An apparatus for controlling a cooling air flow, in particular a gas turbine cooling air flow, is for the control, specific to requirement, of a cooling air flow using low-maintenance. A control fluid flow is introduced into the cooling air flow in the region of the flow duct with a flow component transverse to the flow direction of the cooling air flow through the flow duct. As such, the flow rate of the cooling air flow is adjustable as a function of control parameters of the control fluid flow and/or other parameters.

The invention generally relates to a gas turbine and method for controlling cooling of a gas turbine.
An air-cooled gas turbine blade appliance is known from EP 0 768 448 A1. The rotor blades are inserted on rotatable carrier disks. Due to the hot air supplied for the operation of the gas turbine, temperature-sensitive regions of the gas turbine are also heated and can be subjected to damage by this. The rotor blades, which are inserted on the rotatable carrier disks driven by the hot air, are cooled by cooling air supplied from the carrier disk. For cooling purposes, cooling air supplied radially from the outside flows through the stationary guide blades. This is used, inter alia, for cooling carrier disk lateral spaces located between the rotor blades and the guide blades.
For feeding the cooling air to the carrier disk lateral spaces at the radially inner end of a guide blade, the guide blade has an opening through which the cooling air, which is led through an external cooling air supply duct, is fed. The discharge of the rest of the cooling air takes place, essentially, through a large number of small openings, so-called film cooling holes, in a so-called blade nose into the hot air flow, so that a cooling air film is formed on the outside of the gas turbine blade.
In the case of an unrestricted cooling air supply with the objective of maximum cooling, the efficiency of the gas turbine, which is essentially determined by the temperature of the hot gas introduced, is greatly reduced by the large quantities of cooling air supplied and the energy consumption of the gas turbine is essentially increased.
Control valves are inserted to combat this. In general, these are commercial valve shapes and are located radially outside on the guide blade or further upstream in the supply path of the cooling air, in the cooling air supply duct.
Although, on the one hand, this makes the valve easily accessible in order, for example, to carry out possible repairs or adjustments, it means, on the other hand, that only a simultaneous adjustment is possible of the pressure of the cooling air for the carrier disk lateral space and of the pressure of the cooling air which flows through the film cooling holes onto the blade nose. Where adjustment takes place to a very low cooling air pressure, this can easily lead to break-down of the cooling air film on the blade nose and, in consequence, there is no longer adequate cooling of the guide blade surface. If, on the other hand, the cooling air pressure is adjusted to be strong to produce an adequate cooling film, a powerful cooling air flow is produced in the hot air and this leads to a reduction in the power of the gas turbine and a high consumption of energy.
An object of the present invention is to provide a control of a cooling air flow. In the case of a gas turbine, in particular, an automatic gas turbine, adequate cooling of the carrier disk lateral space by a supply of cooling air should be reliably ensured independently of the operating conditions. Further, at the same time, a high gas turbine efficiency should be achieved.
This object is achieved by providing an appliance for controlling a gas turbine cooling air flow through a flow duct. In one embodiment, it includes, a control fluid flow which is introduced into the cooling air flow, in the region of the flow duct, with a flow component transverse to the flow direction of the cooling air flow through the flow duct. In one embodiment, it is possible to adjust the flow rate of the cooling air flow as a function of control parameters of the control fluid flow and/or by the introduction geometry of the control fluid flow into the cooling air flow and/or by the geometry of the flow duct.
This type of control is well suited for difficult access locations on machines or the like, which are also subjected to severe loads. The appliance operates almost independently of dirt or other environmental influences such as, for example, aggressive chemical attacks due to a corresponding cooling air flow. The control element is not subject to any wear and erosion-free switching is possible because of the contactless adjustment without, for example, electrical current or mechanical appliances. Such a control appliance therefore requires very little maintenance because the control of the cooling air flow takes place exclusively by way of a specially adjusted supply of a control fluid flow. In the case of a failure of the control system, the originally adjusted cooling air flow takes place at its basic setting in any event. Independently of the function of the control flow, the cooling air flow can be adjusted before the appliance is put into operation in such a way that it is sufficient for the desired function.
The control fluid flow intervenes in the flow behavior of the cooling air in such a way that it either accelerates or retards the flow, respectively increasing or lowering the flow rate. This essentially takes place by changes in the type of the active fluid flow in specified boundary or central regions of the cooling air flow in the flow duct. This is, in particular, also directed toward converting the flow from a laminar flow to a turbulent flow. The precondition is that the control fluid flow should have a flow component suitable for influencing the flow when flowing into the cooling air flow. This refers to a component of its main flow direction which is directed transverse to the flow direction of the cooling air flow through the flow duct. By this, the flow behavior of the cooling air flow is influenced in a predetermined manner.
The control fluid is advantageously air. It is also conceivable to supply to the active fluid a control fluid with a composition which is, to a certain extent, xe2x80x9cneutralxe2x80x9d with respect to the cooling air flow, such as an aqueous solution water.
The control fluid flow can, on the one hand, be adjusted in strength, or in its flow rate, and exerts, by this, a control influence on the cooling air flow. On the other hand, its introduction geometry, for example the angular position of the control fluid flow relative to the cooling air flow, or the arrangement of the control fluid flow relative to the cooling air flow, can be changed. Influence can also be effected by changing the geometry of the flow duct through which the cooling air flows. The possibilities mentioned for the control can be combined with one another, the flow rate or strength of the control fluid flow being adjusted after the installation of an appliance according to the invention in a machine. In the case of a fixed geometry, the control fluid flow is controlled by means of control parameters of the control fluid flow which, however, depend on the respectively selected geometry.
The flow rate of the cooling air flow can preferably be adjusted by adjusting the pressure of the control fluid flow. Stepless and very accurate adjustment of the control fluid flow can be achieved by this, which adjustment can be undertaken with little complexity. This appliance also requires very little maintenance because a control flow is flowing almost continuously so that the supply ducts of the control flow are kept free.
The flow rate of the control fluid is preferably small relative to the flow rate of the cooling air flow because, in this way, no changes are undertaken to the physical and chemical properties of the cooling air flow, for example pressure or temperature changes or changes to the chemical composition or to a cooling function. In the event of a failure of the control fluid flow, furthermore, the cooling air flow continues to be sufficient to satisfy the envisaged duties so that the system, in which the appliance is inserted for control purposes, is not subject to any essential disturbance due to the failure of the control system. The proportion of the control fluid flow which is introduced into the cooling air flow is, in total, preferably smaller than 50% and, in particular, smaller than 10% of the total flow. The overall flow resulting, which is composed of the control fluid flow and the cooling fluid flow, practically corresponds to the previously introduced cooling air flow.
A further advantage of the control of a large flow by a small flow is, in addition, the low energy usage which is necessary for this purpose, or the small consumption of control fluid flow.
In a special introduction geometry, the control fluid flow can be introduced radially into the cooling air flow in the flow duct, i.e. the control fluid flow is located centrally and at right angles, or at least with a flow component at right angles, to the flow duct. This achieves a non-uniform incident flow of cooling air. In this way, the flow is strongly swirled, the vortex strength depending on the control parameters of the control fluid flow. In this way, the cooling air flow rate is reduced more or less strongly. Given optimum adjustment of the introduction geometry and optimum control parameter values, the mass flow becomes minimal. Given specified introduction geometry, a continuous control of the cooling air flow from the normal value down to a minimum value can be undertaken by changing the control pressure.
In the case of different introduction geometry, the control fluid flow can be introduced in the manner of a secant into the cooling air flow through the flow duct, i.e. although the control flow continues to be located with at least a component at right angles to the cooling air flow direction, it is not arranged centrally, i.e. not at the maximum diameter of the flow duct, in the case of a cylindrical flow duct, but more or less laterally distant from it. Thus, the control fluid flow is introduced into the cooling air flow corresponding to a type of secant in the case of a cylindrical flow duct. This type of designation should not, however, be understood as a limitation to cylindrical flow ducts but can also be applied to other duct shapes. This special type of supply generates a swirl in the flow duct and, in particular, in the active fluid flow. This swirl stabilizes the cooling air flow and increases its flow rate. Depending on the control parameters of the control fluid flow, the flow rate correspondingly extends from that originally adjusted to a maximum value. The achievable values of the flow rate also depend greatly on the introduction geometry of the control fluid flow and the geometry of the flow duct in the case of both the tangential and the radial in-flow.
One geometry of the flow duct, which is advantageous in application, is that the flow duct has a nozzle and a downstream diffuser with a specified opening angle and that the control fluid flow can be introduced in a transition peripheral region between the nozzle and the diffuser. This configuration of the flow duct geometry permits very accurate control of the cooling air flow, which flows first through the nozzle and then through the diffuser, a very small control fluid flow, which is fed into the cooling air flow between the nozzle and the diffuser, being sufficient.
