A small‐area and low‐power data driver IC using two‐stage DAC with a capacitor array for active matrix flat‐panel displays

A small‐area and low‐power data driver integrated circuit (IC) using a two‐stage digital‐to‐analog converter (DAC) with a capacitor array is proposed for active matrix flat‐panel displays. The proposed data driver IC employs a capacitor array in the two‐stage DAC so as to reduce the DAC area and eliminate the need for a resistor string, which has high‐power consumption. To verify the proposed two‐stage DAC, a 20‐channel data driver IC with the proposed 10‐bit two‐stage DAC was fabricated using a 0.18‐μm complementary metal–oxide–semiconductor process with 1.8 and 6 V complementary metal–oxide–semiconductor devices. The proposed 10‐bit two‐stage DAC occupies only 43.8% of the area of a conventional 10‐bit two‐stage DAC. The measurement results show that the differential nonlinearity and integral nonlinearity are +0.58/?0.52 least significant bit and +0.62/?0.59 least significant bit, respectively. The measured interchannel deviation of the voltage outputs is 8.8 mV, and the measured power consumption of the 20‐channel data driver IC is reduced to 7.1 mW, which is less than half of the power consumed by the conventional one.     

An SNS-based model for finding collaborative partners

This paper proposes a model, Recommendation of Appropriate Partners (RAP), used on a Social Networking Service (SNS) for locating appropriate “helpers” for users based on individual users’ Chain of Friends (CoF) relationships. Using the RAP model, individual users can participate in a collaborative online community in remote locations, whereby helpers are willing to help other users solve their tasks/problems, and it is intended that both the users and helpers gain knowledge from these interactive online sessions. An example of the RAP-based system was implemented to invite Program Committee members to an international conference. The system was evaluated and the experimental results show that our model is very effective for discovering collaboration partners and finding users with similar interests in order to create communities for providing future and longer-term helping exchange.

     

Leader’s dilemma game: An experimental design for cyber insider threat research

One of the problems with insider threat research is the lack of a complete 360° view of an insider threat dataset due to inadequate experimental design. This has prevented us from modeling a computational system to protect against insider threat situations. This paper provides a contemporary methodological approach for using online games to simulate insider betrayal for predictive behavioral research. The Leader’s Dilemma Game simulates an insider betrayal scenario for analyzing organizational trust relationships, providing an opportunity to examine the trustworthiness of focal individuals, as measured by humans as sensors engaging in computer-mediated communication. This experimental design provides a window into trustworthiness attribution that can generate a rigorous and relevant behavioral dataset, and contributes to building a cyber laboratory that advances future insider threat study.     

Optimization of Geoscience Laser Altimeter System waveform metrics to support vegetation measurements

The Geoscience Laser Altimeter System (GLAS) has collected over 250 million measurements of vegetation height over forests globally. Accurate vegetation heights can be determined using waveform metrics that include vertical extent and extent of the waveform's trailing and leading edges. All three indices are highly dependent upon the signal strength, background noise and signal-to-noise ratio of the waveform, as the background noise contribution to the waveforms has to be removed before their calculation. Over the last six years, GLAS has collected data during thirteen observation periods using illumination from three different lasers. The power levels of these lasers have changed over time, resulting in variable signal power and noise characteristics. Atmospheric conditions vary continuously, also influencing signal power and noise.To minimize these effects, we optimized a noise coefficient which could be constant or vary according to observation period or noise metric. This parameter is used with the mean and standard deviation of the background noise to determine a noise level threshold that is removed from each waveform. An optimization analysis was used with a global dataset of waveforms that are near-coincident with waveforms from other observation periods; the goal of the optimization was to minimize the difference in vertical extent between spatially overlapping GLAS observations. Optimizations based on absolute difference in height led to situations in which the total extent was minimized as well; further optimizations reduced a normalized difference in height extent. The simplest optimizations were based on a constant value to be applied to all observations; noise coefficients of 2.7, 3.2, 3.4 and 4.0 were determined for datasets consisting of global forests, global vegetation, forest in the legal Amazon basin and boreal forests respectively. Optimizations based on the power level or the signal-to-noise ratio of waveforms best minimized differences in waveform extent, decreasing the percent root mean squared height difference by 25-54% over the constant value approach. Further development of methods to ensure temporal consistency of waveform indices will be necessary to support long-term satellite lidar missions and will result in more accurate and precise estimates of canopy height.     

