bluuebunny/crossref_metadata_2025 huggingface dataset:
Lower bounds for external memory integer sorting via network coding
Authors: Farhadi Alireza , Hajiaghayi Mohammad Taghi , Larsen Kasper Green , Shi Elaine
Published: September 2020

Sorting extremely large datasets is a frequently occurring task in practice. These datasets are usually much larger than the computer's main memory; thus, external memory sorting algorithms, first introduced by Aggarwal and Vitter, are often used. The complexity of comparison-based external memory sorting has been understood for decades by now; however, the situation remains elusive if we assume the keys to be sorted are integers. In internal memory, one can sort a set of
n
integer keys of Θ(lg
n
) bits each in
O
(
n
) time using the classic Radix Sort algorithm; however, in external memory, there are no faster integer sorting algorithms known than the simple comparison-based ones. Whether such algorithms exist has remained a central open problem in external memory algorithms for more than three decades.

In this paper, we present a
tight
conditional lower bound on the complexity of external memory sorting of integers. Our lower bound is based on a famous conjecture in network coding by Li and Li, who conjectured that network coding cannot help anything beyond the standard multicommodity flow rate in undirected graphs.

The only previous work connecting the Li and Li conjecture to lower bounds for algorithms is due to Adler et al. Adler et al. indeed obtain relatively simple lower bounds for
oblivious
algorithms (the memory access pattern is fixed and independent of the input data). Unfortunately, obliviousness is a strong limitation, especially for integer sorting: we show that the Li and Li conjecture implies an Ω(
n
lg
n
) lower bound for internal memory
oblivious
sorting when the keys are Θ(lg
n
) bits. This is in sharp contrast to the classic (nonoblivious) Radix Sort algorithm. Indeed, going beyond obliviousness is highly nontrivial; we need to introduce several new methods and involved techniques, which are of their own interest, to obtain our tight lower bound for external memory integer sorting.
Sanity vs. invisible markings
Authors: Neville-Neil George V.
Published: September 2020

Tabs vs. spaces
Security Analysis of SMS as a Second Factor of Authentication
Authors: Jover Roger Piqueras
Published: September 2020

Despite their popularity and ease of use, SMS-based authentication tokens are arguably one of the least secure forms of two-factor authentication. This does not imply, however, that it is an invalid method for securing an online account. The current security landscape is very different from that of two decades ago. Regardless of the critical nature of an online account or the individual who owns it, using a second form of authentication should always be the default option, regardless of the method chosen. In the wake of a large number of leaks and other intrusions, there are many username and password combinations out there in the wrong hands that make password spraying attacks cheap and easy to accomplish.
Intergenerational Economic Mobility for Low-Income Parents and Their Children: A Dual Developmental Science Framework
Authors: Sabol Terri J. , Sommer Teresa Eckrich , Chase-Lansdale P. Lindsay , Brooks-Gunn Jeanne
Published: September 2020

In this review we bring a psychological perspective to the issue of intergenerational economic mobility. More specifically, we present a new dual developmental science framework to consider the educational outcomes of parents and children together in order to foster economic mobility. We focus on two key populations: children in early childhood (from birth to age 6) and parents in early adulthood (in their 20s and early 30s). We posit that mastery of three sets of developmental tasks for each generation—academic/language skills, self-regulation/mental health, and parent-child relationship—will lead to improved educational outcomes for both. Taken as a whole, the dual developmental science framework integrates theory and research on single-generation development (i.e., children or parents) with dynamic and bidirectional theories about the interdependence of children and parents over time.We conclude the review by evaluating existing education interventions and research using the dual developmental science framework, and we discuss opportunities for innovation.
Impaired glucose partitioning in primary myotubes from severely obese women with type 2 diabetes
Authors: Zou Kai , Turner Kristen , Zheng Donghai , Hinkley J. Matthew , Kugler Benjamin A. , Hornby Pamela J. , Lenhard James , Jones Terry E. , Pories Walter J. , Dohm G. Lynis , Houmard Joseph A.
Published: September 2020

The purpose of this study was to determine whether intramyocellular glucose partitioning was altered in primary human myotubes derived from severely obese women with type 2 diabetes. Human skeletal muscle cells were obtained from lean nondiabetic and severely obese Caucasian females with type 2 diabetes [body mass index (BMI): 23.6 ± 2.6 vs. 48.8 ± 1.9 kg/m2, fasting glucose: 86.9 ± 1.6 vs. 135.6 ± 12.0 mg/dL, n = 9/group]. 1-[14C]-Glucose metabolism (glycogen synthesis, glucose oxidation, and nonoxidized glycolysis) and 1- and 2-[14C]-pyruvate oxidation were examined in fully differentiated myotubes under basal and insulin-stimulated conditions. Tricarboxylic acid cycle intermediates were determined via targeted metabolomics. Myotubes derived from severely obese individuals with type 2 diabetes exhibited impaired insulin-mediated glucose partitioning with reduced rates of glycogen synthesis and glucose oxidation and increased rates of nonoxidized glycolytic products, when compared with myotubes derived from the nondiabetic individuals ( P < 0.05). Both 1- and 2-[14C]-pyruvate oxidation rates were significantly blunted in myotubes from severely obese women with type 2 diabetes compared with myotubes from the nondiabetic controls. Lastly, concentrations of tricarboxylic acid cycle intermediates, namely, citrate ( P < 0.05), cis-aconitic acid ( P = 0.07), and α-ketoglutarate ( P < 0.05), were lower in myotubes from severely obese women with type 2 diabetes. These data suggest that intramyocellular insulin-mediated glucose partitioning is intrinsically altered in the skeletal muscle of severely obese women with type 2 diabetes in a manner that favors the production of glycolytic end products. Defects in pyruvate dehydrogenase and tricarboxylic acid cycle may be responsible for this metabolic derangement associated with type 2 diabetes.
Vestibular modulation of skin sympathetic nerve activity in sopite syndrome induced by low-frequency sinusoidal motion
Authors: Foster Monique , Singh Natasha , Kwok Kenny , Macefield Vaughan G.
Published: September 2020

