17,021 research outputs found
Managing contextual information in semantically-driven temporal information systems
Context-aware (CA) systems have demonstrated the provision of a robust solution for personalized information delivery in the current content-rich and dynamic information age we live in. They allow software agents to autonomously interact with users by modeling the userâs environment (e.g. profile, location, relevant public information etc.) as dynamically-evolving and interoperable contexts. There is a flurry of research activities in a wide spectrum at context-aware research areas such as managing the userâs profile, context acquisition from external environments, context storage, context representation and interpretation, context service delivery and matching of context attributes to usersâ queries etc. We propose SDCAS, a Semantic-Driven Context Aware System that facilitates public services recommendation to users at temporal location. This paper focuses on information management and service recommendation using semantic technologies, taking into account the challenges of relationship complexity in temporal and contextual information
Integrating fish resources to agro-ecosystem analyses
In October 2005, a consortium of partners led by the International Water Management Institute (IWMI) proposed a project aimed at integrating fish resources management in agricultural management in the Tonle Sap area. This 2-years project assistance was accepted for funding by the Challenge Program on Water and Food and started in January 2008. The overall goal of this project is to improve allocation and use of water in combined farming and fishing systems in order to enhance food security of rural communities and water productivity. The general objectives of the Fisheries component are: 1) to contribute to the review of existing fisheries and aquaculture information, assessment and data collection systems and existing databases from a fisheries perspective 2) to determine key questions that could be asked at the commune level that would enable the identification of fisheries issues for different agroecosystem zones. These would include both threats and potential threats to fisheries based on key ecological variables and opportunities that fisheries and aquaculture could represent in local livelihoods.Research, Lake fisheries, Agropisciculture, Ecosystems, Analysis, Cambodia, Tonle Sap L.,
Drinking patterns among Korean adults: results of the 2009 Korean community health survey.
ObjectivesIn Korea, the proportion of deaths due to alcohol is estimated at 8.9%, far exceeding the global estimate of 3.8%. Therefore, this study was performed to examine the factors associated with low-risk, moderate-risk, and high-risk drinking patterns in Korean adults and to identify target populations for prevention and control of alcohol-related diseases and deaths.MethodsWe analyzed data from 230 715 Korean adults aged 19 years and older who participated in the 2009 Korean Community Health Survey. Multinomial logistic regression analysis was used to examine associations between socio-demographic and health-related factors and patterns of alcohol use.ResultsA substantially larger proportion of men than women engaged in high risk (21.2% vs. 3.4%) and moderate-risk alcohol use (15.5% vs. 8.2%). In both sexes, moderate- and high-risk uses were associated with younger age, higher income, being currently employed, smoking, being overweight/obese, and good self-rated health.ConclusionsGiven the large proportion of the population that is engaging in moderate- and high-risk drinking and given the social norms that support this behavior, public health policies and campaigns to reduce alcohol consumption targeting the entire population are indicated
Reactively sputtered RuO2 diffusion barriers
The thermal stability of reactively sputtered RuO2 films is investigated from the point of view of their application as diffusion barriers in silicon contact metallizations with an Al overlayer. Backscattering spectra of Si/RuO2/Al samples and electrical measurements on shallow junction diodes with Si/TiSi2.3/RuO2/Al contacts both show that RuO2 films are effective diffusion barriers between Al and Si for 30-min annealing at temperatures as high as 600°C
Double Inverse Stochastic Resonance with Dynamic Synapses
We investigate the behavior of a model neuron that receives a
biophysically-realistic noisy post-synaptic current based on uncorrelated
spiking activity from a large number of afferents. We show that, with static
synapses, such noise can give rise to inverse stochastic resonance (ISR) as a
function of the presynaptic firing rate. We compare this to the case with
dynamic synapses that feature short-term synaptic plasticity, and show that the
interval of presynaptic firing rate over which ISR exists can be extended or
diminished. We consider both short-term depression and facilitation.
