• Title/Summary/Keyword: KCI(2012)

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Crack Control in Beams and One-Way Slabs (보 및 1방향 슬래브의 균열제어)

  • Min, Chang-Shik
    • Journal of the Korea Concrete Institute
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    • v.24 no.4
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    • pp.381-390
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    • 2012
  • The KCI Building Code (2003 and 2007) provisions to control flexural cracking in beams and one-way slabs are discussed for related researches and the development of the provisions. Based on the basic ideas over the development of current provisions, possible problems with cracking control are identified and discussed for the remedies to fix the problems. Simple and clear equations to control flexural cracking in beams and one-way slabs are presented. The presented equations would avoid any conflicts with other provisions for the spacing of reinforcement.

Time Series Analysis of Intellectual Structure and Research Trend Changes in the Field of Library and Information Science: 2003 to 2017 (문헌정보학 분야의 지적구조 및 연구 동향 변화에 대한 시계열 분석: 2003년부터 2017년까지)

  • Choi, Hyung Wook;Choi, Ye-Jin;Nam, So-Yeon
    • Journal of the Korean Society for information Management
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    • v.35 no.2
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    • pp.89-114
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    • 2018
  • Research on changes in research trends in academic disciplines is a method that enables observation of not only the detailed research subject and structure of the field but also the state of change in the flow of time. Therefore, in this study, in order to observe the changes of research trend in library and information science field in Korea, co-word analysis was conducted with Korean author keywords from three types of journals which were listed in the Korea Citation Index(KCI) and have top citation impact factor were selected. For the time series analysis, the 15-year research period was accumulated in 5-years units, and divided into 2003~2007, 2003~2012, and 2003~2017. The keywords which limited to the frequency of appearance 10 or more, respectively, were analyzed and visualized. As a result of the analysis, during the period from 2003 to 2007, the intellectual structure composed with 25 keywords and 8 areas was confirmed, and during the period from 2003 to 2012, the structure composed by 3 areas 17 sub-areas with 76 keywords was confirmed. Also, the intellectual structure during the period from 2003 to 2017 was crowded into 6 areas 32 consisting of a total of 132 keywords. As a result of comprehensive period analysis, in the field of library and information science in Korea, over the past 15 years, new keywords have been added for each period, and detailed topics have also been subdivided and gradually segmented and expanded.

Design Evaluation of the Post-installed Anchor considering Effective Embedded Depth and Concrete Strength (유효 묻힘 깊이와 콘크리트 강도를 고려한 후설치 앵커의 설계식 평가)

  • Hur, Moo-Won;Chae, Kyoung-Hun;Won, Jae-Sik;Park, Tae-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.3
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    • pp.13-20
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    • 2021
  • Post-installed anchor is a structural material that connects structural and non-structural members to existing concrete members. However, there are cases where rebar interception and construction error occur at the site. In that case, measures are needed to prevent performance degradation of the rear-installation anchors. In this study, in order to evaluate the performance of torsional control expandable post-installed anchors for compressive strength and effective depth of the reference concrete was tested. The results of the most commonly used tests of M10 and M20 showed that had variable coefficients within 15%, satisfying the reliability presented in KCI(2017). It was also confirmed that the depth of the buried and the strength of concrete affect the strength of the pavement. Based on the results of the existing similar studies and the results of this study, the design equation of the post-installed anchor was proposed and the results were compared with the existing design.

A Study on the Structural Safety of Photovoltaic System Mounted on Balcony Railing (발코니 거치 태양광 발전장치의 구조적 안전성에 관한 연구)

  • Jo, Jeong-Jae;Chung, Yu-Gun
    • KIEAE Journal
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    • v.12 no.2
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    • pp.33-38
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    • 2012
  • This study aims to evaluate the structural safety of the balcony photovoltaic systems easily installed or moved on the buildings. Also, the systems are controlled by solar altitudes focused on its mobility rather than high efficiency generation performance thereof. The results of the study are as follows. Two types of typical photovoltaic systems which can be mounted on the balcony are proposed, and, the sizes of the systems are designed to be adjusted within certain ranges of the frames in order to attach the various rail sizes. To evaluate the structural safety of the proposed systems, several simulation evaluations are performed on the safety evaluation standards by the Ministry of Construction-Transportation and KCI 2007. The results are that the proposed plans are reasonable in terms of stress and deflection in the structural aspects at the wind pressures of $1,907(N/m^2)$ of external wall surface under the condition of wind velocity higher than 25(m/s).

