text:
US 20070088528 A1 Abstract A system and method for monitoring a process in a process plant and detecting an abnormal condition includes collecting data representative of the operation of the process, performing a multivariate statistical analysis to represent the operation of the process in a known state based on a set of collected reference data, where the reference data includes a statistical measure of the operation of the process in the known state. The system and method may further include representing the operation of the process in an unknown state based on a set of monitored data, where the monitored data includes a statistical measure of the operation of the process in an unknown state, and using the output of the multivariate statistical analysis as an input, and comparing the process in the unknown state to the multivariate statistical representation of the operation of the process in the known state to determine the operational state of the process.
Claims(52) 1. A system for monitoring a process in a process plant, the system comprising:
a data collection tool adapted to collect data representative of an operation of the process; and a first analysis tool comprising a multivariate statistical analysis engine adapted to represent the operation of the process in a known state based on a set of collected reference data comprising a statistical measure of the operation of the process in the known state. 2. The system of
3. The system of
4. The system of
5. The system of
6. The system of
7. The system of
8. The system of
9. The system of
10. The system of
11. The system of
12. The system of
13. The system of
14. The system of
15. The system of
16. The system of
17. The system of
18. The system of
19. A method for monitoring a process in a process plant, the method comprising:
collecting data representative of an operation of the process; calculating a statistical measure on the collected data representative of the operation of the process in a known state; and performing a multivariate statistical analysis to represent the operation of the process in a known state based on a set of collected reference data comprising the statistical measure of the operation of the process in the known state. 20. The method of
21. The method of
22. The method of
23. The method of
24. The method of
25. The method of
26. The method of
27. The method of
28. The method of
comparing the representation of the process in an unknown state to the representation of the process in a known state; and detecting the presence of an abnormal process condition from the comparison. 29. The method of
30. The method of
31. The method of
32. The method of
33. The method of
34. The method of
35. The method of
36. The method of
37. A system for monitoring a process in a process plant, the system comprising;
a first analysis tool adapted to generate a multivariate statistical representation of the operation of the process in a known condition based on reference statistical data representative of the operation of the process in the known condition; and a second analysis tool adapted to represent the operation of the process in an unknown condition based on monitored statistical data representative of the process in the unknown condition within the multivariate statistical representation, and adapted to determine the unknown condition based on the observation of the monitored statistical data within the multivariate statistical representation as compared with the observation of the reference statistical data within the multivariate statistical representation. 38. The system of
39. The system of
40. The system of
41. The system of
42. The system of
x=vector of original process variable measurements
gi=likelihood that x belongs to abnormal condition class i
P=a principal component analysis loading matrix
Si=a covariance matrix of all observations belonging to class i
pi=a prior probability of an observation belonging to class i.
43. The system of
44. The system of
g i(x)=(x− wherein:
x=vector of original process variable measurements
gi=likelihood that x belongs to abnormal condition class i
P=a principal component analysis loading matrix
Si=a covariance matrix of all observations belonging to class i.
45. The system of
46. The system of
47. The system of
48. The system of
49. The system of
50. The system of
51. The system of
52. The system of
Description This patent claims priority from U.S. Provisional Application Ser. No. 60/726,962 which was filed on Oct. 14, 2005, the contents of which are expressly incorporated by reference herein in its entirety for all purposes. This patent relates generally to performing diagnostics and maintenance in a process plant and, more particularly, to providing predictive diagnostics capabilities within a process plant in a manner that reduces or prevents abnormal conditions within the process plant. Process control systems, like those used in chemical, petroleum or other processes, typically include one or more centralized or decentralized process controllers communicatively coupled to at least one host or operator workstation and to one or more process control and instrumentation devices such as, for example, field devices, via analog, digital or combined analog/digital buses. Field devices, which may be, for example, valves, valve positioners, switches, transmitters, and sensors (e.g., temperature, pressure, and flow rate sensors), are located within the process plant environment, and perform functions within the process such as opening or closing valves, measuring process parameters, increasing or decreasing fluid flow, etc. Smart field devices such as field devices conforming to the well-known FOUNDATION� Fieldbus (hereinafter �Fieldbus�) protocol or the HART� protocol may also perform control calculations, alarming functions, and other control functions commonly implemented within the process controller. The process controllers, which are typically located within the process plant environment, receive signals indicative of process measurements or process variables made by or associated with the field devices and/or other information pertaining to the field devices, and execute controller applications. The controller applications implement, for example, different control modules that make process control decisions, generate control signals based on the received information, and coordinate with the control modules or blocks in the field devices such as HART and Fieldbus field devices. The control modules in the process controllers send the control signals over the communication lines or signal paths to the field devices, to thereby control the operation of the process. Information from the field devices and the process controllers is typically made available to one or more other hardware devices such as, for example, operator workstations, maintenance workstations, personal computers, handheld devices, data historians, report generators, centralized databases, etc. to enable an operator or a maintenance person to perform desired functions with respect to the process such as, for example, changing settings of the process control routine, modifying the operation of the control modules within the process controllers or the smart field devices, viewing the current state of the process or of particular devices within the process plant, viewing alarms generated by field devices and process controllers, simulating the operation of the process for the purpose of training personnel or testing the process control software, diagnosing problems or hardware failures within the process plant, etc. While a typical process plant has many process control and instrumentation devices such as valves, transmitters, sensors, etc. connected to one or more process controllers, there are many other supporting devices that are also necessary for or related to process operation. These additional devices include, for example, power supply equipment, power generation and distribution equipment, rotating equipment such as turbines, motors, etc., which are located at numerous places in a typical plant. While this additional equipment does not necessarily create or use process variables and, in many instances, is not controlled or even coupled to a process controller for the purpose of affecting the process operation, this equipment is nevertheless important to, and ultimately necessary for proper operation of the process. As is known, problems frequently arise within a process plant environment, especially a process plant having a large number of field devices and supporting equipment. These problems may take the form of broken or malfunctioning devices, logic elements, such as software routines, being in improper modes, improperly tuned process control loops, one or more failures in communications between devices within the process plant, etc. These and other problems, while numerous in nature, generally result in the process operating in an abnormal state (i.e., the process plant being in an abnormal condition) which is usually associated with suboptimal performance of the process plant. Many diagnostic tools and applications have been developed to detect and determine the cause of problems within a process plant and to assist an operator or a maintenance person to diagnose and correct the problems, once the problems have occurred and been detected. For example, operator workstations, which are typically connected to the process controllers through communication connections such as a direct or wireless bus, Ethernet, modem, phone line, and the like, have processors and memories that are adapted to run software or firmware, such as the DeltaV� and Ovation control systems, sold by Emerson Process Management which includes numerous control module and control loop diagnostic tools. Likewise, maintenance workstations, which may be connected to the process control devices, such as field devices, via the same communication connections as the controller applications, or via different communication connections, such as object linking and embedding (OLE) for process control (OPC) connections, handheld connections, etc., typically include one or more applications designed to view maintenance alarms and alerts generated by field devices within the process plant, to test devices within the process plant and to perform maintenance activities on the field devices and other devices within the process plant. Similar diagnostic applications have been developed to diagnose problems within the supporting equipment within the process plant. Thus, for example, the Asset Management Solutions (AMS) Suite: Intelligent Device Manager application (at least partially disclosed in U.S. Pat. No. 5,960,214 entitled �Integrated Communication Network for use in a Field Device Management System�) sold by Emerson Process Management, enables communication with and stores data pertaining to field devices to ascertain and track the operating state of the field devices. In some instances, the AMS application may be used to communicate with a field device to change parameters within the field device, to cause the field device to run applications on itself such as, for example, self-calibration routines or self-diagnostic routines, to obtain information about the status or health of the field device, etc. This information may include, for example, status information (e.g., whether an alarm or other similar event has occurred), device configuration information (e.g., the manner in which the field device is currently or may be configured and the type of measuring units used by the field device), device parameters (e.g., the field device range values and other parameters), etc. Of course, a maintenance person may use this information to monitor, maintain, and/or diagnose problems with field devices. Similarly, many process plants include equipment monitoring and diagnostic applications such as, for example, RBMware provided by CSI Systems, or any other known applications used to monitor, diagnose, and optimize the operating state of various rotating equipment. Maintenance personnel usually use these applications to maintain and oversee the performance of rotating equipment in the plant, to determine problems with the rotating equipment, and to determine when and if the rotating equipment must be repaired or replaced. Similarly, many process plants include power control and diagnostic applications such as those provided by, for example, the Liebert and ASCO companies, to control and maintain the power generation and distribution equipment. It is also known to run control optimization applications such as, for example, real-time optimizers (RTO+), within a process plant to optimize the control activities of the process plant, Such optimization applications typically use complex algorithms and/or models of the process plant to predict how inputs may be changed to optimize operation of the process plant with respect to some desired optimization variable such as, for example, profit. These and other diagnostic and optimization applications are typically implemented on a