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Many soft robots are made of hyperelastic silicone rubbers and usually experience large nonlinear deformations in actions. Accurate material parameters are essential to provide reliable analysis and support robot designs. This letter presents a practical material parameter determination method by iteratively fitting the force-displacement curves measured from two biaxial tension and one uniaxial tension specimens. It reveals the insufficient constraint of one biaxial and one uniaxial test data towards the correct set of material coefficients. Based on three specimens, the material parameter obtained leads to high consistency with the bending validations of four soft fingers, demonstrating the proposed method is capable to accurately determine material properties for hyperelastic soft structures and can be readily used in soft robot designs and analysis.

Students using a Learning Management System (LMS) as a learning support have been observed to demonstrate different learning behaviours. Studies have reported students exhibiting different procrast...

To solve the problem of manpower and time consumption caused by power flow state adjustment in a large-scale power grid, a power system operation state adjustment method considering the static stability constraint based on parallel deep reinforcement learning is proposed. By introducing the process of adjusting the power flow state that satisfies static stability, the Markov decision-making process of adjusting power flow is constructed. Then, based on the positioning of the adjustment target, the selection of actionable devices and the calculation of the amount of action, a power flow state adjustment strategy is developed. The adjustment process is accelerated through sensitivity, transfer ratio and load margin. Then, a parallel deep reinforcement learning model is established, and it maps actions to power flow adjustment to form a pair of generator actions and realises parallel adjustment of multi-sectional objectives. In addition, the reinforcement learning strategy and the deep learning network are improved to promote learning efficiency. Finally, the New England 39-bus standard system and actual power grid are used to verify the effectiveness of the method.

Severe pneumonia which shares several of the features of acute respiratory distress syndrome (ARDS) is the main cause of morbidity and mortality in Coronavirus disease 19 (Covid-19) for which there is no effective treatment, so far. ARDS is caused and sustained by an uncontrolled inflammatory activation characterized by a massive release of cytokines (cytokine storm), diffuse lung oedema, inflammatory cell infiltration, and disseminated coagulation. Macrophage and T lymphocyte dysfunction plays a central role in this syndrome. In several experimental in vitro and in vivo models, many of these pathophysiological changes are triggered by stimulation of the P2X7 receptor. We hypothesize that this receptor might be an ideal candidate to target in Covid-19-associated severe pneumonia. LINKED ARTICLES: This article is part of a themed issue on The Pharmacology of COVID-19. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.21/issuetoc.

Background: A large number of studies have been conducted to investigate associations between genetic variants and esophageal cancer risk in the past several decades. However, findings from these studies have been generally inconsistent. We aimed to provide a summary of the current understanding of the genetic architecture of esophageal cancer susceptibility. Methods: We performed a comprehensive field synopsis and meta-analysis to evaluate associations between 95 variants in 70 genes or loci and esophageal cancer risk using data from 304 eligible publications, including 104,904 cases and 159,797 controls, through screening a total of 21,328 citations. We graded levels of cumulative epidemiologic evidence of a significant association with esophageal cancer using the Venice criteria and false-positive report probability tests. We constructed functional annotations for these variants using data from the Encyclopedia of DNA Elements Project and other databases. Results: Thirty variants were nominally significantly associated with esophageal cancer risk. Cumulative epidemiologic evidence of a significant association with overall esophageal cancer, esophageal squamous cell carcinoma, or esophageal adenocarcinoma was strong for 13 variants in or near 13 genes (ADH1B, BARX1, CDKN1A, CHEK2, CLPTM1L, CRTC1, CYP1A1, EGF, LTA, MIR34BC, PLCE1, PTEN, and PTGS2). Bioinformatics analysis suggested that these variants and others correlated with them might fall in putative functional regions. Conclusions: Our study summarizes the current literature on the genetic architecture of esophageal cancer susceptibility and identifies several potential polymorphisms that could be involved in esophageal cancer susceptibility. Impact: These findings provide direction for future studies to identify new genetic factors for esophageal cancer.

A general methodology for the dynamics of spacecraft with rigid–liquid–flexible body coupling is established by using Kane’s equations, whereby the combined sloshing in multiple tanks and the dynam...

