Acquisition Station Research Articles

Intrusions and anomalous Vp/Vsratios associated with the New Madrid seismic zone

DetailedPwave velocity (Vp) andSwave velocity (Vs) models and Vp/Vsratios were determined for a major portion of the New Madrid seismic zone using arrival times recorded by the New Madrid seismic network and Portable Array for Numerical Data Acquisition (PANDA) stations. We performed a simultaneous inversion forPandSwave velocities and hypocentral locations, yielding the most detailed tomographic image of the upper portion of the crust to date. Low Vpand high Vsanomalies resulted in low Vp/Vsratios that correspond to the major arms of seismicity north of the intersection of the Cottonwood Grove–Blytheville Arch (CG‐BA) fault with the Reelfoot fault. The unusual low Vp/Vsvalues can be attributed to the presence of quartz‐rich rocks. Two regions contain anomalous Vpand Vsvalues and Vp/Vsratios that cannot be attributed to variations in rock composition and are probably produced by overpressured fluids. One region is located on the hanging wall of the northern portion of the Reelfoot fault and is aseismic. The other region corresponds to a portion of the southern Reelfoot fault that experiences swarm activity. A distinct velocity contrast exists across the CG‐BA fault at depths exceeding 4.65 km; basement rocks southeast of the fault have Vpvalues that are 4%–6% slower than values for rocks located to the northwest. The most logical explanation is that the fault follows a preexisting structural feature or lithologic change in basement rocks.

Developing brain electric activity acquisition software for Linux

This article discusses the first successful phase of our work on the construction of a complete modular research station for EEG signal acquisition and analysis performed in real-time mode and in a way that meets our needs. Our intentions were presented in [1].

Data access and its implementation at Wendelstein 7-X

The increasing number of data acquisition stations and setups in laboratory environments at Wendelstein 7-X does already produce a considerable amount of data by now. Diagnosticians want to view the acquired data in a comfortable way and use them for calculations in their own test and analysis algorithms. To prepare for full operation of W7-X, a reasonable approach is to provide data access methods that stay as close as possible to the final data access concept. This requires taking care of the special needs of W7-X regarding continuously acquired data, segment based parameter switching and synchronization of data from different diagnostics. Therefore, a data access interface has been designed and implemented considering continuous data acquisition as well as usability and performance issues. The interface and its usage in different software environments (e.g. high level scientific programming languages) will be explained. Also, the integration of user defined off line analysis algorithms will be described. Additionally, the DataBrowser will be presented. The DataBrowser is a Java application that can browse continuously acquired data of different kind, provides several types of plots including zooming functions to display the data and the corresponding parameters and offers export functions to save selected data locally.

A VLSI ASIC front end for the optical module of the NEMO underwater neutrino detector

The work described here has been developed in the context of the NEMO Collaboration with the aim of studying and designing a front-end electronics for the Optical Modules, which contains the telescope optical sensors, as a full-custom Very Large Scale Integration (VLSI) Application Specific Integrated Circuit (ASIC). The solution has a multitude of advantages. The most important are low power consumption and the pre-analysis and suitable reduction of data to be transferred to the shore station for acquisition. A detailed description of the chosen architecture and the design principles of the blocks, that carry out the specialized function required by this architecture, will be given. The chips produced will be described and the test measurements performed will be shown.

WE-D-330D-02: Non-Ideal Behavior of DR Systems

Ideally, we would like for clinical digital radiography (DR) systems to produce faithful reproductions of radiographic projections, acquired at optimum gain, and rendered appropriately for diagnostic interpretation. We also expect uniform performance from identical DR systems. We would like DR systems to maintain their optimum performance indefinitely, or at least to alert us when their performance falls below reasonable limits. We expect DR systems to be user‐friendly, to accommodate operator Quality Control (QC) activities, and to enable the operator to correct errors without the need for a repeated exposure. In reality, all DR systems fall short of these ideal expectations. Awareness of causes and corrective actions for non‐ideal behavior is important for Medical Physicists in order to assist clinical practice with DR. The talk will consider the effects of discrete detector elements, gain compensation maps, and “ghost” images on acquisition of the radiographic projection. Variation in gain and SNR with exposure will be discussed. Sources of interferences with image segmentation will be described including hardware, shielding, and the challenge of large and small patients. The influence of operator technical errors will be explored. The value of automated quality control self‐tests in assessing and maintaining optimum performance will be examined. The ability of the operator to intervene in the event of a sub‐standard image will be considered. Positive and negative aspects of operator modification will be mentioned. Discrepancies between display functions at the acquisition station and at the physician's diagnostic display will be discussed. Learning Objectives: 1. Appreciate the technological limitations on ideal behavior by DR systems. 2. Understand the clinical manifestations of non‐ideal DR behavior. 3. Identify actions that can reveal or correct non‐ideal DR behavior.

