Can multiscale traffic analysis be used to differentiate Internet applications?

An accurate mapping of Internet traffic to applications can be important for a broad range of network management and measurement tasks, including traffic engineering, service differentiation, performance/failure monitoring and security. Traditional mapping approaches have become increasingly inaccurate because many applications use non-default or ephemeral port numbers, use well-known port numbers associated with other applications, change application signatures or use traffic encryption. In this paper we will demonstrate that multiscale traffic analysis based on multi-order wavelet spectrum can be used as a discriminator of Internet applications traffic profiles. By performing clustering analysis over the multiscale wavelet spectrum coefficients that are inferred from the measured traffic, the proposed methodology is able to efficiently differentiate different IP applications without using any payload information. This characteristic will allow the differentiation of traffic flows in unencrypted and encrypted scenarios. In order to compare the differentiating potential of different traffic application data, upload, download and joint upload and download flow statistics are considered to evaluate the identification approach for each selected protocol. Moreover, we also evaluate which timescales and spectrum orders are more relevant for the traffic differentiation. From the analysis of the obtained results we can conclude that the proposed methodology is able to achieve good identification results using a small set of timescales of a single order wavelet spectrum of a general raw traffic statistic.     

Optically Powered Temperature Measuring Instrument for Big Rotor

Abstract: A micro - power consumption non - contact temperature measuring instrument for big rotor is introduced. As it solves very well the signal coupling under high speed rotation and power supply problem for probe, the instrument can realize persistent on - line temperature measurement for big rotor drived by the ordinary light transmitted by optical fiber under the room light.     

Optically Powered Temperature Measuring Instrument for Big Rotor^①

A micro-power consumption non-contact temperature measuring instrument for big rotos is introduced.As it solver very well the signal coupling under high speed rotation and power supply problem for probe,the instrument can realize persistent on-line temperature measurement for big rotor drived by the ordinary light transmitted by optical fiber under the room light.     

Development and Application of Big Data Platform for “Bohai granary”

Vehicular ad-hoc network (VANET) is an emerging paradigm for road transportation which minimizes traffic, accidents and improves fuel efficiency. VANET uses the position of the vehicle obtained from satellite system such as global positioning system (GPS), global navigation satellite system, Compass and Galileo as a location id in position-based routing protocol. The position obtained from the satellite system is likely to have an error due to environmental and technical issues which effect the routing performance. Thus, this paper proposes a position-based routing protocol which uses Kalman filter based location prediction technique to improve routing performance by minimizing location error. The routing protocol performance is evaluated on NS-3.23 simulator with real time GPS traces and simulator generated mobility on Two-ray ground and Winner-II propagation model for 500 m transmission range. Further, performance is compared with other prediction-based routing protocol on the metrics of packet delivery ratio, average delay and throughput.     

Dispersion penalty analysis for VSR-1 optical links

This paper presents an approach to calculate dispersion penalty for VSR-1 optical links. Based on parameters of a specific VSR-1 link, dispersion penalties are computed for various modal dispersion bandwidths respectively. The worst-case eye closure is expressed numerically by using the signal waveform at time 0, and the signal waveform is obtained in frequency domain through FFT algorithm. By this approach,the dispersion penalty is determined by the shape of transfer functions of the various components in the links. To simplify the derivation of multimode fiber link transfer function,a Gaussian form of normalized impulse response is used. This calculation approach can be used to estimate the worst-case dispersion penalty of VSR-1 links in the link budget analysis.     

µBIGMSA-Microservice-Based Model for Big Data Knowledge Discovery: Thinking Beyond the Monoliths

Wireless Personal Communications - Enterprise thrives on software applications that are built to fulfil the core business requirements. A single business application can offer a cluster of...     

Steady-state analysis of the carrier synchronizer for QPSK signals†

In this paper, the steady-state analysis of the carrier synchronizer consisting of the cascade of a bandpass filter (BPF), and non-linearity (NL) and a phase-locked loop (PLL) for a quadrature phase shift keyed (QPSK) signal corrupted by white gaussian noise is presented. The analysis is based on the transform method and the harmonic representation of cyclostationary processes. Some of the conclusions are similar to those obtained from the non-return to zero (NRZ) pulse amplitude modulated (PAM) synchronizer. Among these include: (1) the odd symmetry NL cannot be adopted to restore the carrier; (2) there is an optimum bandwidth of the BPF to minimize the phase jitter of the synchronizer output signal; and (3) conventional design theory still applies for the PLL in the QPSK carrier synchronizer. In addition to these results, we also conclude that: (1) we have to choose a harmonic with order of at least 4; and (2) the PLL output phase variance is more sensitive to the synchronizer input signal-to-noise ratio (S/N) than the NRZ synchronizer. A significant improvement of the QPSK synchronizer performance over that of the NRZ case is possible when the S/N is large.     