system-wide basis in one or more of the operator or maintenance workstations, and may provide preconfigured displays to the operator or maintenance personnel regarding the operating state of the process plant, or the devices and equipment within the process plant. Typical displays include alarming displays that receive alarms generated by the process controllers or other devices within the process plant, control displays indicating the operating state of the process controllers and other devices within the process plant, maintenance displays indicating the operating state of the devices within the process plant, etc. Likewise, these and other diagnostic applications may enable an operator or a maintenance person to retune a control loop or to reset other control parameters, to run a test on one or more field devices to determine the current status of those field devices, to calibrate field devices or other equipment, or to perform other problem detection and correction activities on devices and equipment within the process plant. While these various applications and tools are very helpful in identifying and correcting problems within a process plant, these diagnostic applications are generally configured to be used only after a problem has already occurred within a process plant and, therefore, after an abnormal condition already exists within the plant. Unfortunately, an abnormal condition may exist for some time before it is detected, identified and corrected using these tools, resulting in the suboptimal performance of the process plant for the period of time during which the problem is detected, identified and corrected. In many cases, a control operator will first detect that some problem exists based on alarms, alerts or poor performance of the process plant. The operator will then notify the maintenance personnel of the potential problem. The maintenance personnel may or may not detect an actual problem and may need further prompting before actually running tests or other diagnostic applications, or performing other activities needed to identify the actual problem. Once the problem is identified, the maintenance personnel may need to order parts and schedule a maintenance procedure, all of which may result in a significant period of time between the occurrence of a problem and the correction of that problem, during which time the process plant runs in an abnormal condition generally associated with the sub-optimal operation of the plant. Additionally, many process plants can experience an abnormal condition that results in significant costs or damage within the plant in a relatively short amount of time. For example, some abnormal conditions can cause significant damage to equipment, the loss of raw materials, or significant unexpected downtime within the process plant if these abnormal conditions exist for even a short amount of time. Thus, merely detecting a problem within the plant after the problem has occurred, no matter how quickly the problem is corrected, may still result in significant loss or damage within the process plant. As a result, it is desirable to try to prevent abnormal conditions from arising in the first place, instead of simply trying to react to and correct problems within the process plant after an abnormal condition arises. Because of the potential impact of abnormal conditions on the plant environment, those in academia and industry have extensively studied the fields of Fault Detection and isolation (FDI) and abnormal condition prevention. Systems for detecting faults and/or abnormal conditions generally fell into one of two categories: model-driven methods and data-driven methods. Model-driven methods rely on the existence of some analytical or first-principals model of the system. A fault or abnormal condition is detected when the values of one or more process variables differ significantly from the values predicted by the model. However, model-driven methods typically are of limited use, because the accuracy of a model-driven FDI system or abnormal condition prevention system is dependent solely upon the accuracy of the model. For example, while a particular model may prove accurate for a new process plant, the accuracy of the model may decrease as the devices within the process age or wear or as changes occur in the process due to, for example, process optimization. Thus, after a period, a model that is accurate at the time of its creation may be of limited or no utility in detecting and isolating faults. Further, the creation of a new model to correct the condition may be costly and/or time-consuming and may suffer the same decrease in utility after a relatively short period. Data-driven techniques constitute the other subset of FDI and abnormal condition prevention methods. Data-driven techniques typically do not use an analytic model of the process, but instead apply information gathered about the process from the measured process variables available in a Distributed Control System (DCS). This data, which may constitute process variable data, includes both raw process variable data and statistical signature data (e.g., mean, standard deviation, maximum, minimum, etc.) or other meta-data. Some industrial processes use a number of data-driven techniques, such as principal component analysis (PCA), discriminant analysis, and partial least squares (PLS) for fault detection and isolation or abnormal condition prevention. Process plants employing data-driven FDI and abnormal condition prevention techniques traditionally use raw process variable data to �learn� about the process. However, raw process variable data does not always provide sufficient information to accurately predict and isolate abnormal conditions. However, it is also known to collect and generate statistical data that enables a user to predict the occurrence of certain abnormal conditions within a process plant before these abnormal conditions actually arise, with the purpose of taking steps to prevent the predicted abnormal condition before any significant loss within the process plant takes place. One method of collecting statistical data is disclosed in U.S. patent application Ser. No. 09/972,078, now U.S. Pat. No. 7,085,610, entitled �Root Cause Diagnostics� (which is a continuation-in-part of U.S. patent application Ser. No. 09/303,869, which in turn is a divisional of U.S. patent application Ser. No. 08/623,569, now U.S. Pat. No. 6,017,143). The entire disclosures of both of these applications are hereby expressly incorporated by reference herein for all purposes. Generally speaking, this technique places statistical data collection and processing blocks or statistical processing monitoring (SPM) blocks, in each of a number of devices, such as field devices, within a process plant. The statistical data collection and processing blocks collect, for example, raw process variable data and determine certain statistical signatures associated with the collected data, such as a mean, a median, a standard deviation, etc. These statistical signatures may then be sent to a user and analyzed to recognize patterns suggesting the future occurrence of a known abnormal condition. Once a particular suspected future abnormal condition is detected, steps may be taken to correct the underlying problem, thereby avoiding the abnormal condition in the first place. A system and method is provided for monitoring a process in a process plant. Specifically, the system and method collects data representative of an operation of the process and uses a multivariate statistical analysis to represent the operation of the process in one or more known states based on the collected data. The collected data includes one or more statistical measures of the operation of the process. Alternatively, a statistical calculation is performed on the collected data to provide one or more statistical measures. The system and method further represents the operation of the process in an unknown state based on monitored data, where the monitored data includes one or more statistical measures of the process in the unknown state. By comparing or representing the process in the unknown state with the multivariate statistical representation of the process in the one or more known states, the condition of the process may be determined. As such, the system may be used to detect or predict abnormal conditions within a process plant by analyzing the statistical measures from the process using a multivariate statistical analysis. In addition, the abnormal condition may be identified based on a likelihood that the monitored data is associated with a known abnormal condition. Using the statistical measures allows for more accurate detection and prediction of abnormal conditions in the process, which in turn may be used for more accurate alarms. Referring now to Still further, maintenance systems, such as computers executing the AMS application or any other device monitoring and communication applications may be connected to the process control systems 12 and 14 or to the individual devices therein to perform maintenance and monitoring activities. For example, a maintenance computer 18 may be connected to the controller 12B and/or to the devices 15 via any desired communication lines or networks (including wireless or handheld device networks) to communicate with and, in some instances, reconfigure or perform other maintenance activities on the devices 15. Similarly, maintenance applications 17 and 19 such as the AMS application may be installed in and executed by one or more of the user interfaces 14A associated with the distributed process control system 14 to perform maintenance and monitoring functions, including data collection related to the operating status of the devices 16. The process plant 10 also includes various rotating equipment 20, such) as turbines, motors, etc. which are connected to a maintenance computer 22 via some permanent or temporary communication link (such as a bus, a wireless communication system or hand held devices which are connected to the equipment 20 to take readings and are then removed). The maintenance computer 22 may store and execute known monitoring and diagnostic applications 23 provided by, for example, CSI (an Emerson Process Management Company) or other any other known applications used to diagnose, monitor and optimize the operating state of the rotating equipment 20. Maintenance personnel usually use the applications 23 to maintain and oversee the performance of rotating equipment 20 in the plant 10, to determine problems with the rotating equipment 20 and to determine when and if the rotating equipment 20 must be repaired or replaced. In some cases, outside consultants or service organizations may temporarily acquire or measure data pertaining to the equipment 20 and use this data to perform analyses for the equipment 20 to detect problems, poor performance or other issues effecting the equipment 20. In these cases, the computers running the analyses may not be connected to the rest of the system 10 via any communication line or may be connected only temporarily. Similarly, a power generation and distribution system 24 having power generating and distribution equipment 25 associated with the plant 10 is connected via, for example, a bus, to another computer 26 which runs and oversees the operation of the power generating and distribution equipment 25 within the plant 10. The computer 26 may execute known power control and diagnostics applications 27 such as those provided by, for example, Liebert and ASCO or other companies to control and maintain the power generation and distribution equipment 25. Again, in many cases, outside consultants or service organizations may use service applications that temporarily acquire or measure data pertaining to the equipment 25 and use this data to perform analyses for the equipment 25 to detect problems, poor performance or other issues affecting the equipment 25. In these cases, the computers (such as the computer 26) running the analyses may not be connected to the rest of the system 10 via any communication line or may be connected only temporarily. As illustrated in Although the process plant 10 is shown as including an FDI system 35, it should be understood that the FDI system 35 is not limited to detecting of existing, faults or other abnormal conditions, but may also predict the occurrence of an abnormal conditions examples of which as disclosed further below. As such, the FDI system 35 may be utilized to detect existing faults and other abnormal conditions within the process as part of fault detection and isolation, and to predict the occurrence of faults and other abnormal conditions within the process as part of abnormal condition prevention. For example, the fault detection module 44 may be utilized to detect existing and predicted abnormal conditions, as described herein. Further, although PCA is primarily disclosed as a multivariate statistical analysis technique that may be employed, it should be understood that PCA is provided only as an example, and PCA is