Accuracy And Error Study Of Horizontal And Vertical Measurements With Single View Metrology For Road Surveying

High quality digital image can be produced and stored with cost effective embedded system, thanks to advancement of low power digital camera and hardware accelerated high definition video image compression System-on- Chip. Image recorded with these multi-megapixel digital cameras allowed the world to be digitized more accurately (compared with conventional VGA camera with low resolution) and hence enable the use of single image as the metrology tool. Using the single view geometry techniques (planar homography, vanishing points and vanishing lines) widely accepted by the community, the suitability of applying these techniques with error reduced for road surveying is studied and reported in this work

Evaluation of Image Pixels Similarity Measurement Algorithm Accelerated on GPU with OpenACC

OpenACC is a directive based parallel programming library that allows for easy acceleration of existing C, C++ and Fortran based applications with minimal code modifications. By annotating the bottleneck causing section of the code with OpenACC directives, the acceleration of the code can be simplified, leading for high portability of performance across different target Graphic Processing Units (GPUs). In this work, the portability of an implemented parallelizable chi-square based pixel similarity measurement algorithm has been evaluated on two consumer and professional grade GPUs. To our best knowledge, this is the first performance evaluation report that utilizes the OpenACC optimization clauses (collapse and tile) on different GPUs to process a less workload (low resolution image of 581x429 pixels) and a heavy workload (high resolution image of 4500 x 3500 pixels) to demonstrate the effectiveness and high portability of OpenACC

Analysis and Validation of The Effect of Various Queueing Configurations to the End-to-end Throughput of Multi-Hop Wireless Network

A multi-hop wireless network is created by connecting multiple wireless access points (APs) as the backhaul of the network to increase the network coverage. The issue of spatial bias, unbalanced network performance of end-to-end throughput and delay occurs when the total offered load of the associated stations to the backhaul exceeds the wireless link capacity. Station associated to the access point with more hops away from the gateway will experience a significant amount of delay and lower end-to-end throughput compared to the station with fewer hops to the gateway. The equality of local successful transmit probability and mesh successful transmit probability in congested APs, which is the main root cause of the spatial bias problem, is modelled and validated. If the packet arrival ratio of local over mesh ingress interface is larger than the respective queue length ratio, the mesh ingress interface successful transmit probability will be higher than the local ingress interface successful transmit probability and vice-versa. By controlling the ratio of queue lengths, stations associated to the access point with more hops away from the gateway are given higher transmit opportunity, and therefore the spatial bias problem in multi-hop wireless network can be alleviate

Development of a Desktop Freehand 3-D Surface Reconstruction System

This paper discusses the development of a freehand 3-D surface reconstruction system. The system was constructed by making use of readily available off-the-shelf components, namely a laser line emitter and a webcam. The 3-D laser scanner system allows the user to hand sweep the laser line across the object to be scanned. The 3-D surface information of the object is captured as follows. A series of digital images ofthe laser line, generated by the intersection of the laser plane, the surface of the object and the background planar object were captured and stored in a PC. The points on the laser line were extracted. The 2D laser points that were found on the surface of the planar object were projected onto the 3-D space using a pinhole camera model. The laser plane was calibrated. Using the 2-D laser points found on the surface of the 3-D object, a cloud of 3-D points which represent the surface of the object being scanned was generated by triangulation. For the laser plane calibration two different methods were implemented. Their performance were compared

A REVIEW OF MULTIHOP BASED MEDIUM ACCESS CONTROL (MAC) PROTOCOL TO TACKLE BOTH MULTIPLE ACCESS AND MULTIHOP ISSUES IN WIRELESS MESH NETWORK (WMN)

Multihop WMN plays an important role in the next-generation wireless communication. It promised a solution to provide ubiquitous wireless access at low cost and with architecture that easy to be deployed and maintained. A big challenge in designing WMN is to utilize the shared medium, the wireless communication channel, effectively. MAC protocol, the shared medium access controller, therefore plays a critical role in the channel utilization. The better the channel is utilized in WMN, the better is the performance of the WMN. One of the techniques to improve channel utilization is by enabling the concurrent transmission and providing an efficient forwarding operation. However, the existing IEEE 802.11 MAC does not supports those operations in WMN thus degrades the throughput significantly. To date, various multihop based MAC protocols was developed and proposed by researchers with the aim to regulate and solve access issues among all radio nodes in the network. This article presents an exhaustive survey of multihop based contention MAC protocols that proposed to solve exposed node and forwarding issues in multihop WMN. Besides that, the comparison, their operations, advantages and disadvantages of all identified MAC protocols also will be explained and presented in this article

Evaluation of Image Pixels Similarity Measurement Algorithm Accelerated on GPU with OpenACC