AIM: To investigate the safety and efficacy of sticky silicone oil (SSO) removal using a 22-gauge vein detained needle and inner limiting membrane (ILM) wrap-and-peel technique. METHODS: This retrospective consecutive case series reviewed the records of patients with a history of retinal detachment who had received silicone oil and perfluorocarbon liquid (PFCL) as intraocular tamponades. Patients were included in the analysis if they exhibited SSO remnants during silicone oil removal. The aspiration of most of the SSO remnants was performed by a 22-gauge vein detained needle. The small amounts of droplets adhered to the macula and epi-macular membrane were subsequently removed by the ILM warp-and-peel technique. The anatomical and functional outcomes, and postoperative complications were recorded. In vitro experiments were performed to simulate the formation of SSO remnants in four groups. RESULTS: Of 711 patients who underwent silicone oil removal during the study period, 9 patients exhibited SSO remnants and underwent follow-up for at least 3mo. Seven eyes (78%) underwent the ILM wrap-and-peel technique to completely remove small droplets of SSO that were glued to the macula and epi-macular membrane. No obvious complications occurred. Postoperative optical coherence tomography revealed normal retinal structure in all patients. In vitro analyses showed that balanced salt solution and prolonged vibration (for 1wk) had the strongest effects on silicone oil and PFCL compound opacities. CONCLUSION: SSO remnants could be removed in an intact manner and without complications, using a vein detained needle-assisted and ILM wrap-and-peel technique. The findings suggest that PFCL and infusion fluid should be completely removed before silicone oil injection to prevent SSO formation.

Background: Acute coronary syndrome (ACS) is a group of clinical syndromes caused by thrombosis caused by rupture of coronary atherosclerotic plaque or erosion ulcer, resulting in complete or incomplete occlusion of blood vessels. ACS is the most common cardiovascular critical disease. Although with the development of coronary intervention technology, the incidence of major adverse cardiovascular events (MACE) is still high. In China, traditional Chinese medicine (TCM) has been widely used in the adjuvant treatment of ACS to improve the symptoms and prognosis. Danhong injection (DHI) and Naoxintong capsule (NXTC) may improve the prognosis of patients with ACS, but the evidence-based evidence is still insufficient. The main purpose of this study was to evaluate the efficacy and safety of DHI combined with NXTC in the treatment of ACS.Methods/design:This is a randomized, placebo-controlled clinical trial.1752 patients with ACS undergoing percutaneous coronary intervention (PCI) will be randomly assigned to receive DHI combined with NXTC or placebo at the ratio of 1:1. The course of treatment was 12 weeks. All participants received conventional treatment. The main outcome measure was the 12-months incidence of MACEs. Adverse events (AE) will also be evaluated.Discussion:This trial is a well designed study according to principles and regulations issued by the China food and Drug Administration (CFDA). The results will provide high-quality evidence for the efficacy and safety of DHI combined with NXTC in the treatment of ACS. The results of this study can provide clinicians with evidence-based recommendations for treatment of ACS.Trial registration：Chinese Clinical Trial Registry(http://www.chictr.org.cn/index.aspx), ChiCTR-IOR-14005693.Registered on November 12,2014.

Excessive pesticide residues are a serious problem faced by food regulatory authorities, suppliers, and consumers. To assist with this challenge, this work aimed to develop a method of detecting and classifying pesticide residue on fruit samples using an electronic nose, through the application of three different data-recognition algorithms. The apple samples carried various concentrations of two known pesticides, namely cypermethrin and chlorpyrifos. Data collection was performed using a PEN3 electronic nose equipped with 10 metal oxide semiconductor (MOS) sensors. In order to classify and analyze these pesticide residues on the apple samples, principal component analysis (PCA), linear discriminant analysis (LDA), and support vector machine (SVM) results were combined with sensor output responses to realize MOS sensor array data visualization. The results indicated that all three data-recognition algorithms accurately identified the pesticide residues in the apple samples, with the PCA algorithm exhibiting the best classification and discrimination ability. Consequently, this work has shown that the MOS electronic nose, in combination with data-recognition algorithms, can provide support for the rapid and non-destructive identification of pesticide residues in fruits and can provide an effective tool for the detection of pesticide residues in agricultural products.

Background. This study aims to determine the analgesic effect and safety of dexmedetomidine as an adjuvant to epidural local anesthetics during labor. Methods. Randomized controlled trials comparing epidural blocks with or without dexmedetomidine for labor analgesia were comprehensively searched. Review manager 5.4 was used to analyze the extracted data. Results. Compared with placebo and opioids, dexmedetomidine relieved labor pain of 15 min ( P = 0.002 ), 30 min ( P = 0.01 ), and 120 min ( P = 0.02 ) after block and at the moment of fetal disengagement ( P = 0.0002 ), decreased mean arterial pressure of 120 min ( P = 0.01 ), heart rate of 30 min ( P = 0.003 ), 60 min ( P < 0.00001 ), and 120 min ( P < 0.00001 ) after block, blood loss ( P = 0.02 ), and the incidence of nausea/vomiting ( P = 0.006 ), and increased the incidence of maternal bradycardia ( P = 0.04 ). However, sensitivity analysis only found that the incidence of nausea/vomiting was significantly different. Compared with placebo, dexmedetomidine relieved labor pain of 30 min after block ( P < 0.00001 ) and did not increase the incidences of side effects, but only two studies were enrolled. Compared with opioids, dexmedetomidine decreased the incidence of nausea/vomiting ( P = 0.002 ), increased the incidence of maternal bradycardia ( P = 0.04 ), and had a similar effect on labor pain relief; however, sensitivity analysis found that significant difference existed only at the incidence of nausea/vomiting. Other outcomes from meta-analysis or subgroup analysis were not different. Conclusions. Epidural dexmedetomidine has the potential to offer a better analgesic effect than placebo, similar labor pain control to opioids, and has no definite adverse effects on the parturient or fetus, but more high-quality studies are needed to confirm these conclusions.

