Category Learning in Rhesus Monkeys: A Study of the Shepard, Hovland, and Jenkins (1961) Tasks.

In influential research, R. N. Shepard, C. I. Hovland, and H. M. Jenkins (1961) surveyed humans' categorization abilities using tasks based in rules, exclusive-or (XOR) relations, and exemplar memorization. Humans' performance was poorly predicted by cue-conditioning or stimulus-generalization theories, causing Shepard et al. to describe it in terms of hypothesis selection and rule application that were possibly supported by verbal mediation. The authors of the current article surveyed monkeys' categorization abilities similarly. Monkeys, like humans, found category tasks with a single relevant dimension the easiest and perceptually chaotic tasks requiring exemplar memorization the most difficult. Monkeys, unlike humans, found tasks based in XOR relations very difficult. The authors discuss the character and basis of the species difference in categorization and consider whether monkeys are the generalization-based cognitive system that humans are not. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Can computers carry content ‘inexplicitly’?

I examine whether it is possible for content relevant to a computer's behavior to be carried without an explicit internal representation. I consider three approaches. First, an example of a chess playing computer carrying emergent content is offered from Dennett. Next I examine Cummins response to this example. Cummins says Dennett's computer executes a rule which is inexplicitly represented. Cummins describes a process wherein a computer interprets explicit rules in its program, implements them to form a chess-playing device, then this device executes the rules in a way that exhibits them inexplicitly. Though this approach is intriguing, I argue that the chess-playing device cannot exist as imagined. The processes of interpretation and implementation produce explicit representations of the content claimed to be inexplicit. Finally, the Chinese Room argument is examined and shown not to save the notion of inexplicit information. This means the strategy of attributing inexplicit content to a computer which is executing a rule, fails.I wish to thank Fred Dretske, JOhn Perry, and an anonymous reviewer for helpful comments and suggestions. Earlier versions of this paper were read at the American Philosophical Association Pacific Division Meeting in San Francisco in March, 1993, and at the 7th International Conference on Computing and Philosophy in Orlando in August, 1992.     

DEPP functionally graded piezoceramics via micro-fabrication by co-extrusion

This paper introduces the Dual Electro/Piezo Property (DEPP) gradient technique via Micro-Fabrication through Co-eXtrusion (MFCX) which pairs a high displacement lead zirconate titanate (PZT) piezoceramic with a high permittivity barium titanate (BT) dielectric. By grading with this material combination spatially across an actuator, the electric field is concentrated in the more active region for improved efficiency, higher displacements, and complex motions. To aid in synthesis and analysis of any gradient profile, compositional maps are provided for key material properties (density, stiffness, permittivity, and piezoelectric coefficients). The DEPP technique was validated, independent of the MFCX process, by powder pressing a conventional bimodal gradient beam which demonstrated through experiments high displacement capabilities at lower driving potentials than comparable functionally graded piezoceramic actuators. For more complex gradients, the MFCX process was adapted to the DEPP gradient technique and illustrated by the fabrication of a linearly graded prototype whose monolithic nature and gradual material variation significantly reduces internal stresses, improves reliability, and extends service lifetime.     

Exciton storage by Mn(2+) in colloidal Mn(2+)-doped CdSe quantum dots

Colloidal Mn (2+)-doped CdSe quantum dots showing long excitonic photoluminescence decay times of up to tau exc = 15 mus at temperatures over 100 K are described. These decay times exceed those of undoped CdSe quantum dots by approximately 10 (3) and are shown to arise from the creation of excitons by back energy transfer from excited Mn (2+) dopant ions. A kinetic model describing thermal equilibrium between Mn (2+ 4)T 1 and CdSe excitonic excited states reproduces the experimental observations and reveals that, for some quantum dots, excitons can emit with near unity probability despite being approximately 100 meV above the Mn (2+ 4)T 1 state. The effect of Mn (2+) doping on CdSe quantum dot luminescence at high temperatures is thus completely opposite from that at low temperatures described previously.     

A simulation based supply partner selection decision support tool for service provision in Dell

Partner selection is an important aspect of all outsourcing processes. Traditional partner selection typically involves steps to determine the criteria for outsourcing, followed by a qualification of potential suppliers and concluding with a final selection of partner(s). Reverse auctions (RAs) have widely been used for partner selection in recent times. However, RAs, although proven successful in initial price reduction strategies for product and service provision, can suffer from reduced effectiveness as the number of executions increases.This paper illustrates Dell’s experience of such diminishing returns for its outsourced after sales product repair service and presents the development of a new partner selection methodology, which incorporates a new process improvement stage to be executed in combination with the final selection phase. This new methodology is underpinned by the development of a computer based simulation supply partner selection decision support tool for service provision. The paper highlights the significant additional cost saving benefits and improvement in service achievable through the use of advanced simulation based decision supports.     

The illusion of requirements in software development

This viewpoint explores the possibility that many software development projects may have no useful requirements. Specifically, for problems (e.g., knowledge worker burnout) with two completely different solutions (e.g., better tool support or hire more employees), an analyst may state a goal (e.g., decrease work hours) but more specific desiderata are contingent on the chosen solution. Furthermore, without fully exploring the design space, the designer cannot be sure whether there exists another approach, which would achieve the goal without any commonality with known approaches. In these situations of sparse requirements, analysts may misrepresent design decisions as requirements, creating an illusion of requirements in software development.