L-shaped Line Research Articles

Regulating, braking and pushing mechanisms of reindeer (Rangifer tarandus) feet based on center of pressure

Abstract Reindeer are seasonal migratory animals, and their feet play a significant role in braking and pushing. Their natural habitats in arctic regions require them to navigate complex ground conditions, and their feet have evolved to adapt to these challenges. Reindeer must travel long distances to find food and water, which demands high levels of endurance and stamina. The ability of reindeer feet to support their weights and maintain stability over extended periods is crucial to the survival of reindeer. The center of pressure at different speeds (walking, low-speed trotting, and high-speed trotting) was studied using a pressure plate to determine the functions of the dewclaws, medial toes and lateral toes of reindeer. The medial toes and lateral toes were the bearing toes, and the dewclaws played an auxiliary supporting role. The proportions of peak value in the bearing toes and dewclaws were 85.1-9.5% and 2.7-22.9%, respectively. The center-of-pressure trajectories of hindfeet and forefeet were an L-shaped line and a straight line, respectively. The proportion of peak value in forefoot dewclaws (7.0-22.9%) was larger than that of hindfoot dewclaws (2.7-8.2%). The coefficients of variation of forefoot dewclaws increased with rising speed, indicating the forefeet adjusted the pressure according to the motion state. The coefficient of variation of forefoot dewclaws (31.1-73.1%) was larger than that of bearing toes (14.1-40.7%), indicating the dewclaws played a stabilization role. The pressure on the bearing toes of the forefeet, which played a braking role, increased with time during the braking phase. The peak loads on the distal medial toe and the distal lateral toe of hindfeet were both in the pushing phase, which were mainly associated with a pushing role. Hence, the characteristics of reindeer feet are conducive to improving the stabilizing and migrating abilities.

Pattern Transfer Printing by Controlling the Deposition Angle to Form Various Patterns

The nanofabrication of modern electronic devices requires advanced nanopatterning technologies. To fabricate desirable nanodevices with excellent device performance, controlling the shape and dimension of the pattern is very important. However, to achieve more facile and faster device fabrication, with better pattern resolution, pattern-tunability, process simplicity, and cost-effectiveness, some remaining challenges still need to be resolved. In this study, we introduce a simple and practical method to generate various patterns using a nanotransfer printing (nTP) process. To obtain functional materials with diverse shapes on a polymer replica pattern, in the nTP process we controlled the angle of deposition before transfer-printing. First, we obtained three different pattern shapes with a thickness of ~ 30 nm on polymethyl methacrylate (PMMA) replica patterns. Then, the deposited functional patterns on the PMMA patterns are successfully transfer-printed onto SiO<sub>2</sub>/Si substrates, showing line, L-shape line, and concavo-convex patterns. We observed the pattern shapes of the patterns by scanning electron microscope (SEM) and optical microscope. Moreover, we systemically analyzed how to form patterns of various shapes using one kind of master mold. We expect that this simple approach will be widely used to fabricate various useful patterns for electronic device applications.

Fundamental study on the nanocryotron properties by the numerical calculation

We investigated the variation in current and temperature in the L-shaped line with the change in the injection current by the numerical calculation method, as the first step to study the electrical properties of the nanostructure devices. Nanostructure devices such as nanocryotron (nTron) are candidates for the interface device in the hybridization of superconducting single-flux-quantum circuits with semiconductor devices such as CMOS memories. However, physics of these nanostructure devices is not clear yet. Thus, we are investigating the behavior of the nanostructure devices by simulation using the time-dependent Ginzburg-Landau equation and the thermal diffusion equation. We have also been fabricating nanostructure devices and investigating their properties. The simulation in this report and its future progress will help to analyze and understand the experimental results, and will also provide device design guidelines.

Inverted L-shape line feed Quad-band Microstrip Antenna for Multiband Application

Inverted L-shape line feed Quad-band Microstrip Antenna for Multiband Application

A Simple Planar Heptaband Antenna with a Coupling Feed for 4G Mobile Applications

A simple planar heptaband antenna with a coupling feed for 4G mobile applications is proposed. This antenna consists of a folded monopole and a feed strip line on the top plane and an L-shaped line with a coupling plate on the bottom plane. The antenna provides a wide bandwidth to cover the LTE/GSM/UMTS heptaband operation. The measured 6-dB return loss bandwidth is 152 MHz (820?972 MHz) in the lowfrequency band and 1,150 MHz (1,600?2,750 MHz) in the high-frequency band. The overall dimensions of the proposed antenna are 60 mm × 105 mm × 1.2 mm.

A planar-printed E-shaped omnidirectional magneto-electric dipole antenna for WWAN/LTE applications

A planar-printed E-shaped dual-wideband magneto-electric (ME) dipole antenna for WWAN/LTE applications is proposed. Through changing the surface-current distributions, an E-shaped electric-dipole structure is used to provide a dual-wideband. Besides, to reduce the size of the antenna and improve impedance matching, a novel feeding structure designed with inverted U-shaped tapered line and meandering L-shaped line is introduced. Finally, without conventional vertical ground planes, a small-size one is printed on the back side of the substrate to attain stable gains and omnidirectional radiation patterns. The antenna prototype can attain a bandwidth of 31.6% (0.80–1.10 GHz) with a stable gain of 3.1 ± 0.5 dBi for the lower band, and a bandwidth of 47.5% (1.67–2.71 GHz) with a gain of 3.9 ± 0.7 dBi for the upper band, covering the frequency bands for WWAN/LTE systems. In comparison with the existing ME dipole antennas, the proposed antenna can be easily fabricated at low cost which makes it suitable for WWAN/LTE applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1734–1739, 2014

Formation of arbitrary patterns in ultraviolet cured polymer film via electrohydrodynamic patterning.

