• Title/Summary/Keyword: scale-model

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Investigation of lateral impact behavior of RC columns

  • Anil, Ozgur;Erdem, R. Tugrul;Tokgoz, Merve Nilay
    • Computers and Concrete
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    • v.22 no.1
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    • pp.123-132
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    • 2018
  • Reinforced concrete (RC) columns which are the main vertical structural members are exposed to several static and dynamic effects such as earthquake and wind. However, impact loading that is sudden impulsive dynamic one is the most effective loading type acting on the RC columns. Impact load is a kind of impulsive dynamic load which is ignored in the design process of RC columns like other structural members. The behavior of reinforced concrete columns under impact loading is an area of research that is still not well understood; however, work in this area continues to be motivated by a broad range of applications. Examples include reinforced concrete structures designed to resist accidental loading scenarios such as falling rock impact; vehicle or ship collisions with buildings, bridges, or offshore facilities; and structures that are used in high-threat or high-hazard applications, such as military fortification structures or nuclear facilities. In this study, free weight falling test setup is developed to investigate the behavior effects on RC columns under impact loading. For this purpose, eight RC column test specimens with 1/3 scale are manufactured. While drop height and mass of the striker are constant, application point of impact loading, stirrup spacing and concrete compression strength are the experimental variables. The time-history of the impact force, the accelerations of two points and the displacement of columns were measured. The crack patterns of RC columns are also observed. In the light of experimental results, low-velocity impact behavior of RC columns were determined and interpreted. Besides, the finite element models of RC columns are generated using ABAQUS software. It is found out that proposed finite element model could be used for evaluation of dynamic responses of RC columns subjected to low-velocity impact load.

Seismic responses of transmission tower-line system under coupled horizontal and tilt ground motion

  • Wei, Wenhui;Hu, Ying;Wang, Hao;Pi, YongLin
    • Earthquakes and Structures
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    • v.17 no.6
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    • pp.635-647
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    • 2019
  • Tests and theoretical studies for seismic responses of a transmission tower-line system under coupled horizontal and tilt (CHT) ground motion were conducted. The method of obtaining the tilt component from seismic motion was based on comparisons from the Fourier spectrum of uncorrected seismic waves. The collected data were then applied in testing and theoretical analysis. Taking an actual transmission tower-line system as the prototype, shaking table tests of the scale model of a single transmission tower and towers-line systems under horizontal, tilt, and CHT ground motions were carried out. Dynamic equations under CHT ground motion were also derived. The additional P-∆ effect caused by tilt motion was considered as an equivalent horizontal lateral force, and it was added into the equations as the excitation. Test results were compared with the theoretical analysis and indicated some useful conclusions. First, the shaking table test results are consistent with the theoretical analysis from improved dynamic equations and proved its correctness. Second, the tilt component of ground motion has great influence on the seismic response of the transmission tower-line system, and the additional P-∆effect caused by the foundation tilt, not only increases the seismic response of the transmission tower-line system, but also leads to a remarkable asymmetric displacement effect. Third, for the tower-line system, transmission lines under ground motion weaken the horizontal displacement and acceleration responses of transmission towers. This weakening effect of transmission lines to the main structure, however, will be decreased with consideration of tilt component.

Shape memory alloy (SMA)-based Superelasticity-assisted Slider (SSS): an engineering solution for practical aseismic isolation with advanced materials

  • Narjabadifam, Peyman;Noori, Mohammad;Cardone, Donatello;Eradat, Rasa;Kiani, Mehrdad
    • Smart Structures and Systems
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    • v.26 no.1
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    • pp.89-102
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    • 2020
  • Shape memory alloy (SMA)-based Superelasticity-assisted Slider (SSS) is proposed as an engineering solution to practically exploit the well-accepted advantages of both sliding isolation and SMA-based recentering. Self-centering capability in SSS is provided by austenitic SMA cables (or wire ropes), recently attracting a lot of interest and attention in earthquake engineering and seismic isolation. The cables are arranged in various novel and conventional configurations to make SSS versatile for aseismic design and retrofit of structures. All the configurations are detailed with thorough technical drawings. It is shown that SSS is applicable without the need for Isolation Units (IUs). IUs, at the same time, are devised for industrialized applications. The proof-of-concept study is carried out through the examination of mechanical behavior in all the alternative configurations. Force-displacement relations are determined. Isolation capabilities are predicted based on the decreases in seismic demands, estimated by the increases in effective periods and equivalent damping ratios. Restoring forces normalized relative to resisting forces are assessed as the criteria for self-centering capabilities. Lengths of SMA cables required in each configuration are calculated to assess the cost and practicality. Practical implementation is realized by setting up a small-scale IU. The effectiveness of SSS under seismic actions is evaluated using an innovative computer model and compared to those of well-known Isolation Systems (ISs) protecting a reference building. Comparisons show that SSS seems to be an effective IS and suitable for earthquake protection of both structural and non-structural elements. Further research aimed at additional validation of the system are outlined.