In the case of a radial arrangement of the introduction of the control fluid flow, as presented above, the control fluid flow is preferably introduced in the region of the beginning of the diffuser. The introduction of the control fluid flow achieves a non-uniform incident flow into the diffuser, by which the pressure recovery in the diffuser is reduced. A powerful supply of control fluid achieves almost complete disturbance of the incident flow so that, finally, the pressure recovery is almost completely prevented. In this way, the flow rate and the mass flow through the nozzle become minimal. If the control fluid flow fails, the originally adjusted flow of cooling air flows through the nozzle and the diffuser.
In the case of a tangential feed of the control fluid flow into the cooling air flow, the control fluid flow is preferably supplied to the central region of the nozzle. In this way, the swirl generated stabilizes the diffuser flow. The pressure recovery and the mass flow through the nozzle is increased. Introduction procedures which are located between an extreme secant-type inlet flow and a radial inlet flow are also possible. This provides less eddying and, in addition, a less powerful swirl, which again exerts and influences on the flow rate.
If the diffuser, through which flow occurs, has an opening angle of approximately 10xc2x0 and there is a ratio of approximately 1:3 between the inlet area of the nozzle and the outlet area of the diffuser, a control range of the individual throttling element, which includes nozzle and diffuser, of 70% to 100% of the undisturbed flow rate can be achieved in the case of a radial introduction of the control fluid flow. This very wide control range can be adjusted by changing the pressure of the control fluid flow.
If the diffuser, through which flow occurs, has an opening angle of approximately 30xc2x0 and there is a ratio of approximately 1:3 between the inlet area of the nozzle to outlet area of the diffuser, a diffuser is obtained which only generates a trivial pressure recovery. If, in this case, the control fluid flow is fed tangentially into the nozzle, the control range of the throttle element consisting of nozzle and diffuser reaches 100% to almost 140% of the unaffected flow rate of the cooling air flow during the control fluid pressure adjustment.
An extension of the control range of the throttle element can be achieved if a plurality of the appliances described above are connected in series or parallel, the cooling air flowing through the appliances. In this way, for example in the case of a series connection of throttle elements, a cooling air flow reduced in the case of radial incident flow to 70% of the undisturbed flow rate is again reduced in the case of flow through the second throttle element, by which it is possible to achieve a reduction of the undisturbed flow rate to approximately 50%. If the control flows fail, the originally adjusted undisturbed cooling air flowxe2x80x94as already mentioned abovexe2x80x94flows again. A cooling air flow is therefore present in every case of disturbance of the control appliance, which is very advantageous for cooling purposes or other gas controls for ensuring a certain basic supply in order to prevent destruction of installations, for example because of a failure of a cooling function.
The control fluid flow can, in particular, be a control gas flow. Even hot or aggressive gases can be safely controlled by the appliance proposed. Mechanical parts, which could for example be damaged by oxidative or corrosive attack and would, because of this, lose their function, arexe2x80x94in association with the control gas flowxe2x80x94unnecessary for achieving a continuous control of the active gas flow. In order to control a hot active gas flow in the case of a very small control gas flow, it is not absolutely necessary for the control gas flow to have the same temperature as the active gas. This facilitates the generation and the introduction of the control gas flow because no sort of temperature measurement has to take place.
In the case of the use of the control appliance in a gas turbine, for example, both gas flows can also, however, be taken from the same gas source, which is compressed in the gas turbine, it being unnecessary for them to have the same gas parameters, such as pressure and temperature.
Very good utilization of the advantages, mentioned above, of the control appliance is possible in a gas turbine. A gas turbine, having rotor blades inserted on carrier disks, having stationary guide blades arranged between the carrier disks, cooling air flowing through the guide blades from a radially outer region to a radially inner region. The gas turbine further includes, between the respective rotor blade and guide blades, a carrier disk lateral space to which at least part of the cooling air flowing through the guide blade can be supplied. It has particularly high requirements with respect to the endurance and the freedom from maintenance of a throttle appliance for the cooling air emerging into the carrier disk lateral space, as has already been shown in the introduction. There are, in addition, severe effects due to high working gas temperatures.
With respect to the gas turbine, the object is achieved by at least one guide blade having, at a radially inner end region, an appliance which influences the cooling air supply to the carrier disk lateral space.
Such a control appliance blocks a supply of air from the hot gas duct from entering the carrier disk lateral space, and therefore prevents damage. This is done by cooling air expelled from the control appliance, air also designated as xe2x80x9cblockage airxe2x80x9d, and by associated xe2x80x9cexcess pressurexe2x80x9d in the carrier disk lateral space relative to the hot gas duct. By such an appliance, the cooling air supply is controlled directly at the radially inner end region of the guide blade during the inward flow of the cooling air into the carrier disk lateral space, and not previously in the cooling air supply duct to the guide blade. A control arrangement in the cooling air supply duct to the guide blade influences, as shown above, not only the cooling air supply to the carrier disk lateral space but also the cooling air supply to film cooling holes at the blade nose which, in the case of very low cooling air pressures, can lead to undesirable film breakdowns and therefore overheating of the blade nose. Control at the radially inner end region, which also includes adjacent components of the guide blade, for example, permits the required cooling air quantity to be minimized, which leads to a higher efficiency of the gas turbine without influencing the gas pressure at the film cooling holes. By the appliance proposed, the cooling air supply can be individually matched to the special geometry of the blades and of the carrier disk lateral spaces.
A particular effectively controllable and low-maintenance appliance for influencing the cooling air supply to the carrier disk lateral space of a gas turbine is provided by a control appliance being attached at the radially inner end region of a guide blade, by which the cooling air supply to the carrier disk lateral space can be controlled by a control air flow, as has been presented above in various forms. An embodiment of the invention then represents, so to speak, a pneumatic or aerodynamic quantity control of the blockage air.
The magnitude of the cooling air supply to the carrier disk lateral space does not have to be determined from the outset as soon as the guide blade is installed in the gas turbine, but can be subsequently adjusted by the control air flow with respect to the desired flow behavior at the radially inner end region. This is therefore particularly advantageous because, during the manufacturing process, no guide blade appliance corresponds exactly to another one. In this way, the cooling air supply can be optimized and the cooling air requirement can be minimized retrospectively by easy alterations to the cooling air flow. In this way, excessive cooling air is avoided but, at the same time, reliable cooling of the carrier disk lateral space is ensured.
An independent and low-maintenance appliance for supplying the cooling air flow to the throttle element at the radially inner end region of a guide blade is provided by it being possible to supply the control air flow through a feed duct to the transition peripheral region between the nozzle and the diffuser, the feed duct being provided within the guide blade and having a control appliance at its outer end region for adjusting the control air pressure. In this way, the control air flow at the radially inner end region of a guide blade can be adjusted, so to speak, xe2x80x9cby remote controlxe2x80x9d without complex mechanical appliances being necessary for this purpose. The control air flow always keeps its own supply free from dirt and therefore permits a long life for the throttling appliance. The control takes place outside the inner radial end region of the guide blade, which is severely affected by high temperatures, and is therefore easily accessible for maintenance.
The function of the throttle appliance is, again, not impaired when it is subject to high temperature and it has a permanently high control rate. It can also be overloaded occasionally without damage, for example due to an excessively high pressure adjustment of the control air flow. The air flow then only impinges on the walls of the nozzle or the diffuser but cannot seriously damage them. In the case of failure of the control system, a basic flow of cooling air occurs in any event and this can be adjusted independently of the function of the control air flow before the gas turbine is put into operation. For example, this can be done by a predetermined size of the openings in the flow duct and a fixed adjustment of the cooling air flow, set in such a way that its flow is sufficient for the desired function. If the control air flow can be selected to be very small, the feed duct is also small and can therefore be easily accommodated within the guide blade. Outside the guide blade, it would interfere with the operation of the gas turbine and make control impossible.
A high level of continuity and a reliable supply of the control air flow can be ensured by the feed duct having an intermediate region between the control appliance, which is provided in its outer region, and the entry into the transition peripheral region between the nozzle and the diffuser, the intermediate regions being connected by appliances, which influence the cooling air supply, of a plurality of guide blades of a carrier disk. This intermediate region, which represents a type of reservoir for the control air flow, permits the supply of a constant control air flow even if, sometimes, small fluctuations occur in the supply of the control air or if the pressure changes. A connection between the intermediate spaces of different guide blades by a type of supply duct further stabilizes the control air pressure and, in addition, permits a reduction in the number of control appliances necessary for the control of the control air flow.
In addition, the intermediate region permits cooling of the material surrounding it and therefore also serves to reduce the temperature in the region of the radially inner end region of the guide blades.

