431 research outputs found
Efficient Privacy Preserving Viola-Jones Type Object Detection via Random Base Image Representation
A cloud server spent a lot of time, energy and money to train a Viola-Jones
type object detector with high accuracy. Clients can upload their photos to the
cloud server to find objects. However, the client does not want the leakage of
the content of his/her photos. In the meanwhile, the cloud server is also
reluctant to leak any parameters of the trained object detectors. 10 years ago,
Avidan & Butman introduced Blind Vision, which is a method for securely
evaluating a Viola-Jones type object detector. Blind Vision uses standard
cryptographic tools and is painfully slow to compute, taking a couple of hours
to scan a single image. The purpose of this work is to explore an efficient
method that can speed up the process. We propose the Random Base Image (RBI)
Representation. The original image is divided into random base images. Only the
base images are submitted randomly to the cloud server. Thus, the content of
the image can not be leaked. In the meanwhile, a random vector and the secure
Millionaire protocol are leveraged to protect the parameters of the trained
object detector. The RBI makes the integral-image enable again for the great
acceleration. The experimental results reveal that our method can retain the
detection accuracy of that of the plain vision algorithm and is significantly
faster than the traditional blind vision, with only a very low probability of
the information leakage theoretically.Comment: 6 pages, 3 figures, To appear in the proceedings of the IEEE
International Conference on Multimedia and Expo (ICME), Jul 10, 2017 - Jul
14, 2017, Hong Kong, Hong Kon
DoubleAUG: Single-domain Generalized Object Detector in Urban via Color Perturbation and Dual-style Memory
Object detection in urban scenarios is crucial for autonomous driving in
intelligent traffic systems. However, unlike conventional object detection
tasks, urban-scene images vary greatly in style. For example, images taken on
sunny days differ significantly from those taken on rainy days. Therefore,
models trained on sunny day images may not generalize well to rainy day images.
In this paper, we aim to solve the single-domain generalizable object detection
task in urban scenarios, meaning that a model trained on images from one
weather condition should be able to perform well on images from any other
weather conditions. To address this challenge, we propose a novel Double
AUGmentation (DoubleAUG) method that includes image- and feature-level
augmentation schemes. In the image-level augmentation, we consider the
variation in color information across different weather conditions and propose
a Color Perturbation (CP) method that randomly exchanges the RGB channels to
generate various images. In the feature-level augmentation, we propose to
utilize a Dual-Style Memory (DSM) to explore the diverse style information on
the entire dataset, further enhancing the model's generalization capability.
Extensive experiments demonstrate that our proposed method outperforms
state-of-the-art methods. Furthermore, ablation studies confirm the
effectiveness of each module in our proposed method. Moreover, our method is
plug-and-play and can be integrated into existing methods to further improve
model performance.Comment: Accepted by ACM Transactions on Multimedia Computing, Communications,
and Application
Predicting Aesthetic Score Distribution through Cumulative Jensen-Shannon Divergence
Aesthetic quality prediction is a challenging task in the computer vision
community because of the complex interplay with semantic contents and
photographic technologies. Recent studies on the powerful deep learning based
aesthetic quality assessment usually use a binary high-low label or a numerical
score to represent the aesthetic quality. However the scalar representation
cannot describe well the underlying varieties of the human perception of
aesthetics. In this work, we propose to predict the aesthetic score
distribution (i.e., a score distribution vector of the ordinal basic human
ratings) using Deep Convolutional Neural Network (DCNN). Conventional DCNNs
which aim to minimize the difference between the predicted scalar numbers or
vectors and the ground truth cannot be directly used for the ordinal basic
rating distribution. Thus, a novel CNN based on the Cumulative distribution
with Jensen-Shannon divergence (CJS-CNN) is presented to predict the aesthetic
score distribution of human ratings, with a new reliability-sensitive learning
method based on the kurtosis of the score distribution, which eliminates the
requirement of the original full data of human ratings (without normalization).
