2000-12-07 Assigned to IOSPAN WIRELESS, INC. reassignment IOSPAN WIRELESS, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: GIGABIT WIRELESS, INC.
2000-12-14 Assigned to GIGABIT WIRELESS, INC. reassignment GIGABIT WIRELESS, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: PAULRAJ, AROGYASWAMI J., SAMPATH, HEMANTH, SEBASTIAN, PEROOR K.
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A method and system for selective mode adaptation for transmitting data by spatial multiplexing applicable in communications systems with a transmit unit having multiple transmit antennas or multiple transmit units and a receive unit having multiple receive antennas. A channel descriptor, such as channel matrix H or a channel matrix filter , with has sub-descriptors corresponding to the transmit antennas is determined and a quality parameter, such as signal-to-interference and noise ratio, signal-to-noise ratio or power level are chosen. The quality parameter is assigned a threshold and the sub-descriptor or sub-descriptors whose quality parameters do not meet the threshold are identified and deactivated.
This patent application is a continuation-in-part of patent application Ser. No. 09/464,372 filed on Dec. 15, 1999, now U.S. Pat. No. 6,351,499 and of patent application Ser. No. 09/585,948 filed on Jun. 2, 2000 now U.S. Pat. No. 6,298,092 which are herein incorporated by reference.
The present invention relates generally to wireless communication systems and methods, and more particularly to mode adaptation including selection of transmit antennas in transmit units employing multiple antennas for spatial multiplexing.
Wireless communication systems serving stationary and mobile wireless subscribers are rapidly gaining popularity. Numerous system layouts and communications protocols have been developed to provide coverage in such wireless communication systems.
Wireless communications channels between transmit and receive devices are inherently variable and their quality fluctuates.
Specifically, the quality parameters of such communications channels vary in time. Under good conditions wireless channels exhibit good communication parameters, e.g., large data capacity, high signal quality, high spectral efficiency and throughput. At these times significant amounts of data can be transmitted via the channel reliably. However, as the channel changes in time, the communication parameters also change. Under altered conditions former data rates, coding techniques and data formats may no longer be feasible. For example, when channel performance is degraded the transmitted data may experience excessive corruption yielding unacceptable communication parameters. For instance, transmitted data can exhibit excessive bit-error rates or packet error rates. The degradation of the channel can be due to a multitude of factors such as general noise in the channel, multi-path fading, loss of line-of-sight path, excessive Co-Channel Interference (CCI) and other factors.
By reducing CCI the carrier-to-interference (C/I) ratio can be improved and the spectral efficiency increased. Specifically, improved C/I ratio yields higher per link bit rates, enables more aggressive frequency re-use structures and increases the coverage of the system.
It is also known in the communication art that transmit units and receive units equipped with antenna arrays, rather than single antennas, can improve receiver performance. Antenna arrays can both reduce multipath fading of the desired signal and suppress interfering signals or CCI. Such arrays can consequently increase both the range and capacity of wireless systems. This is true for wireless cellular telephone and other mobile systems as well as Fixed Wireless Access (FWA) systems.
In mobile systems, a variety of factors cause signal degradation and corruption. These include interference from other cellular users within or near a given cell. Another source of signal degradation is multipath fading, in which the received amplitude and phase of a signal varies over time. The fading rate can reach as much as 200 Hz for a mobile user traveling at 60 mph at PCS frequencies of about 1.9 GHz. In such environments, the problem is to cleanly extract the signal of the user being tracked from the collection of received noise, CCI, and desired signal portions summed at the antennas of the array.
In FWA systems, e.g., where the receiver remains stationary, signal fading rate is less than in mobile systems. In this case, the channel coherence time or the time during which the channel estimate remains stable is longer since the receiver does not move. Still, over time, channel coherence will be lost in FWA systems as well.
Antenna arrays enable the system designer to increase the total received signal power, which makes the extraction of the desired signal easier. Signal recovery techniques using adaptive antenna arrays are described in detail, e.g., in the handbook of Theodore S. Rappaport, Smart Antennas, Adaptive Arrays, Algorithms, & Wireless Position Location; and Paulraj, A. J. et al., "Space-Time Processing for Wireless Communications", IEEE Signal Processing Magazine, November 1997, pp. 49-83.
Prior art wireless systems have employed adaptive modulation of the transmitted signals with the use of feedback from the receiver as well as adaptive coding and receiver feedback to adapt data transmission to changing channel conditions. However, effective maximization of channel capacity with multiple transmit and receive antennas is not possible only with adaptive modulation and/or coding.
In U.S. Pat. No. 5,592,490 to Barratt et al., U.S. Pat. No. 5,828,658 to Ottersten et al., and U.S. Pat. No. 5,642,353 Roy III, teach about spectrally efficient high capacity wireless communication systems using multiple antennas at the transmitter; here a Base Transceiver Station (BTS) for Space Division Multiple Access (SDMA). In these systems the users or receive units have to be sufficiently separated in space and the BTS uses its transmit antennas to form a beam directed towards each receive unit. The transmitter needs to know the channel state information such as "spatial signatures" prior to transmission in order to form the beams correctly. In this case spatial multiplexing means that data streams are transmitted simultaneously to multiple users who are sufficiently spatially separated.
The disadvantage of the beam-forming method taught by Barratt et al., Ottersten et al., and Roy III is that the users have to be spatially well separated and that their spatial signatures have to be known. Also, the channel information has to be available to the transmit unit ahead of time and the varying channel conditions are not effectively taken into account. Finally, the beams formed transmit only one stream of data to each user and thus do not take full advantage of times when a particular channel may exhibit very good communication parameters and have a higher data capacity for transmitting more data or better signal-to-noise ratio enabling transmission of data formatted with a less robust coding scheme.
U.S. Pat. No. 5,687,194 to Paneth et al. describes a Time Division Multiple Access (TDMA) communication system using multiple antennas for diversity. The proposed system exploits the concept of adaptive transmit power and modulation. The power and modulation levels are selected according to a signal quality indicator fed back to the transmitter.
Addressing the same problems as Paneth et al., U.S. Pat. No. 5,914,946 to Avidor et al. teaches a system with adaptive antenna beams. The beams are adjusted dynamically as the channel changes. Specifically, the beams are adjusted as a function of a received signal indicator in order to maximize signal quality and reduce the system interference.
The prior art also teaches using multiple antennas to improve reception by transmitting the same information, i.e., the same data stream from all antennas. Alternatively, the prior art also teaches that transmission capacity can be increased by transmitting a different data stream from each antenna. For more information about capacity increases achievable by transmitting different data streams from different antennas the reader is referred to U.S. Pat. No. 5,345,599 to Paulraj, A. J. et al., and to Foschini, G. J., "Layered Space-Time Architecture for Wireless Communication in a Fading Environment when Using Multi-Element Antennas", Bell Labs Technical Journal, Autumn 1996. These two approaches are commonly referred to as antenna diversity schemes and spatial multiplexing schemes.
Adaptive modulation and/or coding in multiple antenna systems involve mapping of data converted into appropriate symbols to the antennas of the transmit antenna array for transmission. In the case of spatial multiplexing there can be no coordination between transmitters, since the transmit antennas can belong to separate base stations or mobiles rather than to a single antenna array. Prior art systems do not teach rules suitable for determining antenna mappings, or, more precisely, antenna selection for varying channel conditions in the spatial multiplexing mode. Development of rules for selecting antennas in the spatial multiplexing mode would represent a significant advance in the art.
The present invention provides a method for selecting antennas for transmitting data over a channel by employing spatial multiplexing, i.e., by transmitting different data streams from different antennas. The method is applicable in communications systems with a transmit unit having multiple transmit antennas or multiple transmit units, e.g., multiple transceiver stations, and a receive unit having multiple receive antennas. The first step of the method involves determining a channel descriptor. In one embodiment the descriptor is a channel matrix H. In another embodiment, where the channel is subject to time delay spread, the descriptor is a channel matrix filter . The channel descriptor has sub-descriptors corresponding to the transmit antennas. Specifically, channel matrix H has sub-descriptors in the form of sub-matrices hi corresponding to the transmit antennas. Channel matrix filter has sub-descriptors in the form of sub-matrix filters also corresponding to the transmit antennas.
The method then calls for choosing a quality parameter and a threshold for the quality parameter. In the next steps, a sub-descriptor which does not meet the threshold is identified and the antenna from among the transmit antennas associated with the sub-descriptor is deactivated.
The quality parameter used in the method can be selected from among signal-to-interference and noise ratio, signal-to-noise ratio and power level. The threshold is typically a minimum acceptable value of the quality parameter. This threshold can be re-set or adjusted and the steps of identifying another sub-descriptor or set of sub-descriptors not meeting the threshold can be repeated. The corresponding transmit antennas are then deactivated.
In case the spatial multiplexed communication is of the type employing a number of sub-carrier tones rather than just one carrier frequency, the sub-descriptors are associated with an average value of the quality parameter. In particular, the average value is the average of the quality parameter over the sub-carrier tones. It is then this average value of the quality parameter which is compared with the threshold to determined whether the threshold is met.
In one embodiment of the method, the sub-matrix hj is removed from the channel matrix H to obtain a subset channel matrix H′. The remaining sub-matrices hi can be rearranged after removal of hj. In particular, the remaining sub-matrices h can be ordered in accordance with the threshold, i.e., in descending order starting with the sub-matrix hi which exceeds the threshold the most or has the best quality parameter.
The data transmitted is typically coded and modulated in accordance with a selected mode. The mode is characterized by a coding rate and a modulation. The setting of the threshold can be based on the selected mode and the selected mode can be based on the quality parameter.
The receive unit can employ any receiver such as a maximum likelihood receiver, a zero forcing equalizer receiver, a successive cancellation receiver, a minimum mean square error equalizer (MMSE) receiver.
In another embodiment, a set of sub-descriptors, i.e., a set of sub-matrices hi or set of sub-matrix filters is identified and transmit unit antennas associated with that set are all deactivated at one time, rather than one by one. This method can be applied in steps as well. A set of antennas or a single antenna not meeting the assigned threshold can be deactivated in each step.
In still another embodiment, the transmit antennas belong to separate transmit units, e.g., to different base stations. In this case the sub-matrix hj can represent the base station transceiver which is to be deactivated to improve the quality parameter at the receive unit.
Systems of the invention can be used for spatial multiplexed communications between transmit units with multiple antennas and receive units with multiple antennas, or between separate transceivers, e.g., base stations, and receive units with multiple antennas. The receive unit has a channel estimation block for determining channel descriptor, a mode selection block for receiving the quality parameter, assigning a threshold to the quality parameter, and identifying among the sub-descriptors of the channel descriptor at least one sub-descriptor not meeting the threshold. The receive unit has a feedback unit for sending feedback related to the at least one sub-descriptor to the transmit unit or, as the case may be, to the base stations.
In case the transmit unit has an antenna array, a controller at the transmit unit receives the feedback and deactivates the corresponding transmit antennas. In case the transmit antennas belong to separate transceivers, a common controller or separate control units can be used to receive the feedback and deactivate the corresponding transceivers or their antennas.
The method of the invention can be employed in multi-tone communications using a number of sub-carrier tones for transmitting data from each transmit antenna.
FIG. 1 is a simplified diagram illustrating a communication system in which the method of the invention is applied.
FIG. 2 is a simplified block diagram illustrating the transmit and receive units according to the invention.
FIG. 3 is a block diagram of an exemplary transmit unit in accordance with the invention.
FIG. 4 is a block diagram of a spatial multiplexing block of the transmit unit of FIG. 3.
FIG. 5 is a block diagram of exemplary receive unit in accordance with the invention.
FIG. 6. is a schematic illustrating the operations performed on the channel matrix H.
FIG. 7 is a block diagram of a mode selection block of the receive unit of FIG. 5.
FIG. 8 is an exemplary flow chart of the method of the invention.
FIG. 9 is a diagram of another embodiment of the invention.
The method and wireless systems of the invention will be best understood after first considering the high-level diagrams of FIGS. 1 and 2. FIG. 1 illustrates a portion of a wireless communication system 10, e.g., a cellular wireless system. For explanation purposes, the downlink communication will be considered where a transmit unit 12 is a Base Transceiver Station (BTS) and a receive unit 14 is a mobile or stationary wireless user device. Exemplary user devices include mobile receive units 14A, 14B, 14C which are portable telephones and car phones and a stationary receive unit 14D, which can be a wireless modem unit used at a residence or any other fixed wireless unit. Of course, the same method can be used in uplink communication from wireless units 14 to BTS 12.
BTS 12 has an antenna array 16 consisting of a number of transmit antennas 18A, 18B, . . . , 18M. Receive units 14 are equipped with antenna arrays 20 of N receive antennas (for details see FIGS. 2, 3 and 5). BTS 12 sends transmit signals TS to all receive units 14 via channels 22A and 22B. For simplicity, only channels 22A, 22B between BTS 12 and receive units 14A, 14B are indicated, although BTS 12 transmits TS signals to all units shown. In this particular case receive units 14A, 14B are both located within one cell 24. However, under suitable channel conditions BTS 12 can transmit TS signals to units outside cell 24.
The time variation of channels 22A, 22B causes transmitted signals TS to experience fluctuating levels of attenuation, interference, multi-path fading and other deleterious effects. Therefore, communication parameters of channels 22A, 22B such as data capacity, signal quality, spectral efficiency or throughput undergo temporal changes. Thus, channels 22A, 22B can not at all times support efficient propagation of high data rate signals TS or signals which are not formatted with a robust coding algorithm.
