new resistance factors are suggested. The results presented in this paper can be considered as a basic research for establishment of unique design format for future Korean Codes.

Resistance to Mobile Commerce Services (모바일상거래 서비스의 저항요인)

  • Song, Hee-Seok;Kim, Kyeong-Cheol
    • The Journal of Society for e-Business Studies
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    • v.11 no.2
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    • pp.111-134
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    • 2006
  • This paper analyzes the resistance to mobile commerce services in consumer adoption process. Relative advantage, compatibility, perceived risk, complexity, self-efficacy, innovativeness and attitude for competing service have been chosen as independent variables. This paper also investigates on the significant factors which resist against adoption of mobile commerce service according to adoption phase. The results show that relative advantage, self-efficacy, perceived risk, attitude for competing service are significant factors to affect resistance to mobile commerce services. Relative advantage, perceived risk, attitude for competing service are significant resistance to mobile commerce services for consumers in before-adoption group and compatibility, complexity, self-efficacy are significant factors for consumers in after-adoption group. This study can be extended to new communication services such as Wibro and DMB to reduce resistances in early adoption phase.

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Investigation of Defense and Vegetative Growth Related Traits of Recombinant Inbred Lines of Brassica rapa

  • Kwon, Soon-Tae;Yeam, Inhwa;Shin, Jong Hwa
    • Korean Journal of Plant Resources
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    • v.33 no.6
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    • pp.615-623
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    • 2020
  • Brassica rapa is one of the most valuable vegetable crops worldwide. Cultivated varieties of B. rapa exhibit diverse developmental and morphological appearances, which includes important vegetables, oilseeds, and fodder crops. In this study, various phenotypes of recombinant inbred lines (RILs) of B. rapa were investigated, including their responses to five different pathogenic Botrytis cinerea isolates, responses to aphid and thrips during flowering stages, days to flowering, and plant heights. Responses of 113 RILs to five different B. cinerea isolates showed variations, suggesting that genetic factors controlling resistance or tolerance against each isolate were dependent on isolate/genotype pairs. Correlation analysis was performed to understand the nature of genetic factors and the relationship among these phenotypes. Although high levels of correlation were not detected between phenotypes assessed in this study, statistically significant correlation was detected for several combinations. Significant positive correlations were found for different B. cinerea isolates, supporting that certain levels of commonality could exist in genetic components controlling resistance against different B. cinerea isolates. Based on correlation analysis using numbers of insects counted on plants, it was speculated that genetic factors responsible for aphid tolerance or repellence might be also involved in the response against thrips. Relationship between vegetative growth and tolerance against B. cinereal or insects is rather more complicated. However, it was observed that shorter plants appeared to have a certain level of tolerance or repellence against both aphids and thrips. Data presented in this study could be used to assist further genetic studies and breeding efforts to obtain Botritis and insect resistance for B. rapa.

Evaluation of the Resistance Bias Factors to Develop LRFD for Driven Steel Pipe Piles (LRFD 설계를 위한 항타강관말뚝의 저항편향계수 산정)

  • Kwak, Kiseok;Park, Jaehyun;Choi, Yongkyu;Huh, Jungwon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.5C
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    • pp.343-350
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    • 2006
  • The resistance bias factors for driven steel pipe piles are evaluated as a part of study to develop the LRFD(Load and Resistance Factor Design) for foundation structures in Korea. The 43 data sets of static load tests and soil property tests performed in the whole domestic area were collected and analyzed to determine the representative bearing capacities of the piles using various methods. Based on the statistical analysis of the data, the Davisson's criterion is proved to be the most reasonable method for estimation of pile bearing capacity among the methods used. The static bearing capacity formulas and the Meyerhof method using N values are applied to calculate the design bearing capacity of the piles. The resistance bias factors of the driven steel pipe piles are evaluated respectively as 0.98 and 1.46 by comparison of the bearing capacities for both of the static bearing capacity formulas and the Meyerhof method. It is also shown that uncertainty of the static bearing capacity formulas is relatively less than that of the Meyerhof method.

Multiple Cases Study on the Motivation, IT Resistance and Change Management for IT Acceptance and Diffusion: focused on Automotive Industry PLM Cases (IT수용 및 확산관련 추진동기, IT저항, 변화관리에 관한 다중사례연구: 자동차산업의 PLM적용사례 중심으로)

  • Han, Seok-Hee;Lee, Yun-Cheol
    • Information Systems Review
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    • v.10 no.3
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    • pp.257-287
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    • 2008
  • Grounded in the prior literatures on acceptance and diffusion of IT and innovation in the level of organization research, 3 major constructional factors such as Motivation, IT resistance, and IT change management were investigated to suggest propositions from 15 multi-cases of PLM from 6 different companies in Automotive OEMs and suppliers, and we posited that the diffusion is continued only when motivation is stronger enough to overcome IT resistance as a fundamental finding and basis of this research on PLM acceptance and diffusion. The Motivation was found to be initiated and categorized from three different factors such as environmental factors, organizational factors, and technological factors, providing key propositions for further research: (1)The Automotive suppliers, contrary to OEM, are affected more by the demand of inter-connectivity as an environmental factor, while the other factors are similarly influencing to them, (2)The big organizations are influenced more by the champion, while the small organizations get influenced more by leader. (3)When the trend, inter-connectivity and complexity get stronger, the motivation gets more strongly influenced by the perceived benefit in the technological context. Regarding Change management we suggests IT change management is supportive to overcome IT resistance and also to enforce Motivation, and the critical mass exists differently according to the market maturity adopted, and more market matured technology has lower critical mass, implies less requirement of IT change management than less market matured technology.

