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Among the advanced methods, differential privacy (DP), introducing independent Laplace noise, has become an influential privacy mechanism owing to its provable and rigorous privacy guarantee. Nonetheless, in practice, POI data to be protected is always correlated, while independent noise may cause undesirable information disclosure than expected. Recent researches attempt to optimize the sensitivity function of DP with consideration of the correlation strength between POI—but there is a drawback in a substantial growth of noise level. To remedy this problem, this paper exploits the degradation of DP in expected privacy levels for correlated POI data and proposes a solution to mitigate it. We propose a generalized Laplace mechanism to achieve privacy guarantees. Specifically, we design a practical iteration mechanism, including an update function, to conduct a generalized Laplace mechanism when facing large scale queries. Experimental evaluation on real-world datasets over multiple fields show that our solution consistently outperforms state-of-the-art mechanisms in data utility while providing the same privacy guarantee as other approaches for correlated POI data. [ABSTRACT FROM AUTHOR]

Privacy preserving methods supporting for data aggregating have attracted the attention of researchers in multidisciplinary fields. Among the advanced methods, differential privacy (DP) has become an influential privacy mechanism owing to its rigorous privacy guarantee and high data utility. But DP has no limitation on the bound of noise, leading to a low-level utility. Recently, researchers investigate how to preserving rigorous privacy guarantee while limiting the relative error to a fixed bound. However, these schemes destroy the statistical properties, including the mean, variance and MSE, which are the foundational elements for data aggregating and analyzing. In this paper, we explore the optimal privacy preserving solution, including novel definitions and implementing mechanisms, to maintain the statistical properties while satisfying DP with a fixed relative error bound. Experimental evaluation demonstrates that our mechanism outperforms current schemes in terms of security and utility for large quantities of queries. [ABSTRACT FROM AUTHOR]

We sought to investigate the outcomes of posterior-only approach using polyetheretherketone (PEEK) cage combined with single-segment instrumentation (modified-approach) for mono-segment lumbar tuberculosis in children. Between February 2008 and August 2017 in our hospital, 18 children with single-segment lumbar tuberculosis enrolled in this study were treated by modified-approach. Medical records and radiographs were retrospectively analyzed. Mean follow-up time was 54.6 ± 12.1 months. No severe complications were noted to have occurred. Measures indicated there was satisfactory bone fusion for all patients. Mean Cobb angles were significantly decreased from preoperative angle (19.8° ± 13.1°) to those both postoperatively (− 4.9° ± 7.6°) and at final follow-up (− 3.5° ± 7.3°) (both P < 0.05), with a mean angle loss of 1.7° ± 0.9°. The erythrocyte sedimentation rate (ESR) returned to normal levels for all patients within 3 months postoperatively. All patients had significant postoperative improvement in neurological performance. The modified-approach was an effective and feasible treatment option for mono-segment children with lumbar tuberculosis. Such procedures can likely help patients by increasing retainment of lumbar mobility and reducing invasiveness. [ABSTRACT FROM AUTHOR]

Although data analysis and mining technologies can efficiently provide intelligent and personalized services to us, data owners may not always be willing to share their true data because of privacy concerns. Recently, differential privacy (DP) technology has achieved a good trade-off between data utility and privacy guarantee by publishing noisy outputs. Nonetheless, DP still has a risk of privacy leakage when handling correlated data directly. Current schemes attempt to extend DP to publish correlated data, but are faced with the challenge of violating DP or low-level data utility. In this paper, we try to explore the essential cause of this inapplicability. Specifically, we suppose that this inapplicability is caused by the different correlations between noise and original data. To verify our supposition, we propose the notion of Correlation-Distinguishability Attack (CDA) to separate IID (Independent and Identically Distributed) noise from correlated data. Furthermore, taking time series as an example, we design an optimum filter to realize CDA in practical applications. Experimental results support our supposition and show that, the privacy degree of current approaches has a degradation under CDA. [ABSTRACT FROM AUTHOR]