In accordance with the invention, antenna array 16 at BTS 12 employs spatial multiplexing, reduces interference, increases array gain and achieves other advantageous effects. Antenna arrays 20 at receive units 14 are set up to receive the spatial multiplexed signals from BTS 12. The method of the invention finds an optimum choice of transmit antennas 18A, 18B, . . . , 18M selected adaptively with changing conditions of channels 22A, 22B. In other words, the method of the invention implements an adaptive and optimal selection of transmit antennas 18A, 18B, . . . , 18M, deactivating some of these antennas in accordance with the rules described below to improve performance.
FIG. 2 illustrates the fundamental blocks of transmit unit 12 and one receive unit 14 necessary to employ the method. Transmit unit 12 has a control unit 26 connected to a data processing block 28 for receiving data 30 to be converted to spatially multiplexed transmit signals TS to select transmit antennas 18A, 18B, . . . , 18M for transmission therefrom. An up-conversion and RF amplification block 32 supplies the transmit signals TS to antennas 18A, 18B, . . . , 18M.
On the other side of the link, receive unit 14 has N receive antennas 34A, 34B, . . . , 34N in its array 20 for receiving receive signals RS. An RF amplification and down-conversion block 36 processes receive signals RS and passes them to data processing block 38, which generates a representation 44 of the originally transmitted data 30. Data processing block 38 includes a channel measurement or estimation unit (see FIG. 5) which obtains a measurement of the channel coefficients matrix H characterizing channel 22.
A mode selection block 40 uses matrix H and a chosen quality of service QoS or quality parameter QP to determine which of transmit antennas 18 should be deactivated to improve reception. The quality parameter QP used by block 40 can be any useful signal characteristics measure such as signal-to-interference and noise ratio (SINR), signal-to-noise ratio (SNR), power level. Block 40 makes the determination about which of transmit antennas 18A, 18B, . . . 18M should be transmitting in order to keep the quality parameter above a certain minimum required value or threshold. This selection is fed back as indicated by dashed line 42 to transmit unit 12. In case channel 22 is a time-division duplexed (TDD) channel, which is reciprocal between the receive and transmit units, no separate feedback is required. In response, unit 26 switches off or deactivates the transmit antennas which block 40 has determined should be deactivated.
An exemplary embodiment of a transmit unit 50 for practicing the method of the invention is shown in FIG. 3. Data 52, in this case in the form of a binary stream, has to be transmitted.
Before transmission, data 52 may be interleaved and pre-coded by interleaver and pre-coder (not shown). The purpose of interleaving and pre-coding is to render the data more robust against terrors. Both of these techniques are well-known in the art.
Data 52 is delivered to a conversion unit, more specifically a spatial multiplexing block 56. Block 56 converts data 52 into k streams of symbols at chosen modulation rates and coding rates. For example, data 52 can be converted into symbols through modulation in a constellation selected from among PSK, QAM, GMSK, FSK, PAM, PPM, CAP, CPM or other suitable constellations. The transmission rate or throughput of data 52 will vary depending on the modulation and coding rates used in each of the k streams.
Table 1 illustrates some typical modulation and coding rates with the corresponding throughputs which can be used in the spatial multiplexing method of the invention. The entries are conveniently indexed by a mode number.
The mode column can be used to more conveniently identify the modulation and coding rates which are to be applied to the k streams. Tables analogous to Table 1 for other coding rates and modulation can be easily derived as these techniques are well-known in the art.
Once coded and modulated in symbols, data 52 passes to a switching unit 60. Depending on its setting, switching unit 60. routs modulated and coded k streams of spatially multiplexed data 52 to all or a subset of its M outputs. The M outputs lead to the corresponding M transmit antennas 72 via an up-conversion and RF amplification stage 70 having individual digital-to-analog converters and up-conversion/RF amplification blocks 74. Transmit antennas 72 transmit data 52 in the form of transmit signals TS. In this case transmit antennas T1, T2, . . . TM with the exception of transmit antenna Tj are transmitting coded streams. In other words, k=M−1. The determination to deactivate antenna Tj is made in accordance with the method of the invention as described below.
Transmit unit 50 also has a controller 66 connected to spatial multiplexing block 56 and to switching unit 60. A database 78 is connected to controller 66. Database 78 conveniently contains a table, e.g., a spatial multiplexing look-up table indexed by mode as in exemplary table 1. The convenience of indexing by mode resides in the fact that feedback to transmit unit 50 does not require much bandwidth.
Specifically, transmit unit 50 receives feedback from receive unit 90 (see FIG. 5) via a feedback extractor 80. Feedback extractor 80 detects an antenna number or any other designation which antennas to operate and which to deactivate and forwards this information to controller 66. In some embodiments feedback extractor detects mode number and associated antenna number, and forwards it to controller 66. Controller 66 looks up the mode number in database 78 and thus determines the modulation, coding rate and any other parameters for the associated antenna.
Receive unit 90 can send back a channel descriptor, e.g., a channel matrix H, a channel matrix filter or some other suitable descriptor identifying the action of the channel on transmitted signals TS, to transmit unit 50. In these cases transmit unit 50 can use the channel descriptor in its operation to derive any information in addition to antenna number and mode number to adapt its transmission to channel 22. In the event of using time-division duplexing (TDD), the feedback information, i.e., the channel parameters are obtained during the reverse transmission from receive unit 90 or remote subscriber unit, as is known in the art, and no dedicated feedback extractor 80 is required.
When channel 22 experiences delay spread, it can be modeled as a Finite Impluse Response (FIR) channel, i.e., channel 22 has a memory and any representation of channel 22 should have a time dimension. Depending on the transmission symbol rate, for a given delay spread channel 22 will have some number L of symbol delay taps. When there is no delay spread channel 22 can be represented by an NxM matrix where N is the number of receive antennas 92 (see FIG. 5) and M is the number of transmit antennas 72. When there is delay spread, channel 22 can be represented by a matrix filter which is constructed of H1, H2, . . . HL, where Hi is the N×M channel matrix at i-th delay tap.
When multi-carrier modulation such as OFDM is used, the symbol duration is chosen much longer than the channel delay spread. In this case, each sub-carrier frequency or tone has an individual channel represented by an N×M matrix, i.e., H1, H2, . . . HT where T is the number of sub-carrier tones.
In an embodiment of the invention where inter-symbol interference (ISI) is not a problem, the parameters of channel 22 are expressed by a single channel matrix H. In accordance with this descriptor, transmit signals TS propagating through channel 22 are affected by channel coefficients axy of matrix H. Matrix H is composed of sub-matrices h, here in the form of columns labeled h1, h2, . . . , hj, . . . hM. Each antenna T1, T2, . . . Tj, . . . , TM is associated with a corresponding sub-matrix h1, h2, . . . , hj, . . . hM. The dimension or number of entries in each sub-matrix h is dictated by the number of receive antennas 92 employed by receive unit 90 (see FIG. 5); in this case the number is N. Hence, channel coefficients matrix H is an N×M matrix with channel coefficients axy ranging from a11 to aNM.
FIG. 4 shows a more detailed block diagram of spatial multiplexing block 56. Data 52 received by block 56 is first parsed by parser 58, which is in direct communication with controller 66. Based on feedback obtained from feedback extractor 80, controller tells parser 59 into how many streams data 52 is to be divided. Parser is connected with a multiplexing block 62 and supplies the streams to its coding and modulation blocks 64. Having separate coding and modulation blocks 64 for each stream enables the user to employ different coding rates and modulations in each stream.
FIG. 5 illustrates receive unit 90 for receiving receive signals RS from transmit unit 50 through channel 22 with N receive antennas 92. Receive unit 90 can be any suitable receiver capable of receiving spatial multiplexed receive signals RS via the N receive antennas 92. Exemplary receivers include maximum likelihood receivers, zero forcing equalizer receivers, successive cancellation receivers and minimum mean square error equalizer receivers. Receive unit 90 has an RF amplification and down-conversion stage 94 having individual RF amplification/down-conversion/and analog-to-digital converter blocks 96 associated with each of the N receive antennas 92. The N outputs of stage 94 are connected to a block 98 which performs receive processing, signal detection and decoding and demultiplexing functions. The N outputs of stage 94 are also connected to a channel estimator 100. Channel estimator 100 obtains a measurement of channel 22; in particular, it determines the channel coefficients matrix H representing the action of channel 22 on transmit signals TS.
Estimator 100 is connected to block 98 to provide block 98 with the channel descriptor. The channel descriptor is typically determined by estimator 100 during training; a procedure well-known in the art. In case there is no ISI estimator 100 determines channel matrix H for the independent k streams from the k transmit antennas 72. In case there is ISI estimator 100 determines channel matrix filter with the aid of training sequences which are as long or longer than the delay spread. In multi-carrier operation each sub-carrier tone has a different channel so training is required for all sub-carrier tones. During training estimator 100 determines channel matrices H1, H2, . . . HT for all sub-carrier tones. A deinterleaver and decoder (not shown) can be placed in the data stream if a corresponding interleaver and coder was employed in transmitter 50.
Channel estimator 100 is also connected to a mode selection block 102. Mode selection block 102 is connected to a database 104. Database 104 conveniently contains a look-up table similar to table 1 with quality parameters QP's and threshold values QPth (i.e., the lowest acceptable values) of these QP's for each of the modes. In other words, for any particular QP each mode has an associated threshold QPth, which is conveniently stored in database 104. For example, when SINR is used as QP, then for a given (or required) performance criteria, e.g., a required BER, each mode has a threshold SINRth which depends on its modulation rate and coding rate. Mode selection block 102 can thus access in database 104 the appropriate threshold QPth values for the selected modes.
Alternatively, mode selection block 102 can receive quality parameter QP and threshold value QPth for each mode from an outside source. In yet another embodiment, block 102 can be pre-programmed to use a particular quality parameter QP or make its own selection of quality parameter QP. Also, threshold value QPth can be provided, or pre-set by block 102 or adjusted during operation by either block 102 or some other circuit, as necessary. In the present embodiment, signal-to-interference and noise ratio (SINR) is used as quality parameter QP.
Conveniently, database 104 contains the same entries as database 78 indexed by the same mode numbers. This arrangement makes it particularly easy for selection block 102 to communicate its mode selection for each transmit antenna Ti to transmit unit 50 by sending the mode number. For example, selection block 102 provides transmit antenna number and mode to be used by that transmit antenna pairwise for feedback to transmit unit 50. In fact, antenna number and mode can be arranged in a table for feedback. When a transmit antenna number and corresponding mode are not indicated by block 102, then that transmit antenna Ti is deactivated by controller 66. For active transmit antennas Ti controller 66 retrieves the corresponding coding rate and modulation from database 78. Alternatively, selection block 102 can indicate directly which transmit antenna or antennas Ti are to be deactivated and indicate the modes to be used by active transmit antennas Ti. In some cases, the same mode can be used by all active transmit antennas Ti, e.g., at system start-up. At this time selection block 102 only sends active transmit antennas and mode for feedback to transmit unit 50.
Mode selection block 102 is connected to a feedback block 106 for feeding back the antenna numbers and corresponding modes to receive unit 50. Furthermore, feedback block 106 can also send channel parameters, e.g., in the form of mode number to transmit unit 50. Receiver unit's 90 transmitter 110 is connected to feedback block 106 for transmitting this information back to transmit unit 50.
In this embodiment, receive unit 90 is a minimum mean square error equalizer (MMSE) receiver requiring a receive processing matrix 108 based on channel matrix H to recover data 52. Hence, mode selection block 102 has the appropriate logic to compute matrix 108 as discussed below. Block 102 communicates matrix 108 to block 98 via a link.
Of course, a person of average skill in the art will be able to construct analogous relationships between other quality parameters QP of transmit signals TS transmitted from each of transmit antennas 72 and the receiver.
In accordance with the method of the invention, a threshold value QPth is assigned to quality parameter QP. The assignment of the threshold is based on the desired quality of receive signals RS. Conveniently, QPth is the minimum threshold at which receive signals RS can be re-converted into data 52 by block 98 at an acceptable error rate given the mode (coding rate and modulation of data 52 employed by spatial multiplexing block 56 of transmit unit 50). For example, the assignment can be based on a desired bit-error-rate (BER) of received data 52. Alternatively, other error rates such as packet error rates or symbol error rates of data 52 can be used to characterize the quality of receive signals RS. A person of average skill in the art is familiar with these characterizations and criteria for their selection.
and β z = 3 2  ( Z - 1 ) .
Selecting a minimum acceptable BERi at receive unit 90 given the mode thus yields an SINRi value to be used as threshold value SINRth. It should be noted that this holds for uncoded schemes, i.e., when no additional coding such as error coding is imposed on data 52. In the event such coding is used there is generally a coding gain which will vary SINRth, as will be appreciated by a person skilled in the art.
SINRth is used by mode selection block 102 to identify sub-descriptors of channel 22 which do not meet threshold SINRth. In this embodiment the sub-descriptors of channel 22 are sub-matrices hi of channel matrix H, as shown in FIG. 6. One sub-matrix hi, i=1 . . . M, is associated with each transmit antenna Ti, i=1 . . . M, of transmit antennas 72. The schematic of FIG. 6 illustrates a case where for all sub-matrices hi quality parameter QP exceeds threshold QPth with the exception of sub-matrix hj. In the present embodiment QP is SINR and thus SINRj<SINRth.
According to the method of the invention, transmit antenna Tj corresponding to sub-matrix hj is deactivated. In fact, transmit unit 50 is shown in FIG. 3 with antenna Tj deactivated, i.e., no transmit signals TS are transmitted from antenna Tj. This deactivation of one or more transmitting antennas Ti will generally improve and not worsen the quality parameter QP, in this case SINR, for the remaining transmitting antennas.
FIG. 7 illustrates how mode selection block 102 implements the deactivation decision. Channel matrix H, QP and QPth are received by a comparison block 110 where QP values for each sub-matrix hi are compared with QPth given the selected mode (see FIG. 6). Comparison block 110 identifies which of sub-matrices hi has a QPi, less than QPth and removes this sub-matrix, in the present embodiment sub-matrix hj, since QPj<QPth, from channel matrix H. Removal of sub-matrix hj from channel matrix H produces a subset channel matrix H′. Comparison block 110 recomputes QPi for each sub-matrix hi corresponding to transmit antenna Ti in subset matrix H′. Conveniently, recomputed QPi of sub-matrices hi of subset channel matrix H′ are compared with adjusted QPth. For example, recomputed QPi are compared with QPth required for particular modes to determine in which of those modes the corresponding antennas Ti should transmit. Advantageously, the mode whose required QPth is closest in value to the recalculated QPi is selected for data 52 transmitted from corresponding transmit antenna Ti.
