• Title/Summary/Keyword: introduction to engineering design

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Seismic performance of secondary systems housed in isolated and non-isolated building

  • Kumar, Pardeep;Petwal, Sandeep
    • Earthquakes and Structures
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    • v.16 no.4
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    • pp.401-413
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    • 2019
  • The concept of base isolation for equipment is well known. Its application in buildings and structures is rather challenging. Introduction of horizontal flexibility at the base helps in proper energy dissipation at the base level thus reducing the seismic demand of the super structure to be considered during design. The present study shows the results of a series of numerical simulation studies on seismic responses of secondary system (SS) housed in non-isolated and base-isolated primary structures (PS) including equipment-structure interactions. For this study the primary structure consists of two similar single bay three-store reinforced cement concrete (RCC) Frame building, one non-isolated with conventional foundation and another base isolated with Lead plug bearings (LPB) constructed at IIT Guwahati, while the secondary system is modeled as a steel frame. Time period of the base isolated building is higher than the fixed building. Due to the presence of isolator, Acceleration response is significantly reduced in both (X and Y) direction of Building. It have been found that when compared to fixed base building, the base isolated building gives better performance in high seismic prone areas.

Viewpoint Model Manipulating Inconsistencies Management

  • Ahmad Dalalah;Jalawi AlShudukhi
    • International Journal of Computer Science & Network Security
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    • v.23 no.2
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    • pp.96-100
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    • 2023
  • In this paper, each inconsistency management process activities was addressed. In addition, a guideline to deal with inconsistency by viewpoints method are introduced. At the end of the paper you should have clear idea to support inconsistency management in future research and having good knowledge of inconsistency management process activities and research issues. Moreover, it gives the researcher ability to design new framework by using powerful concept in inconsistency management and viewpoint techniques. The paper is organized as follows: an introduction is presented in section one, section two contains process viewpoint, while section three includes the proposed model and conclusions are in section four.

COMPARISON OF THREE PCM PERFORMANCE EVALUATION SYSTEMS IN TAIWAN

  • Wen-der Yu ;Yen-ping Hsu
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.719-724
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    • 2005
  • It has been debating on the performance evaluation of professional construction management (PCM) services since its introduction to Taiwan's construction industry more than a decade ago. Several evaluation systems were proposed by previous researchers. However, there has no comparison study been conducted for the feasibility, effectiveness, and appropriateness of these systems to the performance management (PM) of practical PCM services. This paper is intended for this end to compare the existing PCM performance evaluation systems in Taiwan. A real world design/build (D/B) building project was selected for case study. The result of case study concludes and compares the pro's and con's of the three systems. At the end, it recommends strategies for selecting the most appropriate PCM performance evaluation for PCM services.

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Compact Planar Antenna for Mobile Handset Applications

  • Sung, Woo Hee;Shin, Dong Gi;Lee, Young Soon
    • Journal of Advanced Information Technology and Convergence
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    • v.9 no.2
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    • pp.99-105
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    • 2019
  • In this paper, we describe the procedure of simulation design and measured results of a compact planar antenna for handset applications. The broad bandwidth covering the interested frequency band for mobile handset is achieved by introduction of an open ended L-shaped slot which is newly proposed and corresponds to the monopole slot. In order to minimize the impact on circuit part placement, the proposed antenna is placed on the ground plane edge of PCB with size of 60×65 mm2. The measurement result for 10dB impedance bandwidths is 640 MHz (1.7~2.34 GHz), covering the required bandwidths for DCS (Digital Cellular System)-1800 (1710 ~ 1880 MHz) / IMT (International Mobile Telecommunication)-2000 (1885 ~ 2200 MHz) bands. In particular, we would like to emphasize the proposed antenna has an omnidirectional radiation pattern suitable for commercial wireless communication.

