Applied Mechanics and Materials Vols. 513-517

Abstract: In this study, we developed a simple finger stimulator that can simultaneously control vibration and heat stimulation. The newly developed stimulator consists of three parts, namely the control unit, drive unit, and an actuator. The control unit controls the stimulation type, frequency, intensity, and time. The drive unit amplifies the stimulation signal that drives the actuator. The actuator displays the vibration and heat stimuli quantitatively and simultaneously. Although the developed stimulator is simple, it has a wide frequency range of 0-400 Hz comprising 40 levels, and vibration stimulation intensity comprising 50 levels. The control temperature and stimulation temperature used for heat stimulation comprise four and eight levels, respectively. In addition, the developed stimulator has many advantages in terms of the overall system, stimulation control, and safety. Therefore, the developed stimulator can be used for integrative tactile perception and cognition studies on various vibration and heat sensations.

Abstract: Crime rates especially atrocities involving women have been ever increasing. Even in the presence of technologies like cell phones, tablets; people can hardly make use of them in their hour of need to prevent or at least halt misfortunes because of the promptness which such situations demands. This paper proposes a solution for maximizing the usage of technology in preventing crimes such as rape through the development of an automated system that will be able to gauge fear of a prospective victim and click pictures of the prospective criminal (s) and send them along with GPS coordinates or location information to the nearest police station and the relatives of the prospective victim. The proposed system can also be useful in aiding anti-theft systems in houses and stores.

Abstract: This paper discusses concerning design of circular patch microstrip antenna for Radio Frequency Identification (RFID) tags application in microwave band. Circular microstrip antenna is designed with an egg slot on the ground plane and feed line to get ultra wideband. The design of microstrip antenna using Phenolic White Paper-FR2 with dielectric constant (o_r) =4.5. Based on simulation results, the antenna shows it works at frequency 2128-4807 MHz with gain of-17,398 dBi. The rectangular stub, caused the decreasing of bandwidth but the gain increase. By adding a rectangular stub on the ground plane, antenna works at frequency 1166 3475 MHz with increasing gain of-2,733 dBi.

Abstract: Within a smart space where users are provided with proactive services and enhanced interaction experiences, context-awareness is one of the fundamental requirements. Upon representing and deriving higher-level contextual knowledge from sensory observations, especially where the target environment involves physical spaces and objects, their spatial characteristics are the major elements for monitoring and understanding meaningful contexts and their changes. This paper outlines our context representation and reasoning approach based on spatial objects, along with a layered knowledge model for contextual knowledgebase and the reasoning process for higher-level context generation.

Abstract: In this paper, an amplify-and-forward (AF) multi-relay network is considered. In order to minimize the system outage probability, a new power allocation and multi-relay selection algorithm is proposed under total power constraint and each node power constraint. In the proposed algorithm, the ideal of ordering is adopted, which leads to the remarkable decrease of the computation complexity together with simple power reallocation. Simulation results show that the proposed multi-relay selection algorithm performs close to the optimal scheme with optimal power allocation and exhaustive search (OPA-ES) but with much lower complexity.

Abstract: Spatial Modulation is a kind of spatial multiplexing schemes conveying information by the location of transmit antennas and spatial modulation (SM) along with OFDM can be applied to visible light communications for higher data rates. The closed form of symbol error rate (SER) in optical SM-OFDM communication system is derived in this paper. SER is a convex function of power allocation coefficients, therefore there exist optimal allocation coefficients minimizing SER. The optimal allocation coefficients are derived for different channels and numbers of transmit antennas. Analytical results are validated by Monte Carlo simulation results and these results show that a significant SER improvement is obtained by using the power allocation. In addition, the optimal allocation coefficients are affected by the channel and number of transmitters.

Abstract: A novel photovoltaic (PV) system is proposed, which exhibits the advantages of better protection and more efficient control on charge/discharge of the battery. Furthermore, it can realize power management of the system. The key point of power management is how to control the bi-directional converter effectively. Considering traditional soft start strategy would be ineffective for bi-directional converter in the double sources application for the possibility of damaging the power device, a new soft start control method named delay synchronizing rectification control method is proposed. A 500W prototype converter is built to verify the theoretical analysis and the control method.

Abstract: A novel power management control strategy for photovoltaic power system is proposed. The solar cell array powers the steady state energy and the battery compensates the dynamic energy in the system. The goal of the power management control strategy is to control the un-directional DC-DC converter and bi-direction DC-DC converter to operate in suitable modes according to the condition of solar cell and battery, so as to coordinate the two sources of solar cell and battery supplying power and ensure the system operates with high efficiency and behaviors with good dynamic performance. A 500W experimental prototype of photovoltaic power system was built in the lab. Experimental results are shown to verify the effectiveness of the proposed power management strategy..

Abstract: For the problem of high intensity, low efficiency and poor accuracy in the artificial classification of navel oranges, a detection method is proposed based on machine vision technology. In defect detection, we analyze the color information of navel oranges surface, and obtain surface defect with a proper ratio of R/B and G/B. In the detection of color and luster, we calculate the texture information of the grayscale image, and propose three characteristics such as smoothness R, "consistency" measure U and entropy descriptor e. Finally, a hierarchical model is established based on BP neural network. The test results show that this method can be used for detecting the color and luster of navel orange with a high recognition rate.

Abstract: A dynamic model was established using the virtual spring approach for the underactuated prosthetic finger containing the closed kinematic chains and holonomic constraints. The dynamic model was verified by grasp simulation. The virtual spring is used to approximate the constraint force and differential algebraic equations are converted into ordinary differential equations which are ideal for simulation and real-time control. The grasp characteristics of the underactuated finger were studied based on the model with the stiffness of the linear springs as variables. By properly increasing the stiffness of springs, the grasp stability of underactuated finger could be improved and ejection phenomenon would be reduced. However, self-adaptive capability would be reduced with large stiffness. A characteristic index was used for estimating grasp stability and self-adaptive capability. The simulation results show that setting the stiffness of the linear springs between 1N/mm and 2N/mm is the best choice for the underactuated finger.