Block 110 also passes subset channel matrix H′ to a computing block 112. Computing block 112 calculates the processing matrix 108 or optimal receiver Ropt and sends Ropt to block 98 for receive processing.
When all transmit antennas Ti meet threshold QPth of a different mode then employed at the time, e.g., a mode with a higher throughput, then this higher throughput mode is selected by comparison block 110. When a sub-matrix hj indicates that the corresponding transmit antenna Tj no longer meets QPth, then that antenna is deactivated and the mode is fed back to transmit unit 50. In this manner, transmission of data 52 can be optimized for highest throughput at the set QPth.
In fact, flow chart of FIG. 8 shows an embodiment of the method for achieving highest throughput a mode number # with corresponding threshold QPth-#. Initially, i is set equal to the number of transmit antennas Ti, i=M, such that k=M. Then, optimal receiver Ropt is computed as well as the values QPi for all sub-matrices hi. For convenience, antennas Ti and their corresponding sub-matrices hi are arranged in descending order of QPi. A mapping of this re-arranged or ordered set to the original order of sub-matrices hi and corresponding transmit antennas Ti is maintained for administrative purposes.
In the next step, each QPi is compared with a lowest threshold QPth-#. For example, lowest threshold QPth-# can be equal to the threshold for the lowest throughput acceptable mode #. When a QPi does not meet this lowest threshold QPth-#, the corresponding sub-matrix hi is removed from channel matrix H to produce subset channel matrix H′. With the same action the corresponding antenna Ti is designated for deactivation. After removal of sub-matrix hi the values of QPi are re-computed and the comparison repeated, until subset channel matrix H′ contains only sub-matrices hi which have QPi higher than QPth-# It should be noted that more than one sub-matrix hi can be removed at a time.
Once the final subset channel matrix H′ is obtained it is sent to the second branch in the flow chart of FIG. 8 to determine the best modes to use for transmission from the remaining antennas. The number of data streams k is set to the number of remaining sub-matrices hi, i=k. Then, in a recursive loop process, the best mode number for each antenna is determined by direct comparison of QPk with QPth-# required for that mode #. The mode # for which the comparison yields the closest match is selected for transmission from corresponding antenna #. Conveniently, the antenna # and mode # are ordered pairwise in a table for feedback to the transmit unit. Before feedback, the table is arranged to agree with the updated mapping of antenna # which was performed to arrange sub-matrices hi in descending order of QPi.
It should be noted, that comparison block 110 can re-set or adjust lowest QPth-#. For example, when data 52 is not very sensitive (e.g., voice) lowest QPth-# can be lowered and when data 52 is sensitive lowest threshold QPth-# can be raised. In fact, the setting of lowest QPth-# depends on the type of data 52 and other parameters well-known in the art of data processing.
Comparison block 110 can repeat the steps of identifying individual or even groups or sets of sub-matrices hi falling below lowest QPth-# and deactivate the corresponding antenna or antennas among transmit antennas 72. Of course, when channel 22 is very high quality, no transmit antennas 72 may need to be deactivated.
In general, the time period within which the above computations for antenna deactivation should be repeated should be shorter than the coherence time of channel 22.
In another embodiment, transmit unit 50 receiving feedback of channel information, whether using TDD or simple feedback, could make the selection of antenna or antennas to deactivate on its own. This alternative approach would be convenient when receive unit 90 does not have sufficient resources or power to make the comparisons between the values of QPi and QPth. Of course, transmit unit 50 would then contain all the corresponding computation and decision-making blocks, specifically mode selection block 102, contained in receive unit 90 as described above.
In an alternative embodiment shown in FIG. 9, the method of invention is employed in a communications system 200 using spatial-multiplexing. System 200 has several base transceiver stations (BTS), of which two 204, 206 are shown. BTS 204, 206 are equipped with transmit antenna arrays 208, 210 respectively for sending transmit signals to receive unit 212. It should be noted, however, that a combination of BTS with single transmit antennas can be used as long as spatial multiplexing is employed.
Receive unit 212 sets a threshold QPth and identifies among the sub-descriptors of a descriptor of channel 22, e.g., hi matrices of channel matrix H, one or more sub-descriptors which do not meet threshold QPth in the selected mode. As described above, receive unit 212 can adjust threshold QPth, in particular, it can adjust threshold QPth based on the desired mode. Receive unit 212 then determines a final selection which transmit antennas of transmit antenna arrays 208, 210 should be deactivated. Additionally, receive unit 212 determines which modes should be used by the remaining active transmit antennas of arrays 208, 210. It should be noted that under certain circumstances receive unit 212 may determine that one of base stations 204, 206 should not be transmitting any transmit signals to receive unit 212 at all.
The selection of antennas and modes is fed back from receive unit 212 to BTS 204, 206. In particular, a control logic, in this embodiment a controller 202 receives the feedback from receive unit 212. Controller 202 can be a central control unit supervising the operation of BTS 204, 206 and any other BTS of communication system 200. Alternatively, control logic can consist of separate control units as indicated in dashed lines.
In another embodiment of the invention, the descriptor of channel 22 is a channel matrix filter and sub-descriptors are sub-matrix filters . Conveniently, channel matrix filter is used as descriptor when inter-symbol interference (ISI) is present due to broadly varying times of arrival or under other adverse conditions associated with delay spread. A person of average skill in the art is familiar with channel matrix filters , their construction and their use in reconstructing transmitted data under such channel conditions.
where s k is the signal vector at time k, n k is the noise vector at time k, x k is the received signal vector at time k, q is the number of received signal snap shots used for processing (also referred to as the number of equalizer taps), L is the number of delay elements in the channel and p≧q+L. As is clear from the explicit system equation, channel matrix filter actually consists of a number of channel matrices H, each of which is an N×M matrix, where N is the number of receive antennas at the receive unit and M is the number of transmit antennas.
Therefore, channel matrix filter H is actually qN×pM. In fact, M is the total number of antennas from which receive unit is meant to receive spatially multiplexed signals. As discussed above, these transmit antennas can belong to separate BTS, include single transmit antennas or transmit antennas which are part of any suitable transmit antenna array.
where i=1, 2, . . . M. At this point the SNR values for each transmit antenna can be compared with a threshold SNRth. The remaining steps leading to the selection of which transmit antenna should be deactivated are analogous to those described above.
The method of invention can also be used in multi-carrier systems using spatial multiplexing. In these types of communication systems several sub-carrier frequencies or sub-carrier tones are transmitted from each transmit antenna. Each of these sub-carrier tones experiences a different channel in propagating from the transmit unit to the receive unit. Hence, each transmit antenna has associated with it a group of sub-descriptors; one for each sub-carrier tone.
In this case each transmit antenna and its associated sub-descriptor will yield a different quality parameter QP at the different sub-carrier frequencies. In other words, data transmitted from a transmit antenna Tj on a first sub-carrier tone ST1 will exhibit a quality parameter QPj1 different from a quality parameter QPj2 for data transmitted from the same transmit antenna Tj on a second sub-carrier tone ST2. Hence, the selection of which transmit antenna to deactivate in this case is made based on the average quality parameter QP j for the group of sub-descriptors associated with that antenna. With this change, the method of invention can be employed in multi-carrier systems as described for non multi-carrier communication systems.
The method of the invention can be used in soft hand-off between base stations in cellular systems. Alternatively, partial hand-offs or gradual hand-offs between base stations can be implemented, depending on antenna selection. In fixed wireless systems the user device can operate by receiving signals from a selection of antennas belonging to different base stations at all times. Also, in the case of fixed wireless devices there may be cases where the channel does not change appreciably over time. In this case, once the antenna selection is made, no feedback may be required.
It will be clear to one skilled in the art that the above embodiments may be altered in many ways without departing from the scope of the invention. Accordingly, the scope of the invention should be determined by the following claims and their legal equivalents.
e) deactivating among said transmit antennas an antenna associated with said sub-descriptor, wherein said channel descriptor is a channel matrix H and said sub-descriptors are sub-matrices hi, and said sub-descriptor is a sub-matrix j of the channel matrix, and wherein said deactivating comprises removing at least one of the sub-matrix hj to obtain a subset channel matrix H′.
2. The method of claim 1, wherein said quality parameter is selected from a group consisting of signal-to-interference and noise ratio, signal-to-noise ratio, and power level.
3. The method of claim 1, wherein said spatial multiplexed communication employs a number of sub-carrier tones associating groups of said sub-descriptors with said transmit antennas.
4. The method of claim 3, wherein said identifying comprises computing an average quality parameter for said groups of sub-descriptors and identifying among said groups of sub-descriptors a group of sub-descriptors not meeting said threshold, and said deactivating comprises deactivating among said transmit antennas an antenna associated with said group of sub-descriptors.
5. The method of claim 1, further comprising repeating said identifying and said deactivating.
6. The method of claim 1, further comprising adjusting said threshold.
7. The method of claim 1, wherein said data is coded and modulated in accordance with a selected mode.
8. The method of claim 7, wherein said mode comprises a predetermined coding rate and modulation.
9. The method of claim 7, wherein said threshold is assigned based on said selected mode.
10. The method of claim 7, wherein said selected mode is based on said quality parameter.
11. The method of claim 7, wherein said selected mode is fed back to said transmit unit.
12. The method of claim 1, wherein said receive unit is selected from the group consisting of maximum likelihood receivers, zero forcing equalizer receivers, successive cancellation receivers and minimum mean square error equalizer receivers.
e) deactivating among said transmit antennas, antennas associated with said set of sub-descriptors by removing said set of sub-matrix filters hi from said channel matrix filter H to obtain a subset channel matrix filter H′.
14. The method of claim 13, wherein said quality parameter is selected from the group consisting of signal-to-interference and noise ratio, signal-to-noise ratio, and power level.
15. The method of claim 13, further comprising repeating said identifying and said deactivating.
16. The method of claim 13, wherein said spatial multiplexed communication employs a number of sub-carrier tones associating groups of said sub-descriptors with said transmit antennas.
17. The method of claim 16, wherein said identifying comprises computing an average quality parameter for said groups of sub-descriptors and identifying among said groups of sub-descriptors a set of groups of sub-descriptors not meeting said threshold, and said deactivating comprises deactivating among said transmit antennas a set of antennas associated with said set of groups of sub-descriptors.
18. The method of claim 13, further comprising adjusting said threshold.
19. The method of claim 13, wherein said data is coded and modulated in accordance with a selected mode.
20. The method of claim 19, wherein said mode comprises a predetermined coding rate and modulation.
21. The method of claim 19, wherein said threshold is assigned based on said selected mode.
22. The method of claim 19, wherein said selected mode is based on said quality parameter.
23. The method of claim 19, wherein said selected mode is fed back to said transmit unit.
24. The method of claim 13, wherein said receive unit is selected from the group consisting of maximum likelihood receivers, zero forcing equalizer receivers, successive cancellation receivers and minimum mean square error equalizer receivers.
e) deactivating among said transmit antennas an antenna associated with said sub-descriptor, said deactivating including removing said sub-matrix hj from said channel matrix H to obtain a subset channel matrix H′.
26. The method of claim 25, wherein said quality parameter is selected from a group consisting of signal-to-interference and noise ratio, signal-to-noise ratio, and power level.
27. The method of claim 25, wherein said spatial multiplexed communication employs a number of sub-carrier tones associating groups of said sub-descriptors with said transmit antennas.
28. The method of claim 27, wherein said identifying comprises computing an average quality parameter for said groups of sub-descriptors and identifying among said groups of sub-descriptors a group of sub-descriptors not meeting said threshold, and said deactivating comprises deactivating among said transmit antennas an antenna associated with said group of sub-descriptors.
29. The method of claim 25, further comprising repeating said identifying and said deactivating.
30. The method of claim 25, further comprising adjusting said threshold.
31. The method of claim 25, wherein said selected mode is based on said quality parameter.
32. The method of claim 25, wherein said receive unit is selected from the group consisting of maximum likelihood receivers, zero forcing equalizer receivers, successive cancellation receivers and minimum mean square error equalizer receivers.
c) a feedback unit for sending feedback related to said at least one sub-descriptor to said transmit unit; and said transmit unit comprising a control logic for receiving said feedback and deactivating among said transmit antennas, antennas associated with said at least one sub-descriptor, said deactivating including removing said sub-matrix hj from said channel matrix H to obtain a subset channel matrix H′.
34. The system of claim 33, wherein said transmit unit further comprises a spatial multiplexing block connected to said control logic for coding and multiplexing said data.
35. The system of claim 33, wherein said transmit unit further comprises a switching unit for deactivating said antennas.
36. The system of claim 33, wherein said receive unit is selected from the group consisting of maximum likelihood receivers, zero forcing equalizer receivers, successive cancellation receivers and minimum mean square error equalizer receivers.
c) a feedback unit for sending feedback related to said at least one sub-descriptor to said transmit unit; and said number of transceivers comprising a control logic for receiving said feedback and deactivating among said transmit antennas, antennas associated with said at least one sub-descriptor, said deactivating including removing said sub-matrix hj from said channel matrix H to obtain a subset channel matrix H′.
38. The system of claim 37, wherein said transceivers further comprise spatial multiplexing blocks for coding and multiplexing said data.
39. The system of claim 37, wherein said transceivers further comprise switching units for deactivating said antennas.
40. The system of claim 37, wherein said receive unit is selected from the group consisting of maximum likelihood receivers, zero forcing equalizer receivers, successive cancellation receivers and minimum mean square error equalizer receivers.
41. The system of claim 37, wherein said control logic comprises a number of control units.
42. The system of claim 41, wherein each of said transceivers has one of said control units.
Paulraj, A., Taxonomy of space-time processing for wireless networks, IEE Proc-Radar Sonar Navig., vol. 145, No. 1, Feb. 1998.