Device and method for controlling a cooling air flow of a gas turbine


In order to accomplish aforementioned and other objects, a spark ignition timing control system, according to the present invention employs means for monitoring maximum pressure point in an engine revolution cycle, where the internal pressure in an engine cylinder becomes maximum for deriving period required for fully propagating combustion in the engine cylinder on the basis of angular difference between spark ignition initiating point and the maximum, pressure point. The means predicts concentration of one of fuels in a mixture fuel on the basis of the derived propagating period. The system compares the predicted concentration with an actually measured concentration of the relevant fuel by means of a sensor to detect failure of the sensor. When failure of the sensor is detected, fail-safe operation is performed by setting the concentration data at a predetermined fixed value.

The present invention relates generally to a spark ignition timing control system for an automotive internal combustion engine for adjusting spark advance magnitude for optimal engine performance. More specifically, the invention relates to a spark ignition timing control system specifically adapted for controlling spark ignition timing in engine operation combustioning a mixture fuel, in which more than one type fuels, such as gasoline and alcohol, having mutually different combustion characteristics.
It is recent trend in the automotive technology to seek for higher anti-polution performance for protecting or recover pure atmosphere. Particularly, in the automotive vehicle exhaust gas, significant reduction of polutant, such as No.sub.x, CO and so forth, is becoming more and more strong order for this purpose. As can be appreciated, from the past, various attempts have been made for purification of engine exhaust gas. Such attempts gain significant level of improvement in terms of anti-polution. However, in view of increasing of automotive vehicles, further purification of exhaust gas becomes strictly important.
From the past, it has been known in the automotive technologies that alcohol fuel may create much lesser polutant, such as NO.sub.x, CO and so forth, in comparison with petrol or gasoline. Since alcohol fuel can be industrially or artificially produced, hi-bride fuel engines have already been developed and put into the market in certain countries. Such hi-bride fuel engine utilizes a blended fuel of gasoline and alcohol. In such blended fuel, combustion characteristics of the fuel varies significantly depending upon gasoline/alcohol mixture ratio due to relatively low combustibility of alcohol. Therefore, in case of such blended fuel, fuel delivery amount in terms of an induction air flow rate, spark ignition timing and so forth need to be controlled adapting the blended fuel property.
As is well known, spark ignition timing controls are performed principally for seeking spark advance angle for best torque in view of optimization f engine output performance. Such MBT control is combined with knock control in which spark advance angle is adjusted for maintaining the engine in light-knock condition. For harmonizing both of the MBT and the knock control, Japanese Patent First (unexamined) Publication (Tokkai) Showa 61-14479 proposes spark ignition timing control for controlling spark advance angle with respect to respective of individual engine cylinders. Namely, in the proposed system, knocking resistance at each individual engine cylinder is experimentally checked. MBT control is then performed in view of a cylinder pressure data in an engine cylinder having the highest knocking resistance until unacceptable engine knocking is detected. When unacceptable engine knocking is detected at the aforementioned specific engine cylinder having the highest knocking resistance, then the engine cylinder having second highest knocking resistant is selected to use the cylinder pressure data thereof for MBT control. Such proposal may be effective for enabling advancing of spark advance in most of the engine cylinders at MBT point.
The aforementioned prior proposal may be only applicable for the spark ignition timing control in terms of homogeneous fuel, i.e. gasoline, engine. In case of blended fuel, the proposed procedure of spark advance control cannot be directly applied due to substantial variation of MBT points depending upon gasoline/alcohol blending ratio. Substantial variation of MBT points may not significantly affect for the spark ignition timing control performance as far as steady or stable engine operating condition is concerned since the spark advance angle can be gradually adjusted toward the MBT point by feedback control. However, on the other hand, in the engine transition state, such as accelerating and decelerating state of the engine, offset of spark advance angle from MBT will cause substantial degradation of spark ignition timing control performance. Namely, when the spark advance angle is set at far retard angle from MBT point, the engine output can be lowered than that can be obtained at MBT point, to cause lowering of engine acceleration performance during engine acceleration state. On the other hand, excess magnitude of spark advance in terms of MBT point will leads unacceptable engine knocking.
In view of such difficulty, Japanese Patent First Publication (Tokkai) Showa 61-85578 proposed setting of variable basic spark advance in terms of property of fuel to be combustioned. For this, a fuel sensor for detecting mixture ratio or concentration of one of individual fuels in the blended fuel to select one of a plurality of settings. In case of gasoline/alcohol blended fuel, since the fuel property changed substantially according to the concentration of alcohol versus gasoline, substantially large capacity of memory becomes necessary for pre-setting various basic spark advance with respect to all possible variation range of alcohol mixture ratio.
On the other hand, Japanese Utility Model First (unexamined) Publication (Jikkai) Showa 62-171198 discloses a spark ignition timing control system which is adapted for alcohol/gasoline mixture fuel. The shown system performs MBT control and knock control for optimizing the engine performance. As well, the shown system employs an alcohol sensor for monitoring alcohol concentration in the mixture fuel so that the spark ignition timing can be modified according to the concentration of the alcohol in the mixture fuel. Modification of the spark ignition timing depending upon alcohol concentration as monitored by the alcohol sensor.
In such a prior proposed spark ignition timing control system it is essential that the alcohol sensor for monitoring alcohol concentration operates accurately for significant influence of the alcohol concentration for the spark ignition timing. However, since the alcohol sensor is dipped into the fuel, it can subject corrosion or fatigue to cause failure during long time use. As set forth, failure of alcohol sensor may cause substantial problem in control of the spark ignition timing.

Spark ignition timing control system for internal combustion engine


An apparatus comprising means for: receiving an indication of a form factor of a device; selecting an audio component, in dependence on the receiving an indication of a form factor of the device and in dependence on an assigned location of a graphical user interface object associated with the audio component, wherein the graphical user interface object is assigned to at least a first display area when the device is in a first form factor and is assigned to the at least a first display area when the device is in a second form factor; controlling audio processing of audio associated with the selected audio component; and providing at least the processed audio for audio output by one or more loudspeakers.

Devices that can provide audio data to onboard or external loudspeakers are known. The audio data can correspond to an audio file, an audio stream, and/or a particular software application assigned to a particular display area of a display of the device.
Devices that can change form factor are also known, such as flexible foldable devices.


Apparatus and methods for heterosynaptic plasticity in a spiking neural network having multiple neurons configured to process sensory input. In one exemplary approach, a heterosynaptic plasticity mechanism is configured to select alternate plasticity rules when performing neuronal updates. The selection mechanism is adapted based on recent post-synaptic activity of neighboring neurons. When neighbor activity is low, a regular STDP update rule is effectuated. When neighbor activity is high, an alternate STDP update rule, configured to reduce probability of post-synaptic spike generation by the neuron associated with the update, is used. The heterosynaptic mechanism impedes that neuron to respond to (or learn) features within the sensory input that have been detected by neighboring neurons, thereby forcing the neuron to learn a different feature or feature set. The heterosynaptic methodology advantageously introduces competition among neighboring neurons, in order to increase receptive field diversity and improve feature detection capabilities of the network.

