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A modified 2-D reverse-time migration algorithm in the energy flow domain, called EF-RTM, is proposed for short impulse borehole radar (BHR) imaging. The key of the approach is based on Poynting’s theorem, which allows decomposition of the energy flux density (EFD) derived from the source and receiver wave fields in different wave-propagation directions. Then, imaging conditions, for example, zero-lag cross correlation (prestack migration) and zero-time imaging principle (poststack migration), are applied to the decomposed EFD-field components to obtain the migrated sections. The characteristics of the resulting images can be optionally combined or separately used for better BHR data imaging, interpretation, and analysis. In this paper, the EF-RTM algorithm is validated by numerical modeling and real field data and compared with the conventional RTM algorithm. All the results show that this new EF-RTM method is superior to the conventional RTM method: it inherits the high precision of RTM with additional imaging advantages, such as natural wave-field decomposition in different directions, improved migrated cross-range resolution, a better focus of the target’s shape, and migration noise reduction.

Recently multi-party quantum private comparison (MQPC) has attracted more and more attentions in the research of quantum cryptography. In our paper, a new MQPC protocol has been proposed by encoding the compared secrets on the phase of n-level single photons. From the proposed protocol, a generic model named circle model can be summarized. With the help of a semi-honest third party (TP), it can be proved that our protocol is immune to the outside attack and dishonest participants’ (including TP) attack.

Optical force, which is known as a powerful effect of the light on all objects and is too weak to be perceived directly. While the momentum transfer between light and matter can be greatly improved at the nanometer scale. In this paper, we mainly designed an asymmetric deep subwavelength metal nanostructure to generate a strong optical field gradient force by utilizing the resonant interaction between light and nanostructures as well as coupled excitation of surface plasmon, which can promote the movement of the nanoparticles. After simulating and optimizing, we learned that the intensity of optical field excited by the stepped trapezoidal nanostructure we designed in this paper is 140 times higher than that of incident light. At last, we fabricated and tested the sample of the designed nanostructures with the method of electron-beam lithography (EBL), and get the data of the speckle distribution curve and scattering curve of the sample. We discovered that in the wavelength range from 300 nm to 1100 nm, the sample will be excited to a strong plasma. It can be inferred that the devices cascaded by such structural units can accelerate and emit a large number of nanoparticles to generate considerable thrust, which has a great application prospects for the precise positioning of spacecraft.

Chlamydia trachomatis (C. trachomatis) is a major etiological agent of sexually transmitted infection. Some stressing conditions can result in persistent chlamydial infection, which is thought to be associated with severe complications including ectopic pregnancy and tubal factor infertility. Long noncoding RNAs (lncRNAs) have been identified as key modulators in many biological processes. Nevertheless, the role of lncRNAs in persistent chlamydial infection is still unclear. In this study, we used lncRNA and mRNA microarray to identify the global lncRNAs and mRNAs expression in penicillin-induced persistent chlamydial infection in HeLa cells as well as the control group (HeLa cells without C. trachomatis infection). Among 1005 differentially expressed lncRNAs, 585 lncRNAs were upregulated and 420 downregulated in persistent chlamydial infection, while 410 mRNAs were identified to express differentially, of which 113 mRNAs were upregulated and 297 downregulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis with differentially expressed genes were performed. We then constructed the lncRNA-miRNA-mRNA competing endogenous RNAs (ceRNAs) network. Four mRNAs were validated to be changed by quantitative real-time PCR which were correlated with the microarray result. Integration of protein-protein interaction network was constructed and hub genes were identified. These findings provide a new perspective on the molecular mechanisms of penicillin-induced persistent chlamydial infection.

Chlamydia trachomatis is an obligate intracellular bacterium that causes multiple diseases involving the eyes, gastrointestinal tract, and genitourinary system. Previous studies have identified that in acute chlamydial infection, C. trachomatis requires Akt pathway phosphorylation and Rab14-positive vesicles to transmit essential lipids from the Golgi apparatus in survival and replication. However, the roles that Akt phosphorylation and Rab14 play in persistent chlamydial infection remain unclear. Here, we discovered that the level of Akt phosphorylation was lower in persistent chlamydial infection, and positively correlated with the effect of activating the development of Chlamydia but did not change the infectivity and 16s rRNA gene expression. Rab14 was found to exert a limited effect on persistent infection. Akt phosphorylation might regulate Chlamydia development and Chlamydia-induced Golgi fragmentation in persistent infection without involving Rab14. Our results provide a new insight regarding the potential of synergistic repressive effects of an Akt inhibitor with antibiotics in the treatment of persistent chlamydial infection induced by penicillin.