On the Development of GUI and Command Based Finite Element Method Package in CEMTool (CEMTool 환경에서 GUI 및 명령어 기반 유한요소법 패키지 개발에 관하여)

  • Ahn, Choon-Ki;Park, Jeong-Hoon;Kwon, Wook-Hyun
    • Proceedings of the KIEE Conference
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    • 2004.07d
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    • pp.2568-2570
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    • 2004
  • CEMTool is a command style design and analyzing package for scientific and technological algorithm and a matrix based computation language. In this paper, we present new FEM (Finite Element Method) package in CEMTool environment. In contrast to the existing MATLAB PDE Toolbox, our proposed FEM package can deal with the combination of the reserved words. Also, we can control the mesh in a very effective way With the introduction of new mesh generation algorithm and NDM (Hosted Dissection Method), our FEM package can guarantee the shorter computational time than MATLAB PDE Toolbox. In addition, using the advanced electromagnetics library of CEMTool FEM package, we can analyze the practical problems such as the motor field analysis. Consequently, with our new FEM package, we can overcome some disadvantages of the existing MATLAB PDE Toolbox.

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Enhancing Thermal Conductivity in Epoxy Composites with Functionalized Boron Nitride Nanosheets

  • Yang Soo Kim;Ik-Tae Im;Jong Seok Kim
    • Korean Journal of Materials Research
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    • v.33 no.12
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    • pp.503-510
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    • 2023
  • This comprehensive study delves into the intricate process of exfoliating and functionalizing boron nitride nanosheets (BNNSs) extracted from hexagonal boron nitride (h-BN), and meticulously explores their potential application within epoxy composites. The extensive research methodology encompasses a sequence of treatments involving hydrothermal and sonication processes aimed at augmenting the dispersion of BNNSs in solvents. Leveraging advanced analytical techniques such as Raman spectroscopy, X-ray diffraction, and FTIR spectroscopy, the study rigorously analyzes a spectrum of changes in the BNNS's properties, including layer count variations, interlayer interactions, crystal structure modifications, and the introduction of functional groups. The research also rigorously evaluates the impact of integrating BNNSs, specifically glycidyl methacrylate (GMA)-functionalized BNNSs, on the thermal conductivity of epoxy composites. The conclusive findings exhibit notable enhancements in thermal properties, predominantly attributed to the enhanced dispersion of fillers and enhanced interactions within the epoxy matrix. This pioneering work illuminates the wide potential of functionalized BNNSs for significantly enhancing the thermal conductivity of epoxy composites, paving the way for advanced materials engineering and practical applications.

Surface Treatment and Dyeability of Poly(phenylene sulfide) Films by UV/O3 Irradiation (UV/Ozone 조사에 의한 Poly(phenylene sulfide) 필름의 표면처리와 염색성)

  • Jang, Yong-Joon;Jang, Jin-Ho
    • Textile Coloration and Finishing
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    • v.23 no.4
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    • pp.284-289
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    • 2011
  • Poly(phenylene sulfide)(PPS) films were photooxidized under UV/ozone irradiation. The effect of UV energy on the surface properties of the UV-irradiation PPS films were investigated by the measurement of reflectance, surface roughness, and contact angle. Reflectance decreased at the wavelength of 400nm and the surface roughness increased with increased UV energy. The improvement in hydrophilicity with increased $O_{1s}/C_{1s}$ was caused by the introduction of hydrophilic $SO_2$ bond. Surface energy increased from 46.6 to $78.3mJ/m^2$ with increased UV energy up to $21.2J/cm^2$. Also zeta potential decreased with increased UV energy. The increased dyeability to cationic dyes may be due to the photochemically introduced anionic and dipolar dyeing sites on the PPS films surfaces.he photochemically introduced anionic and dipolar dyeing sites on the PPS films surfaces.

