• Title/Summary/Keyword: non-local measurement

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Electrical Spin Transport in n-Doped In0.53Ga0.47As Channels

  • Park, Youn-Ho;Koo, Hyun-Cheol;Kim, Kyung-Ho;Kim, Hyung-Jun;Han, Suk-Hee
    • Journal of Magnetics
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    • v.14 no.1
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    • pp.23-26
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    • 2009
  • Spin injection from a ferromagnet into an n-doped $In_{0.53}Ga_{0.47}As$ channel was electrically detected by a ferromagnetic detector. At T = 20 K, using non-local and local spin-valve measurements, a non-local signal of $2\;{\mu}V$ and a local spin valve signal of 0.041% were observed when the bias current was 1 mA. The band calculation and Shubnikov-de Haas oscillation measurement in a bulk channel showed that the gate controlled spin-orbit interaction was not large enough to control the spin precession but it could be a worthy candidate for a logic device using spin accumulation and diffusion.

Efficient distributed estimation based on non-regular quantized data

  • Kim, Yoon Hak
    • Journal of IKEEE
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    • v.23 no.2
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    • pp.710-715
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    • 2019
  • We consider parameter estimation in distributed systems in which measurements at local nodes are quantized in a non-regular manner, where multiple codewords are mapped into a single local measurement. For the system with non-regular quantization, to ensure a perfect independent encoding at local nodes, a local measurement can be encoded into a set of a great number of codewords which are transmitted to a fusion node where estimation is conducted with enormous computational cost due to the large cardinality of the sets. In this paper, we propose an efficient estimation technique that can handle the non-regular quantized data by efficiently finding the feasible combination of codewords without searching all of the possible combinations. We conduct experiments to show that the proposed estimation performs well with respect to previous novel techniques with a reasonable complexity.

The Effect of Local Basis Weight on Local Strain (지역 평량이 지역 변형률에 미치는 영향)

  • 남원석;백기현
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.3
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    • pp.105-109
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    • 1999
  • The purpose of this experiment was to see the effect of local basis weight on the local strain during changing moisture content in handsheets. The averaged strain value of the whole size of paper sheet did not give more valuable information to explain non uniform deformation in the paper sheet. The combination of intact strain measurement system KISA (Linear Image Strain Analysis) and local basis weight measurement method using a scanner made it possible to compare local basis weight with local strain to explain moisture induced paper deformation . Usually higher basis weight local area showed higher moisture induced local strain. However, the hygro-induced strain values were highly affected by the behavior of neighbor local areas. Well distributed local basis weight paper would give more uniform local strains than those of non-uniformed local basis weight paper.

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Improvement of Image Processing Technique for Drop Size Measurement (입경 측정을 위한 영상 처리 기법의 개선)

  • Kim, Joo Youn;Chu, Jeong Ho;Lee, Sang Yong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.8
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    • pp.1152-1163
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    • 1998
  • In the present work, the image processing technique for measurement of drop sizes has been improved. Firstly, the local processing concept was adopted in addition to the global processing technique to take account of non-uniformity of the illumination intensity ; thereby, basically, the measurement error can be reduced. Also, the unfocussed image of drops can be eliminated more precisely since the elimination process is based on the local normalized contrast. Secondly the algorithms to process the partially detected or overlapped drop images and the non-spherical drop images were developed. Finally, the improved algorithm was tested by using an artificially prepared image-frame, where the partial or overlapped particles and the non-spherical particles are mixed with the normal spherical ones (with their true size-distributions known a priori). The results showed that both the recognition rate of the number of particles and the measurement accuracy were improved prominently.

A Study on the Measurement Methodology for Soft Tissue Deformation Using Laser Extensometer (레이저 변위계를 이용한 생체 연조직의 변형 측정법에 관한 연구)

  • 최경주;홍정화;문무성;이진희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.1085-1087
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    • 2002
  • Deformation of soft tissue is known inhomogeneous and non-linear in general. In this study, we propose a measurement methodology of local/global strain during soft tissue elongation precisely using laser extensometer which has high accuracy, resolution and is possible to measure global/local strain. The mechanical tensile test are performed on tibialis cranialis, flexor hallucis longus, extensor digitorum longus of swine hindlimb. In order to measure target displacement, reflective marker is attached to detect elongation on specimen using surgical adhesive. The result of this study is to show that laser extensometer is valid to measure longitudinal elongation which is inhomogeneous and non-linear fur soft tissue.

