Seoul, South Korea

Time filter

Source Type

Choi K.-H.,Korea Polytechnic University | Ang B.W.,National University of Singapore
Energy Economics | Year: 2012

In this paper we extend the methodology of index decomposition analysis (IDA) in energy studies by quantifying the contribution of individual attributes to the percent change of factors such as the real energy intensity index and structural change index. We apply the proposed method to the real energy intensity index in the multiplicative Logarithmic Mean Divisia Index (M-LMDI) approach, a major IDA technique. Since the M-LMDI is based on geometric mean type indices and chain computation, we need some appropriate method to cope with the difficulties that arise. We present a numerical illustration of the proposed method using the energy consumption and real value added data of the US manufacturing industry, and compare the results obtained by the Fisher real energy intensity index. © 2011 Elsevier B.V.

Korea Polytechnic University and Samsung | Date: 2011-12-20

A method of processing an image signal includes: converting a source image signal into an image signal corresponding to a color space for a color gamut mapping; reducing a color gamut of the image signal; and mapping the image signal corresponding to colors within the reduced color gamut into an image signal corresponding to colors within a display color gamut, wherein the colors of the display color gamut are displayed by a display panel.

Kim P.-S.,Korea Polytechnic University
Digital Signal Processing: A Review Journal | Year: 2010

To overcome the resulting problems of existing finite impulse response (FIR) structure filters, this paper proposes an alternative FIR filter for state estimation in discrete-time systems, which is derived from the well-known Kalman filter with recursive infinite impulse response (IIR) structure. The proposed FIR filter obtains a posteriori knowledge about the window initial condition from the most recent finite observations, while existing FIR filters handle this task arbitrarily or heuristically. The gain matrix for the proposed FIR filter incorporates a posteriori knowledge about the window initial condition during its design and is shown to be time-invariant. The proposed FIR filter is shown to have good inherent properties such as unbiasedness and deadbeat. Through extensive computer simulations, the proposed FIR filter can be shown to be comparable with the Kalman filter for the nominal system and better than that for the temporarily uncertain system. © 2009 Elsevier Inc. All rights reserved.

Korea Polytechnic University | Date: 2016-02-04

An energy storage system (ESS) includes a battery pack, a power converter, a battery management system (BMS) configured to control and monitor, in real time, the battery pack, a load power controller coupled to the battery pack and an external power source, connected to loads, and an integrated controller configured to control an operation of each component, determine an exclusive supply initiation time based on energy management schedule information including the exclusive supply initiation time, an exclusive supply termination time, and power supply timing information, control power to be supplied to the loads exclusively using power of the battery pack at the exclusive supply initiation time, and, when a current residual charge amount of the battery pack is at least one residual charge amount in the power supply timing information, control power supply to one of the loads set to correspond to the residual charge amount to be cut.

A muscular strength enhancing robot to be driven by an intention of a user and a method of driving the robot are disclosed. The robot includes an actuator attached to a portion of a body of the user and configured to be actuated by enhancing a muscular strength, an encoder connected to the actuator and configured to measure an actual velocity at which the actuator moves, a force or torque sensor configured to measure an intensity of a force to be applied, an admittance modeling module configured to calculate a target velocity using the intensity of the force, and a proportional integral derivative (PID) control module configured to control actuation of the actuator in proportion to a velocity difference between the target velocity and the actual velocity, control the actuation by a cumulative value of the velocity difference, and control the actuation by a difference between a previous and a current velocity difference.

The present invention relates to a system and a method for controlling a joint angle of a knee-joint type walking training robot which estimates a walking stage of a person receiving rehabilitation for walking and actively responds to the walking stage on the basis thereof. The present invention can easily control the joint angle of the knee-joint type walking training robot by providing a configuration comprising: a pressure measuring device for measuring the pressure on the sole of a walkers foot by using a pressure sensor; and a joint angle estimating device for estimating the joint angle of a knee-joint by extracting movement time of the walk and the length of the part of the sole contacting the ground on the basis of the soles pressure measured by the pressure measuring device.

A vertical type light emitting diode includes a nitride semiconductor having a p-n conjunction structure with a transparent material layer formed on a p type clad layer, the transparent material layer having a refractive index different from that of the p type clad layer and having a pattern structure of mesh, punched plate, or one-dimensional grid form, etc. A reflective metal electrode layer is formed on the transparent material layer as a p-electrode. A stereoscopic pattern is formed in the transparent material layer and the p-electrode deposited, and thereby forming the pattern in the p-electrode. Depositing the p-electrode on only 10 to 70% of the upper portion of the p type clad layer in an ultraviolet ray light emitting diode such that an area where the p type clad layer is exposed is wide increases the transmittance of ultraviolet rays through an area where the p-electrode is not deposited.

Korea Polytechnic University and Seoul Opto Device Co. | Date: 2010-08-27

Provided are a high-quality non-polar/semi-polar semiconductor device having reduced defect density of a nitride semiconductor layer and improved internal quantum efficiency and light extraction efficiency, and a manufacturing method thereof. The method for manufacturing a semiconductor device is to form a template layer and a semiconductor device structure on a sapphire, SiC or Si substrate having a crystal plane for a growth of a non-polar or semi-polar nitride semiconductor layer. The manufacturing method includes: forming a nitride semiconductor layer on the substrate; performing a porous surface modification such that the nitride semiconductor layer has pores; forming the template layer by re-growing a nitride semiconductor layer on the surface-modified nitride semiconductor layer; and forming the semiconductor device structure on the template layer.

Korea Polytechnic University | Date: 2011-05-20

An interface device for an emulator is disclosed. The interface device includes a connection unit, a transmission unit, and an interface unit. The connection unit receives data, to be used to emulate a logic, from a host computer, and transmits result data, output from the logic, to the host computer. The transmission unit receives the data from the connection unit and stores (writes) the data in the first area of a register array. If the result data is stored in the second area of the register array, the transmission unit reads the result data and transmits the result data to the connection unit. The interface unit includes at least one register array, outputs a clock, set using the data stored in the first area, to the logic, and stores the result data, output from the logic, in the second area.

Korea Polytechnic University | Date: 2010-07-05

Provided is a multiple transposition method for superconducting wire, by making each superconducting wire unit from second-generation superconducting wires that were firstly transposed and then transposing each superconducting wire unit in such a manner that the phase of each unit can be changed along the length, comprising preparing wires by making curves on superconducting wires in such a manner that the superconducting wires of a thin multiple layer grown epitaxially are slit in zigzags and then making the curves repeatedly and by machining the wires with a desired length; making first-transposed superconducting wire units by combining a plurality of the prepared wires such that curves of adjacent wires come in touch to each other and are superposed; preparing a superconducting wire unit bundle by arranging the first-transposed superconducting wires units and by locating a plurality of the first-transposed superconducting wire units in parallel along the length; and making a second transposition on the first-transposed superconducting wire units by rotating the plurality of superconducting wire units on the central axis of the superconducting wire unit bundle along the length to be twisted and combined with each other.

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