Resolution in Carrier Profiling Semiconductors by Scanning Spreading Resistance Microscopy and Scanning Frequency Comb Microscopy

  • Hagmann, Mark J.;Mousa, Marwan S.;Yarotski, Dmitry A.
    • Applied Microscopy
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    • v.47 no.3
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    • pp.95-100
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    • 2017
  • High resolution measurements of the carrier profile in semiconductor devices is required as the semiconductor industry progresses from the 10-nm lithography node to 7-nm and beyond. We examine the factors which determine the resolution of the present method of scanning spreading resistance microscopy as well as such factors for the newer method of scanning frequency comb microscopy that is now under development. Also, for the first time, we consider the sensitivity of both methods to the location of heterogeneities in the semiconductor. In addition, mesoscopic effects on these measurements are considered for the first time. Two simple analytical models are extended to study the sensitivity to heterogeneities as well as mesoscopic effects.

A Relationship between Smoking and Stress, Vaso-aging degree (자동차 제조회사 근로자를 대상으로 흡연과 스트레스 지수 및 혈관노화도와의 관계)

  • Kim, Seung-Mo;Jung, Hyun-Jung
    • Journal of Society of Preventive Korean Medicine
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    • v.17 no.2
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    • pp.79-88
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    • 2013
  • Objectives : This study investigated the relationship between smoking and health factors including stress resistance, stress index, fatigue and vaso-aging degree. Methods : The subjects were 19,953 persons who had received health examination by Korean Medicine and submitted questionnaires about smoking history, for 8 months from March to November in 2011. The stress index and resistance, fatigue were measured by HRV(Heart Rate Variability). The vaso-aging degree were measured by APG(Accelerated Photoplethysmograph). Results : Regarding the relationship between smoking and stress index and resistance, fatigue and vaso-aging degree were significant differences(p<0.05). Conclusions : This study suggests that smoking affects health factors including stress, fatigue and avaso-aging degree.

Antibiotic Resistance of Escherichia coli Isolated from Hens (계유내(鷄由來) Escherichia coli의 항생물질내성(抗生物質耐性)및 R 인자(因子)의 분포(分布))

  • Tak, Ryunbin
    • Korean Journal of Veterinary Research
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    • v.17 no.1
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    • pp.1-4
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    • 1977
  • Two hundred and twenty-seven strains of Escherichia coli isolated from 25 hens (12 hens received tetracycline neomycin and sulfadimethoxine, and 13 hens not received antibiotics) were studied for the drug resistance and distribution of R factors. About 74 per cent of E. coli strains isolated from hens of a herd received antibiotics were resistance to tetracycline (TC) streptomycin (SM), chloramphenicol (CM), kanamycin (KM), ampicillin (AP) and sulfisomidine (Su), alone or in combination thereof, but only a hen among a herd not received antibiotics excreted E. coli resistant to TC and SM. Among resistant strains, about 7% were found to be resistant to TC and SM, whereas 93% were resistant to three or more antibiotics. The most common pattern was the quadruple resistant to SM, TC, KM and Su (28.7%), and followed by triple ones to SM, TC and Su (25.3%), and SM, TC and KM (24.7%). About 84% of resistant strains carried R factors which were transferable to the recipient by conjugation.

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Reliability analysis of concrete bridges designed with material and member resistance factors

  • Paik, Inyeol;Hwang, Eui-Seung;Shin, Soobong
    • Computers and Concrete
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    • v.6 no.1
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    • pp.59-78
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    • 2009
  • Reliability analysis for a proposed limit state bridge design code is performed. In order to introduce reliability concept to design code, the proposed live load model is based on truck weight survey. Test data of domestic material strengths are collected to model statistical properties of member strengths. Sample RC and PSC girder sections are designed following the safety factor format of the proposed code and compared with the current design practice. Reliability indexes are calculated and examined for material and member resistance factor formats and sample calibrations of safety factors are presented. It is concluded that the proposed code provides reasonable level of reliability compared to the international design standards.

Reliability analysis of tunnels with consideration of the earthquakes extreme events

  • Azadi, Mohammad;Ghasemi, S. Hooman;Mohammadi, Mohammadreza
    • Geomechanics and Engineering
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    • v.22 no.5
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    • pp.433-439
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    • 2020
  • Tunnels are one of the most important constructions in civil engineering. The damage to these structures caused enormous costs. Therefore, the safe and economic design of these structures has long been considered. However, both applied loads on the tunnels as well as the resistance of the structural members are naturally uncertain parameters, hence, the design of these structures requires considering the probabilistic approaches. This study aims to determine the load and resistant factors of lining tunnels concerning the earthquake extreme events limit state function. For this purpose, tunnels that have been designed according to the previous design codes (AASHTO Tunnel LRFD 2017) and using reliability analysis, the optimum reliability of these structures for different loading scenarios is determined. In this paper, the tunnel is considered circular. Finally, the proper load and resistance factors are calculated corresponding to the obtained target reliability. Based on the performed calibration earthquake extreme events limit state function, the result of this study can be recommended to AASHTO Tunnel LRFD 2017.