Based on the idea of modular design of ship, the ship modular method is used to study the target cost of ship repair, and a modular decomposition and analysis method of ship repair cost is proposed to decompose the ship repair project into relatively independent sub-modules, standardizes the repair scope of sub modules, determines the repair cost standard of sub-modules, and accumulates the repair cost of corresponding sub-modules. At the same time, from the perspective of cost control, cost risks are identified, and the fuzzy analytic hierarchy process is applied to analyze and evaluate risk factors to lay the foundation for cost adjustment and cost reduction risks.

Purpose: To determine the efficacy of acupuncture on the management of hormone therapy–related side effects in breast cancer patients. Methods: Randomized controlled trials of acupuncture versus a control or placebo in breast cancer patients that examined reductions in therapy-related side effects were retrieved from PubMed, EMBASE, Web of Science, and the Cochrane Library through April 2020. Data on patient symptoms (hot flashes, fatigue, pain, stiffness, and gastrointestinal symptoms), physical capacity, cytokines, and general psychosomatic well-being were analyzed. We evaluated and analyzed the quality of all included studies with the 5.2 Cochrane Handbook standards using Stata software (version 10.0) and Revman software (version 5.2), respectively. We assessed the risk of bias using the Cochrane Risk of Bias tool and evaluated the quality of evidence using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) approach. Results: The pooled results suggested that acupuncture led to moderate improvements in hot flashes, fatigue, and stiffness. No significant differences were observed in pain, gastrointestinal symptoms, Kupperman index scores, Overall quality of life, tumor necrosis factor levels, and interleukin levels. Conclusions: Evidence for outcome indicators of symptom management were downgraded by the GRADE system for inconsistency, indirectness, and imprecision in the included RCTs. Nonetheless, acupuncture is a moderately appropriate alternative therapy for hormone therapy–related side effects in breast cancer patients. However, it still lacks large-sample, multicenter, prospective RCTs. Future research should focus on standardizing comparison groups and treatment methods, be at least single-blinded, assess biologic mechanisms, have adequate statistical power, and involve multiple acupuncturists.

The CGN Taishan NPP seawater storage is a land-sealed type and is connected to the open water intake channel of Dajin Island in the open sea through a subsea tunnel. Due to the impact of large-scale facility aquaculture in the nearby seas, fish spawning grounds have been formed in this area, and fish breeds faster. A large number of fish have impacted on safe operation of nuclear power. In response to this situation, this study conducted acoustic navigation surveys of fish resources in most waters of the “Sea Reservoir” and “Water intake channel”, using broadband scientific fish finder system (EK80, 120kHz, 200kHz) produced by Norwegian Simrad Company. Evaluation of acoustic resources using echo integration method. The survey scope of seawater storage in this survey is from the entrance to the first barrier (around a distance of 760m) and from the first barrier to a second barrier (around a distance of 220m); the survey distance of the water intake channel is about 1460m. From the echo image, it can be found that the zooplankton in the sea reservoir is much smaller than the water intake channel, and the fish size of the water intake channel is much larger than that of the sea channel.Acoustic data was processed and analyzed using Echoview software to calculate the average SV and detect the strength of the single target. The results show that in the survey area of the Taishan Nuclear Power Plant Hai Reservoir, the total number of fish is about 1.38 million, the total weight is about 13.6 tons, and the fish with a body length of less than 20cm is the majority, and there are fewer large-sized fish; The total resources in the survey area is about 47 tons, with a total number of 27 million, and has a high density.

Insulated Gate Bipolar Transistor (IGBT) has different power consumption-temperature characteristics in different temperature stages. Based on the existing steady-state and transient mathematical models of IGBT, the power consumption-temperature curve of IGBT is obtained by considering the relationship between the internal parameters of the device and the physical constants of the material semiconductor and temperature. It is found that the power consumption-temperature curve increases approximately linearly in the low temperature stage and exponentially in the high temperature stage. The stable point, unstable point and critical point of junction temperature are obtained by solving the IGBT power consumption-temperature curve and heat transfer curve simultaneously, and the thermal failure mechanism of IGBT is analyzed based on the positive feedback relationship between IGBT power consumption and junction temperature at the unstable point. Finally, the experimental verification is carried out.

Enterprise information system may be threatened and attacked at any time from the external and internal environment, so how to improve the enterprise information system from the outside world unknown threat detection is particularly important. This paper is based on the method that is applied to detecting and identifying unknown threat, so as to protect and improve the information system’s safety and stability with technical support and guarantee. It can avoid the impact of unknown threat on information system security to the greatest extent.