OpenACC is a directive based parallel programming library that allows for the easy acceleration of existing C, C++ and Fortran based applications with minimal code modifications. By annotating the bottleneck causing a section of the code with OpenACC directives, the acceleration of the code can be simplified, leading for high portability of performance across different target Graphic Processing Units (GPUs). In this work, the portability of an implemented parallelizable chi-square based pixel similarity measurement algorithm has been evaluated on two consumer and professional grade GPUs. To our best knowledge, this is the first performance evaluation report that utilizes the OpenACC optimization clauses (collapse and tile) on different GPUs to process a less workload (low resolution image of 581x429 pixels) and a heavy workload (high resolution image of 4500 x 3500 pixels) to demonstrate the effectiveness and high portability of OpenACC

A Smooth Forwarding Operation in Wireless Mesh Network

The IEEE 802.11 Distributed Coordination Function (DCF) Medium Access Control (MAC) protocol is designed to efficiently facilitate the limited communication bandwidth of wireless channel. This protocol uses Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) mechanism. This mechanism continues suffer from throughput degradation when directly applied in multihop Wireless Mesh Network (WMN). The major reason for this poor performance is due to larger signaling overheads (RTS and CTS signaling packet) introduced in order to forward a single data packet in multihop WMN. This inefficient forwarding operation caused the throughput degradation signifficantly. Therefore, an efficient forwarding operation is proposed in this paper to reduce the amount of signaling overheads which are needed to forward a single packet in multihop WMN. The proposed protocol uses the capability of overhearing in order to forward the data packet from one hop to another hop. This process will continue until the data packet reaches the respective destination. As a result, the enhanced protocol reduces the latency caused by signaling thus improve its throughput in multihop WMN. The multihop network performances are evaluated analytically in terms of throughput and delay. Through the simulation, it is proven that the proposed protocol provides significant improvement in throughput and delay. The results show that the proposed protocol outperforms the existing IEEE DCF MAC protocol when it is evaluated in multihop WMN

A SURVEY OF CONTENTION BASED MEDIUM ACCESS CONTROL (MAC) PROTOCOLS IN WIRELESS LAN

In wireless network, all radio nodes are tuned to the same frequency to interconnect and establish communication between each other. All nodes in the network broadcasts their packets over a common medium and in such scenario collisions are considered as instinctive attribute. Therefore, a proper method/regulation known as Medium Access Control (MAC) protocol is required to regulate and manage an efficient access to the common channel. The protocol is designed to allow radio nodes in wireless network to broadcast their packets in an orderly and efficient manner to eliminate the collision among them. It also provides a fair bandwidth sharing to all contending nodes in the network. To date, various MAC protocols was developed to regulate the communication access among all radio nodes in wireless network. This article presents an exhaustive survey of existing contention based MAC protocols, their operations, advantages and disadvantages. Other than that, a typical MAC protocol used in IEEE 802.11 wireless networks standard, such as Carrier Sense Multiple Access (CSMA) and Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) also explained and presented in this article

Evaluation on the Effect of EEG Pre-processing and Hyper parameters Tuning to the Performance of Convolutional Neural Network Motor Execution Classification

Electroencephalogram (EEG) based classification has achieved a promising performance using deep learning models like Convolutional Neural Network. Various pre-processing strategies such as smoothing the EEG data or filtering are commonly used to pre-process the captured EEG signal before the subsequent feature extraction and classification while hyperparameters tuning might help to improve the classification performance. As well, the number of layers used in the CNN can affect the performance of the classification. In this paper, the number of layers needed for the CNN to classify the EEG data correctly, the effect of apply smoothing to pre-process the EEG signal for modern end-to-end CNN and the effect of enabling hyperparameters tuning during the training phase of CNN is investigated and analyzed. Two CNN models, namely Deep CNN with 5 layers and Shallow CNN with 1 layer, with convincing classification accuracy on motor execution classification as reported in the literature were chosen for this study. Both the CNN models are trained on EEG motor execution dataset with different training strategies and dataset pre-processing. Based on the obtained training and test classification accuracy, Shallow CNN trained with enabling hyper parameters tuning and without smoothing the EEG data achieved the best classification accuracy with average training accuracy of 99.9% and test accuracy of 96.87%. This indicates that CNN does not need to have many layers to correctly classify the motor execution data and the EEG data does not require smoothing

Wi-Fi Sniffer Based Commuters Statistics Collection System For Reliable Bus Scheduling System

Traffic congestion issues have always been a concern for the fast growing metropolitans in which more than 90 percent of trips are made entirely by private means of transportation i.e. by car and motorcycle. As the country is actively engaged in infrastructure development especially in the transportation network to facilitate the movements of people and goods, a high demand for better public transportation is needed to reduce the issue of road congestion (percentage of GDI lost due to man hour lost in the traffic). Therefore, a cost effective Wi-Fi sniffing based bus commuters’ statistic collection system is designed and developed to study the feasibility of predicting the necessity of scheduling additional bus services when the detected number of Wi-Fi enabled devices exceeded the bus capacity. The developed system is subsequently deployed to the busiest university bus stop and the obtained result shows that variation of sniffed MAC address exhibit parallelism to the actual number of commuters waiting at the bus station as observed in the captured bus station video images. Result also shows that the MAC address based counting system can help to alert the bus management for better scheduling when the commuter at the particular bus stop is traveling to the same destination