Miami University, Ohio
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Compressed Bit-sliced Signature Files An Index Structure for Large Lexicons
Get PDFWe use the signature file method to search for partially specified terms in large lexicons. To optimize efficiency, we use the concepts of the partially evaluated bit-sliced signature file method and memory resident data structures. Our system employs signature partitioning, compression, and term blocking. We derive equations to obtain system design parameters, and measure indexing efficiency in terms of time and space. The resulting approach provides good response time and is storage-efficient. In the experiments we use four different lexicons, and show that the signature file approach outperforms the inverted file approach in certain efficiency aspects.
KEYWORDS: Lexicon search, n-grams, signature files
Implementation of the Interview Scheduling System for Miami University's Career Planning and Placement Office
Get PDFThis project is an extension of systems analysis and design cavered in two classes - SAN 4721572 (Analysis of Infcwmation Systems) and SAN 4751575 (Structured Design and Implementation). My implementation involved work in the areas of integrating a subset of the system, designing a multiuser accessing means, investigating database security, implementing
dynamic calls, setting-up a database load facility, and researching laser printers and forms software. The integration involved getting the system to an operational state as opposed
to a production state. Multiuser access to the system will be permitted to about 2600 Seniors and accounting Juniors. The students will be permitted to access the system simultaneously,
and SQL will provide the concurrency control. The database security will be upheld by offering authority privilege to the program instead of the users. Dynamic calls will be used to maintain a reasonable virtual machine size. A database load facility will be used by the DBA at the beginning of every year to load demographic data pertaining to students, The standard resumes will be printed by the CPPO and that will require a new laser and a forms software. Research has been completed for various lasers and forms software, and a recommendation is given. The final portion of the paper presents some of the benefits that 1 have obtained while working on this project
Signature File Hashing Using Term Occurrence and Query Frequencies
Get PDFSignature files act as a filter on retrieval to discard a large number of non-qualifying data items. Linear hashing with superimposed signatures (LHSS) provides an effective retrieval filter to process queries in dynamic databases. This study is an analysis of the effects of reflecting the term occurrence and query frequencies to signatures in LHSS. This approach relaxes the unrealistic uniform frequency assumption and lets the terms with high discriminatory power set more bits in signatures. The simulation experiments based on the derived formulas explore the amount of page savings with different occurrence and query frequency combinations at different
hashing levels. The results show that the performance of LHSS improves with the hashing level and the larger is the difference between the term discriminatory power values of the terms, the higher is the retrieval efficiency. The paper also discusses the benefits of this approach to alleviate the imbalance between the levels of efficiency and relevancy in unrealistic uniform frequency assumption case
Mitigation of GPS Multipath Using Polarization and Spatial Diversities
Get PDFThis paper presents a GPS multipath mitigation method using a dual circularly polarized antenna array and a multi-channel receiver. The method is based on the exploitation of both polarization and spatial diversity associated with a GPS signal and its multipath signals available at the receiver input. Conventional GPS antennas are right-hand circularly polarized (RHCP) to suppress multipath contributions to the input. This polarization-based discrimination of multipath signal cannot completely eliminate multipath induced GPS range measurement errors. We present an algorithm that performs spatial processing on the input from the left-hand circular polarized (LHCP) array with an increased relative strength of the multipath signal, thereby providing improved multipath angle of arrival (AOA) estimation. With the known multipath AOA and direct signal AOA (which can be obtained from almanac/ephemeris together with the antenna attitude or estimated in a separate process), we can then take advantage of the spatial diversity of the direct signal and multipath by applying null-steering to the RHCP array input. The paper presents the algorithm and simulation results for a uniform linear array receiving one direct signal and one multipath. Our preliminary studies showed that the multipath AOA estimator produces negligible error if the direct signal and multipath AOA are not close to each other (more than 5 degrees apart) and that the direct signal is not at low elevation. The results also suggested that longer time delay between the direct and multipath signal will increase multipath AOA estimation error but this increase is tolerable. Furthermore, we demonstrated that the multipath estimation improves with increasing spatial diversity for multipath and direct GPS signals even if the signal arrivals are close in time. Finally, we demonstrated that the multipath mitigation technique does produce an improved receiver correlator function which directly impacts the GPS code range measurement accurac