1. Field of the Invention
The present innovation relates generally to artificial neural networks and more particularly in one exemplary aspect to computer apparatus and methods for pulse-code neural network processing of sensory input.
2. Description of Related Art
Artificial spiking neural networks are frequently used to gain an understanding of biological neural networks, and for solving artificial intelligence problems. These networks typically employ a pulse-coded mechanism, which encodes information using timing of the pulses. Such pulses (also referred to as "spikes" or 'impulses') are short-lasting (typically on the order of 1-2 ms) discrete temporal events. Several exemplary embodiments of such encoding are described in a commonly owned and co-pending U.S. patent application Ser. No. 13/152,084 entitled APPARATUS AND METHODS FOR PULSE-CODE INVARIANT OBJECT RECOGNITION", filed Jun. 2, 2011, and U.S. patent application Ser. No. 13/152,119, Jun. 2, 2011, entitled "SENSORY INPUT PROCESSING APPARATUS AND METHODS", each incorporated herein by reference in its entirety.
A typical artificial spiking neural network, such as the network 100 shown for example in FIG. 1 herein, comprises a plurality of units (or nodes) 102, which correspond to neurons in a biological neural network. Any given unit 102 may receive input via connections 104, also referred to as communications channels, or synaptic connections. Any given unit 102 may further be connected to other units via connections 112, also referred to as communications channels, or synaptic connections. The units (e.g., the units 106 in FIG. 1) providing inputs to any given unit via for example connections 104, are commonly referred to as the pre-synaptic units, while the unit receiving the inputs (e.g., the units 102 in FIG. 1) is referred to as the post-synaptic unit. Furthermore, the post-synaptic unit of one unit layer (e.g. the units 102 in FIG. 1) can act as the pre-synaptic unit for the subsequent upper layer of units (not shown).
Each of the connections (104, 112 in FIG. 1) is assigned, inter alia, a connection efficacy (which in general refers to a magnitude and/or probability of influence of pre-synaptic spike to firing of a post-synaptic neuron, and may comprise for example a parameter such as synaptic weight, by which one or more state variables of post synaptic unit are changed). During operation of the pulse-code network (e.g., the network 100), synaptic weights are typically adjusted using a mechanism such as e.g., spike-timing dependent plasticity (STDP) in order to implement, among other things, learning by the network.
One such adaptation mechanism is illustrated with respect to FIGS. 2-3. Traces 200, 210 in FIG. 2 depict pre-synaptic input spike train (delivered for example via connection 104_1 in FIG. 1) and post synaptic output spike train (generated, for example, by the neuron 102_1 in FIG. 1), respectively.
Properties of the connections 104 (such as weights w) are typically adjusted based on relative timing between the pre-synaptic input (e.g., the pulses 202, 204, 206, 208 in FIG. 2) and post-synaptic output pulses (e.g., the pulses 214, 216, 218 in FIG. 2). One typical STDP weight adaptation rule is illustrated in FIG. 3, where the rule 300 depicts synaptic weight change Δw as a function of the time difference between the time of post-synaptic output generation and arrival of pre synaptic input Δt=tpost−tpre. In some implementations, synaptic connections (e.g., the connections 104 in FIG. 1) delivering pre-synaptic input prior to the generation of post-synaptic response are potentiated (as indicated by Δw>0 associated with the curve 302), while synaptic connections (e.g., the connections 104 in FIG. 1) delivering pre-synaptic input subsequent to the generation of post-synaptic response are depressed (as indicated by Δw<0 associated with the curve 304 in FIG. 3). By way of illustration, when the post-synaptic pulse 208 in FIG. 2 is generated: (i) connection associated with the pre-synaptic input 214 precedes the output pulse (indicated by the line denoted 224) and it is potentiated (Δw>0 in FIG. 3 and the weight is increased); and (ii) connections associated with the pre-synaptic input 216, 218 that follow are depressed (Δw<0 in FIG. 3 and the weights are decreased).
Neural networks, such as that illustrated in FIG. 1, are often utilized to process visual signals, such as spiking signals provided by retinal gangling cells (RGCs) of neuroretina and/or output interface of artificial retina. In these applications, neurons (e.g., the neurons 102 in FIG. 1) receive inputs (e.g. via connections 104) from RGCs associated with overlapping regions of the visual field, denoted by dashed curve 108 in FIG. 1. Over time, the neurons 102 learn to respond to features presented in the visual input, and develop respective receptive fields as described, for example, in co-pending and co-owned U.S. patent application Ser. No. 13/152,119, entitled "SENSORY INPUT PROCESSING APPARATUS AND METHODS", incorporated supra. Learning may involve changing of synaptic weights of feed-forward connections to the neurons from RGCs, for example. In some cases, these learned receptive fields correspond to orientated receptive fields resembling simple cells observed in biology.
In some applications, visual receptive fields may be described in two dimensions as response to certain patterns of light representing visual features in the image (e.g. oriented lines, color patterns, or more complex shapes, etc.) Receptive fields may also have a temporal component, such that the receptive field is a two-dimensional shape that changes with time until the point of firing of the cell.
Accordingly, there is a salient need for additional mechanisms to produce receptive field diversity and improve feature detection capabilities of the network when processing sensory inputs, such as for example by introducing competition for features among neurons.

Spiking neuron network apparatus and methods


In an image processing device and image processing method in which first image data consisting of a plurality of color data and constituting image information for each pixel are input, and second image data consisting of a plurality of color data are calculated and output, after color conversion of the first image data, dither processing is applied to produce the second image data. As a result, information of the fractional part generated as a result of the color conversion is not omitted but preserved. Tone conversion may be performed after the color conversion, and before the dither processing. The image processing device or image processing method can restrain reduction in the number of colors that can be expressed, and restrain the generation of discontinuities (irregularities) in the change of data, while realizing an “exact color reproduction” or “preferred color reproduction.”

1. Field of Invention
The present invention relates to data processing used for example in full-color printing related equipment, such as printers, video printers, scanners, or the like, and image processing equipment such as those for generating computer-graphics images, or display devices such as monitors, and in particular to an image processing device and method for image-processing the image data represented by three colors of red, green and blue, or yellow, cyan and magenta, to be suitable for the equipment used.
2. Description of Related Art
In the field of printing, color conversion is an essential image technology for compensating for deterioration of printed images, due to color-mixing property caused by the fact that inks are not of pure colors, and due to non-linearity of the image printing, and to output printed images with a good color reproducibility. In display devices such as monitors, color conversion is effected as image processing for outputting (displaying) an image with a desired color reproduction characteristics to be suitable for the conditions in which the device is used, in displaying the input color data. The color conversion can be realized by a table conversion method or a matrix calculation method.
A representative example of table conversion method is a three-dimensional look-up table method, in which image data represented by red, green and blue (hereinafter referred to as "R, G, B") are input, and image data of R, G, B, or complementary color data of yellow, magenta and cyan (hereinafter referred to as "Y, M and C" stored in advance in a memory, such as a ROM are output. This method permits use of any desired conversion characteristics so that color conversion with a good color reproducibility can be achieved.
A problem associated with the table conversion method is the size of the memory required. In a simple configuration in which, data to be output is stored for each combination of the input image data, a memory with a capacity of about 400 Mbits is needed. For instance, Japanese Patent Kokai Publication No. S63-227181 discloses a method of compressing the memory capacity, but the required capacity is still about 5 Mbits. Thus, this method requires a memory of a large capacity for each conversion characteristics, and it is difficult to implement the method by means of LSIs. Another problem is that the method cannot be flexibly adopted to changes in the use conditions or the like.
In the matrix calculation method, the following equation (1) is a basic calculation equation used for converting certain image data Ri, Gi, Bi to another image data Ro, Go, Bo.
                              [                                                    Ro                                                                    Go                                                                    Bo                                              ]                =                              (            Aij            )                                          [                                                            Ri                                                                              Gi                                                                              Bi                                                      ]                                              (        1        )
In the equation (1), i=1 to 3, j=1 to 3.
When color conversion is performed by the matrix calculation according to the equation (1), no large memory is required, so that the method can be implemented easily by means of LSIs, and the method can be adopted flexibly to the changes in the use conditions. On the other hand, the conversion characteristics which can be realized are limited by the matrix calculation equation, and the flexibility in the conversion characteristics is inferior to the three-dimensional look-up table method.
It will thus be understood that the table conversion method and the matrix calculation method used for color conversion have respective advantages and disadvantages. A problem common to both methods is that the number of expressed colors is reduced by the color conversion, and the discontinuities (irregularities) in the change in the data occur.
FIG. 27 is a block diagram showing an example of configuration of a conventional image processing device. In FIG. 27, reference numeral 1 denotes a color converter. The color converter 1 performs color conversion on input color data R1, G1, B1 constituting input image data, to calculate and produce output color data R3, G3, B3 constituting output image data. The color data R1, G1, B1 represent red, green and blue, respectively. The color data R3, G3, B3 also represent red, green and blue, respectively. The color conversion that is performed at the color converter 1 may be that of the table conversion method, or of the matrix calculation method, as described above. In the following description, it is assumed that in the image processing device shown in FIG. 27, the output color data R3, G3, B3 are calculated by a matrix calculation according to the following equation (2).
                              [                                                    R3                                                                    G3                                                                    B3                                              ]                =                              (            Aij            )                                          [                                                            R1                                                                              G1                                                                              B1                                                      ]                                              (        2        )
Here, it is assumed that each of the input color data R1, G1, B1, and the output color data R3, G3, B3 is six-bit data, and can express any value of 0 to 63. It is also assumed that each of the input color data R1, G1, B1 assumes all the values of 0 to 63, and the combination of the input color data R1, G1, B1 have 64*64*64=262,144 values. In other words, the input color data R1, G1, B1 can express 262,144 colors.
Let us assume that the matrix coefficients Aij used in the matrix calculation according to the equation (2) have values represented by the following equation (3).
                              (          Aij          )                =                  [                                                    1.0                                            0.0                                            0.0                                                                    0.0                                            1.0                                            0.0                                                                    0.2                                                              -                  0.2                                                            0.8                                              ]                                    (        3        )
FIG. 28 shows the relationship between the input color data R1, G1, B1 input to the color converter 1, and the output color data R3, G3, B3 calculated by the color converter 1, for each of the nine values of the input color data (data No. 1 to No. 9), where-the matrix coefficients of the equation (3) are used. The nine values of input color data are such that the value of R1 is fixed at "40," the value of G1is fixed at "32," while the value of B1 is reduced from 40 to 32, one by one. In FIG. 28, Ra, Ga, Ba denote values of ideal output color data which would result if the output color data are not limited to six bits. Because the output color data R3, G3, B3 are in fact limited to six bits, the actual output color data R3, G3, B3 are those obtained by rounding Ra, Ga, Ba into six bit data. It is seen from FIG. 28 that the output color data R3, G3, B3 for the input color data R1=40, G1=32, B1=39, and the output color data R3, G3, B3 for the input color data R1=40, G1=32, B1=38 are both R3=40, G3=32, B3=32, i.e., of the same values. Also, the output color data R3, G3, B3 for the input color data R1=40, G1=32, B1=34, and the output color data R3, G3, B3 for the input color data R1=40, G1=32, B1=33 are both R3=40, G3=32, B3=28, i.e., of the same values.
As has been exemplified, a plurality of sets of input color data are converted to the same output color data, while the same input color data will not be converted to different sets of output color data, so that the number of colors that are expressed is reduced. That is, the number of colors expressed by the output color data R3, G3, B3 is smaller than 262,144.
FIG. 29 is a graph showing the relationship between the data numbers shown in FIG. 28, and the blue component B1 of the input color data, the value Ba of the blue component of the ideal output color data, and the blue component B3 of the output color data. It is seen from FIG. 29, that the blue component B1 of the input color data and the value Ba of the blue component of the ideal output color data vary smoothly, while the blue component B3 of the color data includes discontinuous (irregular) data change.
As has been described, the conventional image processing device and image processing method are associated with the problem that the number of colors that can be expressed is reduced by the color conversion. Moreover, the discontinuous (irregular) data change is generated by the color conversion. The color data output from the image processing device is supplied to an image display unit such as liquid crystal panel, and is displayed as an image. Thus, while the image display unit can express 262,144 colors, for instance, the number of colors expressed by the output color data R3, G3, B3 output from the image processing device is smaller than 262,144. This means that the capacity of the image display unit in terms of the number of colors which it can display cannot be fully utilized. Moreover, because of the discontinuity (irregularities) in the change of the data, the image will have parts where there is a larger or more sudden tone change and parts where there is a smaller or more gradual tone change, with the result that the reproduced image on the image display unit is not natural. In particular, if the an irregularity of the tone change occurs in the parts where the data varies gradually, a phenomenon called false edge by which an edge is seen as if it existed at a part where there is actually no edge.
The above described problems are more serious when the color data is changed to a larger extent by the color conversion at the color converter. There are different types of color reproduction, i.e., an "exact color reproduction" and a "preferred color reproduction." The "exact color reproduction" is an exact or faithful color reproduction that is as close as possible to the original image. To realize the exact color reproduction, it is necessary to perform color reproduction which matches with the method of generation of the input image data. Specifically, it can be conceived to perform color reproduction using a standard color space such as those of NTSC or sRGB. On the other hand, a "preferred color reproduction" is a color reproduction that is preferred by a human being, taking account of the characteristics of the human visual perception, and memory colors, and is not necessary identical with the "exact color reproduction."
In a color reproduction used for display of moving pictures, such as those of television pictures, a "preferred color reproduction" is often aimed at. In the memory colors of human beings, there is a tendency that the color of the sky, and the green color of the grass are memorized as colors which are brighter, or of a higher saturation. Accordingly, for realizing a "preferred color reproduction," color conversion to increase the chroma and lightness of the colors is often applied to the input color data, so that the colors are changed to a greater extent. Moreover, even in the "exact color reproduction," it is not rare that the colors are changed to a substantial extent. This is because the color gamut of the image display device is narrower than the color gamut of the color space used in the generation of the image data, or the standard color space.
The conventional image processing device or image processing method is thus associated with a problem that the number of colors expressed is reduced by the color conversion, and that discontinuities (irregularities) in the change of data are created by the color conversion. Since the color data output from the image processing device are input to an image display unit such as a liquid crystal panel, and an image corresponding to the color data is displayed, the reduction in the number of the colors expressed means that the capacity of the image display unit in terms of the number of colors which it can display is not fully utilized. Moreover, because of the discontinuities (irregularities) in the change of the data, there will be parts where the change in the tone is large or sudden, and the parts where the change in the tone is small or gradual, with the result that the reproduced image displayed on the image display unit may be unnatural.