Background GLS-010, a novel engineered fully human immunoglobin G4 monoclonal antibody, can specially block the PD-1/PD-L1/2 axis and reactivate the antitumor immunity. Aim This phase Ia/Ib study was carried out to evaluate the safety, recommended phase II dose (R2PD), and primary antitumor effects of GLS-010 in patients with advanced, refractory lymphoma and solid tumors. Methods In phase Ia study, patients with refractory solid tumors and lymphoma enrolled and received GLS-010 at a dose of 1, 4, or 10 mg/kg Q2W; 240 mg Q3W or Q2W. The primary objective was to assess the dose-limiting toxicity (DLT). In phase Ib study, doses were expanded in 9 specific tumors to ensure the R2PD and explore the efficacy. Tumor mutation burden level and PD-L1 expression were also assessed with whole-exome sequencing and immunohistochemistry (SP263), respectively. Results Up to April 18, 2020, a total of 289 patients (n = 24, phase Ia; n = 265, phase Ib) were enrolled. DLT was not observed in phase Ia part. The T1/2, CLss, and Vd were similar among all dose groups and different tumors. The most common treatment-emergent adverse events (TEAEs) were anemia, leukopenia, elevated alanine aminotransaminase/asparate aminotransferase (ALT/AST), and elevated bilirubin. And hypothyroidism was the most common immune-related adverse event (irAE). The incidence of grade ≥3 TEAE was 39.8%, while grade ≥3 irAE was only 4.5%. Based on safety studies, pharmacokinetics/pharmacodynamics, and preclinical data, 240-mg Q2W was recommended as the expansion dose. The overall objective response rate was 23.6%, with 10 patients achieving complete response. Patients with a high PD-L1 expression level (31.3% Versus. 13.7%, p = 0.012) or t-issue tumor mutation burden level (31.3% Versus. 5.6%, p = 0.009) showed a significantly better response. Conclusion GLS-010 showed acceptable safety profile and favorable clinical response. The dose of 240 mg Q2W was an optimal recommended dose as monotherapy.

Background: Meningioma is one of the most common tumors of central nervous system. Although genetic alterations have been linked to elevated risk of malignancy for meningioma patients, the incongruence between clinical outcomes and WHO grade classification still exist. Therefore, large-scale genome-wide expression profiles identifying reliable biomarkers remains incompletely investigated. Methods: In order to identify genes related to invasion and metastasis process in meningiomas, genome-wide profiles in 145 meningioma patients were identified using microarray datasets GSE12530, GSE16581 and GSE43290 from the Gene Expression Synthesis (GEO) database based on differential tissues expression. Protein-protein interaction (PPI) network were constructed and functional annotations of DEGs were evaluated using R software. In addition, differential expression and prognostic value of CLU on meningioma was evaluated using immunohistochemistry in WHO grade II-III meningioma from AHYMUN, a real-world cohort. Results: A total of 58 DEGs were significantly associated with malignant behaviours of meningioma. Next, CLU were identified as hub gene in the PPI network, showing markedly prognostic implications in 67 meningioma patients. Expression level of CLU significantly climbed with elevated WHO risk classification. Interestingly, 40 genes were screened according to differential CLU expression. Additionally, significant high expression level of CLU were found in meningiomas tissue than normal tissues, predicting significant poor prognosis for 100 meningiomas patients from AHYMUN cohort. Conclusion: In conclusion, this study first reveals novel role of CLU using genome-wide expression profiles in high-risk WHO grade of meningioma and significant prognostic value based on large-scale cohorts. This work laid the foundation for the targeted molecular therapies and provided new insights into the treatment and prognostic srategies of meningiomas.

Background Chronic actinic dermatitis (CAD) is a recurrent photosensitive disease occurs predominantly in elderly men on sun-exposed areas, which seriously affect the patient's life quality. The etiology of CAD remains unknown. Methods Sixty-six CAD patients, 66 atopic dermatitis (AD) patients, and 46 healthy people were enrolled into this study. Patient-level data were obtained from the electronic medical record and laboratory databases. We also obtained 29 tissue samples including 16 lichenoid lesions, 7 minimal erythematous dose (MED) analysis induced lesions, and 6 normal skin samples. Histopathologic and immunohistochemical analysis were performed. Results In the clinical characteristics, albumin was lower and uric acid was higher significantly in patients diagnosed as CAD. The infection rate of CAD patient after skin biopsy was considerably high (23.3%). The serum allergen test was prone to be negative in CAD patients. Lymphocytes were the dominate infiltrating cells in early and late CAD lesions, while more CD4+, CD8+, CD69+, and CD103 + cells were found in the late lesions. There is no difference in CD4+/CD8 + ratio and CD69+/CD103 + ratio among groups. More mast cells were observed in the early-stage lesions, and more dendritic cell was observed in the late-stage lesions. Conclusions CAD patients have certain oxidative stress and are prone to be infected after skin biopsy. Serum allergen detection is of little significance for CAD diagnosis. Mast cells may be involved in the early process of CAD, while dendritic cells and tissue-resident memory T cell (TRM) may be related to the chronic process of the disease.

