"Influence Sketching": Finding Influential Samples In Large-Scale Regressions

There is an especially strong need in modern large-scale data analysis to prioritize samples for manual inspection. For example, the inspection could target important mislabeled samples or key vulnerabilities exploitable by an adversarial attack. In order to solve the "needle in the haystack" problem of which samples to inspect, we develop a new scalable version of Cook's distance, a classical statistical technique for identifying samples which unusually strongly impact the fit of a regression model (and its downstream predictions). In order to scale this technique up to very large and high-dimensional datasets, we introduce a new algorithm which we call "influence sketching." Influence sketching embeds random projections within the influence computation; in particular, the influence score is calculated using the randomly projected pseudo-dataset from the post-convergence Generalized Linear Model (GLM). We validate that influence sketching can reliably and successfully discover influential samples by applying the technique to a malware detection dataset of over 2 million executable files, each represented with almost 100,000 features. For example, we find that randomly deleting approximately 10% of training samples reduces predictive accuracy only slightly from 99.47% to 99.45%, whereas deleting the same number of samples with high influence sketch scores reduces predictive accuracy all the way down to 90.24%. Moreover, we find that influential samples are especially likely to be mislabeled. In the case study, we manually inspect the most influential samples, and find that influence sketching pointed us to new, previously unidentified pieces of malware.Comment: fixed additional typo

NASA Integrated Space Communications Network

The NASA Integrated Network for Space Communications and Navigation (SCaN) has been in the definition phase since 2010. It is intended to integrate NASA s three existing network elements, i.e., the Space Network, Near Earth Network, and Deep Space Network, into a single network. In addition to the technical merits, the primary purpose of the Integrated Network is to achieve a level of operating cost efficiency significantly higher than it is today. Salient features of the Integrated Network include (a) a central system element that performs service management functions and user mission interfaces for service requests; (b) a set of common service execution equipment deployed at the all stations that provides return, forward, and radiometric data processing and delivery capabilities; (c) the network monitor and control operations for the entire integrated network are conducted remotely and centrally at a prime-shift site and rotating among three sites globally (a follow-the-sun approach); (d) the common network monitor and control software deployed at all three network elements that supports the follow-the-sun operations

Shifting the evaluative gaze: Community-based program evaluation in the homeless sector

Homelessness is a growing social issue that is a consequence of structural inequities and contributor to the development of health inequities. Community-based research (CBR) has been proposed as an effective research strategy for addressing health equities and promoting social justice through participatory processes. The purpose of this article is to examine the application of CBR principles and practices in the homeless sector and the implications for the production of knowledge and social change to address homelessness. Drawing on our experiences as researchers and service providers, we reflect on the significant successes and challenges associated with using CBR in the homelessness sector. In our discussion we emphasise insights, challenges and lessons learned from a community-university partnership that focused on an evaluation of a transitional shelter program in a large urban centre where housing is expensive and often unavailable.Keywords: Homelessness, housing, transitional housing, transitional shelter, program evaluation, community-based researc

Do Word Of Mouth And Advertising Messages On Social Networks Influence The Purchasing Behavior Of College Students?

Many online advertisers are exploring the use of Internet social networking to build brand awareness and loyalty. Social networking is particularly popular among the younger, 15-24 year- old generation, who is more computer savvy and spends more time on the Internet than adults. While this generation has substantial potential, they also represent a challenge to advertisers. This group is notoriously skeptical of being “advertised at.” They expect a more personal, interactive experience. The purpose of this research is to determine which types of social networks are used most by college students and what types of online marketing impact their purchasing choices. In carrying out this research, the following research questions were addressed: which social networks are used most by college students; do factors such as student and/or parent income, student age, classification, gender, marital status, or employment status influence use of social networks; do ads on social networks impact purchasing decisions; does advice from other users of social networks impact purchasing decisions; and do online games, scavenger hunts, and contests influence purchasing decisions? The research provides a better understanding of social network use and provides insight into effective online advertising to college students

Organisational studies in an era of educational reform

One social science base for educational administration proposed in the Baron and Taylor collection was organisation theory. In the event this expectation turned out to be over-optimistic. Organisation theory was much too contested and insufficiently pragmatic for the British taste. Major developments in this field occurred mainly in the USA. Nevertheless, the more general approach of organisational studies continues to enhance our understanding of schools where a ‘both-and’ perspective is adopted towards organisational dualities, particularly in the face of what we have provocatively termed ‘transformania’. The article explores the unintended consequences of relentless transformania through three examples of duality: organisation–institution, bureaucracy–professionality, and the culture of teaching–the culture of managerialism. Finally, it is suggested that a revival of an interest in the somewhat dormant theory of ambiguity would be timely