explained in order to better understand the fault detection and abnormal condition prevention methodology employed. As such, other multivariate statistical analysis techniques may also be utilized, including, but not limited to partial least squares (PLS), principal component regression (PCR), discriminant analysis and canonical variate analysis (CVA). Different multivariate statistical analysis techniques may be utilized depending on the abnormal condition being detected. For example, while PCA may be utilized for both detecting and predicting abnormal conditions, PCA may be utilized to detect the occurrence of abnormal conditions whereas PLS and/or PCR may be utilized to predict the occurrence of abnormal conditions. As such, the FDI system 35 may include additional modules for different multivariate analysis techniques and/or the PCA module 42 may be replaced with a PLS module, a PCR module, a discriminant analysis module, a CVA module or any other multivariate statistical analysis module. Referring again to The fault detection module 44 analyzes monitored statistical signature (or raw process variable) data, using the results of the principal component analysis performed by the PCA module 42, to determine the existence or future existence of an abnormal process condition. As described in detail below, the fault detection module 44 may project the monitored statistical signature or raw process variable data into the score matrix, using the loading matrix previously determined by the PCA module 42. The fault detection module 44 may then generate one or more alerts or alarms for operators or maintenance personnel based on the results of the analysis, or otherwise alert process operators or maintenance personnel that an abnormal condition exists or is predicted. Likewise, the fault detection module 44 may store the results of the analysis, including faults detected, alerts or alarms generated, and data projected onto the score matrix (described below), in the database 43 or communicate the results to the viewing and interface application 40. The viewing and interface application 40 includes an interface for plant personnel such as configuration engineers, process control operators, maintenance personnel, plant managers, supervisors, etc. to view alerts and alarms generated by the fault detection module 44. The viewing application 40 may also include an interface that allows manipulation of various process control parameters, manipulation of the PCA module 42 and the fault detection module 44, and display of relevant data including statistical signature data, raw process variable data, auto-scaled data, data mapped on to score matrices or any other data useful to display for plant personnel. The viewing and interface application 40 may provide a graphical user interface (GUI) that is integrated with the system 30, or more particularly with the FDI system 35, to facilitate a user's interaction with the monitoring capabilities provided by the FDI system 35. However, before discussing the GUI in greater detail, it should be recognized that the GUI may include one or more software routines that are implemented using any suitable programming languages and techniques. Further, the software routines making up the GUI may be stored and processed within a single processing station or unit, such as, for example, a workstation, a controller, etc. within the plant 10 or, alternatively, the software routines of the GUI may be stored and executed in a distributed manner using a plurality of processing units that are communicatively coupled to each other within the FDI system 35. Preferably, but not necessarily, the GUI may be implemented using a familiar graphical windows-based structure and appearance, in which a plurality of interlinked graphical views or pages include one or more pull-down menus that enable a user to navigate through the pages in a desired manner to view and/or retrieve a particular type of information. The features and/or capabilities of the FDI system 35 may be represented, accessed, invoked, etc. through one or more corresponding pages, views or displays of the GUT. Furthermore, the various displays making up the GUI may be interlinked in a logical manner to facilitate a user's quick and intuitive navigation through the displays to retrieve a particular type of information or to access and/or invoke a particular capability of the FDI system 35. Those of ordinary skill in the art will appreciate that the FDI system 35 described herein may operate alone or in cooperation with other systems, including other fault detection and abnormal condition prevention systems. Likewise, the individual applications 38, 40, 42, and 44 described herein as part of the FDI system 35 may operate cooperatively with other applications (not shown) to detect faults, generate alerts and alarms, provide data to plant personnel, allow process or device configuration or any combination of the above. The portion 50 of the process plant 10 illustrated in In any event, one or more user interfaces or computer systems 14A and 30 (which may be any types of personal computers, workstations, etc. accessible by plant personnel such as configuration engineers, process control operators, maintenance personnel, plant managers, supervisors, etc.) are coupled to the process controllers 60 via a communication line or bus 76 which may be implemented using any desired hardwired or wireless communication structure, and using any desired or suitable communication protocol such as, for example, an Ethernet protocol. In addition, a database 78 may be connected to the communication bus 76 to operate as a data historian that collects and stores configuration information as well as on-line process variable data, parameter data, status data, and other data associated with the process controllers 60 and field devices 15 and 16 within the process plant 10. Thus, the database 78 may operate as a configuration database to store the current configuration, including process configuration modules, as well as control configuration information for the process control system 14B as downloaded to and stored within the process controllers 60 and the field devices 15 and 16. Likewise, the database 78 may store historical abnormal condition prevention data, including reference or monitored statistical signature data collected by the field devices 15 and 16 within the process plant 10 or reference or monitored statistical signature data determined from process variables collected by the field devices 15 and 16. While the process controllers 60, I/O devices 68 and 70, and field devices 15 and 16 are typically located down within and distributed throughout the sometimes harsh plant environment, the workstations 14A and 30, and the database 78 are usually located in control rooms, maintenance rooms or other less harsh environments easily accessible by operators, maintenance personnel, etc. Generally speaking, the process controllers 60 store and execute one or more controller applications that implement control strategies using a number of different, independently executed, control modules or blocks. The control modules may each be made up of what are commonly referred to as function blocks, wherein each function block may be a part or a subroutine of an overall control routine and operates in conjunction with other function blocks (via communications links) to implement process control loops within the process plant 10. As is well known, function blocks, which may be objects in an object-oriented programming protocol, typically perform one of an input function, such as that associated with a transmitter, a sensor or other process parameter measurement device, a control function, such as that associated with a control routine that performs PID, fuzzy logic, etc. control, or an output function, which controls the operation of some device, such as a valve, to perform some physical function within the process plant 10. Of course, hybrid and other types of complex function blocks exist, such as model predictive controllers (MPCs), optimizers, etc. It is to be understood that while the Fieldbus protocol and the DeltaV� system protocol use control modules and function blocks designed and implemented in an object-oriented programming protocol, the control modules may be designed using any desired control programming scheme including, for example, sequential function blocks, ladder logic, etc., and are not limited to being designed using function blocks or any other particular programming technique. As illustrated in Additionally, as shown in Generally, the blocks 80 and 82, or sub-elements of the blocks 80 and 82, collect data, such as raw process variable data, within the device in which they are located and perform statistical processing or analysis on the collected data, for example to aid in fault detection and isolation and in abnormal situation prevention. In addition, the block 80 includes one or more statistical process monitoring (SPM) blocks or units SPM1-SPM4. The statistical process monitoring (SPM) block provides functionality that performs statistical process monitoring on at least one process variable or other process parameter, and may be performed by any desired software, firmware or hardware within the device or even outside of a device for which data is collected. As an example and referring to Although examples of statistical signature data have been provided, it should be understood that the statistical signature data may include different types of statistical signature data for any statistical measure representative of the process. Additionally, while an example for generating statistical signature data has been provided, it should be understood that the SPM blocks may use a variety of techniques to generate the statistical signature data. For example, while the SPM blocks discussed herein may be known Foundation Fieldbus SPM blocks, the statistical process monitoring (SPM) block may be any type of block or element that collects data, such as raw process variable data, and performs some statistical processing on the data to determine a statistical measure, such as a mean, a standard deviation, etc. An SPM block may be implemented as software or firmware or other elements that perform the function of the SPM block, whether these elements are in the form of function blocks, or other types of blocks, programs, routines or elements and whether or not these elements conform to the Foundation. Fieldbus protocol, or some other protocol, such as PROFIBUS, WORLDFIP, Device-Net, AS-Interlace, HART, CAN, etc., protocols. It should also be understood that, because the SPMs are generally located in the devices where the raw process variable data is collected, the SPMs can acquire quantitatively and qualitatively more accurate process variable data. However, as described further below, SPM blocks may be placed outside of the device that collects or generates the process variable data, for example if the device does not have or does not support SPM functionality, although SPM blocks within the device may be capable of determining better statistical calculations with respect to the collected raw process variable data than a block located outside of the device. As another example, The ADBs, or the SPM blocks which may be provided therein, discussed with respect to The Standard Deviation, s, is a measure of how much the data varies from its mean. The Standard Deviation may be calculated as follows, where the denominator uses the term n−1 instead of n in order to provide an unbiased estimator of the standard deviation, given only a sample of the population:
