• Title/Summary/Keyword: structure engineering

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Application of Area-Saving RF Test Structure on Mobility Extraction

  • Lee, Jae-Hong;Kim, Jun-Soo;Park, Byung-Gook;Lee, Jong-Duk;Shin, Hyung-Cheol
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.9 no.2
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    • pp.98-103
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    • 2009
  • An RF test structure is proposed and its applicability is confirmed by measuring DC characteristics and high frequency characteristics. Effective mobility extraction is also performed to confirm the validity of proposed test structure. The area of suggested test structure consumed on wafer was decreased by more than 50% and its characteristics do not be degraded compared with conventional structure.

Feasibility study of bonding state detection of explosive composite structure based on nonlinear output frequency response functions

  • Si, Yue;Zhang, Zhou-Suo;Wang, Hong-fang;Yuan, Fei-Chen
    • Steel and Composite Structures
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    • v.24 no.4
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    • pp.391-397
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    • 2017
  • With the increasing application of explosive composite structure in many engineering fields, its interface bonding state detection is more and more significant to avoid catastrophic accidents. However, this task still faces challenges due to the complexity of the bonding interface. In this paper, the concept of nonlinear output frequency response functions (NOFRFs) is introduced to detect the bonding state of explosive composite structure. The NOFRFs can describe the nonlinear characteristics of nonlinear vibrating system. Because of the presence of the bonding interface, explosive composite structure itself is a nonlinear system; when bonding interface of the structure is damaged, its dynamic characteristics show enhanced nonlinear characteristic. Therefore, the NOFRFs-based detection index is proposed as indicator to detect the bonding state of explosive composite pipes. The experimental results verify the effectiveness of the detection approach.

New PDP cell structure for high luminous efficacy with low voltage driving

  • Jung, Hae-Yoon;Kim, Tae-Jun;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.480-484
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    • 2006
  • We propose a new PDP cell structure named DIDE (Dual Ignition Discharge Electrodes) structure with a long electrode gap to realize a high luminous efficacy. Suggested DIDE structure basically has a long electrode gap $(200{\mu}m{\sim}400{\mu}m)$, nevertheless, because of auxiliary electrodes formed on the front panel, can be driven at relatively low voltage. The discharge characteristic of DIDE structure was much different from that of conventional structure, which was analyzed by IR emission images using IICCD (Image Intensified Charge Coupled Device). The study can explain some particular characteristics of DIDE structure. As a result, the long electrode gap and low voltage effect can be expected in DIDE structure, and a very high luminous efficacy of 7.5 lm/W has been achieved in monochrome green test panel adopting the new cell structure with Ne-Xe (12%) mixture at 400 torr.

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Design Optimization of an Extruded-type Cooling Structure for Reducing the Weight of LED Streetlights (LED 가로등용 압출형 방열 구조물 경량화를 위한 최적 설계)

  • Park, Seung-Jae;Lee, Tae-Hee;Lee, Kwan-Soo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.28 no.10
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    • pp.394-401
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    • 2016
  • The configuration of an extruded-type cooling structure was optimized for the light-emitting diode (LED) streetlights that have recently replaced convectional metal halide streetlights for energy saving. Natural convection and radiative heat transfer over the cooling structure were simulated using a numerical model with experimental verification. An improved cooling structure type was suggested to overcome the previous performance degeneration, as confirmed by analyzing the thermal flow around the existing cooling structure. A parameter study of the cooling structure geometries was also conducted and, based on the numerical results, the configuration was optimized to reduce the weight of the cooling structure. Consequently, the mass of the cooling structure was reduced by 60%, while the thermal performance was improved by 10%.

Performance Analysis of GNSS Navigation Messages in the Structure Viewpoint

  • Noh, Jae Hee;Jo, Gwang Hee;Lee, Jang Yong;Lee, Sang Jeong
    • Journal of Positioning, Navigation, and Timing
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    • v.11 no.2
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    • pp.135-146
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    • 2022
  • In GNSS, the structure of the navigation message has been improved to increase the flexibility of data addition and transmission, and the robustness of message reception in a low SNR environment. GNSS signals currently being broadcast have a different message structure from each other, and the structure can be largely classified into the fixed structure, the packetized structure, and the packetized and fixed pattern structure. This paper analyzes the features of these three types of structures and compares the performance using the indicators. It can be seen that the performance after adopting the packetized structure is superior to those of other structures. In particular, there has been remarkable improvement in terms of the message management and transmission efficiency.