A VLSI ASIC front end for the optical module of the NEMO underwater neutrino detector

The work described here has been developed in the context of the NEMO Collaboration with the aim of studying and designing a front-end electronics for the Optical Modules, which contain the telescope optical sensors, as a full-custom Very Large Scale Integration (VLSI) Application Specific Integrated Circuit (ASIC). The solution has a multitude of advantages. The most important are low power consumption and the preanalysis and suitable reduction of data to be transferred to the shore station for acquisition. A detailed description of the chosen architecture and the design principles of the blocks, that carry out the specialized function required by this architecture, will be given. The chips produced will be described and the test measurements performed will be shown.

The Importance of Time Synchronization in the Local Networks of the Science and Application Center for Lunar and Deep‐space Exploration

Abstract The data acquisition stations and the data processing center of the Science and Application Center for Lunar and Deep‐space Exploration (SACLuDE) are located at different geographical sites. They respectively have their own local networks and interconnect with each other through access to the core data network. This paper describes the clock drift in the computer and other networked devices building up the infrastructure of the above local networks. The network time variance of the stochastic model is also estimated. The poor precision of network synchronization will bring about potential hazards to the network operation and application running in the networks, which is clarified in the present paper. At the end of the paper, a cost‐effective and feasible solution is proposed based on the Global Position System (GPS) and the Network Time Protocol (NTP).

Three‐dimensional P wave velocity structure in the New Madrid seismic zone

A three‐dimensional P wave velocity model for the New Madrid seismic zone (NMSZ) has been developed using a nonlinear travel time tomography method. The inversion involved 709 earthquakes recorded by digital, three‐component Portable Array for Numerical Data Acquisition stations deployed in the NMSZ over the time period 1989 through 1992. Analysis of ray coverage and inversion of a synthetic data set showed that the model has high resolution to a depth of 11 km. Low‐velocity anomalies correlate with the prominent northwest and northeast trending arms of seismicity. Lowest‐velocity anomalies (−8%) occur at the intersection of these arms and are associated with shallow seismicity and a high swarm rate. These low‐velocity regions are interpreted to be the result of increased fluid pressure associated with structurally disrupted rocks beneath the Blytheville‐Pascola arch complex. Small regions of high velocity, limited to the upper few km of the crust, correlate with gravity and magnetic anomalies and are interpreted to be igneous intrusions. High‐velocity anomalies also parallel the edges of the Reelfoot rift margin and probably are associated with crystalline Precambrian rocks that form the margin of the Reelfoot rift graben. Most earthquakes are associated with low‐velocity regions and avoid regions of high velocity.

Scientists jump on the Santa bandwagon

While many government scientists may have been home with their families during the Christmas holiday, a hardy few—at no cost to taxpayers—apparently helped Santa Claus and tracked him on his rounds.Through its Satellite Command and Data Acquisition Station in Fairbanks, Alaska, the U.S. National Oceanic and Atmospheric Administration (NOAA) maintained a satellite watch of the North Pole for weather conditions and unusual activity Meanwhile, NOAA's National Climatic Data Center in Asheville, North Carolina, created an online snow report for Santa, which contains maps and tables showing percentage probabilities for various snow depths on Christmas morning.

Automated Firearms Evidence Comparison: A Forensic Tool for Firearms Identification—An Update

Abstract The Bureau of Alcohol, Tobacco and Firearms (ATF) laboratories is applying the new technology of computerized image analysis for the identification of bullets and cartridge casings recovered in open cases, and to a database of test fired weapons. The Integrated Ballistic Identification System (IBIS) accomplishes these comparisons in minutes, when the same task using conventional microscopical techniques would require weeks to carefully sort through the firearm evidence. The networking of remote Data Acquisition Stations (DAS) can build a regional firearms evidence database, making the IBIS a powerful resource for the investigation of violent firearm crimes from multiple jurisdictions. A technical overview of the IBIS image acquisition hardware, image storage, case data input, “surface signature” analysis, and correlation scoring to an image database is reported.

