Directional organization of eye movement and visual signals in the floccular lobe of the monkey cerebellum

The floccular lobe of the monkey is critical for the generation of visually-guided smooth eye movements. The present experiments reveal physiological correlates of the directional organization in the primate floccular lobe by examining the selectivity for direction of eye motion and visual stimulation in the firing of individual Purkinje cells (PCs) and mossy fibers. During tracking of sinusoidal target motion along different axes in the frontoparallel plane, PCs fell into two classes based on the axis that caused the largest modulation of simple-spike firing rate. For "horizontal" PCs, the response was maximal during horizontal eye movements, with increases in firing rate during pursuit toward the side of recording (ipsiversive). For "vertical" PCs, the response was maximal during eye movement along an axis just off pure vertical, with increases in firing rate during pursuit directed downward and slightly contraversive. During pursuit of target motion at constant velocity, PCs again fell into horizontal and vertical classes that matched the results from sinusoidal tracking. In addition, the directional tuning of the sustained "eye velocity" and transient "visual" components of the neural responses obtained during constant velocity tracking were very similar. PCs displayed very broad tuning approximating a cosine tuning curve; the mean half-maximum bandwidth of their tuning curves was 170-180 degrees. Other cerebellar elements, related purely to eye movement and presumed to be mossy fibers, exhibited tuning approximately 40 degrees narrower than PCs and had best directions that clustered around the four cardinal directions. Our data indicate that the motion signals encoded by PCs in the monkey floccular lobe are segregated into channels that are consistent with a coordinate system defined by the vestibular apparatus and eye muscles. The differences between the tuning properties exhibited by PCs compared with mossy fibers indicate that a spatial transformation occurs within the floccular lobe.     

Adaptive triangular-mesh reconstruction by mean-curvature-based refinement from point clouds using a moving parabolic approximation

We use a moving parabolic approximation (MPA) to reconstruct a triangular mesh that approximates the underlying surface of a point cloud from closed objects. First, an efficient strategy is presented for constructing a hierarchical grid with adaptive resolution and generating an initial mesh from point clouds. By implementing the MPA algorithm, we can estimate the differential quantities of the underlying surface, and subsequently, we can obtain the local quadratic approximants of the squared distance function for any point in the vicinity of the target shape. Thus, second, we adapt the mesh to the target shape by an optimization procedure that minimizes a quadratic function at each step. With the objective of determining the geometrical features of the target surface, we refine the approximating mesh selectively for the non-flat regions by comparing the estimated curvature from the point clouds and the estimated curvatures computed from the current mesh. Finally, we present various examples that demonstrate the robustness of our method and show that the resulting reconstructions preserve geometric details.     

A new vertical‐alignment LC mode with high‐transmittance and fast‐response‐time features

Abstract— A novel pixel design for vertical‐alignment LCDs with superior transmittance has been developed. The new liquid‐crystal mode, refered to as the hole‐induced vertical‐alignment mode (Hi‐VA), uses a via hole of an organic layer on a TFT substrate to achieve multi‐domain alignment. Compared to the conventional design, the Hi‐VA mode has a transmittance of up to 135% with a contrast ratio of 2000:1. Moreover, the new structure is free from ITO patterning or protrusion on the color‐filter side, which makes the fabrication process simple and low cost.     

Color juxtaposition for pointillism based on an artistic color model and a statistical analysis

We analyze characteristics and patterns of color juxtaposition and the color theory used by pointillist painters and employ them to create rendering algorithm that generates images in a pointillist style. We determine the distribution of colors in several paintings by Seurat and quantify a number of the theory that he employs. Using an RYB color wheel and a hierarchical point generation technique, we convert an input image into a set of colored dots, which is again converted into brush strokes with appropriate shapes and directions. We present images which illustrate the extent to which we have managed to simulate Seurat’s technique.     

CPG-based control of a turtle-like underwater vehicle

This paper presents biologically inspired control strategies for an autonomous underwater vehicle (AUV) propelled by flapping fins that resemble the paddle-like forelimbs of a sea turtle. Our proposed framework exploits limit cycle oscillators and diffusive couplings, thereby constructing coupled nonlinear oscillators, similar to the central pattern generators (CPGs) in animal spinal cords. This paper first presents rigorous stability analyses and experimental results of CPG-based control methods with and without actuator feedback to the CPG. In these methods, the CPG module generates synchronized oscillation patterns, which are sent to position-servoed flapping fin actuators as a reference input. In order to overcome the limitation of the open-loop CPG that the synchronization is occurring only between the reference signals, this paper introduces a new single-layered CPG method, where the CPG and the physical layers are combined as a single layer, to ensure the synchronization of the physical actuators in the presence of external disturbances. The key idea is to replace nonlinear oscillators in the conventional CPG models with physical actuators that oscillate due to nonlinear state feedback of the actuator states. Using contraction theory, a relatively new nonlinear stability tool, we show that coupled nonlinear oscillators globally synchronize to a specific pattern that can be stereotyped by an outer-loop controller. Results of experimentation with a turtle-like AUV show the feasibility of the proposed control laws.     

