Assessing Project Success Using Subjective Evaluation Factors

Project evaluation is essential to understand and assess the key aspects of a project that make it either a success or failure. The latter is influenced by a large number of factors, and many times it is hard to measure them objectively. This paper addresses this by introducing a new method for identifying and assessing key project characteristics, which are crucial for a project's success. The method consists of a number of well-defined steps, which are described in detail. The method is applied to two case studies from different application domains and continents. It is concluded that patterns are possible to detect from the data sets. Further, the analysis of the two data sets shows that the proposed method using subjective factors is useful, since it provides an increased understanding, insight and assessment of which project factors might affect project success.     

Ethical Issues in Empirical Software Engineering: The Limits of Policy

Empirical studies in software engineering can involve a variety of organizations, each with their own set of policies and procedures geared at safeguarding the interests and responsibilities of the researchers, students, the collaborating company, the university, and possibly national funding agencies like the National Science Foundation and the National Institute of Health. Each of these organizations have differing goals for participating in these studies and bring widely different cultures and expectations to the table. While policies, procedures, contracts, and agreements set expectations, they by themselves cannot ensure ethical behavior. This position paper describes some of the common approaches to encourage ethical behavior and their limits for enforcing ethical behavior.     

Communicating over nonstationary nonflat wireless channels

We develop the concept of joint time-frequency estimation of wireless channels. The motivation is to optimize channel usage by increasing the signal-to-noise ratio (SNR) after demodulation while keeping training overhead at a moderate level. This issue is important for single-input single-output (SISO) and multiple-input multiple-output (MIMO) systems but particularly so for the latter. Linear operators offer a general mathematical framework for symbol modulation in channels that vary both temporally and spectrally within the duration and bandwidth of one symbol. In particular, we present a channel model that assumes first-order temporal and spectral fluctuations within one symbol or symbol block. Discrete prolate spheroidal sequences (Slepian sequences) are used as pulse-shaping functions. The channel operator in the Slepian basis is almost tridiagonal, and the simple intersymbol interference pattern can be exploited for efficient and fast decoding using Viterbi's algorithm. To prove the concept, we use the acoustic channel as a meaningful physical analogy to the radio channel. In acoustic 2 /spl times/ 2 MIMO experiments, our method produced estimation results that are superior to first-order time-only, frequency-only, and zeroth-order models by 7.0, 9.4, and 11.6 db. In computer simulations of cellular wireless channels with realistic temporal and spectral fluctuations, time-frequency estimation gains us 12 to 18 db over constant-only estimation in terms of received SNR when signal-to-receiver-noise is 10 to 20 db. The bit error rate (BER) decreases by a factor of two for a binary constellation.     

On connections and higher-order logic

This is an expository introduction to an approach to theorem proving in higher-order logic based on establishing appropriate connections between subformulas of an expanded form of the theorem to be proved. Expansion trees and expansion proofs play key roles.This is an extended version of a lecture presented to the 8th International Conference on Automated Deduction in Oxford, England on 27 July 1986. This material is based upon work supported by the National Science Foundation under grants DCR-8402532 and CCR-8702699.     

Multiwall carbon nanotubes enhance the fatigue performance of physiologically maintained methyl methacrylate-styrene copolymer

The introduction of multiwall carbon nanotube (MWCNT)-polymer composites ushered in fresh opportunities for engineering new materials with high performance capabilities. The nanoscale dimensions and extraordinary properties of MWCNTs directly address the sub-micron damage mechanisms (such as crazing) that culminate during the fatigue failure of most polymers. The large traditional graphite fibers commonly used in composite materials do little to address these microscopic mechanisms of cyclic deformation; thus, MWCNTs offer new promise for improving the fatigue performance of polymer systems where the previous successes of traditional graphite fibers were limited. To test this theory, small amounts (0-10 wt%) of MWCNTs were added to methyl methacrylate-styrene copolymer (MMA-co-Sty), a chief component of commercial bone cement. The resulting nanocomposites were tested to failure in fully reversed tension-compression fatigue in a 37 °C saline environment. Testing at 20 MPa peak stress showed that adding 2 wt% and 5 wt% MWCNTs enhanced the fatigue performance of MMA-co-Sty by 565% and 592%, respectively. These results clearly demonstrate that MWCNTs can substantially enhance the fatigue performance of this polymer. Furthermore, a comparison of these results with the literature shows that MWCNTs are better candidates than traditional graphite fibers for improving the fatigue performance of polymer systems.     

Eliciting information about organizational culture via laddering

Abstract. Eliciting information about organizational culture is an important part of system analysis and design. However, eliciting knowledge of this sort is difficult. Laddering is an established technique that is particularly suitable for eliciting information about goals and for eliciting explanations, which are important issues when investigating organizational culture. This paper describes the method, its strengths and limitations, its use in several case studies and its relation to other elicitation techniques. Recommendations for further work are given.     

THE DEVELOPMENT OF ACID-RESISTING WHITE SHEET STEEL ENAMELS1

Many of the commercial sheet steel enamels are readily attacked by such weak acid solutions as fruit juices and are stained by milk and by some city waters. This paper gives the development of a number of acid-resisting enamels. It shows that acid resistance is the result of the right combinations of raw materials rather than the presence or absence of any particular constituent. Acid resistance is not affected by fineness of grinding or by the smelting conditions if the enamel is properly smelted. Mill additions of clay reduce the acid resistance but opacifiers added in this manner have no effect. Temperature and time of firing may or may not affect the acid resistance depending on the composition of the enamel.