Little is known about the autonomic consequences of sopite syndrome—the drowsiness that can be induced by low-amplitude cyclic motion. We recorded skin sympathetic nerve activity (SSNA) in seated participants exposed to slow sinusoidal linear acceleration (0.03–0.2 Hz), which preferentially activates hair cells in the utricular part of the otolithic organs, at amplitudes that generated no sensations of motion. At all frequencies, there was a clear vestibular modulation of SSNA and cutaneous vasoconstriction.
Blood pressure drives multispectral tuning of inspiration via a linked-loop neural network
Authors: Segers Lauren S. , Nuding Sarah C. , Ott Mackenzie M. , O’Connor Russell , Morris Kendall F. , Lindsey Bruce G.
Published: September 2020

The brain network that supports cardiorespiratory coupling remains poorly understood. Using multielectrode arrays, we tested the hypothesis that blood pressure and baroreceptor reflexes “tune” the breathing motor pattern via a raphe-pontomedullary network. Neuron responses to changes in arterial pressure and identified functional connectivity, together with altered high frequency and slow Lundberg B-wave oscillations, support a model with linked recurrent inhibitory loops that stabilize the respiratory network and provide a path for transmission of baroreceptor signals.
Spontaneously emerging patterns in human visual cortex and their functional connectivity are linked to the patterns evoked by visual stimuli
Authors: Kim DoHyun , Livne Tomer , Metcalf Nicholas V. , Corbetta Maurizio , Shulman Gordon L.
Published: September 2020

Spontaneous brain activity was once thought to reflect only noise, but evidence of strong spatiotemporal regularities has motivated a search for functional explanations. Here we show that the spatial pattern of spontaneous activity in human high-level and early visual cortex is related to the spatial patterns evoked by stimuli. Moreover, these patterns partly govern spontaneous spatiotemporal interactions between regions, so-called functional connectivity. These results support the hypothesis that spontaneous activity serves a representational function.
Large Variations in Malaria Parasite Carriage by Afebrile School Children Living in Nearby Communities in the Central Region of Ghana
Authors: Obboh Evans K. , Okonu Ruth E. , Amoah Linda E.
Published: September 2020

Background. Indicators of successful malaria control interventions include a reduction in the prevalence and densities of malaria parasites contained in both symptomatic and asymptomatic infections as well as a reduction in malaria transmission. Individuals harboring malaria parasites in asymptomatic infections serve as reservoirs for malaria transmission. This study determined the prevalence of asymptomatic malaria parasite carriage in afebrile children attending six different schools in two districts, the Cape Coast Metropolitan Assembly (CCMA) and the Komenda Edina Eguafo Abirem (KEEA) of the Central Region of Ghana. Methods. This cross sectional study recruited afebrile children aged between 3 and 15 years old from six randomly selected schools in the Central Region of Ghana. Finger-pricked blood was collected and used to prepare thick and thin blood smears as well as spot a strip of filter paper (Whatman #3). Nested PCR was used to identify Plasmodium falciparum, Plasmodium malariae, Plasmodium ovale, and Plasmodium vivax in DNA extracted from the filter paper spots. The multiplicity of P. falciparum infection was determined using merozoite surface protein 2 genotyping. Results. Out of the 528 children sampled, PCR identified 27.1% to harbor Plasmodium parasites in asymptomatic infections, whilst microscopy identified malaria parasites in 10.6% of the children. The overall PCR estimated prevalence of P. falciparum and P. malariae was 26.6% and 1.3%, respectively, with no P. ovale or P. vivax identified by PCR or microscopy. The RDT positivity rate ranged from 55.8% in Simiw to 4.5% in Kuful. Children from the Simiw Basic School accounted for 87.5% of all the asymptomatic infections. The multiplicity of P. falciparum infection was predominantly monoclonal and biclonal. Conclusions. The low prevalence of asymptomatic malaria parasite carriage by the children living in the Cape Coast Metropolis suggests that the malaria control interventions in place in CCMA are highly effective and that additional malaria control interventions are required for the KEEA district to reduce the prevalence of asymptomatic malaria parasite carriers. No molecular evidence of P. ovale and P. vivax was identified in the afebrile children sampled from the selected schools.
Comparative Analysis of Some Structural Equation Model Estimation Methods with Application to Coronary Heart Disease Risk
Authors: Adedia David , Adebanji Atinuke O. , Appiah Simon Kojo
Published: September 2020

