Multi-Output Gaussian Processes for Crowdsourced Traffic Data Imputation

Traffic speed data imputation is a fundamental challenge for data-driven transport analysis. In recent years, with the ubiquity of GPS-enabled devices and the widespread use of crowdsourcing alternatives for the collection of traffic data, transportation professionals increasingly look to such user-generated data for many analysis, planning, and decision support applications. However, due to the mechanics of the data collection process, crowdsourced traffic data such as probe-vehicle data is highly prone to missing observations, making accurate imputation crucial for the success of any application that makes use of that type of data. In this article, we propose the use of multi-output Gaussian processes (GPs) to model the complex spatial and temporal patterns in crowdsourced traffic data. While the Bayesian nonparametric formalism of GPs allows us to model observation uncertainty, the multi-output extension based on convolution processes effectively enables us to capture complex spatial dependencies between nearby road segments. Using 6 months of crowdsourced traffic speed data or "probe vehicle data" for several locations in Copenhagen, the proposed approach is empirically shown to significantly outperform popular state-of-the-art imputation methods.Comment: 10 pages, IEEE Transactions on Intelligent Transportation Systems, 201

Perceived Economic Pressures and Farmer Ethics

We consider the effect of perceived economic pressures on the ethical attitudes of farmers. We hypothesize that an increase in the economic pressures a farmer faces could result in that farmer being more tolerant of unethical conduct than farmers not experiencing economic pressures. To test this hypothesis, we use data from a survey of 3,000 Missouri farmers with farm sales in excess of $10,000 in 2005 in which farmers were asked how acceptable they considered various unethical or questionable farming practices. The survey also contained questions designed to measure perceived economic pressures. We find evidence that economic pressures result in a greater willingness of farmers to tolerate unethical conduct, particularly in the case of actions that have the potential of causing harm or that are influenced by law or contract. We also find that the more frequently a farmer reports observing an unethical action, the more acceptable he is of it.Farm Management,

Systematics and Relationships of Fallugia (Rosoideae—Rosaceae)

The paper presents a systematic monograph of Fallugia (Rosoideae, Rosaceae) consisting of one variable species, Fallugia paradoxa. Morphological, cytological and molecular data clearly support its relationship with Geums.l. rather than Purshia-Cowani, with which it is often allied. The species was named twice independently in 1825 from the specimens and drawings, respectively, assembled by Sessé and Mociño for their proposed Flora Mexicana. The paper discusses the nomenclatural history, morphological variation, and the polygarno-dioecious mode of reproduction of the species. No infraspecific taxa are recognized

Comparative methods of cleaning meat cutting tables

Digitized 2007 AES.Includes bibliographical references (page 8)

Effect of Aging on Taut Rubber Diaphragms

As part of an investigation of special compositions of rubber suitable for use as diaphragms for aircraft instruments, six samples were used as taut diaphragms in instruments and allowed to age for five years. Two of the instruments were in operating condition after this period of time and one had remarkably little change in performance. In making the rubber tetraethyl thorium disulfide was employed as a vulcanizing agent

Dehydrated pork studies : removal of glucose by yeast fermentation

This bulletin reports research undertaken in cooperation with the Quarter-master Food and Container Institute for the Armed Forces, and has been assigned number 571 in the series of papers approved for publication...--P. [2].Digitized 2007 AES.Includes bibliographical references (page 12)

The Mighty Oak

I have a test I administer, in secret and in silence, to traveling companions along a stretch of road in southeast Nebraska. It is not a test of knowledge,or of character, but of timbre

New Species and Transfers into Justicia (Acanthaceae)

Justicia medrani and J. zopilotensis are described as new species while Anisacanthus gonzalezii is transferred into Justicia. The triad all have floral venation similar to red, tubular-flowered species of Justicia, though they differ from most Justicia in their tricolporate pollen with distinct pseudocolpi. In pollen and anther characters they are similar to Anisacanthus and Carlowrightia, but they differ from these in corolla vascularization and anther presentation and from Carlowrightia in corolla size. As the three taxa do not appear to represent a monophyletic group, and as Stearn has placed taxa with similar pollen into what has become a holding genus, Justicia, we include these in Justicia by default until further studies can decipher relationships within the genus

Microflora of prepackaged luncheon meats

Digitized 2007 AES.Includes bibliographical references (page 20)

Single Stranded DNA Translocation Through A Nanopore: A Master Equation Approach

We study voltage driven translocation of a single stranded (ss) DNA through a membrane channel. Our model, based on a master equation (ME) approach, investigates the probability density function (pdf) of the translocation times, and shows that it can be either double or mono-peaked, depending on the system parameters. We show that the most probable translocation time is proportional to the polymer length, and inversely proportional to the first or second power of the voltage, depending on the initial conditions. The model recovers experimental observations on hetro-polymers when using their properties inside the pore, such as stiffness and polymer-pore interaction.Comment: 7 pages submitted to PR