Interestingly, we find that a double inverse stochastic resonance (DISR), with
two distinct wells centered at different presynaptic firing rates, can appear.Comment: 12 pages, 7 figure
AGE DIFFERENCES AND MACROECONOMIC EFFECTS ON FOOD STAMP PROGRAM PARTICIPATION
Low income populations are more severely affected by economic downturns than their high income counterparts because they are at high risk of unemployment and face reduced earnings in recessions. The use of food stamp benefits and other types of welfare are one mechanism that families can use to buffer the economic shock brought about by income losses due to unemployment during a recession. As a result, during unfavorable economic conditions, low income households disproportionately rely on public assistance including food stamps. What is less understood are the differential effects of macroeconomic conditions on the participation propensities of different population subgroups. Of particular importance are differential effects by age. Depending on their age, poor workers are likely to experience different patterns of unemployment so that their welfare participation patterns also differ. For example, once older workers lose their jobs, their probability of re-employment is lower than that of their younger counterparts. The reduced expectations of re-employment coupled with fewer opportunities to invest in re-training are discouraging to older unemployed persons, often implying that job losses for older workers are permanent, and eventually lead to long term reliance on welfare programs. In contrast, younger poor workers have comparatively higher chances of re-employment and exit from welfare. Whether the age differences in welfare participation will remain unchanged during economic recessions as well is still unanswered. Understanding variations in FSP participation propensities across age groups and their dependency on macroeconomic conditions is essential to predict future demand for food stamp benefits and, by extension, other welfare programs. The continuing growth in FSP demand may point to unexpectedly large fiscal burdens for future taxpayers. Moreover, understanding differential effects of macroeconomic conditions on participation propensities for different groups will allow policy makers to better identify and eventually reach genuine needy families. Therefore, this study aims to investigate FSP participation patterns with a special emphasis on the differential impact of macroeconomic factors across several demographic groups with a particular focus on age cohort effects. Specifically, transitions into and out of FSP will be explicitly addressed using longitudinal data from the Survey of Income and Program Participation (SIPP) 2004 panel. To measure the impact of economic conditions, we match SIPP data with economic measures such as the unemployment rate and wages at the state level available from the Bureau of Labor Statistics. Using the data, monthly movements on and off of FSP of individuals is followed and categorized into entry sample and continuation sample. A household not participating in FSP in one month, and thus being part of the entry sample, can choose between entering or not entering FSP in the subsequent month. Similarly, a household enrolled in one month (and thus part of the continuation sample) can choose between either continuing to stay on FSP or exiting FSP in the next month. This gives rise to two types of transition models. The first model, referred to as the entry model, tackles the decision between entry versus non-entry into FSP, conditional on non-participation in the previous months. The second model, referred to as continuation model, addresses the decision between exiting from versus continuing FSP, conditional upon participation in the preceding month. Two transition models are estimated using probit technique while controlling for individual specific effects. This study finds several important results. First, there are significant age differences in entry into and exit from the FSP. The propensity of entry into the FSP among younger people is higher than among older people while young cohorts are more prone to exiting FSP than the oldest cohort of retired or retirement-bound people. The implication for the elderly is that once receiving FSP benefits, they are very likely to continue the FSP. Their observed low FSP participation rates can thus primarily be attributed to FSP entry barriers. Second, rising unemployment boosts FSP entry propensities and lengthens FSP spells. Changes in wage levels, however, affect neither entry nor exit propensities. Third, the effect of unemployment on FSP continuation propensities varies by age. The youngest cohort responds to increasing unemployment by drastically prolonging their FSP spells whereas the older extend their FSP spells more gradually. For the oldest cohort, FSP exit probabilities are even found to rise in association with rising unemployment, a phenomenon that can be explained by retirement and special transfer programs for the elderly.Food Stamp Program, Age, Macroeconomy, Transition, Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety, I38, J64,
WxN1âx alloys as diffusion barriers between Al and Si
Reactively sputtered tungsten nitride (WxN1âx) layers are investigated as diffusion barriers between Al overlayers and Si shallow n + -p junctions. Both amorphous W80 N20 and polycrystalline W60 N40 films were found to be very effective in preserving the integrity of the n + -p diodes for 30-min vacuum annealing up to 575 °C. Diode failure at higher temperatures is caused by localized penetration of Al into through the WxN1âx barriers. The effectiveness of the barrier decreases for polycrystalline W90 N10 and is worse for pure W
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Speed or deliberation: a comparison of post-disaster recovery in Japan, Turkey, and Chile
This paper compares recovery in the wake of three recent earthquakes: the Great East Japan Earthquake in March 2011; the Van earthquake in Turkey in October 2011; and the Maule earthquake in Chile in February 2010. The authors visited all three locations approximately 12-18 months after the incidents and interviewed earthquake specialists, disaster managers, urban planners, and local authorities. A key challenge to post-disaster recovery planning is balancing speed and deliberation. While affected communities must rebuild as quickly as possible, they must also seek to maximise the opportunities for improvement that disasters provide. The three case studies bring this dilemma into stark relief, as recovery was respectively slow, fast, and just right in the aftermath of the events: the Government of Japan adopted a deliberate approach to recovery and reconstruction; speed was of the essence in Turkey; and an effective balance between speed and deliberation was achieved in Chile
Gravitational energy in a small region for the modified Einstein and Landau-Lifshitz pseudotensors
The purpose of the classical Einstein and Landau-Lifshitz pseudotensors is
for determining the gravitational energy. Neither of them can guarantee a
positive energy in holonomic frames. In the small sphere approximation, it has
been required that the quasilocal expression for the gravitational
energy-momentum density should be proportional to the Bel-Robinson tensor
. However, we propose a new tensor
which is the sum of certain tensors
and , it has certain properties
so that it gives the same gravitational "energy-momentum" content as
does. Moreover, we show that a modified Einstein
pseudotensor turns out to be one of the Chen-Nester quasilocal expressions,
while the modified Landau-Lifshitz pseudotensor becomes the Papapetrou
pseudotensor; these two modified pseudotensors have positive gravitational
energy in a small region.Comment:
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