This study compared a ridge maximum likelihood estimator to Yuan and Chan (2008) ridge maximum likelihood, maximum likelihood, unweighted least squares, generalized least squares, and asymptotic distribution-free estimators in fitting six models that show relationships in some noncommunicable diseases. Uncontrolled hypertension has been shown to be a leading cause of coronary heart disease, kidney dysfunction, and other negative health outcomes. It poses equal danger when asymptomatic and undetected. Research has also shown that it tends to coexist with diabetes mellitus (DM), with the presence of DM doubling the risk of hypertension. The study assessed the effect of obesity, type II diabetes, and hypertension on coronary risk and also the existence of converse relationship with structural equation modelling (SEM). The results showed that the two ridge estimators did better than other estimators. Nonconvergence occurred for most of the models for asymptotic distribution-free estimator and unweighted least squares estimator whilst generalized least squares estimator had one nonconvergence of results. Other estimators provided competing outputs, but unweighted least squares estimator reported unreliable parameter estimates such as large chi-square test statistic and root mean square error of approximation for Model 3. The maximum likelihood family of estimators did better than others like asymptotic distribution-free estimator in terms of overall model fit and parameter estimation. Also, the study found that increase in obesity could result in a significant increase in both hypertension and coronary risk. Diastolic blood pressure and diabetes have significant converse effects on each other. This implies those who are hypertensive can develop diabetes and vice versa.
Patterns of Circadian Variation in 24-Hour Ambulatory Blood Pressure, Heart Rate, and Sympathetic Tone Correlate with Cardiovascular Disease Risk: A Cluster Analysis
Authors: Hyun Myung Han , Kang Jun Hyuk , Kim Sunghwan , Na Jin Oh. , Choi Cheol Ung , Kim Jin Won , Kim Eung Ju , Rha Seung-Woon , Park Chang Gyu , Lee Eunmi , Seo Hong Seog
Published: September 2020

To investigate whether specific time series patterns for blood pressure (BP), heart rate (HR), and sympathetic tone are associated with metabolic factors and the 10-year risk of atherosclerotic cardiovascular disease (ASCVD). A total of 989 patients who underwent simultaneous 24-hour ambulatory BP and Holter electrocardiogram monitoring were enrolled. The patients were categorized into sixteen groups according to their circadian patterns using the consensus clustering analysis method. Metabolic factors, including cholesterol profiles and apolipoprotein, were compared. The 10-year ASCVD risk was estimated based on the Framingham risk model. Overall, 16 significant associations were found between the clinical variables and cluster groups. Age was commonly associated with all clusters in systolic BP (SBP), diastolic BP (DBP), HR, and sympathetic tone. Metabolic indicators, including diabetes, body mass index, total cholesterol, high-density lipoprotein, and apolipoprotein, were associated with the four sympathetic tone clusters. In the crude analysis, the ASCVD risk increased incrementally from clusters 1 to 4 across SBP, DBP, HR, and sympathetic tone. After adjustment for multiple variables, however, only sympathetic tone clusters 3 and 4 showed a significantly high proportion of patients at high risk (≥7.5%) of 10-year ASCVD (odds ratio OR=5.90, 95% confidential interval CI=1.27–27.46, and P value = 0.024 and OR=15.28, 95% CI=3.59–65.11, and P value < 0.001, respectively). Time series patterns of BP, HR, and sympathetic tone can serve as an indicator of aging. Circadian variations in sympathetic tone can provide prognostic information about patient metabolic profiles and indicate future ASCVD risk.
The PARK2 Mutation Associated with Parkinson’s Disease Enhances the Vulnerability of Peripheral Blood Lymphocytes to Paraquat
Authors: Ming Fengyu , Tan Jieqiong , Qin Lixia , Zhang Hainan , Tang Jianguang , Tan Xuling , Wang Chunyu
Published: September 2020

Parkinson’s disease (PD) is the second most common neurodegenerative disease in middle‐aged and elderly people. However, the etiology and pathogenesis of PD are still unclear and there is a lack of reliable biomarkers for early molecular diagnosis. Parkin (encoded by PARK2) is a ubiquitin E3 ligase that participates in mitochondrial homeostasis, the ubiquitin‐proteasome pathway, oxidative stress response, and cell death pathways, which are involved in the pathogenesis of PD. However, Parkin is also expressed in peripheral blood lymphocytes (PBLs). In this study, permanent lymphocyte lines were established from the peripheral blood of sporadic PD (sPD) patients, PARK2 mutation carriers, and healthy controls. Reactive oxygen species (ROS), function of the mitochondrial respiratory chain complex I, and apoptosis were analyzed in the PBLs. There was no significant difference in ROS, mitochondrial respiratory chain complex I, and apoptosis between the experimental groups and the control group without paraquat treatment. Compared with the control group of healthy subjects, we found an increase of ROS (control 100 ± 0, sPD 275.53 ± 79.11, and C441R 340 ± 99.67) and apoptosis, as well as a decline in the function of mitochondrial respiratory chain complex I in PBLs of PARK2 mutation carriers and sPD after the treatment of paraquat (control 0.65 ± 0.08, sPD 0.44 ± 0.08, and C441R 0.32 ± 0.08). Moreover, overexpression of the wild‐type (WT) PARK2 in HeLa cells and immortalized PBLs could rescue mitochondrial function and partially inhibit apoptosis following paraquat treatment, while the C441R mutation could not. Thus, ROS levels, activity of mitochondrial respiratory chain complex I, and apoptosis of PBLs are potential diagnostic biomarkers of PD.
Constraint and Nonlinearization of Supersymmetric Equations with Some Special Forms of Lax Pairs
Authors: Li Hongmin
Published: September 2020

