• 제목/요약/키워드: model concrete

Search Result 5,283, Processing Time 0.031 seconds

A Bike Mode Share Estimation Model and Analysis of the Bike Demand Factor Effects (자전거 수단분담률 추정모형 구축 및 자전거 수요요인분석)

  • Lee, Gyu-Jin;Choe, Gi-Ju
    • Journal of Korean Society of Transportation
    • /
    • v.28 no.3
    • /
    • pp.145-155
    • /
    • 2010
  • As the green transportation mode, revitalization of bike usage attracts remarkable public attention. For the acquirement of effective outcome, however, the concrete and close analysis about bike utilization characteristics should be arranged first. One result by MLTM(2009) is support this opinion; the bike mode share has been decreased whereas 9,170km of the bicycle path was improved(1995~2007). This study analyzed the bike mode share classified by trip types by using the 303,308 data of Household Travel Survey of Seoul Metropolitan Area, 2006. The highest mode share rate was induced by the institute attendee and Officetel resident as 3.75% and 3.13%, respectively. Also this study established the bike mode share estimation model of Seoul by logistic regression, and analyzed related factors and level of effectiveness related bike demand by calculation of odds ratio in terms of logistic regression coefficients. In conclusion, short trips, institutes district, parks, and Officetel residential area oriented policy should be effective on the revitalization of bike usage.

A Study on the Acceptance of Information Literacy Instruction for School Libraries in Korea (학교도서관 중심의 정보활용능력 교육 수용에 관한 연구)

  • Kim Yeon-Rye;Hong Hyun-Jin
    • Journal of Korean Library and Information Science Society
    • /
    • v.37 no.3
    • /
    • pp.3-32
    • /
    • 2006
  • This paper examined the information literacy which is the concrete purpose of the ICT using education which appeared in order to elevate the effects of education in school after the introduction of the 7th educational curriculum. Based on TAM (Technology Acceptance Model) that provides useful theoretical foundations for analyzing the factors influencing acceptance and diffusion of IT, it determined the factors influencing the process of accepting the information literacy instruction as follows: perceived usefulness; perceived ease of use; attitude; effects of the information literacy instruction; teachers' innovation; school library relevance; school librarians' support; and the self-efficacy. This paper confirmed the influences of these factors on the process of accepting the information literacy through empirical study. Through this study, it intended to suggest the ways to activate of the information literacy instruction.

  • PDF

Small scale computational vibration of double-walled CNTs: Estimation of nonlocal shell model

  • Asghar, Sehar;Khadimallah, Mohamed Amine;Naeem, Muhammad N.;Ghamkhar, Madiha;Khedher, Khaled Mohamed;Hussain, Muzamal;Bouzgarrou, Souhail Mohamed;Ali, Zainab;Iqbal, Zafar;Mahmoud, S.R.;Algarni, Ali;Taj, Muhammad;Tounsi, Abdelouahed
    • Advances in concrete construction
    • /
    • v.10 no.4
    • /
    • pp.345-355
    • /
    • 2020
  • In this paper, vibration characteristics of double-walled carbon nanotubes (CNTs) is studied based upon nonlocal elastic shell theory. The significance of small scale is being perceived by developing nonlocal Love shell model. The wave propagation approach has been utilized to frame the governing equations as eigen value system. The influence of nonlocal parameter subjected to diverse end supports has been overtly analyzed. An appropriate selection of material properties and nonlocal parameter has been considered. The influence of changing mechanical parameter Poisson's ratio has been investigated in detail. The dominance of boundary conditions via nonlocal parameter is shown graphically. The results generated furnish the evidence regarding applicability of nonlocal shell model and also verified by earlier published literature.

