865 research outputs found
Learning a Bias Correction for Lidar-only Motion Estimation
This paper presents a novel technique to correct for bias in a classical
estimator using a learning approach. We apply a learned bias correction to a
lidar-only motion estimation pipeline. Our technique trains a Gaussian process
(GP) regression model using data with ground truth. The inputs to the model are
high-level features derived from the geometry of the point-clouds, and the
outputs are the predicted biases between poses computed by the estimator and
the ground truth. The predicted biases are applied as a correction to the poses
computed by the estimator.
Our technique is evaluated on over 50km of lidar data, which includes the
KITTI odometry benchmark and lidar datasets collected around the University of
Toronto campus. After applying the learned bias correction, we obtained
significant improvements to lidar odometry in all datasets tested. We achieved
around 10% reduction in errors on all datasets from an already accurate lidar
odometry algorithm, at the expense of only less than 1% increase in
computational cost at run-time.Comment: 15th Conference on Computer and Robot Vision (CRV 2018
Macroeconomic Modeling of Tax Policy: A Comparison of Current Methodologies
The macroeconomic effects of tax reform are a subject of significant discussion and controversy. In 2015, the House of Representatives adopted a new “dynamic scoring” rule requiring a point estimate within the budget window of the deficit effect due to the macroeconomic response to certain proposed tax legislation. The revenue estimates provided by the staff of the Joint Committee on Taxation (JCT) for major tax bills often play a critical role in Congressional deliberations and public discussion of those bills. The JCT has long had macroeconomic analytic capability, and in recent years, responding to Congress’ interest in macrodynamic estimates for purposes of scoring legislation, outside think tank groups — notably the Tax Policy Center and the Tax Foundation — have also developed macrodynamic estimation models. The May 2017 National Tax Association (NTA) Spring Symposium brought together the JCT with the Tax Foundation and the Tax Policy Center for a panel discussion regarding their respective macrodynamic estimating approaches. This paper reports on that discussion. Below each organization provides a general description of their macrodynamic modeling methodology and answers five questions posed by the convening authors
Mecamylamine pretreatment increases subsequent nicotine self-administration as indicated by changes in plasma nicotine level
Acute administration of mecamylamine, a centrally active nicotinic cholinergic agonist, has been shown to increase amount of smoking as indicated by smoking topography (e.g., puff rate, puff duration), expired carbon monoxide changes, and other inferential measures. In the present study, subjects showed significantly greater increases in plasma nicotine following smoking of two high-nicotine research cigarettes when pretreated with mecamylamine than when pretreated with placebo, even though no significant differences in puff volume or puff number were detected. Interestingly, none of our subjects reported nausea, although some achieved plasma nicotine levels at which nausea would typically be expected. We attribute the observed increases in nicotine intake to compensatory behavior designed to overcome mecamylamine's blocking effects.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46446/1/213_2004_Article_BF00518198.pd
Research on stress and smoking: progress and problems
Despite evidence that smoking behaviour increases in the context of stress, there has yet to be a clear-cut demonstration that nicotine intake is similarly enhanced. Although nicotine intake has been shown to reduce reported anxiety in the context of stress, the controlling conditions (type of stressor, intensity, temporal relationships, etc.) need further exploration. Recent findings involving nicotine's effects on the hypophyseal-adrenal axis provide a new perspective on these issues, in that increased nicotine intake during exposure to a stressor may represent, at least in part, behavioral compensation for diminished sensitivity to nicotine brought about by nicotine-stimulated corticosteroid release. Corticosteroids may decrease central nervous system excitability in a way that could account for anxiety reduction; on the other hand, anxiety reduction may be an epiphenomenon with respect to the reinforcement of smoking behaviour. The integration of behavioural, physiological, and biochemical research exemplified by the above approach should lead to a better understanding of stress and smoking.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73317/1/j.1360-0443.1991.tb01815.x.pd
Access to water in the countries of the former Soviet Union.