Developing research expertise in applied linguistics: capacity-building for today’s interdisciplinary challenges

This paper explores the ambiguous nature of applied linguistics as a field of enquiry, to contextualise the interpretation of data from an empirical study into how research expertise in applied linguistics is conceptualised, and how it develops during an academic’s career. Key findings from the study include the importance of being willing to work at the boundaries of one’s knowledge, the capacity to communicate one’s ideas effectively, and the role of a good quality research environment for developing knowledge, skills and confidence. It is proposed that these features fit well with the modern imperative of addressing the world’s major problems though a cross-disciplinary approach to research, putting applied linguists into a strong position to contribute to new research knowledg

Modelling the removal of an earth bund to maximise seawater ingress into a coastal wetland

Weed infestation is a critical management issue for maintaining the natural values of coastal wetlands across the world. Widespread use of herbicides to control weeds has resulted in environmental issues in the past and has led to the search for more natural control methods such as using saline water. This study investigates management options to restore the natural flow regimes between freshwater wetlands and seawater by removing a bund which was built to grow ponded pasture. The study was carried out in the Mungalla wetland in Queensland, which is an important Nywaigi aboriginal community asset for recreation, cultural and economic activities. The study used modelling and monitoring methods to (a) assess how effective the earth bund was in excluding seawater and (b) the extent to which seawater could enter the wetland without the bund. Eleven scenarios were investigated to estimate seawater ingress under different tide, onshore wind, low atmospheric pressure and sea level rise (SLR) conditions. Results show that removal of the bund reinstated periodic tidal ingress into the wetland. Seawater intrusion was also shown to increase when there were onshore winds and/or low atmospheric pressure associated with cyclones. The greatest impact was under future SLR, where large increases in the inundation frequency and extent are likely to cause a shift in the wetland vegetation towards native salt tolerant species. Findings of this study are useful for examining the potential impact of various management interventions that are being considered for wetland system repair. For example, the removal or height adjustment of tidal barriers, dredging of silted streams, removal of weeds from choked streams and reintroduction of tidal flows to control weed infestation, improve water quality and restore natural values to the wetlands

The effects of moderate alterations in adrenergic activity on acute appetite regulation in obese women: a randomised crossover trial

Background: Previous evidence has demonstrated that serum leptin is correlated with appetite in combination with, but not without, modest exercise. Aim: The present experiments investigated the effects of exogenous adrenaline and α/β adrenoceptor blockade in combination with moderate exercise on serum leptin concentrations, appetite/satiety sensations and subsequent food intake in obese women. Methods: A total of 10 obese women ((mean ± SEM), age: 50 (1.9) years, body mass index 36 (4.1) kg/m2, waist 104.8 (4.1) cm) participated in two separate, double-blind randomised experimental trials. Experiment 1: moderate exercise after α/β adrenergic blocker (labetalol, 100 mg orally) versus moderate exercise plus placebo; experiment 2: adrenaline infusion for 20 minutes versus saline infusion. Appetite/satiety and biochemistry were measured at baseline, pre- and immediately post-intervention, then 1 hour post-intervention (i.e., before dinner). Food intake was assessed via ad libitum buffet-style dinner. Results: No differences were found in appetite/satiety, subsequent food intake or serum leptin in any of the studies (experiment 1 or experiment 2). In experiment 1, blood glucose was higher (p < 0.01) and plasma free fatty acids lower (p = 0.04) versus placebo. In experiment 2, plasma free fatty acids (p < 0.05) increased after adrenaline versus saline infusion. Conclusions: Neither inhibition of exercise-induced adrenergic activity by combined α/β adrenergic blockade nor moderate increases in adrenergic activity induced by intravenous adrenaline infusion affected acute appetite regulation

KECK HIRES Spectroscopy of APM 08279+5255

With an optical R-band magnitude of 15.2, the recently discovered z=3.911 BAL quasar APM 08279+5255 is an exceptionally bright high redshift source. Its brightness has allowed us to acquire a high signal-to-noise ratio (~100), high resolution (~6 km/s) spectrum using the HIRES echelle spectrograph on the 10-m Keck I telescope. Given the quality of the data, these observations provide an unprecedented view of associated and intervening absorption systems. Here we announce the availability of this spectrum to the general astronomical community and present a brief analysis of some of its main features.Comment: 21 pages including 5 figures. Accepted for publication by PAS