Numerical Modeling of a Planing Hull Maneuvering in Full Scale Trail

2015 ◽  
Author(s):  
Ray-Qing Lin ◽  
Susan Brewton ◽  
George S. Hazen ◽  
Damien Bretall
Keyword(s):  
High Speed ◽  
High Performance ◽  
Dynamic Balance ◽  
High Capacity ◽  
Ship Motion ◽  
Motion Model ◽  
Planing Craft ◽  
Wide Range ◽  
Target Track ◽  
Flexible Tubes

The high-speed Rigid Hulled Inflatable Boat (RHIB) is one of the key forms of transportation for the U.S. Navy in littoral regions. This planing craft, shown in Figure 1, is a lightweight, high-performance, high-capacity boat. It is constructed with a solid, shaped hull and flexible tubes at the gunwale. The flexible tubes maintain a high buoyancy to avoid capsize in bad seas and to better absorb heavy loads. When the RHIB maneuvers in a seas state greater than 2, however, it often gets off plane or jumps to an entirely different heading regardless of the craft speed and heading relative to the direction of wave propagation. This behavior may cause the planing boat to miss its target track and veer off course. Furthermore, if a RHIB is supporting shore facilities or large ships transporting troops, the deviations and jumps may also impact the safety of the troops. In order to shine a light on improving the RHIB planing craft design for better performance at higher sea states, this study used a fully-nonlinear ship motion model named the Digital Self consistent Ship Experimental Laboratory (DiSSEL) by Lin and Kuang (2011a and 2011b) as a numerical tool to examine the dynamic balance of a six-degree-freedom (6DOF) RHIB. First the RHIB is maneuvered in Seas State 2, then in Seas State 3. The results of the simulation serve to better understand the underlying physics that cause dynamics instability at higher sea states. This study also serves to validate the accuracy of the DiSSEL ship motion model with observational data of a 10-meter long RHIB at Seas State 2. The model shows good agreement with experimental data in all headings and with a wide range of boat speeds (up to Froude number of 1.265).

scholarly journals Towards a Glass New World: The Role of Ion-Exchange in Modern Technology

2021 ◽  
Vol 11 (10) ◽  
pp. 4610
Author(s):  
Simone Berneschi ◽  
Giancarlo C. Righini ◽  
Stefano Pelli
Keyword(s):  
Ion Exchange ◽  
Communication Networks ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Modern Technology ◽  
Historical Background ◽  
Wide Range ◽  
Happy Marriage

Glasses, in their different forms and compositions, have special properties that are not found in other materials. The combination of transparency and hardness at room temperature, combined with a suitable mechanical strength and excellent chemical durability, makes this material indispensable for many applications in different technological fields (as, for instance, the optical fibres which constitute the physical carrier for high-speed communication networks as well as the transducer for a wide range of high-performance sensors). For its part, ion-exchange from molten salts is a well-established, low-cost technology capable of modifying the chemical-physical properties of glass. The synergy between ion-exchange and glass has always been a happy marriage, from its ancient historical background for the realisation of wonderful artefacts, to the discovery of novel and fascinating solutions for modern technology (e.g., integrated optics). Getting inspiration from some hot topics related to the application context of this technique, the goal of this critical review is to show how ion-exchange in glass, far from being an obsolete process, can still have an important impact in everyday life, both at a merely commercial level as well as at that of frontier research.

scholarly journals Plasmonic semiconductor nanogroove array enhanced broad spectral band millimetre and terahertz wave detection

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Jinchao Tong ◽  
Fei Suo ◽  
Tianning Zhang ◽  
Zhiming Huang ◽  
Junhao Chu ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
High Performance ◽  
Room Temperature ◽  
Spectral Band ◽  
High Capacity ◽  
Terahertz Wave ◽  
Semiconductor Surface ◽  
Wide Range ◽  
Low Sensitivity ◽  
Air Interfaces