The lens in Beta magnifiers produces sharp, high contrast images free of distortion, colour-fringing, and fully usable from edge to edge. The folding case protects the lens when not in use.
The colour-corrected lenses used in Beta magnifiers is only one of the reasons for their extreme popularity, especially in the printing industry where it is possible to clearly recognize the individual halftone dots at a distance of 20 cms. The increased distance between the eye and lens prevents shadows falling on the object being inspected and provides long relief on the eye.
The optical system is both achromatic and aplanatic consisting of three lenses subdivided into two groups with anti-reflection coating.
The lens in the most popular 12x model contradicts the old compromise that the field of view is automatically reduced as magnification factor increases. In spite of 12x magnification the lens has a 15 mm field of view when positioned against the eye. At a distance of 10 cms it is still approx. 6 mm and at 20 cms approx. 5 mm.
The lens is on a threaded barrel for adjustable focus. A locking ring prevents accidental change of the focus setting.
The lens can be focused initially by moving it close to the eye and then turning the focus ring to the right distance. The lens can then be fixed with the counter-ring present on the thread. Then hold the lens at the optimum distance for the user or move your eye away until the desired distance is reached.
An optional LED illumination unit (LED-MAG-12) is available for the 12x model which can be inserted into the recess in the lens mount when the case is open. The cover can then be closed again. This additional illumination eliminates all dark spots.
The Beta range of magnifiers include 9 different models with 3 body designs and 3 levels of magnification. The models MAG, VIEW and SWING share the same lens types and differ only in terms of body design; each model is available with 10x, 12x and 20x magnifications.


