• Title/Summary/Keyword: proximity function

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On the Length Scale and the Wall Proximity Function in the Mellor-Yamada Level 2.5 Turbulence Closure Model for Homogeneous Flows

  • Lee, Jong-Chan;Jung, Kyung-Tae
    • Journal of the korean society of oceanography
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    • v.32 no.2
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    • pp.75-84
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    • 1997
  • Relation between the length scale and the wall proximity function in the Mellor-Yamada level 2.5 turbulence closure model has been investigated through various experiments using a range of wall proximity functions. The model performance has been evaluated quantitatively by comparing with laboratory data for wind-driven flow (Baines and Knapp, 1965) and for open-channel flows without and with adverse wind action (Tsuruya, 1985). Comparison shows that a symmetric wall proximity function used by Blumberg and Mellor(1987) gives rise to current profiles with better accuracy than asymmetric wall proximity functions considered. It is noted that in modelling homogeneous flows the length scale 1= 0.31${\|}$z${\|}$(1+z/h) can be used with tolerable accuracy.

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An Efficient Inter-Cell Interference Mitigation Scheme for Proximity Service in Cellular Networks (셀룰러 망에서 Proximity Service를 위한 효율적인 셀 간 간섭 완화 방안)

  • Kim, Cha-Ju;Min, Sang-Won
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.17 no.1
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    • pp.100-113
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    • 2018
  • The Proximity Service, which is one of the most popular network capacity improvement methods, uses the frequency reuse in order to increase the frequency efficiency. As a result, inter-cell interference between cellular and proximity service users occurs at a cell edge. In this paper, we proposed a mitigation scheme for inter-cell interference, where we suggested a new function of and eNB with ProSe function exchanging information about ProSe parameters and ProSe user equipment with neighboring cells via the X2 interface. As the first step, the resource which did not cause the inter-cell interference problem were pre-allocated through the frequency sensing in the ProSe direct discovery. As the next step, the inter-cell interference problem was solved by reallocating appropriate resources based on the ProSe application code, the ProSe application QoS, the ProSe application ID and validity timer in ProSe direct communication.

ON COMPLEXITY ANALYSIS OF THE PRIMAL-DUAL INTERIOR-POINT METHOD FOR SECOND-ORDER CONE OPTIMIZATION PROBLEM

  • Choi, Bo-Kyung;Lee, Gue-Myung
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.14 no.2
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    • pp.93-111
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    • 2010
  • The purpose of this paper is to obtain new complexity results for a second-order cone optimization (SOCO) problem. We define a proximity function for the SOCO by a kernel function. Furthermore we formulate an algorithm for a large-update primal-dual interior-point method (IPM) for the SOCO by using the proximity function and give its complexity analysis, and then we show that the new worst-case iteration bound for the IPM is $O(q\sqrt{N}(logN)^{\frac{q+1}{q}}log{\frac{N}{\epsilon})$, where $q{\geqq}1$.

The Proximity Scheme of the Perceptual Space for Indexing The Trajectories of Tags (태그 궤적 색인을 위한 인식공간 근접성 기법)

  • Kim, Dong-Hyun;Ahn, Swng-Woo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.10
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    • pp.2140-2146
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    • 2009
  • Since tags do not have location informations, the identifiers of tags which are symbolic data are used as the location informations. Therefore, it is difficult to define the proxmity between two trajectories of tags and inefficient to process the user queries for tags. In this paper, we define the perceptual space to model the location of a tag and propose the proximity of the perceptual spaces. The proximity of the perceptual spaces is composed of the static proximity and dynamic proximity. Using the proximity of the perceptual spaces, it is possible to measure the proximity between two trajectories of tags and build the efficient indexes for tag trajectories. We evaluated the performance of the proposed proximity function for tag trajectories on the IR-tree and the $R^*$-tree.

Compliant Ultrasound Proximity Sensor for the Safe Operation of Human Friendly Robots Integrated with Tactile Sensing Capability

  • Cho, Il-Joo;Lee, Hyung-Kew;Chang, Sun-Il;Yoon, Euisik
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.310-316
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    • 2017
  • The robot proximity and tactile sensors can be categorized into two groups: grip sensors and safety sensors. They have different performance requirements. The safety sensor should have long proximity range and fast response in order to secure enough response time before colliding with ambient objects. As for the tactile sensing function, the safety sensor need to be fast and compliant to mitigate the impact from a collision. In order to meet these requirements, we proposed and demonstrated a compliant integrated safety sensor suitable to human-friendly robots. An ultrasonic proximity sensor and a piezoelectric tactile sensor made of PVDF films have been integrated in a compliant PDMS structure. The implemented sensor demonstrated the maximum proximity range of 35 cm. The directional tolerance for 30 cm detection range was about ${\pm}15^{\circ}$ from the normal axis. The integrated PVDF tactile sensor was able to detect various impacts of up to 20 N in a controlled experimental setup.