Image processing device and image processing method


Therapeutic system with implantable therapeutic unit (ITU) comprising control unit (CU), memory, telemetry unit connected (in)directly to CU for wireless bidirectional transmission of data to/from external device (ED) and detection unit for detecting physiological patient data or operational data. CU triggers outgoing data transmission (DT) from ITU to ED based on preselected internal events and establishes standby mode for reception on part of telemetry unit for receiving beginning (header) of incoming DT from ED to therapeutic unit exclusively within preselected response time window after DT from ITU to ED. System designed to add to incoming DT follow-up signaling data which signals an imminent follow-up examination, whereby CU also prompts sensor unit at preselected time point in response to receipt of follow-up signaling data to detect preselected physiological data required for follow-up examination or to detect operational data of therapeutic and store in memory and transmit with subsequent outgoing DT to ED.

1. Field of the Invention
The invention relates to a therapeutic system having an implantable therapeutic unit, e.g., an implantable medical device such as a cardiac pacemaker or a cardioverter/defibrillator.
2. Description of the Related Art
Implantable medical devices such as therapeutic units may be equipped with a bidirectional telemetry unit to be able in this way to communicate with a central remote service center via an external device near the patient (patient device). A physician treating the respective patient has patient-specific access to the service center and can retrieve physiological or implant-specific data, for example, from the service center after it has previously been sent from the therapeutic unit via the patient device to the service center.

Therapeutic unit and therapeutic system supporting a follow-up examination


The technology disclosed in this patent document can be implemented to provide an analog front part of an optical receiver module for coherent optical detection where the optical receiver module receives the optical input from a fiber link, performs optical to electrical conversion and analog processing for carrier frequency compensation, optical phase noise compensation and polarization rotation, and generates an analog electrical output for subsequent signal processing for coherent optical detection. The analog processing for the polarization rotation is placed downstream from the analog processing for carrier frequency compensation, and in some implementations, downstream from the analog processing for optical phase noise compensation.

Optical communications via fiber networks can be adversely affected by certain physical properties or processes in optical fiber, such as optical attenuation, chromatic dispersion (CD), polarization mode dispersion (PMD), optical phase noise (PN) and nonlinear optical effects in optical fiber. Coherent optical detection technologies have been developed to mitigate those adverse effects in which a local oscillator (LO) laser (e.g., a continuous-wave laser) is used in an optical receiver to coherently combine with the received optical transmission signal before being detected by an optical detector. This coherent optical detection with the LO laser is used to obtain the optical phase information in the received optical transmission signal.
Coherent optical detection can be used to increase more information to be carried in one optical channel than the corresponding direct detection. Because of that advantage, coherent optical detection can be used to improve long hall communications via fiber links. For optical communications over shorter distances that are much more sensitive to the price, footprint, and power dissipation, coherent optical detection technologies are not presently used in most commercial deployment. Coherent optical detection technologies also allow compensate for such deteriorating effects as Chromatic Dispersion (CD), Polarization Mode Dispersion (PMD), and frequency dependent losses in electrical and opto-electrical elements. However,
One of the approaches to coherent optical detection is using digital signal processing (DSP) in the digital domain to reduce adverse impacts of the transmission system impairments.

Coherent optical receiver with improved noise performance for optical fiber communication links


The present invention provides a method and apparatus for autonomously detecting whether a reference signal within an OFDM signal transmitted by a remote transmitter is or is not muted for a given transmission time. Muting or puncturing may be applied to all or only a portion of the reference signal. The method, which may be carried out in an appropriately configured radio apparatus, includes receiving the OFDM signal and calculating a first comparison metric from signal samples of the OFDM signal corresponding to a first set of resource elements of the OFDM signal, and calculating a second comparison metric from signal samples of the OFDM signal corresponding to a second set of resource elements of the OFDM signal. The method continues with determining whether the reference signal is or is not muted for the given transmission time, by comparing the first and second comparison metrics, and foregoing or performing reference signal measurements responsive to determining that the reference signal is or is not muted.