Health Beliefs of Nursing Faculty Students about Breast Cancer and Self Breast Examination

  • Ardahan, Melek;Dinc, Hulya;Yaman, Askin;Aykir, Emrah;Aslan, Baver
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.17
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    • pp.7731-7736
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    • 2015
  • Background: Breast cancer usually shows a slow development rate and when it is recognized in early stages very successful treatment results can be achieved. This research was planned to research the health beliefs of nursing faculty students about breast cancer and breast self-examination (BSE). Materials and Methods: The first class students of nursing faculty formed the basis for this descriptive research (N=347). Sample selection was not made and all female students who wanted to participate voluntarily in the research during March-May of 2014 were included (n=331). Results: It was determined that 85.5% of students had knowledge about cancer, 79.5 % knew of breast cancer, and 65.3% were aware of how BSE is performed. According to the responses of students to the scale of the health belief model that is used to determine the health beliefs of students, item-point averages of trust and obstacle sub-dimensions were high. Conclusions: It is determined that more than half of students had knowledge about breast cancer and breast self-examination. Their health beliefs were affected by trust and obstacle perceptions, knowledge level about cancer, and awareness about how BSE is done. These factors should be considered in planning trainings that will be given to students. Social responsibility projects should have designed to create the awareness that cancer is a treatable disease.

Knowledge, Behavior and Beliefs Related to Cervical Cancer and Screening Among Turkish Women

  • Reis, Nesrin;Bebis, Hatice;Kose, Sevinc;Sis, Asli;Engin, Raziye;Yavan, Tulay
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1463-1470
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    • 2012
  • Objective: The aims of this study were to explore Turkish women's knowledge, behavior and beliefs related to cervical cancer and screening. Methods: The study was performed in two cities in the East of Turkey between September 2009 and April 2010, with a sampling group of 387 women. Data were collected by means of an interview form with the Health Belief Model Scale for Cervical Cancer and Pap Smear Test - Turkish Version. Results: Women in the research group were found to have poor knowledge, inadequate health behavior and low/medium level false beliefs regarding cervical cancer screening. There was relation between health beliefs and characteristics of women and particularly education (F = 10.80, p = 0.01). Similarly, it was found that Pap smear barriers were influenced by demographic characteristics and that women with low-level education (p = 0.001), divorced women (p = 0.05), women with low-income(p = 0.05), women who gave their first birth when they were 18 or younger (p = 0.05) and women not applying any contraceptive method at all (p = 0.01) were determined to have negative Pap smear barriers. Conclusions: Primarily the knowledge, attitudes and beliefs of women in the target group should be evaluated to increase their participation in cervical cancer screening and to prepare effective education strategies.

Exploratory Investigation of Genetic Associations with Basal Cell Carcinoma Risk: Genome-Wide Association Study in Jeju Island, Korea

  • Yun, Byung Min;Song, Jung-Kook;Lee, Ji-Young
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.17
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    • pp.7443-7447
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    • 2014
  • Aim: Little is known about the genetic associations with Basal cell carcinoma (BCC) risk in non-Caucasian populations, in which BCC is rare, as in Korea. We here conducted a pilot genome-wide association study (GWAS) in 12 patients and 48 standard controls. Method: A total of 263,511 SNPs were analyzed with the Illumina HumanOmni1 Quad v1.0 DNA Analysis BeadChip for cases and Korean HapMap 570K for controls. Results: SNP-based analyses, based on the allele genetic model with adjustment for sex and age showed suggestive associations with BCC risk for 6 SNPs with a P-value (P < 0.0005). However, these associations were not statistically significant after Bonferroni correction: rs1040503, rs2216491, rs13407683, rs4751072, rs9891263, and rs1368474. In addition, results from gene-based analyses showed suggestive associations with BCC risk for 33 candidate genes with a P-value (P <0.0005). Consistent with previous GWAS and replication studies in Caucasian populations, PADI6, RHOU and SLC45A2 were identified as having null associations with BCC (P > 0.05), likely due to the smaller sample size. Conclusions: Although this was a small-scale negative study, to our knowledge, we have conducted the first GWAS for BCC risk in an Asian population. Further large studies in non-Caucasian populations are required to achieve statistical significance and confirm these findings.