Cloud computing is a promising paradigm to provide flexible and reliable services. Nevertheless, concern and anxiety about data security and tenants’ privacy are still a major barrier for the popularity of cloud computing. Oblivious transfer (OT) is a cryptographic primitive that enables a client to selectively retrieve data in a privacy-preserving manner. It can be used to construct high-level protocols enabling applications in the cloud-computing paradigm. Technically, it has been proven that OT protocols can be constructed using a CPA-secure public-key encryption scheme. Along these lines, Peikert et al. formulated a dual-mode cryptosystem on which they constructed a single-bit OT scheme. Obviously, it has deficiencies in performance, which makes it unqualified for use in cloud-computing scenarios. This paper aims at providing an efficient multi-bit OT scheme for secure cloud applications. We first propose a multi-bit dual-mode cryptosystem based on the learning with errors (LWE) problem. Based...

In this paper, we present an offline arbitrated quantum blind dual-signature protocol by using four-particle entangled Greenberger-Horne-Zeilinger(GHZ) states. By using the special relationship of four-particle GHZ states, we can not only support the security of quantum signature, but also guarantee the anonymity of the message owner. In our protocol, the authority of the arbitrator has been reduced, i.e., he will not help the receiver verify the signature in the verification. Compared with the previous quantum blind signature protocols, the presented arbitrator is offline. Finally, the security analysis and discussion are proposed.

In opportunistic networks, most existing buffer management policies including scheduling and passive dropping policies are mainly for routing protocols. In this paper, we proposed a Utility-based Buffer Management strategy (UBM) for data dissemination in op- portunistic networks. In UBM, we first design a method of computing the utility values of caching messages according to the interest of nodes and the delivery probability of messages, and then propose an overall buffer management policy based on the utility. UBM driven by receivers completely implements not only cach- ing policies, passive and proactive dropping policies, but also scheduling policies of send- ers. Simulation results show that, compared with some classical dropping strategies, UBM can obtain higher delivery ratio and lower delay latency by using smaller network cost.

At FOCS2011 Brakerski and Vaikuntanathan proposed a single-server LWE-based private information retrieval (abbreviated as PIR) protocol with a security reduction to hard standard lattice problems and nearly optimal communication complexity. However, Brakerski just described a generic PIR protocol that utilized a somewhat homomorphic encryption and an arbitrary symmetric encryption as building blocks, he did not instantiate the generic construction. In this work, we first modify Brakerski's construction without the evaluating key and construct a new PIR model. Moreover, we instantiate our new model via matrix FHE first proposed by Ryo et al. at PKC2015 and vector symmetric encryption scheme proposed in this work as building block. Then we optimize the Response operations and several other aspects of the scheme.

The rapid development of the Internet of Things has made the issue of privacy protection even more concerning. Privacy protection has affected the large-scale application of the Internet of Things. Fully Homomorphic Encryption (FHE) is a newly emerging public key encryption scheme, which can be used to prevent information leakage. It allows performing arbitrary algebraic operations on data which are encrypted, such that the operation performed on the ciphertext is directly transformed into the corresponding plaintext. Recently, overwhelming majority of FHE schemes are confined to single-bit encryption, whereas how to achieve a multibit FHE scheme is still an open problem. This problem is partially (rather than fully) solved by Hiromasa-Abe-Okamoto (PKC′15), who proposed a packed message FHE scheme which only supports decryption in a bit-by-bit manner. Followed by that, Li-Ma-Morais-Du (Inscrypt′16) proposed a multibit FHE scheme which can decrypt the ciphertext at one time, but their scheme is based on dual LWE assumption. Armed with the abovementioned two schemes, in this paper, we propose an efficient packed message FHE that supports the decryption in two ways: single-bit decryption and one-time decryption.