Thermo—analysis of Preparation Process for Electron Trapping Materials

The heated process of raw materials for electron trapping maerials(EMT) is investigated by thermo-analysis method.The temperature range of raw materials experienced some physical and chemical change processes,such as dehydration,organic solvent removal,crystal sulphur burning,oxidation of alkaline earth sulfides and solid phase reaction(rare earth doped)and so on,are obtained.The experimental results also show thaat the presence of oxygen in shielded gas is very harmful to prepare the ETM.The raw material thermo-analysis results provide very important experimental reference for optimizing the ETM preparation techniques.     

Probabilistic analysis of micro-machined fixed?fixed beam for reliability

A realistic approach for modelling a fixed?fixed beam is presented. The use of probabilistic methods to assess the electromechanical behaviour of the beam under the presence of micro-machine manufacturing and process uncertainties is demonstrated. A finite-element model of the beam is constructed using the commercial code ANSYS (10.0). In the standard approach of modelling, existing literature assumes deterministic values for design parameters, however, fabrication of the device introduces some amount of variation in the design parameters. Here, the probabilistic approach is discussed to account for the variability in fabrication. Probabilistic analysis guides the design of the fixed?fixed beam to achieve a robust and reliable design in the most efficient way. The results of the probabilistic design approach on the performance characteristics such as maximum deflection and maximum stress will be discussed.     

Noise analysis of a first-order thermal ΣΔ architecture for convective accelerometers

This paper presents the study of an original closed-loop conditioning approach for fully-integrated convective inertial sensors. The method is applied to an accelerometer manufactured on a standard CMOS technology using an auto-aligned bulk etching step. Using the thermal properties of the sensor, a first order sigma-delta modulator is built. This “electro-physical” modulator realizes an analog-to-digital conversion of the acceleration signal. Besides, the feedback mode of operation improves the sensor overall performance.     

A performance analysis of HICCUPS—a steganographic system for WLAN

The paper presents an analysis of performance features of the HICCUPS (HIdden Communication system for CorrUPted networkS) including the efficiency and the cost of the system in WLANs (Wireless Local Area Networks). The analysis relies on the original CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) 802.11 Markov chain-based model and proves that the HICCUPS is the efficient steganographic method with the reasonable cost.     

A novel hand exoskeleton to enhance fingers motion for tele-operation of a robot gripper with force feedback☆

This research describes a robotic system's design, optimization, and implementation processes for tele-operation with haptic feedback using the Hand Exoskeleton of New technologies research center (HEXON) as a novel haptic mechanism and the HEXON robotic gripper to work collaboratively with the exoskeleton. In particular, a force-sensitive robotic gripper is connected to a hand exoskeleton, mimics the user's hand movements, and transfers haptic feedback through the exoskeleton. The two-finger exoskeleton's design process consists of a multi-criteria optimization procedure to simultaneously maximize applied force to the finger and workspace of the attached exoskeleton, optimizing both the Perpendicular Impact Force (PIF) and the Global Isotropy Index (GII), considering worst-case collision avoidance. Due to the tele-operation application and using a robotic arm as a slave in the remote scenario, the gripper can be used as an end-effector for a palletizing 3-DOF robotic arm, and movement of the gripper can be achieved by using a visual sensor to pinpoint the user's hand location in 3D space. With the aim of the stress analysis software, the exoskeleton and gripper designs were analyzed to evaluate the system strength against applied forces. Finally, based on the achieved results, the gripper and two-fingered exoskeleton prototypes were fabricated. Simulations and experimental results are reported, showing the potential of the HEXON in haptics and tele-operation applications, and the exoskeleton is used to operate a robotic arm and gripper while the user can perceive the objects virtually.     

Does internet security matter for foreign direct investment? A spatial econometric analysis

This paper examines the impact of the Internet security environment on Chinese outward foreign direct investment (FDI) using a merged cross-country data set over 2010–2017 with a dynamic spatial model. The results show that Internet security is a crucial determinant for Chinese firms to make location decisions overseas. Particularly, a secure Internet significantly promotes Chinese outward FDI to a host country. In contrast, Internet security in surrounding countries yields negative spatial location spillovers that hinder Chinese firms from investing in the host country. This phenomenon can be regarded as a national competition for Internet security to attract FDI. Mechanism tests show that Internet security promotes FDI in host countries through four channels: operating cost reductions, transaction cost-cutting, information asymmetry decreases, and confidentiality protection. Further heterogeneous analyses show that the impact of Internet security is more significant as time passes and the host country becomes an Internet society. In contrast, specific international cooperation frameworks led by China weaken the location effect of Internet security for Chinese outward FDI. These results are robust after controlling for potential endogeneity and to different specifications. Therefore, the host authorities should endeavor to create a high-quality Internet security environment to attract FDI.     