Shear-Strengthening of Reinforced & Prestressed Concrete Beams Using FRP: Part I - Review of Previous Research

  • Ary, Moustapha Ibrahim;Kang, Thomas H.K.
    • International Journal of Concrete Structures and Materials
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    • v.6 no.1
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    • pp.41-47
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    • 2012
  • Fiber-Reinforced Polymers (FRP) are used to enhance the behavior of structural components in either shear or flexure. The research conducted in this paper was mainly focused on the shear-strengthening of reinforced and prestressed concrete beams using FRP. The main objective of the research was to identify the parameters affecting the shear capacity provided by FRP and evaluate the accuracy of analytical models. A review of prior experimental data showed that the available analytical models used to estimate the added shear capacity of FRP struggle to provide a unified design equation that can predict accurately the shear contribution of externally applied FRP. In this study, the ACI 440.2R-$08^1$ model and the model developed by Triantafillou and Antonopoulos$^2$ were compared with the prior experimental data. Both analytical models failed to provide a satisfactory prediction of the FRP shear capacity. This study provides insights into potential reasons for the unsatisfactory prediction.

An Experimental Study on the Evaluation of Shear Performance of PVA Fiber Reinforced RC Deep Beam with High Strength Headed Rebar

  • Kim, Seunghun;Lee, Kyuseon;Lee, Yongtaeg
    • Architectural research
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    • v.19 no.4
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    • pp.109-115
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    • 2017
  • This study is done to evaluate how existence of shear-span ratio and shear reinforcing bar effects on shear performance from through shear experiment using PVA fiber reinforced ferroconcrete building. Ratio of shear-span was set 1, 1.7, and arrangement of shear reinforcing bar was set with KCI2012 regulation. In result, subject with less shear-span ratio, and shear reinforcing bar with arrangement of bar shows high stiffness. Subjects with high shear-span ratio show large difference depending on existence of shear reinforcing bar. Therefore, theoretical shear strength followed by CEB code underestimates experimental shear strength by 43.9%. Shear strength of the deep beam with headed bars is more affected by the bearing strength of head than the bond strength of bar.

Analysis of Research Papers Published in the Korean Journal of Clinical Laboratory Science from 1985 to 2012

  • Koo, Bon Kyung
    • Korean Journal of Clinical Laboratory Science
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    • v.45 no.4
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    • pp.180-187
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    • 2013
  • The author surveyed and analyzed the research papers of korean journal of clinical laboratory science (KJCLS) that have been posted for 28 years from 17 volumes in 1985 to 44 volumes in 2012 in the time of 50th anniversary of foundation of the korean association of medical technologists (KAMT) of in 2012. This study is aimed to provide members with basic materials helpful to research development and suggest development measures of journal. The author analyzed the number of papers, research field, type of papers, and number of authors based on the title of paper. The total number of papers is 916 and average number of paper is 33. The research field was biochemistry 167 (18.2%), microbiology 160 (17.4%), histology & cytology 99 (10.8%), molecular genetics 77 (8.5%), hematology 69 (7.5%), physiologic function 64 (7.0%), immunology 60 (6.5%), blood bank 33 (3.6%), radioimmunoassay 33 (3.6%), parasitology 27 (2.9%), quality control 18 (2.0%), urinalysis & body fluid 13 (1.4%), cytogenetics 12 (1.3%), flow cytometry analysis 6 (0.7%), and other articles were 78 (8.5%). Regarding the type of papers, original article was 777 (84.8%), case report 52 (5.7%), review 23 (2.5%), others 64 (7.0%). Regarding the number of paper authors, single author was 208 (22.7%), 2-man joint authors 178 (19.4%), 3-man joint authors 181 (19.8%), 4-man joint authors 151 (16.5%), over-5-man joint authors 198 (21.6%). The average number of papers was 33 for 28 years from 1985 to 2012, it is fewer than number of technologists and professors working currently regardless of the level of quantity and quality. The KAMT needs paper promoting measures and strategic investment on the scholarly journals that can aggressively promote to members and inspire research desire for korea citation index (KCI) registered article selection of KJCLS in the future.