In this report a novel UWB directional antenna for a single borehole radar (BHR) is presented. The antenna consists of three parts: a dipole antenna with the discrete resistive loading, a ferrite groove and a metal back cavity. Feeding into the antenna by a first order Gaussian pulse with the peak value pulse width is 3 ns in a limestone media. The time domain waveforms can indicate that the peak value of the trailing signal is small and the duration is short; the −3 dB beamwidth of the normalized energy pattern in the H-plane is from 105° to 255 s° and the front-to-back ratio is 8.9 dB. Meanwhile, the normalized peak pattern of the directional antenna by experiment agree with the simulation, the front-to-back ratio of which is 8.5 dB. And it is thus clear that the directional antenna is suitable for a single borehole radar in the geological environment of limestone.

Identity-based proxy re-encryption ( $ \mathsf {IBPRE}$ ) is a powerful cryptographic tool for various applications, such as access control system, secure data sharing, and secure e-mail forwarding. Most of the existing efficient $ \mathsf {IBPRE}$ schemes are based on the Diffie–Hellman assumption, and they only focus on the single-hop construction. Based on the work of Chandran et al. ’s lattice-based proxy re-encryption ( $ \mathsf {PRE}$ ) scheme (PKC’14) and Yamada’s lattice-based identity-based encryption ( $ \mathsf {IBE}$ ) scheme (EUROCRYPT’16), in this paper, we first show the possibility of assembling lattice-based $ \mathsf {IBE}$ into lattice-based $ \mathsf {PRE}$ . Then, we present the construction of a new efficient single-hop homomorphic $ \mathsf {IBPRE}$ from learning with errors ( $ \mathsf {LWE}\text{s}$ ) via key homomorphic computation. Furthermore, using branching program ( $ \mathsf {BP}$ ), we obtain an efficient multi-hop $ \mathsf {IBPRE}$ scheme. To the best of our knowledge, our scheme is the first multi-hop homomorphic $ \mathsf {IBPRE}$ scheme via $ \mathsf {BP}$ . Our scheme supports homomorphic evaluation and is proved secure under the decisional $ \mathsf {LWE}$ assumption.

Background ARID1B, which exists as a mutually exclusive isoform with ARID1A in the SWI/SNF chromatin remodeling complex, has been recently identified as a major mutant gene in a wide variety of cancers. The present study aimed to determine the association between ARID1B expression and outcomes, as well as the benefit from adjuvant chemotherapy in patients with bladder cancer. Methods Tissue microarrays of 143 consecutively recruited patients with bladder cancer from our center were created. Immunohistochemistry was performed to assess the expression of ARID1B and its association with outcomes. Clinicopathological factors were also evaluated. Results ARID1B expression was significantly associated with tumor size (P=0.015), T stage (P=0.027), lymph node status (P=0.030), TNM stage (P=0.040), overall survival (P

A borehole radar (BHR) prototype system was developed for the exploration of complicated oil and gas reservoirs. To verify the performance of the system, single-hole reflection imaging experiments were carried out in an abandoned limestone mine. In the physical experiments, the cliff wall and a metal plate were selected as the imaging targets to evaluate the detection performance of the prototype system. The average filter method was used to remove the background noise, then the frequency–wave number (F-K) imaging algorithm was adopted for radar imaging. The unknown fractures surrounding the borehole produced complex reflections that were not beneficial to effectively extract the target echo when the down-hole sensor was shifted along the borehole. However, by fixing the down-hole sensor and shifting the target, the detection range of the radar system extended up to about 10 m in the limestone formation. A 2-D finite-difference time-domain (FDTD) modeling method was also implemented to simulate the experimental procedure, and demonstrated that the prototype system can provide enough accuracy to predict the echo signal characteristics and reproduce the radar response in the formation. The combination of field experiment, theoretical analysis, and numerical simulation not only objectively validated the fundamental performance of the radar prototype, but also generated some new concepts for further improvement on the radar system design.

In cyberspace security, the privacy in location-based services (LBSs) becomes more critical. In previous solutions, a trusted third party (TTP) was usually employed to provide disturbance or obfuscation, but it may become the single point of failure or service bottleneck. In order to cope with this drawback, we focus on another important class, establishing anonymous group through short-range communication to achieve k-anonymity with collaborative users. Along with the analysis of existing algorithms, we found users in the group must share the same maximum anonymity degree, and they could not ease the process of preservation in a lower one. To cope with this problem, we proposed a random-QBE algorithm to put up with personalized anonymity in user collaboration algorithms, and this algorithm could preserve both query privacy and location privacy. Then we studied the attacks from passive and active adversaries and used entropy to measure user's privacy level. Finally, experimental evaluations further verify its effectiveness and efficiency.