We study the null boundary problems of some classical evolution equations constrained by some special forms of Lax pairs. Furthermore, we present the constraint and nonlinearization of some supersymmetric (SUSY) equations with a special form of Lax pairs and solve the null boundary problems of these SUSY equations under the corresponding constraints.
Hybrid Adaptive Wavelet-Based Optical Flow Algorithm for Background Oriented Schlieren (BOS) Experiments
Authors: Zhang Xin-yu , Wang Li-Ming , Liu Bin , Luo Yue , Han Xing-cheng
Published: September 2020

Quantitative analysis of the flow field is an effective method to study hydrodynamics. As a flow field measurement technology, the Background Oriented Schlieren (BOS) is widely used. However, it is difficult to measure the complex transparent flow field (flow field with large refractive index gradient) using the BOS experiment. In order to overcome this difficulty and improve the accuracy of the BOS experiment, this paper presents a hybrid adaptive wavelet-based optical flow algorithm for the BOS. The current algorithm is a combination of the traditional optical flow algorithm and the wavelet-based optical flow algorithm. By adding the initial value constraints, the adaptive scale constraints, and the adaptive regularization constraints, the algorithm can effectively overcome the above-mentioned difficulty and also improve its accuracy. To further illustrate the feasibility of the proposed method, this paper uses the simulation data, the data of the DNS datasets, and the data of the BOS experiment to verify the performance of the algorithm. The experiment of comparing the proposed algorithm with the existing ones is carried out on the DNS datasets and the data of the BOS experiment. Finally, the proposed method is verified by a practical BOS experiment. The results show that the proposed algorithm can effectively improve the measurement accuracy of displacements.
Alkaloids from Cryptolepis sanguinolenta as Potential Inhibitors of SARS‐CoV‐2 Viral Proteins: An In Silico Study
Authors: Borquaye Lawrence Sheringham , Gasu Edward Ntim , Ampomah Gilbert Boadu , Kyei Lois Kwane , Amarh Margaret Amerley , Mensah Caleb Nketia , Nartey Daniel , Commodore Michael , Adomako Abigail Kusiwaa , Acheampong Philipina , Mensah Jehoshaphat Oppong , Mormor David Batsa , Aboagye Caleb Impraim
Published: September 2020

The ongoing global pandemic caused by the human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has infected millions of people and claimed hundreds of thousands of lives. The absence of approved therapeutics to combat this disease threatens the health of all persons on earth and could cause catastrophic damage to society. New drugs are therefore urgently required to bring relief to people everywhere. In addition to repurposing existing drugs, natural products provide an interesting alternative due to their widespread use in all cultures of the world. In this study, alkaloids from Cryptolepis sanguinolenta have been investigated for their ability to inhibit two of the main proteins in SARS‐CoV‐2, the main protease and the RNA‐dependent RNA polymerase, using in silico methods. Molecular docking was used to assess binding potential of the alkaloids to the viral proteins whereas molecular dynamics was used to evaluate stability of the binding event. The results of the study indicate that all 13 alkaloids bind strongly to the main protease and RNA‐dependent RNA polymerase with binding energies ranging from ‐6.7 to ‐10.6 kcal/mol. In particular, cryptomisrine, cryptospirolepine, cryptoquindoline, and biscryptolepine exhibited very strong inhibitory potential towards both proteins. Results from the molecular dynamics study revealed that a stable protein‐ligand complex is formed upon binding. Alkaloids from Cryptolepis sanguinolenta therefore represent a promising class of compounds that could serve as lead compounds in the search for a cure for the corona virus disease.
Hybrid Modification of Stone Mastic Asphalt with Cellulose and Basalt Fiber
Authors: Huang You , Liu Zhaohui , Liu Li , Zhang Yunbao , Xu Qingxiang
Published: September 2020