Analysis on Library-Aided Instruction's Obstacle Factors based on Human Performance Technology Model (인간수행공학을 적용한 도서관활용수업의 저해요인 분석 연구)

  • Jung, Jong-Kee
    • Journal of Korean Library and Information Science Society
    • /
    • v.40 no.1
    • /
    • pp.433-449
    • /
    • 2009
  • The purpose of this study is to find out the factors which have interrupted Library Assisted Instruction in various schools' libraries and to analyze the factors by the tools and to propose the solutions to the obstacles for the desired Library Assisted Instruction. For doing this, some experimental processes had been made: firstly, to make the analysis model based on HPT for the improvement of the real LAI, secondly, to apply the model to LAI, to draw out the problems and to analyze them, and to propose the solutions. As the results of this study, the 5 solutions are presented; 1) LAIs should have the obvious and concrete teaching&learning objectives. 2) The supporting systems for LAI like the web community ought to be prepared. 3) External motivation systems, that is, teachers and teacher-librarians' performance assessment with LAI participation rate per year, should be developed. 4) The various, practical LAI programs should be developed. 5) The obscure refusal of teachers & teacher-librarians to LAI should be disappeared and the directors of schools should be confident of the LAI's educational, positive effects.

  • PDF

Shaking table test of wooden building models for structural identification

  • Altunisik, Ahmet C.
    • Earthquakes and Structures
    • /
    • v.12 no.1
    • /
    • pp.67-77
    • /
    • 2017
  • In this paper, it is aimed to present a comparative study about the structural behavior of tall buildings consisting of different type of materials such as concrete, steel or timber using finite element analyses and experimental measurements on shaking table. For this purpose, two 1/60 scaled 28 and 30-stories wooden building models with $40{\times}40cm$ and $35{\times}35cm$ ground/floor area and 1.45 m-1.55 m total height are built in laboratory condition. Considering the frequency range, mode shapes, maximum displacements and relative story drifts for structural models as well as acceleration, displacement and weight limits for shaking table, to obtain the typical building response as soon as possible, balsa is selected as a material property, and additional masses are bonded to some floors. Finite element models of the building models are constituted in SAP2000 program. According to the main purposes of earthquake resistant design, three different earthquake records are used to simulate the weak, medium and strong ground motions. The displacement and acceleration time-histories are obtained for all earthquake records at the top of building models. To validate the numerical results, shaking table tests are performed. The selected earthquake records are applied to first mode (lateral) direction, and the responses are recorded by sensitive accelerometers. Comparisons between the numerical and experimental results show that shaking table tests are enough to identify the structural response of wooden buildings. Considering 20%, 10% and 5% damping rations, differences are obtained within the range 4.03-26.16%, 3.91-65.51% and 6.31-66.49% for acceleration, velocity and displacements in Model-1, respectively. Also, these differences are obtained as 0.49-31.15%, 6.03-6.66% and 16.97-66.41% for Model-2, respectively. It is thought that these differences are caused by anisotropic structural characteristic of the material due to changes in directions parallel and perpendicular to fibers, and should be minimized using the model updating procedure.

Seismic Fragility Analysis of High-Rise RC Box-Type Wall Building Structures (고층 RC 벽식 건물의 지진 취약도 분석)

  • Jeong, Gi Hyun;Lee, Han Seon;Hwang, Kyung Ran;Kwon, Oh-Sung;Kim, Sung-Jig
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.20 no.3
    • /
    • pp.155-162
    • /
    • 2016
  • Observations of the damages to high-rise reinforced concrete (RC) wall building structures caused by by recent earthquakes in Chile ($M_w$ 8.8, February 2010) and New Zealand (February 2011, $M_L$ 6.3) have generally exceeded expectations. Firstly, this study estimated the seismic damage levels of 15-story RC box-type wall building structures using the analytical models calibrated by the results of a shaking table test on a 1:5 scale 10-story RC box-type wall building model. Then, the seismic fragility analysis of the prototype model was conducted by using the SAC/FEMA method and the incremental dynamic analysis (IDA). To compensate for the uncertainties and variability of ground motion and its impacts on the prototype model, in the SAC/FEMA method, a total of 61 ground motion records were selected from 20 earthquakes, with a magnitude ranging from 5.9 to 8.8 and an epicentral distance ranging from 5 to 105km. In the IDA, a total of 11 ground motion records were used based on the uniform hazard response spectrum representing a return period of 2,475 years. As a result, the probabilities that the limits of the serviceability, damage control, and collapse prevention would be exceeded were as follows: from the SAC/FEMA method: 79%, 0.3%, and 0%, respectively; and from the IDA: 57%, 1.7%, and 0%, respectively.