In view of research on fully homomorphic encryption scheme proposed by Zvika Brakerski in 2012, we find it is not much efficient, because it requests that $$q/B \ge (O(nlogq))^{L+O(1)}$$ , and can encrypt only one message at a time. In this paper, we have proved that STP-binary-LWE is hard when LWE is hard, and have modified the fully homomorphic encryption scheme based on STP-Binary-LWE so that it only requests $$q/B \ge (O(nlog(logn)))^{L+O(1)}$$ . It is within the reach of the scheme to encrypt several messages at a time and give consideration to both security and efficiency in the hierarchical encryption systems.

Information fusion is a very important technology which can use multisensor network data to get a better performance than single one; therefore, it is widely used in the filed of target recognition, target tracking, automatic control, decision making and so on. However, because of noise and interference, sometimes the sensors may obtain erroneous, inaccurate or heterogeneous data, which will produce the conflict information among different sensors and get the wrong result after information fusion. In this paper, based on the Dempster---Shafer (D---S) theory, we introduce how to set up the model of multisensor network information fusion. And then, we discuss the problem of conflict information fusion in the framework of evidence and several improved methods are introduced. Finally, based on Mahalanobis distance, an improved solution method is presented. The numerical simulation results prove that this new improved method can get the same result as traditional methods, beyond which it can make a reasonable decision with high conflict information. Therefore, this new improved method can be used in the filed of high noise and interference.

Information entropy features are often used for radiation source signal recognition, but due to the information entropy is very sensitive to noise, so this method has greater recognition rate changes with the SNR. This paper putting forward a viable recognition based on Entropy and cloud model. using cloud model to extract secondary features of signals, build radiation source signal’s entropy and cloud feature vector. The method uses cloud model description and processing interval fuzzy and observation noise data, better solve the low SNR cases of radiation source signal feature extraction problem. At the same time, putting forward the similar cloud classification recognition algorithm based on cloud model. The simulation results show that Entropy and cloud model has better recognition effect under low SNR, which can improve the signals’ recognition rate under low SNR.

Many supply chain finance problems can be fundamentally solved by using blockchain. The current technical challenge of applying blockchain in supply chain finance is the lack of systematic privacy protection architecture. Based on the architecture of Julongchain, through the nonlinear principal component analysis in private data feature extraction, this paper proposed a new type of privacy protection architecture based on specific supply chain financial system. This privacy protection solution split privacy data by decision machine, then mixed data using mixed mechanism, finally determined the characteristic weight of privacy data by applying the decentralized decision institution.