In this study, cellulose and basalt fiber were introduced simultaneously to stone mastic asphalt (SMA) to investigate the effects of hybrid modification on performance improvement of asphalt mixture. The study consists of three parts. The first part investigated material properties of cellulose and basalt fiber, including microscope electrical scanning. The second part conducted a series of tests to evaluate the effects of different combinations of cellulose and basalt fiber on performance. With a total addition of fiber 0.4% by the weight of mixture, five different cellulose‐basalt fiber ratios, 0 : 4, 1 : 3, 2 : 2, 3 : 1, and 4 : 0, were introduced to the asphalt mixtures. A series of tests including draindown, permanent deformation, low temperature bending, beam fatigue, and moisture damage resistance were conducted. In the final part, a benefit‐cost ratio was designed to help determine the optimum cellulose‐basalt fiber combination in the economic aspect. Results show that material properties of the two fibers are very different, including thermostability, modulus, surface, and microstructure, especially oil absorption. In general, all samples with fibers outperformed the control group in all the performance tests. Specifically, cellulose fiber improved draindown, ductility, and fatigue more significantly, whilst basalt fiber has more influence on improving permanent deformation, deflection strength, and stress sensitivity. Equal portion of cellulose and basalt fiber has the best moisture damage resistance. The mechanisms of the two fibers are different, resulting in different performance improvements on asphalt mixtures. Overall, an appropriate combination of the two fibers would produce paving materials with more balanced performance in an economical way.
The Influence of Apparent Temperature on Mortality in the Kintampo Health and Demographic Surveillance Area in the Middle Belt of Ghana: A Retrospective Time-Series Analysis
Authors: Wiru Kenneth , Oppong Felix Boakye , Agyei Oscar , Zandoh Charles , Nettey Obed Ernest , Adda Robert , Gasparrini Antonio , Asante Kwaku Poku
Published: September 2020

Globally, studies have shown that diurnal changes in weather conditions and extreme weather events have a profound effect on mortality. Here, we assessed the effect of apparent temperature on all-cause mortality and the modifying effect of sex on the apparent temperature-mortality relationship using mortality and weather data archived over an eleven-year period. An overdispersed Poisson regression and distributed lag nonlinear models were used for this analysis. With these models, we analysed the relative risk of mortality at different temperature values over a 10-day lag period. By and large, we observed a nonlinear association between mean daily apparent temperature and all-cause mortality. An assessment of different temperature values over a 10-day lag period showed an increased risk of death at the lowest apparent temperature (18°C) from lag 2 to 4 with the highest relative risk of mortality (RR = 1.61, 95% CI: 1.2, 2.15, p value = 0.001) occurring three days after exposure. The relative risk of death also varied between males (RR = 0.31, 95% CI: 0.10, 0.94) and females (RR = 4.88, 95% CI: 1.40, 16.99) by apparent temperature and lag. On the whole, males are sensitive to both temperature extremes whilst females are more vulnerable to low temperature-related mortality. Accordingly, our findings could inform efforts at reducing temperature-related mortality in this context and other settings with similar environmental and demographic characteristics.
Two Improved Methods of Generating Adversarial Examples against Faster R-CNNs for Tram Environment Perception Systems
Authors: Huang Shize , Liu Xiaowen , Yang Xiaolu , Zhang Zhaoxin , Yang Lingyu
Published: September 2020

Trams have increasingly deployed object detectors to perceive running conditions, and deep learning networks have been widely adopted by those detectors. Growing neural networks have incurred severe attacks such as adversarial example attacks, imposing threats to tram safety. Only if adversarial attacks are studied thoroughly, researchers can come up with better defence methods against them. However, most existing methods of generating adversarial examples have been devoted to classification, and none of them target tram environment perception systems. In this paper, we propose an improved projected gradient descent (PGD) algorithm and an improved Carlini and Wagner (C&W) algorithm to generate adversarial examples against Faster R-CNN object detectors. Experiments verify that both algorithms can successfully conduct nontargeted and targeted white-box digital attacks when trams are running. We also compare the performance of the two methods, including attack effects, similarity to clean images, and the generating time. The results show that both algorithms can generate adversarial examples within 220 seconds, a much shorter time, without decrease of the success rate.
Coverage Optimization of Sensors under Multiple Constraints Using the Improved PSO Algorithm
Authors: Ling Haifeng , Zhu Tao , He Weixiong , Luo Hongchuan , Wang Qing , Jiang Yi
Published: September 2020

Sensor deployment is an important issue in wireless sensor network (WSN), which is a typical nonlinear system. Conditions of both area coverage and point coverage should be considered in research studies on sensor coverage. It is generally necessary to ensure high coverage ratio of area when controlling sensor locations, and covering specific point targets to ensure long lifetime is also important sometimes. In current studies, swarm intelligence algorithms such as particle swarm optimization (PSO) are widely used to solve the sensor deployment problem in WSN. In this paper, coverage rate and network life indicators are analyzed comprehensively with establishment of a more general K-coverage model. In related calculation examples with different coverage requirements including target coverage, area coverage, and boundary coverage, several improved algorithms based on PSO are applied to solve the problem in the paper. Simulation results show that the improved algorithms can achieve a good performance and deployment effect.
Application of Artificial Intelligence Techniques in Predicting the Lost Circulation Zones Using Drilling Sensors
Authors: Ahmed Abdulmalek , Elkatatny Salaheldin , Ali Abdulwahab , Abughaban Mahmoud , Abdulraheem Abdulazeez
Published: September 2020