Design and Development of WBI Contents: A Goal-based Scenarios (GBS) Model Approach (Goal-based Scenarios(GBS) 모형을 적용한 웹기반 교육용 컨텐츠의 설계 및 개발 연구)

  • Cho, Kyoo-Lak;Cho, Young-hoan;Kim, Meekyoung;Sung, Bongsik
    • The Journal of Korean Association of Computer Education
    • /
    • v.7 no.5
    • /
    • pp.9-21
    • /
    • 2004
  • In spite of the strong request that Internet, a new IT technique, should be extensively used in classroom settings, WBI is not still wide spread. One possible reason is that most WBIs developed so far are not qualitatively different from the traditional classroom ones and various design models for WBI are unknown. Developing a WBI program according to Goal-based Scenarios (GBS), a constructivistic instructional design model, this study offers a useful case for the design and development of WBI to educators and implementers. The program developed embodied seven important components of the GBS model. The development process also included needs assessment, task analysis, and learner and environment analysis, which are the basic components of the domain of instructional design. The GBS development case in this article will provide concrete guidelines to educational practitioners who have an intention to create a new type of WBI in schools as well as in corporate.

  • PDF

Fuzzy Colored Timed Petri Nets for Context Inference (상황 추론을 위한 Fuzzy Colored Timed Petri Net)

  • Lee Keon-Myung;Lee Kyung-Mi;Hwang Kyung-Soon
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.16 no.3
    • /
    • pp.291-296
    • /
    • 2006
  • In context-aware computing environment, some context is characterized by a single event, but many other contexts are determined by a sequence of events which happen with some timing constraints. Therefore context inference could be conducted by monitoring the sequence of event occurrence along with checking their conformance with timing constraints. Some context could be described with fuzzy concepts instead of concrete concepts. Multiple entities may interact with a service system in the context-aware environments, and thus the context inference mechanism should be equipped to handle multiple entities in the same situation. This paper proposes a context inference model which is based on the so-called fuzzy colored timed Petri net. The model represents and handles the sequential occurrence of some events along with involving timing constraints, deals with the multiple entities using the colored Petri net model, and employs the concept of fuzzy tokens to manage the fuzzy concepts.

Linear Algebra Teaching in the Digital Age (디지털 시대의 대학수학교육: 선형대수학을 중심으로)

  • Lee, Sang-Gu;Lee, Jae Hwa;Park, Kyung-Eun
    • Communications of Mathematical Education
    • /
    • v.31 no.4
    • /
    • pp.367-387
    • /
    • 2017
  • The educational environment in the digital age of the 21st century definitely affects teaching and learning methods to be changed. In addition, the perceptions and methods of mathematics education in the digital age have also been changing. This study proposes a university mathematics education model suitable for the digital age, which makes full use of the internet/digital environment and leads the students to participate in the learning processes. We apply the proposed model to Linear Algebra course, and present a concrete method of teaching and learning model including evaluation. This will be the first study on how to organize and operate digital courses in Korea in accordance with the mathematics education in the digital era which is rapidly spreading around the world.

Dynamic Characteristic of Truss Type Lift Gate by Model Tests (모형실험에 의한 트러스형 리프트 게이트의 진동 특성)

  • Lee, Seong Haeng;Shin, Dong Wook;Kim, Kyoung Nam;Jung, Kyoung Sup
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.32 no.6A
    • /
    • pp.337-345
    • /
    • 2012
  • A model test is performed to investigate the dynamic behavior of truss type lift gate which is being constructed by the four major rivers project. The gate dimensioned 40 m in width, 9m in height is scaled with the ratio of 1:25 and is made of acryl panel and supplemented weight by lead in the concrete test flume dimensioned 1.2 m in width, 0.5 m in height and 30m in length. Firstly natural frequencies of the model gate are measured and compared with the numerical results for the calibration. The amplitudes of the vibration are measured under the different gate opening, upstream water level conditions. Also models with bottom angle $20^{\circ}$, $35^{\circ}$ and $50^{\circ}$ are tested and compared to find out a proper shape of bottom structure which minimizes the gate vibration. These test results presents a basic data for the guide manuals of gate management and a design method to reduce the gate vibration of truss type lift gate.