Environmental conditions in high mountain lakes containing toxic benthic cyanobacteria

In glacial lakes on an alpine pasture in Switzerland, benthic cyanobacteria produced microcystin, a cyclic hepatotoxic heptapeptide. The cyanobacteria formed dense mats on sediments and submerged stones. The mats consisted mainly of Oscillatoria limosa, Phormidium konstantinosum (= Oscillatoria tenuis) and Tychonema granulatum (= Oscillatoria granulata). In order to characterize the ecological conditions of these cyanobacteria, nutrient concentrations were determined, and an automatic data acquisition station was installed in one of the lakes. It continuously recorded air temperature, global irradiance, precipitation, atmospheric pressure, wind speed and direction; as well as temperature, pH, oxygen content and conductivity of the lake water. The nutrient situation in the lakes was mainly influenced by the erosion of the gneissic catchment by glacial meltwater and by precipitation. In the glacial lakes, the concentrations of calcium, iron, magnesium, sodium and sulphate increased throughout the summer season. Conductivity values of 4–110 µS cm-1 represent generally low nutrient concentrations. Nevertheless, iron concentrations of up to 20 µM occurred. Biomass, expressed as protein concentration, as well as the microcystin content of the cyanobacterial mats varied within one season and between different years (1994 and 1995). In one cyanobacterial mat community, biomass and microcystin concentrations were highest at the same time, in an other one the microcystin content was maximal three weeks after the highest biomass concentration was reached. Our observations suggest that biomass and toxin production in the mats were strongly influenced by mechanical stress, temporary desiccation and high irradiation.

Technical Issues Related to Digital Stress Echocardiography Analysis and Acquisition Stations.

Digital acquisition and display of echocardiographic images has facilitated the development of stress echocardiography. This review will outline technical issues involved with digital capture and manipulation of echocardiographic data, referring to currently available commercial equipment. Among the acquisition items to be discussed are the source of the digitized data (direct digital transfer from the echo machine vs video capture); image resolution (spatial and temporal spacing of the digitized data); and EKG triggering options (direct triggering of the QRS complex vs detecting the QRS on the video transfer). During playback, rest and stress images may be displayed at different frame rates, so that systole will occupy approximately the same time interval. Currently available commercial systems are compared with regard to these features, as well as hardware architecture and operating system.

Use of small stand-alone Internet nodes as a distributed control system

For several years, the standard model for accelerator control systems has been workstation consoles connected to VME local stations by a Local Area Network with analog and digital data being accessed via a field bus to custom I/O interface electronics. Commercially available hardware has now made it possible to implement a small stand-alone data acquisition station that combines the LAN connection, the computer, and the analog and digital I/O interface on a single board. This eliminates the complexity of a field bus and the associated proprietary I/O hardware. A minimum control system is one data acquisition station and a Macintosh or workstation console, both connected to the network; larger systems have more consoles and nodes. An implementation of this architecture is described along with performance and operational experience.

A continuous monitoring system for blood glucose measurements in conscious animals without surgery

AbstractThe hypoglycemic activity of insulin delivered via the various routes is commonly determined by measuring glucose levels in the whole blood samples taken intermittently at frequent intervals. This procedure is usually performed in the anaesthetized animals, however, the glucose levels determined could be higher than those in the conscious animals. Furthermore, the animals are usually excited by direct contact with the investigator during the frequent blood sampling in conscious state, which could cause the glucose level to be higher than at undisturbed state. To overcome these problems, a continuous blood glucose monitoring system was developed by connecting the sensor chamber of a glucose analyzer (YSI Industrial Analyzer model 27), which utilizes glucose oxidase for glucose measurement, to a peristaltic pump with a specially designed mixing chamber and a data acquisition station. By using this system, the hyper-/hypoglycemic activity of glucagon/insulin formulations in the conscious animals, aft...

