762,389 research outputs found
Energy modeling & design of prototype hydroponic grow system
Energy and food security relies on innovations that spur sustainable ideologies. This project considers a novel approach to grow microgreens within a controlled environment in a manner that conserves water, minimizes environmental impacts from agriculture runoff, and enables successful agriculture in virtually any environment. The eQUEST® software package, an energy simulator, has been used to create a model of the “grow box” considered in this study. The dimensions were specified, and heating, cooling, and other loads were incorporated into the model which was used to estimate energy consumption. Real-time data were collected from sensors installed in the container and were analyzed in Excel and used to validate model performance. The modeling approach allowed for multiple locations to be selected in eQUEST® in order to simulate energy consumption within different climates, and simulations are used to size renewable energy systems and storage in future iterations of the grow box. Potential future applications include military deployments, disaster relief, and urban developments. Grow boxes that completely utilize renewable sources and battery storage will bring these applications to fruition
An electromagnetic wearable 3-DoF resonance human body motion energy harvester using ferrofluid as a lubricant
Wearable energy harvester offers clean and continuous power for wearable sensors or devices, and plays an important role in a wide range of applications such as the health monitoring and motion track. In this study, we investigate a small electromagnetic resonance wearable kinetic energy harvester. It consists of a permanent magnet (PM) supported by two elastic strings within a rectangular box form a 3-degree-of-freedom (3-DoF) vibrator. Copper windings are attached to the outer surface of the box to generate electrical energy when the PM is forced to vibrate. To minimize any frictional losses, ferrofluid is used such that the poles of PM are cushioned by the ferrofluid, to the effect that the PM will not touch the inner of the box. Simulation results show that the ferrofluid can keep the PM ‘contactless’ from the box even subject to 10 times gravity acceleration. A prototype is built and tested under different loading conditions. Resistance load experimental results indicate the proposed harvester can generate 1.11.1 mW in walking condition and 2.282.28 mW in running condition. An energy storage circuit is employed and the energy storage experimental results show that the average storage power during walking and running conditions are 0.0140.014 mW and 0.1490.149 mW respectively. It is shown that the developed harvester can be readily attached on a shoe to offer continuous power supply for wearable sensors and devices
Verification of Resilient Communication Models for the Simulation of a Highly Adaptive Energy-Efficient Computer
Delivering high performance in an energy-efficient manner is of great importance in conducting research in computational sciences and in daily use of technology. From a computing perspective, a novel concept (the HAEC Box) has been proposed that utilizes innovative ideas of optical and wireless chip-to-chip communication to allow a new level of runtime adaptivity for future computers, which is required to achieve high performance and energy efficiency. HAEC-SIM is an integrated simulation environment designed for the study of the performance and energy costs of the HAEC Box running communication-intensive applications. In this work, we conduct a verification of the implementation of three resilient communication models in HAEC-SIM. The verification involves two NAS Parallel Benchmarks and their simulated execution on a 3D torus system with 16x16x16 nodes with Infiniband links. The simulation results are consistent with those of an independent implementation. Thus, the HAEC-SIM based simulations are accurate in this regard. Delivering high performance in an energy-efficient manner is of great importance in conducting research in computational sciences and in daily use of technology. From a computing perspective, a novel concept (the HAEC Box) has been proposed that utilizes innovative ideas of optical and wireless chip-to-chip communication to allow a new level of runtime adaptivity for future computers, which is required to achieve high performance and energy efficiency. HAEC-SIM is an integrated simulation environment designed for the study of the performance and energy costs of the HAEC Box running communication-intensive applications.In this work, we conduct a verification of the implementation of three resilient communication models in HAEC-SIM. The verification involves two NAS Parallel Benchmarks and their simulated execution on a 3D torus system with 16x16x16 nodes with Infiniband links. The simulation results are consistent with those of an independent implementation.Thus, the HAEC-SIM based simulations are accurate in this regard
Black-box optimization for integer-variable problems using Ising machines and factorization machines
Black-box optimization has potential in numerous applications such as
hyperparameter optimization in machine learning and optimization in design of
experiments. Ising machines are useful for binary optimization problems because
variables can be represented by a single binary variable of Ising machines.