Background: GLS-010 is a novel fully human anti-PD-1 mAb developed by the OMT transgenic rat platform. In Phase 1a study, GLS-010 exhibited good tolerance and 240mg (Q2W) was selected. Phase 1b study was conducted to evaluate the safety,anti-tumor activity and explore biomarkers of GLS-010 in pts with advanced solid tumors or lymphomas. Methods: All pts enrolled received GLS-010 240 mg every 2 weeks. Tumor response was assessed by RECIST 1.1 every 8 weeks. Adverse events (AEs) were graded by NCI CTCAE v4.03. Several biomarkers were explored, including PD-L1 by SP263 assay, tissue tumor mutation burden (tTMB) by whole exome sequencing (WES) from FFPE tissue, blood TMB (bTMB) by multi-gene panel based next-generation sequencing (NGS) from blood ctDNA. Results: As of 19 JUL 2019, 213 pts, median age of 55 (range: 21-75) years, were enrolled and 109 of 213 pts were still in treatment. The median dosing number was 7.5 (range: 1~41). Treatment-related AEs (TRAEs) occurred in 185 patients (70%), of which mostly were CTCAE grade 1-2. The most frequent TRAEs were related to hepatotoxicity, included “ALT increased” (32/213), “AST increased” (32/213), “blood bilirubin increased” (25/213). 53 of 163 pts, who received ≥1 response evaluation, achieved response (PR+CR, unconfirmed response included), including GC (4/21), EC (5/25), BTC (3/10), NSCLC (8/32), nasopharynx cancer (10/26),UC (2/8), HCC (0/12), cHL (18/21) and peripheral T/NK cell lymphoma (3/8). In all solid tumor types, pts with PD-L1-positive tumors experienced clinical benefit with significantly higher ORR (39.6% vs 14.5%, p=0.0025) and longer PFS (p=0.0241). ORR was higher for PD-L1 positive (TC≥25%) pts with lung cancer (66.7% vs 20.0%, p=0.051). For pan-caner analysis, ORR benefits of GLS-010 were also enhanced (51.9% versus 26.4%, p=0.0298) in pts with tTMB-high (>75th percentile, of each tumor type) versus tTMB-low. Pairing tTMB and survival data were analyzed in 129 pts, and tTMB-high pts benefit more with a significantly improved PFS (p=0.011). Also, improved PFS was observed in tTMB-high pts with EC (p=0.0059). For bTMB-high group, pts with EC achieved higher ORR (42.9% vs 6.3%, p=0.0672), which translated into PFS benefits (p=0.03). Conclusion: In conclusion, it is suggested that GLS-010 was well tolerated and had durable antitumor activity in Chinese tumor pts. PD-L1 has showed to be predictive of GLS-010 activity in solid tumors, especially in lung cancer. For pan-cancer analysis, it is preliminarily demonstrated that tTMB may be valuable biomarkers to predict the treatment response and benefit of GLS-010. For Chinese EC pts, tTMB and bTMB may be of value in predicting the response to PD-1 inhibitor. Citation Format: Lin Shen, Jifang Gong, Yuqin Song, Dingwei Ye, Zhihao Lu, Siyang Wang, Peijian Peng, Jianhua Chen, Ou Jiang, Guojun Zhang, Yuxian Bai, Jianji Pan, Chunguang Ma, Li Chen, Yi Ba, Qi Li, Ping Lu, Lingli Zhang, Xianli Yin, Shanzhi Gu, Huilai Zhang, Hang Su, Yongsheng Jiang, Bangwei Cao, Weiqing Han, Yan Sun, Feng Zhang, Weiwei Ouyang, Haiying Dong, Jianming Guo, Yabing Guo, Chongyuan Xu, Junyuan Qi, Li Wang, Jun Lv, Xiang Wang, Chris Chen, Jing Li, Yong Zheng, Ge Jin, Yining Yang, Guodong Zhao, Fan Yang, Kehui Xu, Xiangying Liang, Zhaoyang Pan, Haijin Meng. GLS-010, a novel fully human anti-PD-1 mAb in patients with advanced tumor: Preliminary results of a Phase Ib clinical trial [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3275.

Borehole radar (BHR) is a highly efficient geophysical exploration tool, however, the application is limited due to relatively small signal to noise ratio (SNR) of the testing data. Empirical Mode Decomposition (EMD) is a data processing method, which takes the particular advantage in analyzing the nonlinear and non-stationary data. This paper introduces the fundamentals of EMD method and the complex signal analysis theory, and focuses on the sufficient conditions and specific decomposition steps for signal processing based on the EMD. Then an actually radar profile, which was obtained by a BHR system in a limestone fracture zone, is used as an example to be analyzed in the following processes. Firstly, the original radar profile is preprocessed to avoid the mode confusion and noise interference to the radar echo. Secondly, the EMD method is used to process a single-channel radar data, and analyze the high-low frequency components of the radar signal. Thirdly, the various intrinsic mode of the preprocessing radar profile is also obtained by the EMD. Finally, we reconstruct the intrinsic mode profile, which contains the effective formation information, calculate the complex signals of the reconstruction radar profile using the Hilbert transform (HT), extract the three characteristic parameters such as instantaneous amplitude, instantaneous phase and instantaneous frequency, and draw the separate instantaneous parameters profiles. The results demonstrate that the EMD method has the strong adaptability in processing the BHR signal under a low SNR and the capability to separate the high-low components of the radar echo effectively. The three-instantaneous information produced by the EMD method and complex signal analysis technique, can highlight the abnormal geological feature, provide the theoretical basis and mutual authentication information for evaluating the original radar profile, and avoid the deviation relying solely on a time-distance profile.

Location k-anonymity techniques typically use anonymous spatial region to ensure privacy. But these solutions are vulnerable to multiple queries attacks and inference attacks. Failing to account for the obstacle in geographic space is a severe problem since adversaries will surely regard these constraints. A novel framework is proposed to enhance location-dependent queries, based on the theoretical work of k-anonymity and Voronoi diagrams, allows a user to express service requirement and privacy requirement by specifying a region and an appropriate value of k. A trusted anonymity server form a restricted set (k, r, s), which is composed of a number of discrete points to meet the requirements for location k-anonymity and location l-diversity. The location-based services (LBS) server implements an efficient algorithm for continuous- region-query processing. Simulation results demonstrated that the framework is superior to previous works in terms of privacy. Moreover, discreteness and randomness of the anonymous set are conducive to resisting location tracking attacks.