A Study on the Information Modeling of Defense R&D Process Using IDEF Methodology (IDEF 방법론을 이용한 국방 연구개발 프로세스의 정보모델링 연구)

  • Kim, Chul-Whan
    • The Journal of Society for e-Business Studies
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    • v.10 no.1
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    • pp.41-60
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    • 2005
  • IDEF(Integrated Definition) method, a standard methodology of CALS process modelling, was applied to the weapon system R&D process to provide information modelling by analysing about goal, input, output and constraints in the R&D process. The information to be managed in R&D institutes was identified by using SmartER which is the automation program of IDEF1/1X and obtained information modelling for TO-BE model. The work process of weapon system R&D consists of the concept study phase, the exploration development phase, the system development phase, the prototype manufacturing phase, and the report writing of R&D results phase. The information modelling of weapon system R&D is the R&D work process with information sharing by means of IWSDB Since IDEF is suitable for large scale system development like weapon system R&D, further studies on IDEF would be required to achieve the goal of defense CALS.

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An Application of GIS Technique to Analyze the Location of Bank Branch Offices : The case of Kangnam-Gu , Seoul (GIS기법을 활용한 은행입지분석에 관한 연구 - 서울시 강남구를 사례로 하여)

  • 이희연;김은미
    • Spatial Information Research
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    • v.5 no.1
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    • pp.11-26
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    • 1997
  • The purpose of this study is to analyze the locational characteristics of bank branch offices in Kangnam-Gu, Seoul by using Geographic Information System. The number of bank branch offices have sharply increased due to financial liberalization, while the scale of them is getting smaller. The procedure of this research has four steps. First, the spatial distribution of bank branch offices in Seoul is analyzed by the places and time. Second, the spatial variations of bank offices in dong districts of Seoul is explained by factor analysis and multiple regression analysis. Third, the location-allocation model which is embedded within network module in Arc/Info is applied in order to find out optimal location of bank offices in Kangnam-Gu. Finally, the grid module is used in creating the potential surface map for locational sites of new bank branch offices The factors to affect the location of the bank offices contain mainly economic variables including local tax, collUl1ercial area, total establismnent and total employment. The actual locational pattern of bank offices is similar to the idealized locational pattern proposed by the function of min-distance in location-allocation models. In conclusion, this study shows that spatial analysis functions may potentially be improved using GIS technologies. However in order to analyze the location of bank offices more precisely, it should be found out the way to collect more appropriate data, construct computerized base maps, and investigate consumer behaviour and behavioural characteristics of bank themselves..

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A Study on Auto Inspection System of Cross Coil Movement Using Machine Vision (머신비젼을 이용한 Cross Coil Movement 자동검사 시스템에 관한 연구)

  • Lee, Chul-Hun;Seol, Sung-Wook;Joo, Jae-Heum;Lee, Sang-Chan;Nam, Ki-Gon
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.11
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    • pp.79-88
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    • 1999
  • In this paper we address the tracking method which tracks only target object in image sequence including moving object. We use a contour tracking algorithm based on intensity and motion boundaries. The motion of the moving object contour in the image is assumed to be well describable by an affine motion model with a translation, a change in scale and a rotation. The moving object contour is represented by B-spline, the position and motion of which is estimated along the image sequence. we use pattern recognition to identify target object. In order to use linear Kalman Filters we decompose the estimation process into two filters. One is estimating the affine motion parameters and the other the shape of moving object contour. In some experiments with dial plate we show that this method enables us to obtain the robust motion estimates and tracking trajectories even in case of including obstructive object.

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Dynamic Voltage Scaling (DVS) Considering the DC-DC Converter in Portable Embedded Systems (휴대용 내장형 시스템에서 DC-DC 변환기를 고려한 동적 전압 조절 (DVS) 기법)

  • Choi, Yong-Seok;Chang, Nae-Hyuck;Kim, Tae-Whan
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.2
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    • pp.95-103
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    • 2007
  • Dynamic voltage scaling (DVS) is a well-known and effective power management technique. While there has been research on slack distribution, voltage allocation and other aspects of DVS, its effects on non-voltage-scalable devices has hardly been considered. A DC-DC converter plays an important role in voltage generation and regulation in most embedded systems, and is an essential component in DVS-enabled systems that scale supply voltage dynamically. We introduce a power consumption model of DC-DC converters and analyze the energy consumption of the system including the DC-DC converter. We propose an energy-optimal off-line DVS scheduling algorithm for systems with DC-DC converters, and show experimentally that our algorithm outperforms existing DVS algorithms in terms of energy consumption.