Privacy Safe Representation Learning via Frequency Filtering Encoder

Deep learning models are increasingly deployed in real-world applications. These models are often deployed on the server-side and receive user data in an information-rich representation to solve a specific task, such as image classification. Since images can contain sensitive information, which users might not be willing to share, privacy protection becomes increasingly important. Adversarial Representation Learning (ARL) is a common approach to train an encoder that runs on the client-side and obfuscates an image. It is assumed, that the obfuscated image can safely be transmitted and used for the task on the server without privacy concerns. However, in this work, we find that training a reconstruction attacker can successfully recover the original image of existing ARL methods. To this end, we introduce a novel ARL method enhanced through low-pass filtering, limiting the available information amount to be encoded in the frequency domain. Our experimental results reveal that our approach withstands reconstruction attacks while outperforming previous state-of-the-art methods regarding the privacy-utility trade-off. We further conduct a user study to qualitatively assess our defense of the reconstruction attack.Comment: The IJCAI-ECAI-22 Workshop on Artificial Intelligence Safety (AISafety 2022

Universal Bounding Box Regression and Its Applications

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Ion transport characteristics in nanofiltration membranes: measurements and mechanisms

Ion transport characteristics during nanofiltration (NF) were investigated by measuring effective osmotic pressure and diffusivity experimentally. Effective osmotic pressure and diffusivity were measured through lab-scale transport and diffusion tests. First, it was shown that the water flux across NF membranes decreased dramatically with increasing ionic strength because of the noticeable increase in effective osmotic pressure. Second, the results from transport experiments showed that the ion selectivity values, which were derived from the thermodynamic model, decreased with increasing ionic strength. Third, by analysing the data of measured osmotic pressure and diffusivity, it was demonstrated that the former and the latter increased and decreased, respectively, as ionic strength increased. The experimentally determined osmotic pressure across NF membranes was much lower than that calculated theoretically. At best, around 5% or less of the theoretical osmotic pressure was obtained under the experimental conditions investigated. The effective osmotic pressure and ion rejection decreased in the presence of nano-colloids. The influence of nano-colloids on ionic transport was found to be dependent on the concentration and size of the nano-colloids. Therefore, ion transport characteristics across NF membranes can be determined practically by measuring effective osmotic pressure and diffusivity as these reflect both feed water and membrane propertiesopen6

Variations in backwash efficiency during colloidal filtration of hollow-fiber microfiltration membranes

A series of filtration experiments was performed systematically to investigate physical and chemical factors affecting the efficiency of backwashing during microfiltration of colloidal suspensions. In this study, all experiments were conducted in dead-end filtration mode utilizing an outside-in, hollow-fiber module with a nominal pore size of 0.1 mu m. Silica particles (mean diameter = 0.14 mu m) were used as model colloids. Using a flux decline model based on the Happel's cell for the hydraulic resistance of the particle layer, the cake structure was determined from experimental fouling data and then correlated to backwash efficiency. Modeling of experimental data revealed no noticeable changes in cake layer structure when feed particle concentration and operating pressure increased. Specifically, the packing density of the cake layer (1-cake porosity) in the cake layer ranged from 0.66 to 0.67, which corresponds well to random packing density. However, the particle packing density increased drastically with ionic strength. The results of backwashing experiments demonstrated that the efficiency of backwashing decreased significantly with increasing solution ionic strength, while backwash efficiency did not vary when particle concentration and operating pressure increased. This finding suggests that backwash efficiency is closely related to the structure of the cake layer formed during particle filtration. More densely packed cake layers were formed under high ionic strength, and consequently less flux was recovered per given backwash volume during backwashingclose182

Towards Sequence-Level Training for Visual Tracking

Despite the extensive adoption of machine learning on the task of visual object tracking, recent learning-based approaches have largely overlooked the fact that visual tracking is a sequence-level task in its nature; they rely heavily on frame-level training, which inevitably induces inconsistency between training and testing in terms of both data distributions and task objectives. This work introduces a sequence-level training strategy for visual tracking based on reinforcement learning and discusses how a sequence-level design of data sampling, learning objectives, and data augmentation can improve the accuracy and robustness of tracking algorithms. Our experiments on standard benchmarks including LaSOT, TrackingNet, and GOT-10k demonstrate that four representative tracking models, SiamRPN++, SiamAttn, TransT, and TrDiMP, consistently improve by incorporating the proposed methods in training without modifying architectures.1