Integral floating‐image display using two lenses with reduced distortion and enhanced depth

Abstract— An integral floating display (IFD) with a long depth range without floating lens distortion is proposed. Two lenses were used to reduce barrel distortion of the floating lens and three‐dimensional (3‐D) image deformation from object‐dependent longitudinal and lateral magnifications in the floating‐display system, combined with an integral imaging display. The distance between the floating lenses is the sum of their focal lengths. In the proposed configuration, lateral and longitudinal magnifications are constant regardless of the distance of the integrated 3‐D images, so the distortions from the distant‐dependent magnifications of the floating lens do not occur with the proposed method. In addition, the proposed floating system expands the depth range of the integral imaging display. As a result, the display can show a correct 3‐D floating image with a large depth range. Experimental results demonstrate that the proposed method successfully displays a 3‐D image without floating lens distortions across a large depth range.     

ManiWordle: providing flexible control over Wordle

Among the multifarious tag-clouding techniques, Wordle stands out to the community by providing an aesthetic layout, eliciting the emergence of the participatory culture and usage of tag-clouding in the artistic creations. In this paper, we introduce ManiWordle, a Wordle-based visualization tool that revamps interactions with the layout by supporting custom manipulations. ManiWordle allows people to manipulate typography, color, and composition not only for the layout as a whole, but also for the individual words, enabling them to have better control over the layout result. We first describe our design rationale along with the interaction techniques for tweaking the layout. We then present the results both from the preliminary usability study and from the comparative study between ManiWordle and Wordle. The results suggest that ManiWordle provides higher user satisfaction and an efficient method of creating the desired "art work," harnessing the power behind the ever-increasing popularity of Wordle.     

Seat inventory control for sequential multiple flights with customer choice behavior

This paper considers a seat inventory control problem in which flights depart sequentially and passengers purchase available seats depending on customer choice behavior. Customer choice behavior can lead to either a horizontal shift or a booking loss when a desired fare class is unavailable. This problem is mathematically challenging and intractable via exact mathematical models. As an alternative heuristic approach, this paper develops a simulation-based greedy grid-search algorithm and illustrates simulation experiments using the newly developed algorithm. This paper obtains encouraging numerical results with the approach proposed here, but additional studies are required for accommodating more general assumptions such as booking arrival patterns, booking control mechanisms (e.g., cancellation and overbooking) and strategic customer behavior.     

A fact-oriented ontological approach to human process modeling for knowledge-intensive business services

Modern business environment emphasizes the role of knowledge-intensive business services (KIBS). As well as the enterprises in any other kinds of industries, business process management (BPM) can be a source of core competency for the enterprises in KIBS industry. However, most of the business processes in KIBS are human processes which are collaborative, innovative, and dynamic, which cannot be supported well by current BPM technologies. Human interaction management (HIM) has emerged as an alternative theory to deal with human processes in KIBS. But, the current ways of process modeling and management in HIM have a problem of complexity, especially in terms of realizing its principle of ‘supportive activity management’. This research adopts fact-oriented ontological approach to address this problem. Based on fact-oriented approach, human-friendly condition modeling and state management during supportive activity management can be achieved.     

Catching two rabbits: adaptive real‐time support for embedded Linux

The trend of digital convergence makes multitasking common in many digital electronic products. Some applications in those systems have inherent real‐time properties, while many others have few or no timeliness requirements. Therefore the embedded Linux kernels, which are widely used in those devices, provide real‐time features in many forms. However, providing real‐time scheduling usually induces throughput degradation in heavy multitasking due to the increased context switches. Usually the throughput degradation becomes a critical problem, since the performance of the embedded processors is generally limited for cost, design and energy efficiency reasons. This paper proposes schemes to lessen the throughput degradation, which is from real‐time scheduling, by suppressing unnecessary context switches and applying real‐time scheduling mechanisms only when it is necessary. Also the suggested schemes enable the complete priority inheritance protocol to prevent the well‐known priority inversion problem. We evaluated the effectiveness of our approach with open‐source benchmarks. By using the suggested schemes, the throughput is improved while the scheduling latency is kept same or better in comparison with the existing approaches. Copyright © 2008 John Wiley & Sons, Ltd.