AbstractHigh-performance uncooled millimetre and terahertz wave detectors are required as a building block for a wide range of applications. The state-of-the-art technologies, however, are plagued by low sensitivity, narrow spectral bandwidth, and complicated architecture. Here, we report semiconductor surface plasmon enhanced high-performance broadband millimetre and terahertz wave detectors which are based on nanogroove InSb array epitaxially grown on GaAs substrate for room temperature operation. By making a nanogroove array in the grown InSb layer, strong millimetre and terahertz wave surface plasmon polaritons can be generated at the InSb–air interfaces, which results in significant improvement in detecting performance. A noise equivalent power (NEP) of 2.2 × 10−14 W Hz−1/2 or a detectivity (D*) of 2.7 × 1012 cm Hz1/2 W−1 at 1.75 mm (0.171 THz) is achieved at room temperature. By lowering the temperature to the thermoelectric cooling available 200 K, the corresponding NEP and D* of the nanogroove device can be improved to 3.8 × 10−15 W Hz−1/2 and 1.6 × 1013 cm Hz1/2 W−1, respectively. In addition, such a single device can perform broad spectral band detection from 0.9 mm (0.330 THz) to 9.4 mm (0.032 THz). Fast responses of 3.5 µs and 780 ns are achieved at room temperature and 200 K, respectively. Such high-performance millimetre and terahertz wave photodetectors are useful for wide applications such as high capacity communications, walk-through security, biological diagnosis, spectroscopy, and remote sensing. In addition, the integration of plasmonic semiconductor nanostructures paves a way for realizing high performance and multifunctional long-wavelength optoelectrical devices.

scholarly journals Prototype Design and Experimental Evaluation of Autonomous Collaborative Communication System for Emerging Maritime Use Cases

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3871
Author(s):  
Jiri Pokorny ◽  
Khanh Ma ◽  
Salwa Saafi ◽  
Jakub Frolka ◽  
Jose Villa ◽  
...  
Keyword(s):  
Communication System ◽  
Autonomous Vehicles ◽  
High Speed ◽  
High Capacity ◽  
Workplace Safety ◽  
Unmanned Vehicles ◽  
Use Cases ◽  
Automated Systems ◽  
Collaborative Communication ◽  
Wide Range

Automated systems have been seamlessly integrated into several industries as part of their industrial automation processes. Employing automated systems, such as autonomous vehicles, allows industries to increase productivity, benefit from a wide range of technologies and capabilities, and improve workplace safety. So far, most of the existing systems consider utilizing one type of autonomous vehicle. In this work, we propose a collaboration of different types of unmanned vehicles in maritime offshore scenarios. Providing high capacity, extended coverage, and better quality of services, autonomous collaborative systems can enable emerging maritime use cases, such as remote monitoring and navigation assistance. Motivated by these potential benefits, we propose the deployment of an Unmanned Surface Vehicle (USV) and an Unmanned Aerial Vehicle (UAV) in an autonomous collaborative communication system. Specifically, we design high-speed, directional communication links between a terrestrial control station and the two unmanned vehicles. Using measurement and simulation results, we evaluate the performance of the designed links in different communication scenarios and we show the benefits of employing multiple autonomous vehicles in the proposed communication system.

scholarly journals Estimation of leg stiffness using an approximation to the planar spring–mass system in high-speed running

2020 ◽  
Vol 17 (1) ◽  
pp. 172988141989071
Author(s):  
Wei Guo ◽  
Changrong Cai ◽  
Mantian Li ◽  
Fusheng Zha ◽  
Pengfei Wang ◽  
...  
Keyword(s):  
Analytical Solution ◽  
High Speed ◽  
Stance Phase ◽  
Center Of Mass ◽  
Critical Role ◽  
Line Center ◽  
Motion Model ◽  
Mass System ◽  
Leg Stiffness ◽  
Wide Range

Leg stiffness plays a critical role in legged robots’ speed regulation. However, the analytic solutions to the differential equations of the stance phase do not exist, of course not for the exact analytical solution of stiffness. In view of the challenge in dealing with every circumstance by numerical methods, which have been adopted to tabulate approximate answers, the “harmonic motion model” was used as approximation of the stance phase. However, the wide range leg sweep angles and small fluctuations of the “center of mass” in fast movement were overlooked. In this article, we raise a “triangle motion model” with uniform forward speed, symmetric movement, and straight-line center of mass trajectory. The characters are then shifted to a quadratic equation by Taylor expansion and obtain an approximate analytical solution. Both the numerical simulation and ADAMS-Matlab co-simulation of the control system show the accuracy of the triangle motion model method in predicting leg stiffness even in the ultra-high-speed case, and it is also adaptable to low-speed cases. The study illuminates the relationship between leg stiffness and speed, and the approximation model of the planar spring–mass system may serve as an analytical tool for leg stiffness estimation in high-speed locomotion.

scholarly journals IMPLEMENTATION OF A REDUCED COMPLEXITY HIGH PERFORMANCE DATA ACQUISITION CHIP USING 0.18 MICRON TECHNOLOGY