Experimental results on large scale aesthetic dataset demonstrate the
effectiveness of our introduced CJS-CNN in this task.Comment: AAAI Conference on Artificial Intelligence (AAAI), New Orleans,
Louisiana, USA. 2-7 Feb. 201
Online Cooperative Promotion and Cost Sharing Policy under Supply Chain Competition
This paper studies online cooperative promotion and cost sharing decisions in competing supply chains. We consider a model of one B2C e-commerce platform and two supply chains each consisting of a supplier and an online retailer. The problem is studied using a multistage game. Firstly, the e-commerce platform carries out the cooperative promotion and sets the magnitude of markdown (the value of e-coupon). Secondly, each retailer and his supplier determine the fraction of promotional cost sharing when they have different bargaining power. Lastly, the retailers decide whether to participate in the cooperative promotion campaign. We show that the retailers are likely to participate in the promotion if consumers become more price-sensitive. However, it does not imply that the retailers can benefit from the price promotion; the promotion decision game resembles the classical prisoner’s dilemma game. The retailers and suppliers can benefit from the cooperative promotion by designing an appropriate cost sharing contract. For a supply chain, the bargaining power between supplier and retailer, consumer price sensitivity, and competition intensity affect the fraction of the promotional cost sharing. We also find that equilibrium value of e-coupon set by the e-commerce platform is not optimal for all the parties
Optomechanically-induced transparency in parity-time-symmetric microresonators
Optomechanically-induced transparency (OMIT) and the associated slowing of light provide the basis for storing photons in nanoscale devices. Here we study OMIT in parity-time (PT)-symmetric microresonators with a tunable gain-to-loss ratio. This system features a sideband-reversed, non-amplifying transparency, i.e., an inverted-OMIT. When the gain-to-loss ratio is varied, the system exhibits a transition from a PT-symmetric phase to a broken-PT-symmetric phase. This PT-phase transition results in the reversal of the pump and gain dependence of the transmission rates. Moreover, we show that by tuning the pump power at a fixed gain-to-loss ratio, or the gain-to-loss ratio at a fixed pump power, one can switch from slow to fast light and vice versa. These findings provide new tools for controlling light propagation using nanofabricated phononic devices
Observation of topological flat bands in the kagome semiconductor NbCl
The destructive interference of wavefunctions in a kagome lattice can give
rise to topological flat bands (TFBs) with a highly degenerate state of
electrons. Recently, TFBs have been observed in several kagome metals,
including FeSn, FeSn, CoSn, and YMnSn. Nonetheless, kagome
materials that are both exfoliable and semiconducting are lacking, which
seriously hinders their device applications. Herein, we show that NbCl,
which hosts a breathing kagome lattice, is gapped out because of the absence of
inversion symmetry, while the TFBs survive because of the protection of the
mirror reflection symmetry. By angle-resolved photoemission spectroscopy
measurements and first-principles calculations, we directly observe the TFB and
a moderate band gap in NbCl. By mechanical exfoliation, we successfully
obtain monolayers of NbCl and confirm that they are stable under
ambient conditions. In addition, our calculations show that monolayers of
NbCl have a magnetic ground state, thus providing opportunities to
study the interplay between geometry, topology, and magnetism.Comment: 6 pages, 4 figure
Tunable Magnetocaloric Effect in Ni-Mn-Ga Microwires
Abstract Magnetic refrigeration is of great interest due to its high energy efficiency, environmental friendliness and low cost. However, undesired hysteresis losses, concentrated working temperature interval (WTI) and poor mechanical stability are vital drawbacks that hinder its practical application. Off-stoichiometric Ni-Mn-Ga Heusler alloys are capable of giant magnetocaloric effect (MCE) and tunable transformation temperatures. Here, by creating Ni-Mn-Ga microwires with diameter of 35–80 μm using a melt-extraction technique, negligible hysteresis and relatively good mechanical stability are found due to the high specific surface area (SSA) that reduces incompatibility between neighboring grains. The high SSA also favors the element evaporation at high temperatures so that the transformation temperatures can be feasibly adjusted. Tunable magnetocaloric effect owing to different magneto-structural coupling states is realized by (i) composition design and subsequent tuning, which adjusts the temperature difference between the martensite transformation (MT) and the magnetic transition, and (ii) creation of gradient composition distribution state, which manipulates the MT range. Magnetic entropy change ΔS m ~−18.5 J kg−1 K−1 with relatively concentrated WTI and WTI up to ~60 K with net refrigeration capacity ~240 J kg−1 at 50 kOe are demonstrated in the present Ni-Mn-Ga microwires. This criterion is also applicable for other small-sized materials
