• Title/Summary/Keyword: directivity effects

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Effects of revolutional leadership of manager at private security service organization members learning directivity and organizational innovation behavior (민간경비 경영자의 변혁적리더십이 구성원의 학습지향성 및 조직혁신 행동에 미치는 영향)

  • Kang, Minwan
    • Journal of the Society of Disaster Information
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    • v.10 no.2
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    • pp.264-273
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    • 2014
  • The purpose of the study is to demonstrate the effects of revolutional leadership of manager at private security organization on members' learning directivity and organizational innovation behavior. The results attained from studying method and procedure as mentioned above are in the following. First, the revolutional leadership of manager at private security service organization influence learning directivity. That is, the more he or she shows revolutional leadership, the more enhanced the learning directivity of members. Second, the revolutional leadership of manager at private security service organization has effects on organizational innovation behavior. Thatis, the more he or she shows revolutional leadership the more enhanced organizational innovation behavior. Third, learning directivity of manager at private securitys service organization influences organizational innovation behavior. Thatis, the more he or she shows learning directivity, the more enhanced organizational innovation behavior. Taken all, revolutional leadership of manager at private security service organization affects organizational innovation behavior through learning directivity. It is shown that learning directivity is a key variable connecting revoultional leadership with organization al innovation behavior.

Effects of near-fault records characteristics on seismic performance of eccentrically braced frames

  • Eskandari, Reyhaneh;Vafaei, Davoud
    • Structural Engineering and Mechanics
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    • v.56 no.5
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    • pp.855-870
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    • 2015
  • In this paper the effects of fling-step and forward-directivity on the seismic performance of steel eccentrically braced frames (EBFs) are addressed. Four EBFs with various numbers of stories (4-, 8-, 12- and 15-story) were designed for an area with high seismic hazard. Fourteen near-fault ground motions including seven with forward-directivity and seven with fling-step effects are selected to carry out nonlinear time history (NTH) analyses of the frames. Furthermore, seven more far-field records were selected for comparison. Findings from the study reveal that the median maximum links rotation of the frames subjected to three set of ground motions are in acceptable range and the links completely satisfy the requirement stated in FEMA 356 for LS performance level. The arrival of the velocity pulse in a near-fault record causes few significant plastic deformations, while many reversed inelastic cycles result in low-cycle fatigue damage in far-fault records. Near-fault records in some cases are more destructive and the results of these records are so dispersed, especially the records having fling-step effects.

Effects of pulse-like nature of forward directivity ground motions on the seismic behavior of steel moment frames

  • Mansouri, Iman;Shahbazi, Shahrokh;Hu, Jong Wan;Moghaddam, Salar Arian
    • Earthquakes and Structures
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    • v.17 no.1
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    • pp.1-15
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    • 2019
  • In the structures with high level of ductility, the earthquake energy dissipation in structural components is an important factor that describes their seismic behavior. Since the connection details play a major role in the ductile behavior of structure, in this paper, the seismic response of 3-, 5- and 8-story steel special moment frames (SMFs) is investigated by considering the effects of panel zone modeling and the influence of forward-directivity near-field ground motions. To provide a reasonable comparison, selected records of both near and far-field are used in the nonlinear time-history analysis of models. The results of the comparison of the median maximum inter-story drift under excitation by near-field (NF) records and the far-field (FF) ground motions show that the inter-story drift demands can be obtained 3.47, 4.86 and 5.92 times in 3-, 5- and 8-story structures, respectively, undergoing near-field earthquakes.

The effects of peak ground velocity of near-field ground motions on the seismic responses of base-isolated structures mounted on friction bearings

  • Tajammolian, H.;Khoshnoudian, F.;Talaei, S.;Loghman, V.
    • Earthquakes and Structures
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    • v.7 no.6
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    • pp.1259-1281
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    • 2014
  • This research has been conducted in order to investigate the effects of peak ground velocity (PGV) of near-field earthquakes on base-isolated structures mounted on Single Friction Pendulum (SFP), Double Concave Friction Pendulum (DCFP) and Triple Concave Friction Pendulum (TCFP) bearings. Seismic responses of base-isolated structures subjected to simplified near field pulses including the forward directivity and the fling step pulses are considered in this study. Behaviour of a two dimensional single story structure mounting on SFP, DCFP and TCFP isolators investigated employing a variety range of isolators and the velocity (PGV) of the forward directivity and the fling step pulses as the main variables of the near field earthquakes. The maximum isolator displacement and base shear are selected as main seismic responses. Peak seismic responses of different isolator types are compared to emphasize the efficiency of each one under near field earthquakes. It is demonstrated that rising the PGVs increases the isolator displacement and base shear of structure. The effects of the forward directivity are greater than the fling step pulses. Furthermore, TCFP isolator is more effective to control the near field effects than the other friction pendulum isolators are. This efficiency is more significant in pulses with longer period and greater PGVs.

