Indoor pedestrian dead reckoning calibration by visual tracking and map information

Currently, Pedestrian Dead Reckoning (PDR) systems are becoming more attractive in market of indoor positioning. This is mainly due to the development of cheap and light Micro Electro-Mechanical Systems (MEMS) on smartphones and less requirement of additional infrastructures in indoor areas. However, it still faces the problem of drift accumulation and needs the support from external positioning systems. Vision-aided inertial navigation, as one possible solution to that problem, has become very popular in indoor localization with satisfied performance than individual PDR system. In the literature however, previous studies use fixed platform and the visual tracking uses feature-extraction-based methods. This paper instead contributes a distributed implementation of positioning system and uses deep learning for visual tracking. Meanwhile, as both inertial navigation and optical system can only provide relative positioning information, this paper contributes a method to integrate digital map with real geographical coordinates to supply absolute location. This hybrid system has been tested on two common operation systems of smartphones as iOS and Android, based on corresponded data collection apps respectively, in order to test the robustness of method. It also uses two different ways for calibration, by time synchronization of positions and heading calibration based on time steps. According to the results, localization information collected from both operation systems has been significantly improved after integrating with visual tracking data

Collective turnover : an expanded meta-analytic exploration and comparison

As evidenced by the publication of three meta-analyses in 2013, the importance of collective turnover is garnering increasing attention. Although each of these meta-analyses delivers a unique and significant impact to the HR literature, there remain opportunities to expand and build upon their contributions. In a comparison of the three extant meta-analyses, we found over 90 unique papers that were included in only one of each of the three studies, and > 10 new studies published since 2013. We combined and expanded the existing meta-analyses, offering a comparison of results, as well as contributing to a greater understanding of the role of collective turnover. In the most comprehensive analysis to date, analyzing 2149 effect sizes from 159 studies across 150 articles, we find both support for and divergence from several previously examined relationships, as well as evidence of a curvilinear turnover-performance relationship and of the contagious influence of turnover

Competition of reactive signals and thiol modifications of proteins

It is clear that cells are constantly bombarded by multiple signals, often initiating similar, or even conflicting, responses. Important players in this suite of signals are the reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), the reactive nitrogen species (RNS), such as nitric oxide (NO) and sulfur-based molecules, such as hydrogen sulfide (H2S). These compounds are often involved in stress responses and dysfunction of these signaling systems is often involved in disease [1-3]. This commentary discusses the interactions of such signals, which was discussed in a previous paper [3]. It was argued that all these molecules are not acting in the same manner, and that H2S was acting in a role which moderated the effects of ROS and NO

Degree-2 spherical harmonics of the Earth's gravity field from Earth rotation parameters and SLR measurements to LAGEOS

The gravity field of the Earth is fundamental to subjects such as geodesy and geophysics. Many observations within geodesy refer directly or indirectly to gravity. Geodetic techniques provide information regarding the Earth and the processes that act on it. Mass and angular momentum are, according to physics, conserved in a closed system. The Earth interacts very little with components outside of it and can be thought of as a closed system. Mass components in one reservoir of the Earth system are exchanged with others. Mass redistribution within the Earth system is caused by geophysical processes. This movement of geophysical fluid (mass) causes variations in the Earth’s rotation, gravity field and geocentre. The improvement of geodetic techniques over the last few decades allows us to measure the effects of these processes on the Earth to an unprecedented accuracy. Earth rotation parameters (ERPs) are excited by variations in the mass distribution on the Earth’s surface and the exchange of angular momentum between the atmosphere and oceans and the solid Earth. The same mass redistribution causes temporal changes in the gravity field coefficients with the second degree harmonics related to the rotational deformation and hence to changes in the Earth’s inertial tensor. If precise models of the atmospheric and oceanic angular momentum are available solution for polar motion and degree-2 Stokes harmonics can be unified. In this study we utilise SLR tracking of LAGEOS to compare (i) degree-2 harmonics from ERPs and gravitation, and (ii) LAGEOS excitation functions and geophysical data (mass + motion). To what extent a unified approach is possible with current models for AM data and gravity mass change estimated from ERP within orbit determinations is investigated. Finally, the ability of SLR to calculate the motion of the Earth’s geocentre is also investigated.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Own mechanism for solving disputes over retaining walls near property boundaries

Retaining walls can be an important and sometimes a necessary construction in subdivisions for maximising land use and dividing allotments both vertically and horizontally. When ownership of a retaining wall erected near a property boundary is unknown it can cause disputes to arise over which property owner should bear the burden of responsibility. There is minimal legislation available in Australia which relates to retaining walls on or near property boundaries and since most States do not consider a retaining wall to be a fence, it therefore cannot be covered by dividing fence legislation. The aim of this research is to conduct a review of the current Australian legislation relating to retaining walls and to create a mechanism which outlines possible solutions for overcoming disputes which may arise over retaining walls near property boundaries. Comparing and contrasting Australian legislation confirms that there is minimal information which can be used to create the own mechanism and therefore general land law, common land law, case law and legislation outside of Australia is also investigated. The key to understanding the current Australian legislation can be clearly seen from the outcomes of specific case studies and the observations derived from them. Results showed that if the ownership of a retaining wall is not known, the purpose of the retaining wall and who benefits from the retaining wall should then be considered. The own mechanism takes into account the answers to these two questions and produces possible solutions which aim to determine the ownership and responsibility of a retaining wall which is on or near a property boundary with the desired outcome being to overcome neighbouring disputes. The own mechanism is designed to produce possible outcomes without changing the current Australian legislation. It may not be possible to create solutions in which everybody is satisfied, however, procedures have been identified which work well within the current legislation and may minimise disputes which arise over retaining walls

