scholarly journals Accelerometer-Based Wheel Odometer for Kinematics Determination

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1327
Author(s):  
Ahmed A. Youssef ◽  
Naif Al-Subaie ◽  
Naser El-Sheimy ◽  
Mohamed Elhabiby
Keyword(s):  
Data Processing ◽  
Inertial Sensors ◽  
Low Cost ◽  
High Capacity ◽  
Short Term ◽  
Stochastic Errors ◽  
Efficient Data ◽  
High Dynamics ◽  
Simple Assembly

Various high budget industries that utilize wheel-based vehicles rely on wheel odometry as an integral aspect of their navigation process. This research introduces a low-cost alternative for typical wheel encoders that are typically used to determine the on-track speed of vehicles. The proposed system is referred to as an Accelerometer-based Wheel Odometer for Kinematics determination (AWOK). The AWOK system comprises just a single axis accelerometer mounted radially at the center of any given wheel. The AWOK system can provide direct distances instead of just velocities, which are provided by typical wheel speedometers. Hence, the AWOK system is advantageous in comparison to typical wheel odometers. Besides, the AWOK system comprises a simple assembly with a highly efficient data processing algorithm. Additionally, the AWOK system provides a high capacity to handle high dynamics in comparison to similar approaches found in previous related work. Furthermore, the AWOK system is not affected by the inherited stochastic errors in micro-machined electro-mechanical systems (MEMS) inertial sensors, whether short-term or long-term errors. Above all, the AWOK system reported a relative accuracy of 0.15% in determining the distance covered by a car.

Response of plant functional traits at species and community levels to grazing exclusion on Inner Mongolian steppe, China

2018 ◽  
Vol 40 (2) ◽  
pp. 179 ◽  
Author(s):  
Jinghui Zhang ◽  
Yongmei Huang ◽  
Huiying Chen ◽  
Jirui Gong ◽  
Yu Qi ◽  
...  
Keyword(s):  
Growth Rate ◽  
Functional Traits ◽  
Ecosystem Function ◽  
High Capacity ◽  
Plant Functional Traits ◽  
Grazing Management ◽  
Short Term ◽  
Grazing Exclusion ◽  
Typical Steppe

Variations in ecosystem function in response to land-use changes may be expected to reflect differences in the functional traits of plants. In this study, we sought to reveal the relationship between trait variability and grazing management on typical steppe in Inner Mongolia, and explore the implications of this relationship for ecosystem functioning. We measured aboveground biomass and 18 functional traits of the most abundant plant species in a grassland subject to three grazing-management regimes: long-term grazing, short-term grazing exclusion (since 2008) and long-term grazing exclusion (since 1956). Principal component analysis of the variation in species-level traits revealed trade-offs between the traits that enabled rapid acquisition of resources by fast-growing annual species and those that promoted conservation of resources by perennial grasses, especially Stipa grandis. However, there was no systematic pattern of intra-specific variation in trait values recorded among sites. Aggregation of plant functional traits to the community level revealed a gradient of responses of typical steppe to grazing exclusion. Long-term grazing favoured species whose traits indicate low forage quality and relatively low growth rate. Exclusion of grazing for several years favoured species whose traits indicate relatively high growth rate and high capacity to acquire resources. Exclusion of grazing for several decades favoured species whose morphological and physiological traits indicated low growth rates and high capacity for resource conservation. These community-level traits imply that ecosystem carbon and nutrient stores will change in response to the grazing regime. Long-term grazing will result in decreased plant carbon and nitrogen content, and will lead to carbon and nutrient loss, whereas short-term and long-term grazing exclusion are beneficial to the recovery of carbon and nutrient storage. The findings support the value of community aggregated traits as indicators of environmental or management change and for explaining changes in ecosystem function.

