itKD: Interchange Transfer-based Knowledge Distillation for 3D Object Detection

Recently, point-cloud based 3D object detectors have achieved remarkable progress. However, most studies are limited to the development of deep learning architectures for improving only their accuracy. In this paper, we propose an autoencoder-style framework comprising channel-wise compression and decompression via interchange transfer for knowledge distillation. To learn the map-view feature of a teacher network, the features from a teacher and student network are independently passed through the shared autoencoder; here, we use a compressed representation loss that binds the channel-wised compression knowledge from both the networks as a kind of regularization. The decompressed features are transferred in opposite directions to reduce the gap in the interchange reconstructions. Lastly, we present an attentive head loss for matching the pivotal detection information drawn by the multi-head self-attention mechanism. Through extensive experiments, we verify that our method can learn the lightweight model that is well-aligned with the 3D point cloud detection task and we demonstrate its superiority using the well-known public datasets Waymo and nuScenes.Comment: 12 pages, 2 figures, 8 table

Quantitative Evaluation of Food-Waste Components in Organic Fertilizer Using Visible–Near-Infrared Hyperspectral Imaging

Excessive addition of food waste fertilizer to organic fertilizer (OF) is forbidden in the Republic of Korea because of high sodium chloride and capsaicin concentrations in Korean food. Thus, rapid and nondestructive evaluation techniques are required. The objective of this study is to quantitatively evaluate food-waste components (FWCs) using hyperspectral imaging (HSI) in the visible–near-infrared (Vis/NIR) region. A HSI system for evaluating fertilizer components and prediction algorithms based on partial least squares (PLS) analysis and least squares support vector machines (LS-SVM) are developed. PLS and LS-SVM preprocessing methods are employed and compared to select the optimal of two chemometrics methods. Finally, distribution maps visualized using the LS-SVM model are created to interpret the dynamic changes in the OF FWCs with increasing FWC concentration. The developed model quantitively evaluates the OF FWCs with a coefficient of determination of 0.83 between the predicted and actual values. The developed Vis/NIR HIS system and optimized model exhibit high potential for OF FWC discrimination and quantitative evaluation

Tailoring Pressure Sensitive Adhesives with H6XDI-PEG Diacrylate for Strong Adhesive Strength and Rapid Strain Recovery

The development of flexible electronic technology has led to convenient devices, including foldable displays, wearable, e-skin, and medical devices, increasing the need for flexible adhesives that can quickly recover their shape while connecting the components of the device. Conventional pressure sensitive adhesives (PSAs) can improve recoverability via crosslinking, but often have poor adhesive strength. In this study, new types of urethane-based crosslinkers are synthesized using m-xylylene diisocyanate (XDI) or 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI) as a hard segment, and poly(ethylene glycol) (PEG) group as a soft segment. The PSA with the synthesized H6XDI-PEG diacrylate (HPD) demonstrates a significantly improved recoverability compared to XDI-PEG diacrylate and a conventional crosslinker 1,6-hexanediol diacrylate (HDDA) while maintaining high adhesion strength (& AP;25.5 N 25 mm(-1)). The excellent recovery property of the PSA crosslinked with HPD is further confirmed by 100k folding tests and 10k multi-directional stretching tests exhibiting high folding and stretching stability. PSA with HPD also shows high optical transmittance (> 90%) even after 20% straining, suggesting its applicability in fields that simultaneously require high flexibility, recoverability, and optical clarity such as foldable displays

Measurement of Magnetic Field Properties of a 3.0 T/m Air-core HTS Quadrupole Magnet and Optimal Shape Design to Increase the Critical Current Reduced by the Incident Magnetic Field