Photooxidation of Poly(vinyl butyral) Films by UV/Ozone Irradiation (자외선/오존 조사에 의한 Poly(vinyl butyral)의 광산화)

  • Joo, Jin-Woo;Jang, Jinho
    • Textile Coloration and Finishing
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    • v.27 no.2
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    • pp.113-118
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    • 2015
  • Poly(vinyl butyral), PVB was photooxidized by UV/ozone irradiation and the effect of UV energy on the surface properties of the UV-irradiated PVB film were investigated by the measurement of reflectance, surface roughness, contact angles, elemental composition, and zeta potential. With increasing UV energy, reflectance decreased in the visible and ultraviolet regions particularly at the wavelength of 400nm. The irradiation produced nano-scale surface roughness including the maximum peak-to-valley roughness increased from 274nm for the unirradiated PVB to 370nm at the UV energy of $5.3J/cm^2$. The improved hydrophilicity was due to the higher $O_{1s}/C_{1s}$ resulting from the introduction of polar groups such as C=O bonds. The surface energy of the PVB film increased from $35.3mJ/m^2$ to $39.3mJ/m^2$ at the irradiation of $15.9J/cm^2$. While the zeta potentials decreased proportionally with increasing UV energy, the cationic dyeability of the PVB increased accordingly resulting from the improved affinity of the irradiated PVB surfaces containing the photochemically introduced anionic and dipolar dyeing sites.

Photooxidation of Poly(butylene succinate) Films by UV/Ozone Irradiation (자외선/오존 조사에 의한 Poly(butylene succinate) 필름의 광산화)

  • Joo, Jin-Woo;Jang, Jinho
    • Textile Coloration and Finishing
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    • v.26 no.3
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    • pp.159-164
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    • 2014
  • Biodegradable Poly(butylene succinate), PBS, was photooxidized by UV/ozone irradiation and the effect of UV energy on the surface properties of the UV-irradiated PBS film were investigated by the measurement of reflectance, surface roughness, contact angles, chemical composition, and zeta potential. With increasing UV energy, reflectance decreased in the visible and ultraviolet regions particularly at the wavelength of 380nm. The irradiation produced nano-scale surface roughness including the maximum peak-to-valley roughness increased from 106nm for the unirradiated sample to 221nm at the UV energy of $10.6J/cm^2$. The improved hydrophilicity was due to the higher $O_{1s}/C_{1s}$ resulting from the introduction of polar groups such as C-O and C=O bonds. The surface energy of the PBS increased from $42.1mJ/m^2$ for the unirradiated PBS to $56.8mJ/m^2$ at the irradiation of $21.2J/cm^2$. The zeta potentials of the UV-irradiated PBS also decreased proportionally with increasing UV energy. The cationic dyeability of the PBS increased accordingly resulting from the improved affinity of the irradiated PBS surfaces containing photochemically introduced anionic and dipolar dyeing sites.

Analysis of Air Flow Rate Distribution for the Bathroom Exhaust System in High-rise Buildings Using T-method (T-method를 이용한 고층 아파트 욕실 배기 시스템의 층별 유량분배 해석)

  • 문종선;강석윤;이승철;유호선;이재헌
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.3
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    • pp.265-272
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    • 2004
  • Based on the T-method, a new scheme for predicting air flow rate distribution in a bathroom exhaust system is developed. Introduction of individual duct route enables us to disintegrate a complicated multi-fan ductwork into a set of simultaneous single-fan subsystems. The scheme is validated via the analysis of a well-posed test problem, showing physical consistency. In order to demonstrate the utility and capability of our method, the bathroom ventilation system in a 20-story residential building is selected as an example. Under the typical design condition, the air flow rate of each exhaust fan at the balancing point is successfully predicted, and such information can lead to an engineering estimation for the overall system performance. While some deficiencies in ventilation are found at bathrooms at lower floors with 6mmAq-rated exhaust fans, they disappear over the whole building by using fans of enhanced static pressures, 7 and 8mmAq. Finally the present scheme seems to be useful for practical design of multi-branched, multi-fan ventilation systems.