Critical analysis and error determination of locating-finding techniques in GSM.

GPS is a well-established technique for location-finding, but mobile phone-based methods are generally less expensive to implement, and can give reasonable accuracies. These techniques can thus be useful to network operators in providing services based on geographical locations, and also to users. This paper reviews the main handset location techniques used within a GSM network, and critically appraises them. The main techniques covered include Cell-ID, E-CGI, TDOA, AOA, TOA, OTA and Timing Advance (TA). It also outlines a practical experiment in the UK in locating finding, which uses TA signal to locate the handset. The results show how an experiment can be conducted to determine the error in the location measurement

WiFiPoz -- an accurate indoor positioning system

Location based services are becoming an important part of life. Wide adoption of GPS in mobile devices combined with cellular networks has practically solved the problem of outdoor localization needs. The problem of locating an indoor user has being studied only recently. Much research contributed to the innovative concept of an indoor positioning system. By analyzing different technologies and algorithms, this thesis concluded that, considering a trade-off between accuracy and cost, a Wi-Fi based Fingerprint method is proved to be the most promising approach to determine the location of a mobile device. However, the Fingerprint method works in two phases-an offline training phase (collection of Received Signal Strength signatures) and an online phase in which data from the first phase is used to determine the current position of a mobile user. The number of training points in a certain area has a direct impact on the accuracy of the system. As a result, the offline phase is a tedious and cumbersome process and the positioning systems are only as accurate as the offline training phase has been detailed. Moreover, the offline phase must be repeated every time a change in the environment occurs. To avoid these limitations, we focus on improving the accuracy of the indoor positioning system, without increasing the number of training points. This thesis presents a Wi-Fi based system for locating a user inside a building. The system is named WiFiPoz, which means Wi-Fi positioning system based on the zoning method. WiFiPoz has a novel approach to Fingerprint method that incorporates Propagation and zoning methods. Experimental results show that WiFiPoz is highly efficient both in accuracy and costs. Compared to traditional Fingerprint methods, with the optimization of the accuracy of the location estimation, WiFiPoz reduces the number of training points. This feature makes it possible to quickly adapt to changes in the environment. In order to explore another possible solution, this thesis also developed, implemented and tested an indoor positioning system named GIS (Geometric Information based positioning System), which is based on a model proposed by another researcher. Several experiments were run in the offline phase and results were compared between the traditional Fingerprint method, GIS and proposed WiFiPoz. We concluded that WiFiPoz is a more efficient and simple way to increase the accuracy of the location determination with fewer training points --Document

Smart FRP Composite Sandwich Bridge Decks in Cold Regions

INE/AUTC 12.0

CSM-428: Techniques used for Location-based Services: A Survey

Not availabl

A survey on wireless indoor localization from the device perspective

With the marvelous development of wireless techniques and ubiquitous deployment of wireless systems indoors, myriad indoor location-based services (ILBSs) have permeated into numerous aspects of modern life. The most fundamental functionality is to pinpoint the location of the target via wireless devices. According to how wireless devices interact with the target, wireless indoor localization schemes roughly fall into two categories: device based and device free. In device-based localization, a wireless device (e.g., a smartphone) is attached to the target and computes its location through cooperation with other deployed wireless devices. In device-free localization, the target carries no wireless devices, while the wireless infrastructure deployed in the environment determines the target’s location by analyzing its impact on wireless signals. This article is intended to offer a comprehensive state-of-the-art survey on wireless indoor localization from the device perspective. In this survey, we review the recent advances in both modes by elaborating on the underlying wireless modalities, basic localization principles, and data fusion techniques, with special emphasis on emerging trends in (1) leveraging smartphones to integrate wireless and sensor capabilities and extend to the social context for device-based localization, and (2) extracting specific wireless features to trigger novel human-centric device-free localization. We comprehensively compare each scheme in terms of accuracy, cost, scalability, and energy efficiency. Furthermore, we take a first look at intrinsic technical challenges in both categories and identify several open research issues associated with these new challenges.</jats:p

Radio Frequency Interference Impact Assessment on Global Navigation Satellite Systems

The Institute for the Protection and Security of the Citizen of the EC Joint Research Centre (IPSC-JRC) has been mandated to perform a study on the Radio Frequency (RF) threat against telecommunications and ICT control systems. This study is divided into two parts. The rst part concerns the assessment of high energy radio frequency (HERF) threats, where the focus is on the generation of electromagnetic pulses (EMP), the development of corresponding devices and the possible impact on ICT and power distribution systems. The second part of the study concerns radio frequency interference (RFI) with regard to global navigation satellite systems (GNSS). This document contributes to the second part and contains a detailed literature study disclosing the weaknesses of GNSS systems. Whereas the HERF analysis only concerns intentional interference issues, this study on GNSS also takes into account unintentional interference, enlarging the spectrum of plausible interference scenarios.JRC.DG.G.6-Security technology assessmen