text:
Q: How to convert string to integer in UNIX shelll I have d1="11" and d2="07". I want to convert d1 and d2 to integers and perform d1-d2. How do I do this in UNIX?
d1 - d2 currently returns "11-07" as result for me.

A: An answer that is not limited to the OP's case
The title of the question leads people here, so I decided to answer that question for everyone else since the OP's described case was so limited.
TL;DR
I finally settled on writing a function.

*

*If you want 0 in case of non-int:

int(){ printf '%d' ${1:-} 2>/dev/null || :; }

*If you want [empty_string] in case of non-int:

int(){ expr 0 + ${1:-} 2>/dev/null||:; }

*If you want find the first int or [empty_string]:

int(){ expr ${1:-} : '[^0-9]*\([0-9]*\)' 2>/dev/null||:; }

*If you want find the first int or 0:

# This is a combination of numbers 1 and 2
int(){ expr ${1:-} : '[^0-9]*\([0-9]*\)' 2>/dev/null||:; }

If you want to get a non-zero status code on non-int, remove the ||: (aka or true) but leave the ;
Tests
# Wrapped in parens to call a subprocess and not `set` options in the main bash process
# In other words, you can literally copy-paste this code block into your shell to test
( set -eu;
    tests=( 4 "5" "6foo" "bar7" "foo8.9bar" "baz" " " "" )
    test(){ echo; type int; for test in "${tests[@]}"; do echo "got '$(int $test)' from '$test'"; done; echo "got '$(int)' with no argument"; }

    int(){ printf '%d' ${1:-} 2>/dev/null||:; };
    test

    int(){ expr 0 + ${1:-} 2>/dev/null||:; }
    test

    int(){ expr ${1:-} : '[^0-9]*\([0-9]*\)' 2>/dev/null||:; }
    test

    int(){ printf '%d' $(expr ${1:-} : '[^0-9]*\([0-9]*\)' 2>/dev/null)||:; }
    test

    # unexpected inconsistent results from `bc`
    int(){ bc<<<"${1:-}" 2>/dev/null||:; }
    test
)

Test output
int is a function
int ()
{
    printf '%d' ${1:-} 2> /dev/null || :
}
got '4' from '4'
got '5' from '5'
got '0' from '6foo'
got '0' from 'bar7'
got '0' from 'foo8.9bar'
got '0' from 'baz'
got '0' from ' '
got '0' from ''
got '0' with no argument

int is a function
int ()
{
    expr 0 + ${1:-} 2> /dev/null || :
}
got '4' from '4'
got '5' from '5'
got '' from '6foo'
got '' from 'bar7'
got '' from 'foo8.9bar'
got '' from 'baz'
got '' from ' '
got '' from ''
got '' with no argument

int is a function
int ()
{
    expr ${1:-} : '[^0-9]*\([0-9]*\)' 2> /dev/null || :
}
got '4' from '4'
got '5' from '5'
got '6' from '6foo'
got '7' from 'bar7'
got '8' from 'foo8.9bar'
got '' from 'baz'
got '' from ' '
got '' from ''
got '' with no argument

int is a function
int ()
{
    printf '%d' $(expr ${1:-} : '[^0-9]*\([0-9]*\)' 2>/dev/null) || :
}
got '4' from '4'
got '5' from '5'
got '6' from '6foo'
got '7' from 'bar7'
got '8' from 'foo8.9bar'
got '0' from 'baz'
got '0' from ' '
got '0' from ''
got '0' with no argument

int is a function
int ()
{
    bc <<< "${1:-}" 2> /dev/null || :
}
got '4' from '4'
got '5' from '5'
got '' from '6foo'
got '0' from 'bar7'
got '' from 'foo8.9bar'
got '0' from 'baz'
got '' from ' '
got '' from ''
got '' with no argument

Note
I got sent down this rabbit hole because the accepted answer is not compatible with set -o nounset (aka set -u)
# This works
$ ( number="3"; string="foo"; echo $((number)) $((string)); )
3 0

# This doesn't
$ ( set -u; number="3"; string="foo"; echo $((number)) $((string)); )
-bash: foo: unbound variable

A: The standard solution:
 expr $d1 - $d2

You can also do:
echo $(( d1 - d2 ))

but beware that this will treat 07 as an octal number!  (so 07 is the same as 7, but 010 is different than 10).

A: Any of these will work from the shell command line. bc is probably your most straight forward solution though.
Using bc:
$ echo "$d1 - $d2" | bc

Using awk:
$ echo $d1 $d2 | awk '{print $1 - $2}'

Using perl:
$ perl -E "say $d1 - $d2"

Using Python:
$ python -c "print $d1 - $d2"

all return
4

A: let d=d1-d2;echo $d;

This should help.

A: Use this:
#include <stdlib.h>
#include <string.h>

int main()
{
    const char *d1 = "11";
    int d1int = atoi(d1);
    printf("d1 = %d\n", d1);
    return 0;
}

etc.

redpajama_set_name: RedPajamaStackExchange


Investor Services Asia along with the Rainforest Rescue International (RRI) has taken the initiative for the fourth stage of the project in Vavuniya. Under this stage, the database of beneficiaries has been widened with 50 more beneficiaries who are from 2 new villages. Encouraging their cultivation as a source of income, new plants are also to be distributed among the households. These plants include Lemon grass, Papaya, Banana, Ginger, Turmeric, Yams, Areca nut and Beatle leaves. In addition to that, well cleaning and de-silting activities are also to be carried out in this phase of the project.