Strong ground motion characteristics of the 2011 Van Earthquake of Turkey: Implications of seismological aspects on engineering parameters

  • Beyen, Kemal;Tanircan, Gulum
    • Earthquakes and Structures
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    • v.8 no.6
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    • pp.1363-1386
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    • 2015
  • The October 23 2011 Van Earthquake is studied from an earthquake engineering point of view. Strong ground motion processing was performed to investigate features of the earthquake source, forward directivity effects during the rupture process as well as local site effects. Strong motion characteristics were investigated in terms of peak ground motion and spectral acceleration values. Directiviy effects were discussed in detail via elastic response spectra and wide band spectograms to see the high frequency energy distributions. Source parameters and slip distribution results of the earthquake which had been proposed by different researchers were summarized. Influence of the source parameters on structural response were shown by comparing elastic response spectra of Muradiye synthetic records which were performed by broadband strong motion simulations of the earthquake. It has been emphasized that characteristics of the earthquake rupture dynamics and their effects on structural design might be investigated from a multidisciplinary point of view. Seismotectonic calculations (e.g., slip pattern, rupture velocity) may be extended relating different engineering parameters (e.g., interstorey drifts, spectral accelerations) across different disciplines while using code based seismic design approaches. Current state of the art building codes still far from fully reflecting earthquake source related parameters into design rules. Some of those deficiencies and recent efforts to overcome these problems were also mentioned. Next generation ground motion prediction equations (GMPEs) may be incorporated with certain site categories for site effects. Likewise in the 2011 Van Earthquake, Reverse/Oblique earthquakes indicate that GMPEs need to be feasible to a wider range of magnitudes and distances in engineering practice. Due to the reverse faulting with large slip and dip angles, vertical displacements along with directivity and fault normal effects might significantly affect the engineering structures. Main reason of excessive damage in the town of Erciş can be attributed to these factors. Such effects should be considered in advance through the establishment of vertical design spectra and effects might be incorporated in the available GMPEs.

The Effects of the Restaurateur Quality and Skill on Performance in Small Business (소규모 외식업체 경영자의 자질이 경영성과에 미치는 영향)

  • Paik, Jin-Kyoung;Sohn, Chun-Young;Park, Dae-Seob;Hong, Wan-Soo
    • The Korean Journal of Food And Nutrition
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    • v.25 no.4
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    • pp.1039-1046
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    • 2012
  • The purpose of this study was to lay emphasis on the importance of a restaurateur's role and qualities as well as to provide the restaurateur information necessary to effectively run a restaurant. To address the purpose, this study analyzed the qualities of a restaurateur and determined the influence they have on the business results, via conducting a survey with 117 restaurateurs from June 11th to June 26th 2011. In summary, male restaurateurs were higher in the vision directivity, desire to learn, accomplishment, challenge and pro-activity than their female counterparts, with a significant difference of p<0.05. According to their ages, the surveyees showed significant differences in the vision directivity (p<0.05), desire to learn (p<0.01), challenge (p<0.01) and pro-activity (p<0.01). In addition, also the survey revealed that the qualities of a restaurateur had a significant influence on financial performance, a sense of satisfaction and business results (p<0.001). The questionnaire resulted in the following: first, the vision directivity (p<0.05) and the challenge (p<0.05) affected the financial performance; second, the challenge had influence on the sense of satisfaction; and last, the vision directivity (p<0.05) and the challenge (p<0.05) had an effect on the business results. Thus, the study concluded that restaurateurs need two qualities: (i) the vision directivity in order to meet their goals and to have a higher business results and (ii) the challenge to try new managing methods in order to cope with the ever-changing environment.