In the application process of industrial Internet, network security threats and malicious attacks occur from time to time. In order to improve the ability of network perception of unknown threats and the level of network security protection, this paper proposes a network security detection method based on full flow. Through online intelligent detection of network malicious traffic, unknown threats and malicious attacks can be found, provide guarantee for improving enterprise network security level.

This study investigates the contrasting sceneries of community-based tourism after the 2008 Wenchuan earthquake and focuses on the potentials of tourism in transformations towards green economies. How are tourism and environment linked in a sustainable relationship? And how can potentials of community-based tourism be directed in transformations towards green economies? A qualitative research design is used to examine contrasting sceneries and specific green elements of community-based tourism in a Qiang people's fortress village in Mao County, Sichuan Province, West China and further discuss how tourism can be compatible with human wellbeing through demonstrating a commitment to sustainable development. The study argues that potential economic, social and environmental costs of tourism need to be considered when evaluating the loss of community benefits toward sustainability. The green elements suggest the potential of community-based tourism in transformations towards green economies, involving green agricultural, green building, and green energy, green governance, green service and green consumption. This study will contribute to the debate about the relationship between tourism and environment sustainability in the green economies, as well as the critique of what can be learned for community development from green tourism in mountainous regions after the inevitable natural disasters.

Some of the defects of community detection algorithms in complex networks include pre-parameter limits and redundant labels. Accordingly, we present an improved overlapping community detection algorithm in complex networks that is a minimal maximal clique label propagation algorithm (MMCLPA). The algorithm uses the minimal maximal clique (MMC), and allows each MMC to share the same label by reducing redundant labels and random factors. Therefore, the MMCLPA algorithm increases the stability of the algorithm. Mean-while, the MMCLPA algorithm completes label propagation from core node groups (MMC) for distribution using intimacy as the weight of the label. For the labels post processing, uses adaptive threshold method to overcome pre-parameter limitations in unknown complex networks. When compared with other community detection al-gorithms using arti cial and real network data, our experiment results prove that the MMCLPA algorithm not only increases the tolerance for mixing parameters, but also improves the robustness of the algorithm. Lastly, by employing a distributed computing model (Map Reduce) and cloud platform (Hadoop), we allow parallelization implementation of MMCLPA. Our experiment results show that parallel MMCLPA owns an approximation of quality compared with the stand-alone system, as well as better scalability.

In this paper, Insulated Gate Bipolar Transistor (IGBT), which is the most widely used full-control power electronic device, is taken as the research object. Under the special working mode of short-time intermittent pulse, with the increase of conduction current, the chip junction temperature of high-power IGBT will rise sharply and fluctuate greatly, causing the operating characteristics of the device to be greatly affected by temperature. The commonly used method of measuring the bottom plate shell temperature with thermocouples and then estimating the steady junction temperature can no longer meet the demand. Firstly, the fluctuation characteristics of junction temperature of high-power IGBT are analyzed. Then, a high-speed infrared thermal imaging device is used to carry out real-time junction temperature detection. The distribution and rising process of instantaneous junction temperature on the chip surface are obtained, which further verifies the correctness of theoretical analysis. The research has important guiding significance for IGBT application design under short-time intermittent pulse operation mode, and also has certain reference value for general operation mode.

Dry eye disease (DED) is a multifactorial disease of the tear film and ocular surface that causes symptoms of discomfort, visual disturbances and instability of the tear film. It is accompanied by an increase in tear film osmolarity and ocular surface inflammation. The global prevalence of Dry Eye Disease (DED) ranged from 5% to 50%, accompanied by the yearly increasing trend and younger onset. However, the condition remains incompletely understood and treated. DED symptom severity significantly correlates with deficits in physical, psychological, and social well-being, with the most severely affected patients reporting the worst scores for all aspects of health-related quality of life. DED symptoms and reduced visual function affect vision-dependent daily activities, with consequential negative impacts on social and physical functioning, workplace productivity, and quality of life. Furthermore, patients with DED report significantly higher rates of anxiety and depression compared with the general population, and significantly higher rates of sleep and mood disorders compared with other ocular conditions, which may exacerbate productivity, performance of personal tasks, and overall well-being. At present, there is no fully curable modality for DED. Artificial tear serves as a mainstay therapy for DED management. In fact, acupuncture has an outstanding effects in treating several diseases, including DED. Clinical study indicated that acupuncture could improve mid-term outcome compared to artificial tears. However, acupuncture is not recommended as a complementary therapy in the latest management guidelines of DED. We therefore think, it is necessary to conduct a comprehensive review of the latest research on the effects of acupuncture vs. artificial tears on DED treatment, with the aim to explore whether acupuncture deserves to be recommended as an adjunct therapy for DED.