While, Mean and Standard Deviation may be particularly useful parameters, other SPM parameters that may also be useful include Baseline Mean, Baseline Standard Deviation, Mean Change, Standard Deviation Change, and Status. Of course, the SPM blocks may be used to determine any other desired statistical measures or parameters and could provide other parameters associated with a particular block to a user or requesting application. Thus, SPM blocks are not limited to providing only the parameters discussed herein. Referring still to As mentioned above, it is possible to place SPM blocks outside of the devices that collect the raw process variable data or other data. For example, it is possible to place SPM blocks in host devices, devices other than field devices, or other field devices to perform statistical process monitoring outside of the device that collects or generates the raw data, such as the raw process variable data. Thus, for example, the configuration and data collection application 38 of As the number of statistical data collection blocks or SPMs increases in a process plant, it is helpful to have an automated mechanism that gathers the data from the SPM blocks in the different devices, to analyze the data and to provide detection results to an expert system for further data aggregation and decision-making. As described above, data collected by the field devices 15 and 16 within the process plant 10 may be aggregated in the database 78, the statistical process monitoring database 43, or any other memory suitable for storing raw process variable data. In addition to raw process variable data, the data may include statistical signature data processed by the SPM blocks in field devices 15 and 16, or may be statistical signature data determined by the PCA module 42 from the raw process variables collected by the field devices 15 and 16. The filters 84 remove the higher frequency noise from the signal to the controllers 12B and 14B. In many applications, however, the higher frequency noise contains useful information about the operation of the measured process. For example, the high-frequency component of a pressure signal in one type of industrial furnace can be indicative of flame instability. The filters 84 would remove this useful diagnostic information from the signal in a traditional instrumentation system and prohibit this type of diagnostics. Many field devices 15 or 16 now use digital protocols to communicate with controllers 12B and 14B, allowing the devices to communicate additional information that may be useful in an FDI system. For example, the HART� protocol enables smart devices to engage in two-way digital communications on traditional 4-20 mA loops already in use, without disturbing the integrity of the 4-20 mA signal. HART� accomplishes this by superimposing digital communication signals at a low level on top of the 4-20 mA signal using Bell 202 Frequency Shift Keying (FSK). By contrast, the Fieldbus protocol is an all-digital, serial, two-way communications system that serves as a Local Area Network (LAN) for plant instrumentation and control devices, replacing entirely the individual pairs of wires of the 4-20 mA system. Other digital protocols include, for example, PROFIBUS�, WORLDFIP�, Device-Net�, AS-Interface and CAN protocols. Digital protocols make it possible for a field device 15 or 16 to communicate more than its primary process variable (e.g., pressure, temperature, etc.) to the controller 12B or 14B, and ultimately to the computer system 30 implementing the FDI system 35. While the filters 84 remove higher frequency information from the analog signal, one or more SPM blocks in the ADB 80 may still use the higher frequency information in that signal to compute a number of statistical measures for a process variable, such as a mean, a median, a standard deviation, etc. Having calculated statistical signatures such as a mean or a standard deviation from the raw analog signal, a field device 15 or 16 using a digital protocol can communicate both the raw process variable data and the statistical signature data to the controller 12B or 14B. The controllers 12B and 14B are communicatively coupled to the FDI system 35 by any suitable method such as Ethernet, Modbus, HTML, XML, proprietary techniques and/or protocols etc., as described above. This coupling may be direct or through an intermediary system such as one of the computers 22 or 26. Those skilled in the art may conceive of many configurations in which devices may communicate data to the FDI system 35 for use by the PCA module 42. As described above, the PCA module 42 analyzes process variable data associated with known normal and abnormal process conditions to determine principal components that represent the largest amount of total variance in the process variable data. The PCA technique transforms a set of data from a high dimensional space to a lower dimensional space, capturing only the most important variations. In particular, for a given set of data, m is the number of variables and n is the number observations (e.g., data points) of each variable. A matrix X is an n�m matrix containing all of the observations for all of the input variables. In a typical process, some process variables have magnitudes significantly larger than others. In order to ensure that each process variable has an equal effect on the model, it may be desirable to autoscale the X data (e.g., sealing the data against itself) by subtracting the mean for each process variable from each data point and dividing by the standard deviation for the process variable. For the autoscaled matrix, the sample covariance matrix is calculated by:
An Eigenvalue-Eigenvector decomposition is performed on the sample covariance matrix:
Here, D is a diagonal matrix containing the m Eigenvalues, and the columns of V are Eigenvectors corresponding to each of the Eigenvalues. After performance of the Eigenvalue-Eigenvector decomposition), the Eigenvalues (and corresponding Eigenvectors) are sorted from largest to smallest. The largest Eigenvalue, and its corresponding Eigenvector, indicates the direction in a new linear space that corresponds to the largest variance in the original data set. The second largest Eigenvalue, and its Eigenvector, correspond to a direction, orthogonal to the first, with the second largest amount of variance. In a similar manner, all fit Eigenvalues, and their corresponding Eigenvectors, create an orthogonal transformation of the original linear space. Typically, a given analysis retains the number of principal components, p, that represent the largest amount of variance, while discarding the m−p (i.e., m minus p) principal components representing the least variance. For raw process variable data, the p largest Eigenvalues correspond to the actual underlying variance in the process, while the m−p smallest Eigenvalues correspond to background noise. One of several methods may be used to determine how many principal components to retain. These methods include, by way of example and not limitation, cross-validation, parallel analysis, the percent variance test, the chi-square test, the scree test, and the Minimum Average Partial, Briefly, parallel analysis compares the Eigenvalues found in the Eigenvalue-Eigenvector decomposition against those that would have been obtained from a similar data set with independent measurements and observations. When a represents the number of the largest Eigenvalues being retained, the loading matrix Pε m�a is created by taking the first a columns from the Eigenvector matrix V. The projection of the original observations onto the new subspace defined by the loading matrix is called the score matrix, and denoted by T=XP.The base PCA decomposition described above provides a method to reduce a data set of many correlated measurements into a few significant components. However, the detection and isolation of an abnormal condition may require additional logic, based on discriminant analysis. When PCA is utilized to discriminate between multiple fault cases, either a single PCA model may be developed for all fault classes or process conditions combined (PCA1) or a separate PCA model may be developed for each different fault class or process condition (PCAm). The example below uses the PCA1 approach, though those of ordinary skill in the art would readily appreciate that the PCAm approach could also be used. Using the PCA1 approach, the data for all classes are stacked into a single matrix X, wherein the loading matrix is associated with a combination of conditions. Within a scheme using a single PCA model, any single observation x can be assigned to a condition according to the maximum score discriminant:
In the case of fault detection in an industrial process, there is typically no a priori probability known for each of the fault classes. In this case, pi=0 may be assumed for all i, and the score discriminant reduces to:
While the following description describes fault detection using PCA primarily with respect to statistical signature data, it should be understood that PCA may also be used with raw process variable data rather than statistical signature data, as noted throughout the description. However, it is possible that the raw process variable data may contain data point outliers or otherwise erroneous data points within the set, which may indicate a false condition in the process. As such, it may be preferable to utilize statistical signature data to account for, or minimize the effects of, data point outliers or other erroneous data contained within a set of raw process variable data, by generating statistical measures of the process variables from the raw process variable data. Statistical signature data may also provide additional information (e.g. variance) about the process which may not be readily apparent from raw process variable data alone. Further, although the following description describes fault detection using PCA to detect the existence of abnormal conditions, it should be understood that PCA or other multivariate statistical analysis techniques may be used for abnormal condition prevention to predict the future occurrence of abnormal conditions. In order to accomplish fault detection using PCA, it may be desirable to collect and analyze reference raw process variable data correlated to both normal and abnormal conditions in a process, for comparison with monitored process variable data. Statistical signature data may be developed from the collected raw process variable data, for example using the SPM blocks described above, to provide statistical signature data for known normal conditions in a process and for known abnormal conditions in the process. Using the reference statistical signature data (or the reference raw process variable data) associated with normal operation of a process, the PCA module 42 can determine the principal components for the process under normal conditions. Further, the PCA module 42 can determine from the statistical signature data (or from the reference raw process variable data) the principal components for the process under any abnormal condition for which associated reference statistical signature data (or reference raw process variable data) exists. As such, using the PCA1 method, principal components for a combination of known normal and/or known abnormal situations may be developed in which the same PCA model is associated with multiple conditions (e.g., all fault cases). Alternatively, using the PCAm approach, principal components for known normal and known abnormal situations may be developed for a variety of process variables. With the SPM block having generated reference statistical signature data from reference raw process variable data collected by the configuration and data collection application 38, and the PCA module 42 having determined a loading matrix associated with the reference statistical signature data (or reference raw process variable data), the fault detection module 44 may analyze monitored statistical signature data (or monitored raw process variable data). The fault detection module 44, projecting the monitored statistical signature data (or the monitored raw process variable data) onto the subspace defined by the loading matrix as described above, may categorize the monitored statistical signature data (or the monitored raw process variable data) as indicating of the presence or predicted future occurrence of either a normal or an abnormal process condition. If the monitored process variable data indicates a current or predicted abnormal condition, the fault detection module 44 may indicate which fault case is present or predicted. While a trending analysis may be provided to predict the future occurrence of a normal or abnormal process condition, it should be understood that various other prediction techniques may be provided. Reactant A flows into the system through a feed valve 108. A flow rate transmitter 104 measures the flow rate of Reactant A through the feed valve 108. A controller block 106, receives a process variable signal from the flow rate transmitter 104, and regulates the flow of Reactant A to a constant set point by sending a control signal to the feed valve 108 controlling the flow of Reactant A. Reactant B likewise flows into the system through a feed valve 118. A flow rate transmitter 110 measures the flow rate of Reactant B through the feed valve 118. Both Reactant A and Reactant B flow through a static mixer 112, where they combine to form Product C. A conductivity transmitter 114 measures the concentration of Product C as it flows out of the static mixer 112. A controller block 116, receiving a process variable signal from the conductivity transmitter 114, regulates the flow of Reactant B into the static mixer 112 (and thereby the concentration of Product C) by sending a control signal to the feed valve 118 controlling the flow of Reactant B. The sodium acetate (Product C) flows from the static mixer 112 to the reactor 102. An agitator motor 120 drives the agitator 122 within the reactor 102, stirring the contents 124 of the reactor 102 and causing the further reaction, which chances the sodium acetate to ethyl alcohol (Product D). As mentioned above, optimal process performance requires maintenance of both the level and the temperature of the contents 124. A level transmitter 134 measures the level of the contents 124 of the reactor 102. A controller block 136, receives a process variable signal from the level transmitter 