BACKGROUND: During the Soviet period, authorities in the USSR invested heavily in collective farming and modernization of living conditions in rural areas. However, many problems remained, including poor access to many basic amenities such as water. Since then, the situation is likely to have changed; economic decline has coincided with migration and widening social inequalities, potentially increasing disparities within and between countries. AIM: To examine access to water and sanitation and its determinants in urban and rural areas of eight former Soviet countries. METHODS: A series of nationally representative surveys in Armenia, Belarus, Georgia, Moldova, Kazakhstan, Kyrgyzstan, Russia and Ukraine was undertaken in 2001, covering 18,428 individuals (aged 18+ years). RESULTS: The percentage of respondents living in rural areas varied between 27 and 59% among countries. There are wide urban-rural differences in access to amenities. Even in urban areas, only about 90% of respondents had access to cold running water in their home (60% in Kyrgyzstan). In rural areas, less than one-third had cold running water in their homes (44% in Russia, under 10% in Kyrgyzstan and Moldova). Between one-third and one-half of rural respondents in some countries (such as Belarus, Kazakhstan and Moldova) obtained their water from wells and similar sources. Access to hot running water inside the homes was an exception in rural households, reflecting the lack of modern heating methods in villages. Similarly, indoor access to toilets is common in urban areas but rare in rural areas. Access to all amenities was better in Russia compared with elsewhere in the region. Indoor access to cold water was significantly more common among rural residents living in apartments, and in settlements served by asphalt roads rather than dirt roads. People with more assets or income and living with other people were significantly more likely to have water on tap. In addition, people who had moved in more recently were more likely to have an indoor water supply. CONCLUSIONS: This was the largest single study of its kind undertaken in this region, and demonstrates that a significant number of people living in rural parts of the former Soviet Union do not have indoor access to running water and sanitation. There are significant variations among countries, with the worse situation in central Asia and the Caucasus, and the best situation in Russia. Access to water strongly correlates with socio-economic characteristics. These findings suggest a need for sustained investment in rebuilding basic infrastructure in the region, and monitoring the impact of living conditions on health
Learning and Matching Multi-View Descriptors for Registration of Point Clouds
Critical to the registration of point clouds is the establishment of a set of
accurate correspondences between points in 3D space. The correspondence problem
is generally addressed by the design of discriminative 3D local descriptors on
the one hand, and the development of robust matching strategies on the other
hand. In this work, we first propose a multi-view local descriptor, which is
learned from the images of multiple views, for the description of 3D keypoints.
Then, we develop a robust matching approach, aiming at rejecting outlier
matches based on the efficient inference via belief propagation on the defined
graphical model. We have demonstrated the boost of our approaches to
registration on the public scanning and multi-view stereo datasets. The
superior performance has been verified by the intensive comparisons against a
variety of descriptors and matching methods
Dietary beliefs in the Baltic republics.