Kinodynamic planning for spherical tensegrity locomotion with effective gait primitives

2019 ◽  
Vol 38 (12-13) ◽  
pp. 1442-1462 ◽  
Author(s):  
Zakary Littlefield ◽  
David Surovik ◽  
Massimo Vespignani ◽  
Jonathan Bruce ◽  
Weifu Wang ◽  
...  
Keyword(s):  
Low Cost ◽  
Complex Environments ◽  
Dynamic Nature ◽  
Short Term ◽  
Dynamic Motion ◽  
Dynamical Characteristics ◽  
Unstable Configuration ◽  
Numerical Process ◽  
Horizon Planning

Tensegrity-based robots can achieve locomotion through shape deformation and compliance. They are highly adaptable to their surroundings, and are lightweight, low cost, and physically robust. Their high dimensionality and strongly dynamic nature, however, can complicate motion planning. Efforts to date have primarily considered quasi-static reconfiguration and short-term dynamic motion of tensegrity robots, which do not fully exploit the underlying system dynamics in the long term. Longer-horizon planning has previously required costly search over the full space of valid control inputs. This work synthesizes new and existing approaches to produce dynamic long-term motion while balancing the computational demand. A numerical process based upon quasi-static assumptions is first applied to deform the system into an unstable configuration, causing forward motion. The dynamical characteristics of the result are then altered via a few simple parameters to produce a small but diverse set of useful behaviors. The proposed approach takes advantage of identified symmetries on the prototypical spherical tensegrity robot, which reduce the number of needed gaits but allow motion along different directions. These gaits are first combined with a standard search method to achieve long-term planning in environments where the developed gaits are effective. For more complex environments, the various motion primitives are paired with the fall-back option of random valid actions and are used by an informed sampling-based kinodynamic motion planner with anytime properties. Evaluations using a physics-based model for the prototypical robot demonstrate that modest but efficiently applied search effort can unlock the utility of dynamic tensegrity motion to produce high-quality solutions.

scholarly journals Comparative Analysis of Executive Compensation in the Republic of Serbia and EU Countries

2019 ◽  
Vol 57 (2) ◽  
pp. 181-200
Author(s):  
Ivana Marinović Matović
Keyword(s):  
Comparative Analysis ◽  
Executive Compensation ◽  
High Capacity ◽  
Business Organization ◽  
Business Organizations ◽  
Short Term ◽  
Eu Countries ◽  
Strong Motivation ◽  
The Republic

AbstractExecutive compensations have a strong motivation role in contemporary business organizations. Adequate models of compensation enable attracting and retaining the high-capacity managers. This way, business organization conquers and maintains the competitive position in the context of globalization. It is necessary to align the executive compensation with the business organization’s strategy, which requires careful process of planning, done by the highest levels of management and ownership. The main objective of the paper is to explore and compare the structure and the level of executive compensation in the Republic of Serbia and EU countries. The paper focuses on executive compensation components, primarily long-term and short-term incentives, as well as sallary and benefits. A comparative analysis of executive compensation models was performed to explain the differences in the observed countries.The study found large and disproportionate differences in the executive compensation levels, conditioned mostly by the economic development of the observed economies.

scholarly journals More science with less: evaluation of a 3D-printed weather station

2020 ◽  
Vol 13 (9) ◽  
pp. 4699-4713
Author(s):  
Adam Theisen ◽  
Max Ungar ◽  
Bryan Sheridan ◽  
Bradley G. Illston
Keyword(s):  
Atmospheric Pressure ◽  
Low Cost ◽  
Weather Station ◽  
Short Term ◽  
Oklahoma Mesonet ◽  
System Temperature ◽  
3D Printed ◽  
Field Deployment ◽  
The University

Abstract. A weather station built using 3D-printed parts and low-cost sensors, based on plans and guidance provided by the University Corporation for Atmospheric Research 3D-Printed Automatic Weather Station Initiative, was deployed alongside an Oklahoma Mesonet station to compare its performance against standard commercial sensors and determine the longevity and durability of the system. Temperature, relative humidity, atmospheric pressure, wind speed and direction, solar radiation, and precipitation measurements were collected over an 8-month field deployment in Norman, Oklahoma. Measurements were comparable to the commercial sensors except for wind direction, which proved to be problematic. Longevity and durability of the system varied, as some sensors and 3D-printed components failed during the deployment. Overall, results show that these low-cost sensors are comparable to the more expensive commercial counterparts and could serve as viable alternatives for researchers and educators with limited resources for short-term deployments. Long-term deployments are feasible with proper maintenance and regular replacement of sensors and 3D-printed components.

A computer program for use in sheep enterprise decision making.