The rapid development of data sharing applications brings a serious problem of privacy disclosure. As an effective privacy-preserving method, the differential privacy, which strictly defines the privacy-preserving degree and data utility mathematically, can balance the privacy and data utility. However, the differential privacy has a hypothesis premise that the raw data are accurate without any error, so it could not limit the privacy security and the data utility to the expected range when processing data with errors. Hence, this paper focuses on the study on the influence of data errors on differential privacy. Taking the random error as an example, we analyze the influence mode and mechanism of data errors on differential privacy, especially on the privacy budget ε . The theoretical derivations and experimental simulations prove that the Laplace mechanism still preserves ε ′ -indistinguishability for data with errors. Moreover, the random algorithm can realize the expected privacy preserving strength by adding less noise compared with the algorithm that do not consider data errors, and has a better data utility by reducing the unnecessary cost of utility. This paper defines the research directions on the differential privacy theory concerning of data errors, and provides the foundations of perfecting the theory system and promoting the practicality of the differential privacy. [ABSTRACT FROM AUTHOR]

Design: This a retrospective study in single centre.Objective: The objective of this retrospective clinical study is to compare the long-term clinical efficacy of posterior long-segment and short-segment fixation with single-stage transpedicular debridement and fusion for the treatment of thoracolumbar spinal tuberculosis in adults.Methods: Sixty-six cases of thoracolumbar tuberculosis were treated by single-stage transpedicular debridement, bone graft fusion, and pedicle screw fixation. Thirty-five cases were under long-segment fixation (group A) and 31 cases were under short-segment fixation (group B). These patients were followed up for a minimum of five years. The clinical and radiographic results for these patients were analyzed and compared.Results: All 66 patients were completely cured during the follow-up. All patients had significant improvement of neurological condition and visual analogue scale pain scores at the final follow-up. The average operation duration and blood loss in group A were more than that in group B. Kyphosis Cobb angle of both groups was significantly corrected after surgical management. The correction rate of Cobb angle in group A was significantly higher than that in group B at the time of immediate post-operative period or the last follow-up (P < 0.05). The correction loss of group A was significantly less than that in group B (P < 0.05).Conclusion: Both posterior long-segment and short-segment pedicle screw fixations for the treatment of thoracolumbar spinal tuberculosis have significant effects in the correction of kyphosis and the improvement of neurological function. Although the blood loss and operation time of long-segment fixation were more than that of short-segment fixation, long-segment fixation was superior to the short-segment fixation in the correction of kyphosis and the maintenance of spinal stability, especially in the prevention of long-term correction loss. [ABSTRACT FROM AUTHOR]

In this paper, a novel reversible data hiding (RDH) scheme for encrypted digital images using integer wavelet transform, histogram shifting and orthogonal decomposition is presented. This scheme takes advantage of the Laplacian-like distribution of integer wavelet high-frequency coefficients in high frequency sub-bands and the independence of orthogonal coefficients to facilitate data hiding operation in encrypted domain, and to keep the reversibility. Experimental results has demonstrated that this scheme outperforms all of other existing RDH schemes in encrypted domain in terms of higher PSNR at the same amount of payload. Compared with the state-of-the-arts, the proposed scheme can be applied to all natural images with higher embedding rate. [ABSTRACT FROM AUTHOR]

Caching can prepare data for computational tasks in advance by tracking the requirements and behaviors of distributed geographical information systems to reduce network latency and improve computational performance. This paper presents an enhanced method to actively cache data for data-intensive computations that considers both data relationships and the timeliness of those relationships. First, the access correlations, the correlation steps and the times of the correlations are computed based on the behaviors of the computational tasks. Because the influence of historically accessed records will decrease gradually over time, only recently accessed records are used. To track changes in the relationships and prevent cache waste problems, each record is given a different age-based weight. A conditional caching probability can then be computed based on the timeliness relationships, which can be used to find the appropriate data to compute simultaneously. Finally, we present several experiments that compare the proposed method with techniques that use other data placement strategies, active caching strategies and passive caching algorithms. The results show that the proposed model has better performance than other algorithms in all respects. In addition, the proposed model results in a lower cache replacement ratio. The experiments with different data sets on different data scales indicate that the proposed algorithm can also be used in large-scale distributed environments. [ABSTRACT FROM AUTHOR]

Cloud computing systems provide high-performance computing resources and distributed storage space to deal with data-intensive computations. Data scheduling between data centers is becoming indispensable for the cloud computing systems in which a mass of large datasets is stored at different data centers and inter-center data accesses are needed in data analytics. However, the performance of data scheduling is highly dependent upon the rationality of data placement. Data placement is a key optimization method for reducing data scheduling between data centers and realizing statistical I/O load balancing, accordingly reducing the mean computation execution time. This paper proposes a data placement strategy, DCCP, which is developed based on dynamic computation correlation. DCCP places the datasets with high dynamic computation correlations at the same data center considering the I/O load and the capacity load of data centers; when computations are scheduled for this data center, most of the datasets they process are stored locally, and thus the mean computation execution time can be reduced. Evidence from a large number of experiments proves that the DCCP can achieve the statistical I/O load balancing and the capacity load balancing of data centers, thus reducing the total data scheduling between data centers as much as possible at a very low time complexity, even as the numbers of datasets and data centers increase. [ABSTRACT FROM AUTHOR]