However, conventional approaches using an Ising machine cannot handle black-box
optimization problems with non-binary values. To overcome this limitation, we
propose an approach for integer-variable black-box optimization problems by
using Ising/annealing machines and factorization machines in cooperation with
three different integer-encoding methods. The performance of our approach is
numerically evaluated with different encoding methods using a simple problem of
calculating the energy of the hydrogen molecule in the most stable state. The
proposed approach can calculate the energy using any of the integer-encoding
methods. However, one-hot encoding is useful for problems with a small size.Comment: 12 pages, 5 figure
Piezoelectric energy harvesting from raised crosswalk devices
This paper presents the main characteristics of an experimental energy harvesting device that can be used to recover energy from the vehicular and pedestrian traffic. The use of a piezoelectric bender devices leads to a innovative approach to Henergy Harvesting. The study focuses on the definition and specification of a mechanical configuration able to transfer the vibration from the main box to the piezoelectric transducer. The piezoelectric devices tested is the commonly used monolithic piezoceramic material lead-zirconate-titanate (PZT). The experimental results estimate the efficiency of this device tested and identify the feasibility of their use in real world applications. The results presented in this paper show the potential of piezoelectric materials for use in power harvesting applications
Building energy prediction models and related uncertainties: a review
Building energy usage has been an important issue in recent decades, and energy prediction models are important tools for analysing this problem. This study provides a comprehensive review of building energy prediction models and uncertainties in the models. First, this paper introduces three types of prediction methods: white-box models, black-box models, and grey-box models. The principles, strengths, shortcomings, and applications of every model are discussed systematically. Second, this paper analyses prediction model uncertainties in terms of human, building, and weather factors. Finally, the research gaps in predicting building energy consumption are summarised in order to guide the optimisation of building energy prediction methods
Quasi-static crushing response of square hybrid carbon/aramid tube for automotive crash box application
One of the essential automotive parts is a crash box, which is essential for initial kinetic energy absorption. However, both vehicle weight and energy-absorbing performance of crash box requirements have to achieve. Recently, crash boxes made of hybrid materials have increasingly studied regarding their better crash performance and weight reduction effects compared to conventional metallic materials. Therefore, the aim of this study is to fabricate a hybrid carbon/aramid composite crash box with a hollow structure and to determine its mechanical properties under quasi-static axial compressive and tensile loading. This study shows that square hybrid carbon/aramid tubes provide an average 57.94 J energy absorption, average 0.72 kJ/kg specific energy absorption, average 62.46 kN crushing peak load, average 748.40 MPa compressive modulus and average 36.29 MPa maximum stress under quasi-static compressive loading. It is suggested that a square hybrid carbon/aramid tube could have the promising potential to replace aluminium or metallic structure to use as an automotive crash box for lightweight applications
Multi-objective constrained optimization for energy applications via tree ensembles
Energy systems optimization problems are complex due to strongly non-linear system behavior and multiple competing objectives, e.g. economic gain vs. environmental impact. Moreover, a large number of input variables and different variable types, e.g. continuous and categorical, are challenges commonly present in real-world applications. In some cases, proposed optimal solutions need to obey explicit input constraints related to physical properties or safety-critical operating conditions. This paper proposes a novel data-driven strategy using tree ensembles for constrained multi-objective optimization of black-box problems with heterogeneous variable spaces for which underlying system dynamics are either too complex to model or unknown. In an extensive case study comprised of synthetic benchmarks and relevant energy applications we demonstrate the competitive performance and sampling efficiency of the proposed algorithm compared to other state-of-the-art tools, making it a useful all-in-one solution for real-world applications with limited evaluation budgets
- …