An enhanced technique for online discrete cosine transform-based time-varying delay estimation

Time-delay estimation is developed in the transform domain where discrete cosine transform (DCT) coefficients of time-varying delay signals are estimated. The DCT is very efficient in compacting the signal energy in a small number of coefficients. Hence, the estimation of time-varying delay is obtained through the calculation of a small number of the DCT coefficients. An online maximum likelihood estimator of time-varying delay is developed. The coefficients of the transformed delay signal are obtained by maximizing the likelihood function. When dealing with noisy signals, it is observed that increasing the number of estimated DCT coefficients beyond a certain level does not produce better estimates of the delay signal. This happens because the extra DCT coefficients accommodate the noise present in the received signals.     

Zero-quantised discrete cosine transform prediction technique for video encoding

A new analytical model to eliminate redundant discrete cosine transform (DCT) and quantisation (Q) computations in block-based video encoders is proposed. The dynamic ranges of the quantised DCT coefficients are analysed, then a threshold scheme is derived to determine whether the DCT and Q computations can be skipped without video quality degradation. In addition, fast DCT/inverse DCT (IDCT) algorithms are presented to implement the proposed analytical model. The proposed analytical model is compared with other comparable analytical models reported in the literature. Both the theoretical analysis and experimental results demonstrate that the proposed analytical model can greatly reduce the computational complexity of video encoding without any performance degradation and outperforms other analytical models     

Adaptive fault-tolerant DVFS with dynamic online AVF prediction

Advances in silicon technology and shrinking the feature size to nanometer levels make random variations and low reliability of nano-devices the most important concern for fault-tolerant design. Design of reliable and fault-tolerant embedded processors is mostly based on developing techniques that compensate reliability shortcomings by adding hardware or software redundancy. The recently-proposed redundancy adding techniques are generally applied uniformly to all parts of a system and lead to heavy overheads and inefficiencies in terms of performance, power, and area. Efficient employment of non-uniform redundancy becomes possible when a quantitative analysis of a system behavior while encountering transient faults is provided. In this work, we present a quantitative analysis of the behavior of an embedded processor regarding transient faults and propose a new approach that accurately predicts the architecture vulnerability factor (AVF) in real-time. Another critical concern in design of new-silicon processors is power consumption issue. Dynamic voltage and frequency scaling (DVFS) is an effective method for controlling both energy consumption and performance of a system. Since rate of radiation-induced transient faults depends on operating frequency and supply voltage, DVFS techniques are recently shown to have compromising effects on electronic system reliability. Therefore, ignoring the effects of voltage scaling on fault rate could considerably degrade the system reliability. Here, by exploiting the proposed online AVF prediction methodology and based on analytic derivation, we propose a reliability-aware adaptive dynamic voltage and frequency scaling (DVFS) approach in case study of Multi-Processor System on Chip (MPSoC) with Multiple Clock Domain (MCD) pipeline architectures in which the frequency and voltage are scaled by simultaneously considering all three of power consumption, reliability, and performance. Comparing to the traditional methods of reliability-aware DVFS systems, the proposed reliability-aware DVFS method yields 50% better power saving at the same reliability level.     

ASON BoD业务在线预测与带宽调整研究

文章提出了微粒群优化的3层BP神经网络在线3步预测智能光网络带宽按需分配(BoD)业务流量模型,并改进了微粒群优化算法.对适应值较差的一部分微粒施加随机扰动,然后评估扰动效果,接受进化同时以一定概率接受退化.按3步预测中的最大值分配带宽,降低了突发业务阻塞率.仿真结果表明,该预测模型适应突发性、多样性BoD业务流量的在线预测.     

Operation data prediction algorithm of information system based on discrete second-order difference

Wireless Networks - This study proposes an algorithm for predicting the running data of information systems based on discrete second-order difference clustering. The wide stationary time series...     

基于优化KNN算法的线上拍卖价格预测模型

利用相似而已成交的其他拍卖可对正在进行的线上拍卖进行最终成交价格预测,但要使预测精度得到提高,需要相关属性特征对最终成交价格的影响程度信息。为此构建了一种遗传算法与K-最近邻(K-nearest neighbor)算法相结合的价格预测模型,采用遗传算法和交叉验证搜索出特征变量相对成交价格的最优权重,将最优权重加入相似度计算以决定最近邻并获得价格预测。通过利用ebay API获得真实线上拍卖数据进行实例研究,实验结果表明:该模型可以有效找出富含信息的特征变量,与传统算法比较明显提高了价格模型的预测精度。     

Interdisciplinary study on popularity prediction of social classified hot online events in China

We offer an interdisciplinary study of computer science and social science, analyzing behavior surrounding three types of online events: political events, social events, and non-public events. Based on the intrinsic characteristics of the three event types, this paper creates an effective method to predict such events. We continuously followed and recorded data every 10 min for 10 months from September 14, 2012 to July 11, 2013, and collected over 14 million “hot” posts from Sina Weibo, the largest microblogging provider in China. After removing spammers and noises, we developed a database of 4180 hot online events and 7,761,395 threads. We found that people’s online behavior regarding event types varies in terms of follow-up statistics and the predictability of events. The Chinese are, typically, quite concerned with social affairs that relate most closely to their personal interests and preferences. People tend to cluster around political events more often than social events and non-public events. This is demonstrated by an algorithm embedded with a clustering growth pattern of events, which predicts the popularity of online political events above others. The statistical findings are justified by Habermas’ public sphere theory and the theory of vertical/horizontal collectivism/individualism. This research provides an interesting piece of computational social science work to assist in the analysis of incentives concerning China’s collective events.     