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Search OPG's renewable generation job opportunities below or join our Talent Community to receive alerts on new openings.


text:
WEG held the second edition of Six Sigma Summit
The event took place on 19, 20 and 10/21/22, and was attended by more than 1400 employees, large companies and institutions
On October 19, 20 and 21, 2022, WEG held the second edition of the SIX SIGMA SUMMIT online, an internal event that aims to disseminate the results obtained by WEG's Six Sigma Program in Brazil and abroad, in addition to share knowledge through project presentations, workshops, discussion forums and lectures with experts from partner companies and educational institutions.
According to Vitor Marcon, Quality System and Certifications Department Manager at WEG, "It was 3 days with a lot of information and very positive aspects regarding the Six Sigma culture and the exchange of experiences among all units of the WEG group, in addition to synergy with the company's other programs and methodologies."
The event was attended by more than 1,400 employees from all WEG business units in Brazil, Mexico, Portugal, China, United States, India, Austria and Germany, with the external participation of the Polytechnic University of São Paulo (Poli- USP) and the companies Bayer, Whirlpool, Santander and Magma.
In addition to sharing knowledge and results, the event helped to keep people engaged in using the methodology with a focus on improving the performance of WEG products and processes, also encouraging benchmarking between WEG units and observance of the applicability of these practices by other companies and institutions.
About WEG's Six Sigma Program:
The Six Sigma Methodology is a set of techniques and tools with the purpose to systematically improve processes and products, acting in compliance and reliability. Its approach is focused on customer satisfaction and the pursuit of Competitiveness, Quality, Sustainability and Technology.
Since 2015, WEG's Six Sigma Program has been active in all the company's business unit (Motors, Energy, Automation, Transformers and Coatings) and operates globally, where it trained around 1,900 employees to apply the Six Sigma methodology in the Master Black, Black Belt, Green Belt and Yellow Belt levels, in addition to training more than 800 managers in the Six Sigma Champion modality.
In the same period, more than 1,400 improvement projects were carried out, increasing the quality of products and processes, reducing waste and contributing to the sustainability of the business.
During 2022, 297 projects were implemented in the most diverse areas of the company. This year, WEG also invested in the training of its suppliers, with the Six Sigma for Suppliers program, where employees from 10 companies were trained in the Six Sigma methodology at a Green Belt level, carried out their projects for certification and obtained results that will collaborate to improve the quality, efficiency, productivity and competitiveness generating benefits throughout the chain.
Curso de Qualificação Profissional de Operadores de Produção (QPOP) ofertado pela WEG completa 20 anos
Desde o início do programa, em 2002, mais de 21.500 profissionais já foram capacitados
WEG invests in employees qualification through Six Sigma methodology
Since 2015, over 1870 employees have been trained and more than 2400 improvement projects were implemented using the Six Sigma methodology, tools and concepts
WATT DRIVE ANTRIEBSTECHNIK GMBH
Wöllersdorfer Straße 68 Markt Piesting - 2753 - Niederösterreich / Austria
Phone: + 43 2633 4040
Email: info-at@weg.net
Imprint | Privacy Notice | Cookie Statement | Terms and Conditions | RSS | © 2023 WEG. All rights reserved.

redpajama_set_name: RedPajamaCommonCrawl


Michael Sullivan is a local musician that grew up listening to everything from the Beatles to Motown.
Today, as a singer/songwriter he performs all styles from Tom Petty to the Everly Brothers. You will also hear songs from Amos Lee and David Gray. Michael also enjoys writing songs, so he'll plug an original now and than.
Stop by for a beverage, enjoy a made to order wood fired pizza, and listen to Michael.
Wood fired pizza service 4 pm to 8 pm.


text:
Q: Using swig Python wrapper: argument 2 of type 'std::unordered_set< std::string > const &' I am updating an old project using (parent project of) the Python package coqui_stt_ctcdecoder generated from C++ using SWIG. Some parameter types in some methods have changed. I am stuck with the method Scorer::fill_dictionary that takes const std::unordered_set<std::string>&  as an argument in C++. In the old Python code a list of bytes is passed, but that no longer works, as well as a set. I have no idea what type to put there. The error is
Traceback (most recent call last):
  File "/mnt/d/shared/speech/dsalign/STT-align/align/align.py", line 693, in <module>
    main()
  File "/mnt/d/shared/speech/dsalign/STT-align/align/align.py", line 451, in main
    create_bundle(alphabet_path, scorer_path + '.' + 'lm.binary', scorer_path + '.' + 'vocab-500000.txt', scorer_path, False, 0.931289039105002, 1.1834137581510284)
  File "/mnt/d/shared/speech/dsalign/STT-align/align/generate_package.py", line 75, in create_bundle
    scorer.fill_dictionary(words)
  File "/mnt/d/shared/speech/dsalign/STT-align/venv/lib/python3.10/site-packages/coqui_stt_ctcdecoder/swigwrapper.py", line 1269, in fill_dictionary
    return _swigwrapper.Scorer_fill_dictionary(self, vocabulary)
TypeError: in method 'Scorer_fill_dictionary', argument 2 of type 'std::unordered_set< std::string > const &'

EDIT: I have tried a list and a set of str and bytes, all with the above exception. I have used Python 3.8 on Windows and WSL.

A: SWIG includes support for std::unordered_set, but note that the interface oddly doesn't accept Python set objects.  tuple and list work, however.
Tested example:
test.i
%module test

// Code injected into wrapper
%{
#include <iostream>
#include <string>
#include <unordered_set>

// Function using the parameter type from OP error message
void func(std::unordered_set<std::string> const &string_set) {
    for(auto& s : string_set)
        std::cout << s << std::endl;
}
%}

// SWIG support for templates
%include <std_unordered_set.i>
%include <std_string.i>
// Must instantiate the specific template used
%template(string_set) std::unordered_set<std::string>;

// Tell SWIG to wrap the function
void func(std::unordered_set<std::string> const &string_set);

Demo:
>>> import test
>>> test.func(['abc','def','abc','ghi'])  # list works
abc
def
ghi
>>> s = test.string_set(['aaa','bbb','ccc','aaa','bbb'])
>>> test.func(s)
aaa
bbb
ccc
>>> s = test.string_set(('aaa','bbb','ccc','aaa','bbb')) # tuple works
>>> list(s)
['aaa', 'bbb', 'ccc']
>>> test.func({'abc','def'})  # set doesn't work
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\test.py", line 194, in func
    return _test.func(string_set)
TypeError: in method 'func', argument 1 of type 'std::unordered_set< std::string,std::hash< std::string >,std::equal_to< std::string >,std::allocator< std::string > > const &'


Do you have a reluctant reader? Would your daughter rather be playing with Barbie then sitting down to read a book? Reading is an important part of a child's education and as parents; it is up to you to get your child to read. Barbie Books are a great way to put the fun back into reading for girls of all ages.
For the youngest Barbie fans, Barbie Board Books are a great choice, while the older more experienced readers will find that the Barbie Chapter Books provide a great read. Want your two Barbie fans to read together look at our huge selection of Barbie Picture Books.
Barbie Book, Barbie Coloring Book, Barbie Sticker Book, Barbie Story Book, Barbie Children's Book, Barbie Book for Children, Barbie Books for Toddlers, Books about Barbie.


The transport and logistics sector plays a major role in the global economy. In the UK, it employs over 2.5 million people with the logistics industry by itself worth over £75 billion to the country. Although affected by the economic downturn over the past few years, the sector has recovered well and businesses in the sector are looking for new opportunities.
Boyes Turner draws on its knowledge, experience and long-standing interest in the transport and logistics industry to support clients in aviation services, supply chain and logistics, engineering and manufacturing.
Based in the heart of the Thames Valley and on the doorstep of one of the busiest airports in the world, Boyes Turner continues to grow its services in this dynamic and fast-paced sector.
Whether it is the design and manufacture of aircraft parts, business process outsourcing, implementation of airport IT systems or aircraft maintenance, so much of what makes this vibrant industry tick goes on behind the scenes. Boyes Turner focuses on these market players, providing tailored advice and assistance from lawyers who understand the jargon, the pressures and the commercial issues facing those who operate in the aviation sector.
The need for accurate, timely and efficient distribution management to meet the demands not only of the consumer retail market place, including e-commerce sales but also business-to-business sales has never been greater.
Boyes Turner has a wealth of experience in advising clients on effective resource management - whether that is staffing, vehicle use or warehouse floor space, the negotiation of warehousing and distribution agreements and the sensitive issues of service provision changes and service levels as well as handling in relation to storage, handling and delivery of goods.
With a client base ranging from waste water management to healthcare and specialist pharma products and consumer goods distribution, the firm is able to zero in on the key issues, providing effective commercial advice.
Boyes Turner plays an active role in advising engineering and manufacturing companies in the Thames Valley and beyond. The firm's experience covers oil and gas, automotive, aviation, military and other precision engineering and manufacturing activities.
Boyes Turner takes time to understand clients' businesses in order to grasp the key drivers on legal strategy and the nuts and bolts of everyday delivery. The aim is to help them make the very best of their opportunities and to continue to grow whilst protecting their valuable intellectual property and other assets in an ever more competitive and demanding world.
15/05/2019 - Following our Autumn European Webinar Series which focussed on disciplinary procedures our second mini-series will focus on the issues of individual and collective redundancies across a number of European Countries.
22/05/2019 - Following our Autumn European Webinar Series which focussed on disciplinary procedures our second mini-series will focus on the issues of individual and collective redundancies across a number of European Countries.


