Instance-based prediction of real-valued attributes

Instance-based representations have been applied to numerous classification tasks with a fair amount of success. These tasks predict a symbolic class based on observed attributes. This paper presents a method for predicting a numeric value based on observed attributes. We prove that if the numeric values are generated by continuous functions with bounded slope, then the predicted values are accurate approximations of the actual values. We demonstrate the utility of this approach by comparing it with standard approaches for value-prediction. The approach requires no background knowledge

Detecting and removing noisy instances from concept descriptions

Several published results show that instance-based learning algorithms record high classification accuracies and low storage requirements when applied to supervised learning tasks. However, these learning algorithms are highly sensitive to training set noise. This paper describes a simple extension of instance-based learning algorithms for detecting and removing noisy instances from concept descriptions. The extension requires evidence that saved instances be significantly good classifiers before it allows them to be used for subsequent classification tasks. We show that this extension's performance degrades more slowly in the presence of noise, improves classification accuracies, and further reduces storage requirements in several artificial and real-world databases

Comparing instance-averaging with instance-saving learning algorithms

The goal of our research is to understand the power and appropriateness of instance-based representations and their associated acquisition methods. This paper concerns two methods for reducing storage requirements for instance-based learning algorithms. The first method, termed instance-saving, represents concept descriptions by selecting and storing a representative subset of the given training instances. We provide an analysis for instance-saving techniques and specify one general class of concepts that instance-saving algorithms are capable of learning. The second method, termed instance-averaging, represents concept descriptions by averaging together some training instances while simply saving others. We describe why analyses for instance-averaging algorithms are difficult to produce. Our empirical results indicate that storage requirements for these two methods are roughly equivalent. We outline the assumptions of instance-averaging algorithms and describe how their violation might degrade performance. To mitigate the effects of non-convex concepts, a dynamic thresholding technique is introduced and applied in both the averaging and non-averaging learning algorithms. Thresholding increases the storage requirements but also increases the quality of the resulting concept descriptions

Episodic learning

A system is described which learns to compose sequences of operators into episodes for problem solving. The system incrementally learns when and why operators are applied. Episodes are segmented so that they are generalizable and reusable. The idea of augmenting the instance language with higher level concepts is introduced. The technique of perturbation is described for discovering the essential features for a rule with minimal teacher guidance. The approach is applied to the domain of solving simultaneous linear equations

A study of RSI under combined stresses

The behavior of typical rigidized surface insulation material (RSI) under combined loading states was investigated. In particular, the thermal stress states induced during reentry of the space shuttle were of prime concern. A typical RSI tile was analyzed for reentry thermal stresses under computed thermal gradients for a model of the RSI material. The results of the thermal stress analyses were then used to aid in defining typical combined stress states for the failure analysis of RSI

Archeological Survey For The West Borgfeld Drive Improvements From Timberline Drive To Blanco Road, Bexar County, Texas

On February 27, 2015, Prewitt and Associates, Inc. conducted an archeological survey for proposed improvements along West Borgfeld Drive from Timberline Drive to Blanco Road in Bexar County, Texas. The project will reconstruct West Borgfeld Drive from two lanes to four lanes. These improvements will take place within the existing 86-ft-wide right of way of West Borgfeld Drive and comprise a horizontal Area of Potential Effects (APE) of ca. 20 acres. The survey found that the existing right of way West Borgfeld Drive is disturbed by travel lanes, overhead and buried utility lines, previous land leveling or grading, and erosion, which has stripped much of the landscape of its soil mantle. No archeological sites or materials were encountered during the survey. Therefore, it is recommended that the project proceed without any further archeological work

Preliminary Cultural Resources Investigations for the Pharr-Reynosa International Bridge, Hidalgo County, Texas

Archeological, archival, and geomorphologic investigations were conducted for the proposed Pharr-Reynosa International Bridge Project in Hidalgo County, Texas, by Prewitt and Associates, Inc. from October 12-27, 1992. The purposes of these investigations were to locate and record any cultural resources within the project area, determine their eligibility for listing on the National Register of Historic Places and designation as State Archeological Landmarks, and to provide an overview of the Holocene geomorphic history of the project area. The geomorphic history of the project area suggests that the Rio Grande has experienced continuous channel aggradation from the end of the Pleistocene to ca. 1000 B.P. Climatic changes and diminishing sediment loads led to channel incision around 1000 B.P., forming a low late Holocene terrace and resulting in increased sinuosity and a decreased channel width-to-depth ratio. The investigations included a stratified sample survey of approximately 162 hectares (400 acres) and the excavation of 16 backhoe trenches and 14 shovel tests. A total of 10 sites, consisting of 10 historic and 2 prehistoric components, were documented. Six standing architectural properties, each consisting of a structure or groups of structures, also were documented. Four of the sites (41HG153, 41HG155, 41HG156, and 41HG158) are considered to be potentially eligible for listing on the National Register of Historic Places and for designation as State Archeological Landmarks. Two of the architectural properties - the Carmichael and Sorenson farmsteads - also may be eligible for listing on the National Register. The four potentially eligible sites consist of four historic and two prehistoric components. The historic components date from the Texas Republic period to the early twentieth century, representing the establishment and development of the EI Capote Ranch community. The two prehistoric components (41HG153 and 41HG158), of which only 41HG153 is potentially eligible, represent Late Prehistoric and unknown prehistoric components, respectively