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A Location Technique Based On Calibrated Radio Frequency Propagation Model For Wireless Local Area Networks (교정된 전파전파 모델에 기반한 WLAN 측위 기법)

  • Kim, Hee-Sung;Shim, Ju-Young;Choi, Wan-Sik;Lee, Hyung-Keun
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.8
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    • pp.760-766
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    • 2008
  • This paper proposes an efficient location technique to find an indoor location under the IEEE 802.11 wireless local area networks. The proposed method is based on the range measurements obtained from a simple radio frequency propagation model. Thus, unlike the radio frequency fingerprint correlation method, it does not suffer from the computational burden during the real-time location service period and can quickly reply the location requests of many users at the same time. To increase the location accuracy in spite of the frequent non-line-of-sight error occurrences, the proposed method calibrates the distortion of the non-line-of-sight error by a simple measurement surveying procedure that does not require the surveyor's manual interaction. Experimental results show the capability of the proposed method.

A New Algorithm Based on ASH in Local Modes Detection of Pathrate (ASH를 이용한 Pathrate에서의 Local Mode 검출 알고리즘)

  • Huang, Yue;Kim, Yong-Soo
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.5 s.43
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    • pp.1-8
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    • 2006
  • Network measurement is a vital part of network traffic engineering. In a network, the metric 'capacity' characterizes the maximum throughput the path can provide when there is no traffic load, or the minimum transmission rate among all links in a path. Pathrate is one of the most widely used network capacity measurement tools nowadays. It's famous for its accurate estimation result and non restriction of the temporal network traffic condition. After several years of development, its performance becomes more stable and reliable. Extant local modes detection algorithm in pathrate is based on statistic methodology histogram. This paper suggests a new algorithm for local modes detection based on ASH (Averaged Shifted Histogram). We have implemented this algorithm and will prove it can accomplish the same task as the original one with a better result.

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Electrical spin injection and detection in epitaxially grown Fe/GaAs (001) hybrid structure (에피성장된 Fe/GaAs (001) 적층구조에서의 스핀 주입 및 검출)

  • Lee, Tae-Hwan;Koo, Hyun-Cheol;Kim, Kyung-Ho;Kim, Hyung-Jun;Han, Suk-Hee;Lim, Sang-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.357-357
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    • 2008
  • Spin injection experiment is conducted in epitaxially grown Fe/GaAs hybrid structure. For the formation of Schottky tunnel barrier between Fe and GaAs layers, highly n-doped GaAs layers are grown after n-doped channel layer. A non-local measurement, a voltage measurement probes do not contain a charge current path, is used for detecting only the chemical potential differences by the spin transport. As a result, the dips that are nicely matched with antiparallel region are obtained.

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Liftoff mechanisms in hydrogen turbulent non-premixed jet flames (수소 난류확산화염에서의 부상 메커니즘에 대한 연구)

  • Oh, Jeong-Seog;Kim, Mun-ki;Choi, Yeong-Il;Yoon, Young-Bin
    • 한국연소학회:학술대회논문집
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    • 2007.05a
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    • pp.7-12
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    • 2007
  • To reveal the newly found liftoff height behavior of hydrogen jet, we have experimentally studied the stabilization mechanism of turbulent, lifted jet flames in a non-premixed condition. The objectives of the present research are to report the phenomenon of a liftoff height decreasing as increasing fuel velocity, to analyse the flame structure and behavior of the lifted jet, and to explain the mechanisms of flame stability in hydrogen turbulent non-premixed jet flames. The velocity of hydrogen was varied from 100 to 300m/s and a coaxial air velocity was fixed at 16m/s with a coflow air less than 0.1m/s. For the simultaneous measurement of velocity field and reaction zone. PIV and OH PLIF technique was used with two Nd:Yag lasers and CCD cameras. As results, it has been found that the stabilization of lifted hydrogen diffusion flames is related with a turbulent intensity, which means that combustion occurs where the local flow velocity is valanced with the turbulent flame propagation velocity.

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Liftoff Mechanisms in Hydrogen Turbulent Non-premixed Jet Flames (수소 난류확산화염에서의 부상 메커니즘에 대한 연구)

  • Oh, Jeong-Seog;Kim, Mun-Ki;Choi, Yeong-Il;Yoon, Young-Bin
    • Journal of the Korean Society of Combustion
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    • v.12 no.2
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    • pp.26-33
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    • 2007
  • To reveal the newly found liftoff height behavior of hydrogen jet, we have experimentally studied the stabilization mechanism of turbulent, lifted jet flames in a non-premixed condition. The objectives of the present research are to report the phenomenon of a liftoff height decreasing as increasing fuel velocity, to analyse the flame structure and behavior of the lifted jet, and to explain the mechanisms of flame stability in hydrogen turbulent non-premixed jet flames. The velocity of hydrogen was varied from 100 to 300m/s and a coaxial air velocity was fixed at 16m/s with a coflow air less than 0.1m/s. For the simultaneous measurement of velocity field and reaction zone, PIV and OH PLIF technique was used with two Nd:Yag lasers and CCD cameras. As results, it has been found that the stabilization of lifted hydrogen diffusion flames is related with a turbulent intensity, which means that combustion occurs at the point where the local flow velocity is balanced with the turbulent flame propagation velocity.

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