Electrohydrodynamic patterning of arbitrary patterns is achieved by optimizing the critical parameters (applied voltage and spacer height). The applied voltage has a great influence on the fidelity of L-shaped line structures with different sizes. The L-shaped line structures with high fidelity are obtained by using the moderate applied voltage. The spacer height has a great influence on the fidelity of square structures with different sizes. The square structures with high fidelity are obtained by using the low height spacer. The multi-field coupling transient finite element simulation demonstrates that the lack of polymer owing to the high height spacer leads to the formation of defects.

Flexible route selection by pigeons (Columba livia) on a computerized multi-goal navigation task with and without an “obstacle”.

The ability to select efficient routes while reaching several locations, in situations addressed as the "traveling salesperson problem (TSP)", seems to play an important role in the lives of nonhuman species as well as humans. One of our previous studies with pigeons (Columba livia) used different variations of computerized navigation tasks to move a target to one or more goals, and showed that the birds consistently exhibited tendencies to visit the nearest goal first (Miyata & Fujita, 2010). Is this inflexible tendency consistent across all situations, or is it abandoned if it leads to a nonefficient strategy? The present study compared pigeons' route selection strategies in two-goal navigation tasks with and without having an L-shaped line as an obstacle barrier between the starting location of the target and the nearer goal. The pigeons frequently started by visiting the nearer goal in trials with no obstacles, whereas in trials having obstacles the birds often visited the farther goal first. For the detour trials with obstacles, the birds started from visiting the farther goal significantly more often than chance, even though disparity between the two traveling sequences was relatively small. The data demonstrated a case in which a tendency to visit the nearest goal was flexibly abandoned when the route required a detour behavior. Detailed analyses of the movement paths further suggest that the pigeons made decisions to choose a farther goal during the initial few steps, although a past history of reinforcement to avoid the barrier might have guided the birds' behavior.

A Printed Wide-Slot Antenna With a Modified L-Shaped Microstrip Line for Wideband Applications

A printed wide-slot antenna for wideband applications is proposed and experimentally investigated in this communication. A modified L-shaped microstrip line is used to excite the square slot. It consists of a horizontal line, a square patch, and a vertical line. For comparison, a simple L-shaped feed structure with the same line width is used as a reference geometry. The reference antenna exhibits dual resonance (lower resonant frequency <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> , upper resonant frequency <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ). When the square patch is embedded in the middle of the L-shaped line, <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> decreases, <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> remains unchanged, and a new resonance mode is formed between <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . Moreover, if the size of the square patch is increased, an additional (fourth) resonance mode is formed above <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . Thus, the bandwidth of a slot antenna is easily enhanced. The measured results indicate that this structure possesses a wide impedance bandwidth of 118.4%, which is nearly three times that of the reference antenna. Also, a stable radiation pattern is observed inside the operating bandwidth. The gain variation is found to be less than 1.7 dB.

Planning in human children (Homo sapiens) assessed by maze problems on the touch screen.

The authors examined how human children perform on maze tasks on the touch screen and whether the children plan the solution of the mazes. In Experiment 1, the authors exposed children around 3 years of age to a maze having an L-shaped line as a barrier that can be solved by moving an illustration of a dog (the target) to that of a bone (the goal) with their fingers. The participants successfully solved the maze by taking efficient routes more frequently than chance, although the authors found no evidence that a preview of the maze before starting to solve the task facilitated their performance. In Experiment 2, using a plus-shaped maze, the authors found that 3- and 4-year-old children plan and adjust their moves while solving the maze, with 4-year-olds showing more advanced and higher-level planning than 3-year-olds. Similarity of these results to what the authors previously found in pigeons tested in the same tasks may suggest an analogy for planning capacity in the behavioral level across taxa and developmental stages.

Nonlinear dynamics of coupled charged rotators

A needle rotator system is constructed and investigated as a model system for coupled oscillators with nonlocal interaction. Needle rotators placed in a strong homogeneous electrical field rotate by repulsive or attractive force between the electrodes and charge on the rotators created by the discharge. The charge on the rotators is simultaneously the source of long-range interaction between the rotators. This paper describes the case where all rotators were placed an equal distance from each other on a horizontal line perpendicularly to the homogeneous field, and where the sense of the rotation were the same. The experimental results show entrainment, hysteresis, multistability, and chaos phenomena in the coupled dynamics of the rotator system. Simulation of the needle rotator carried out using a model regarding the shape of the rotator as a L-shaped line reproduced the global features of dynamics of the rotator system. The possibility is discussed of whether a system consisting of needle rotators presents a real system of a coupled oscillator system with nonlocal interaction.