In opportunistic networks (OppNets), instead of assuming a complete path, messages are exchanged opportunistically when two nodes encounter. To support efficient and reliable end-to-end messaging in OppNets, a number of routing protocols based on network coding have been proposed. However, few efforts in the studies focus on opportunistic network coding (ONC). It is because the coding opportunities do not probably exist in OppNets due to nodal mobility, low density, lossy link, etc. In this paper, an ONC routing model for OppNets based on a new hybrid communication scheme was proposed. The communication scheme combines contact-based communication mode used by most routing protocols in OppNets and contact duration-based communication mode employed by few routing protocols in OppNets. We also designed an ONC routing protocol based on the ONC routing model in OppNets. Simulated results show that compared with Epidemic routing, the ONC routing can achieve higher delivery ratio and lower delay but consume fewer network cost.

Three-dimensional (3-D) numerical simulations combined with field experiments to study the radar wave responses in a sandstone formation are described. A borehole radar system was used to perform GPR surveys in a conductive sandstone. Finite-difference time-domain (FDTD) modeling is an economical and efficient method to analyze and interpret the experimental results. Using a priori information of the test site and the instrument parameters, a 3-D FDTD code based on perfectly matched layer (PML) boundary conditions was adopted to establish simulation models to study the conductivity impact on the radar response. In the single-hole reflection models, under the condition of σ/(ωε) << 1, a borehole radar can detect targets several meters away from the borehole. In this case, the amplitude attenuation of the radar wave changes linearly as the conductivity increases. However, the detecting capability declines rapidly for the two-way attenuation. The cross-hole tomography simulations are in accordance with the result of the tomography survey, which indicates that the conductivity of the site is about 0.015 S/m to 0.02 S/m, and the attenuation coefficient is between 8.9 dB/m and 11.8 dB/m. The reflected wave of the targets, a cliff and another borehole, cannot clearly be identified in the single-hole reflection image. This is supported by the tomographic image, which illustrates that the radar wave attenuation is significant in the sandstone formation. Therefore, the borehole radar system cannot detect the targets in this highly conductive sandstone.

Quantum sealed-bid auction (QSA) has been widely studied in quantum cryptography. For a successful auction, post-confirmation is regarded as an important mechanism to make every bidder verify the identity of the winner after the auctioneer has announced the result. However, since the auctioneer may be dishonest and collude with malicious bidders in practice, some potential loopholes could exist. In this paper, we point out two types of collusion attacks for a particular post-confirmation technique with EPR pairs. And it is not difficult to see that there exists no unconditionally secure post-confirmation mechanism in the existing QSA model, if the dishonest participants have the ability to control multiparticle entanglement. In the view of this, we note that some secure implementation could exist if the participants are supposed to be semi-quantum, i.e., they can only control single photons. Finally, two potential methods to design post-confirmation mechanism are presented in this restricted scenario.

The centralized and distributed models are the main system architecture of privacy protection in location-based services (LBS). In the model of centralized, the trusted third party (TTP) is used to provide location privacy, but it is usually thought as the point of attack and the bottleneck of service, which makes the distributed model attract more attention. However, although a large number of algorithms were proposed under this model, they were mainly focussed on the protection of the snapshot query and difficult to provide privacy in the continuous query. Especially that, with the difference of anonymous users, the adversary can get rid of the anonymous users and identify the issuer, and then the privacy of the issuer will be revealed. In order to deal with this problem, we propose an uncertain continuous collaborative users finding algorithm (UCCUFA), which utilizes the uncertainty cells of region grid and the collaborative users to provide query results to make the issuer hiding behind the collaborative users. In this algorithm, all query results are provided by collaborative users, and no information interacted between the issuer and the LBS server during the procedure of continuous query. At last, we utilize the security analysis and experimental results further verify the effectiveness of location privacy protection and the performance efficiency of our proposed algorithm.

Sensitive forensics for those who are involved in confidential events has received increasingly close attention, yet most of the work is intended to deal with the forensics on the personal computers. In contrast, this article presents our study of the sensitive forensics on mobiles. For the existing methods, it's time-consuming and unpractical because they depend on the manual operation. This task is further complicated by the fact that the words used in mobile messages are usually informal. To address this problem, we present a novel SVDD named N-SVDD that takes advantage of two algorithms to account for the informal words. The first is the k-means algorithm to reduce the operation time. The second is local density algorithm which can improve the accuracy effectively. Our experiments on a real-world dataset that includes mobile id, call log, short messages and social text show that our proposed methods improve the retrieval performance of existing model and that these improvements are statistically significant.