2021 ◽  
Vol 7 (3) ◽  
pp. 22-26
Author(s):  
Hai P. Le ◽  
◽  
Aladin Azyegh ◽  
Jugdutt Singh ◽  
◽  
...  
Keyword(s):  
Low Power ◽  
Data Acquisition ◽  
High Speed ◽  
High Performance ◽  
Modern Science ◽  
Digital Data ◽  
Clock Frequency ◽  
Flash Adc ◽  
Analog Signals ◽  
Wide Range

Data acquisition (DAQ) in the general sense is the process of collecting information from the real world. For engineers and scientists, this data is mostly numerical and is usually collected, stored and analysed using computers. However, most of the input signals cannot be read directly by digital computers. Because they are generally analog signals distinguished by continuous values, while computers can only recognise digital signals containing only the on/off levels. DAQ systems are therefore inevitably necessary, as they include the translation requirements from analog signals to digital data. For this reason, they have become significant in wide range of applications in modern science and technology [1]. The paper precents the disign of a 12-bit high-speed low-power Data Acquisition (DAQ) Chip. In this paper, the disigns of the building block components are aimed at high-accuracy along with high-speed and low power dissipation. A modifided flash Analog-to-Digital converter (ADC) was used instead of the traditional flash proposed DAQ chip operates at 1 GHz master clock frequency and achieves a sampling speed of 125 MS/s. It dissipates only 64.9 mW of power as compared to 97.2 mW when traditional flash ADC was used.

The Research Progress of Melanin

2011 ◽  
Vol 204-210 ◽  
pp. 2057-2060
Author(s):  
Jian Ming Wang ◽  
Ai Hua Ao ◽  
Chang Sheng Qiao ◽  
Yu Zhong ◽  
Yuan Yuan Zhang
Keyword(s):  
High Speed ◽  
High Performance ◽  
Analytical Techniques ◽  
Research Progress ◽  
Countercurrent Chromatography ◽  
New Techniques ◽  
Wide Range ◽  
High Performance Capillary Electrophoresis ◽  
Relationship Of ◽  
The Relationship

The sources of melanin and the sorts of melanin are introduced. New techniques for extraction and analysis of natural melanin were introduced. New analytical techniques are high performance liquid chromatography, high-speed countercurrent chromatography, high performance capillary electrophoresis and chromatography-mass spectrometry. The relationship of polyketide melanogenesis molecular biology to that of nonmelanin-producing pathways in a wide range of fungi and other organisms is discussed. The applications of melanin are introduced.

A Gigabit Fiber Optical Bus Based on the RapidIO Technology

2012 ◽  
Vol 263-266 ◽  
pp. 1021-1027
Author(s):  
Ying Qing Qian ◽  
Xiao Feng Wang ◽  
Li Lao ◽  
Yun Lu
Keyword(s):  
Distributed System ◽  
High Speed ◽  
High Performance ◽  
Fiber Optic ◽  
High Capacity ◽  
Processing Capability ◽  
Fiber Optical ◽  
Tightly Coupled ◽  
Interconnect Technology

The RapidIO architecture is an interconnect technology based on a high-performance and packet-switched interconnect technology. The paper uses the RapidIO Interconnect technology to design a fiber optic bus. The fiber optic bus provides a tightly coupled interconnect with Gigabit speed, which can improve the processing capability of the space distributed system, such as the weapons platform with high-speed and high-capacity multi-system.

Broadband Solutions for the Last Mile to Malaysian Residential Customers

2009 ◽  
pp. 164-170 ◽  
Author(s):  
Saravanan Nathan Lurudusamy
Keyword(s):  
Data Transmission ◽  
High Speed ◽  
Data Transfer ◽  
Full Range ◽  
National Policy ◽  
High Capacity ◽  
Broadband Service ◽  
Large Bandwidth ◽  
Wide Range ◽  
Policy Objectives