Effective Self-Interference Cancellation for SSD(Simultaneous Single Band Duplex) System (SSD(Simultaneous Single Band Duplex) 시스템을 위한 효과적인 자기 간섭 제거 방법)

  • An, Changyoung;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.2
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    • pp.189-198
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    • 2014
  • In this paper, we propose a SSD(Simultaneous Single band Duplex) system using turbo equalizer with frame structure for simultaneous full-duplex communication in single band. the proposed system uses frame structure for self-interference cancellation effectively. In this paper, performance of the proposed system with frame structure compares to performance of SSD system without frame structure to analysis performance of the proposed system with frame structure. Simulation results show that the performance of proposed system with frame structure is batter than performance of SSD system without frame structure when the number of global iterations of both system is same. Using proposed system with frame structure, we can verify that the performance like SSD system without frame structure by few global iteration of turbo equalizer.

A Reduction method of Undesired Radiation from the Split Ground Structures (SGS)

  • Kim, Gi-rae
    • Journal of information and communication convergence engineering
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    • v.1 no.1
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    • pp.44-47
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    • 2003
  • The split ground structure for microstrip structure can be used to protect analog/RF signal from SSN interference of digital circuits on PCB with common ground. However, the split ground structure gives rise to undesired emissions that may interfere with nearby circuitry due to the ground discontinuity. In this paper, we have proposed the modified structure, Dumbbell shaped SGS and the method to reduce the radiation by adding the lumped resistor on the proposed Dumbbell shaped SGS.

A Study of Field-Ring Design using a Variety of Analysis Method in Insulated Gate Bipolar Transistor (IGBT)

  • Jung, Eun Sik;Kyoung, Sin-Su;Chung, Hunsuk;Kang, Ey Goo
    • Journal of Electrical Engineering and Technology
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    • v.9 no.6
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    • pp.1995-2003
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    • 2014
  • Power semiconductor devices have been the major backbone for high-power electronic devices. One of important parameters in view of power semiconductor devices often characterize with a high breakdown voltage. Therefore, many efforts have been made, since the development of the Insulated Gate Bipolar Transistor (IGBT), toward having higher level of breakdown voltage, whereby the typical design thereof is focused on the structure using the field ring. In this study, in an attempt to make up more optimized field-ring structure, the characteristics of the field ring were investigated with the use of theoretical arithmetic model and methodologically the design of experiments (DOE). In addition, the IGBT having the field-ring structure was designed via simulation based on the finding from the above, the result of which was also analyzed. Lastly, the current study described the trench field-ring structure taking advantages of trench-etching process having the improved field-ring structure, not as simple as the conventional one. As a result of the simulation, it was found that the improved trench field-ring structure leads to more desirable voltage divider than relying on the conventional field-ring structure.

Behavior Analysis of a Seismically Isolated NPP Structure by Varying Seismic Input Generation Method and Strong Ground Motion Duration (입력운동 생성방법과 강진지속시간에 따른 면진원전의 거동 분석)

  • Kim, Hyun-Uk;Joo, Kwang-Ho;Noh, Sang-Hoon;Jung, Chang-Gyun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.17 no.4
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    • pp.187-195
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    • 2013
  • In this paper, firstly, acceleration-time histories were generated by varying strong motion duration in the frequency domain for application to a seismically isolated nuclear power structure, so as to examine the effects of strong motion duration on the behavior of the structure. Secondly, real recorded earthquakes were modified to match the target response spectrum based on the revised SRP 3.7.1(2007) and the modified time histories were applied to the analysis of a seismically isolated nuclear power structure. The obtained values of acceleration and displacement responses of the structure were, finally, compared with the values obtained in case of applying acceleration-time histories generated in the frequency domain to the structure.

Analysis of Consciousness Structure R&D Project Evaluation (연구개발 프로젝트 평가에 대한 의식구조분석)

  • 김성희;김정자
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.25 no.4
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    • pp.61-68
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    • 2002
  • This paper provides a method of consciousness structure analysis for research and development project evaluation using fuzzy structure modeling(FSM). Fuzzy structure modeling, which is a modeling method for consciousness structure, has a large number of pairwise comparison by human subjective judgement and is difficult to check the consistency index of denoting the precision for human judgement. Thus, in this paper, we analyzed the structure of consciousness by fuzzy structural modeling method, introducing the concept of pairwise comparison matrix in Analytic Hierarchy Process.