• Title/Summary/Keyword: Micro features

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Increasing Flight Endurance of MAVs using Multiple Quantum Well Solar Cells

  • Hassanalian, Mostafa;Radmanesh, Mohammadreza;Sedaghat, Ahmad
    • International Journal of Aeronautical and Space Sciences
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    • v.15 no.2
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    • pp.212-217
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    • 2014
  • Micro Aerial Vehicles (MAVs) are useful devices to assess new features that may be utilized in a full size aircraft to enhance performance or to increase endurance. In this article, sources for energy saving in the micro air vehicles are initially addressed. Then, by specifying the important parameters on energy consumption of an aircraft, a feasibility study is conducted to assess the benefit of using solar cells to increase flight endurance. Next, a new solar cell has been designed and optimized for MAVs. This cell consists of a multiple quantum wells for which the quantum factor and the absorption coefficient are calculated by solving the Shrodinger equation using MATLAB software. Then, the manner and influence of MAVs parameters using the solar cells are examined to suggest optimal planform for different purposes. In order to increase flight endurance, it is noted that by using appropriate planform and the optimized solar cells, flight endurance can be increased by more than 30 percent.

MicroRNA-203 As a Stemness Inhibitor of Glioblastoma Stem Cells

  • Deng, Yifan;Zhu, Gang;Luo, Honghai;Zhao, Shiguang
    • Molecules and Cells
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    • v.39 no.8
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    • pp.619-624
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    • 2016
  • Glioblastoma stem cells (GBM-SCs) are believed to be a subpopulation within all glioblastoma (GBM) cells that are in large part responsible for tumor growth and the high grade of therapeutic resistance that is so characteristic of GBM. MicroRNAs (miR) have been implicated in regulating the expression of oncogenes and tumor suppressor genes in cancer stem cells, including GBM-SCs, and they are a potential target for cancer therapy. In the current study, miR-203 expression was reduced in $CD133^+$ GBM-SCs derived from six human GBM biopsies. MicroRNA-203 transfected GBM-SCs had reduced capacity for self-renewal in the cell sphere assay and increased expression of glial and neuronal differentiation markers. In addition, a reduced proliferation rate and an increased rate of apoptosis were observed. Therefore, miR-203 has the potential to reduce features of stemness, specifically in GBM-SCs, and is a logical target for GBM gene therapy.

低電力 MCU core의 設計에 對해

  • An, Hyeong-Geun;Jeong, Bong-Yeong;No, Hyeong-Rae
    • The Magazine of the IEIE
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    • v.25 no.5
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    • pp.31-41
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    • 1998
  • With the advent of portable electronic systems, power consumption has recently become a major issue in circuit and system design. Furthermore, the sophisticated fabrication technology makes it possible to embed more functions and features in a VLSI chip, consequently calling for both higher performance and lower power to deal with the ever growing complexity of system algorithms than in the past. VLSI designers should cope with two conflicting constraints, high performance and low power, offering an optimum trade off of these constraints to meet requirements of system. Historically, VLSI designers have focused on performance improvement, and power dissipation was not a design criteria but an afterthought. This design paradigm should be changed, as power is emerging as the most critical design constraint. In VLSI design, low power design can be accomplished through many ways, for instance, process, circuit/logic design, architectural design, and etc.. In this paper, a few low power design examples, which have been used in 8 bit micro-controller core, and can be used also in 4/16/32 bit micro-controller cores, are presented in the areas of circuit, logic and architectural design. We first propose a low power guidelines for micro-controller design in SAMSUNG, and more detailed design examples are followed applying 4 specific design guidelines. The 1st example shows the power reduction through reduction of number of state clocks per instruction. The 2nd example realized the power reduction by applying RISC(Reduced Instruction Set Computer) concept. The 3rd example is to optimize the algorithm for ALU(Arithmetic Logic Unit) to lower the power consumption, Lastly, circuit cells designed for low power are described.

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Micro-Cracked Textile Composite Structures‘ Behavior on the Dynamic Impact Loading (동적 충격하중에 의한 미소균열 직조복합구조의 특성)

  • Hur, Hae-Kyu;Kim, Min-Sung;Jung, Jae-Kwon;Kim, Yong-Jin
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.222-227
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    • 2008
  • This study is focused on an integrated numerical modeling enabling one to investigate the dynamic behavior and failure of 2-D textile composite and 3-D orthogonal woven composite structures weakened by micro-cracks and subjected to an impact load. The integrated numerical modeling is based on: I) determination of governing equations via a three-level hierarchy: micro-mechanical unit cell analysis, layer-wise analysis accounting for transverse strains and stresses, and structural analysis based on anisotropic plate layers, II) development of an efficient computational approach enabling one to perform transient response analyses of 2-D plain woven and 3-D orthogonal woven composite structures featuring the matrix cracking and exposed to time-dependent loads, III) determination of the structural characteristics of the textile-layered composites and their degraded features under various geometrical yarn shapes, and finally, IV) assessment of the implications of stiffness degradation on dynamic response to impact loads.