Drilling a high-pressure, high-temperature (HPHT) well involves many difficulties and challenges. One of the greatest difficulties is the loss of circulation. Almost 40% of the drilling cost is attributed to the drilling fluid, so the loss of the fluid considerably increases the total drilling cost. There are several approaches to avoid loss of return; one of these approaches is preventing the occurrence of the losses by identifying the lost circulation zones. Most of these approaches are difficult to apply due to some constraints in the field. The purpose of this work is to apply three artificial intelligence (AI) techniques, namely, functional networks (FN), artificial neural networks (ANN), and fuzzy logic (FL), to identify the lost circulation zones. Real-time surface drilling parameters of three wells were obtained using real-time drilling sensors. Well A was utilized for training and testing the three developed AI models, whereas Well B and Well C were utilized to validate them. High accuracy was achieved by the three AI models based on the root mean square error (RMSE), confusion matrix, and correlation coefficient (R). All the AI models identified the lost circulation zones in Well A with high accuracy where the R is more than 0.98 and RMSE is less than 0.09. ANN is the most accurate model with R=0.99 and RMSE=0.05. An ANN was able to predict the lost circulation zones in the unseen Well B and Well C with R=0.946 and RMSE=0.165 and R=0.952 and RMSE=0.155, respectively.
Florid Cemento-Osseous Dysplasia-Associated Simple Bone Cyst Showing Marked Irregular Border and High Apparent Diffusion Coefficient Value
Authors: Kojima Ikuho , Nishioka Takashi , Sakamoto Maya , Sai Yuko , Ezoe Yushi , Iikubo Masahiro , Kumamoto Hiroyuki , Takahashi Tetsu
Published: September 2020

A simple bone cyst (SBC) is an intrabone cavity without epithelial lining, which occasionally occur with fibrous-osseous lesions. The imaging finding of the scalloped border and conserving the lamina dura, periodontal ligament spaces, or follicular spaces are considered radiographically pathognomonic of SBC. SBC has been reported to occur with fibrous-osseous lesions, including cemento-osseous dysplasia (COD). Computed tomography (CT) imaging findings are sparse, and there are no reports of magnetic resonance imaging (MRI) findings, including apparent diffusion coefficient (ADC) value calculated by diffusion-weighted MRI for the florid COD-associated SBC. We report a case of a 39-year-old woman who was referred to our hospital because a panoramic radiograph of her right mandible showed asymptomatic radiolucency in the apical molar area. CT images showed a low-density lesion in the periapical areas of the right mandible, which accompanied a well-defined, high-density lesion, and a mixed low/high-density lesion with an unusual marked irregular border in the left mandible. The MRI showed cyst-like extremely hyperintense signals on fat-suppressed T2-weighted images at the right mandibular low-density and the left mandibular mixed low/high-density areas. ADC map showed high values (over 2.5×10−3 mm2/s) at the cystic areas in the bilateral mandible. We performed incisional biopsies of the bilateral mandibular lesions and resections of the bilateral maxillary lesions. Surgical and histopathological findings established a diagnosis of florid COD in the bilateral mandible and maxilla, simultaneously complicated by multiple SBCs in the bilateral mandible. The ADC value of cystic component is useful for the diagnosis, if the COD-associated SBC exhibits solitary, nonspecific, or rare imaging findings.
Oblivious Inspection: On the Confrontation between System Security and Data Privacy at Domain Boundaries
Authors: Sancho Jorge , García José , Alesanco Álvaro
Published: September 2020

In this work, we introduce the system boundary security vs. privacy dilemma, where border devices (e.g., firewall devices) require unencrypted data inspection to prevent data exfiltration or unauthorized data accesses, but unencrypted data inspection violates data privacy. To shortcut this problem, we present Oblivious Inspection, a novel approach based on garbled circuits to perform a stateful application-aware inspection of encrypted network traffic in a privacy-preserving way. We also showcase an inspection algorithm for Fast Healthcare Interoperability Resources (FHIR) standard compliant packets along with its performance results. The results point out the importance of the inspection function being aligned with the underlying garbled circuit protocol. In this line, mandatory encryption algorithms for TLS 1.3 have been analysed observing that packets encrypted using Chacha20 can be filtered up to 17 and 25 times faster compared with AES128-GCM and AES256-GCM, respectively. All together, this approach penalizes performance to align system security and data privacy, but it could be appropriate for those scenarios where this performance degradation can be justified by the sensibility of the involved data such as healthcare scenarios.
Study on the Ignition Process and Characteristics of the Nitrate Ester Plasticized Polyether Propellant
Authors: Yan Xiaoting , Xia Zhixun , Huang Liya , Ma Likun , Na Xudong , Feng Yunchao , Fang Chuanbo
Published: September 2020

