• Title/Summary/Keyword: IPE

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Seismic response of built-up double-I column in steel moment resisting frame using welded external diaphragm plate

  • Tabebordbar, Amir;Dehghan, Seyed Mehdi;Fathi, Farshid;Najafgholipour, Mohammad Amir
    • Steel and Composite Structures
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    • v.41 no.5
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    • pp.747-759
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    • 2021
  • Built-up Double-I (BD-I) columns have been commonly used for mid-rise steel-frame structures in Iran. These columns consist of two hot rolled IPE sections which are connected by two cover plates and fillet welds. Until 2017, BD-I columns were employed in intermediate moment resisting frames (MRF) using welded flange plate (WFP) connections. To evaluate the seismic behavior of the connections, four samples were made and tested based on cyclic loading according to AISC 341-16. It was concluded that typical samples cannot satisfy the seismic provisions related to intermediate MRFs. In contrast, the proposed connections retrofitted with two-part external diaphragms were able to satisfy not only the seismic requirements related to intermediate MRFs but also those related to special MRFs according to AISC. The numerical modeling of these samples was performed using ABAQUS finite element software. This study compared the hysteresis moment-rotation curves, plastic strains, and behavior modes in both experimental samples and numerical models.

A Study on the Band Structure of ZnO/CdS Heterojunction for CIGS Solar-Cell Application

  • Sim, Hana;Lee, Jeongmin;Cho, Seongjae;Cho, Eou-Sik;Kwon, Sang Jik
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.2
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    • pp.267-275
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    • 2015
  • In this paper, ZnO films were prepared by atomic layer deposition (ALD) and CdS films were deposited using chemical bath deposition (CBD) to form ZnO/CdS heterojunction. More accurate mapping of band arrangement of the ZnO/CdS heterojunction has been performed by analyzing its electrical and optical characteristics in depth by various methods including transmittance, x-ray photoemission spectroscopy (XPS), and ultraviolet photoemission spectroscopy (UPS). The optical bandgap energies ($E_g$) of ZnO and CdS were 3.27 eV and 2.34 eV, respectively. UPS was capable of extracting the ionization potential energies (IPEs) of the materials, which turned out to be 8.69 eV and 7.30 eV, respectively. The electron affinity (EA) values of ZnO and CdS calculated from IPE and $E_g$ were 5.42 eV and 4.96 eV, respectively. Energy-band structures of the heterojunction could be accurately drawn from these parameters taking the conduction band offset (CBO) into account, which will substantially help acquisition of the full band structures of the thin films in the CIGS solar-cell device and contribute to the optimal device designs.

Experimental investigation of force-distribution in high-strength bolts in extended end-plate connections

  • Abdalla, K.M.;Abu-Farsakh, G.A.R.;Barakat, S.A.
    • Steel and Composite Structures
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    • v.7 no.2
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    • pp.87-103
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    • 2007
  • This paper presents some of the results from an experimental research project on the behavior of extended end-plate connections subjected to moment conducted at the Structural Laboratory of Jordan University of Science and Technology. Since the connection behavior affects the structural frame response, it must be included in the global analysis and design. In this study, the behavior of six full-scale stiffened and unstiffened cantilever connections of HEA- and IPE-sections has been investigated. Eight high strength bolts were used to connect the extended end-plate to the column flange in each case. Strain gauges were installed inside each of the top six bolts in order to obtain experimentally the actual tension force induced within each bolt. Then the connection behavior is characterized by the tension force in the bolt, extended end-plate behavior, moment-rotation relation, and beam and column strains. Some or all of these characteristics are used by many Standards; therefore, it is essential to predict the global behavior of column-beam connections by their geometrical and mechanical properties. The experimental test results are compared with two theoretical (equal distribution and linear distribution) approaches in order to assess the capabilities and accuracy of the theoretical models. A simple model of the joint is established and the essential parameters to predict its strength and deformational behavior are determined. The equal distribution method reasonably determined the tension forces in the upper two bolts while the linear distribution method underestimated them. The deformation behavior of the tested connections was characterized by separation of the column-flange from the extended end-plate almost down to the level of the upper two bolts of the lower group and below this level the two parts remained in full contact. The neutral axis of the deformed joint is reasonably assumed to pass very close to the line joining the upper two bolts of the lower group. Smooth monotonic moment-rotation relations for the all tested frames were observed.

