Anti-aliasing filterAn anti-aliasing filter (AAF) is a filter used before a signal sampler to restrict the bandwidth of a signal to satisfy the Nyquist–Shannon sampling theorem over the band of interest. Since the theorem states that unambiguous reconstruction of the signal from its samples is possible when the power of frequencies above the Nyquist frequency is zero, a brick wall filter is an idealized but impractical AAF. A practical AAF makes a trade off between reduced bandwidth and increased aliasing.
Transfer functionIn engineering, a transfer function (also known as system function or network function) of a system, sub-system, or component is a mathematical function that models the system's output for each possible input. They are widely used in electronic engineering tools like circuit simulators and control systems. In some simple cases, this function can be represented as two-dimensional graph of an independent scalar input versus the dependent scalar output, called a transfer curve or characteristic curve.
Neural oscillationNeural oscillations, or brainwaves, are rhythmic or repetitive patterns of neural activity in the central nervous system. Neural tissue can generate oscillatory activity in many ways, driven either by mechanisms within individual neurons or by interactions between neurons. In individual neurons, oscillations can appear either as oscillations in membrane potential or as rhythmic patterns of action potentials, which then produce oscillatory activation of post-synaptic neurons.
Brain-readingBrain-reading or thought identification uses the responses of multiple voxels in the brain evoked by stimulus then detected by fMRI in order to decode the original stimulus. Advances in research have made this possible by using human neuroimaging to decode a person's conscious experience based on non-invasive measurements of an individual's brain activity. Brain reading studies differ in the type of decoding (i.e. classification, identification and reconstruction) employed, the target (i.e.
Art criticismArt criticism is the discussion or evaluation of visual art. Art critics usually criticize art in the context of aesthetics or the theory of beauty. A goal of art criticism is the pursuit of a rational basis for art appreciation but it is questionable whether such criticism can transcend prevailing socio-political circumstances. The variety of artistic movements has resulted in a division of art criticism into different disciplines which may each use different criteria for their judgements.
Kernel methodIn machine learning, kernel machines are a class of algorithms for pattern analysis, whose best known member is the support-vector machine (SVM). These methods involve using linear classifiers to solve nonlinear problems. The general task of pattern analysis is to find and study general types of relations (for example clusters, rankings, principal components, correlations, classifications) in datasets.
Environmental artEnvironmental art is a range of artistic practices encompassing both historical approaches to nature in art and more recent ecological and politically motivated types of works. Environmental art has evolved away from formal concerns, for example monumental earthworks using earth as a sculptural material, towards a deeper relationship to systems, processes and phenomena in relationship to social concerns. Integrated social and ecological approaches developed as an ethical, restorative stance emerged in the 1990s.
State (polity)A state is a centralized political organization that imposes and enforces rules over a population within a territory. Definitions of a state are disputed. One widely used definition comes from the sociologist Max Weber: a "state" is a polity that maintains a monopoly on the legitimate use of violence, although other definitions are common. Absence of a state does not preclude the existence of a society, such as stateless societies like the Haudenosaunee Confederacy that "do not have either purely or even primarily political institutions or roles".
State socialismState socialism is a political and economic ideology within the socialist movement that advocates state ownership of the means of production. This is intended either as a temporary measure, or as a characteristic of socialism in the transition from the capitalist to the socialist mode of production or to a communist society. State socialism was first theorised by Ferdinand Lassalle. It advocates a planned economy controlled by the state in which all industries and natural resources are state-owned.
Apache SparkApache Spark is an open-source unified analytics engine for large-scale data processing. Spark provides an interface for programming clusters with implicit data parallelism and fault tolerance. Originally developed at the University of California, Berkeley's AMPLab, the Spark codebase was later donated to the Apache Software Foundation, which has maintained it since. Apache Spark has its architectural foundation in the resilient distributed dataset (RDD), a read-only multiset of data items distributed over a cluster of machines, that is maintained in a fault-tolerant way.
State capitalismState capitalism is an economic system in which the state undertakes business and commercial (i.e. for-profit) economic activity and where the means of production are nationalized as state-owned enterprises (including the processes of capital accumulation, centralized management and wage labor). The definition can also include the state dominance of corporatized government agencies (agencies organized along business-management practices) or of public companies such as publicly listed corporations in which the state has controlling shares.