A Continuous Monitoring system for Blood Glucose Measurements in conscious Animals without Surgery

AbstractThe hypoglycemic activity of insulin delivered via the various routes is commonly determined by measuring glucose levels in the whole blood samples taken intermittently at frequent intervals. This procedure is usually performed in the anaesthetized animals, however, the glucose levels determined could be higher than those in the conscious animals. Furthermore, the animals are usually excited by direct contact with the investigator during the frequent blood sampling in conscious state, which could cause the glucose level to be higher than at undisturbed state. To overcome these problems, a continuous blood glucose monitoring system was developed by connecting the sensor chamber of a glucose analyzer (YSI Industrial Analyzer model 27), which utilizes glucose oxidase for glucose measurement, to a peristaltic pump with a specially designed mixing chamber and a data acquisition station. By using this system, the hyper-/hypoglycemic activity of glucagon/insulin formulations in the conscious animals, aft...

PV powered stand-alone data acquisition systems

The interest of Photovoltaic Solar Energy for powering stand-alone installations is evidence, and especially analysed in the case of data acquisition stations. A general description of the various possible systems to be inserted between the PV array and the load(s) is given. Some examples are described. In the specific case of an application to a large Air Shower Array for the detection of high energy cosmic ray, site constraints are considered, as well as energy conversion performances.

A design for a Picture Archiving Communication System central storage facility

A Picture Archive and Communication System (PACS) as it is to be used in a Hospital will consist of a number of workstations, data acquisition stations and output stations, connected to a central storage facility. In this paper the architecture of the central storage facility is studied, and an implementation is proposed. Simulation studies have been performed on the proposed implementations, showing their feasibility. The simulation studies show that the central storage facility can store over 500 sets on a daily basis, while simultaneously handling the review and output activity associated with such a production. On the average, each set is assumed to consist of 3 images of 4 Mbyte each. Simulation results are presented for a number of alternative systems. Special attention is given to the implications of prefetching on the protocols to be used in the PACS system. It is shown that prefetching, in particular in combination with a pipelined system, can yield significant performance benefits. We believe that prefetching of images is a prerequisite for good system performance. The implementation assumes that a high-speed communication protocol is used to interconnect the PACS components. The paper will not go into details on the network considerations. The central storage facility is designed using a general purpose System/370 machine, with the peripherals commonly used for such machines. This implies that it can be realized with currently available equipment. Several alternative implementations using interconnected workstation based systems are suggested.

Modernization of the MX-1321 mass-spectrometer: A new information system for GC/MS analysis

Abstract A new informatic system for the MX-1321 mass-spectrometer is described. The system includes a specialized station for acquisition and initial selection of data, and a PC AT computer. The main tasks of the system are cyclic scanning of spectra during GC/MS analysis, acquisition and conversion of data in real time to a mass spectrum (nominal mass-amplitude form) and saving data on a hard disc. The system, without any major modification, can be used to update other types of mass-spectrometers or be incorporated into measuring assemblies that feature high-frequency sampling from a few separate channels. Since the system has built-in clocks, it is especially suited to handling devices operating periodically.

An investigation of the meaning of near and close on a university campus

An experimental study of the geographic natural language concepts near and close is presented. Using the Spatial Relations Acquisition Station, two groups of subjects were asked whether they believed particular buildings on the campus of Kent State University to be either near or close to one central building, the Student Center. Three clusters can be identified among the subjects responding for the concept near, and from analysis of the close data direct parallels can be identified. One cluster of each term shows all buildings to be near or close to the Student Center, while, at the other extreme, another cluster shows all but a core group to be not-near. A number of personal characteristics were gathered for subjects in the study, but none gave a significant prediction of which cluster a student might belong to.

Heterogeneous computer network for real-time hemodynamic signal processing

A computer network is described that allows real-time processing, graphical monitoring and off-line analysis of blood pressure, nervous activity and Doppler signals recorded in conscious rats. Real-time processing is performed by an acquisition station using a powerful microprocessor, allowing extraction and storage of several characteristic parameters from each cardiac cycle and real-time graphical monitoring. The experimenter can thereby follow the time evolution of the hemodynamic parameters. Experimental data are sent through the local network to a workstation that ensures off-line processing such as chronograms, histograms and statistical analyses.