The possibility of identifying user geographical location in the network has enabled a wide variety of commercial and non-commercial services, including navigation assistance, social networking, location-aware advertising, emergency calls, etc. Different services may have different positioning accuracy requirements imposed by the application. In addition, certain regulatory requirements on the positioning accuracy for basic emergency services exist in some countries, i.e., FCC requirements for E911 calls in the United States.
In many environments, the position can be accurately estimated by using positioning methods based on GPS (Global Positioning System). Nowadays networks also often have the possibility to assist user equipment ("UEs"), to improve their receiver sensitivities and GPS startup performance. Such assistance procedures are referred to as Assisted-GPS positioning, or A-GPS. GPS or A-GPS receivers, however, may not necessarily be available in all wireless terminals. Furthermore, GPS-based positioning often fails in indoor environments and urban canyons because of poor GPS reception in such circumstances. A complementary terrestrial positioning method, called Observed Time Difference of Arrival (OTDOA), has therefore been standardized by the Third Generation Partnership Project (3GPP).
In accordance with OTDOA-based positioning, a UE measures the timing differences for downlink reference signals received from multiple distinct locations, e.g., from multiple cells in a wireless communication network. For each (measured) neighbor cell, the UE measures a Reference Signal Time Difference (RSTD), which is the relative timing difference between a neighbor cell and a reference cell. The UE position estimate is then found as the intersection of hyperbolas corresponding to the measured RSTDs. At least three measurements from geographically dispersed base stations with a good geometry are needed to solve for two coordinates of the terminal and the receiver clock bias.
Precise knowledge of the transmitter locations and transmit timing offset are needed to solve for the UE's position. Position calculation can be conducted, for example, by a positioning server in the network, e.g., an E-SMLC in a Long Term Evolution (LTE) network, or the UE may carry out at least a portion of the calculations. The former approach corresponds to the UE-assisted positioning mode, whilst the latter corresponds to the UE-based positioning mode.
To enable positioning in LTE and facilitate positioning measurements of a proper quality and for a sufficient number of distinct locations, new physical signals dedicated for positioning have been introduced and low-interference positioning sub-frames have been specified in 3GPP. The new physical signals dedicated for positioning measurement are referred to as "positioning reference signals" or PRSs.
Conventionally, for a given cellular network transmitter, PRSs are transmitted from one antenna port (R6) according to a pre-defined pattern. For example details on PRS patterns, see section 1.1.2 of the Technical Specification identified as 3GPP TS 36.211, "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation", v9.1.0, 2010-03-30 (hereafter "TS 36.211"). As a particular approach to patterning, a frequency shift that is a function of Physical Cell Identity (PCI) can be applied to the specified PRS patterns, to generate orthogonal patterns modeling an effective frequency reuse of six. Doing so makes it possible to significantly reduce neighbor cell interference on the measured PRSs and thus improve positioning measurements.
Even though PRSs have been specifically designed for positioning measurements and in general are characterized by better signal quality than other reference signals, the standard does not mandate using PRS. Other reference signals, e.g. cell-specific reference signals (CRSs), therefore, at least in principle, can be used for positioning measurements. However, as noted, PRSs are dedicated for use in making positioning measurements.
PRSs are transmitted in pre-defined positioning sub-frames grouped by several consecutive sub-frames NPRS, which constitute one positioning occasion. Positioning occasions occur periodically with a certain periodicity of N sub-frames. That is, the time interval between two positioning occasions defines the periodicity of positioning occasions, specified in the number of transmission sub-frames. The standardized periods N are 160, 320, 640, and 1280 ms, and the number of consecutive sub-frames are 1, 2, 4, and 6.
Further, as previously noted, Section 1.1.1 of TS 36.211 provides that PRSs are transmitted within a given LTE network cell from one antenna port (R6) in accordance with a pre-defined pattern. The currently specified PRS patterns may be understood in terms of the resource elements (REs) within a block of 12 subcarriers over 14 OFDM symbols (1 ms sub-frame with normal cyclic prefix).
A set of frequency shifts can be applied to the predefined PRS patterns to obtain a set of orthogonal patterns which can be used in neighbor cells to reduce interference on the PRSs and thus improve positioning measurements. That is, these techniques, which model an effective frequency reuse of six, reduce PRS interference between cells and thereby improve the quality of PRS measurements made by any given UE with respect to the PRSs being transmitted for a given cell. As for the frequency-shift based reuse, the frequency shift is defined as a function of Physical Cell ID (PCI) as follows:vshift=mod(PCI,6).Notably, PRSs from any given cell can be muted for all or part of a given positioning occasion. Such muting constitutes transmitting the PRSs at zero or substantially-reduced power (as compared to non-muted transmission powers). See FIG. 2 for an example illustration of frequency shifting and see 3GPP TS 36.355, "Evolved Universal Terrestrial Radio Access (E-UTRA); LTE Positioning Protocol (LPP)", v9.0.0, 2010-01-05 (further referred to as "TS 36.355"), for more muting details.
To improve detection of PRS, i.e. to allow for detecting PRS from multiple sites and at a reasonable quality, positioning sub-frames have been designed as low-interference sub-frames (LIS) and data transmissions are suppressed in general in positioning sub-frames. This approach means PDSCH shall not be transmitted to the UE during the PRS sub-frames. The result is that in synchronous networks, PRSs are ideally interfered with only by PRSs from other cells having the same PRS pattern index (i.e. same vertical shift, vshift) and not by the data transmissions.
In addition to the use of LIS, PRSs can also be transmitted during the sub-frames configurable for the Mobile Broadcast Single Frequency Network (MBSFN). These sub-frames do not contain user data, and only the first 2 OFDM symbols in each MBSFN sub-frame may contain common control channels (e.g., PDCCH) or physical signals (e.g., CRS). In LTE, up to 6 downlink sub-frames in a frame can be configured for the MBSFN. Due to no data transmissions, the interference is reduced in these sub-frames.
In the case of both LIS and MBSFN sub-frames, an important observation is that there exist REs whereby there are: (a) resource elements exclusively for PRS (REPRS); (b) resource elements with non PRS signals (RENON-PRS); and (c) resource elements which are completely empty or unused (REUNUSED). Note that the unused REs, REUNUSED, may be considered as a subset of the non-PRS REs, RENON-PRS.
In partially aligned asynchronous networks, PRSs can still be interfered with by transmissions over data channels, control channels or any physical signals when positioning sub-frames collide with normal sub-frames. This effect is minimized by partial alignment, i.e. by aligning the beginning of positioning sub-frames in multiple cells within one-half of a sub-frame with respect to some time base. Furthermore, in practice, interference on PRS REs may also be caused by other factors such as poor synchronization or large delay spread.
In any case, in using PRSs for OTDOA positioning, a UE may have to deal with PRSs from a neighboring cell that are much weaker than those received at the UE from its own (serving) cell. Furthermore, without the approximate knowledge of when the PRSs are expected to arrive in time and according to what pattern, the UE is obligated to perform signal searching within a large time and/or frequency window, which negatively impacts the time and accuracy of PRS measurements and increases UE complexity.
To facilitate PRS measurements by UEs, the network transmits assistance data, which includes, among other things, reference cell information, a neighbor cell list containing the PCIs of neighbor cells, the number of consecutive downlink sub-frames, PRS transmission bandwidth, frequency, etc. Of course, as noted, the PRSs in any given cell may be muted at given positioning occasions. If a given cell mutes its PRS transmissions for given positioning occasions, that muting generally applies for all PRS REs within the same sub-frame over the entire PRS transmission bandwidth.
On this point, certain optional signaling regarding muting is specified in TS 36.355, but there is no standardized muting pattern. Further, it remains open whether such signaling will be applicable to asynchronous networks. Still further, the possibilities for coordinated muting among transmitting nodes are limited. Thus, the contemplated muting signaling may not be very helpful, for example, for home eNodeBs.
Additionally, the use of blank subframes for "hetnets" (heterogeneous networks) and related signaling is not defined, and there is the possibility that PRS muting pattern is masked by the general hetnet pattern. As a further complication, it is worth noting that hetnet-related muting or puncturing can be applied not only over certain subframes, but also in frequency over certain subframes. Further, muting has been specified as a non-critical extension for Rel-9, meaning that there may be Rel-9 UEs that do not support muting signaling.
In principle, PRS muting can also be applied on OFDM symbol basis. This implies that the PRS muting need not be applied in all of the OFDM symbols in the sub-frame. However, all PRS REs within an OFDM symbol are muted. According to the current formulation presented in 3GPP TS 36.213, "Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures", v9.1.0, 2010-03-30, (further referred to as "TS 36.213"), the PRS muting shall be applied only on a positioning occasion basis (i.e., it is proposed that the transmit power on PRS will be constant over the positioning occasion). However, as noted, the hetnet pattern may not follow the PRS pattern, and, in general, muting may be applied on a sub-frame basis, or even decided at the symbol level. Furthermore, positioning measurements are not required to be performed on PRS, they may be performed, for example, on CRS or other signals for which no muting information may be signaled at all.
A muted PRS or punctured RE is similar to a non-scheduled RE or otherwise "empty" RE. Because of imperfections in signal transmission, reception, and processing, and because of interference and other impairments, even a non-scheduled PRS RE transmits noise. However, even allowing for interference noise power, the transmit power level of a PRS RE when PRS muting is applied is typically well below the transmit power level of a PRS RE when PRS muting is not applied. For instance, the difference between the un-muted and muted PRS levels can be in the order of 30 dB (especially for hetnet).
Muting or puncturing may also be random, where each cell (eNodeB) selectively mutes its PRS transmissions, and where the decision to mute or not is made with some probability. In a simple implementation of random muting, neighboring eNodeBs do not coordinate their muting decisions. The probability at which any given eNodeB makes its selective muting decisions may be statically configured. One advantage of this approach is that no coordination signaling is needed among eNodeBs, as the muting decisions are made locally for each eNodeB or cell. One disadvantage is that real networks are inhomogeneous, with different cell coverage areas and user densities, and possibly different types of base stations. The optimal configuration of such probabilities may also vary, for example, over the day and over the week and on the cell basis, which makes static configurations not the best option from the practical point of view.
These variations imply that setting optimal muting probabilities is a tedious task. Furthermore, there may be multiple patterns in the network (e.g. PRS pattern and hetnet pattern). Even if optimal muting probabilities could be set or maintained for the eNodeBs, the UEs operating in the corresponding cells of the network would not be appraised of the muting decisions. As such, a given UE would not know whether the PRS from a given cell is or is not muted for any given positioning occasion. Without such knowledge, the UE does not know whether to make PRS measurements with respect to that cell, which adds to UE complexity and can degrade PRS measurement results.
One approach that addresses at least some of the issues, including random muting, involves designing a limited set of muting patterns and mapping the muting pattern IDs to PCIs. This approach offers the advantage of providing a table of muting patterns and PCI in the assistance information, meaning that a UE can use the assistance information to determine when the PRSs in a given cell of interest are muted. As a disadvantage of this approach, however, the muting patterns either need to be hard coded in the UEs or received from the network.
The first solution is not appropriate for all UEs, e.g., older UEs and any Rel-9 UEs that do not implement support for muting signaling, while the second solution adds to the signaling requirements of the network. In any case, mapping muting patterns to PCIs will most likely not result in an optimal muting configuration in non-uniform real networks that may also have a multi-layer structure. In other words, with this approach, the muting configuration is fixed and is impossible to re-optimize unless PCI planning is redesigned for the entire network specifically to complement positioning, which likely is not a top priority from the network operator's perspective.
One state-of-the-art approach to blind detection uses correlation principles to detect the presence or absence of a known reference or pilot signal. According to this process, a UE correlates the received signal with all possible pre-defined reference signal waveforms and compares the correlation result to an absolute threshold. No selective measurement over subframes or symbols or REs is performed, to exclude certain PRS REs within the total measured interval. Low correlation indicates that the signal is absent, i.e., not transmitted within the considered search window.
If the comparison is made based on (coherent and/or non-coherent) accumulations over all measured sub-frames over the entire measured interval, then muting detection is essentially the same as the classical signal detection. When the muting pattern is not known to the UE and the measured signal can be muted in shorter intervals, i.e. the muting may occur in some sub-frames and may not occur in the other sub-frames within the same measured interval, then with the state of art, the signal would still be accumulated over the entire measurement interval even though in some sub-frames the signal is not present. With a known muting pattern or a known set of punctured REs, the non-present PRS REs may be excluded from the correlation, but without this knowledge and with a full muting flexibility (e.g., when muting can be applied in any sub-frame or its part, any part of the bandwidth in the muted sub-frame and during any time interval) the UE would be obligated to implement blind detection of muting for any such sub-frame, bandwidth or their parts.
This implies that the advantage of signal accumulation, which increases the correct detection probability and is necessary at low Signal-to-Interference Ratios (SINRs) when the detection probability is low, cannot be exploited if flexible muting is in use by the network—unless, of course, the UEs are appraised of the muting patterns in use. This problem is exacerbated in the sense that a given UE must reliably detect and measure PRSs from multiple cells (e.g., even more than the theoretically-required three cells).
Thus, while signal accumulation improves correlation detection performance, it is, in practice, difficult for the UE to maintain an appropriate absolute threshold for evaluating the correlation results. Hence, non-muted portions of the PRSs or more specifically the resource elements in which the PRS is not muted may be mistakenly identified or detected or estimated by the UE or the target device as being muted, or vice versa. These mistakes or detection errors degrade the PRS measurements and, correspondingly, the accuracy of positioning determinations.