134, and regulates the flow of ethyl alcohol out of the reactor 102 by sending a control signal to the discharge valve 138 controlling the discharge of ethyl alcohol and maintaining the level of the contents 124 of the reactor 102 at the desired set point. Likewise, a temperature transmitter 144 measures the temperature of the reactor 102. A pump 142 pulls ethyl alcohol out of the reactor 102. Some portion of the ethyl alcohol being pumped out of the reactor 102 by the pump 142 is discharged to the next stage of the system (not shown), while the remainder of the ethyl alcohol being pumped out of the reactor 102 by the pump 142 flows through a heat exchanger 140 where it is cooled and recirculated back into the reactor 102. The cooling effected by the heat exchanger 140 maintains the reaction within the reactor 102 at the desired temperature. A temperature transmitter 154 measures the temperature of ethyl alcohol flowing out of the heat exchanger 140. The process 100 uses a cascaded control algorithm to regulate the flow of the coolant to maintain the appropriate temperature in the reactor 102. A master controller block 155, receiving a process variable signal from the temperature transmitter 144, sends a control signal to a slave controller block 156 which also receives information from the temperature transmitter 154. The slave control block 156 adjusts the flow rate of the coolant through the heat exchanger 140 by sending a control signal to the coolant valve 158. It is noted that the field devices do not need to communicate directly from one device to another. For example, the controller block 106 and/or feed valve 108 need not receive a signal directly from the flow rate transmitter 104. Instead, field devices may also receive a signal through some intermediary entity, such as a controller or computer system. The example process 100 illustrated in In the example process 100 illustrated in Alternatively, rather than inducing abnormal situations in the process, previously collected monitored statistical signature data (or monitored raw process variable data) may be utilized. For example, data stored in the statistical process monitoring database 43 (see For the list of faults induced (or otherwise analyzed) in the above table, there exist eight classes of observations. One class of observations is the normal operation of the process. Upset in Reactant A, heat exchanger fouling, and feed valve degradation each constitute another class of observations. Lastly, for each of the measurement bias errors, the transmitter reading could be higher than the actual value or lower than the actual value. Therefore, each could be in one of two directions (high or low) and constitute two classes of observations. As an example of utilizing PCA on raw process variable data in a process, such as the process 100 illustrated in Each time the process 100 resumed its normal state, several minutes passed before all the process variables stabilized and returned to their normal values. Thus, some post-processing was used with the process variable data to remove the data from the transitional period between fault and normal operating conditions. The post-processing removed the first half (30 minutes) of the data for each data set collected during the normal state. While the process 100 typically returned to its normal operating state in significantly less time, the post-processing ensured that the normal operating condition class would not contain any data from the transitional period. Likewise, Referring now to Using the score discriminant function (eq. 6), a fault classification decision can be made for each of the raw process variable data. Table 3 shows a summary of how the raw process variable data of Table 3 shows that a fault classification system analyzing the raw process variable data of As indicated above, it is possible that the raw process variable data may contain data point outliers or otherwise erroneous data points within the set, which may indicate a false condition in the process, such as a missed alarm or a false alarm. In an FDI system, missed alarms may be considered more acceptable than false alarms, especially when the system is new. For example, missed alarms leave plant personnel no worse off than before the installation of the FDI system. However, false alarms cause plant personnel to spend time and resources chasing down problems that do not exist. After a few such alarms, plant personnel are likely to simply ignore the FDI system, or turn it off completely. Typically, missed alarms are not too much of a problem where the rate of occurrence is less than 10%. False alarm rates, however, particularly those as high as in the heat exchanger fouling and temperature error examples above, are generally too high for most fault detection systems. As an alternative to using raw process variable data, one could analyze the same data set processing the PCA algorithm, but using statistical signature data based on the raw process variable data as reference data for the PCA calculations instead of the raw process variable data itself. Referring back to As an example, the raw process variable data collected in the process 100 above, part of which is shown in As an example of utilizing PCA on statistical signature data in a process instead of raw process variable data, analysis of the process 100 illustrated in Table 4, below, shows a summary of the results when the score discriminant classification method (eq. 6) is applied to each of the samples:
The relative improvement achieved by using statistical signature data as reference data for PCA instead of raw process variable data can be understood by referring again to While the FDI system 35 and other process elements have been described as preferably being implemented in software, they may be implemented in hardware, firmware, etc., and may be implemented by any other processor associated with the process control system 10. Thus, the elements described herein may be implemented in a standard multi-purpose CPU or on specifically designed hardware or firmware such as an application-specific integrated circuit (ASIC) or other hard-wired device as desired. When implemented in software, the software routine may be stored in any computer readable memory such as on a magnetic disk, a laser disk, or other storage medium, in a RAM or ROM of a computer or processor, in any database, etc. Likewise, this software may be delivered to a user or a process plant via any known or desired delivery method including, for example, on a computer readable disk or other transportable computer storage mechanism or over a communication channel such as a telephone line, the internet, wireless communication, etc. (which are viewed as being the same as or interchangeable with providing such software via a transportable storage medium). Thus, while the present invention has been described with reference to specific examples, which are intended to be illustrative only and not to be limiting of the invention, it will be apparent to those of ordinary skill in the art that changes, additions or deletions may be made to the disclosed embodiments without departing from the spirit and scope of the invention. Referenced by
Legal Events
Rotate |


text:
My name is Brianna. I'm 22 and from the central Jersey area. I drive a 2002 Ford Taurus and a 1994 Corvette C4. I'm a New England Patriots fan despite being in NJ. I like shopping, movies, football, exotic cars, writing, reading, hanging out with friends, British TV shows (The Inbetweeners ), and all things European. I'm especially in love with Germany I can understand a decent amount of German but not speak it too well. I also loooove the Russian language. I'm single. I love giving advice to people. I love jokes, especially offensive ones. I've been told I'm pretty funny. I'm also really sensitive, nice, and selfish at times. I'm really good with money, and people call me cheap because I don't waste money. But that's why I drive a corvette and they don't. Team iPhone. Tattooed. Likes rollerblading and iceskating. Also loves pizza... especially Hawaiian. Verified basic b***h.
I have Instagram: br0wneyed_babe & I usually always follow back. Especially if you say you're from Gaia
I have a Tumblr here.
♥ The very top and below pictures are not mine. They are taken from Tumblr. ♥
Viewing 12 of 20 friends
Asexual. 22. Germaniac. College student.

subset: commoncrawl


text:
Sun Metro to debut new for of transportation in El Paso
POSTED: Friday, June 6, 2014 - 5:36pm
UPDATED: Monday, June 9, 2014 - 7:59am
A new form of transportation will soon hit the streets of El Paso.
Today sun metro performed practice runs of the Brio Service. It's similar to light rail transit-- meaning its faster than traditional bus service. The Mesa corridor should open this summer.
Three other corridors on Alameda, Dyer and Montana are in the works.
Sun Metro says the practices runs are helping them finalize run times and identify possible detour routes if needed.
El Pasoans won't be able to board, but can get an up close look at the Brio tomorrow at 9 am at the Westside Regional Command Center.


text:
How to Isolate an image and create a clipping path for text flow
Installation • Usage • PDF issues • Imposition • Other |
Sometimes you have an image that you want text to flow around but you don't want the background of the image to show. If that's the case you can isolate the image and create a clipping path so Scribus can flow the text around that.
NOTE: A clipping path is one of the things Scribus can use to flow text around an image. Other things, such as a contour line, are available but won't be explained here.
This tutorial is a little unusual for the Scribus Wiki in that it is in two parts. The first part is in GIMP, the second part is in Scribus.
It's been written this way in order to show how you can use both applications to create an effect that is used in many professional publications.
IMPORTANT: This tutorial isn't really for people who haven't used either GIMP or Scribus before. Total beginners might get a bit lost as I don't explain everything down to the fine detail but most people who have used both applications should be able to follow it quite easily.
Part 1 - The GIMP Work
First you'll need an image to work on.
You can use any image you want - within reason - but if you want to follow along you'll need to download the image (figure 1) I've used from here: http://pixabay.com/en/auto-audi-black-vehicles-tuning-383897/ (I'd recommend downloading the 1280x850 version as it will look nice but the choice is up to you.)
The image you choose should, ideally, have one main "focus" and the background should be relatively "bland". The more bland the background the easier it will be to isolate the image. (Also, hair and fur are a nightmare to isolate properly without putting in a lot of time.)
Step 1A - Selection
- Load the image into GIMP.
You will be doing quite a lot of precision work here so it's best if you zoom in, 200% is good.
- Select the "Free Select Tool" from the Toolbox. (It's the one that looks like a cowboy's noose.)
- Make sure that "Antialiasing" is ticked.
- Make sure that "Feather edges" is also ticked and the "Radius" is set to 2.
Setting the Antialiasing and feathering like this works well for most images but you can experiment with using different settings.
On this image you want to isolate the car and to do that you need to make a selection that encompasses that car without including the background. Essentially what you do is draw a line around what you want to isolate.
- Click where you want to start and then keep clicking round the shape you want to isolate from the image (figure 2).
At this point you don't need to be extremely accurate as you can go back and alter any minor mistakes - pressing backspace undoes the last point you clicked, but the more time you take getting it right the better the outcome will be. Use small distances between clicks to go round curves but use long distances for straight edges (such as, in this instance, the underside of the car and the bottom of the tyres).
Your goal is to draw a line with the select tool completely around the object you want to isolate while having as little of the background inside the selection (figure 3).
If in doubt as to where to draw the selection line draw it very slightly inside the bit of the image you're trying to isolate instead of outside.
For the purposes of this tutorial you can make the selection as crude as you want but you'll see the effect better if you take the time to trace the object properly.
Step 1B - Isolation
- Once you've gone all round your image and you're happy with the selection line, choose menu "Select -> Invert".
This inverts the selection so you have now got the background selected.
- Select the "Bucket Fill Tool" from the Toolbox. (It looks like a bucket, not surprisingly.)
- Go to the colour samples - figure 4 - just below the tools and make sure that white is the foreground colour. (We're using white here because the page we'll be putting the image onto will be white.)