OBJECTIVES: As beliefs and knowledge about the possible effects of foods on health can influence food behaviours, this study examined selected dietary beliefs in the Baltic countries and the association of beliefs related to salt intake and to types of fat with food behaviours. DESIGN: A cross-sectional study. SETTING: Data from three surveys conducted in Estonia, Latvia and Lithuania in the summer of 1997 were used to describe the prevalence of dietary beliefs in these countries and to investigate the association between beliefs and behaviours (using logistic regression). SUBJECTS: Representative national samples of adults were selected in each country (Estonia, n = 2018; Latvia, n = 2308; Lithuania, n = 2153). RESULTS: Misunderstood concepts (myths) related to dietary salt, types of fat, meat consumption and bread and potatoes were observed in high proportions of the population. Education level was an important correlate of beliefs related to salt intake and types of fat, people with a higher education level being more likely to be familiar with these issues. Correct beliefs were not consistently associated with healthier behaviours (e.g. less frequent use of salt at the table and use of non-animal fats for cooking), except for salt intake in Estonia. CONCLUSIONS: Several misunderstood dietary concepts (myths) are still prevalent in the Baltic countries. Correct beliefs related to salt intake and types of fat were not consistent predictors of healthier food behaviours. In-depth qualitative investigations are needed to better describe and understand dietary beliefs and attitudes in the Baltic countries, and to identify barriers to the adoption of healthy food habits
Controlled dosing of nicotine via an I ntranasal N icotine A erosol D elivery D evice (INADD)
The present report describes an I ntranasal N icotine A erosol D elivery D evice (INADD) employing an artist's airbrush as aerosolizer and precise, electromechanical control of spray duration. It was designed for the administration of controlled doses of nicotine in a laboratory setting and has been used successfully in over 30 smokers and nonsmokers of both genders. In the present study, nicotine was administered to 12 male smokers at three different doses (0.05 mg, 1.00 mg, and 2.00 mg), and at the same dose (1 mg) on three different occasions. The low dose produced a minimal change in plasma nicotine, while the high dose produced a peak increment of around 16 ng/ml. The medium dose reliably produced a peak increment of around 8–9 ng/ml on all three occasions. Nicotine in plasma showed a sharp rise followed by a slower decline, mimicking the pattern associated with cigarette smoking. Physiological and biochemical responses showed significant dose-response relationships. Subjective reports suggested that aerosol dosing was somewhat aversive, but it is unclear whether this effect is intrinsic to the method or due to other factors. The device described in this report answers the need for a safe and easy means of controlling nicotine dose. Moreover, since nicotine administration via aerosol is novel for both smokers and non-smokers, minimizing the contributions of behavioral tolerance and habituation to the dosing vehicle, it lends itself to the comparison of the pharmacological effects of nicotine between experienced and naive subjects.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46339/1/213_2005_Article_BF02247431.pd
Alcohol consumption in Estonia and Finland: Finbalt survey 1994-2006
<p>Abstract</p> <p>Background</p> <p>Alcohol consumption has been regarded as an important contributor to the high premature mortality rates. The objective of this paper was to provide an overview and comparison of alcohol consumption and its socio-demographic determinants among adults in Estonia and Finland.</p> <p>Methods</p> <p>The study was based on a 25-64-year-old subsample of nationally representative postal cross-sectional surveys conducted in Estonia (n = 10,340) and Finland (n = 19,672) during 1994-2006. Abstinence, frequency, and the amount of alcohol consumed were examined. Logistic regression models were used to test the socio-demographic differences in alcohol consumption at least once a week. The effect of socio-demographic factors on pure alcohol consumed per week was calculated using linear regression.</p> <p>Results</p> <p>The proportion of abstainers was 1.5 times higher among women than men in both countries. Throughout the study period, the amount of alcohol consumed per week increased for both genders in Estonia and for women in Finland, but was stable for men in Finland. In the final study year, medium risk amount of alcohol consumed per week was nearly 1.5 times higher among men in Estonia than in Finland, but about half that among women in Estonia than in Finland. Compared to ethnic majority in Estonia, alcohol consumption at least once a week was lower among men, but amount of pure alcohol drunk per week was higher among women of ethnic minority. In Finland, alcohol consumption at least once a week was more prevalent among women of ethnic minority, but the amount of pure alcohol drunk per week was lower for both gender groups of ethnic minority. Compared to married/cohabiting respondents, alcohol consumption at least once a week was less pronounced among single respondents in Finland, divorced or separated women in both countries, and widowed respondents in Estonia. Greater amount of alcohol consumed per week was more prevalent among single and divorced or separated respondents in Finland, but only among divorced or separated men in Estonia. Frequency of alcohol consumption was lower among less educated than higher educated respondents in Finland, but not in Estonia. The amount of consumed alcohol per week was higher among less educated men in Estonia, but lower among women with basic education in Finland.</p> <p>Conclusions</p> <p>Alcohol consumption has increased in Estonia and Finland. National alcohol policies should reflect findings of alcohol epidemiology in order to introduce measures that will reduce alcohol related harm in the population effectively.</p
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