Method and apparatus for reference signal muting detection in a wireless communication network


The invention is directed to a system and method for detecting substances, such as explosives and/or drugs, using, in part, short bursts of energy light from a relatively low energy strobe. Embodiments include coupling the strobe with a detector for use in a portable hand-held unit, or a unit capable of being carried as a backpack. Embodiments further include placement of one or more stroboscopic desorption units and detectors in luggage conveyors systems, carry-on X-ray machines, and check-in counter locations. Embodiments further comprise the use of a strobe or another energy source to assist in maintaining the integrity of a SERS substrate surface operatively associated with the detector system, wherein the SERS substrate may be positioned in hand wand spaced apart from at least a portion of the detector. In another embodiment, the Raman excitation source may be located directly in the hand wand of a portable stroboscopic detection system.

Explosives and other controlled substances, such as drugs, have become major societal problems. Increasingly, terrorist acts using explosives are becoming a problem not only for countries in the Middle East but also for Western countries in other parts of the world. Explosives constitute a weapon used by terrorists and insurgents, wherein the explosives may be hidden in a myriad of devices; however, it is typically difficult for a person handling explosives to avoid contamination after coming into contact with an explosive or explosive device because explosives readily adhere to surfaces.
In addition to explosives, drug abuse has been a longstanding problem for Western countries and consumes large amounts of law enforcement resources each year. Canines, metal detectors, and "sniffer" detectors have been used at various locations, such as airports, border crossings, and the like to detect explosive devices and illegal drugs. These measures have had mixed success.
Another measure that has been employed to detect contraband substances has been to collect loose particles from surfaces or skin with a vacuum cleaner or a swipe. The swipe or the particles collected by the vacuum are then heated to release the vaporizable material for analysis. This approach is in routine use at airports throughout the world for screening airline passengers. An example of such a system is the Barringer™ Ion Scan System™; however, this technique has drawbacks. For example, the use of swipes or particle vacuums is an intermittent process, which requires manual intervention between the sampling and analysis. This is a time consuming approach that is inherently slow, although it may optionally be used in conjunction with at least one embodiment of the present invention.
Previously disclosed devices for volatilizing certain substances for detection include a high-energy apparatus disclosed in U.S. Pat. No. 6,895,804. The content of U.S. Pat. No. 6,895,804 is incorporated herein by reference in its entirety. The landmine detection apparatus of the '804 patent applies a relatively high amount of energy to the sample target that is generally intended to be soil. To provide the requisite energy, the radiation source of the '804 patent is powered by a relatively high amount of energy, and therefore, is limiting in its ability to serve as a self-contained backpack unit, handheld device, or other relatively compact portable device. In addition, high-energy strobes are slow to recharge, utilize kilowatts of energy to power, and are heavy as a self-contained unit that includes a power source.
U.S. Pat. No. 6,828,795, incorporated herein by reference, suggests use of an ion mobility spectrometer with a heat source, but energy levels have not been provided. U.S. Patent Application Publication No. 2005/0007119 A1, related to the '795 patent, is also incorporated herein by reference. The '795 patent discloses using an electrostatic precipitator to take out particulates, presumably to keep them out of the ion mobility spectrometer. It is noted here that, in at least one embodiment, the present invention advantageously releases a plume of particulates that is then able to form at least part of the signal.
Typical trace explosive detectors employing vapor and/or particle analyses rely on an interval-based analysis that requires discrete and separate steps for (1) sampling and (2) detection. The combination of these two steps may take anywhere from 15 to 60 seconds, or more. Thus, it would be advantageous to provide an apparatus for sampling multiple target surfaces while the detector is processing the sampled information.
Surface Enhanced Raman Spectroscopy (SERS) can be used for trace detection of chemical contaminants, such as explosives or drugs. SERS employs microscopically roughened, or "activated" metals, normally noble metals, that adsorb the compound of interest. Existing SERS detectors have traditionally been hindered in application due to the length of time that the SERS substrate surface remained available for new sample material to adsorb to the nano-texture of the substrate. Therefore, the SERS substrate requires cleaning or refreshing to continue to function properly. Such cleaning of the substrate surface has been accomplished in prior art by a number of methods.
One such method includes disposing of the used substrate and using a new substrate. As a result, this further requires the effort of recalibration of the signal amplification factor, or otherwise having to fabricate the substrate surface using extreme precision controls so that recalibration is not necessary. Either way, the result is high costs because of instrument down-time for substrate replacement and costs associated with fabrication and procurement of the replacement substrates.
Another way of refreshing the SERS substrate is to heat the substrate to desorb the adsorbed materials. This is slow and requires considerable power to heat and subsequently re-cool the substrate, thus making it unattractive for battery powered equipment.
A further method of cleaning or refreshing the SERS substrate is to increase the ambient air flow across the substrate surface to favor desorption of the adsorbed materials from the substrate due to solid-gas partitioning. However, this process will only restore the surface over time if the air flowing across the surface is clean and does not contain other materials that will in-turn adsorb on the surface. In addition, this method relies on rather slow thermodynamics and the time it takes will cost the system overall power in idle time. In general, this process is slow because the desorption of contaminants with low vapor pressures is particularly time consuming.
Yet another method of cleaning or refreshing the SERS substrate is to remove the substrate and clean the substrate using solvent rinsing, heating, and/or wiping with a clean or solvent soaked swab. Although relatively quick, this costs labor, is prone to human neglect and/or error, and is subject to irreproducibility. Furthermore, contaminates from the cleaning process may also adsorb onto the substrate. Thus, it would be advantageous to provide an improved means for refreshing or cleaning the SERS substrate.
As noted above, present techniques for airport security include sometimes screening baggage for trace explosives by manually swiping the surface of the baggage and analyzing the swipe, such as by using Ion Mobility Spectrometry. Not all bags are tested for trace explosives, with carry-on baggage typically being X-rayed but not always screened for traces of explosives. Thus, there would be an advantage to automatically screening all baggage, whether checked or carry-on, for explosives. In addition, upon arrival at a destination airport, government agencies at the destination airport typically also screen baggage, wherein such screen efforts typically include searches for drugs. Thus, it would be advantageous to be able to automatically screen baggage upon arrival, such as when baggage is unloaded from international flights. Accordingly, among other types of screening uses, such as crime scene analysis, there is clearly a need for automatically screening airline baggage and carry-on items for traces of explosives and drugs.