- Make sure "FG color fill" is set (underneath the colour samples).
- Make sure "Fill whole selection" is also set.
- Move the cursor over to the background of your image and click.
If you're not happy with what has been erased, use the Undo function and alter the selection using any of the selection tools. (There are plenty of really good tutorials on the web about using GIMP's selection tools so I won't give any more information here but see the Epilogue to this tutorial for a little tip.)
- Choose menu "Select - Invert" to get the selection back to the image rather than the background.
- Choose menu "Select -> Grow…".
- Enter a size that you want to enlarge the selection by. (I've used 32px as I don't want the text to touch the image but you can use whatever you want.) Use 32px if you're following along.
You should now see that the selection has grown and there's a "gap" around the image (figure 6).
NOTE: If you didn't fill the background with white earlier your selection would now include some of the background, and that's not what you want in this case.
Step 1C - Adjustments
Before continuing you need to keep in mind that Scribus will try its best to fit the text around the image in the most efficient way it can. This means that it will try and put text wherever it can including "concave" areas, such as - in this instance - the area under the car.
To remove these areas you'll need to add more to your selection.
- Select the "Free Select Tool" from the toolbox again.
- In the "Free Select" options under the tools select the "Add to the current selection" mode.
- Now draw a new selection that goes from the bottom of the rear tyre to the bottom of the front tyre, then inside the original selection under the front wheel arch, then under the rear wheel arch, then back to your start point.
- Next use the same technique to remove the gap from under the front of the car (figure 7).
You now need to make a clipping path for the image so text will flow around it.
NOTE: Once you've tried this tutorial, try it again but without making these adjustments so you can see what happens to the text under the car.
NOTE: In most cases you would also shrink the overall size of the image to remove all of the un-needed white area outside of the selection but we won't bother with that here.
Step 1D - Clipping Path
- Choose menu "Select -> To Path".
GIMP will now create the clipping path according to the selection. This may take a little while on slow computers with a large image. A status bar at the bottom of the GIMP main window will show its progress.
- Once done, choose menu "File -> Export As…".
- Set the file type to TIFF - give the file a suitable name if you want to - and press the "Export" button.
- Set whatever compression options you want, or accept the default, and press the "Export" button again.
You've now got an image with a clipping path.
IMPORTANT: You need to save as TIFF as JPEG doesn't allow clipping paths.
Part 2 - The Scribus Work
Now you will put the image into a document and put some text around it.
Step 2A - Base Image
- Go to Scribus and either open a new document or open a document you want to put your image into.
- Create an image frame. (For the purposes of this tutorial, make it pretty big so you can get the whole image in.)
- Right-click the image frame and choose "Get Image…".
- Select the TIFF image and press the "OK" button.
You may need to resize your image to get it how you want it inside the frame. Do so before proceeding.
Step 2B - The Text
- Create a text frame over the image frame. Where you put it is up to you depending on the effect you want to see. I've just made a text frame a bit larger than the image frame so you can see the effect.
- Right-click the text frame and choose "Sample text".
You can load your own text or type it using the editor as normal if you want but I'm suggesting sample text here for demonstration purposes.
- Press the "OK" button to create the sample text.
- Go to "Properties / Text" and in the "Columns and Text Distances" area make the number of columns 2 and make the gap between them 20pt.
NOTE: You don't always need to do this, depending on your needs, but if you don't do this - for the purposes of this tutorial - the text will be difficult to read as sentences will run from one side of the image to the other. Once you're finished with the tutorial try setting the number of columns back to 1 and see for yourself.
The text should be written all over the image (figure 8), but that's fine for now.- Right-click the text frame and choose "Level -> Lower to Bottom".
The image should be above the text but there's a load of white space. No problem.
Step 2C - Using the Clipping Path
You now need to tell Scribus to use the clipping path you created earlier.
- Right-click the image and choose "Extended Image Properties".
- Select "Selection" - you can see the shape of the path - and press the "OK" button.
There is now a "boundary" - the gap you created by "growing" the selection earlier - around the image but the text isn't flowing around it.
- In "Properties / Shape" select "Use Image Clip Path".
Ta Da!
The text now flows nicely around the image. Fantastic.
There are lots of different ways that you can create a selection in GIMP - before you create the clipping path - and they all have their disadvantages and advantages depending on the effect you're trying to achieve.
For instance, for images where the background is mostly one colour, why not try the "Fuzzy Select Tool" on the background to see if you can create the "inverted" selection - as you'd get at the start of Step 1B - with just one click?
Have a play around and see what you can achieve.


text:
Similar products
Customer Reviews
Customer Reviews
- Wonderful bow Review by Alya
Value Quality Price I used youth bows up until the point I could 'graduate' to my mothers recurve. While I used hers I spent ages looking for my own - and I instantly fell in love with this one on sight. The feel is perfect, it's a gorgeous bow, and I've had it for almost exactly a year now, and still love it as much as the day it arrived :)
(Posted on 1/2/14)
- Amazing bow. shots like a pro Review by MR.RIVERA
Price Value Quality i just got my bow in today and all i can say is wow. The physical appearance of this bow will take your breath away and it will do the same with the performance and sturdiness of the bow. Samick did a outstanding job making this one piece bow.
(Posted on 10/19/13)
- best product ever Review by sammy
Price Value Quality BUYY THIS NOW!!!!!
(Posted on 2/25/13)
- great bow Review by Timmy N Chapman Jr.
Price Value Quality I love this bow its my second bow. But I was surprise d at how nice it really is for the money and once its set up and tuned right they shot great
(Posted on 2/21/13)
- Great value...shoots like a much more expensive bow Review by Bowgod
Price Value Quality This bow is great for the beginner through intermediate archer, but an advanced archer opting to take off the training wheels will still feel comfortable with this bow. Cosmetically it fits the eye, does not have the outrageously oversized grip area that is frequent to many other bows of this length and, when in the hands of a decent archer, drills targets.
(Posted on 10/4/11)
- Good bow for the money Review by Bristol Archer
Price Value Quality i bought this just to play with in the backyard. Now it's the first bow I reach for everyday. Great for 3d shoots. Fun bow. Great value.
(Posted on 9/21/11)


text:
Stay indoors with these. Dust magnet otherwise.
@_DeLi_ guess you've never seen kids wear uggs. dumb ass. they must not have those in the hood.
@TheOddestFuture I'm not surprised with a name like "oddest"
I lack the vocabulary to think of a word that goes beyond "terrible." I wouldn't buy these even if they were at walmart AND their price drop!!!


text:
CNS Immune Responses Following Experimental Stroke
- Dannielle Zierath,
- Matthew Thullbery,
- Jessica Hadwin,
- J. Michael Gee,
- Anna Savos,
- Angela Kalil,
- Kyra J. Becker
- … show all 7 hide
Rent the article at a discount
Rent now* Final gross prices may vary according to local VAT.
Get AccessAbstract
Background and purpose
Animals subjected to an inflammatory insult with lipopolysaccharide (LPS) at the time of stroke are predisposed to develop a detrimental autoimmune response to myelin basic protein (MBP). In this study, we sought to determine whether other inflammatory stimuli could similarly invoke central nervous system (CNS) autoimmunity and whether these detrimental autoimmune responses occurred to antigens other than MBP.
Male Lewis rats underwent 3 h middle cerebral artery occlusion (MCAO) and received intraperitoneal injections of LPS, staphylococcal enterotoxin B (SEB), lipoteichoic acid (LTA) or saline at the time of reperfusion. Behavioral tests were performed at set time intervals after MCAO and animals were sacrificed at 1 month to analyze the immune response to MBP, neuron specific enolase (NSE) and proteolipid protein (PLP).
Lymphocytes from SEB treated animals were highly reactive to all tested CNS antigens, but treatment with LPS was most likely to lead to a Th1(+) response. A Th1(+) response to MBP, NSE or PLP in spleen was associated with worse outcome, although the response to NSE was most predictive of poor outcome. Animals with a cell mediated autoimmune response to either MBP or NSE in spleen had a concomitant humoral response to these antigens.
These data show that LPS, but not other inflammatory stimuli, increase the likelihood of developing a detrimental autoimmune response to an array of brain antigens.
- Netea MG, van der Graaf C, Van der Meer JW, Kullberg BJ. Toll-like receptors and the host defense against microbial pathogens: bringing specificity to the innate-immune system. J Leukoc Biol. 2004;75:749–55. CrossRef
- Janeway CA Jr, Medzhitov R. Innate immune recognition. Annu Rev Immunol. 2002;20:197–216. CrossRef
- Becker KJ, Kindrick DL, Lester MP, Shea C, Ye ZC. Sensitization to brain antigens after stroke is augmented by lipopolysaccharide. J Cereb Blood Flow Metab. 2005;25:1634–44. CrossRef
- Kilic U, Kilic E, Matter CM, Bassetti CL, Hermann DM. TLR-4 deficiency protects against focal cerebral ischemia and axotomy-induced neurodegeneration. Neurobiol Dis. 2008;31:33–40. CrossRef
- Caso JR, Pradillo JM, Hurtado O, Leza JC, Moro MA, Lizasoain I. Toll-like receptor 4 is involved in subacute stress-induced neuroinflammation and in the worsening of experimental stroke. Stroke. 2008;39:1314–20. CrossRef
- Cao CX, Yang QW, Lv FL, Cui J, Fu HB, Wang JZ. Reduced cerebral ischemia-reperfusion injury in Toll-like receptor 4 deficient mice. Biochem Biophys Res Commun. 2007;353:509–14. CrossRef
- Aslanyan S, Weir CJ, Diener HC, Kaste M, Lees KR. Pneumonia and urinary tract infection after acute ischaemic stroke: a tertiary analysis of the GAIN International trial. Eur J Neurol. 2004;11:49–53. CrossRef
- Harms H, Prass K, Meisel C, et al. Preventive antibacterial therapy in acute ischemic stroke: a randomized controlled trial. PLoS ONE. 2008;3:e2158. CrossRef
- Longa EZ, Weinstein PR, Carlson S, Cummins R. Reversible middle cerebral artery occlusion without craniectomy in rats. Stroke. 1989;20:84–91.
