1,574 research outputs found
Annular honeycomb seals: Test results for leakage and rotordynamic coefficients; comparisons to labyrinth and smooth configurations
Test results are presented for leakage and rotordynamic coefficients for seven honeycomb seals. All seals have the same radius, length, and clearance; however, the cell depths and diameters are varied. Rotordynamic data, which are presented, consist of the direct and cross-coupled stiffness coefficients and the direct damping coefficients. The rotordynamic-coefficient data show a considerable sensitivity to changes in cell dimensions; however, no clear trends are identifiable. Comparisons of test data for the honeycomb seals with labyrinth and smooth annular seals show the honeycomb seal had the best sealing (minimum leakage) performance, followed in order by the labyrinth and smooth seals. For prerotated fluid entering the seal, in the direction of shaft rotation, the honeycomb seal has the best rotordynamic stability followed in order by the labyrinth and smooth. For no prerotation, or fluid prerotation against shaft rotation, the labyrinth seal has the best rotordynamic stability followed in order by the smooth and honeycomb seals
Towards a Reference Architecture of Intent for Information Systems Strategic Alignment
Enterprise architecture enables strategic alignment through creation of a unified business and IS view of the target state of the business. Using a design science approach, this paper proposes an intent-based technique as an extension to existing modeling techniques for strategic alignment. The proposed approach defines a reference architecture of enterprise intent that includes vocabulary, rules, and structure for development of purposefully aligned strategic-level enterprise architecture. The proposed approach results in interacting hierarchies that can be analyzed through network science approaches
Improving the Alignment Between IT Projects and Strategic Initiatives: The Target State Specfic Outcome (TSSO) Method
There is little direct evidence that information systems (IS) deliver measurable value at the organizational level. This inability to measure IS value is often caused by an inability to directly allocate beneficial financial outcomes to IS. Therefore, an alternative approach to determining IS value is required. This paper builds on Kaplan and Nortonâs third-generation balanced score card to measure IS value. The authors propose a causal Target State Specific Outcome (TSSO) model to achieve the required IS alignment with strategic initiative objectives and measures
Forum Guest Editorsâ Introduction: Disability Studies in Education âAt Workâ
This introductory article serves as the springboard for a greater discussion of the question: How applicable are the ideas of Disability Studies in Education to educational policy and the practice of teaching? As guest editors of the special forum of RDS, we illustrate how DSE continues to inform educational theory, research, policy, and practice. First, we chronicle the rapid growth of DSE over the past decade. Second, as educators of teachers, we raise three topics to contemplate further for our field: (1) improving the relationship between science and ethics, (2) better connecting knowledge, beliefs, and values to practice, and (3) determining the position of DSE scholars within the field of special education. Third, we briefly highlight the four featured articles from Belgium, New Zealand, Scotland, and the USA that constitute this special forum. Finally, we urge the field of education to be more critical of special education practices and continue to be receptive toward DSE
Education for Cyber Crime Investigators
Digital forensics and cyber crime investigations are continually growing, rapidly changing fields requiring law enforcement agencies to meet very rigorous training requirements. New opportunities for committing criminal activity against persons, organization or property are presented every day with the proliferation of personal digital devices, computers, the internet, computer networks, and automated data systems. Whether the crime involves attacks against computer systems, electronic information, or more traditional crimes such as murder, money laundering or fraud, electronic evidence is becoming more prevalent. It is no surprise that law enforcement and criminal justice officials are being overwhelmed by the volume of investigations and prosecutions that involve electronic evidence. Fortunately, processes and procedures, as well as a variety of software and hardware tools have been developed to speed up and standardize the recovery of evidence from suspect media. Each of these tools provides specific capabilities within certain specialized areas. Training in the proper use of these tools is crucial for recovering forensically sound evidence in a manner which will withstand legal scrutiny. It is crucial for the success of future criminal investigations that the law enforcement community has access to timely, inexpensive, and readily available digital forensics and cyber crime investigations training material. This paper describes the development of a modular educational curriculum for training entry-level criminal investigators in the skills necessary to conduct a cyber crime scene investigation and evidentiary collection through the use of digital forensic tools. The curriculum incorporates multiple training methodologies, including instructor-led and multimedia based coursework. The curriculumâs instructor-led portion uses a classroom style presentation that provides 8-hours of interactive coursework. The participants are engaged in the actual process of evidence collection and a limited presentation on the uses of the forensic tools that are available to them. Additionally, the coursework is scaled to the userâs experience level, broken down to three levels: introductory, intermediate and advanced. The multimedia based coursework is designed to be scalable to a law enforcement agencyâs needs. The agency has the ability to select from a list of modular curriculum that targets specific needs of an investigator. In addition to the modular framework of the multimedia course, levels of experience are also incorporated. The multimedia coursework will allow the user to actually engage interactively with the materials, simulating a hands-on investigation. This curriculum offers multiple delivery options that law enforcement agencies can take advantage of, regardless of size or geographical disposition. The material in both the instructor-led and multimedia courses are updated to remain timely and keep the userâs well versed in the latest use of tools and procedures, insuring the investigative and evidentiary process remain intact.