This paper proposes a novel multiple watermarking scheme based on orthogonal decomposition (MWOD). In the first phase, based on orthogonal decomposition, the host data selected from multimedia data are divided into mutually independent multiple domains. Then multiple watermarks without need for considering the special correlation among them can respectively be embedded into these different domains even using different embedding algorithms. There is no mutual interference among watermarked domains so that multiple watermarks can be flexibly embedded in the distribution of the multimedia cover. Through theoretical analysis, the security of multiple watermarking operands is validated, which means that MWOD can ensure the security of watermarking operation domains. Therefore, media providers and service providers can embed their unique information step-by-step into digital multimedia using their own operation domain keys in MWOD, which can be used to identify media content's ownership or trace the illegal redistributors. Experimental results and analysis demonstrate the feasibility and robustness of MWOD. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the clinical efficacy and feasibility of surgical treatment for lumbosacral junction tuberculosis by one-stage posterior debridement, interbody fusion, lumbopelvic fixation, and postural drainage. Methods: A total of 15 cases with lumbosacral junction tuberculosis treated by one-stage posterior debridement, interbody fusion, lumbopelvic fixation, and postural drainage in our center from January 2005 to October 2011 were studied. Lumbosacral angle, visual analog scale (VAS), and neurological performance were assessed before and after surgery. Results: All patients were followed for 28-56 months post-operation (average, 40.7 ± 7.7 months). No severe complications occurred. Bone fusion occurred in all patients at a mean of 8.4 months (range 6-12 months) after surgery. The mean lumbosacral angle was significantly increased from the mean preoperative angle (20.9° ± 1.8°) both post-operatively (26.5° ± 1.6°) and at final follow-up (25.3° ± 1.4°) (both P < 0.05). All patients had significant post-operative improvement in neurological performance and VAS scores. Conclusions: Our results suggest that one-stage posterior debridement, interbody fusion, lumbopelvic fixation, and postural drainage can be an effective and feasible treatment option for lumbosacral junction tuberculosis, offering fewer complications and a better quality of life. [ABSTRACT FROM AUTHOR]

Commutative Encryption and Watermarking (CEW) is a technology combined with encryption and watermarking, which is used for providing comprehensive security protection for multimedia information. This paper presents a novel CEW scheme based on orthogonal decomposition. Different from current CEW, the proposed CEW not only achieves the integration of encryption and watermarking in the final data but also has no specific restrictions in selecting encryption and watermarking algorithms. Therefore, the proposed CEW possesses higher security and applicability. Experimental results demonstrate that the proposed CEW can keep the performances of selected encryption and watermarking algorithm and show more robustness than other current CEW schemes. [ABSTRACT FROM AUTHOR]

