We explore the effect of dimensionality on the nearest neighbor problem. We show that under a broad set of conditions (much broader than independent and identically distributed dimensions), as dimensionality increases, the distance to the nearest data point approaches the distance to the farthest data point. To provide a practical perspective, we present empirical results on both real and synthetic data sets that demonstrate that this effect can occur for as few as 10-15 dimensions. These results should not be interpreted to mean that high-dimensional indexing is never meaningful; we illustrate this point by identifying some high-dimensional workloads for which this effect does not occur. However, our results do emphasize that the methodology used almost universally in the database literature to evaluate high-dimensional indexing techniques is flawed, and should be modified. In particular, most such techniques proposed in the literature are not evaluated versus simple linear scan, and are evaluated over workloads for which nearest neighbor is not meaningful. Often, even the reported experiments, when analyzed carefully, show that linear scan would outperform the techniques being proposed on the workloads studied in high (10-15) dimensionality!.

When is nearest neighbor meaningful

In one embodiment, an apparatus comprises a user authenticator and a transponder. The transponder is permitted to emit a wireless signal representing information stored in the apparatus in response to a wireless interrogation signal after the user authenticator has authenticated the identity of the user. In another embodiment, an apparatus comprises, a memory, a user input, and a transponder. The memory stores at least first and second distinct codes. The user input permits a user to select any one of the at least first and second codes for transmission in response to a wireless interrogation signal. The transponder emits a wireless signal representing the selected one of the at least first and second codes in response to an interrogation signal. In yet another embodiment, a token that may be used to engage in a transaction at a point of sale comprises a substrate, a rewritable memory, and a reconfigurable display. The rewriteable memory is supported by the substrate and can be selectively configured to store information on the token that identifies an account that is to be used to engage in the transaction at the point of sale. The substrate and memory are configured and arranged such that the substrate can be selectively interfaced with an apparatus at the point of sale to permit the apparatus to read the contents of the memory. The reconfigurable display is also supported by the substrate and displays at least some of the information that is stored in the rewritable memory.

Portable electronic authorization system and method

Systems and methods are disclosed for monitoring data transmissions on a network and detecting compromised networks. The systems and methods monitor communications involving network hosts and analyze the communications in view of the business function of the hosts. In certain embodiments the analysis is performed by associating a set of rules of operation for the sessions, hosts, and/or environment, and analyzing data packet transmissions to ascertain violations of the rules.

Systems and methods for detecting a compromised network

Embodiments of the invention provide a method for detecting changes in behavior of authorized users of computer resources and reporting the detected changes to the relevant individuals. The method includes evaluating actions performed by each user against user behavioral models and business rules. As a result of the analysis, a subset of users may be identified and reported as having unusual or suspicious behavior. In response, the management may provide feedback indicating that the user behavior is due to the normal expected business needs or that the behavior warrants further review. The management feedback is available for use by machine learning algorithms to improve the analysis of user actions over time. Consequently, investigation of user actions regarding computer resources is facilitated and data loss is prevented more efficiently relative to the prior art approaches with only minimal disruption to the ongoing business processes.

Modeling user access to computer resources

A system and method are disclosed for providing access over a computer network to system documentation at an online central service facility. A user is required to enter identifying indicia prior to accessing the online central service facility, the facility having at least one documentation database containing product and/or service data therein. The identifying indicia can include a user identification and a password, for example, and are matched with user data stored in a user database in the online central service facility to authenticate the user before providing user access into a document management system. Also, the user is checked to further determine what particular product and/or service data the user is entitled to. Such particular product or service data is then delivered to the user.

Method and apparatus for limited online access to restricted documentation

A usage based pattern authenticator for monitoring and reporting on user usage patterns in an operating system using a set of security rules and user usage patterns. This computer system security tool authenticates users at the operating system level in multi-user operating systems. It supports system administrators in limiting the ability of unauthorized users to disrupt system operations using a neural network and set of rules to track usage patterns and flag suspicious activity on the system. The data collection mode collects and stores usage patterns of authenticated users. The training mode trains an artificial neural network and sets the interconnection weights of the network. The production mode monitors and reports on usage patterns, and optionally performs automatic responses when confronted with non-authenticated users.

Usage pattern based user authenticator

Research has shown that over 90% of all adults experience dental caries, and the early diagnosis of the carious lesion has become an important aspect of maintaining dental health. Advanced diagnostic and imaging devices can be used to identify tooth damage due to caries, compensating for the low sensitivity (high false negative) rate of visual and visual-tactile inspection by dentists. However, existing systems have such a high false positive rate that dentists often do not rely on the results, instead relying on traditional visual or visual-tactile inspection. Of the existing computer-aided diagnostic systems, few if any use digital image analysis for detection and diagnosis. By using digital images and a graphical user interface, our system will give both quantitative and qualitative feedback to dental practitioners, which will address the weaknesses of existing systems. This paper details our proposed system that makes use of commercial imaging equipment commonly owned by dental practices, including an intraoral camera, to process the digital images of teeth and quantitatively assess the presence and extent of caries on the surface of teeth. We demonstrate the feasibility of using advanced image processing techniques and a C4.5 decision tree classifier to accurately identify caries from digital images.

An image-processing enabled dental caries detection system

Most parallel computations require the exchange of data between processing elements. One of important basic communication operations is all-reduce, a variation of the reduction operation. This paper presents an all-reduce communication operation scheme using all-to-all broadcast communication pattern. All-to-all broadcast is the operation in which each processor sends its message to all other processors, and receives messages from all other processors in the system. In this paper, we develop an efficient all-reduce operation scheme in a star network topology with the single-port communication capability. Communication time is compared against known broadcasting schemes to verify the efficiency of the suggested scheme.

/pdf/an-all-reduce-operation-in-star-networks-using-all-to-all-d95iluempq.pdf

An all-reduce operation in star networks using all-to-all broadcast communication pattern

Over 80% of dentists report having some type of back, neck or shoulder pain. Research has identified significant costs linked to a very high rate of Work-Related Musculoskeletal Disorders (WMSDs) associated with poor ergonomic positioning in dentists. The annual costs of WMSDs across all occupations are estimated to be between 13 and 54 billion dollars. Little research has been done to explore the design of portable, inexpensive, non-invasive and unobtrusive real-time systems to measure posture. This paper details the design and testing of our proposed system that applies signal processing and robust machine learning techniques to improve the ergonomics of dental practitioners. We outline a number of different signal processing and classification techniques tested and analytically compared with our proposed system. Our system makes use of commercial inclinometers embedded into a standard laboratory coat. The ability of the system to measure posture accurately in practical settings, without needing exact and obtrusive placement of sensors or extensive calibration, is demonstrated through a set of experiments with human subjects.

Signal processing and machine learning for real-time classification of ergonomic posture with unobtrusive on-body sensors; application in dental practice

/pdf/smart-lab-coat-for-the-smart-lab-coat-for-the-dental-4lk54vthjx.pdf

David Primeaux

Papers

Usage pattern based user authenticator

An image-processing enabled dental caries detection system

An all-reduce operation in star networks using all-to-all broadcast communication pattern

Signal processing and machine learning for real-time classification of ergonomic posture with unobtrusive on-body sensors; application in dental practice

Smart Lab Coat for the Smart Lab Coat for the Dental Practitioner Dental Practitioner