Evolutionary driver scheduling with relief chains.

Public transport driver scheduling problems are well known to be NP-hard. Although some mathematically based methods are being used in the transport industry, there is room for improvement. A hybrid approach incorporating a genetic algorithm (GA) is presented. The role of the GA is to derive a small selection of good shifts to seed a greedy schedule construction heuristic. A group of shifts called a relief chain is identified and recorded. The relief chain is then inherited by the offspring and used by the GA for schedule construction. The new approach has been tested using real-life data sets, some of which represent very large problem instances. The results are generally better than those compiled by experienced schedulers and are comparable to solutions found by integer linear programming (ILP). In some cases, solutions were obtained when the ILP failed within practical computational limits.     

Robust Adaptive Control of Robots Using Neural Network: Global Stability

A desired compensation adaptive law‐based neural network (DCAL‐NN) controller is proposed for the robust position control of rigid‐link robots. The NN is used to approximate a highly nonlinear function. The controller can guarantee the global asymptotic stability of tracking errors and boundedness of NN weights. In addition, the NN weights here are tuned on‐line, with no offline learning phase required. When compared with standard adaptive robot controllers, we do not require linearity in the parameters, or lengthy and tedious preliminary analysis to determine a regression matrix. The controller can be regarded as a universal reusable controller because the same controller can be applied to any type of rigid robots without any modifications. A comparative simulation study with different robust and adaptive controllers is included.     

The Other Mathematical Bridge

This paper contextualises, describes and discusses a student project which takes a particular exploratory approach to using mathematical surface definition as a language and vehicle for co-rational design co-authorship for architecture and engineering. The project has two authors, one from an architectural and one from an engineering educational background. It investigates the metaphorical and operational role of mathematics in the design process and outcomes.     

Kinematics of heelstrike during walking and carrying: implications for slip resistance testing

Slip resistance measurements of shoes and floors are used to evaluate the potential for slip and fall injuries. These measurements are believed to have increased validity when they more closely reflect actual heelstrike biomechanics during locomotion. The purpose of this study was to describe heelstrike kinematics during load carrying to provide data towards improved slip resistance testing. Foot kinematics during load carrying (unladen and carrying from 0 to 13.5 kg) at various cadences (70, 90, 100 steps/min) was recorded. Measures before, during and after heelstrike were analysed. Cadence was an important predictor for all variables measured, associated with changes from 13% to over 100%. The load carried was an important predictor for only the heel slip distance after heelstrike, but this effect needs to be investigated further. These results can be used to improve the fidelity of slip resistance measurements, which is critical to reduce slip and fall injuries in the workplace or during activities of daily living.     

Large displays enhance optical flow cues and narrow the gender gap in 3-D virtual navigation

OBJECTIVE: Existing reports suggest that males significantly outperform females in navigating 3-D virtual environments. Although researchers have recognized that this may be attributable to males and females possessing different spatial abilities, most work has attempted to reduce the gender gap by providing more training for females. In this paper, we explore using large displays to narrow the gender gap within these tasks. BACKGROUND: While evaluating various interaction techniques, we found that large displays affording wider fields of view seemed to improve virtual navigation performance in general and, additionally, to narrow the gender gap that existed on standard desktop displays. METHOD: We conducted two experiments (32 and 22 participants) exploring the individual contributions of display and geometric fields of view to the observed effects as well as isolating factors explaining performance increases seen on the large displays. RESULTS: We show that wider fields of view on large displays not only increase performance of all users on average but also benefit females to such a degree as to allow them to perform as well as males do. We further demonstrate that these benefits can be attributed to better optical flow cues offered by the large displays. CONCLUSION: These findings provide a significant contribution, including recommendations for the improved presentation of 3-D environments, backed by empirical data demonstrating performance benefits during navigation tasks. APPLICATION. Results can be used to design systems that narrow the gender gap in domains such as teleoperation and virtual environments for entertainment, virtual training, or information visualization.