A Study on the Automatic Lexical Acquisition for Multi-lingustic Speech Recognition (다국어 음성 인식을 위한 자동 어휘모델의 생성에 대한 연구)

  • 지원우;윤춘덕;김우성;김석동
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.6
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    • pp.434-442
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    • 2003
  • Software internationalization, the process of making software easier to localize for specific languages, has deep implications when applied to speech technology, where the goal of the task lies in the very essence of the particular language. A greatdeal of work and fine-tuning has gone into language processing software based on ASCII or a single language, say English, thus making a port to different languages difficult. The inherent identity of a language manifests itself in its lexicon, where its character set, phoneme set, pronunciation rules are revealed. We propose a decomposition of the lexicon building process, into four discrete and sequential steps. For preprocessing to build a lexical model, we translate from specific language code to unicode. (step 1) Transliterating code points from Unicode. (step 2) Phonetically standardizing rules. (step 3) Implementing grapheme to phoneme rules. (step 4) Implementing phonological processes.

Seismic analysis of high-rise steel frame building considering irregularities in plan and elevation

  • Mohammadzadeh, Behzad;Kang, Junsuk
    • Steel and Composite Structures
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    • v.39 no.1
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    • pp.65-80
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    • 2021
  • Irregularities of a building in plan and elevation, which results in the change in stiffness on different floors highly affect the seismic performance and resistance of a structure. This study motivated to investigate the seismic responses of high-rise steel-frame buildings of twelve stories with various stiffness irregularities. The building has five spans of 3200 mm distance in both X- and Z-directions in the plan. The design package SAP2000 was adopted for the design of beams and columns and resulted in the profile IPE500 for the beams of all floors and box sections for columns. The column cross-section dimensions vary concerning the number of the story; one to three: 0.50×0.50×0.05m, four to seven: 0.45×0.45×0.05 m, and eight to twelve: 0.40×0.40×0.05 m. Real recorded ground accelerations obtained from the Vrancea earthquake in Romania together with dead and live loads corresponding to each story were considered for the applied load. The model was validated by comparing the results of the current method and literature considering a three-bay steel moment-resisting frame of eight-story height subject to seismic load. To investigate the seismic performance of the buildings, the time-history analysis was performed using ABAQUS. Deformed shapes corresponding to negative and positive peaks were provided followed by the story drifts and fragility curves which were used to examine the probability of collapse of the building. From the results, it was concluded that regular buildings provided a seismic performance much better than irregular buildings. Furthermore, it was observed that building with torsional irregularity was more vulnerable to seismic failure.

The Effectiveness of Team-based Case-based Learning Approach on the Learning Outcome: A Single Course Level in a University Setting

  • Hye Yeon Sin
    • Korean Journal of Clinical Pharmacy
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    • v.32 no.4
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    • pp.328-335
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    • 2022
  • Background: Case-based learning (CBL) is becoming an important approach for improving interprofessional collaboration education. Previous studies have examined learners' satisfaction with interprofessional education (IPE) in medical institutions. However, there are few studies on the implementation of university-led CBL interventions and their direct effects on learning outcomes. The aim of this study was to evaluate the effectiveness of CBL interventions on changes in the participants' perception and knowledge acquisition ability. Methods: The CBL approach consisted of team-based case-based learning, self-directed learning, and post-feedback. It was conducted as a single course for pharmacy students in their 5th year in a university setting. Changes in the participants' perceptions and self-assessments of competence levels were evaluated using survey responses. The effect of the CBL intervention on knowledge acquisition ability was directly evaluated using the exam score. Results: The majority agreed or strongly agreed that team-based case-based learning, and self-directed learning helped them to improve their knowledge and skills to a higher level and to increase the self-assessment of competency level. The average score of knowledge acquisition ability (average score of 75.0, p=0.0098) was significantly higher in the CBL intervention group than the lecture-based learning intervention group (average score of 52.0). Conclusion: The participants positively perceived that CBL intervention helped them to effectively improve their knowledge and the self-assessment of competency level. It also enhanced knowledge acquisition ability. These data, based on the survey responses, suggest that it is necessary to implement CBL interventions in a university-led single professional education.