Occupancy Detection using Wireless Sensor Network in Indoor Environment

Occupancy detection plays an important role in many smart buildings such as reducing building energy usage by controlling heating, ventilation and air conditioning (HVAC) systems, monitoring systems and managing lighting systems, tracking people in hospitals for medical issues, advertising to people in malls, and to search and rescue missions. The global positioning system (GPS) is used most widely as a localization system but highly inaccurate for indoor applications. The indoor environment is difficult to handle because along with the loss of signals, privacy is a major concern. Indoor tracking has many aspects in common with sensor localization in Wireless Sensor Networks (WSN). The contribution of this work is the demonstration of a nonintrusive approach to detect an occupancy in a building using wireless sensor networks to detect energy from cell phones in a secure facility and perform indoor localization based on the minimum mean square error (MMSE). To estimate the occupancy, the detected cellular signals information such as signal amplitude, frequency, power and detection time is sent to a fusion server, matched the detected signals by time and channel information, performed localization to estimate a location, and finally estimated the occupancy of rooms in a building from the estimated locations

Development of Reaction Discovery Tools in Photochemistry and Condensed Phases

Photochemistry obeys different rules than ground-state chemistry and by doing so opens avenues for synthesis and materials properties. However, the different rules of photochemistry make understanding the fine details of photochemical reactions difficult. Computational chemistry can provide the details for understanding photochemical reactions, but the field of computational photochemistry is still new, and many techniques developed for ground-state reactions are not directly applicable to photochemical reactions. As a result, many photochemical mechanisms are not understood, and this hinders the rational design and synthesis of new photochemistry. To address this need, this thesis develops techniques to search for and study photochemical reactions. Chapter 2 and 3 develop methods to calculate photochemical reactions in gas- and condensed-phases via minimum energy reaction paths. First, Chapter 2 develops a method to search the molecular 3N-6 space for photochemical reactions. This space, although vast, is not chaotic and can be efficiently searched using a concept familiar to chemists: breaking and adding bonds and driving angles and torsions. Furthermore, this procedure can be automated to predict new chemistry not previously identified by experiments. Chapter 3 furthers this research by leveraging the concept of molecules to enable the computational study of reactions in large multi-molecular systems like crystals. Specifically, the use of a new coordinate system involving translational and rotational coordinates allows decoupling of the coordinate systems of the individual molecules, which is necessary for the efficient algebra. Importantly, these methods are general, they can be used to study single molecules and crystals, and much in between. These methods are demonstrated on complex chemical problems including the isomerization pathways of ethylene and stilbene (Chapter 2), the photocycloaddition of butadiene (Chapter 2), the rotation of a crystalline gyroscope (Chapter 3), the bicycle pedal rotation of cis,cis-diphenylbutadiene (Chapter 4), and the mechanism of a reversible photoacid (Chapter 5). These problems have value in understanding the processes of vision, optomechanics, and high-energy materials, and through their xx study much needed insight is gained that can be useful for designing new syntheses and materials. Furthermore, the new computational methods open the possibility for many future investigations. The results of Chapter 2 find a novel roaming-atom and hula-twist isomerization pathway and use automated reaction discovery tools to identify a missing butadiene photoproduct and why the [4+2] cycloaddition is forbidden. The results of Chapter 3 and 4 build on Chapter 2 by including the influence of a steric environment. Chapter 3 demonstrates by application to a molecular gyroscope that extreme long-range correlated motion can be captured with GSM, and Chapter 4 details how the one-bond flip and hula-twist mechanisms are suppressed by the crystal cavity, the nature of the seam space in steric environments, and the features of the bicycle pedal mechanism. For example, the bicycle pedals rotate through the passageway in the adjacent monomers. However, the models do not capture the quantitative activation barriers and more work is needed. Finally, Chapter 5 provides the ultrafast details of how the photoacid isomerizes and ring-closes with experimental and computational evidence. Unfortunately, quantitative calculation of pKa cannot be provided with the computations employed herein. In summary, this thesis provides an advancement in the knowledge of photochemical mechanisms that can be used for the development of new syntheses and offers new tools with capacity to study complex photochemical problems.PHDChemistryUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/163005/1/craldaz_1.pd

Novel Pitch Detection Algorithm With Application to Speech Coding

This thesis introduces a novel method for accurate pitch detection and speech segmentation, named Multi-feature, Autocorrelation (ACR) and Wavelet Technique (MAWT). MAWT uses feature extraction, and ACR applied on Linear Predictive Coding (LPC) residuals, with a wavelet-based refinement step. MAWT opens the way for a unique approach to modeling: although speech is divided into segments, the success of voicing decisions is not crucial. Experiments demonstrate the superiority of MAWT in pitch period detection accuracy over existing methods, and illustrate its advantages for speech segmentation. These advantages are more pronounced for gain-varying and transitional speech, and under noisy conditions