Worker Injuries and Safety Equipment in Ohio Nursing Homes
Get PDFA survey of nursing homes was conducted in 2006 to evaluate a number of facility-specific characteristics including worker injury rates. The nursing home worker injury rate was 6.6 per 100 workers with higher injury rates observed in larger facilities, homes that were part of chains and homes with a higher proportion of wheelchair bound residents. A broad range of patient-transfer safety equipment was observed to be in use; however, the presence of these devices were not predictive of lower worker injury rates
Enhancing the Performance of Local Long-Term Care Ombudsman Programs in Ohio: Chartbook
Get PDFThis is a state-level case-study of the performance of local Long-Term Care Ombudsman Programs in Ohio. In surveying all of the local program directors in Ohio, along with a group of key informants, we identify major strengths and challenges the program is likely to face in the future. Funding and staffing emerge as prominent issues, particularly in determining the longer-term educational and advocay roles these programs ideally fulfill
Graphical Programming of Simulation Models in an Object-Oriented Environment
Get PDFGraphical programming has been used in conjunction with
conventional simulation languages via block diagrams or activity
networks. Its beneficial effects on programming and modeling in
simulation have been accepted by everyone involved in these
languages. However, none of these conventional techniques is
truely interactive. Given the level of the current hardware and
software technology, it is possible to design a very good
graphical programming system which supports an interactive
incremental programming style in specifications of simulation
models. The benefit of such a visual system would go beyond the
modeling phase of a simulation study and it might as well be
realized in understanding the behavior of complex problems, in
being a communication and training medium for the user and
developers, and finally in presenting the simulation results.
In this study, the graphical programming methodology has
been investigated from the perspective of object-oriented
simulation. The truely interactive and graphical orientation of
some of the object-oriented languages (e.g., Smalltalk-80) has
opened up new avenues of research in this very important topic.
Today, the nature of this type of research will be not whether it can be done but how the known techniques should be combined to yield the highest benefit
Application of Object-oriented Programming in Simulation: A Simulation of Case Study Using Microsoft Visual C++
Get PDFIn this thesis, a prototype simulation environment is introduced. Simulation has always been important for systems analysis. The original idea of this thesis stems from
the fact that more flexible simulation programming tools are required by the modern analysis. Six simulation classes are implemented in the thesis to support simple simulation
cases and Microsoft Visual C++ window classes are used to build a user friendly interface. A simulation output class is also implemented to conduct simple simulation output analysis.
Based on this work, more classes and features can be added to make the simulation environment more powerful, so that the simulation environment can support different simulation situations
Neural Network Development for the Forecasting of Upper Atmosphere Parameter Distributions
Get PDFThis paper presents a neural network modeling approach to forecast electron concentration distributions in the 150â 600 km altitude range above Arecibo, Puerto Rico. The neural network was trained using incoherent scatter radar data collected at the Arecibo Observatory during the past two decades, as well as the Kp geomagnetic index provided by the National Space Science Data Center. The data set covered nearly two solar cycles, allowing the neural network to model daily, seasonal, and solar cycle variations of upper atmospheric parameter distributions. Two types of neural network architectures, feedforward and Elman recurrent, are used in this study. Topics discussed include the network design, training strategy, data analysis, as well as preliminary testing results of the networks on electron concentration distributions
Disability in Ohio : Current and Future Demand for Services
Get PDFIn an effort to project the size of Ohio s Medicaid long-term care expenditures between now and the year 2020, this report first projected the size of the population with severe physical and/or cognitive, intellectual and/or developmental, and mental illness disabilities. Then, assuming different rates of medical and long-term care inflations the author projected both the total Medicaid and Medicaid long-term care expenditures