Proximity Effect in Nb/Gd Layers

  • Jung, Dong-Ho;Char, K.
    • Progress in Superconductivity
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    • v.12 no.2
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    • pp.110-113
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    • 2011
  • We have grown a Nb/Gd bilayer on a$SiO_2$/Si substrate by using a DC magnetron sputtering system, which was fabricated in situ with silicon stencil masks. In order to investigate proximity effect of the Nb/Gd bilayer, we used a planar tunnel junction with an AlOx tunnel barrier by oxidizing the Al ground electrode at the bottom. A $Co_{60}Fe_{40}$ backing of Al was deposited so as to reduce the superconductivity of the Al, ensuring a normal counterelectrode. With a 50-nm-thick Nb layer, we have measured dI/dV (dynamic conductance) by varying the thickness of Gd, which can reveal the density of states (DOS) of the Nb/Gd bilayer as a function of the Gd thickness resulting from the proximity effect of a superconductor/ferromagnet bilayer (S/F). The SF proximity effect in Nb/Gd will be discussed in comparison to our previous results of the CoFe/Nb, Ni/Nb and CuNi/Nb proximity effect; Gd is expected to show different effects since Gd has f-electrons, while CoFe, Ni, and CuNi have only d-electrons. Our studies will focus on the triplet correlation in a superconducting pair.

A Compact Low-Power Shunt Proximity Touch Sensor and Readout for Haptic Function

  • Lee, Yong-Min;Lee, Kye-Shin;Jeong, Taikyeong
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.3
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    • pp.380-386
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    • 2016
  • This paper presents a compact and low-power on-chip touch sensor and readout circuit using shunt proximity touch sensor and its design scheme. In the proposed touch sensor readout circuit, the touch panel condition depending on the proximity of the finger is directly converted into the corresponding voltage level without additional signal conditioning procedures. Furthermore, the additional circuitry including the comparator and the flip-flop does not consume any static current, which leads to a low-power design scheme. A new prototype touch sensor readout integrated circuit was fabricated using complementally metal oxide silicon (CMOS) $0.18{\mu}m$ technology with core area of $0.032mm^2$ and total current of $125{\mu}A$. Our measurement result shows that an actual 10.4 inches capacitive type touch screen panel (TSP) can detect the finger size from 0 to 1.52 mm, sharply.

Laser Process Proximity Correction for Improvement of Critical Dimension Linearity on a Photomask

  • Park, Jong-Rak;Kim, Hyun-Su;Kim, Jin-Tae;Sung, Moon-Gyu;Cho, Won-Il;Choi, Ji-Hyun;Choi, Sung-Woon
    • ETRI Journal
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    • v.27 no.2
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    • pp.188-194
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    • 2005
  • We report on the improvement of critical dimension (CD) linearity on a photomask by applying the concept of process proximity correction to a laser lithographic process used for the fabrication of photomasks. Rule-based laser process proximity correction (LPC) was performed using an automated optical proximity correction tool and we obtained dramatic improvement of CD linearity on a photomask. A study on model-based LPC was executed using a two-Gaussian kernel function and we extracted model parameters for the laser lithographic process by fitting the model-predicted CD linearity data with measured ones. Model-predicted bias values of isolated space (I/S), arrayed contact (A/C) and isolated contact (I/C) were in good agreement with those obtained by the nonlinear curve-fitting method used for the rule-based LPC.

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A Gate Delay Model Considering Temporal Proximity of Multiple Input Switching (다중 입력 변화의 시간적 근접성을 고려한 게이트 지연 시간 모델)

  • Shin, Jang-Hyuk;Kim, Ju-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.2
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    • pp.32-39
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    • 2010
  • Conventional cell characterization does not consider Multiple Input Switching(MIS). Since the impact of MIS on gate delay variation is large, it is not possible to predict the accurate gate delay with the conventional cell characterization. We observed the maximum 46% difference in gate delay due tn MIS. In this paper, we propose a gate delay model considering the delay variation caused by the temporal proximity of MIS. The proposed model calculates the delay variation using the Radial Basis Function. The experimental results show that the proposed method can more accurately predict the gate delay when MIS occurs.

Modeling of Bank Asset Management System based on Intelligent Agent

  • Kim, Dae-Su;Kim, Chang-Suk
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.1 no.1
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    • pp.81-86
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    • 2001
  • In this paper, we investigated the modeling of Bank Asset Management System(BAME) based on intelligent agent. To achieve this goal, we introduced several kinds of agents that show intelligent features. BAMS is a user friendly system and adopts fuzzy converting system and fuzzy matching system that returns reasonable similarity matching results. Generation function of the proximity degree is suggested. Fuzzification of investment type categories and feature values are defined, and generation of proximity degree is also derived. An example of bank asset management system is introduced and simulated. Investment type matching utilizing fuzzy measure is tested and it showed quite reasonable similarity matching results.

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