Air-core high-temperature superconducting quadrupole magnets (AHQMs) differ from conventional iron-core quadrupole magnets, in that their iron cores are removed, and instead high-temperature superconductors (HTSs) are applied. The high operating temperature and high thermal stability of HTS magnets can improve their thermodynamic cooling efficiency. Thus, HTS magnets are more suitable than low temperature superconducting magnets for withstanding radiation and high heat loads in the hot cells of accelerators. AHQMs are advantageous because they are compact, light, and free from the hysteresis of ferromagnetic materials, due to the removal of the iron-core. To verify the feasibility of the use of AHQMs, we designed and fabricated a 3.0 T/m AHQM. The magnetic field properties of the fabricated AHQM were evaluated. Additionally, the characteristics of the air-core model and iron-core model of 9.0 T/m were compared in the scale for practical operation. In comparison with the iron-core model, AHQM significantly reduces the critical current (I[subscript C]) due to the strong magnetic field inside the coil. In this study, a method for the accurate calculation of I[subscript C] is introduced, and the calculated results are compared with measured results. Furthermore, the optimal shape design of the AHQM to increase the critical current is introduced. Keywords: air-core quadrupole magnet; critical current degradation; heavy-lon accelerator; high-temperature superconductor; iron-core quadrupole magnet; optimum shape designKorea Electric Power Corporation (Grant R17XA05_32)“Human Resources Program in Energy Technology” of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry and Energy, Republic of Korea. (No. 20184030202270

Ambient air-operated thermo-switchable adhesion of N-isopropylacrylamide-incorporated pressure sensitive adhesives

Owing to the rise in global population and living standards, waste treatment has inevitably become a critical issue for a sustainable environment. In particular, for an effective recycling process, it is vital to disassemble different types of materials by removing adhesives used in the packaging. However, this removal process requires harsh solvents (acidic and organic) that are unfriendly to nature and may cause additional pollution. To address this issue, functional adhesive materials that can be removed without the use of harsh solvents have drawn significant attention. One promising approach is to utilize the stimuli-responsive polymers to synthesize pressure sensitive adhesives (PSAs); however, it is technically challenging to simultaneously satisfy (i) strong initial adhesion (without stimulus), (ii) stimuli-responsive sufficient reduction of adhesion, and (iii) reversibility. In this study, thermo-switchable PSAs were synthesized by copolymerizing N-isopropylacrylamide (NIPAM), which possesses thermal-responsive properties; acrylic acid, which endows adhesive properties; and 2-ethylhexyl acrylate, which has a low glass transition temperature to attain sufficient flexibility. The synthesized NIPAM-based thermo-switchable PSAs exhibited significantly high peel strength at room temperature (similar to 15.41 N/25 mm at 20 degrees C), which decreased by similar to 97% upon heating (similar to 0.46 N/25 mm at 80 degrees C). Importantly, no residues remained due to the cohesive nature of NIPAM at high temperature. The reversible adhesion behaviour of the thermo-switchable PSAs was retained during repeated heating and cooling cycles. Therefore, the developed thermo-switchable PSA can enhance the reusability and recyclability of valuable materials and minimize the use of toxic chemicals for adhesive removal, contributing to a more sustainable future

Prevention of Carbon Corrosion by TiC Formation on Ti Current Collector in Seawater Batteries

Seawater batteries (SWBs) are a type of sodium-air batteries that use abundant seawater as the source of the catholyte. A cathode current collector in traditional SWBs is composed of titanium (Ti) and carbon-based current collectors. The high contact resistance between Ti and carbon-based current collectors as well as the slow kinetics of oxygen evolution and reduction reactions increase the overpotential, resulting in side reactions such as carbon corrosion. To enhance the performance of SWBs, previous studies have focused on carbon current collectors, catalysts, and polymer binders, while ignoring the importance of Ti. In this study, a facile carbon diffusion technique is employed to successfully form titanium carbide (TiC) on the surface of Ti. SWBs with engineered Ti demonstrate considerably improved performance (four times higher cycling stability, 30% increased power performance, 40% reduced voltage gap) in relation to those with pristine Ti. This significantly improved electrochemical performance is found to be attributable to the prevention of carbon corrosion due to i) the reduction of contact resistance (owing to rough TiC surface) and ii) the electrocatalytic effect of TiC. Finally, engineered Ti is applied to large-area SWBs and its potential applicability in energy storage systems is confirmed