Asymptotics and Error Rate Bounds for M-ary DPSK

The symbol error probabilityP_{E}(M)forM-ary DPSK is shown to be bounded in terms of a recent asymptotic approximationP_{asym}(M)by the inequalitiesP_{asym}(M) < P_{E}(M) < 1.03P_{asym}(M);M geq 4, E_{b}/N_{0} geq 1whereE_{b}/N_{0}is the bit energy-to-noise spectral density ratio. Aside from the wide range of validity and the closeness of the lower and upper bounds, this result is striking in light of the often held view that such asymptotic approximations are primarily of value only in the limitE_{b}/N_{0} rightarrow infty; thus, one of the goals of this note is to demonstrate that asymptotic methods can lead to extremely good error rate approximations in lieu of the more traditional and more widely used bounding techniques. The results are also noted to be applicable in other similar situations which commonly occur.     

Asymptotics of greedy algorithms for variable-to-fixed lengthcoding of Markov sources

In this paper, alphabet extension for Markov sources is studied such that each extension tree is grown by splitting the node with the maximum value for a weight as a generalization of the leaf probability in Tunstall's (1967) algorithm. We show that the optimal asymptotic rate of convergence of the per-symbol code length to the entropy does not depend on an a priori selected proportional allocation of the sizes of the extension trees at the states. We show this without imposing restrictive conditions on the weight by which the trees are extended. Further, we prove the asymptotic optimality of an algorithm that allocates an increasing total number of leaves among the states. Finally, we give exact formulas for all the relevant quantities of the trees grown     

Hidden double data transfer scheme for MDL design [merged DRAMlogic]

A high-speed DRAM data transfer scheme between DRAM and logic parts in merged DRAM logic (MDL) designs is proposed with logically divided DRAM row address mapping. The proposed scheme results in a 20% faster write access and 40% faster read access. It can be used as a general design framework to maximise DRAM access speed in various MDL designs. A test chip has been fabricated by 0.16 μm DRAM technology, and the scheme has been verified in the design of a DRAM L2 cache memory     

Evaluating reliability of question-disease relations in online health forms: A link prediction approach

The Internet has become an indispensable part of human life in today. People can now easily find answers to questions they are curious about via the internet. The short, effortless and free way that the Internet provides is extremely attractive for people to have an idea in subjects they wonder related to their health. There are many online health forums where people can ask questions answered by health professionals. Every day, people ask thousands of questions on these sites and get answers about which diseases their complaints may be related to. The frequent use of online forum sites by people has led to the selection of these forums as data source for this study, and analysis of reliability. Firstly, in this study, link prediction in bipartite social networks, where intensive works have been done and it is applied on many areas nowadays, is tried to be carried out on question-disease bipartite network constructed with data obtained from analysis of online health forums whose use rate increase substantially. For this purpose, a novel link prediction method called as intensive link prediction is proposed, and prediction success of this method is compared with five of similarity-based link prediction methods. Better results have been obtained with the proposed method than the other methods. Then, the accuracy of the answers given to the users on online health forums which received intense interest are tested. The reliability of online health forums is measured by the accuracy analysis performed.     

Distribution strategies for online retailers

The Internet provides retailers with potentially powerful opportunities to boost sales, increase market share, and generate new business through new services. One of the challenging questions that retailers are facing in that respect is how to organize the logistic fulfillment processes during and after the transaction has taken place. Based on a survey of 55 online retailers (both traditional and Internet-only) this paper investigates the distribution strategies of these different retailer types. This includes the use of infrastructure not particularly designed for delivery to Internet customers like stores and store warehouses, the logistics outsourcing strategy and the company's choice of delivery area. The independent variables studied are the delivery lead times offered to customers, the assortment choice, the number of Internet customer orders and the company type (traditional retailer or not). It is argued and demonstrated that the distribution channel for Internet customers should be integrated with existing operations, but for larger Internet order volumes, traditional retailers should switch to direct-delivery distribution centers. The outsourcing and delivery area decision appear to be mainly determined by the complexity of the assortment.     

Visual rhetoric for online documents

Many well-written online documents fail because their visual design does not account for the many differences between the paper page and display screen, nor do they take advantage of the display power of the computer. The author provides guidelines for practitioners based on extensive research on computer display. It is concluded that the visual design of the online document should be crafted to match its use, ensuring displays that are scanned quickly and read reliably     

Absolute-stability test for discrete systems

A numerical absolute-stability test for nonlinear discrete systems is proposed. The test is derived from the similar test for continuous systems given by ?iljak by the use of the bilinear transformation.