1,939 research outputs found
A constant travel time budget? In search for explanations for an increase in average travel time
Recent research suggests that during the past decades the average travel time of the Dutch population has probably increased. However, different datasources show different levels of increase. Possible causes of the increase in average travel time are presented here. Increased incomes have probablyresulted in an increase in both costs and benefits of travel. The increase in travel time may also be due to benefits having increased more rapidly than costs. Costs may even have decreased due to the increased comfort level of cars and increased opportunities offered to make double use of one's time(e.g. working in a train)
Позиціонування вугільної галузі у зовнішньому енергетичному балансі України
Здійснено формування зовнішнього енергетичного балансу з розрахунком показника чистого експорту. Виконано комплексну оцінку співвідношення обсягів виробництва та споживання вугілля в Україні. Виявлено невідповідність обсягів виробленого та спожитого вугілля та його акумуляцію в Україні. Обґрунтовано необхідність зменшення обсягів імпорту вугілля.
Ключові слова: виробництво, зовнішній баланс, імпорт, комплексна оцінка, споживання, формування, чистий експорт.Осуществлено формирование внешнего энергетического баланса с расчетом показателя чистого экспорта. Выполнена комплексная оценка соотношения объемов производства и потребления угля в Украине. Выявлены несоответствие объемов произведенного и потребленного угля и его аккумуляция в Украине. Обоснована необходимость уменьшения объемов импорта угля.
Ключевые слова: внешний баланс, импорт, комплексная оценка, потребление, производство, формирование, чистый экспорт.Under present-day conditions it is important to maximize the consumption of energy resources produced in Ukraine, in particular coal resources. It will contribute to solving several macroeconomic problems of Ukraine like raising the energy assurance level as a component of national security of Ukraine, improving the competitiveness of domestic enterprises and the trade balance of Ukraine.
At the present stage of development the most popular energy resources are oil and natural gas which is conditioned by their high heating and ecological characteristics. At the same time the reduction of these resources, irregularity of their deposits and other objective factors make for consumption of local energy resources, in particular coal resources. It is defined that foreign energy balance is an index system that shows the demand-consumption ratio of an energy resource in a given period of time inside the country.
A foreign energy balance model has been designed which includes calculation of the net export and makes it possible to clear up the modern tendencies that established in our country’s external economic relations of energy resources trade. It has been proved that the basic factor reducing the net export of energy resources is a great volume of imported natural gas though the trade balance of coal and peat operations is negative as well. A complex evaluation of production and consumption ratio of coal in Ukraine based on reduction coefficient to oil equivalent has been carried out which makes it possible to reveal the discrepancy between the volume of coal produced and the volume of coal consumed with its latter accumulation in Ukraine. The necessity of reducing the volume of coal import is proved.
Keywords: foreign energy balance, import, complex evaluation, consumption, production, formation, net export
On the relationship between travel time and travel distance of commuters. Reported versus network travel data in the Netherlands
This paper gives a detailed empirical analysis of the relationships between different indicators of costs of commuting trips by car: difference as the crow flies, shortest travel time according to route planner, corresponding travel distance, and reported travel time. Reported travel times are usually rounded in multiples of five minutes. This calls for special statistical techniques. Ignoring the phenomenon of rounding leads to biased estimation results for shorter distances. Rather surprisingly, the distance as the crow flies and the network distance appear to be slightly better proxies of the reported travel time compared with the shortest network travel time as indicated by the route planner. We conclude that where actual driving times are missing in commuting research the other three indicators mentioned may be used as proxies, but that the following problems may emerge: actual travel times may be considerably higher than network times generated by route planners, and the average speed of trips increases considerably with distance, implying an overestimate of travel time for long distance commuters. The only personal feature that contributes significantly to variations in reported travel times is gender: women appear to drive at lower average speeds according to our data. As indicated in the paper this may be explained by the differences in the car types of male and female drivers (females drive older and smaller cars) as well as higher numbers of stops/trip chaining among women. A concise analysis is carried out for carpoolers. Car-pooling leads to an increase in travel time of some 17% compared with solo drivers covering the same distance. In the case of car poolers, the above mentioned measures appear to be very poor proxies for the actual commuting times
Bereikbaarheid: perspectieven, indicatoren en toepassingen
In dit hoofdstuk geven we een overzicht van perspectieven op en indicatoren
voor bereikbaarheid. Doel ervan is duidelijk to maken dat voor zowel
onderzoek als beleid het van groot belang is goed aan to geven wat men
precies onder bereikbaarheid verstaat, en dat de juiste keuze van bereikbaarheidsindicatoren
voor zowel onderzoek als beleid van groot belang i
A method to evaluate equitable accessibility: combining ethical theories and accessibility-based approaches
