Managing the US Navy's first OO digital mapping project

In the late 1980s the Defense Mapping Agency began converting their paper maps into digital format. A military standard known as Vector Product Format emerged as the format for storing digital vector data. The VPF relational data model, however, has problems representing complex spatial data. In 1991, the US Navy, a DMA database user, began investigating how object technology could improve its digital maps. This research led to the development of the Object Vector Product Format, an object-oriented approach to viewing and editing digital maps and charts. By combining multiple relational databases into a single OO database, OVPF offers users such key advantages as the ability to immediately update and modify the content of the original data. Over the course of developing OVPF we have also learned some valuable lessons about managing OO projects. Our experiences have given us insight into some important risk-management techniques, including how to manage the expectations of decision-makers and sponsors and how to implement effective training methods. Managing the OVPF project was much more rewarding than most due to the greatly increased productivity offered by an OO approach     

T-cell activation: interplay at the interface

Recent studies have shown that, when a T cell interacts with a cognate antigen-presenting cell, an organized adhesive contact is formed between the two cells by a process which involves the dynamic, three-dimensional redistribution of entire signaling assemblies.     

The Construction of Beauty: A Cross-Cultural Analysis of Women's Magazine Advertising

As a media genre, advertising offers a unique opportunity to study how the beauty ideal is constructed across cultures. This research analyzes the content of advertisements from women's fashion and beauty magazines in Singapore, Taiwan, and the U.S. to compare how beauty is encoded and found a noticeable difference between the portrayals of women from the U.S. and from the two East Asian societies in terms of sexual portrayal. In addition, Asian ads contained a large proportion of cosmetics and facial beauty products whereas the U.S. ads were dominated by clothing. These findings suggest that beauty in the U.S. may be constructed more in terms of "the body," whereas in Singapore and Taiwan the defining factor is more related to a pretty face. The article also discusses how feminist critiques of the sexual objectification of women in advertising may need to be considered within their historical, Western context of origin.     

Failure mode and effects analysis in the U.K. motor industry: A state-of-the-art study

This paper reports the main findings of a questionnaire survey on the use of failure mode and effects analysis (FMEA) in the United Kingdom motor industry. Survey data were obtained from 78 organizations. Among the main findings are: the majority of suppliers only started to use FMEA because it was a contractual requirement of their customer; however, a number of them are now seeking to make more use of the technique to facilitate their process of quality improvement; FMEA is treated by the majority of organizations as a team activity; engineers still view FMEA as a hard slog; more use should be made of computerized aids to reduce the effort in preparing and updating the FMEA; and the main difficulties encountered in the use of FMEA are related to time constraints, poor organizational understanding of the importance of FMEA, inadequate training and lack of management commitment. It is also pointed out that organizations are not satisfied with the current training courses on FMEA.     

Improved Near-Infrared Spectral Responsivity Scale

A cryogenic radiometer-based system was constructed at the National Institute of Standards and Technology for absolute radiometric measurements to improve detector spectral power responsivity scales in the wavelength range from 900 nm to 1800 nm. In addition to the liquid-helium-cooled cryogenic radiometer, the system consists of a 100 W quartz-tungsten-halogen lamp light source and a 1 m single-grating monochromator for wavelength selection. The system was characterized and the uncertainty in spectral power responsivity measurements evaluated. A variety of photodetectors, including indium gallium arsenide photodiodes (InGaAs), germanium (Ge) photodiodes, and pyroelectric detectors, were subsequently calibrated. Over most of the spectral range, the spectral power responsivity of the photodetectors can be measured with a combined relative standard uncertainty of 0.4 % or less. This is more than a factor of two smaller than our previous capabilities, and represents a significant improvement in the near infrared (NIR) spectral power responsivity scale maintained at NIST. We discuss the characterization of the monochromator-based system and present results of photodetector spectral power responsivity calibrations.     

Dynamic stability in bipedal motion: Adaptive control strategies for balance and controlled motion

The exploration of dynamic stability in bidedal machines requires a great deal of knowledge about the science of balancing, both equilibrium and motion. Recent work in robotic legged locomotion has concentrated on systems that require three or more legs on the ground at any given time. This research focuses on adaptive control strategies for a bipedal machine that will allow balance and controlled motion with one leg and, if not walking, on two legs on the ground at any given time. Our approach is to optimize a set of balance and motion profiles through extensive simulation and to validate the profiles on an experimental testbed. Once validated as capable of providing dynamic stability, the adaptive control model uses these profiles as nominal control. The sensory input is then used to modify the nominal control to allow precise control at each sampling period. Simply stated, our control model continuously measures the rate of fall of the biped, and adjusts torques at the knees and hips to constrain this fall to dynamic balance and controlled motion. As should be suspected at this time, our control model is sensor driven and does not require a solution to the Lagrangian equations of motion. The result is a faster, less complex, adaptive control process. Our experimental bipedal testbed currently, and repeatedly, exhibits 25 + stable steps on a flat but slightly varied terrain. Current technology could not provide the kind of actuation and measurements necessary to implement our control model; therefore, our team has developed new low pressure, servoed hydraulic systems and sensory devices. Our most recent experimentation has used parallel computing methods and devices in the C + + programming language on a transputer (parallel computer) based Cogent XTM parallel computing workstation.

A new dimension to our research is the translation of our knowledge to manufacturing systems and machines. We are currently investigating how our knowledge of limb coordination and reflex can be applied to the coordination of multiple jointed appendages. In addition, we will explore the use of our positioning and balancing technology in the work cell.     

Fault equivalence in PLAs and prevention design

The fault equivalent problem in PLAs is examined and some design rules to solve this problem are proposed. The hardware required is only one extra product line, one bit line and one output line for the worst case.<>     

Earthquake-induced net section fracture in brace connections — experiments and simulations

Results from six tests, finite element simulations and a synthesis of previous test programs on slotted end bracing connections are presented. The main objective of the research is to examine the deformation capacity of these connections, with the ultimate objective of minimizing the requirement for net section reinforcement that is often inconvenient from the perspective of fabrication. The experiments and simulations feature commonly used pipe specimens and end details. The main parameters investigated include the gusset plate thickness, the slot length and introduction of a wrap-around weld that eliminates the reduced section at the edge of the gusset plate. The results indicate that even without reinforcement, the connections offer adequate to excellent deformation capacity if they are provided with the wrap-around weld or if the net section strength is larger than the gross yield strength. This may be achieved in situations where shear lag in the connection is minimal, and where the area reduction due to the slot is small relative to the gross area. Design considerations are presented along with limitations of the study.