To realize lightweight design of the fuel cell system is a critical issue before it is put into practical use. The printed-circuit-board (PCB) technology can be potentially used for production of current collectors or flow distributors. This study develops prototypes of a single passive air-breathing direct methanol fuel cell (DMFC) and also an 8-cell mono-polar DMFC stack based on PCB current collectors. The effects of diverse structural and operational factors on the cell performance are explored. Results show that the methanol concentration of 6 M promotes a higher cell performance with a peak power density of 18.3 mW cm −2 . The combination of current collectors using a relatively higher anode open ratio and inversely a lower cathode open ratio helps enhance the cell performance. Dynamic tests are also conducted to reveal transient behaviors and its dependence on the operating conditions. To validate the real working status of the DMFC stack, it is coupled with an LED lightening system. The performance of this hybrid system is also reported in this study.

Vehicle detection and type recognition based on static images is highly practical and directly applicable for various operations in a traffic surveillance system. This paper will introduce the processing of automatic vehicle detection and recognition. First, Haar-like features and AdaBoost algorithms are applied for feature extracting and constructing classifiers, which are used to locate the vehicle over the input image. Then, the Gabor wavelet transform and a local binary pattern operator is used to extract multi-scale and multi-orientation vehicle features, according to the outside interference on the image and the random position of the vehicle. Finally, the image is divided into small regions, from which histograms sequences are extracted and concentrated to represent the vehicle features. Principal component analysis is adopted to reach a low dimensional histogram feature, which is used to measure the similarity of different vehicles in euler space and the nearest neighborhood is exploited for final classification. The typed experiment shows that our detection rate is over 97 %, with a false rate of only 3 %, and that the vehicle recognition rate is over 91 %, while maintaining a fast processing time. This exhibits promising potential for implementation with real-world applications.

Summary This paper presents a synergetic approach based on a statistical-empirical method, conservation of energy method and superstructure-foundation interaction theory, and this paper aims to estimate the deformation level of a compensated piled raft foundation. The advantages and main characteristics of such a compensated piled raft foundation are described, and a history of the heave, recompression deformation and final settlement data measurements is provided. Case studies of four super-tall buildings, the 88-story Jinmao Building, 66-story Henglong Plaza, 101-story Shanghai World Financial Center and 121-story Shanghai Center Tower in Shanghai, all of which are engineering projects that the second author participated in, are provided to illustrate the effectiveness of different calculations for heave, recompression deformation and final settlement. This study demonstrates that the deformation process can be reasonably projected for a piled raft foundation with deep embedment in Shanghai using superstructure-foundation interaction methods, statistical-empirical formulas and a method based on the conservation of energy. The coefficients in the statistical-empirical method are also further optimized. This deformation estimation considering compensation for deep embedment unloading is reasonable and can be used to avoid excessively conservative designs, and the synergetic approach is applicable to any compensated piled raft foundation with deep embedment in Shanghai. Copyright © 2014 John Wiley & Sons, Ltd.

Introduction In traditional Chinese medicine, the same disease is treated with different methods based on syndrome differentiation. Endotoxic shock is treated with Shenfu injection or Niupo Zhibao pellet according to “Heat Block Syndrome” or “Yang Collapse Syndrome”. This study aimed to investigate the molecular mechanisms of two different treatments used for endotoxic shock – Shenfu Injection and Niupo Zhibao pellet. Methods The names of genes related to Shenfu injection, Niupo Zhibao pellet and endotoxic shock were extracted from PubMed through literature mining. Pathway and protein–protein interaction network analysis were applied to these genes to compare the functions of Shenfu injection and Niupo Zhibao pellet. Results Though Niupo Zhibao pellet and Shenfu injection are different treatments, they have common functions as they are treating the same disease. The two treatments both regulate the inflammation-related signaling pathway to interfere with the inflammation cascade. Meanwhile, the two treatments aim at different syndromes. The treatment with Niupo Zhibao pellet for endotoxic shock with “Heat Block Syndrome” may eliminate pathogenic factors through regulating activity of ubiquitin-protein ligase. The treatment with Shenfu injection for endotoxic shock with “Yang Collapse Syndrome” may restore Yang to save from collapse through the renin–angiotensin system, immune system, and hormone-mediated cellular signal transduction. Conclusion The molecular mechanisms of Shenfu injection and Niupo Zhibao pellet reveal the biological basis of different treatments for endotoxic shock. This may help to integrate TCM with western medicine and improve treatment efficacy for endotoxic shock.

According to the Chinese power network planning, the risk of voltage instability at the receiving-end AC power system will be increased significantly, where there will be more HVDC systems feeding into a same AC grid in the future. At present, the effective voltage stability analysis methods of multi-infeed DC (MIDC) system are few, the most widely used method with most research results is the multi-infeed short-circuit ratio (MISCR) index at home and abroad. The deficiency of MISCR index is pointed out. The relationship between multi-infeed interaction factor (MIIF) and the voltage stability of the receiving-end AC system is discussed. Then a new method joint MIIF and MISCR indexes to evaluate the voltage stability of MIDC system is put forward. Finally, simulation tests and analysis results of a large actual grid prove the feasibility and good performance of the proposed new method.