Benefit of triple-frequency on cycle-slip detection

At the time of writing, all the Global Navigation Satellite Systems (GNSS) support or are designed to support triple- or multi- frequency, which is expected to have advantages over single- and dual- frequency. This paper will conduct research on how triple-frequency can benefit the cycle-slip detection process. Correctly detecting and repairing cycle slips can help extend the latency of the fixed ambiguities, estimate the ionospheric delay, reduce the measurement noise and finally improve the positioning precision of the carrier phase. This paper will firstly review the widely used cycle-slip detection methods, including high-order phase differencing, Doppler integration and the ionospheric residual. For applying triple-frequency in cycle-slip detection, we will modify the Hatch-Melbourne-Wübbena combination to eliminate the effect of the ionospheric bias and reduce the measurement noise on the detection value. The triple-frequency method can detect and correct cycle slips instantaneously. All the mentioned methods will be tested using triple-frequency Galileo data observed in static condition. The results show that the performance of the triple-frequency method has a higher success rate and a lower missed detection compared to those using single-frequency, especially in detecting small cycle slips in observation with large intervals. Although the ionospehric residual provides higher success rates at low elevation angles, the triple-frequency method is more advanced than the ionospheric residual, which cannot decide the magnitude of the cycle slips easily

A tightly-coupled GPS/INS/UWB cooperative positioning sensors system supported by V2I communication

This paper investigates a tightly-coupled Global Position System (GPS)/Ultra-Wideband (UWB)/Inertial Navigation System (INS) cooperative positioning scheme using a Robust Kalman Filter (RKF) supported by V2I communication. The scheme proposes a method that uses range measurements of UWB units transmitted among the terminals as augmentation inputs of the observations. The UWB range inputs are used to reform the GPS observation equations that consist of pseudo-range and Doppler measurements and the updated observation equation is processed in a tightly-coupled GPS/UWB/INS integrated positioning equation using an adaptive Robust Kalman Filter. The result of the trial conducted on the roof of the Nottingham Geospatial Institute (NGI) at the University of Nottingham shows that the integrated solution provides better accuracy and improves the availability of the system in GPS denied environments. RKF can eliminate the effects of gross errors. Additionally, the internal and external reliabilities of the system are enhanced when the UWB observables received from the moving terminals are involved in the positioning algorithm

The invasion of Greece in 1941 and the Nazi hordes that never were...

Includes image: 'landscape with three figures', 1935.AbstractDespite the significance of the German invasion of Greece in 1941 within the international history of the Second World War, relatively little research has yet been conducted into many of its operational aspects. As a consequence, over the last 70 years a number of serious misconceptions have developed and been used to explain (or explain-away) British defeat within this campaign. Foremost is the notion of a huge disparity in numbers - against which Commonwealth troops, despite their courage and stoic resolve, could never stand. This key explanation is mistaken. By no means and by no measure did overwhelming German numbers push Imperial troops unwillingly out of Greece

UWB/GNSS-based cooperative positioning method for V2X applications

Limited availability of GNSS signals in urban canyons is a challenge for the implementation of many positioning-based traffic safety applications, and V2X technology provides an alternative solution to resolve this problem. As a key communication component in V2X technology, Dedicated Short Range Communication (DSRC) not only allows vehicles to exchange their position, but also traffic safety related information such as real-time congestion, up-to-date accident details, speed limits, etc. This position and traffic information could underpin various traffic safety applications - for instance, lane departure warnings, potential collision avoidance, and traffic congestion warnings. By taking advantage of DSRC, a vehicle in a GNSS denied environment is able to calculate its position using the assistance of other vehicles with sufficient GNSS signals to fix their locations. The concept of cooperative positioning, which is also called collaborative positioning, has been proposed to achieve this goal

A non-destructive technique for health assessment of fire-damaged concrete elements using terrestrial laser scanning

Concrete structures are routinely monitored to detect changes in their characteristics in the field of engineering surveying and other disciplines such as structural and civil engineering. There is growing demand for the development of reliable Non-Destructive Testing (NDT) techniques for concrete structures in the assessment of the deteriorating condition of infrastructures or in an event of fire-damaged structures. In this paper, the feasibility of using Terrestrial Laser Scanning (TLS) technology for change detection and assessment of fire-damaged concrete has been investigated through measurements and analysis of laboratory size concrete specimens that underwent heating up to 1000°C. The TLS technique employed in detecting fire-damaged concrete involved modelling and analysis of the TLS intensity returns as well as RGB image analysis. The results obtained clearly demonstrate the feasibility of using TLS to detect fire-damaged concrete. Although the laser scanners used in the study have different wavelengths, the results obtained in both cases are promising for a detection technique of fire-damaged concrete structures