A Study on the Influence Diagrams for the Application to Containment Performance Analysis (격납용기 성능해석을 위한 영향도에 관한 연구)

  • Park, Joon-Won;Jae, Moon-Sung;Chun, Moon-Hyun
    • Nuclear Engineering and Technology
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    • v.28 no.2
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    • pp.129-136
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    • 1996
  • Influence diagram method is applied to containment performance analysis of Young-Gwang 3&4 in an effort to overcome some drawbacks of current containment performance analysis method. Event tee methodology has been adopted as a containment performance analysis method. There are, however, some drawbacks on event tree methodology. This study is to overcome three major drawbacks of the current containment performance analysis method : 1) Event tree cannot express dependency between events explicitly. 2) Accident Progression Event Tree (APET) cannot represent entire containment system. 3) It is difficult to consider decision making problem. To resolve these problems, influence diagrams, is proposed. In the present ok, the applicability of the influence diagrams has been demonstrated for YGN 3&4 containment performance analysis and accident management strategy assessments of this study are in good agreement with those of YGN 3&4 IPE. Sensitivity analysis has been peformed to identify relative important variables for each early containment failure, late containment and basemat melt-though. In addition, influence diagrams are used to assess two accident management strategies : 1) RCS depressurization, 2) cavity flooding. It is shown that influence diagrams can be applied to the containment performance analysis.

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Comparison of nutritional characteristics between wild and cultured juvenile black rockfish, Sebastes schlegeli (자연산 및 양식산 조피볼락 치어의 영양학적 특성 비교)

  • LEE HaeYoung;PARK Min Woo;JRON Im Gi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.2
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    • pp.137-142
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    • 2000
  • Cultured juvenile black rockfish, Sebastes schiegeli as a seed for sen ranching project were compared with the similar size of wild fish. Wild fish were analyzed and compared with cultured fish in body indices, and moisture, crude protein, lipid, ash, many kinds of amino acids and various minerals in the whole-body of juvenile rockfish from three different populations. There were significant (P<0.05) differences in the moisture, crude lipid, and ash in the whole-body of fish among three different populations; the moisture content of wild fish was higher than that of both cultured fish. The lipid content in wild and tank cultured fish was lowest and highest, respectively; The lipid content of fish cultured in embanked system was intermediate values. The condition factor (CE), hepatosomatic index (HSI), and intraperitoneal fat (IPE) of fish cultured in tank system and embanked system were significantly (P<0.05) higher than those of wild fish. But fish cultured in tank system produced similar intestinosomatic index (ISI) and muscle ratio (MR) values as the wild fish. There were significant differences in asparatic acid, glutamic acid, isoleucine, leucine, lysine, phenylalanine, threonine, valine of whole-body fish cultured by different methods; the wild fish was highest in these amino acids, followed by fish cultured in embanked system and then fish cultured in tank system. There were also significant differences in Ca, P, Mg, Mn, Zn of whole-body fish cultured by different methods: wild fish and fish cultured in tank system produced highest in Ca, P, Mg, Zn and lowest in Mn, respectively. There were significant differences in moisture, crude lipid, ash, many kinds of amino acids, several minerals, CE, HSI, UE, and ISI among the three juvenile populations; whole-body of wild fish showed higher in moisture, ash, asparatic acid, glutamic acid, isoleucine, leucine, Iysine, phenylalanine, threonine, valine, Ca, P, Mg, and Zn than fish cultured in embanked system, while they showed lower in the rest of the nutritious parameters studied.

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