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RISS 인기검색어
- 검색키워드
- 저자 : Cuvelier, C. (검색결과 2 건)
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THE IMPACT OF POLICE LEVELS ON CRIME RATES
Hyeyoung Lim,Hoon Lee,Steven J. Cuvelier 아시아경찰학회 2010 Asia Pacific Journal of Police & Criminal Justice Vol.8 No.1
This article investigated whether increased policing levels reduce crime rates, focusing on methodological and statistical specifications which should be addressed to examine the relationship. A total of 256 findings out of 58 relevant studies were systematically analyzed. Although the types of crime rates used in each study varied, most of the findings produced negative relationships rather than positive ones between police levels and crime rates regardless of their significance levels. The overall results of this study, however, could not support firm conclusions on the deterrent impact of increased police levels on crime rates because most reviewed studies did not control essential variables and failed to resolve methodological issues in their analysis. A better specified and sophisticated research design and statistical techniques are needed to identify the relationship between police levels and crime.
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The influence of foreign vs. North American emissions on surface ozone in the US
Reidmiller, D. R.,Fiore, A. M.,Jaffe, D. A.,Bergmann, D.,Cuvelier, C.,Dentener, F. J.,Duncan, B. N.,Folberth, G.,Gauss, M.,Gong, S.,Hess, P.,Jonson, J. E.,Keating, T.,Lupu, A.,Marmer, E.,Park, R.,Schu Copernicus GmbH 2009 Atmospheric Chemistry and Physics Vol.9 No.14
<P>Abstract. As part of the Hemispheric Transport of Air Pollution (HTAP; http:// www.htap.org) project, we analyze results from 15 global and 1 hemispheric chemical transport models and compare these to Clean Air Status and Trends Network (CASTNet) observations in the United States (US) for 2001. Using the policy-relevant maximum daily 8-h average ozone (MDA8 O3) statistic, the multi-model ensemble represents the observations well (mean r2=0.57, ensemble bias = +4.1 ppbv for all US regions and all seasons) despite a wide range in the individual model results. Correlations are strongest in the northeastern US during spring and fall (r2=0.68); and weakest in the midwestern US in summer (r2=0.46). However, large positive mean biases exist during summer for all eastern US regions, ranging from 10-20 ppbv, and a smaller negative bias is present in the western US during spring (~3 ppbv). In nearly all other regions and seasons, the biases of the model ensemble simulations are ≤5 ppbv. Sensitivity simulations in which anthropogenic O3-precursor emissions (NOx + NMVOC + CO + aerosols) were decreased by 20% in four source regions: East Asia (EA), South Asia (SA), Europe (EU) and North America (NA) show that the greatest response of MDA8 O3 to the summed foreign emissions reductions occurs during spring in the West (0.9 ppbv reduction due to 20% emissions reductions from EA + SA + EU). East Asia is the largest contributor to MDA8 O3 at all ranges of the O3 distribution for most regions (typically ~0.45 ppbv) followed closely by Europe. The exception is in the northeastern US where emissions reductions in EU had a slightly greater influence than EA emissions, particularly in the middle of the MDA8 O3 distribution (response of ~0.35 ppbv between 35-55 ppbv). EA and EU influences are both far greater (about 4x) than that from SA in all regions and seasons. In all regions and seasons O3-precursor emissions reductions of 20% in the NA source region decrease MDA8 O3 the most - by a factor of 2 to nearly 10 relative to foreign emissions reductions. The O3 response to anthropogenic NA emissions is greatest in the eastern US during summer at the high end of the O3 distribution (5-6 ppbv for 20% reductions). While the impact of foreign emissions on surface O3 in the US is not negligible - and is of increasing concern given the recent growth in Asian emissions - domestic emissions reductions remain a far more effective means of decreasing MDA8 O3 values, particularly those above 75 ppb (the current US standard). </P>
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