Non-scattering wavenumbers and far field invisibility for a finite set of incident/scattering directions

We investigate a time harmonic acoustic scattering problem by a penetrable inclusion with compact support embedded in the free space. We consider cases where an observer can produce incident plane waves and measure the far field pattern of the resulting scattered field only in a finite set of directions. In this context, we say that a wavenumber is a non-scattering wavenumber if the associated relative scattering matrix has a non trivial kernel. Under certain assumptions on the physical coefficients of the inclusion, we show that the non-scattering wavenumbers form a (possibly empty) discrete set. Then, in a second step, for a given real wavenumber and a given domain D, we present a constructive technique to prove that there exist inclusions supported in D for which the corresponding relative scattering matrix is null. These inclusions have the important property to be impossible to detect from far field measurements. The approach leads to a numerical algorithm which is described at the end of the paper and which allows to provide examples of (approximated) invisible inclusions.Comment: 20 pages, 7 figure

Assessing The "Value" Of New Transport Initiatives In Deprived Neighbourhoods In The UK

Since 1996, there has been growing policy awareness in the UK of the links between transport and social exclusion. Research by the government’s Social Exclusion Unit (SEU) has highlighted the fact that transport problems are often a major barrier to accessing work, healthcare, educational and other key facilities and has, therefore, become an increasingly important policy objective in moving people from welfare into work, addressing health inequalities, improving poor educational attainment and more generally promoting social exclusion and neighbourhood renewal. The SEU study puts in place a cross-departmental strategy to address these issues through a new local framework entitled Accessibility Planning, which is to be delivered by local transport planning authorities and their partners through the next round of Local Transport Plans. However, there has been little, if any, qualitative or quantitative analysis and evaluation of the contribution of new transport interventions in deprived areas. As such very little is known about whether they are facilitating increased economic and social participation for the individuals who use them. It is equally unclear if they have any positive impact on the wider process of regeneration in the neighbourhoods they serve. Anecdotal evidence suggests that they are assisting transitions from welfare into work, as well facilitating other important activities, such as health visits, educational attendance and leisure and social activities. The current funding and subsidy arrangements for transport initiatives specifically designed to support social inclusion are minimal at best and often non-existent. This paper describes case study research of four different transport projects that were funded under the UK Department for Transport’s now obsolete Urban Bus Challenge Fund. It aims to qualitatively and quantitatively evaluate their value to passengers in terms of quality of life benefits and also to identify their wider value to the local practitioners charged with the regeneration of the deprived areas they serve. On the basis of this evidence study aims to offer recommendations to central and local government on how such initiatives can be better supported in the future. Its key objectives are: • To identify the changes in travel behaviour and accessibility that have been brought about through the introduction of transport interventions within deprived and disadvantaged communities; • To explore the perceptions of local people in relation to these new services and with the broader aim of identifying the impact of these on the quality of life of the people who use them; • To explore the views of local practitioners regarding the contribution of such projects to the wider process of neighbourhood renewal in these areas; • To offer recommendations to central and local government on how such schemes can be better supported in the context of policies for neighbourhood renewal and the new requirements for accessibility planning in the 2006 Local Transport Plans. The research is funded by the Joseph Rowntree Foundation, a UK-based poverty campaign organisation that aims to raise awareness of the needs of people living in poor neighbourhoods across the UK.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

Научные подходы к диагностике социо-эколого-экономической устойчивости приморских регионов

На основе научных подходов предложена методика, позволяющая опреде-лить уровень социо-эколого-экономической устойчивости приморских ре-гионов. На основе использования системы показателей, характеризующих уровень социо-эколого-экономической устойчивости региона, сформули-рованы и предложены основные направления реализации методики опре-деления интегрального показателя уровня устойчивости приморской территории в социальном, экономическом и экологическом развитии.Based on the scientific approaches proposed technique allows to deter-mine the level of social, ecological and economic sustainability of coastal re-gions. On the basis of a system of indicators characterizing the level of social, ecological and economic sustainability of the region, formulate and propose guidelines implementation methodology for determining the integral indicator of the sustainability of the coastal territory in the social, economic and envi-ronmental development

Петрологічні дослідження в Україні: досягнення останніх десятиліть та нагальні проблеми

Викладено основні досягнення за останні 30–35 років українських геологів, в першу чергу — наукових працівників ІГМР ім. М. П. Семененка НАН України в області петрології. Висвітлені такі проблеми: 1 — метаморфізм, співвідношення грануліто-гнейсових і граніт-зеленокам’яних терейнів; 2 — чарнокіти; 3 — гранітоутворення та гранітоїдні формації; 4 — анортозит-рапаківігранітна формація; 5 — лужні породи; 6 — коматиїти; 7 — санукітоїди; 8 — метасоматоз; 9 — породоутворювальні та акцесорні мінерали; 10 — формаційний аналіз, петрологія та стратиграфія докембрію; 11 — фанерозойський магматизм; 12 — магматизм морського та океанічного дна; 13 — деякі нагальні проблеми.Изложены основные достижения за последние 30–35 лет украинских геологов, в первую очередь — научных сотрудников ИГМР им. Н. П. Семененко НАН Украины в области петрологии. Освещены такие проблемы: 1 — метаморфизм, соотношение гранулито-гнейсовых и гранит-зеленокаменных террейнов; 2 — чарнокиты; 3 — гранитообразование и гранитоидные формации; 4 — анортозит-рапакивигранитная формация; 5 — щелочные породы; 6 — коматииты; 7 — санукитоиды; 8 — метасоматоз; 9 — породообразующие и акцессорные минералы; 10 — формационный анализ, петрология и стратиграфия докембрия; 11 — фанерозойский магматизм; 12 — магматизм морского и океанического дна; 13 — некоторые насущные проблемы.Main achievements of Ukrainian geologists for the recent 30–35 years have been stated. In the first place the scientific results of petrologists of M. P. Semenenko Institute of Geochemistry, Mineralogy and Ore Formation of NAS of Ukraine. The following problems have been elucidated: 1 — metamorphism; interrelation of granulite-gneissic and granite-greenstone terrains; 2 — charnokites; 3 — granite formation and granitoid formations; 4 — anorthosite-rapakivi-granite formation; 5 — alkaline rocks; 6 — komatiites; 7 — sanukitoids; 8 — metasomatosis; 9 — rock-forming and accessory minerals; 10 — formation analysis, petrology and Precambrian stratigraphy; 11 — Phanerozoic magmatism; 12 — magmatism of the sea and ocean bottom; 13 — some current problems