With the development of power electronics technology, the capacity of power conversion devices is getting larger and larger, and the current level requirements for high-power IGBT are also getting higher and higher. A single device often cannot meet the requirements, and multiple IGBT need to be used in parallel. When IGBT is connected in parallel, due to the differences in device parameters, external circuit parameters and heat dissipation conditions, the current distribution is easily unbalanced, resulting in device performance waste or even damage. Therefore, the current sharing problem is the core problem to be solved in parallel connection of IGBT. In order to solve the problems such as difficulty in analyzing a single factor for coupling of various influencing factors, difficult control of temperature and high cost of circuit, this paper adopts Saber software simulation method to analyze the influence of various internal and external factors on IGBT’s dynamic and static current sharing, thus obtaining the relationship between these factors and corresponding countermeasures, and obtaining an effective IGBT parallel current sharing scheme. Finally, the correctness and effectiveness of this scheme are verified by experiments.

By observing the same GPS receiver, getting positioning data of 1000 sets of GPS and DGPS each, the two groups of data were calculated by utilizing the probability and statistics, and the average position of the two was GPS: 38°52′. 111N, 121°33′.029E, DGPS:38°52′.107N, 121°33′.033E, 95% of mean square error circle radius of GPS respectively 6.975015372m, DGPS:3.267239581m. By comparison, the positioning accuracy of DGPS is more than twice that of GPS.

In the ad hoc network, the unfairness of the system will affect the quality of service seriously. This paper proposed a new algorithm---FBGT, the algorithm use successfully send rate as measurement parameter, and use the Nash equilibrium of game theory as each flow transmission probability. The algorithm calculate every flow’s successfully send rate, and then exchange with the neighbor nodes, combing with the node's own information and neighbor node information to determine the backoff time to improve the system fairness. Due to FBGT algorithm taking into account the system’s local and global fairness and throughput, experimental analysis and data simulation showed the system's fairness index has been increased by 10% - 15%, the throughput of the system has also been improved to a certain degree.

A high accurate optical head pose tracker system based on multiple-cameras was investigated to track the high accurate head pose of a virtual reality system.A calibration square was designed to eliminate the system installation error to allow the optical axis of a camera to be perpendicular every two cameras.In positioning,the depth value of the object was given arbitrarily by taking a camera for a criterion,then,other coordinate values could be generated by a camera model.The obtained results were taken as the initial depth and used in the loop iteration to compute the object's position.At last,the object pose could be calculated based on the position of three markers.Comparative experiments show that the algorithm has high accuracy and rapid convergence.The static error is 0.51 mm,and the dynamic tracking error is 0.88 mm,which is significantly higher than that of the electromagnetic tracker system.Meanwhile,the positioning system has low-cost and can not be disturbed by metal or electromagnetic environments.It can meet the high-precision position tracking requirements of virtual reality systems.

In practice, the two-dimensional TDOA source location in the case of three stations would encounter the ambiguity problem of dual solutions. The relationship between distributions of location curve intersections, GDOP and receiving station layout is numerically analyzed, namely the distributions of location curve intersections and GDOP are determined by the receiving station layout, and the areas of two curve intersections are consistent with these of larger GDOP. These analysis results could serve as reference for avoiding or dealing with the ambiguity problem when multilateration is in application.

This paper presents the requirement,chanllage and architecture for service-oriented scholar information service in cloud computing environment.In particular,we propose ScholarCloud platform for scholar information service,and give innovative example about software technology to build scholar information application within ScholarCloud Environment. The result shows service-oriented ScholarCloud platform has potential to help scholar individual,academic team or institute to build scholar information spaces.

Under the construction of smart grid, transmission grid investment is faced with many potential risks, and high flexibility of decision-making is asked. Based on technology readiness theory, stage financing issues for transmission grid investment are studied. Then transmission grid investment is divided into several stages, and in order to form an optimal investment scheme and find reasonable fund for each stage, a decision-making model for transmission grid investment based on technology readiness is established. The model is validated through three-stage transmission grid investment project in IEEE-24 bus system, to consider the optimal investment decision between transmission lines and TCSC devices.

A fast local feature description algorithm based on the region histogram of Greyvalue Differential Invariants(GDIs) is presented to improve the traditional GDI feature descriptor with complex computation,worse stability and less information.The GDIs with the meaning of differential geometry derived from low order derivatives are used to describe a feature point to reduce the computation complexity of the feature descriptor and enhance the stability.The intensity and relative location of the feature point neighborhood are made full use of to increase the content of information and improve the robustness of the feature descriptor.Finally,the feature description is used to match images.The experiment results demonstrate that the proposed algorithm can get better matching results in the cases of image zoom,rotation,blurring,illumination varying,smaller viewpoint changes as well as JPEG compression.Furthermore,the processing speed is about twice that of the Scale Invariable Feature Transform(SIFT).