Purpose: The correction of severe post-tubercular kyphosis (PTK) is complex and has the disadvantage of being multistaged with a high morbidity. In this study, we evaluated the outcomes of children who underwent single-stage closing-opening wedge osteotomy as a surgical treatment of PTK of the thoracolumbar spine. Method: Our study group included 12 children with thoracolumbar PTK (seven boys and five girls) with an average age of 9.4 years (range 6-12 years), who were treated at our institution from January 2004 to October 2009. The American Spinal Injury Association Impairment Scale and visual analog scale score were used to classify neurologic function. All patients underwent halo-pelvic traction before surgery and were treated with single-stage closing-opening wedge osteotomy. Result: The duration of surgery averaged 99 min (range 70-150 min). Average blood loss was 782 ml (range 560-1,200 ml), and the average length of hospital stay was 12 days (range 8-16 days). The neurological function of all patients improved significantly after the procedure. The mean preoperative kyphotic angle was 83.3° (range 59-118°), which had reduced to 27.6° (range 20-38°) at the final follow-up visit. All patients had solid fusion, and no major complications were observed through the final follow-up visit. Conclusion: Single-stage closing-opening wedge osteotomy is an effective method to correct severe thoracolumbar PTK. A main advantage of the procedure is that it is a posterior-only, single-staged surgery, allowing for significant correction with minimal complications. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the clinical efficacy and feasibility of one-stage surgical treatment for thoracic spinal tuberculosis with adjacent segments lesion by internal fixation, transpedicular debridement, and combined interbody and posterior fusion via a posterior-only approach. Materials and methods: Twenty-one patients (thirteen males, eight females) with thoracic tuberculosis whose lesions were confined to two adjacent segments were studied retrospectively. All patients were treated with one-stage surgical treatment by internal fixation, transpedicular debridement, and combined interbody and posterior fusion via a posterior-only approach. The American Spinal Injury Association (ASIA) impairment scale was used to assess neurological function. Thoracic Cobb angle was used to assess thoracic kyphosis. Operating time, blood loss, complications, neurological function, deformity correction and interbody fusion were investigated. Results: Average mean operating time was 231.4 ± 31.9 min, and evaluated blood loss during operation was 880.2 ± 112.7 ml. All patients were followed up for 22-41 months postoperatively (average 29.8 ± 5.4 months). All patients had significant postoperative improvement in ASIA classification scores. The thoracic kyphotic angles were significantly decreased to 9°-25° postoperatively (average 16.7° ± 4.4°), and at final follow-up were 10°-27°(average 17.7° ± 4.4°). No severe complications or spinal cord injury occurred. The erythrocyte sedimentation rate recovered to normal within 3 months postoperatively in all patients. All patients got bony fusion within 6-9 months after surgery. Conclusions: One-stage transpedicular debridement, posterior instrumentation and combined interbody and posterior fusion via a posterior-only approach can be an effective and feasible treatment method for thoracic spinal tuberculosis. [ABSTRACT FROM AUTHOR]

Purpose: Retrospective analysis of the clinical efficacy and feasibility of patients with thoracolumbar spinal tuberculosis with psoas abscesses treated by one-stage posterior transforaminal lumbar debridement, interbody fusion, posterior instrumentation, and postural drainage. Method: A total of 18 patients with thoracolumbar tuberculosis (TB), between February 2007 and February 2011, underwent one-stage posterior transforaminal lumbar debridement, interbody fusion, posterior instrumentation, and postural drainage. And the clinical efficacy was evaluated based on surgery duration time, the blood loss, the postural drainage of time, neurological status that was recorded by American Spinal Injury Association (ASIA) Impairment Scale, the fate of bone graft fusion, kyphosis angle, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), which were collected at certain time. Results: The average follow-up period was 34 months (range 18-48 months). 18 patients suffered from seriously neurological deficits pre-operatively, of which 16 patients returned to normal at final follow-up. The surgery duration time was 197 ± 37.9 min, and the blood loss was 815 ± 348.5 ml. The postural drainage of time was 7.2 ± 2.7 days. The psoas abscesses disappeared in all cases, within the time range of 6-9 months (mean 7.4 ± 1.2 months). All patients of the grafted bones were thoroughly fused, with a fusion time ranging from 4 to 12 months (mean 7.8 months). Kyphosis angle was 44.32 ± 7.26° on average pre-operative and returned to 11.72 ± 2.85° at 6 weeks after operation; kyphosis angle was 13.10 ± 2.39° at final follow-up. The values of ESR and CRP were significant declined at 6 weeks post-operative, and returned to normal levels at final follow-up. Conclusion: With standardized anti-TB chemotherapy, thoracolumbar spinal tuberculosis with psoas abscesses could be effectively treated by one-stage posterior transforaminal lumbar debridement, interbody fusion, posterior instrumentation, and postural drainage. [ABSTRACT FROM AUTHOR]

Extraction of individual Motor Unit Action Potentials (MUAPs) from a surface ElectroMyoGram (EMG) is an essential but challenging task for clinical study and physiological investigation. This paper presents an automatic decomposition of surface EMGs using a self-organised ART2 neural network. In our approach, MUAP peaks are first detected using a Weighted Low-Pass Differential (WLPD) filter. A modified ART2 network is then utilised to classify MUAPs based on MUAP waveforms and firing time information. Individual MUAP trains are identified from real surface EMG signals recorded during weak contraction, and also from simulated surface EMGs. The firing statistics and the waveforms of individual MUAPs are then extracted. A number of computer tests on 50 simulated and real surface EMGs of limb muscles show that up to five MUAP trains can be effectively extracted, with their waveforms and firing parameters estimated. Being able to decompose real surface EMGs has essentially demonstrated the potential applications of our approach to the noninvasive diagnosis of neuromuscular disorders. [ABSTRACT FROM AUTHOR]