Performance analysis of an ad hoc network for emergency and collaborative environments

Ad hoc networks can be used for quickly set up small spontaneous networks, such as in emergency situations or during sessions of cooperative works as in conferences, teaching rooms or meetings. Real-life tests of such networks are invaluable in order to assess models used in simulation. However, the number of factors affecting the performance of an ad hoc network is high, theoretically infinite. There are, for example, system factors, such as routing protocols, MAC and physical layer protocols and their cross-layer interaction, as well as environment factors, such as the presence of walls, foliage and surrounding moving objects. In order to optimize protocols, it is important both to design repeatable experiments of the network and to identify the parameters which really affect the system behavior. We accomplish the former demand by building a simple network by means of off-the-shelf hardware and software. For the latter point, we propose to use methods of statistical testing theory to identify these parameters in a compact manner. In particular, we use OLSR as a routing protocol. Results from real experiments in outdoor and indoor scenarios confirm the horizon effect of ad hoc multi-hop networks and show that there is a treatment effect caused by the window size of OLSR.     

Security analysis of pure DDP-based cipher proper for multimedia and ubiquitous device

DDP-64, based on various controlled operations, is a 64-bit Feistel-like block cipher consisting of 10 rounds with a 128-bit key. It was designed to attempt to have a high security level and a high speed performance in hardware on ubiquitous computing systems and multimedia. In this paper, however, we show that DDP-64 doesn’t have a high security level, more precisely, we show that it is vulnerable to related-key differential attack. This attack, which is much faster than the key exhaustive search, requires about 2⁵⁴ data and 2⁵⁴ time complexities. This work is the first known cryptanalytic result on DDP-64 so far.     

Performance analysis of the IEEE 802.16e sleep mode for correlated downlink traffic

In this paper, we evaluate the performance of the IEEE 802.16e sleep mode mechanism in wireless access networks. This mechanism reduces the energy consumption of a mobile station (MS) by allowing it to turn off its radio interface (sleep mode) when there is no traffic present at its serving base station (BS). After a sleep period expires, the MS briefly checks the BS for data packets and switches off for the duration of another sleep period if none are available. Specifically for IEEE 802.16e, each additional sleep period doubles in length, up to a certain maximum. Clearly, the sleep mode mechanism can extend the battery life of the MS considerably, but also increases the delay at the BS buffer. For the performance analysis, we use a discrete-time queueing model with general service times and multiple server vacations. The vacations represent the sleep periods and have a length depending on the number of preceding vacations. Unlike previous studies, we take the (short-range) traffic correlation into account by assuming a D-BMAP arrival process, i.e. the distribution of the number of packet arrivals per slot is modulated by the transitions in a Markov chain with N background states. As results, we obtain the distribution of the number of packets in the queue at various sets of time epochs, the distribution of the packet delay and the antenna activity rate. We apply these results to the IEEE 802.16e sleep mode mechanism with correlated downlink traffic. By means of some examples, we show the influence of both the configuration parameters and the traffic correlation on the delay and the energy consumption.     

What and how well you exercised? An efficient analysis framework for fitness actions

Human action analysis has been an active research area in computer vision, and has many useful applications such as human computer interaction. Most of the state-of-the-art approaches of human action analysis are data-driven and focus on general action recognition. In this paper, we aim to analyze fitness actions with skeleton sequences and propose an efficient and robust fitness action analysis framework. Firstly, fitness actions from 15 subjects are captured and built to a fitness action dataset (Fitness-28). Secondly, skeleton information is extracted and made alignment with a simplified human skeleton model. Thirdly, the aligned skeleton information is transformed to an uniform human center coordinate system with the proposed spatial–temporal skeleton encoding method. Finally, the action classifier and local–global geometrical registration strategy are constructed to analyze the fitness actions. Experimental results demonstrate that our method can effectively assess fitness action, and have a good performance on artificial intelligence fitness system.     

Do educational inequalities affect Internet use? An analysis for developed and developing countries

This study investigates whether the existence of educational inequalities at the country level affects Internet use. Additionally, we explore the extent to which these impacts depend on countries’ economic development levels. We use a logit model and data set of 69 high- and middle-income countries for the period 2005–2015. We find a negative relationship between Internet use and education inequality for the whole sample. The results confirm that, in addition to the level of education and other socioeconomic variables, the distribution of formal education among citizens within a country is also important to explain Internet use. We also obtain that this distribution affects Internet use to a higher extent in middle-income economies in comparison with high-income ones. Unlike the positive influence of educational levels obtained in the academic literature, the existence of within-country educational disparities negatively influences Internet use. This study demonstrates the influence of countries’ educational structure in relative terms in explaining Internet use.     

Design and analysis of a CMOS passive Σ∆ ADC for low power RF transceivers

Design and analysis of a Σ∆ modulator with a passive switched capacitor loop filter is presented. Design steps for optimum loop filter design for quantization noise suppression and thermal noise reduction is outlined. Design specifications for sampling clock phase noise, reference buffer and input buffer settling is analyzed. Presented design has a 2nd-order loop filter and uses only metal-metal capacitors and thin oxide digital transistors with no additional components occupying less than 0.1 mm² silicon area in 0.13 μm CMOS digital process. Measurement results show that the ADC achieves 80 dB peak SNR at a 100 kHz integration bandwidth with 1 pJ/sample conversion efficiency. With decimation filter power consumption of 0.22 mW at 104 MHz sampling rate, the ADC consumes only about 1 mA at 1.5 V for each channel.