- Huang W, Koller LD. Superantigen activation and kinetics of cytokines in the Long-Evans rat. Immunology. 1998;95:331–8. CrossRef
- Chatterjee PK, Zacharowski K, Cuzzocrea S, et al. Lipoteichoic acid from Staphylococcus aureus reduces renal ischemia/reperfusion injury. Kidney Int. 2002;62:1249–63. CrossRef
- Bederson JB, Pitts LH, Tsuji M, Nishimura MC, Davis RL, Bartkowski H. Rat middle cerebral artery occlusion: evaluation of the model and development of a neurologic examination. Stroke. 1986;17:472–6.
- Hernandez TD, Schallert T. Seizures and recovery from experimental brain damage. Exp Neurol. 1988;102:318–24. CrossRef
- Becker K, Kindrick D, McCarron R, Hallenbeck J, Winn R. Adoptive transfer of myelin basic protein-tolerized splenocytes to naive animals reduces infarct size: a role for lymphocytes in ischemic brain injury? Stroke. 2003;34:1809–15. CrossRef
- Becker KJ. Sensitization and tolerization to brain antigens in stroke. Neuroscience. 2009;158:1090–7. CrossRef
- Pasare C, Medzhitov R. Toll-like receptors and acquired immunity. Semin Immunol. 2004;16:23–6. CrossRef
- Toubi E, Shoenfeld Y. Toll-like receptors and their role in the development of autoimmune diseases. Autoimmunity. 2004;37:183–8. CrossRef
- Huang YH, Haegerstrand A, Frostegard J. Effects of in vitro hyperthermia on proliferative responses and lymphocyte activity. Clin Exp Immunol. 1996;103:61–6. CrossRef
- Croft M, Dubey C. Accessory molecule and costimulation requirements for CD4 T cell response. Crit Rev Immunol. 1997;17:89–118.
- Hickey WF, Kimura H. Perivascular microglial cells of the CNS are bone marrow-derived and present antigen in vivo. Science. 1988;239:290–2. CrossRef
- Kato H, Kogure K, Liu XH, Araki T, Itoyama Y. Progressive expression of immunomolecules on activated microglia and invading leukocytes following focal cerebral ischemia in the rat. Brain Res. 1996;734:203–12. CrossRef
- Hathcock KS, Laszlo G, Pucillo C, Linsley P, Hodes RJ. Comparative analysis of B7-1 and B7-2 costimulatory ligands: expression and function. J Exp Med. 1994;180:631–40. CrossRef
- Jiang-Shieh YF, Yeh KY, Wei IH, et al. Responses of microglia in vitro to the gram-positive bacterial component, lipoteichoic acid. J Neurosci Res. 2005;82:515–24. CrossRef
- Lee SJ, Lee S. Toll-like receptors and inflammation in the CNS. Curr Drug Targets Inflamm Allergy. 2002;1:181–91. CrossRef
- Zanin-Zhorov A, Tal-Lapidot G, Cahalon L, et al. Cutting edge: T cells respond to lipopolysaccharide innately via TLR4 signaling. J Immunol. 2007;179:41–4.
- Manicassamy S, Ravindran R, Deng J, et al. Toll-like receptor 2-dependent induction of vitamin A-metabolizing enzymes in dendritic cells promotes T regulatory responses and inhibits autoimmunity. Nat Med. 2009;15:401–9. CrossRef
- Kerfoot SM, Long EM, Hickey MJ, et al. TLR4 contributes to disease-inducing mechanisms resulting in central nervous system autoimmune disease. J Immunol. 2004;173:7070–7.
- Kato N, Fujii Y, Agata N, et al. Experimental murine model for autoimmune myocarditis using Klebsiella pneumoniae O3 lipopolysaccharide as a potent immunological adjuvant. Autoimmunity. 1993;14:231–6. CrossRef
- Zaccone P, Fehervari Z, Blanchard L, Nicoletti F, Edwards CK 3rd, Cooke A. Autoimmune thyroid disease induced by thyroglobulin and lipopolysaccharide is inhibited by soluble TNF receptor type I. Eur J Immunol. 2002;32:1021–8. CrossRef
- Proft T, Fraser JD. Bacterial superantigens. Clin Exp Immunol. 2003;133:299–306. CrossRef
- Friedman SM, Tumang JR, Crow MK. Microbial superantigens as etiopathogenic agents in autoimmunity. Rheum Dis Clin North Am. 1993;19:207–22.
- Ivars F. Superantigen-induced regulatory T cells in vivo. Chem Immunol Allergy. 2007;93:137–60. CrossRef
- Romagnani S. Regulation of the T cell response. Clin Exp Allergy. 2006;36:1357–66. CrossRef
- Gee JM, Kalil A, Thullbery M, Becker KJ. Induction of immunologic tolerance to myelin basic protein prevents central nervous system autoimmunity and improves outcome after stroke. Stroke. 2008;39:1575–82. CrossRef
- Hofstetter HH, Targoni OS, Karulin AY, Forsthuber TG, Tary-Lehmann M, Lehmann PV. Does the frequency and avidity spectrum of the neuroantigen-specific T cells in the blood mirror the autoimmune process in the central nervous system of mice undergoing experimental allergic encephalomyelitis? J Immunol. 2005;174:4598–605.
- Muhallab S, Lidman O, Weissert R, Olsson T, Svenningsson A. Intra-CNS activation by antigen-specific T lymphocytes in experimental autoimmune encephalomyelitis. J Neuroimmunol. 2001;113:202–11. CrossRef
- Wang WZ, Olsson T, Kostulas V, Hojeberg B, Ekre HP, Link H. Myelin antigen reactive T cells in cerebrovascular diseases. Clin Exp Immunol. 1992;88:157–62. CrossRef
- Bornstein NM, Aronovich B, Korczyn AD, Shavit S, Michaelson DM, Chapman J. Antibodies to brain antigens following stroke. Neurology. 2001;56:529–30.
- Dambinova SA, Khounteev GA, Izykenova GA, Zavolokov IG, Ilyukhina AY, Skoromets AA. Blood test detecting autoantibodies to N-methyl-d-aspartate neuroreceptors for evaluation of patients with transient ischemic attack and stroke. Clin Chem. 2003;49:1752–62. CrossRef
- Dale RC, Candler PM, Church AJ, Wait R, Pocock JM, Giovannoni G. Neuronal surface glycolytic enzymes are autoantigen targets in post-streptococcal autoimmune CNS disease. J Neuroimmunol. 2006;172:187–97. CrossRef
- Fillit HM, Kemeny E, Luine V, Weksler ME, Zabriskie JB. Antivascular antibodies in the sera of patients with senile dementia of the Alzheimer's type. J Gerontol. 1987;42:180–4.
- Jankovic BD, Horvat J, Djordjijevic D, Ramah A, Fridman V, Spahic O. Brain-associated autoimmune features in heroin addicts: correlation to HIV infection and dementia. Int J Neurosci. 1991;58:113–26. CrossRef
- Braus BK, Hauck SM, Amann B, et al. Neuron-specific enolase antibodies in patients with sudden acquired retinal degeneration syndrome. Vet Immunol Immunopathol. 2008;124:177–83. CrossRef
- Ikeda Y, Maruyama I, Nakazawa M, Ohguro H. Clinical significance of serum antibody against neuron-specific enolase in glaucoma patients. Jpn J Ophthalmol. 2002;46:13–7. CrossRef
- Jankovic BD, Djordjijevic D. Differential appearance of autoantibodies to human brain S100 protein, neuron specific enolase and myelin basic protein in psychiatric patients. Int J Neurosci. 1991;60:119–27. CrossRef
- Dantzer R. Cytokine, sickness behavior, and depression. Immunol Allergy Clin North Am. 2009;29:247–64. CrossRef
- Imai T, Hieshima K, Haskell C, et al. Identification and molecular characterization of fractalkine receptor CX3CR1, which mediates both leukocyte migration and adhesion. Cell. 1997;91:521–30. CrossRef
- Umehara H, Bloom E, Okazaki T, Domae N, Imai T. Fractalkine and vascular injury. Trends Immunol. 2001;22:602–7. CrossRef
- Chapman GA, Moores K, Harrison D, Campbell CA, Stewart BR, Strijbos PJ. Fractalkine cleavage from neuronal membranes represents an acute event in the inflammatory response to excitotoxic brain damage. J Neurosci. 2000;20:RC87.