A high-performance regulation and control method was designed for photovoltaic grid-connected system. To meet the basic requirement, a new special frequency and phase measurement by using two-way square wave cycle and the improvement in Amplitude-Limiter-Filter algorithm to reach the target accuracy were utilized. The related experiment results showed that the system in which this method was adopted work stably.

As the software industry develops rapidly, protecting software intellectual property from reverse attacker has become more and more important. The technical way is to make software hard to understand and will cost attackers more time and energy to crack the software than they can take. Self-modifying code is a code changing mechanism based on stored program architecture and has been widely used in software protection methods these years. This article introduces four different kinds of software protection methods using self-modifying code, and classifies the features of the implementation. The protection intensity and overheads are evaluated respectively. This article also compares the advantages and drawbacks of each method, and makes conclusions about the developing trends of software protection technologies.

In order to balance the robustness and building complexity of a feature descriptor,a local feature description algorithm based on Laplacian is presented.It is analyzed and illustrated that the Laplacian not only has good properties to Euclidian transformation,zoom,and linear brightness changes of an image,but also can characterize the local structure of the image.On the basis of that,a 64-dimension descriptor is built with the response of Laplacian of Gaussian.Finally,the descriptor is used to match feature points with the absolute distance as similarity measurement.Simulation results indicate that the proposed descriptor can obtain better matching results for the image with zoom,rotation,blurring,illumination varying as well as smaller viewpoint changes,and the matching speed is more than 4 times that of Scale Invariable Feature Transformation(SIFT).The proposed feature description algorithm is suitable for matching the images of structured scenes,for it is insensitive to the image transformation with rotation,zoom,luminance varying,compression or small viewpoint changes.

A fast and robust fundamental matrix estimation method based on Sequential Similarity Detection Algorithm(SSDA) is presented to estimate the fundamental matrix rapidly and accurately.The SSDA is introduced into the Maximum a Posteriori Sample Consensus(MAPSAC) to search the optimum model parameters and the accumulation times of computing a cost function are cut down by eliminating the false model as soon as possible,which not only keeps the better robustness of MAPSAC,but also reduces its computation effectively.Then,the initial inliers obtained by the improved MAPSAC are optimized with a M-estimator.Those inliers with larger residual errors are removed and the optimized inliers are used to compute the fundamental matrix to enhance the precision and improve the robustness of the algorithm.Experiment results demonstrate that the proposed algorithm performs better in accuracy and robustness,and its average speed has increased at least 30% as compared with that of the MAPSAC.The proposed algorithm can satisfy the requirements for real-time,precision and robustness in the fields such as three-dimensional reconstruction,image matching,image tracking and camera self-calibration.

Heat pipe with groove--shaped capillary structure always shows smaller heat transfer limit. It is because that traditional fabrication technique leads to the difficulty in minimizing the geometric dimension of grooves. As a result, novel fabrication technique is of great importance. In this paper, we will discuss some heat transfer characteristics of heat pipe fabricated by novel Extrusion–ploughing process. Owing to the extrusion from tools in the fabrication course, two kinds of grooves, namely leading grooves and secondary grooves, are formed in this kind of heat pipe. This feature will polish the groove geometric structure. Furthermore, considering the fact of parallel combination of these two kinds of grooves, excellent heat transfer performance of novel heat pipe fabricated by novel Extrusion–ploughing process can be expected. The experiments of testing temperature changes versus time at evaporator sector and condenser sector at different work temperature are conducted. The temperature distribution along axial direction of this kind of novel heat pipe at its steady stage is also tested. The experimental results prove that the heat pipe fabricated by Extrusion–ploughing process exhibits ideal isothermal performance and excellent heat respond speed. When compared with normal axially grooved heat pipe, this novel kind of heat pipe also shows larger final heat transfer limit.

In a thermal simulation experiment of gold tubes of closed-system, calculating with the KINETICS and GOR-ISOTOPE KINETICS software, kinetic parameters of gas generation and methane carbon isotopic fractionation from Triassic—Jurassic hydrocarbon source rocks in the Kuqa depression of Tarim Basin are obtained. The activation energies of methane generated from Jurassic coal, Jurassic mudstone and Triassic mudstone in the Kuqa Depression are 197–268 kJ/mol, 180–260 kJ/mol and 214–289 kJ/mol, respectively, and their frequency factors are 5.265times1013s−1, 9.761times1011s−1 and 2.270times1014s−1. This reflects their differences of hydrocarbon generation behaviors. The kinetic parameters of methane carbon isotopic fractionation are also different in Jurassic coal, Jurassic mudstone and Triassic mudstone, whose average activation energies are 228 kJ/mol, 205 kJ/mol and 231 kJ/mol, respectively. Combined with the geological background, the origin of natural gas in the Yinan-2 gas pool is discussed, and an accumulation model of natural gas is thus established. The Yinan-2 gas is primarily derived from Jurassic coal-bearing source rocks in the Yangxia Sag. Main gas accumulation time is 5–0 Ma and the corresponding Ro is in the range from 1.25%–1.95%. The loss rate of natural gas is 25%–30%.