A Disposable Bod Microsensor Using A Polymer Substrate

A disposable microbial sensor was designed, fabricated and tested for standard BOD (Biochemical Oxygen Demand) measurements. A transparent Cyclic Olefin Copolymer (COC) substrate was used for sensor fabrication. Standard lithographic procedures in addition to techniques like screen printing and electroplating were used to fabricate the sensor. A layer of a microbial strain of Trichosporon Cutaneum was immobilized over one pair of sensor electrodes while the other was used as a reference. Depending on the respiratory activities of the microbial strain in different samples, the BOD values of the samples could be measured in terms of difference between the output signals. The sensor layer was enclosed by an injection-molded passive microfluidic channel on the top. The BOD sensor was calibrated and tested with standard BOD solutions and samples obtained from a wastewater reclamation facility. Good correlation with chemically determined BOD5 values was obtained with fast response time. Advantages of the BOD microsensor include (a) fast BOD measurement (b) disposability from a low cost, chemically inert polymer substrate (c) flow-through sample injection scheme and (d) possible future integration of on-chip optics. © 2004 IEEE

Micro-Current Stimulation Suppresses Inflammatory Responses in Peptidoglycan-Treated Raw 264.7 Macrophages and Propionibacterium acnes-Induced Skin Inflammation via TLR2/NF-κB Signaling Pathway

Acne is a common inflammatory disorder of the human skin and a multifactorial disease caused by the sebaceous gland and Propionibacterium acnes (P. acnes). This study aimed to evaluate the anti-inflammatory effect of micro-current stimulation (MC) on peptidoglycan (PGN)-treated raw 264.7 macrophages and P. acnes-induced skin inflammation. To specify the intensity with anti-inflammatory effects, nitric oxide (NO) production was compared according to various levels of MC. As the lowest NO production was shown at an intensity of 50 μA, subsequent experiments used this intensity. The changes of expression of the proteins related to TLR2/NF-κB signaling were examined by immunoblotting. Also, immunofluorescence analysis was performed for observing NF-κB p65 localization. All of the expression levels of proteins regarding TLR2/NF−κB signaling were decreased by the application of MC. Moreover, the application of MC to PGN−treated raw 264.7 cells showed a significant decrease in the amount of nuclear p65−protein. In the case of animal models with P. acnes−induced skin inflammation, various pro−inflammatory cytokines and mediators significantly decreased in MC−applied mice. In particular, the concentration of IL−1β in serum decreased, and the area of acne lesions, decreased from the histological analysis. We suggest for the first time that MC can be a novel treatment for acne

Enhanced performance of a direct contact membrane distillation (DCMD) system with a Ti/MgF2 solar absorber under actual weather environments

In this study, we report on a solar membrane distillation (MD) system with a 5-stack Ti/MgF2 solar absorber adapted as a heat source under actual weather conditions. The 5-stack Ti/MgF2 solar absorber showed light absorption of 85% over the wavelength range from 0.3 to 2.5 mu m. This consequently induced greater heat and a two-fold greater water heating capability up to 80 degrees C for water in a closed water tank without insulation under a 1-sun illumination. The enhanced solar absorption of the Ti/MgF2 solar absorber showed a 12% improvement in permeate flux of the integrated MD system compared with a system without a solar absorber. Under actual weather conditions, the solar DCMD system with the Ti/MgF2 solar absorber successfully produced distillate water in the range of 0.51-4.78 L/m(2).day depending on weather conditions. Despite unfavorable solar irradiance conditions in autumn, the integrated DCMD system with the Ti/MgF2 solar absorber proved superior to a conventional commercial evacuated-tube solar collector in terms of daily production of distillate water and solar energy requirements for certain amounts of distillate