In this study, a CO2 laser ignition experimental system was built to study the ignition process and characteristics of the Nitrate Ester Plasticized Polyether (NEPE) propellant. The effect of the energy density, ingredients, and the grain size distribution of the propellant on the ignition process was investigated using a CO2 laser igniter, a high-speed camera, and a tungsten-rhenium thermocouple. Four types of NEPE propellants were tested under different laser heat fluxes, and the ignition delay time, the ignition temperature, and the ignition energy were obtained. Experimental results show that the ignition process of the NEPE propellant can be divided into three stages, namely the first-gasification stage, the first-flame stage, and the ignition delay stage. When the energy density is lower than the ignition energy threshold, the ignition process cannot be achieved even under continuous energy loading. The increase of the energy density can lead to the decrease of the ignition delay time but has little effect on the ignition temperature. The ingredients and grain size distribution have great effects on both the ignition delay time and the ignition temperature. The grain size effect of aluminum is the largest compared with that of Ammonium Perchlorate (AP) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), while the grain size effect of AP is larger than that of HMX.
Influence of Charge Hole Spacing on the Crack Propagation Behavior under the Effect of Empty‐Hole Directional Blasting
Authors: Tian Guobin , Dai Jun , Wu Yi , Xiong Xianyu , Chen Zhehao
Published: September 2020

In order to explore the reasonable spacing of charge holes in empty‐hole directional blasting, based on the action mechanism of empty‐hole directional blasting, the influence of charge hole spacing on crack propagation is studied, the calculation formula of charge hole spacing is deduced, and the blasting excavation process in Shijiazhuang South Ring Expressway Tunnel is simulated by finite element software. The results show that by setting empty holes on both sides of the charge holes in the peripheral blasting, the guiding cracks can be formed in the connecting direction between the empty hole and the charge hole, the propagation of cracks in other directions can be suppressed, and the spacing of charge holes can be enlarged. Reasonable charge hole spacing is very important to realize the effect of empty‐hole directional blasting; the spacing is small, the rock will be overbroken, and the utilization ratio of explosives is reduced; large spacing, the guiding effect of empty holes is weak, and the effective directional cracks cannot be formed. The spacing between charge holes is closely related to the mechanical properties of rock, detonation parameters of explosive, and aperture of the charge hole and empty hole. According to the simulation results of crack propagation in different spacing, the blasting performance is the best when the charge hole spacing is 800–1000 mm, which is completely consistent with the theoretical calculation result of charge hole spacing 948 mm.
Nonlinear Seismic Response Characteristics of CAP1400 Nuclear Island Structure on Soft Rock Sites
Authors: Li Furong , Chen Guoxing
Published: September 2020

CAP1400 nuclear island structure is an advanced and novel nuclear power plant structure. In order to explore the seismic response characteristics of CAP1400 nuclear island structure on soft rock sites, a three-dimensional refined nonlinear seismic response analysis model was established for a soft rock foundation-nuclear island structure system using ABAQUS software. The influences of the input ground motion intensity and the frequency spectrum characteristics on the acceleration, relative displacement, and floor response spectrum, as well as the critical shear wave velocity of nonbedrock sites for CAP1400 nuclear island structure, were proposed. The results suggested that the increasing amplitude of the peak acceleration and relative displacement of nuclear island structure decreased as the soft rock site entered a nonlinear state, and the high-frequency components of the input ground motion became more abundant. Specifically, the earthquake response was the largest at the cooling water tank on the top of the shield building, which was the focus of the seismic research on nuclear island structure. Due to the influence of the ground motion frequency spectrum characteristics and the nonbedrock site effect, the peak acceleration, peak relative displacement, and acceleration response spectrum of the nuclear island structure showed different changing trends for the near-field and far-field ground motions. Based on the influence of the site shear wave velocity on the seismic response of nuclear island structure, it was recommended that the critical shear wave velocity of nonbedrock sites for CAP1400 nuclear island structure should be 1250 m/s, and the nuclear island structure-foundation dynamic interaction could be ignored at this time. The research conclusions could provide some technical support and theoretical basis for the construction and seismic performance research of CAP1400 and other nuclear power plants.
Towards an Improved Energy Efficient and End-to-End Secure Protocol for IoT Healthcare Applications
Authors: Ahmad Arshad , Ullah Ayaz , Feng Chong , Khan Muzammil , Ashraf Shahzad , Adnan Muhammad , Nazir Shah , Khan Habib Ullah
Published: September 2020

In this paper, we proposed LCX-MAC (local coordination X-MAC) as an extension of X-MAC. X-MAC is an asynchronous duty cycle medium access control (MAC) protocol. X-MAC used one important technique of short preamble which is to allow sender nodes to quickly send their actual data when the corresponding receivers wake up. X-MAC node keeps sending short preamble to wake up its receiver node, which causes energy, increases transmission delay, and makes the channel busy since a lot of short preambles are discarded, as these days Internet of Things (IoT) healthcare with different sensor nodes for the healthcare is time-critical applications and needs a quick response. A possible improvement over X-MAC is that local information of each node will share with its neighbour node. This local information exchanged will cause much less overhead than in the nodes which are synchronized. To calculate the effect of this the local coordination on X-MAC in this paper, we built an analytical model of LCX-MAC that incorporates the local coordination in X-MAC. The analytical results show that LCX-MAC outperformed X-MAC and X-MAC/BEB in terms of throughput, delay, and energy.
A Robust Image Watermarking Approach Using Cycle Variational Autoencoder
Authors: Wei Qiang , Wang Hu , Zhang Gongxuan
Published: September 2020