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Home News Alta Zinc scoping study confirms Gorno as potentially viable development with considerable...
Alta Zinc scoping study confirms Gorno as potentially viable development with considerable upside po
Alta Zinc Ltd (ASX:AZI)'s scoping study has confirmed that the Gorno Zinc-Lead-Silver Project in northern Italy is potentially a commercially viable underground development opportunity, with considerable upside potential.
The initial scoping study by CSA Global, estimated an approximate total production target of 6.0 million tonnes containing 77% indicated and 23% inferred mineral resources at or above a cut-off grade of 3.5% zinc equivalent at an annual mining rate of 800,000 tonnes over the proposed nine-year Life of Mine (LOM).
It has also identified pre-production capital costs of US$114 million, excluding pre-development capital of around A$5.2 million.
The LOM target is estimated to be about 630,000 dry metric tonnes (dmt) of zinc concentrate (63% zinc) and 108,000 dmt of lead-silver concentrate (76% lead and 740 g/t silver).
Planned drill programs to test the extensions of the current mineral resource and surrounding exploration target area(s) are likely to extend the life of mine beyond the initial nine-year period.
Next stage of feasibility studies
The study recommends proceeding to the next stage of feasibility studies.
In accordance with the recommendations, the company plans to commence further metallurgical test-work in early 2022 in parallel with ongoing exploration and resource drilling as part of a definitive feasibility study (DFS) with results expected by the end of 2022.
The current study indicates that pre-development work will start in 2022 with a construction decision mid-2023 and first production early in the second half of 2024.
These timings will be further evaluated and refined in the upcoming DFS.
The scoping study is based on the mineral resource estimate (MRE) of 7.79 million tonnes at 6.8% zinc, 1.8% lead and 32 g/t silver.
Best-in-class modern underground mine?
Alta Zinc manging director Geraint Harris said: "This scoping study provides an initial evaluation of the Gorno Project that considered several possible options to define a project path to maximise project economics, minimise environmental and social impacts and deliver maximum shareholder returns.
"In my opinion, Gorno is set to become a best-in-class modern underground mine with a minimal surface and environmental footprint.
"It will efficiently extract a high value mineralisation and convert it into one of the highest grade and cleanest zinc and lead concentrate products available globally.
Initial economic evaluations compelling
He continued: "The initial economic evaluations are compelling and provide substantial justification for the advancement of the asset, as well as highlighting areas where we can further grow the resource base and refine our strategy for progressing the asset throughout 2022.
"We take confidence from the study knowing that the robust NPV and IRR was based on a detailed analysis from highly experienced consultants, with commodity price assumptions significantly below current spot levels.
"There are opportunities for further resource extension and optimisation, with the upside potential for increasing mine life and possibly throughput.
"The company has achieved rapid resource growth and exploration success in the last 24 months notwithstanding challenges faced with COVID-19 both globally and within Italy and we remain committed to continuing an extensive program of exploration and development activities across our 100%-owned Italian tenement package.
Scoping study results
The scoping study delivered the following key results:
? LOM production target is indicated to be 6.04 million tonnes at 7.1% zinc, 1.9% lead and 31 g/t silver, recovering 396,000 tonnes zinc, 81,800 tonnes lead and 3.4 million ounces silver (comprising of 77% indicated mineral resources and 23% inferred resources)
LOM concentrate production of zinc: 630,000 dmt (63% zinc) and lead: 108,000 dmt lead/silver concentrate (76% lead and 740 g/t silver); and
Annual mine production rate of 800,000 tonnes and processing rate of 520,000 tonnes.
? Mine life of nine years (plus a 15-18 months construction period) averaging around US$67 million (A$93 million) of annual free cash-flow during peak production (years 2026 to 2031).
? Among the lowest projected cost for global primary zinc producers
Cash cost mining, processing, G&A, transport, treatment charges/refining charges (TC/RC), royalty of US$0.54/lb zinc equivalent (co-product convention); and
All-in sustaining cost (AISC) mining, processing, general & administration, transport, TC/RC, royalty, sustaining capex of US$0.60/lb zinc equivalent (co-product convention).
? Zinc metallurgical recovery of 93% (including ore sorter) with 80% of revenues from payable zinc.
? Estimated initial capital cost, US$114 million (+-35% accuracy) and LOM sustaining capital cost of US$42 million
Substantially de-risked initial underground capital includes 3,800 metres of re-used historical development, 890 metres of existing development being enlarged, 2,880 metres of new development and 400 metres of raise-boring;
Includes all-new processing equipment, underground crusher and conveyors, ore sorters, waste and concentrate loading facilities, train haulage, all surface and underground infrastructure;
Re-use of an existing modern factory building and infrastructure to house the processing plant and no surface tailings disposal or waste dumps required; and
Sustaining capital estimated at US$42 million (8% of operating cost).
? Positive financial metrics in the range of:
Post-tax net present value (NPV) of about US$211 million (A$288 million);
Post-tax internal rate of return (IRR) of around 50%; and
Payback period of around 3.5 years from final investment decision and about 2.5 years from first concentrate production.
? Significant expansion and upside potential beyond the scoping study
Ongoing exploration drilling will run in conjunction with the DFS, targeting further resources definition and growth expected from the defined Exploration Target estimated as an additional 17.4 million tonnes to 22 million tonnes at grades ranging between 8.5 and 10.4% zinc, 1.9 and 2.4% lead and 19 and 23 g/t silver from exploration to be undertaken in conjunction with next stage of study; and
Ongoing metallurgical test-work and flowsheet design will target processing performance, equipment sizing, maximising metallurgical recoveries and optimising concentrate economics.
The company will explore all financing and development options that are in the interests of maximising shareholder value.
Whilst no formal funding discussions have commenced, Alta Zinc has engaged with a number of financial institutions, who have expressed a high level of interest in being involved in the funding of the project.
It has also received indicative support from its major shareholder, Victor Smorgon Group (VSG), to support future funding requirements, however no binding commitment is currently in place.
To achieve the range of outcomes indicated in the study, pre-production funding of around A$152 million may be required.
Typical project development financing would involve a combination of debt and equity.
Alta has formed the view that there is a reasonable basis to believe that requisite future funding for development of the Gorno Project will be available when required.
This is based on the fact that:
? The study results indicate that the Gorno Project has scale and quality parameters that would be advantageous for future discussions with potential financiers and/or industry partners;
? The Gorno zinc and lead concentrate specifications are of exceptionally high grade. It is likely that the entire Gorno zinc production could be sold to smelters within Europe and the concentrates also meet Chinese import requirements for low levels of deleterious elements. Financing support is considered likely from smelters or metals traders requiring access to a supply of high grade, low iron concentrates to address the ongoing market shortage of adequate high-grade replacement tonnage since the Century mine closure in 2015;
? The company has achieved a strong track record of raising equity funds as and when required to further the exploration and evaluation of the Gorno Project. Global debt and equity finance availability for high-quality base metals projects remains robust; and
? Alta has a current market capitalisation of around A$25 million and no debt, and has an uncomplicated, clean corporate and capital structure. Alta owns 100% of the Gorno Project. These factors are expected to be highly attractive to potential financiers.
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Share this Story: Le Combat des livres kicks off with talk of independence and throwing books
Le Combat des livres kicks off with talk of independence and throwing books
Brendan Kelly • Montreal Gazette
The real hostilities only start on Tuesday when the first book is tossed overboard but there was still no shortage of drama on the first day of the all-star 2013 edition of Le Combat des livres . All five participants, including moi-meme, have previously appeared on the Radio-Canada books contest, which is the Franco version of Canada Reads.
Geneviève Guérard, the only femme amongst the five panelists, underlined that fact right at the start, a smart way to try to woo the three women on the five-member jury that will be voting books off the island Survivor-style beginning on Tuesday. Monday things were relatively subdued given that each of us were just introducing ourselves and our book choices – me talking up Heather O'Neill's raw masterwork Lullabies for Little Criminals (La Ballade de Baby en francais), former ballet star Guérard defending Jocelyne Saucier's Il pleuvait des oiseaux, ex-Premier Bernard Landry going to bat for Samuel Archibald's Arvida, bicultural singer-songwriter Thomas Hellman sticking up for Lawrence Hill's The Book of Negroes (Aminata in French), and comic Dominique Lévesque fighting for Éric Dupont's magical-realist epic La fiancée américaine.
Le Combat des livres kicks off with talk of independence and throwing books Back to video
But there was some sparring even in the early going. In the midst of my very first pitch, Guérard said she was so put off by the grimy portrait of humanity in La Ballade de Baby that she threw the book across the room in disgust. It reminded me of the moment on the fiercely-fought last day of the 2009 Combat when actor Emmanuel Bilodeau and I were duking it out and he said that some sections of Rawi Hage's De Niro's Game, the book I was defending, read like vomit on the page. Yikes! Apparently my book choices sometimes rub people the wrong way.
There was also much talk about independence from……M. Landry. (Eds. note: I'm shocked, truly shocked.) When my Scottish roots came up, he mentioned that perhaps my former home country might be becoming a sovereign nation. That led me to refer to a recent essay by Trainspotting author Irvine Welsh who suggested that Scottish independence might actually help the English better get a grip on their sense of identity.
Landry liked that one. He said he's happy to use words like 'independence' and 'nation' and said Irvine's argument is exactly what English-Canadians should understand – that Quebec independence will allow folks in the Rest of Canada (ROC) to get a better sense of their own identity.
Books being tossed around, debates about Quebec independence……it looks like it should be a fun week. Tune in – every day at 1 p.m. on La Première Chaine of Radio-Canada with host Marie-Louise Arsenault.