Distribution, characterization, and induction of CD8+ regulatory T cells and IL-17-producing CD8+ T cells in nasopharyngeal carcinoma
<p>Abstract</p> <p>Background</p> <p>CD8<sup>+ </sup>effector cells often have an antitumor function in patients with cancer. However, CD8<sup>+</sup>Foxp3<sup>+ </sup>regulatory T cells (Tcregs) and interleukin (IL)-17-producing CD8<sup>+ </sup>T cells (Tc17 cells) also derive from the CD8<sup>+ </sup>T cell lineage. Their role in the antitumor response remains largely unknown. In the present study, we aimed to investigate the distribution, characterization, and generation of CD8<sup>+ </sup>Tcregs and Tc17 cells in NPC patients.</p> <p>Methods</p> <p>Peripheral blood and tumor biopsy tissues from 21 newly diagnosed patients with nasopharyngeal carcinoma (NPC) were collected, along with peripheral blood from 21 healthy donors. The biological characteristics of Tcregs and Tc17 cells from blood and tumor tissues were examined by intracellular staining, tetramer staining and fluorescence-activated cell sorting (FACS) analysis. The suppressive function of Tcregs was investigated using a proliferation assay that involved co-culture of sorted CD8<sup>+</sup>CD25<sup>+ </sup>T cells with naïve CD4<sup>+ </sup>T cells <it>in vitro</it>.</p> <p>Results</p> <p>We observed an increased prevalence of Tcregs and Tc17 cells among tumor-infiltrating lymphocytes (TILs) and different distribution among peripheral blood mononuclear cells (PBMCs) in NPC patients. Cytokine profiles showed that the Tcregs expressed a high level of IL-10 and low level of transforming growth factor β, whereas Tc17 cells expressed a high level of tumor necrosis factor α. Interestingly, both subsets expressed a high level of interferon γ in TILs, and the Tcregs suppressed naïve CD4<sup>+ </sup>T cell proliferation by a cell contact-dependent mechanism <it>in vitro</it>. Moreover, we demonstrated the existence of Epstein-Barr virus latent membrane protein (LMP) 1 and LMP2 antigen-specific Tcregs in NPC.</p> <p>Conclusions</p> <p>Our data provide new insights into the composition and function of CD8<sup>+ </sup>T-cell subsets in NPC, which may have an important influence on NPC immunotherapy.</p
Functional proteomic analysis reveals the involvement of KIAA1199 in breast cancer growth, motility and invasiveness.
BACKGROUND: KIAA1199 is a recently identified novel gene that is up-regulated in human cancer with poor survival. Our proteomic study on signaling polarity in chemotactic cells revealed KIAA1199 as a novel protein target that may be involved in cellular chemotaxis and motility. In the present study, we examined the functional significance of KIAA1199 expression in breast cancer growth, motility and invasiveness.
METHODS: We validated the previous microarray observation by tissue microarray immunohistochemistry using a TMA slide containing 12 breast tumor tissue cores and 12 corresponding normal tissues. We performed the shRNA-mediated knockdown of KIAA1199 in MDA-MB-231 and HS578T cells to study the role of this protein in cell proliferation, migration and apoptosis in vitro. We studied the effects of KIAA1199 knockdown in vivo in two groups of mice (n = 5). We carried out the SILAC LC-MS/MS based proteomic studies on the involvement of KIAA1199 in breast cancer.
RESULTS: KIAA1199 mRNA and protein was significantly overexpressed in breast tumor specimens and cell lines as compared with non-neoplastic breast tissues from large-scale microarray and studies of breast cancer cell lines and tumors. To gain deeper insights into the novel role of KIAA1199 in breast cancer, we modulated KIAA1199 expression using shRNA-mediated knockdown in two breast cancer cell lines (MDA-MB-231 and HS578T), expressing higher levels of KIAA1199. The KIAA1199 knockdown cells showed reduced motility and cell proliferation in vitro. Moreover, when the knockdown cells were injected into the mammary fat pads of female athymic nude mice, there was a significant decrease in tumor incidence and growth. In addition, quantitative proteomic analysis revealed that knockdown of KIAA1199 in breast cancer (MDA-MB-231) cells affected a broad range of cellular functions including apoptosis, metabolism and cell motility.
CONCLUSIONS: Our findings indicate that KIAA1199 may play an important role in breast tumor growth and invasiveness, and that it may represent a novel target for biomarker development and a novel therapeutic target for breast cancer
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