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An Introductory Review for the Conceptualization of Elementary Teachers' Science PCK: Synthesized Perspective of the Teacher Professional Knowledge and Skills Model (Consensus Model) and the Revised Consensus Model (초등교사의 과학 PCK 개념화를 위한 시론(試論)적 고찰 - 교사의 전문지식과 기능 모델(합의 모델) 및 수정된 합의 모델의 복합적 관점 -)

  • Maeng, Seungho
    • Journal of Korean Elementary Science Education
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    • v.43 no.1
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    • pp.201-217
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    • 2024
  • This introductory review study sought to conceptualize elementary school teachers' pedagogical content knowledge in science teaching (science PCK) by reinterpreting 11 science PCK research papers published in the Korean Journal Database from 2012 to 2023 based on the synthesized perspective of the model of teacher professional knowledge and skill (Consensus Model) proposed at the first PCK Summit in 2012 and the Revised Consensus Model (RCM) proposed at the second PCK Summit in 2016. Elementary teachers' science PCK was mainly analyzed based on Magnusson et al.'s (1999) PCK elements and described as the form of enacted PCK or personal PCK at the subject or discipline level. Personal PCK studies, which involved emotional factors, included the features of collective PCK from the RCM perspective. It was inferred that elementary school teachers' science PCK needs to be conceptualized by comprehensively considering the enacted PCK through individual teacher experiences and the collective PCK and personal PCK defined by experts.

Flexural Behavior of High-Strength Reinforced Concrete Beam with Recycled Aggregate Strengthened by FRP Plate (FRP로 보강된 순환골재 고강도 철근콘크리트 보의 휨거동)

  • Hong, Seong-Uk;Lee, Seung-Ho;Kim, Seung-Hun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.4
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    • pp.126-132
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    • 2018
  • As means to increase the use of concrete with recycled coarse aggregate (RCA), this study aims to evaluate the applicability for flexural strengthening of reinforced concrete beam with high-strength concretes and RCA on which FRP plates, used for repair and strengthening of old and low-durability reinforced concrete structures, is applied. In order to increase the adhesive force of epoxy and FRP plate, FRP plate was installed according to Near-Surface-Mounted (NSM) method. 12 specimens were manufactured using substitution rate of RCA (30%), concrete strengths (40MPa, 60MPa), diameters of deformed bar (D10, D13), and types of FRP plate (AFRP, CFRP) as variables to analyse flexural performance according to FRP plate and substitution rate of recycled aggregate. As a result, in all specimens, specimens strengthened by FRP plate showed a maximum of 17% increase in performance compared to specimens without FRP plate and strengthening performance of CFRP was found to be higher than AFRP. When modulus of rupture was used, the value of cracking moment was similar to that of the reference equation. As bending moment of some specimens strengthened by FRP plate failed to satisfy the criteria of KCI 2012 and ACI 440-2R, additional experiment is deemed as necessary.

Evaluation of Structural Behavior and Moment of Inertia on Modular Slabs Subjected to Cyclic Loading (반복하중을 받는 모듈러 슬래브의 거동 및 단면2차모멘트 평가)

  • Park, Jongho;Choi, Jinwoong;Lee, Hong-Myung;Park, Sun-Kyu;Hong, Sungnam
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.6
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    • pp.95-102
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    • 2015
  • Recently, the maintenance activity for aging of bridge structures was difficult because of traffic jam, environment pollution and increasing cost. And to solve these problems, modular bridge research has been studied. After static and cyclic loading test was conducted for serviceability and bending performance with one way slab, effective moment of inertia of modular specimen was analyzed to estimate the deflection by KCI(2012). To conduct the test, one integral slab and three modular slabs were made for static loading and one integral and modular slab were made for cyclic. As a result of the test, the modular slab had the similar bending performance of the integral. But the ultimate deflection showed the insufficient which was smaller than 20%. In the cyclic loading test, the modular slab has different behavior of deflection with the integral, so it was evaluated difficult for serviceability. In addition, effective moment of inertia by KCI(2012) was not estimated for modular slab with connection. The new value of m which was ratio between moments is 4.53 based on result of test for predicting deflection of modular.