Broadband is a term that describes the Internet as a function of high-speed data connections and large bandwidth. The Federation Communication Commission (FCC) defines broadband service as data transmission speeds exceeding 200 kilobits per second (Kbps), or 200,000 bits per second, in at least one direction, either downstream or upstream. Its fundamental ability to bring about change in the socioeconomic fabric hinges on it being a medium for greater amount of data transmission. Briefly, high capacity bandwidth allows greater amount of information to be transmitted which is the essence of all applications and communications. It is widely predicted that Internet through broadband will quickly penetrate the residential markets that is in line with the National Broadband Plan (NBP) that focuses on infrastructure readiness and market penetration, expediting the rollout of broadband using both fixed and wireless access. The first in the list of 10 National Policy Objectives as stated in the Communications & Multimedia Act (CMA) 1998 reports the aspiration of turning Malaysia into a communications and multimedia global hub. Hashim (2006) states that a secretariat has been formed to roll out the NBP to ensure its success and to achieve the 10% of the population by 2008. Indeed, one of the fundamental strategies to accomplish such a vision is to put in place an efficient broadband network and ensure sufficient subscription to the services. Broadband is different from conventional dial-up services due to its many enhanced capabilities. It provides access to a wide range of Internet services and applications like streaming media, Internet phone, online gaming, and other interactive services. Many of these current and newly developed services are “bandwidth hungry,” thus requiring large amounts of data transfer at excessively fast speed, which may not be technically feasible with dial-up service. Therefore, broadband service may be increasingly necessary to access a full range of services and opportunities beyond what a dial-up service could potentially offer. Many residential customers who have been using traditional dial-up have been migrating to broadband. The constantly connected Internet accessibility remains another lucrative benefit for broadband converts as compared to the dial-up technology. Broadband technology does not block phone lines nor requires one to reconnect to the network after logging off. The dedicated connection for the user translates into less delay in transmission of content. A faster connection speed could allow users to access a wide range of resources, services, and products.

Knowledge-Based Medical Image Analysis and Representation for Integrating Content Definition with the Radiological Report

1995 ◽  
Vol 34 (01/02) ◽  
pp. 96-103 ◽  
Author(s):  
R. S. Mezrich ◽  
C. A. Kulikowski ◽  
L. Gong
Keyword(s):  
Image Analysis ◽  
Image Segmentation ◽  
Medical Image ◽  
High Speed ◽  
High Performance ◽  
Clinical Decision Making ◽  
Medical Image Analysis ◽  
High Capacity ◽  
Knowledge Based ◽  
Clinical Records

Abstract:Technology breakthroughs in high-speed, high-capacity, and high performance desk-top computers and workstations make the possibility of integrating multimedia medical data to better support clinical decision making, computer-aided education, and research not only attractive, but feasible. To systematically evaluate results from increasingly automated image segmentation it is necessary to correlate them with the expert judgments of radiologists and other clinical specialists interpreting the images. These are contained in increasingly computerized radiological reports and other related clinical records. But to make automated comparison feasible it is necessary to first ensure compatibility of the knowledge content of images with the descriptions contained in these records. Enough common vocabulary, language, and knowledge representation components must be represented on the computer, followed by automated extraction of image-content descriptions from the text, which can then be matched to the results of automated image segmentation. A knowledge-based approach to image segmentation is essential to obtain the structured image descriptions needed for matching against the expert’s descriptions. We have developed a new approach to medical image analysis which helps generate such descriptions: a knowledge-based object-centered hierarchical planning method for automatically composing the image analysis processes. The problem-solving steps of specialists are represented at the knowledge level in terms of goals, tasks, and domain objects and concepts separately from the implementation level for specific representations of different image types, and generic analysis methods. This system can serve as a major functional component in incrementally building and updating a structured and integrated hybrid information system of patient data. This approach has been tested for magnetic resonance image interpretation, and has achieved promising results.

Design and Study on Power Supply for Giant Magnetostrictive Accurate-Motion Actuator

2008 ◽  
Vol 392-394 ◽  
pp. 787-792
Author(s):  
M. Wu ◽  
Xi Lin Zhu
Keyword(s):  
High Speed ◽  
High Performance ◽  
Design Method ◽  
Current Source ◽  
Fast Response ◽  
Low Noise ◽  
Constant Current ◽  
Loop Current ◽  
Constant Current Source ◽  
Wide Range

The architecture and operation theory of Giant Magnetostrictive Accurate-motion Actuator have been introduced. After analysing the driving characteristic of giant magnetostrictive material and requirement of driving power, a design method of wide range and high precision NC constant-current source has been put out. The output circuit is composed of serial 12-bit DACs Max531, low-noise high-speed precision operational amplifiers OP27 and driving circuit. It provides current from 0 to 2.048A with 0.5mA step value. Two fully differential input channels 16-bit, sigma-delta ADCs AD7705 collects output current in feedback loop. Current ripple is controlled under 0.25mA through using homemade high-performance linear power. The result shows that the driving power with characteristic of high stability and fast response meets the needs of driving of Giant Magnetostrictive Accurate-motion.

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