Constrained by the micro geometry structure, a heat pipe with groove shaped capillary structure fabricated by the traditional method always shows smaller heat transfer limits. To solve this, a novel fabrication technique is of great importance. In this paper, we will discuss about heat pipes fabricated by a novel extrusion–ploughing process. Because of the extrusion from tools, two kinds of grooves, namely a leading groove and a secondary groove, are formed in this kind of heat pipe. This feature will polish the geometry structure of an ordinary heat pipe. Considering the fact of the parallel combination of these two kinds of grooves, improvement on the heat transfer performance can be expected. By experiments, the empirical mathematical regression equations relating the fabrication parameter to the geometry groove dimensions and the theoretical calculation of heat transfer limits are established here. The results show the heat pipe fabricated by the extrusion–ploughing process exhibits larger heat transfer limits when the work temperature ranges from 340 to 390 K.

Study design A retrospective study had been conducted to evaluate the efficacy and safety of anterior cervical discectomy and fusion (ACDF) at C2-C3 for traumatic spondylolisthesis of the axis (TSA). Objective The present study had been done to evaluate the results and feasibility of the surgical treatment with ACDF at C2-C3, for the fixation of unstable TSA. Summary of background data The treatment for unstable TSA is still controversial. Anterior surgical managements of TSA used to be considered as a complex procedure with high rate of morbidity. Though some authors obtained satisfying results of ACDF for TSA, there was still no report of a relatively large series to evaluate the outcome. Methods Since February 2001-August 2005, ACDF at C2-C3 had been performed in 30 cases of unstable TSA (Type II: 14 cases, Type IIa: 12 cases, and Type III: 4 cases, based on Levine-Edwards' classification). Arthrodesis was done by autogenous iliac graft (13 cases) or cages (17 cases). An average follow-up of 12 months was achieved (range from 6 to 48 months). Combined morbidity, operative time, days of hospitalization, complications, neurologic improvement, and fusion rate was assessed. Results Average operative time and hospitalization were similar to those of ACDF for lower cervical spine (102 minutes, and 9 days). No patient received blood transfusion. Plate was generally used. Axial pain was relieved in each case. The patients with preoperative neurologic deficits all got improvements. The only complication was choking and trouble in swallowing liquids in 1 case, and it diminished 3 months after operation without any treatment. No graft or plating related complication was observed. Fusion was achieved in all cases within 6 months. Conclusion ACDF at C2-C3 may be a feasible and safe way to treat unstable TSA.

Capable of infecting hundreds of thousands of hosts, worms represent a major threat to the Internet. However, the defense against them is still an open problem. This paper attempts to answer an important question: How can we distinguish polymorphic worms from normal background traffic? We propose a new worm signature, called the position-aware distribution signature (PADS), which fills the gap between traditional signatures and anomaly-based intrusion detection systems. The new signature is a collection of position-aware byte frequency distributions. It is more flexible than the traditional signatures of fixed strings while it is more precise than the position-unaware statistical signatures. We propose two algorithms based on expectation-maximization (EM) and Gibbs sampling to efficiently compute PADS from a set of polymorphic worm samples. We also discuss how to separate a mixture of different polymorphic worms such that their respective PADS signatures can be calculated. We perform extensive experiments to demonstrate the effectiveness of PADS in separating new worm variants from normal background traffic.

Overhead transmission line icing is one of the main factors affecting safety and reliability of power grid, and the cascading failure may occur due to the iced transmission line. In this paper, a risk evaluation method is proposed to evaluate the cascading failure risk caused by the transmission line icing. Based on the ice accretion model of the transmission line, a piecewise linear model of the transmission line failure probability considering the icing thickness is established. And the Value at Risk (VaR) and Conditional Value at Risk (CVaR) are used to evaluate the security levels of the power system threatened by icing transmission line. Simulation of an IEEE 118 system is carried out to investigate the performance of the proposed risk evaluation method. The simulation results show that the proposed method could evaluate the grid risk caused by transmission line icing. And longer icing time will result in greater cascading failure risk. Also, the cascading failure risk is affected by the position of the iced transmission line.

Detailed procedures for the modelling of synthesis load of practical power network are presented; then based on the detailed investigation and statistics of load composition at 220 kV and 330 kV substations, the distribution of different kinds of load in domestic power grids are analyzed and the necessity of establishing the parameters of synthesis load model (SLM) suitable to actual power networks is pointed out; finally, the influence of SLM parameters on stability of interconnected power grids is researched. Research results show that it is crucially important for accurate analysis on power grid stability to choose appropriate load model and parameters.