Efficient MaxCount and threshold operators of moving objects

Calculating operators of continuously moving objects presents some unique challenges, especially when the operators involve aggregation or the concept of congestion, which happens when the number of moving objects in a changing or dynamic query space exceeds some threshold value. This paper presents the following six d-dimensional moving object operators: (1) MaxCount (or MinCount), which finds the Maximum (or Minimum) number of moving objects simultaneously present in the dynamic query space at any time during the query time interval. (2) CountRange, which finds a count of point objects whose trajectories intersect the dynamic query space during the query time interval. (3) ThresholdRange, which finds the set of time intervals during which the dynamic query space is congested. (4) ThresholdSum, which finds the total length of all the time intervals during which the dynamic query space is congested. (5) ThresholdCount, which finds the number of disjoint time intervals during which the dynamic query space is congested. And (6) ThresholdAverage, which finds the average length of time of all the time intervals when the dynamic query space is congested. For these operators separate algorithms are given to find only estimate or only precise values. Experimental results from more than 7,500 queries indicate that the estimation algorithms produce fast, efficient results with error under 5%

Temporal and spatial variability in speakers with Parkinson's Disease and Friedreich's Ataxia

Speech variability in groups of speakers with Parkinson's disease (PD) and with Friedreich's ataxia was compared with healthy controls. Speakers repeated the same phrase 20 times at one of two rates (fast or habitual). A non-linear analysis of variability was performed which used some of the principles behind the spatio-temporal index (STI). The STI usually employs variation in lip displacement over repetitions of the same utterance and a linear analysis of such signals is conducted to represent the combined variation in spatial and temporal control. When working with patients, audio measures (here we used speech energy) are preferred over kinematics ones as they are minimally disruptive to speech. Non-linear methods allow spatial variability to be estimated separately from temporal variability. The results are tentatively interpreted as showing that PD speakers were distinguished from healthy control speakers in spatial variability and ataxic speakers were distinguished from controls in temporal variability. These findings are consistent with the speech symptoms reported for these disorders. We conclude that the non-linear analysis using the speech energy measure is worth investigating further as it is potentially revealing of the differences underlying these two pathologies

Domestic distortions and international trade

Trade is affected not only by taxes and subsidies that affect producers and consumers of goods, but also, indirectly, by taxes and subsidies that affect nontraded goods or factors of production. The authors show how the Trade Restrictiveness Index (TRI) may be extended to incorporate these types of distortions. Again, the value of the TRI gives the equiproportionate change in the prices of traded goods, which would compensate for a given change in all distortions, both in traded and nontraded goods and in factor markets. The authors, who developed the theory of the TRI, show how to apply it in practice, drawing on a larger study by Anderson and Bannister of changes in Mexican agricultural policy between 1985 and 1989. Adapting the TRI to a partial equilibrium context allows existing estimates of key demand and supply elasticities to be incorporated into the Index; and the basic formula is adapted to take account of some special features of Mexican agricultural markets. The TRI shows a great increase in restrictiveness in 1986 and especially 1987, followed by major reductions in restrictiveness in 1988 and 1989. The cumulative effect: a 49.9 percent fall in trade restrictiveness over the four years. The major, although not the only, source of changes in trade restrictiveness were changes in producer subsidies, especially for maize. These trends are not captured by changes in indices for consumer and producer subsidy equivalents, which the authors also present. Indeed, in a number of years at least one of the ad hoc indices changed in the opposite direction to the change in the corresponding welfare-based index.Access to Markets,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Markets and Market Access,Environmental Economics&Policies,Economic Theory&Research

Application of a news quality monitoring methodology

This set of case studies has two main purposes Case studies illustrating the usefulness of the quality monitoring framework set out in chapter one of The Future of Quality News Journalism: a cross-continental analysis The material that is produced below is still under development and may be modified when the final draft is produced shortly. a) Introduction This set of case studies has two main purposes. First, to provide examples of how the quality monitoring framework outlined in chapter one might be applied to online news stories of quality mainstream news providers. Second, to provide some representative sample evidence of the quality of the hard news provision of some of the best of the mainstream news providers. This is intended to back up the case for their continuing importance that is made within the bonus chapter (available only online at: HTTP://CLOK.UCLAN.AC.UK/7824) There are several things that it is important to emphasise. First, as chapter one makes clear, the preferred means of quality assessment would be via the kind of expert/professional panels outlined and suggested there. This should enhance the rigour of the evaluative process in so far as several pairs of expert eyes are likely to pick up inconsistencies in the application of that process in a way that would not be possible for one. Given that such panels do not yet exist to apply it and that the purpose here is mainly illustrative, the evaluations have been made by the author alone. That means that they should be treated with greater caution than had they been panel produced, but providing that is remembered it does not detract from their illustrative value. For the purposes of transparency and the need to provide readers with enough information to help them cross-check the judgments for themselves if they so wish, concise sample reasons are provided at the end of each piece as to why the individual quality ratings have been arrive

