Volume 2 Issue 4
Authors: Nanna Westergard-Nielsen; Martin Christian N?rgaard
Abstract: This paper describes a case, which demonstrates how a new media, the smartphone, can be used in the creation of Open Air Museums, called Street Museums. The main goal of the project is to demonstrate how a guided tour, based on a historic survey, in a local area with the participation of local people, can be created. The subject leads to a discussion on how a user-oriented study of place can be used in context-aware computing for location-based services.
Keywords: Interaction Design; Augmented Reality; Contextual Design; Street Museum; Memory Lane; Etnographic Methods; Human Computer Interfaces; Context Aware Computing; Local History; City Planning
Authors: Tanya K. Gachovska; Jerry L. Hudgins
Abstract: A power electronic device for a converter must possess a low specific on-resistance. The specific on-resistance of a bipolar device is related to the base width and doping concentration of the lightly doped drift region (n- base). Therefore, the doping concentration and the width of the low-doped base region in a bipolar device must be carefully considered to achieve a desired avalanche breakdown voltage and on-resistance (conduction characteristics). This work presents an improved method for calculation of the minimum depletion layer width for a given breakdown voltage of Si, SiC, and GaN structures and further investigates the optimum width of their depletion layers for different blocking voltages to achieve a minimal forward drop. The results show that an optimization of the forward voltage drop by using the optimal doping concentration for corresponding breakdown voltages is necessary for the proper design of a Si diode but is not necessary for wide band gap material devices.
Keywords: Forward Voltage Drop; Si; SiC; GaN
Authors: Jie Kong; Yule Yuan; Yong Zhao; Xinan Wang
Abstract: In this paper, we use edge information to fast intra mode decision and improve the performance of binary block motion estimation. For intra mode decision, we present a very simple, yet efficient, algorithm in AVS video coding based on edges detection and Support Vector Machine (SVM). The technique uses the SOBEL operator to check the edge information from the total image before its intra prediction. Then we use SVM classifier which is trained by the edge points to decide the mode of block for AVS intra prediction. Because only one prediction mode is chosen for rate-distortion optimization calculation using the proposed algorithm, simulation results also show that the proposed scheme achieves up to 16% computational saving with no video quality degradation, compared with results of the existing method. For binary block motion estimation, we studied that 2BT utilizes mean and standard deviation of a transforming block to get the two bit-planes. Due to the binary blocks coming from local adaptive thresholds, the binary blocks do not take advantage of global information. In the proposed 2BTGLE method, we use one global threshold and one local threshold to get the two bit-planes. The experiments demonstrated that our algorithm gets better performance than the 2BT method.
Keywords: Video Coding; Intra Prediction; Motion Estimation; SOBEL; SVM; 2BT
Authors: Seyed Abolfazl Seyed Abolfazl Fakoorian1; Gholamreza Mohammaddadi
Abstract: We can use specific control algorithms for generating the maximum possible power in photovoltaic power systems. Several methods to determine the optimum working point have been introduced in recent decades. In Maximum Power Point Tracking (MPPT) methods, the ideal operation is to determine the maximum power point (MPP) of the photovoltaic (PV) array directly rather than track it by using the active operation of trial and error, which causes undesirable oscillation around the MPP. Since the output characteristics of a PV cell with environmental changes such as radiation and temperature levels can change from moment to moment, Therefore, in order to identify the optimum operating point tracking of PV power systems are used in real time. In this paper, several methods are introduced to identify the optimum operating point and because of measurement power is usually associated with noise, Kalman filter and the position error are used to estimate the optimum operating point.
Keywords: Method of Least Squares; the Position Error; Parameter Estimation; Real- Time System and the Kalman Filter