Stroboscopic liberation and methods of use


Methods, apparatuses, and articles for receiving, by a server, a plurality of identifiers associated with a client device are described herein. The server may also encrypt a plurality of encoding values associated with the plurality of identifiers using a first key of a key pair of the server, and generate a token uniquely identifying the client device, a body of the token including the encrypted plurality of encoding values. In other embodiments, the server may receive a token along with the plurality of identifiers. In such embodiments, the server may further verify the validity of the received token, including attempting to decrypt a body of the received token with a key associated with a second server, the second server having generated the received token, and, if decryption succeeds, comparing ones of the plurality of identifiers with second identifiers found in the decrypted body to check for inconsistencies.

Advances in microprocessor technologies have made computing ubiquitous. Advances in networking and telecommunication technologies have also made computing increasingly networked. Today, huge volumes of content and services are available through interconnected public and/or private networks. Ironically, the ubiquitous availability of computing has also led to abuses, such as denial of service attacks, viruses, spam, and phishing. For various on-line applications, it is increasingly desirable to uniquely identify a computing device (hereinafter, simply device).
Prior art methods of identifying devices have included the usage of device serial numbers, media access control (MAC) addresses and so forth.

Creating and verifying globally unique device-specific identifiers


An interactive user interface element makes content (e.g., images, news, standard indexed Web content) available to a user of online map services (e.g., virtual globe program). In some implementations, when zoomed out on a feature displayed in map imagery (e.g., virtual globe imagery), the user sees a non-interactive user interface element (e.g., a feature label). As the user expresses greater interest in the feature by, for example, flying (“zooming”) toward the feature, the non-interactive user interface element is replaced by (or morphs into) an interactive user interface element (e.g., a feature label including a clickable icon). In some implementations, a user's interaction with the interactive user interface element (or navigation actions in the imagery) launches a content access portal (e.g., a balloon) for presenting content (e.g., text, digital photos, video, audio) and/or providing access (e.g., links) to related content.

A virtual globe is a 3D software model or representation of the Earth or another world. A virtual globe provides the user with the ability to freely move around in a virtual globe by changing a viewing angle and position. One popular program that allows users to navigate a virtual globe is "The Google Earth" client developed by Google, Inc. (Mountain View, Calif.).
The Google Earth client offers a user a high-performance, virtual fly-through experience of a virtual globe's imagery and terrain. Google Earth annotates this imagery and terrain with feature labels denoting cities, islands, mountains etc. As the user "flies around" in Google Earth, labels appear at different levels of scale, depending upon the significance of the geographic feature. For example, a label for the capital city, Paris, will appear at a larger scale ("zoomed-out") than a small hamlet in upstate New York.
When zoomed-out to a scale where many features are visible, users may desire to see feature labels without icons or other placemarks to minimize visual clutter, providing the user with a familiar "map-like" view. The user, however, may also be interested in learning more about a geographic feature (e.g., an island) marked by a feature label, and would like to have easy and immediate access to content related to the feature (e.g., Web content).

Cartographic display of content through dynamic, interactive user interface elements


The present invention features a multi-functional pump for pumping molten metal, which includes a base that is submerged in molten metal having at least two impeller chambers. The base includes one or more inlet openings and one or more outlet openings. Each outlet opening leads from one of the impeller chambers. The invention enables the impeller to be moved to a position to rotate in either impeller chamber or while straddling impeller chambers. This enables the pump to have the versatility to operate in a circulation mode; a transfer mode; two or more circulation modes; two or more transfer modes; and a combination of transfer and circulation modes. The impeller chambers can be stacked over each other and the impeller can be moved vertically in and between impeller chambers. Inventive vaned or barrel type impellers can be used to facilitate pumping while straddling impeller chambers, in view of an elongated bearing member on the impeller that maintains position relative to a bearing ring attached to the base or an inlet protector sleeve. The multifunctional pump of the invention enables infinite adjustment of the impeller using a programmable logic controller that results in positioning of the impeller at any of various locations in the base to achieve any desired output. The inventive pump is ideally suited for use in die casting and scrap submergence applications. Also featured is a method of operating the multifunctional pump of the present invention.

Pumps for pumping molten metal are used in furnaces in the production of metal articles. Common functions of pumps are circulation of molten metal in the furnace or transfer of molten metal to remote locations along transfer conduits or risers that extend from a base of the pump to the remote location. The pump may be located in a separate, smaller chamber such as a pump well adjacent the main hearth.
Currently, many metal die casting facilities employ a main hearth containing most of the molten metal. Solid bars of metal may be periodically melted in the main hearth. Metal scrap such as from aluminum cans is often charged into the molten metal in a scrap well adjacent the main hearth. A transfer pump is located in a separate well adjacent the main hearth. The transfer pump draws molten metal from the well in which it resides and transfers it into a ladle from which the molten metal is taken to a holding furnace and fed into a plurality of die casters that form metal articles. Die casting furnaces employ only a transfer pump, not a circulation pump. When scrap metal is added, it lowers the temperature of the molten metal. Burners located above the molten metal in the main hearth must maintain molten metal temperature while compensating for the drop in temperature caused by scrap charging. A tremendous amount of fuel is required by the burners to heat and maintain the molten metal at a suitable temperature.
In view of the heat applied by the burners at the surface of the molten metal and the cold scrap added to the bath, temperature differences arise in the bath. For example, in a die casting furnace the temperature of molten aluminum might be 1550° F. near the surface of the bath, 1250° F. in a location where the scrap is charged, and 1350° F. near the bottom of the bath. Important considerations in a die casting facility include the consumption of fuel and cleanliness and physical properties of the cast metal articles. Aluminum oxide is formed on the surface of the molten metal as the molten aluminum oxidizes. Aluminum oxide has an affinity for hydrogen gas. It is undesirable to have hydrogen gas in the metal. As the cast metal solidifies it releases trapped hydrogen gas, forming pin holes in the metal articles. Higher temperatures of molten aluminum lead to increased absorption of hydrogen gas and increased pin hole defects with resulting compromise in the physical properties of the metal articles.
Various devices have been proposed for use in submerging metal scrap. One such device disclosed in U.S. Pat. No. 6,217,823 includes a ramp located in a charge well for creating a vortex that pulls scrap down into the molten metal. A drawback of this scrap submerging system is that all of the molten metal is required to be passed through the scrap well. This poses pumping inefficiencies during times when no scrap is being charged. In addition, this may lead to increased generation of oxides due to the greater surface area and turbulence involved in passing molten metal along a vortex all of the time.

Multi functional pump for pumping molten metal