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Grid Brief
UK May Experience 3-Hour Rolling Blackouts In Winter // Energy Crisis American Style // EU Diplomat Admits to Russian Dependence
Emmet Penney
UK May Experience 3-Hour Rolling Blackouts In Winter
UK's National Grid has announced that if Russia cuts gas flows to Europe and the UK and Britain experiences a cold snap, Brits could experience a series of three-hour rolling blackouts.
"Such an event would mean consumers in different parts of the country being notified a day in advance of three-hour blocks of time during which their power would be cut off, in an effort to reduce total consumption by 5%," reports the Guardian. "The emergency plan would need to be approved by King Charles on the recommendation of the business secretary."
National Grid describes the possibility of such an event as "unlikely." National has called on five coal plants to meet its potential demand needs and is looking into "demand flexibility" programs to maintain grid stability in the case of an emergency.
"We're heading into winter in an unprecedented situation. Even during the cold war, the Soviet Union kept the gas flowing so it's very unpredictable," an industry insider told the Guardian.
Energy Crisis American Style
Natural gas prices are high--really high. According to Oilprice.com, "Prices of natural gas are trading about 94% higher than at the start of the year and 370% higher than the 2020 lows." That means higher bills for Americans who need gas to heat their homes, and gas to keep the lights on. If you have a heat pump you need electricity for both.
The uptick in natural gas prices will hit New England the hardest as the region is exposed to the global LNG market. As I wrote recently for The Spectator, "Despite its proximity to the Marcellus Shale Formation, the region lacks the pipeline infrastructure to import natural gas from it. The Jones Act, which bars foreign-owned vessels from delivering goods between US ports, has also hamstrung the region. New England's LNG import terminals cannot receive from the Gulf of Mexico's LNG export terminals because while the United States produces the most LNG in the world, it does not make LNG tankers. So, New Englanders will have to compete with Europe and Asia for pricey LNG to light and heat their homes this winter. That'll be painful--natural gas is 53% of the New England grid's resource mix."
Natural gas markets look to remain tight as the weather gets colder. Waning flows from Russia to Europe and massive exports from America to Europe appear to be durable near-term trends.
"With US gas storage finishing this summer well below average levels, and lower than what we expected previously owing to strong power burns, we believe there is a mispricing of this upside risk to gas prices in the near-term," Goldman Sach commodity analyst Samantha Dart recently wrote to clients.
Now that OPEC+ has cut production and no one seems to be stepping up to increase supply, gasoline prices may rise, too, hitting Americans on two fronts as the mid-term elections approach.
EU Diplomat Admits to Russian Dependence
At the Annual EU Ambassadors Conference on Monday, High Representative Josep Borrell had sober words for his colleagues: the world they once knew is over and a new political and economic reality has emerged to take its place.
What was the old world? "You - the United States - take care of our security. You - China and Russia – provided the basis of our prosperity," Borrell said. "This is a world that is no longer there."
He pointed out that the insurgent European right has been democratically gaining in the EU as this old world has disappeared. The new right, Borrell said, "is the choice of the people, it is not an imposition from any power. It is the people who go and vote here and there. I am not going to blame anyone, but you have in mind what I am talking about."
These comments are remarkably candid. On the horizon, he sees three major trends: "messy polarity" wherein no single country provides the "structuring force" to the world order; the second is "a competitive world where everything is being weaponised"; And the third is "nationalism, revisionism plus identity politics."
He suggested that in order to escape this crisis and buck the above trends, the EU needs to become less Kantian, and more Hobbesian. There are several ways to read this statement, but I believe Borrell is articulating that the EU has assumed the universal appeal of its own values and its own aspirations for too long--and that these values and aspirations were bringing the world towards what Kant described as a "universal peace." Waking up to the cold new reality means jettisoning this approach and instead focusing on a politics of interest over values, recognizing that Europe is but one of many forces in the world. And it might also call for greater integration and centralization within the EU itself, depending on what element of Hobbes Borrell means to invoke.
"Let's try to understand the world the way it is and bring the voice of Europe," Borrell concluded.
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Environmental groups are taking on a Delaware sized oil and gas project in Wyoming. "Powder River Basin Resource Council and Western Watersheds Project filed the complaint in federal court in Washington, D.C. last month, claiming then-Interior Secretary David Bernhardt rigged the approval of the 5,000-well project 'to relieve the fossil fuel industry from federal environmental safeguards,'" reports WyoFile. "The 68-page filing names the Interior Department and U.S. Bureau of Land Management as defendants and seeks to reverse the approval."
Tunisia has one week of gasoline supply left, soon to be bolstered by a tanker currently unloading. "The petrol tanker now unloading at Bizerte will give Tunisia an extra few days of supply, taking it to 10-14 days in total, down from the usual 60 days of strategic reserves, said Salouan Smiri, a senior official in the oil section of the UGTT union. Tunisia is already facing shortages of some subsidised goods, with empty supermarket shelves causing protests last month, as it seeks an international bailout to finance debt repayments and state spending," reports Yahoo! Finance.
America exports light crude, and imports heavy. "Although large quantities of crude oil are produced in the United States, it still imports crude oil to meet domestic refining needs. Crude oils vary in qualities, including API gravity and sulfur content. Sweet crude oils have relatively low sulfur content, and sour crude oils have relatively high sulfur content," reports the Energy Information Administration. "The U.S. refining complex is advanced and capable of refining heavier, more sour crude oils, which generally cost less than lighter, sweeter grades of crude oil."
Crom's Blessing
A newsletter on fossil fuels, renewables, nuclear, and the grid. Read by investors, executives, engineers, policymakers, and more.
© 2023 Grid Brief.


Frederic Remington (1861-1909) was once one of many final American artists to supply his contemporaries a imaginative and prescient of the yankee previous West, that wild terrain with its substantial prairies, herds of bison and the final American Indians. A painter, yet certainly an illustrator renowned in his time, Remington skilfully captivated the public's recognition by means of offering a pragmatic view of this primitive lifestyle close to filing to invading civilisation. Authentically shooting its roughness, strength and likewise its colors, Remington quick turned the consultant of yank portray within the eyes of the area. notwithstanding he often focused on the attitudes of his characters and animals and never on his landscapes, his photographic sort, with an almost impressionist contact, renewed a style and lent an extra realism to his topics. Painter and sculptor, Remington additionally knew tips on how to sculpturally show the passion of those robust males and wild animals combating with the evolution of a brand new continent. The galloping horse, nonetheless famous this day as his signature topic, magnificently illustrates the facility of freedom emanating from those masterpieces.
Paintings Glass Nouveau was once initially released by way of Tuttle Publishing in print shape in 1967.
in the U.S., nice Britain, and different ecu nations through the overdue nineteenth and early twentieth centuries, whilst this effective artwork used to be at its peak. and not prior to has there been such an informative, helpful, and punctiliously illustrated ebook in this topic as this definitive paintings through Ray and Lee Grover.
not purely due to their infrequent good looks and authenticity, but additionally to teach consultant items, just like those who are nonetheless accessible. most crucial of all in deciding on a bit and selecting its worth, in response to the authors, are its colour, its form, and the feel of its floor, to which they consistently provide specific consciousness.
A booklet of soaking up curiosity and big erudition. . . . All Islamic archaeologists and students will thank Professor Grabar for a profound and unique research of a huge and complicated box, that can galvanize controversy yet needs to provoke through its mastery and beauty by means of its modesty.
This e-book explores interplay and pageant among portray and literature in France, from the past due 19th century to the early 20th, supplying new readings of works by way of key figures together with Paul Gauguin, Stéphane Mallarmé, Pablo Picasso and André Gide. Combining shut visible and literary research with a broader exam of severe discourse, the amount uncovers a mutual yet usually contentious alternate of rules.
With me cowboys are what gems and porcelains are to some others. Two very emaciated Texas ponies pattered down the street, bearing wild-looking individuals, whose hanging hair and drooping hats and generally bedraggled appearance would remind you at once of the Spanish-moss which hangs so quietly and helplessly to the limbs of the oaks out in the swamps. There was none of the bilious fierceness and rearing plunge which I had associated with my friends out West, but as a fox-terrier is to a yellow cur, so were these last.
Peter Newark's Western Americana, Bath, England. The Flight (A Sage-Brush Pioneer), 1895. 8 cm. The Hogg Brothers Collection, The Museum of Fine Arts, Houston, Texas. qxp The Fall of the Cowboy, 1895. 5 x 89 cm. Amon Carter Museum, Fort Worth, Texas. Antoine's Cabin, 1890. 8 cm. The Frederic Remington Art Museum, Ogdensburg, New York. 36 Page 36 In the heyday of the cowboy it was natural that his chief amusements should be those of the outdoor air and those more or less in line with his employment.
They all do it, but they never bring their troubles into court. They just shoot it out there in the bresh. The last time old Colonel Zuigg brought Zorn Zuidden in here and had him indicted for stealing cattle, said Zorn: 'Now see here, old man Zuigg, what do you want for to go and git me arrested fer? I have stole thousands of cattle and put your mark and brand on 'em, and jes because I have stole a couple of hundred from you, you go and have me indicted. " The argument was perfect. "From that I should imagine that the cow-people have no more idea of law than the gray apes," I commented.


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Concerns raised about Israel's agreements with third-party countries in Africa
A new Al Jazeera America report examines the Israeli government's 'voluntary departure' policy towards asylum seekers from Africa, many of whom have fled forced conscription in Eritrea or violence in Sudan.
The policy, in place since 2012, was set up to encourage African asylum seekers to leave Israel of their own volition. Asylum seekers who volunteer for return are given a one-way flight and $3,500. Many return to their own countries, despite the danger; some go to third-party countries instead.
RSC Research Associate Dr Reuven Ziegler told Al Jazeera that the programme does not violate the fundamental principle of non-refoulement, which stipulates that asylum seekers cannot be forcibly returned to danger. However, he does not know of any other government that pays asylum seekers to leave. (Israel does not deport asylum seekers to Eritrea, as this would constitute refoulement, and it does not deport asylum seekers to Sudan because the two countries have no diplomatic relations.)
He calls on Israel to make public its agreements with third-party African countries, where it sends Sudanese and Eritrean nationals who volunteer for the programme:
The state is not willing to say which are the destination states, is not willing to publish the agreement with these states, and is not willing at all to say what guarantees at all are provided by these states...These are all factors which I think raise serious concern.
According to recent research by the NGO Hotline for Refugees and Migrants, based in Tel Aviv, many asylum seekers volunteer to leave because they feel they have no other viable option. They are not allowed to work, cannot receive medical care or welfare (except in extreme circumstances) and must frequently renew their visas. Others are detained in the Holot Residency Center, an isolated facility located in the desert, where they have little freedom of movement and no right to work.
Ruvi Ziegler
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