Sixmile Creek Drainage Improvements, Project SA-43 Bexar County, Texas

On June 2–3, 2014, Prewitt and Associates, Inc., conducted an archeological survey for proposed drainage improvements along a ca. 2,800-foot (ft) (853 meter [m]) segment of the Sixmile Creek channel downstream from Roosevelt Avenue in San Antonio, Texas. Desktop research and an earlier field reconnaissance found that the Area of Potential Effects (APE) has little to no potential of yielding significant archeological resources based on the geologic and geomorphic setting and twentieth-century channel and landscape modifications. Based on these findings, the current investigations focused on two known cultural resources near the APE: the Stinson #1 cemetery (part of 41BX789) and the ca. 1925 Airport Captain’s House. The Stinson #1 cemetery is outside the APE. Investigations consisting of mechanical scraping and trenching in a search for unmarked graves focused on the area between the cemetery and the APE. No unmarked graves were found. The standing structures associated with the Airport Captain’s House, which consist of a house and garage, are outside the APE, but residential debris, most likely associated with the use of these structures, was observed scattered across the surface and intersecting the APE. The standing structures, along with the historic artifact scatter, were recorded as archeological site 41BX2010. As an archeological resource, it is recommended that 41BX2010 be judged ineligible for listing in the National Register of Historic Places (under Criterion D) or designation as a State Antiquities Landmark. The standing structures at the site, however, are eligible for listing in the National Register of Historic Places under Criterion A. Because of this, project-related impacts to the structures should be avoided, and a buffer zone of at least 30 meters (m) (100 ft) should be demarcated around the structures during project construction. By creating a buffer zone, no eligible cultural resources will be impacted, and it is recommended that the proposed project be allowed to proceed as planned. No artifacts requiring curation were collected during the survey

Archeological and Geomorphological Investigations at Prehistoric Sites 41WY50 and 41WY60, Willacy County, Texas

In January through March 1993, archeological and geomorphological investigations were conducted at two clay dune sites, 41WY50 and 41WY60, in the outfall area of the Hidalgo-Willacy Drainage Ditch system. This work represents the final investigations of a cultural resource management program conducted for the U.S. Army Corps of Engineers and the local sponsors, Hidalgo County Drainage District No. 1 and Willacy County Drainage District No. I, by Prewitt and Associates, Inc. The results of the archeological investigations were poor. Neither site yielded materials of unquestionable cultural origin, although several small basin-shaped hearth features were encountered. Based on radiocarbon assays from soil humates and the stratigraphic provenience of the features, it is speculated that the occupation(s) at 41WY50 is late Archaic and the occupation(s) at 41WY60 is Late Prehistoric to Historic. Both sites represent very short term occupations and most likely do not represent repetitive use on a seasonal or yearly basis. These investigations suggest that, since the development of the modem coastal environments approximately 3,000 to 4,000 years ago, the south Texas coast between Baffin Bay and the Holocene delta of the Rio Grande has been a resource-poor and inhospitable area that probably was utilized only sparsely or intermittently. The geomorphological investigations were more successful, adding valuable data ahout paleoenvironments and the formation of the modem coastal environments of the Lower Rio Grande Valley. The clay dunes formed through the eolian transport of fine to very fine quartz sand and fine to very fine sand-sized aggregates of clay from adjacent wind-tidal flats during the late Holocene. Stable carbon isotope studies of soil humates suggest that the clay dune plant community was and still is dominated by C, and/or CAM plants. These investigations also disclosed fluctuations in sea level during the late Holocene. An abandoned wind-tidal flat, encountered at 41WY50, indicates that sea level was at least I m higher than present mean sea level between 2300-1100 B.P

Bases for qudits from a nonstandard approach to SU(2)

Bases of finite-dimensional Hilbert spaces (in dimension d) of relevance for quantum information and quantum computation are constructed from angular momentum theory and su(2) Lie algebraic methods. We report on a formula for deriving in one step the (1+p)p qupits (i.e., qudits with d = p a prime integer) of a complete set of 1+p mutually unbiased bases in C^p. Repeated application of the formula can be used for generating mutually unbiased bases in C^d with d = p^e (e > or = 2) a power of a prime integer. A connection between mutually unbiased bases and the unitary group SU(d) is briefly discussed in the case d = p^e.Comment: From a talk presented at the 13th International Conference on Symmetry Methods in Physics (Dubna, Russia, 6-9 July 2009) organized in memory of Prof. Yurii Fedorovich Smirnov by the Bogoliubov Laboratory of Theoretical Physics of the JINR and the ICAS at Yerevan State University