Nonlinear Phase Filtering Effects on GNSS Receiver Positioning Accuracy

This paper demonstrates nonlinear phase filtering effects on GNSS receiver accuracy. Using a nonlinear phase filter in a GNSS receiver can change the pseudorange estimation up to 250 metres which introduces an error in the overall positioning calculation. Paper shows the study of the nonlinear phase filtering effects on the pseudorange estimation and demonstrates how it can be compensated with minimal hardware usage.

From space immaterial: the invisibility of the lawscape

This article aims to interrogate law's ambivalent relationship with urban space. It deals with the paradoxical relation between law and the city, visibility and invisibility, materiality and abstraction, and polis and metropolis. It builds on previous work on the lawscape, namely the priority of invitation by law or the city to be conditioned by the other, and expands this line of thought towards a more tangible understanding of visibility and its mutual constitution with invisibility. We believe that spatialisation is a relevant avenue for law's (re)conceptualisation because it moves away from a description of humanism based on the universality of subjectivity, and paves the way for a particularised and material description of law's multiplicity that specifically addresses law's social positioning. This inevitably leads to a dematerialisation of space and the reinstatement of circularity between concreteness and abstraction. Inspired by some of the themes addressed by the contributors in this issue, we begin constructing a vocabulary of lawscaping, where law and urban space are brought together in an epistemological embrace that targets and eventually questions the solipsistic way in which the two of them have been conceptualised so far.

Survey techniques in urban freight transport studies

This article reviews and assesses the various survey techniques that have been used in studies in which data have been collected to obtain an understanding of road-based urban freight transport activities. The review identified 162 such studies in 18 countries over the last 50 years, and 12 different types of urban survey technique. In the studies reviewed, establishment surveys have been the most commonly used technique, followed by freight operator surveys, vehicle observation surveys, driver surveys, roadside interview surveys, and vehicle trip diaries. Few examples of other survey techniques (commodity flow, parking, global positioning system, supplier and service provider surveys) were identified. Establishment and vehicle observation surveys have the potential to offer insight into a wider range of issues associated with urban freight deliveries and collections to and from establishments in a specific urban area than the other survey techniques reviewed. These two survey techniques can provide insight into the frequency of goods vehicles deliveries and collections by time of day and day of week, the activities involved in the loading/unloading process, and the freight requirements of individual establishments. However, all 12 survey techniques provide insight into varying aspects of urban freight operations and various combinations are therefore likely to be used in future studies.

Modulation of a cytoskeletal calpain-like protein induces major transitions in trypanosome morphology

Individual eukaryotic microbes, such as the kinetoplastid parasite Trypanosoma brucei, have a defined size, shape, and form yet transition through life cycle stages, each having a distinct morphology. In questioning the structural processes involved in these transitions, we have identified a large calpain-like protein that contains numerous GM6 repeats (ClpGM6) involved in determining T. brucei cell shape, size, and form. ClpGM6 is a cytoskeletal protein located within the flagellum along the flagellar attachment zone (FAZ). Depletion of ClpGM6 in trypomastigote forms produces cells with long free flagella and a shorter FAZ, accompanied by repositioning of the basal body, the kinetoplast, Golgi, and flagellar pocket, reflecting an epimastigote-like morphology. Hence, major changes in microbial cell form can be achieved by simple modulation of one or a few proteins via coordinated association and positioning of membrane and cytoskeletal components.

A Comparative Study of a Low Doppler Shift in a Carrier Tracking Loop for GPS

This paper compares a carrier tracking scenario when a received Global Positioning System (GPS) signal has low Doppler frequency. It is shown that if the Numerically Controlled Oscillator (NCO) is quantized to 1 bit, the carrier tracking loop is unable to keep track of the incoming signal which leaves the tracking loop oscillating between the upper and lower bounds of the tracking loop bandwidth. One way of overcoming this problem is presented and compared with another existing solution, found in the literature, providing comparative results from the use of real-recorded off the air GPS L1 signals. Results show that the proposed method performs better tracking performance compared with the existing solution which it requires much less hardware complexity.