1981 ◽  
Vol 3 (1) ◽  
pp. 110
Author(s):  
HG Gardiner ◽  
KR Shackleton
Keyword(s):  
Computer Program ◽  
Low Cost ◽  
Management Strategies ◽  
Long Term Effects ◽  
Short Term ◽  
Management Decisions ◽  
Department Of Agriculture ◽  
Advantages And Disadvantages ◽  
Kitchen Table

The profitability and long term viability of any business enterprise depends on careful, well thought out, long term planning. The pastoral industry is no exception and management decisions need to be based on the long term as well as short term advantages and disadvantages of any parficular strategy. Examination of the long term effects of management decisions has always been difficult. Not only is the future uncertain but the necessary financial and stock calculations are tedious, particularly if several strategies are considered. A computer program, suitable for use on programmable calculators, has been designed with the specific aim of reducing the tedium of calculation. Emphasis in the design has been placed on flexibility and applicability to actual decsion making situations. The program, devised for use on the Hewlett Packard 41C calculator, is very similar in aim to the model reported by Barber (I 9801, which aimed 'to provide a tool for producers, extension workers and researchers that could be used anywhere from the office desk to the kitchen table'. A recent summary of enterprise modelling work in 'Computers in Farming' (Department of Agriculture, Victoria 1980) indicates that most of the modelling work has been centred around larger, less portable micro-computers. The ease of operation, transportability and low cost of programmable calculators should make them a valuable tool for use on properties by managers. owners, extension workers, bankers and stock agents. They will enable the manager quickly and accurately to assess the likely outcome of various management strategies.

scholarly journals A Robust EMD-Based RVFL Network Fusion Algorithm for Low-Cost GPS/INS Integrated System

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Da Liu ◽  
Shufang Zhang ◽  
Jingbo Zhang
Keyword(s):  
Inertial Sensors ◽  
Low Cost ◽  
Integrated System ◽  
Fusion Algorithm ◽  
Functional Link ◽  
Mode Decomposition ◽  
Error Accumulation ◽  
Lower Complexity ◽  
High Level

Global positioning system (GPS) and inertial navigation system (INS) are commonly combined to overcome disadvantages of each and constitute an integrated system that realizes long-term precision. However, the performance of the integrated system deteriorates on which GPS is unavailable. Especially when low-cost inertial sensors based on the microelectromechanical system (MEMS) are used, performance of the integrated system degrades severely over time. In this study, in order to minimize the adverse impact of high-level stochastic noise from low-cost MEMS sensors, denoising technology based on empirical mode decomposition (EMD) is employed to improve signal quality before navigation solution by which significant improvement of removing noise is achieved. Moreover, a random vector functional link (RVFL) network-based fusion algorithm is presented to estimate and compensate position error during GPS outage such that error accumulation is suppressed quickly when INS is working standalone. Performance of the proposed approach is evaluated by experimental results. It is indicated from comparison that the proposed algorithm takes advantages such as better accuracy and lower complexity and is more robust than the commonly reported methods and is more appropriate for real-time and low-cost application.

Compensation for Stochastic Error of Gyros in a Dual-axis Rotational Inertial Navigation System

2015 ◽  
Vol 69 (1) ◽  
pp. 169-182 ◽  
Author(s):  
Zhichao Zheng ◽  
Songlai Han ◽  
Jin Yue ◽  
Linglong Yuan
Keyword(s):  
Navigation System ◽  
High Performance ◽  
Inertial Navigation System ◽  
Inertial Sensors ◽  
Inertial Sensor ◽  
Low Cost ◽  
Inertial Navigation ◽  
Field Tests ◽  
Stochastic Error ◽  
Stochastic Errors

A dual-axis rotational Inertial Navigation System (INS) has received wide attention in recent years because of high performance and low cost. However, some errors of inertial sensors such as stochastic errors are not averaged out automatically during navigation. Therefore a Twice Position-fix Reset (TPR) method is provided to enhance accuracy of a dual-axis rotational INS by compensating stochastic errors. According to characteristics of an azimuth error introduced by stochastic errors of an inertial sensor in the dual-axis rotational INS, both an azimuth error and a radial-position error are much better corrected by the TPR method based on an optimised error propagation equation. As a result, accuracy of the dual-axis rotational INS is prominently enhanced by the TPR method, as is verified by simulations and field tests.