Welfare vs. Market Access: The Implications of Tariff Structure for Tariff Reform

We show that the effects of tariff changes on welfare and import volume can be fully characterized by their effects on the generalized mean and variance of the tariff distribution. Using these tools, we derive new results for welfare- and market-access-improving tariff changes, which imply two 'cones of liberalization' in price space. Because welfare is negatively but import volume positively related to the generalized variance, the cones do not intersect, which poses a dilemma for trade policy reform. Finally, we show that generalized and trade-weighted moments are mutually proportional when the trade expenditure function is CES.

A new approach to evaluating trade policy

The authors introduce a new measure, the Trade Restrictiveness Index, to measure the restrictiveness of a system of trade protection. They propose an alternative to the commonly used ad hoc indexes of trade restrictiveness, such as the trade-weighted average tariff. That measure has no welfare-theoretic basis and can be highly misleading, in practice. For example, the complete exclusion of trade in a commodity would usually lower the index, because its trade weight would fall to zero. The authors show that their proposed index is soundly based in standard welfare economics. When trade is restricted by tariffs only, the Trade Restrictiveness Index equals the uniform tariff, which would be equivalent to the existing system of tariffs in the sense of yielding the same level of aggregate welfare. But tariffs have declined in importance in recent years as a means of restricting trade, so the measure must also be able to take account of quantitative restrictions on trade. Where quotas are the only form of restriction, this is easy: the Index equals the equiproportionate reduction in permitted import volumes that is welfare-equivalent to the initial structure of quotas. When both quotas and tariffs are present, the Index can be defined as the uniform tariff factor (one plus the uniform tariff) and uniform import reduction factor which would yield the same level of welfare as the initial system of trade restrictions. The authors show how this can be formulated, noting that if a single good is subject to both a binding quota and a tariff, it should be viewed as quota-constrained - the tariff serves merely to ensure that some of the rents accrue to the importing country. These theoretical derivations permit a major synthesis of the theory of protection and suggest how the results of computable general equilibrium models might be presented to make them internationally and intertemporally comparable. But in most cases such a model is not available and, even if it were, it would not be sufficiently disaggregated to deal with a complicated system of trade protection. So the authors present some empirical short-cuts that can be adopted for estimating changes in the Index. Chief among these is the assumption that the goods under consideration are separable from others in an appropriate general-equilibrium sense. This can provide a rigorous foundation for a form of partial-equilibrium analysis (the consideration of a subset of markets in an economy). They also show how the Trade Restrictiveness Index can be adapted to allow for different forms of rent sharing and for a country's ability to influence its terms of trade. Applying these empirical methods to exports of textiles and apparel from Hong Kong to the United States, the authors find that the protective system becomes more restrictive for both countries over the seven years considered (1982-88). Increased trade restrictiveness does not necessarily mean that quotas have been tightened. When there is economic growth, constant or even rising import quotas might still amount to a tightening of protection. Results based on the trade-weighted average of"tariff equivalents"(the gaps between Hong Kong and U.S. prices) diverge significantly from those of the Trade Restrictiveness Index. The two measures have opposite implications for the change in trade restrictiveness for two-thirds of the observations.Environmental Economics&Policies,Trade Policy,Transport and Trade Logistics,Economic Theory&Research,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT

Campus Art Museums in the 21st Century: A Conversation

In the summer of 2012, the authors of this study brought together a group of campus art museum directors and outside experts to 'think out loud' about the changes already occurring at campus museums and where new opportunities and roles may be emerging. We hope the resulting paper will further the field's larger, continuing exploration of its roles and potentials through dialogue, research, and experimentation -- an exploration that contributes to the continued healthy evolution of campus art museum practice