Which One is Correct, The Map or The GPS Trace

GPS data is noisy by nature. A typical location-based service would start by filtering out the noise from the raw GPS points that are generated by moving objects. Once the locations of the objects are identified, the location-based service is provided. In this paper, we decide not to throw away the noise. Instead, we consider the noise as an asset. We analyze the various noise patterns under different conditions and region characteristics. More specifically, we focus on one example where a lot of GPS noise is experienced; which is urban canyons. We believe that learning the GPS noise patterns in a supervised environment enables us to discover knowledge about new areas or areas where we have little knowledge. This paper is based on the analysis of GPS traces that are collected from the shuttle service within the Microsoft campuses around Seattle, Washington

Which One is Correct, The Map or The GPS Trace

GPS data is noisy by nature. A typical location-based service would start by filtering out the noise from the raw GPS points that are generated by moving objects. Once the locations of the objects are identified, the location-based service is provided. In this paper, we decide not to throw away the noise. Instead, we consider the noise as an asset. We analyze the various noise patterns under different conditions and region characteristics. More specifically, we focus on one example where a lot of GPS noise is experienced; which is urban canyons. We believe that learning the GPS noise patterns in a supervised environment enables us to discover knowledge about new areas or areas where we have little knowledge. This paper is based on the analysis of GPS traces that are collected from the shuttle service within the Microsoft campuses around Seattle, Washington

Noise Patterns in GPS Trajectories

As any other type of data, GPS traces contain noise, anomaly, and sometimes unexpected values. Normally, researchers and data engineers analysts would start dealing with GPS data by removing those noises and outliers. However, in this work, we take the opposite direction. We focus on analyzing those unexpected values rather than discarding them. Interestingly, we discovered useful findings from an insight look at the noise in GPS trajectories. The intuition behind those discoveries is that when unexpected GPS readings are observed several times around a specific location, we study the nature of that location rather than thrown away those reading. By doing so, we are able to tell the type of area around those readings. For example, we can infer that a driver is passing by a tall building or through a forest based on the pattern of noise in the GPS readings. We are also able to question the quality of the underlying road map. Our findings and discoveries are based on the analysis of real GPS data for the Microsoft shuttles

An Interactive Map-based System for Visually Exploring and Cleaning GPS Traces

It is a fact that there are tons of GPS traces generated every minute by the millions of in-road vehicles over the world. Naturally, those traces contain imprecise readings, and most of the time they include noise and outliers. Therefore, there is a real need for a tool to allow users, companies, and researchers to get a deep insight into those raw traces and discover potential knowledge out of it. This knowledge would uncover the quality level of the GPS traces and, indeed, the quality level of the underlying map. It would also help discover interesting facts about the surrounding environment such as the type and height of buildings, the landscape cover, the weather conditions, and the nature of businesses and activities. This demo presents a system that allows users to interactively explore their collected GPS traces. Users can visually inspect the precision of their raw GPS traces, and snap these traces to the underlying road network map. Furthermore, users have the ability to clean their traces by applying various types of spatio-temporal filters. Users can perform noise analysis and produce statistics over regions of interest on the map. Last but not least, the system gives suggestions or guesses on the surrounding environment by comparing the perceived noise patterns to a database of pre-stored noise patterns. For the demo purpose, the system is initially populated with a rich data set of trajectories generated from the Microsoft shuttle service around the Greater Area of Seattle

On the power of domain-specific hypertext environments

What is the potential power of hypertext technology? This article examines this question and outlines the answer by focussing attention to a domaim-specific view of hypertext environments. I first define what domain-specific hypertext environments (DSHE) represent. Next, I examine DSHE for the domains of encyclopedic and classical studies, creative writing and interactive fiction, journal and book publishing, insurance policy management, and software engineering. Then I describe in more detail the structure of information to evolve within a DSHE for software engineering in terms of document products, processing tasks and mechanisms, and workplace attributes. In turn, this examination provides the basis for identifying seven dimensions along which the power of DSHE can be defined, experienced, and accumulated. I also address the organizational costs that may be borne to realize this power. I conclude with observations as to the source of DSHE power as well as identifying topics for further investigation.

Design, Synthesis, and Antiviral Activity of α-Aminophosphonates Bearing a Benzothiophene Moiety

<div><p></p><p>A series of α-aminophosphonates containing a benzothiophene moiety was designed and synthesized. All synthesized compounds were confirmed by ¹H NMR, ¹³C NMR, ³¹P NMR, infrared spectroscopy, and elemental analysis. <i>The half-leaf method was used to determine the in vivo efficacy of</i> α-aminophosphonates bearing a benzothiophene moiety <i>against the tobacco mosaic virus (TMV). Bioassay results showed that all compounds exhibited certain anti-TMV activity at 500 μg/mL concentration. Compound <b>2f</b> exhibited a curative effect of up to 48.1%</i> against TMV, which was almost similar to that obtained from the standard ningnanmycin (51.9%).</p> <p>[Supplementary materials are available for this article. Go to the publisher's online edition of <i>Phosphorus, Sulfer, and Silicon and the Related Elements</i> for the following free supplemental files: Additional text, figures, and tables.]</p> </div

Correlation between negative life events and suicide attempts among Yi adolescents with HIV/AIDS in Liangshan Prefecture

Abstract Objective To investigate the incidence of suicide attempts among adolescents with HIV/AIDS in Liangshan Prefecture, Sichuan Province, as well as the correlation between negative life events, sleep, exercise, drug therapy and suicide attempts. Methods A total of 180 Yi adolescents aged 11–19 years with HIV/AIDS in a county of Liangshan Prefecture, Sichuan Province, China, were investigated by census. The main outcome indicators included the incidence of suicide attempts and whether negative life events, sleep, exercise, drug therapy and other factors were related to suicide attempts. Results We found that the incidence rate of suicide attempts among Yi adolescents with HIV/AIDS in Liangshan Prefecture was 13.9%. Negative life events were a risk factor for suicide attempts (OR = 1.047, p < 0.001, 95% CI 1.027–1.067). In the factors of negative life events, adaptation was a risk factor for suicide attempts (OR = 1.203, p = 0.026, 95% CI 1.022–1.416), and academic pressure showed a tendency to be a risk factor for suicide attempts (OR = 1.149, p = 0.077, 95% CI 0.985–1.339). However, the punishment factor, interpersonal stress factor and loss factor had no significant correlation with suicide attempts. There was no significant correlation between sleep, exercise, drug therapy and suicide attempts. Conclusion The proportion of suicide attempts among Yi adolescents with HIV/AIDS in Liangshan Prefecture is high and should be considered. Negative life events are independent risk factors for suicide attempts, and it is necessary to strengthen the screening and early intervention for suicide attempts in HIV/AIDS adolescents with definite negative life events