Associations across time: The hippocampus as a temporary memory store

1985 ◽  
Vol 8 (3) ◽  
pp. 479-497 ◽  
Author(s):  
J. N. P. Rawlins
Keyword(s):  
High Capacity ◽  
Hippocampal Damage ◽  
Limited Capacity ◽  
Short Term ◽  
Long Term Storage ◽  
Memory Store ◽  
Complementary Set ◽  
Temporary Memory ◽  
Term Storage

AbstractAll recent memory theories of hippocampal function have incorporated the idea that the hippocampus is required to process items only of some qualitatively specifiahle kind, and is not required to process items of some complementary set. In contrast, it is now proposed that the hippocampus is needed to process stimuli of all kinds, but only when there is a need to associate those stimuli with other events that are temporally discontiguous. In order to form or use temporally discontiguous associations, it is essential to maintain some memory of the first component until the second component has occurred. When the temporal gap to he spanned is small, and the number of items to be temporarily retained is low, a limited-capacity, short-term store is sufficient to allow associations to be formed. Such a store is presumed to operate in parallel with the hippocampus in normal animals. Hippocampal damage disrupts a much higher-capacity store that has a slower decay rate, and so leaves animals with only a very limited ability to form temporally discontiguous associations. Hippocampal damage, however, is not held to affect the long-term storage of associations of any kind, if they can be formed. Analyses of both new and existing data are presented to show that by classifying tasks in terms of the need to use a temporary memory store to retain temporally discontiguous information one can cut right across existing classifications as well as achieve a better fit to the data. The hippocampus thus seems best described as a high-capacity, intermediate-term memory store.

EXPRESS: Early Cost Realization and College Choice

2021 ◽  
pp. 002224372110263
Author(s):  
Haewon Yoon ◽  
Yang Yang ◽  
Carey K. Morewedge
Keyword(s):  
Student Loans ◽  
Low Cost ◽  
Investment Decision ◽  
Cash Flows ◽  
Short Term ◽  
Non Profit ◽  
Financial Costs ◽  
Financial Decision ◽  
Short Term Investment

We propose a formal tuition myopia model of the decision-making process by which students evaluate the financial costs and returns of college. In simulations, surveys, and experiments, we find that even when student loans defer payment of attendance costs until after graduation—the same moment when students can begin earning a salary that reflects their degree—students psychologically realize the financial costs of college much earlier. This early cost realization frames a majority of choices between any pair of colleges as an intertemporal tradeoff between a smaller short-term investment with smaller long-term returns (a low cost-low return college; LC-LR) and a larger short-term investment with larger long-term returns (a high cost-high return college; HC-HR). While a rational model based on projected future cash flows most often favors the HC-HR college, our model predicts a preference for the LC-LR college among students who are financially impatient and in choice pairs where the equilibrium between LC-LR and HC-HR options is at a low discount rate threshold. Our model of a life-altering financial decision that affects millions of students each year offers valuable insights for universities, policymakers, and non-profit organizations advocating for students to treat higher education as an investment decision.

scholarly journals A high-capacity cathode for rechargeable K-metal battery based on reversible superoxide-peroxide conversion

2020 ◽  
Author(s):  
Yu Qiao ◽  
Han Deng ◽  
Zhi Chang ◽  
Xin Cao ◽  
Huijun Yang ◽  
...  
Keyword(s):  
Low Cost ◽  
High Capacity ◽  
High Energy ◽  
Redox Activity ◽  
Storage Device ◽  
O2 Evolution ◽  
Energy Storage Device ◽  
Limited Capacity ◽  
Metal Anode

Abstract As a promising low-cost energy storage device, the development of rechargeable potassium-ion battery (KIB) is severely hindered by the limited capacity of cathode candidates. Regarded as an attractive capacity-boosting strategy, triggering the O-related anionic redox activity has not been achieved within sealed KIB system. Herein, different from the typical gaseous open K-O2 battery (O2/KO2 redox), we originally realize the reversible superoxide/peroxide (KO2/K2O2) interconversion on a KO2-based cathode. Controlled within a sealed cell environment, the irreversible O2 evolution and electrolyte decomposition (induced by superoxide anion (O2−) formation) are effectively restrained. Rationally controlling the reversible depth-of-charge at 300 mAh/g (based on the mass of KO2), no obvious cell degradation can be observed during 900 cycles. Moreover, benefit from electrolyte modification, KO2-based cathode is coupled with limited amount of K-metal anode (merely 2.5 times excess), harvesting a K-metal full-cell with high-energy-efficiency (∼90%) and long-term cycling stability (over 300 cycles).

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