Keywords: digital forensics, law enforcement, educatio
Lab Fattening and Non-invasive Estimates of Body Composition in Deer Mice
Total body electrical conductivity measurements and lipid composition were determined for the deer mouse (Peromyscus maniculatus) to derive species specific calibration equations for use with EM-SCAN estimates of lean and fat tissue. For each individual, total body electrical conductivity was measured by EM-SCAN, and actual lipid content was determined by chemical extraction. Then, using estimated and actual lipid values, separate calibration equations were generated for freshly captured (lean) and laboratory maintained (fat) individuals, and a combined equation was derived for all individuals. These equations were variable in the accuracy of lipid estimates; the lowest relative error estimate (percent body fat) was obtained with the equation for fat individuals while the highest error (percent body fat) was associated with the lean condition. Although high average error rates for lipid might preclude the use of this approach when absolute accuracy is necessary with lean individuals, estimates of lean tissue were very accurate regardless of body composition condition. When removed from the field and maintained in the laboratory, body composition changed significantly and quite rapidly with relative body fat doubling in six weeks. Thus, maintenance under laboratory conditions might affect physiologic and behavioral parameters in such subjects
Tunable, Highly Stable Lasers for Coherent Lidar
Practical space-based coherent laser radar systems envisioned for global winds measurement must be very efficient and must contend with unique problems associated with the large platform velocities that the instruments experience in orbit. To compensate for these large platform-induced Doppler shifts in space-based applications, agile-frequency offset-locking of two single-frequency Doppler reference lasers was thoroughly investigated. Such techniques involve actively locking a frequency-agile master oscillator (MO) source to a comparatively static local oscillator (LO) laser, and effectively producing an offset between MO (the lidar slave oscillator seed source, typically) and heterodyne signal receiver LO that lowers the bandwidth of the receiver data-collection system and permits use of very high-quantum-efficiency, reasonably- low-bandwidth heterodyne photoreceiver detectors and circuits. Recent work on MO/LO offset locking has focused on increasing the offset locking range, improving the graded-InGaAs photoreceiver performance, and advancing the maturity of the offset locking electronics. A figure provides a schematic diagram of the offset-locking system
Towards Redaction of Digital Information from Electronic Devices
In the discovery portion of court proceedings, it is necessary to produce information to opposing counsel. Traditionally, this information is in paper form with all privileged information removed. Increasingly, the information requested during discovery exists in digital form and savvy counsel is requesting direct access to the original digital source: a broad spectrum of additional digital information can be often be extracted using digital forensics. This paper describes the major problems which must be solved to redact digital information from electronic devices. The primary hurdle facing digital redaction is the lack of a rational process for systematically handling encoded, encrypted, or otherwise complex data objects. Any such process would need to incorporate a method for validating the integrity of electronic or digital redaction processes.
Keywords: digital forensics, redaction, electronic discovery, legal production, privileg
Near and mid-IR sub-arcsecond structure of the dusty symbiotic star R Aqr
The results of a high-resolution interferometric campaign targeting the
symbiotic long-period variable (LPV) R~Aqr are reported. With both
near-infrared measurements on baselines out to 10m and mid-infrared data
extending to 32m, we have been able to measure the characteristic sizes of
regions from the photosphere of the LPV and its extended molecular atmosphere,
out to the cooler circumstellar dust shell. The near-infrared data were taken
using aperture masking interferometry on the Keck-I telescope and show R~Aqr to
be partially resolved for wavelengths out to 2.2 microns but with a marked
enlargement, possibly due to molecular opacity, at 3.1 microns. Mid-infrared
interferometric measurements were obtained with the U.C. Berkeley Infrared
Spatial Interferometer (ISI) operating at 11.15 microns from 1992 to 1999.
Although this dataset is somewhat heterogeneous with incomplete coverage of the
Fourier plane and sampling of the pulsation cycle, clear changes in the
mid-infrared brightness distribution were observed, both as a function of
position angle on the sky and as a function of pulsation phase. Spherically
symmetric radiative transfer calculations of uniform-outflow dust shell models
produce brightness distributions and spectra which partially explain the data,
however limitations to this approximation are noted. Evidence for significant
deviation from circular symmetry was found in the mid-infrared and more
tentatively at 3.08 microns in the near-infrared, however no clear detection of
binarity or of non-LPV elements in the symbiotic system is reported.Comment: Accepted to Astrophysical Journal. To appear in volume 534. 14 pages;
3 postscript figure
One-Antigen Mismatched Related versus HLA-Matched Unrelated Donor Hematopoietic Stem Cell Transplantation in Adults with Acute Leukemia: Center for International Blood and Marrow Transplant Research Results in the Era of Molecular HLA Typing
Approximately 13% of patients lacking an HLA-identical sibling have a one-antigenâmismatched related donor (MMRD). Historically, outcomes from the use of a one-antigen MMRD were considered equivalent to those from the use of a matched unrelated donor (UD). Recent improvements in UD stem cell transplantation (SCT) resulting from better molecular HLA matching justifies investigating whether UD should be preferred over MMRD in adult patients with acute leukemia. Here, we compared the outcomes of MMRD (n = 89) and HLA-A, -B, -C, and -DRB1 alleleâmatched UD (n = 700) SCT reported to the Center for International Blood and Marrow Transplant Research between 1995 and 2005. The patients underwent transplantation for acute myelogenous leukemia or acute lymphoblastic leukemia in first or second complete remission. Donor type was not associated with hematologic recovery. Univariate and multivariate comparisons of MMRD versus HLA-matched UD transplants showed no statistically significant differences in overall survival, disease-free survival, treatment-related mortality, relapse, or 100-day grade III-IV acute graft-versus-host disease (GVHD). MMRD SCT was associated with a lower rate of chronic GVHD at 1 year (35% vs 47%; P = .03), which was confirmed by multivariate analysis (relative risk, 0.58; 95% confidence interval, 0.39-0.85; P < .01). According to our data, HLA-matched UD and MMRD SCT are associated with comparable survival. Given that less chronic GVHD was observed in the MMRD transplantations, this option, when available, remains the first choice in patients with acute leukemia without an HLA-identical sibling in need of allogeneic SCT
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