Proxy re-encryption (PRE) is an important cryptographic primitive used for private information sharing. However, the recent advance in quantum computer has potentially crippled its security, as the traditional decisional Diffie-Hellman (DDH)-based PRE is venerable to the quantum attack. Thus, learning with errors (LWE)-based PRE schemes, as a kind of latticebased construction with the inherent quantum-resistant property, has attracted special research interest. Unfortunately, the main drawback of lattice-based public key encryption scheme is noise management after multiplication evaluation. Many cryptographers have been devoted to controlling the expansion of noise. In this line of work, Dagdelen-Gajek-G¨opfert (DGG) put forth the notion of learning with errors in the exponent (LWEE) which is based on lattice and group-theoretic assumption, meanwhile demonstrated a paradigm for constructing efficient quantum resistance public key schemes. In this paper, on top of DGG, we construct a single-bit, single-hop and unidirectional LWEE- based PRE scheme with indistinguishable chosen plaintext attack (IND-CPA) security. To the best of our knowledge, our scheme is the first LWEE-based PRE scheme.

An impulse borehole radar (BHR) prototype system was developed for the exploration of complicated oil and gas reservoirs. In an abandoned limestone mine, the cliff wall and a metal-plate were selected as the imaging targets to evaluate the detection performance of the prototype system. The unknown fractures surrounding the borehole produced complex reflections that were not beneficial to effectively extract the targets echo and verify the detection range of the radar prototype. The finite-difference time-domain (FDTD) radar wave propagation models were developed for simulating the verified experiments. The fractures in the FDTD models were produced by synthetic discrete-fracture network (DFN). The simulation results objectively explained the detection range of the impulse BHR prototype can reach up to 10 m in the limestone formation, despite being filled with unknown fractures. Therefore, the numerical simulation can serve as an effective method to explain the experimental results of the impulse BHR well logging survey.

An Ultrawideband Antipodal Vivaldi Antenna with compact structure for borehole radar application is reported in this paper. The antenna is embedded in a cylindrical fiber-reinforced plastic (FRP) structure, operating in the frequency range from 600 MHz to more than 4 GHz. A metal reflector is attached to the cylindrical FRP to improve the direction of the antenna especially in low frequency. The simulation results show that good radiation patterns with direction of 4.6–8.7 dBi in end-fire direction is achieved in the whole working band, which indicates that the proposed antenna is suitable for directional borehole radar system.

The ciphertext-policy attribute-based proxy re-encryption (CP-ABPRE) scheme supports access control and can transform a ciphertext under an access policy to a ciphertext under another access policy without decrypting the ciphertexts, which is flexible and efficient for cloud sharing. The existing CP-ABPRE schemes are constructed by bilinear pairing or multi-linear maps which are fragile when the post-quantum future comes. This paper presents an efficient unidirectional single-hop CP-ABPRE scheme with small public parameters from a lattice. For the transformation between two access structures, they are required to be disjoint. This paper uses the trapdoor sampling technique to generate the decryption key and the re-encryption key in constructing the scheme, and uses the decompose vectors technique to produce the re-encrypted ciphertexts in order to control their noise. Finally, we extended the scheme to a unidirectional single-hop CP-ABPRE scheme with keyword search for searching the encrypted data. Both schemes were proved secure under the learning with errors assumption, which is widely believed to be secure in quantum computer attacks. To the best of our knowledge, our scheme is the first CP-ABPRE scheme based on the learning with errors assumption.

Understanding security failures of cryptographic protocols is the key to both patching existing protocols and designing future schemes. The design of secure remote user authentication schemes based on elliptic curve crypto-graphy (ECC) for mobile applications is still quite a challenging problem, though many schemes have been published lately. In this paper, we analyze an efficient ID-based scheme for mobile client-server environment without the MapToPoint function introduced by He et al. in 2012. This proposal attempts to overcome many of the well known security and efficiency shortcomings of previous schemes, and it also carries a claimed proof of security in the random oracle model. However, notwithstanding its formal security arguments, we show that He et al.'s protocol even cannot attain the basic goal of mutual authentication by demonstrating its vulnerabilities to reflection attack and parallel session attack. Besides these two security vulnerabilities, their scheme also suffers from some practical pitfalls such as user anonymity violation and clock synchronization problem. In addition, we carry out an investigation into their security proof and propose some changes to the scheme so that it can achieve at least its basic security goal, in the hope that similar mistakes are no longer made in the future.