Flutter analysis and mode tracking of aircraft model based on piecewise interpolation method

This study reveals the existence of mode tracking errors in the flutter analysis based on the piecewise quadratic interpolation of aerodynamic forces. To solve the problem, a predictor-corrector scheme for mode tracking is added into the piecewise quadratic interpolation method. Numerical results indicate that method proposed provides right and accurate mode tracking

DCA: Diversified Co-Attention towards Informative Live Video Commenting

We focus on the task of Automatic Live Video Commenting (ALVC), which aims to generate real-time video comments with both video frames and other viewers' comments as inputs. A major challenge in this task is how to properly leverage the rich and diverse information carried by video and text. In this paper, we aim to collect diversified information from video and text for informative comment generation. To achieve this, we propose a Diversified Co-Attention (DCA) model for this task. Our model builds bidirectional interactions between video frames and surrounding comments from multiple perspectives via metric learning, to collect a diversified and informative context for comment generation. We also propose an effective parameter orthogonalization technique to avoid excessive overlap of information learned from different perspectives. Results show that our approach outperforms existing methods in the ALVC task, achieving new state-of-the-art results

Multi-Contact Force-Sensing Guitar for Training and Therapy

Hand injuries from repetitive high-strain and physical overload can hamper or even end a musician's career. To help musicians develop safer playing habits, we developed a multiplecontact force-sensing array that can substitute as a guitar fretboard. The system consists of 72 individual force sensing modules, each containing a flexure and a photointerrupter that measures the corresponding deflection when forces are applied. The system is capable of measuring forces between 0-25 N applied anywhere within the first 12 frets at a rate of 20 Hz with an average accuracy of 0.4 N and a resolution of 0.1 N. Accompanied with a GUI, the resulting prototype was received positively as a useful tool for learning and injury prevention by novice and expert musicians.Comment: IEEE Sensor Conference, 201

Urban Building Energy Modeling with Parameterized Geometry and Detailed Thermal Zones for Complex Building Types

Urban building energy modeling (UBEM) has attracted wide attention to the requirement for global carbon emission reduction. This paper presents a UBEM tool, AutoBPS-Param, to generate building energy models (BEMs) with parameterized geometry and detailed thermal zones, especially for complex building types, considering the shading effect from surrounding buildings simultaneously. Three building number scales and four scenarios were analyzed in the hotel-related buildings in Changsha, China. For the prototype modeling of Scenario 1, eighteen prototype building energy models for six building types in three vintages were created, and their simulation results were aggregated based on their representative floor areas. For AutoBPS-Param of Scenario 4, the method created one EnergyPlus (Version: 9.3.0) model for each building. The geometry of the prototype model was scaled and modified based on the target building’s length, width, and number of stories. The surrounding buildings were also added to the AutoBPS-Param simulation to better capture the urban dynamic impact. The results showed that the annual electricity and natural gas energy use intensity (EUI) of the pre-2005 HotelOffice prototype model was 172.25 and 140.45 kWh/m2. In contrast, with the AutoBPS-Param method, the annual electricity EUIs of 71 HotelOffice buildings constructed before 2005 ranged from 159.51 to 213.58 kWh/m2 with an average of 173.14 kWh/m2, and the annual gas EUIs ranged from 68.02 to 229.12 kWh/m2 with an average of 108.89 kWh/m2. The proposed method can better capture the diversity of urban building energy consumption

Rapid Building Energy Modeling Using Prototype Model and Automatic Model Calibration for Retrofit Analysis with Uncertainty

Building performance simulation can be used for retrofit analysis. However, it is time-consuming to create building energy models for existing buildings. This paper presented and implemented a rapid building energy modeling method for existing buildings by using prototype models and automatic model calibration for retrofit analysis with uncertainty. A shopping mall building located in Changsha, China, was selected as a case study to demonstrate the rapid modeling method. First, a toolkit named AutoBPS-Param was developed to generate building energy models with parameterized geometry data. A baseline EnergyPlus model was generated based on the building’s basic information, including vintage, climate zone, total floor area, and percentage of each function type. Next, Monte Carlo sampling was applied to generate 1000 combinations for fourteen parameters. One thousand EnergyPlus models were created by modifying the baseline model with each parameter combination. Moreover, the 1000 simulation results were compared with the measured monthly electricity and natural gas usage data to find 29 calibrated solutions. Finally, the 29 calibrated energy models were used to evaluate the energy-saving potential of three energy conservation measures with uncertainty. The retrofit analysis results indicated that the electrical energy saving percentage of chiller replacement ranged from 1.57% to 13.51%, with an average of 8.27%. The energy-saving rate of lighting system replacement ranged from 1.92% to 11.66%, with an average of 6.43%. The energy-saving rate of window replacement ranges from 0.31% to 1.81%, with an average of 0.55%. The results showed that AutoBPS-Param could rapidly create building energy models for existing buildings and can be used for retrofit analysis after model calibration

The complete mitochondrial genome of Lymantria xylina with phylogenetic analysis

Lymantria xylina (Lepidoptera: Lymantriidae) is an important forest pest in some Asian countries. In this study, we determined the complete mitochondrial genome of L. xylina. The length of the genome is 15,488 bp and contains 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and an A + T-rich region. All PCGs use ATN as start codon and TAA as stop codon except for cox2 and nad4. The A + T-content of the genome is 80.64% and show the bias of nucleotides. We reconstructed the sister group relationship of (L. xylina + (L. dispar + Lymantria sp. AN-2017))

Sustainable cooling/lubrication induced thermo-mechanical effects on ultrasonic vibration helical milling of CFRP/Ti–6Al–4V stacks

Sustainable cooling/lubrication strategies including dry, minimum quantity lubrication (MQL), cryogenic (LN2) and hybrid (MQL and LN2) were used in ultrasonic vibration helical milling (UVHM) machining to improve the performance of hole-making for CFRP/Ti–6Al–4V stacks. The machining temperatures and forces were measured to characterize the thermo-mechanical effects on UVHM with different cooling/lubrication conditions. The machining temperatures at cryogenic conditions were −146 °C, −170 °C and −53 °C at CFRP layer, interface and Ti–6Al–4V layer, respectively. Axial and radial resultant forces at different conditions were highly related to the cutting temperature. Fiber removal mechanism at different conditions was analyzed according to the cutting temperatures, forces and the kinematic analysis in UVHM. Effects of sustainable cooling strategies and ultrasonic vibration on the hole surface texture of Ti–6Al–4V alloy were discussed. The amplitudes at different conditions varied approximately from 3.5 to 7 μm due to the variation of the forces. High precision of the exit geometry was achieved, as the height of hole exit burrs at Ti–6Al–4V layer were less than 40 μm except for the cryogenic condition. Diameters at the MQL and hybrid conditions were closer to the target diameter (ϕ10 mm), and the precision of the cylindricity of the machined holes of the stacks with the MQL and hybrid cooling conditions was higher than those at other conditions. Tool wear at different conditions were analyzed according to the SEM and EDS results. This work provided the fundamental understand of the hybrid process with sustainable cooling/lubrication strategy in UVHM machining. High quality of holes in CFRP/Ti–6Al–4V stacks were achieved by the hybrid processes