With the rapid development of Internet and cloud storage, data security sharing and copyright protection are becoming more and more important. In this paper, we introduce a robust image watermarking algorithm for copyright protection based on variational autoencoder networks. The proposed image watermarking embedding and extracting network consists of three parts: encoder subnetwork, decoder subnetwork, and detector subnetwork. In the training process, the encoder and decoder subnetworks learn a robust image representation model and further implement the embedding of 1-bit watermark image to the cover image. Meanwhile, the detector subnetwork learns to extract the 1-bit watermark image from the embedding image. Experimental results demonstrate that the watermarked images generated by the proposed algorithm have better visual effects and are more robust against geometric and noise attacks than traditional approaches in the transform domain.
Effects of Mating and Social Exposure on Cell Proliferation in the Adult Male Prairie Vole (Microtus ochrogaster)
Authors: Castro A. E. , Young L. J. , Camacho F. J. , Paredes R. G. , Diaz N. F. , Portillo W.
Published: September 2020

Microtus ochrogaster is a rodent with a monogamous reproductive strategy characterized by strong pair bond formation after 6 h of mating. Here, we determine whether mating-induced pair bonding increases cell proliferation in the subventricular zone (SVZ), rostral migratory stream (RMS), and dentate gyrus (DG) of the hippocampus in male voles. Males were assigned to one of the four groups: (1) control: males were placed alone in a clean cage; (2) social exposure to a female (SE m/f): males that could see, hear, and smell a sexually receptive female but where physical contact was not possible, because the animals were separated by an acrylic screen with small holes; (3) social exposure to a male (SE m/m): same as group 2 but males were exposed to another male without physical contact; and (4) social cohabitation with mating (SCM): males that mated freely with a receptive female for 6 h. This procedure leads to pair bond formation. Groups 2 and 3 were controls for social interaction. Male prairie voles were injected with 5-bromo-2′-deoxyuridine (BrdU) during the behavioral tests and were sacrificed 48 h later. Brains were processed to identify the new cells (BrdU-positive) and neuron precursor cells (neuroblasts). Our principal findings are that in the dorsal region of the SVZ, SCM and SE m/f and m/m increase the percentage of neuron precursor cells. In the anterior region of the RMS, SE m/f decreases the percentage of neuron precursor cells, and in the medial region SE m/f and m/m decrease the number of new cells and neuron precursor cells. In the infrapyramidal blade of the subgranular zone of the DG, SE m/m and SCM increase the number of new neuron precursor cells and SE m/m increases the percentage of these neurons. Our data suggests that social interaction, as well as sexual stimulation, leads to pair bonding in male voles modulating cell proliferation and differentiation to neuronal precursor cells at the SVZ, RMS, and DG.
A Novel IM Sync Message-Based Cross-Device Tracking
Authors: Guo Naixuan , Luo Junzhou , Ling Zhen , Yang Ming , Wu Wenjia , Gu Xiaodan
Published: September 2020

Cybercrime is significantly growing as the development of internet technology. To mitigate this issue, the law enforcement adopts network surveillance technology to track a suspect and derive the online profile. However, the traditional network surveillance using the single-device tracking method can only acquire part of a suspect’s online activities. With the emergence of different types of devices (e.g., personal computers, mobile phones, and smart wearable devices) in the mobile edge computing (MEC) environment, one suspect can employ multiple devices to launch a cybercrime. In this paper, we investigate a novel cross-device tracking approach which is able to correlate one suspect’s different devices so as to help the law enforcement monitor a suspect’s online activities more comprehensively. Our approach is based on the network traffic analysis of instant messaging (IM) applications, which are typical commercial service providers (CSPs) in the MEC environment. We notice a new habit of using IM applications, that is, one individual logs in the same account on multiple devices. This habit brings about devices’ receiving sync messages, which can be utilized to correlate devices. We choose five popular apps (i.e., WhatsApp, Facebook Messenger, WeChat, QQ, and Skype) to prove our approach’s effectiveness. The experimental results show that our approach can identify IM messages with high F1-scores (e.g., QQ’s PC message is 0.966, and QQ’s phone message is 0.924) and achieve an average correlating accuracy of 89.58% of five apps in an 8-people experiment, with the fastest correlation speed achieved in 100 s.
Immovable Cultural Relics Disease Prediction Based on Relevance Vector Machine
Authors: Liu Bao , Mu Kun , Ye Fei , Deng Jun , Wang Jingting
Published: September 2020

The preventive cultural relics protection is one of the most concerned contents in archaeology, which includes environmental monitoring and accurate prediction of cultural relics diseases. In view of the deficiency of the analysis of cultural relics data and the prediction of cultural relics diseases, a prediction model of immovable cultural relics diseases based on relevance vector machine (RVM) is proposed. The key factors affecting the disease of immovable cultural relics are found out by the principal component analysis method, and the dimension reduction of data is realized; then, the RVM model under the framework of Bayesian theory is constructed, and the super parameters are estimated by the maximum edge likelihood method; finally, the prediction accuracy of the model is compared with the traditional diseases prediction methods. The experiment results demonstrate that the proposed RVM-based immovable cultural relics disease prediction approach not only has the advantages of more sparse model but also has better prediction accuracy than the traditional radial basis function neural network-based and support vector machine-based methods.