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Religion and Banking : A Study of Islamic Finance in India

  • Baber, Hasnan;Zaruova, Chinar
    • The Journal of Industrial Distribution & Business
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    • v.9 no.6
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    • pp.7-13
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    • 2018
  • Purpose - The purpose of this paper is to elucidate the limelight question 'why India should open arms for Islamic banking?'. Research design, data, and methodology - The paper is theoretical and conceptual in nature and provides results based on significant literature review. Results - This paper will start with the discussion why Islamic name does not make it only for Muslims?, then its features and how it can improve India's current economic situation. Also this study will analyze the ability of Islamic finance to act as Micro-finance tool by including people who does not participate in economic activities. This paper also concludes that why religious issue should be sidelined in order to accept Islamic finance for empowerment of Muslim and non-Muslim minorities which live in abject poor conditions. Conclusions - Islamic finance has lot of merits which cannot be ignored by only looking at the name and believing that it is only for Muslims. Indian economic system needs a financial system which will work for welfare and not for profit to help poor communities in coming out of poverty. Interest free loans and micro-finance tools are the only way to help below poverty line population to raise their income level.

A Hybrid of Smartphone Camera and Basestation Wide-area Indoor Positioning Method

  • Jiao, Jichao;Deng, Zhongliang;Xu, Lianming;Li, Fei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.2
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    • pp.723-743
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    • 2016
  • Indoor positioning is considered an enabler for a variety of applications, the demand for an indoor positioning service has also been accelerated. That is because that people spend most of their time indoor environment. Meanwhile, the smartphone integrated powerful camera is an efficient platform for navigation and positioning. However, for high accuracy indoor positioning by using a smartphone, there are two constraints that includes: (1) limited computational and memory resources of smartphone; (2) users' moving in large buildings. To address those issues, this paper uses the TC-OFDM for calculating the coarse positioning information includes horizontal and altitude information for assisting smartphone camera-based positioning. Moreover, a unified representation model of image features under variety of scenarios whose name is FAST-SURF is established for computing the fine location. Finally, an optimization marginalized particle filter is proposed for fusing the positioning information from TC-OFDM and images. The experimental result shows that the wide location detection accuracy is 0.823 m (1σ) at horizontal and 0.5 m at vertical. Comparing to the WiFi-based and ibeacon-based positioning methods, our method is powerful while being easy to be deployed and optimized.

Development of Non-contact Image Measuring Technique for Evaluating Micro-relief (미세주름 측정을 위한 비접촉식 영상측정기술의 발전)

  • Kim, Nam-Soo;Kim, Yong-Min
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.31 no.3 s.52
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    • pp.253-257
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    • 2005
  • Assurance of the objectivity and reproducibility is a major key point in wrinkle measurement used for evaluating the degree of skin aging. The measurement of relief is quickly converted to a non-contact method, of which tools or instruments do not come in contact with skin directly, to minimize the artificial effects which influence the shape or depth of the relief. Here, we showed how wrinkle measurement techniques have been changed briefly and compared PRIMOS and replica method in the point of view of measurement principle and features, the former is non-contact fringe projection tool and the latter is contact type of the method.

Development of High Performance Micro Turbojet Engine (고성능 초소형 터보제트엔진 개발)

  • Paeng, Ki-Seok;Ahn, Chul-Ju;Min, Seong-Ki;Kim, Yu-Il
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.548-551
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    • 2010
  • A 150 lbf-thrust class micro turbojet engine has been developed. The engine could be applied to power plant for small aviation vehicle such as UAV, decoy and anti-radar missile and was designed with concepts that has small size, low-cost and high performance. A prototype was manufactured and performed the ground static test and high altitude test. This paper outlines the features and layout of 150 lbf turbojet engine and also describes the design characteristics and test results of the engine and components.

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A Study on the Characteristics of Silicon Micro-hole machining (단결정 실리콘 미세 홀 가공특성에 관한 연구)

  • Chae, Seung-Su;Lee, Sang-Min;Park, Hwi-Keun;Cho, Jun-Hyun;Lee, Jong-Chan;Heo, Chan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.2
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    • pp.75-80
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    • 2013
  • Cathode is an essential component used in plasma etching process which is to make micro pattern on the silicon wafer. The currently used cathodes produce particles at the high temperature plasma etching process. To overcome this problem, a 'Silicon Only Cathode' was developed. This 'Silicon Only Cathode' requires manufacturing process changes due to the change of shapes, material features, and machining characteristics of work materials. This research investigates the small hole drilling process. The conclusion is that PCD drills with twist angles of $20^{\circ}$ and $25^{\circ}$ were tested for small hole drilling and the experimental results indicate that the drill with $25^{\circ}$ twist angle drill causes less thrust force.

Dynamics Analysis of Industrial Robot Using Neural Network (뉴럴네트워크를 이용한 산업용 로봇의 동특성 해석)

  • Lee, Jin
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1997.04a
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    • pp.62-67
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    • 1997
  • This paper reprdsents a new scheme of neural network control system analysis the robustues of robot manipulator using digital signal processors. Digtal signal processors, DSPs, are micro-processors that are particularly developed for fast numerical computations involving sums and products of variables. Digital version of most advanced control algorithms can be defined as sums and products of measured variables, thus it can be programmed and executed through DSPs. In additions, DSPs are a s fast in computation as most 32-bit micro-processors and yet at a fraction of their prices. These features make DSPs a viable computational tool in digital implementation of sophisticated controllers. Durng past decade it was proposed the well-established theorys for the adaptive control of linear systems, but there exists relatively little general theory for the adaptive control of nonlinear systems. The proposed neuro network control algorithm is one of learning a model based error back-propagation scheme using Lyapunov stability analysis method.

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