In this paper, we present the case that traditional transport appraisal methods do not sufficiently capture the social dimensions of mobility and accessibility. However, understanding this is highly relevant for policymakers to understand the impacts of their transport decisions. These dimensions include the distribution of mobility and accessibility levels over particular areas or for specific population groups, as well as how this may affect various social outcomes, including their levels of participation, social inclusion and community cohesion. In response, we propose a method to assess the socially relevant accessibility impacts (SRAIs) of policies in some of these key dimensions. The method combines the use of underlying ethics principles, more specifically the theories of egalitarianism and sufficientarianism, in combination with accessibility-based analysis and the Lorenz curve and Gini index. We then demonstrate the method in a case study example. Our suggestion is that policymakers can use these ethical perspectives to determine the equity of their policies decisions and to set minimum standards for local transport delivery. This will help them to become more confident in the development and adoption of new decision frameworks that promote accessibility over mobility and which also disaggregate the costs and benefits of transport policies over particular areas or for specific under-served population groups
Survey for Transiting Extrasolar Planets in Stellar Systems. II. Spectrophotometry and Metallicities of Open Clusters
We present metallicity estimates for seven open clusters based on
spectrophotometric indices from moderate-resolution spectroscopy. Observations
of field giants of known metallicity provide a correlation between the
spectroscopic indices and the metallicity of open cluster giants. We use \chi^2
analysis to fit the relation of spectrophotometric indices to metallicity in
field giants. The resulting function allows an estimate of the target-cluster
giants' metallicities with an error in the method of \pm0.08 dex. We derive the
following metallicities for the seven open clusters: NGC 1245,
[m/H]=-0.14\pm0.04; NGC 2099, [m/H]=+0.05\pm0.05; NGC 2324, [m/H]=-0.06\pm0.04;
NGC 2539, [m/H]=-0.04\pm0.03; NGC 2682 (M67), [m/H]=-0.05\pm0.02; NGC 6705,
[m/H]=+0.14\pm0.08; NGC 6819, [m/H]=-0.07\pm0.12. These metallicity estimates
will be useful in planning future extra-solar planet transit searches since
planets may form more readily in metal-rich environments.Comment: 38 pages, including 12 figures. Accepted for publication in A
ENIGMA and global neuroscience: A decade of large-scale studies of the brain in health and disease across more than 40 countries
This review summarizes the last decade of work by the ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) Consortium, a global alliance of over 1400 scientists across 43 countries, studying the human brain in health and disease. Building on large-scale genetic studies that discovered the first robustly replicated genetic loci associated with brain metrics, ENIGMA has diversified into over 50 working groups (WGs), pooling worldwide data and expertise to answer fundamental questions in neuroscience, psychiatry, neurology, and genetics. Most ENIGMA WGs focus on specific psychiatric and neurological conditions, other WGs study normal variation due to sex and gender differences, or development and aging; still other WGs develop methodological pipelines and tools to facilitate harmonized analyses of "big data" (i.e., genetic and epigenetic data, multimodal MRI, and electroencephalography data). These international efforts have yielded the largest neuroimaging studies to date in schizophrenia, bipolar disorder, major depressive disorder, post-traumatic stress disorder, substance use disorders, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism spectrum disorders, epilepsy, and 22q11.2 deletion syndrome. More recent ENIGMA WGs have formed to study anxiety disorders, suicidal thoughts and behavior, sleep and insomnia, eating disorders, irritability, brain injury, antisocial personality and conduct disorder, and dissociative identity disorder. Here, we summarize the first decade of ENIGMA's activities and ongoing projects, and describe the successes and challenges encountered along the way. We highlight the advantages of collaborative large-scale coordinated data analyses for testing reproducibility and robustness of findings, offering the opportunity to identify brain systems involved in clinical syndromes across diverse samples and associated genetic, environmental, demographic, cognitive, and psychosocial factors
Brain multiplexes reveal morphological connectional biomarkers fingerprinting late brain dementia states
Accurate diagnosis of mild cognitive impairment (MCI) before conversion to Alzheimer\u27s disease (AD) is invaluable for patient treatment. Many works showed that MCI and AD affect functional and structural connections between brain regions as well as the shape of cortical regions. However, \u27shape connections\u27 between brain regions are rarely investigated -e.g., how morphological attributes such as cortical thickness and sulcal depth of a specific brain region change in relation to morphological attributes in other regions. To fill this gap, we unprecedentedly design morphological brain multiplexes for late MCI/AD classification. Specifically, we use structural T1-w MRI to define morphological brain networks, each quantifying similarity in morphology between different cortical regions for a specific cortical attribute. Then, we define a brain multiplex where each intra-layer represents the morphological connectivity network of a specific cortical attribute, and each inter-layer encodes the similarity between two consecutive intra-layers. A significant performance gain is achieved when using the multiplex architecture in comparison to other conventional network analysis architectures. We also leverage this architecture to discover morphological connectional biomarkers fingerprinting the difference between late MCI and AD stages, which included the right entorhinal cortex and right caudal middle frontal gyrus
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