A Tendency of Prediction Technique for the Assessment of Railway Noise (철도소음 영향평가를 위한 예측기술 동향)

  • Cho, Jun-Ho;Park, Young-Min;Sun, Hyo-Sung;Hong, Woong-Gi
    • Journal of Environmental Impact Assessment
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    • v.16 no.1
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    • pp.99-105
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    • 2007
  • Since 1990s, the railway noise has been researched and developed in our nation. First of all, what's causing the noise and how to eliminate the cause of the noise must be found out. Secondly, cutting off the propagation path of the noise from the noise source to the receiving points. In this study the characteristics of prediction formula for the assessment of railway noise used in some nations including Korea were investigated. In order to develop the prediction formula of the railway noise, the noise radiated from railway vehicle, rails and sleepers, characteristics of noise barrier, velocity of train, ground effects, roughness should be analyzed and predicted. Especially, on the basis of acoustics, the characteristics of source are applied to acoustic power and directivity information.

Principles and Considerations of Bender Element Tests (벤더엘리먼트 시험의 원리와 고려사항)

  • Lee Jong-Sub;Lee Chang-Ho
    • Journal of the Korean Geotechnical Society
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    • v.22 no.5
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    • pp.47-57
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    • 2006
  • The shear wave velocity is related with the stiffness of granular skeleton and mass density. The shear stiffness of the granular skeleton remains unaffected by the presence of the fluid. Bender elements are convenient shear wave transducers for instrumenting soil cells due to optimal soil-transducer coupling. This study addresses the principles of the shear wave, the design and implementation of bender elements including electromagnetic coupling prevention, directivity, resonant frequency, detection of first arrival, and near field effects. It is shown that electromagnetic coupling effects can be minimized using parallel-type bender elements. Thus, the in-plane S-wave directivity is quasi-circular. The resonant frequency of bender element installations depends on the geometry of the bender element, the anchor efficiency and the soil stiffness. One of the most cumbersome parts in the bender element test is near field effects, which affect the selection of arrival time. The selection of the first arrival within the near field Is effectively solved by the multiple reflection technique and signal matching technique. Bender elements, which requires several considerations, may be effective tools for the subsurface characterization by using S-wave.

Seismic response of nuclear containment structures due to recorded and simulated near-fault ground motions

  • Kurtulus Soyluk;Hamid Sadegh-Azar;Dersu Yilmaz
    • Structural Engineering and Mechanics
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    • v.87 no.5
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    • pp.431-450
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    • 2023
  • In this study, it is intended to perform nonlinear time-history analyses of nuclear power plant structures (NPP) under near-fault earthquakes showing directivity pulse and fling-step characteristics. Simulation procedures based on cycloidal pulse and far-fault ground motions are also used to simulate near-fault motions showing forward-directivity and fling-step characteristics and the structural responses are compared with those of the recorded near-fault ground motions. Because it is aimed to determine specifically the pulse type characteristics of near-fault ground motions on NPPs, all the ground motions are normalized to have a PGA of 0.3 g. Depending on the obtained results it can be underlined that although near-fault ground motion has the potential to cause damage mostly on structural systems having larger periods, it may also have noticeable effects on the responses of rigid structures, like NPP containment buildings. On the other hand, simulated near-fault motions can help us to get an insight into the near-fault mechanism as well as an approximate visualization of the structural responses under near-fault earthquakes.

The Influence of the Presence Perceived by Learners and Participation Motivation on Satisfaction in Distance Education (원격교육에서 성인학습자의 교육참여동기와 실재감이 학습만족도에 미치는 영향)

  • Lee, Jae-Eun;Yu, Byeong-Min;Park, Hye-Jin
    • Journal of Agricultural Extension & Community Development
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    • v.22 no.2
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    • pp.233-243
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    • 2015
  • This study is for understanding differences of satisfaction followed by learning and teaching presence perceived by learners and participation motivation on learning in a distance education. General characteristics of learner are classified as an entrance type, sex, age, new/transfer of distance university learners. Perceived presence is classified with learning presence and teaching presence. Participation motivation on learning is classified with the directivity of activity, goal, and study based on the reason of participating in classes in a distance university. And this research tried out to find the effects of learner's characteristics, perceived presence, and participation motivation on learning satisfaction. The results are as follows. First, there was no meaningful difference of general characteristic on satisfaction. It means sex, age, and entrance type did not have an effect on satisfaction. Second, with the level of presence perceived by learner, satisfaction has meaningful differences. It means that students who had higher learning presence perceived of distance university showed higher satisfaction, and so as in teaching presence perceived on satisfaction. Third, factors effecting satisfaction based on participation motivation on learning differ with types of motivation. There was no meaningful difference of the level of activity directivity study participant on satisfaction, but was a meaningful difference of goal directivity and of study directivity in participation motivation on learning satisfaction. It was the learning presence that had a significant effect on learning satisfaction of adult learning.