- Tarozzo G, Campanella M, Ghiani M, Bulfone A, Beltramo M. Expression of fractalkine and its receptor, CX3CR1, in response to ischaemia-reperfusion brain injury in the rat. Eur J Neurosci. 2002;15:1663–8. CrossRef
- Soriano SG, Amaravadi LS, Wang YF, et al. Mice deficient in fractalkine are less susceptible to cerebral ischemia-reperfusion injury. J Neuroimmunol. 2002;125:59–65. CrossRef
- Denes A, Ferenczi S, Halasz J, Kornyei Z, Kovacs KJ. Role of CX3CR1 (fractalkine receptor) in brain damage and inflammation induced by focal cerebral ischemia in mouse. J Cereb Blood Flow Metab. 2008;28:1707–21. CrossRef
- Kastenbauer S, Koedel U, Wick M, Kieseier BC, Hartung HP, Pfister HW. CSF and serum levels of soluble fractalkine (CX3CL1) in inflammatory diseases of the nervous system. J Neuroimmunol. 2003;137:210–7. CrossRef
- Matsunawa M, Isozaki T, Odai T, et al. Increased serum levels of soluble fractalkine (CX3CL1) correlate with disease activity in rheumatoid vasculitis. Arthritis Rheum. 2006;54:3408–16. CrossRef
- Yajima N, Kasama T, Isozaki T, et al. Elevated levels of soluble fractalkine in active systemic lupus erythematosus: potential involvement in neuropsychiatric manifestations. Arthritis Rheum. 2005;52:1670–5. CrossRef
- Fraticelli P, Sironi M, Bianchi G, et al. Fractalkine (CX3CL1) as an amplification circuit of polarized Th1 responses. J Clin Invest. 2001;107:1173–81. CrossRef
- Title
- CNS Immune Responses Following Experimental Stroke
- Journal
Neurocritical Care
Volume 12, Issue 2 , pp 274-284
- Cover Date
- 2010-04-01
- 10.1007/s12028-009-9270-4
- Print ISSN
- 1541-6933
- Online ISSN
- 1556-0961
- Publisher
- Humana Press Inc
- Additional Links
- Topics
- Keywords
- Stroke
- Toll-like receptor
- Autoimmune
- Th1
- Fractalkine
- Industry Sectors
- Authors
- Dannielle Zierath (1)
- Matthew Thullbery (1)
- Jessica Hadwin (1)
- J. Michael Gee (1)
- Anna Savos (1)
- Angela Kalil (1)
- Kyra J. Becker (1)
- Author Affiliations
- 1. Department of Neurology, University of Washington School of Medicine, Harborview Medical Center, Box 359775 HMC, 325 9th Ave, Seattle, WA, 98104-2499, USA


text:
(based on 14 reviews)
of respondents would recommend this to a friend.
Best Uses
Reviewed by 14 customers
Sort by
Displaying reviews 1-10
Back to top
Previous | Next »
Read While You Ride (On a trainer, only!)
By supercyclist
from NJ
About Me Avid Cyclist
Comments about Nashbar Reader Rack:
Well made product Could be deeper for this who still read old-fashioned books rather than on smartphones, Kindles, iPads, etc. Description reads, "Mounts easily to almost every bike out there." From other reviews and my experience, not accurate. However, that being said, put the attachment thingee out to pasture and use 3 - 4 wire ties in its place, and you're good to go. The attachment design needs to be rethought since, even if you have the perfect bar, it appears the attachment wouldn't be too secure.
Comment on this review
Works but...
By Barbelljimmy
from Rockford, IL
See all my reviews
I use this on my training bike to hold TV controllers,phone, iPad etc. I like most of the unit is solid. I do not like how it attaches to the bike. This is it weakest point. After many attempts, some electrical tape around my handlebar parts, I was able to get the unit to stay on. I would not trust it with a book however. Light items are OK. I may be able to figure something else out. I think another review talked about jamming a piece of wood though the section that hangs below the handle bar. Other than that, it works and does what it is advertised.
good product, bad fit
By blizzard wizard
from coventry, RI
About Me Casual/ Recreational
excellent rack for ipad or book on my indoor mounted bike but required velcro straps to secure it. What came with it did not work for me.
Great Boook/Magazine Holder
By Splashboy
from Hobe Sound, FL
This is a well-constructed reading material holder that attaches easily to my flat-bar handlebars on a Specialized Sirrus. Attachment to the bike took all of thirty seconds. It holds my books or magazines securely.
I wish it was better
By mbike traveller
from Myrtle Beach, SC and S. Korea
Wanted it for my stationary set in my basement. The mount system is not well designed. Works well only with thin books.
Hey - It's a tray that stays put
By dbee
from A Shoe
I needed to place a small piece of wood between the clamp and the neck but that works just fine.
Good product
By Petulo
from Central NJ
Sturdy and well made. Needs some improvising to attach it handlebars.
By athletic
from Central California
There are a lot of different products on the market for using your ipad or ereader while on the trainer. Those products are expensive. This is the perfect inexpensive solution to my boredom while cycling in my garage.
Why read a book? Use it for your iPad!
By Goose29
from Memphis, TN
I bought this bike to put on my mountain bike I keep on a trainer in the winter. I only use it for my iPad. Fits my mountain bike just fine, however the hand tightening system lacks a little bit. Could slip on smaller stems, but could also be compensated for with zip ties. You should keep your front wheel in a riser block when on the trainer to help keep any wobble to a minimum, making it easier to read while riding.
Works great!
By bynieves
from Irving, TX
The reader rack work perfectly with a stationary bike. It took a second to put on. It seems very stable. I still have plenty of room between the rack and the handlebars for my hands. It certainly makes riding a stationary bike not as boring when you can read at the same time.
Item No. » NB-RDR


text:
Financing for Restaurants
sponsored by: FireKingfeatured articles
industry headlines
Garbanzo Mediterranean Grill, a Denver-based fast casual restaurant concept featuring Mediterranean cuisine, opened its first urban location with t
GE Capital, Franchise Finance (GEFF) expanded its team of account executives to focus on developing relationships with the next generation of resta
Juice It Up!, one of the nation's largest raw juice bar and hand-crafted smoothie franchises, will discuss its substantial year-over-year sales gro
Revention Point of Sale Solutions is pleased to announce its integration with HotSchedules, an Austin-based company specializing in labor managemen
Driven by stronger same-store sales, customer traffic levels, and a more optimistic outlook among restaurant operators, the National Restaurant Ass
Cutting costs can be key to the survival of a restaurant operator, but not all are aware of the best options to do so.
Garden Fresh Restaurant Corp. announced that David A. Carr and Julie L.
An agreement was reached to create the world's third largest quick-service restaurant company. Tim Hortons Inc. and Burger King Worldwide Inc.
Buffalo Wild Wings Inc.
Popeyes Louisiana Kitchen Inc., the franchisor and operator of Popeyes restaurants, announced that William P.
- « first
- ‹ previous
- …
- 5
- 6
- …
- next ›
- last »


text:
The firms behind the projects honored in the ninth annual awards program leveraged building information modeling beyond design and documentation to actually model building information.
With the help of mobile technology, virtual reality offers promising architectural applications, Blaine Brownell reports.
As sustainable design becomes standard practice and energy monitoring becomes mandatory in more cities, architects will need to move the discussion beyond design to cover building performance as well. The AIA recently released a guidebook to help architects navigate through this potentially...
As an integrated design process becomes the norm and energy usage moves up in the priorities of a project, design teams must begin looking at energy early on.
This cloud-based collaboration program allows anyone with a Web browser to view 2D and 3D files without the native software.
Autodesk's vice president of strategic industry relations shares how architects can avoid obsolescence.
The new Sweets App is an all-in-one mobile source for building products, CAD details, and BIM objects.
Software is crucial to design, but a program is only part of the story. Plug-ins, updates, and other customizations are key to getting work done.
Energy modeling is for everyone and all buildings benefit.
Building Information Modeling has to keep up if it's going to remain on top.


text:
Stewart W. Gary, MPA, Principal |
W. Gary, MPA, Principal, leads Citygate's Fire
Services practice. Chief Gary has 42 years of experience in the
fire service,
including 5 years as a paramedic. In 1994 he was appointed Chief
of the Livermore Fire Department, in Alameda County, California,
and in 1996, he successfully designed and led the implementation
of the Livermore-Pleasanton fire department consolidation, which
subsequently won a California League of Cities Helen Putnam award.
The Livermore-Pleasanton Fire Department today is one of the
few successful city-to-city fire mergers in California. Chief
retired as Chief of the combined department. For the past 16 years, he also has been the lead instructor and program content developer for the Standards of Coverage process. He annually taught a 40-hour course on this systems approach for fire deployment at the California Fire Academy and consults across the United States and Canada on the Standards of Response Coverage process. Chief Gary has both a bachelor's and master's degree in Public Administration from San Diego State University. In addition, he holds an Associate in Fire Science degree from Miramar Community College in San Diego. He is a past-president of the League of California Cities Fire Chiefs Department, has served as the Fire Chief member on the League of California Cities Board of Directors and was a member of the State of California Office of Emergency Services (OES) Firescope Board of Directors. Chief Gary has held memberships in the California Fire Chiefs Association, the National Fire Protection Association, and the International Association of Fire Chiefs. He writes for fire service publications on deployment and fire service technology adoption issues. |
General Management Consulting | Fire Protection and Emergency Medical Services | Public Safety (Law Enforcement) Maximizing Human Capital Assets | Leadership Development, Team Building, and Coaching | Executive Search and Recruitment Community Development | Animal Care and Control | Strategic Planning | Emergency Management and Operations Training |