Shuxue Ding, Andrzej Cichocki, Jie Huang and Daming Wei
We present an approach for blind separation of acoustic sources produced from multiple speakers mixed in realistic room environments. We first transform recorded signals into the…
Abstract
We present an approach for blind separation of acoustic sources produced from multiple speakers mixed in realistic room environments. We first transform recorded signals into the time‐frequency domain to make mixing become instantaneous. We then separate the sources in each frequency bin based on an independent component analysis (ICA) algorithm. For the present paper, we choose the complex version of fixedpoint iteration (CFPI), i.e. the complex version of FastICA, as the algorithm. From the separated signals in the time‐frequency domain, we reconstruct output‐separated signals in the time domain. To solve the so‐called permutation problem due to the indeterminacy of permutation in the standard ICA, we propose a method that applies a special property of the CFPI cost function. Generally, the cost function has several optimal points that correspond to the different permutations of the outputs. These optimal points are isolated by some non‐optimal regions of the cost function. In different but neighboring bins, optimal points with the same permutation are at almost the same position in the space of separation parameters. Based on this property, if an initial separation matrix for a learning process in a frequency bin is chosen equal to the final separation matrix of the learning process in the neighboring frequency bin, the learning process automatically leads us to separated signals with the same permutation as that of the neighbor frequency bin. In each bin, but except the starting one, by chosen the initial separation matrix in such a way, the permutation problem in the time domain reconstruction can be avoided. We present the results of some simulations and experiments on both artificially synthesized speech data and real‐world speech data, which show the effectiveness of our approach.
Details
Keywords
Wenxi Chen, Daming Wei, Shuxue Ding, Michael Cohen, Hui Wang, Shigeru Tokinoya and Naotoshi Takeda
To meet the increasing needs for ubiquitous healthcare, a mobile phone‐based system for monitoring multiple vital signs is under development. In this paper, design and…
Abstract
To meet the increasing needs for ubiquitous healthcare, a mobile phone‐based system for monitoring multiple vital signs is under development. In this paper, design and implementation of the system architecture are described. The hierarchy of this system comprises three layers, which respectively handle multiple vital signs sensing, data/command communication via either wireless or wired means, and healthcare management. The fundamental basis of the sensing layer is a wearable cordless sensor device for monitoring vital signs without discomfort to the user during daily activities. The data communication layer performs bi‐directional information exchange between the sensing layer and the management layer. The uppermost management layer conducts data mining and analysis for risk factors assessment and healthcare. Overall considerations of implementation method and prototype fabrication are outlined. Finally, applicability to a variety of real‐world situations, and provision of customizable solutions not only for home healthcare but also for other vital signs‐related domains (such as emergency rescue and safety guarantee) are discussed. Three of the most promising applications based upon this system are described.
Details
Keywords
Tay Teng Tiow, Chu Yingyi and Sun Yang
To utilize the idle computational resources in a network to collectively solve middle to large problems, this paper aims to propose an integrated distributed computing platform…
Abstract
Purpose
To utilize the idle computational resources in a network to collectively solve middle to large problems, this paper aims to propose an integrated distributed computing platform, Java distributed code generating and computing (JDGC).
Design/methodology/approach
The proposed JDGC is fully decentralized in that every participating host is identical in function. It allows standard, single machine‐oriented Java programs to be transparently executed in a distributed system. The code generator reduces the communication overhead between runtime objects based on a detailed analysis of the communication affinities between them.
Findings
The experimental results show that JDGC can efficiently reduce the execution time of applications by utilizing the networked computational resources.
Originality/value
JDGC releases the developers from any special programming considerations for distributed environment, and solves the portability problem of using system‐specific programming methods.
Details
Keywords
Shengfei Shi, Jianzhong Li, Chaokun Wang and Yuhui Wu
The purpose of this paper is to propose a novel resource management strategy, which needs no special frameworks and directory servers.
Abstract
Purpose
The purpose of this paper is to propose a novel resource management strategy, which needs no special frameworks and directory servers.
Design/methodology/approach
The key idea is to piggyback a little extra packet header on the normal routing message by resource providers randomly. The clients can obtain the resource information gradually and need no dedicated resource queries.
Findings
The results of simulation confirm the good performance of our algorithms in different situations in terms of query latency and power consumption.
Originality/value
A novel resource management strategy, which needs no special frameworks and directory servers. The approach can be used in many current routing protocols. The quality of service issue is also considered for resource discovery algorithm and broadcasting method.
Details
Keywords
Xingdong Shi, Weili Han, Yinsheng Li and Ying Huang
An enterprise application can be quickly built up by service composition. Business process composition is the essence of service composition. To build up such service‐oriented…
Abstract
Purpose
An enterprise application can be quickly built up by service composition. Business process composition is the essence of service composition. To build up such service‐oriented enterprise application, the developer needs an integrated design tool. The purpose of this paper is to present and integrated business‐process driven design for service‐oriented enterprise applications.
Design/methodology/approach
In the approach, there are three phases: business environment modeling, business process modeling, and script compiling. Business environment modeling adopts a new modeling technique which combines both the advantages of use case diagram and sequence diagram in UML. Business process modeling builds a concrete model according to business environment modeling. The mapping algorithms from business environment model to business process model are also given. At script compiling phase, the business process model is compiled into several deployable files. And then the paper presents a demonstration which shows how to apply our approach to developing a supply chain management system for the retail industry.
Findings
The analysis shows that the approach can meet the requirement of service‐composition. The approach can help business expert freely express their business requirement at business environment modeling phase; and help IT expert quickly design service‐oriented enterprise application according to business environment model at business process modeling phase.
Originality/value
This paper proposes a novel integrated approach to model and implement business‐process driven service composition, and presents an integrated tool based Eclipse to implement this approach.
Details
Keywords
Tianbo Lu, Binxing Fang, Yuzhong Sun and Xueqi Cheng
As a peer‐to‐peer scalable anonymous communication system, WonGoo is a tradeoff between anonymity and efficiency. Usually, the longer the path, the stronger the anonymity, but at…
Abstract
Purpose
As a peer‐to‐peer scalable anonymous communication system, WonGoo is a tradeoff between anonymity and efficiency. Usually, the longer the path, the stronger the anonymity, but at the same time the heavier the overhead. WonGoo lengthens the anonymity path and reduces the overhead, providing strong anonymity and high efficiency with layered encryption and random forwarding. The purpose of this paper is to analyze its performance in detail.
Design/methodology/approach
The paper focuses on measure the performance of WonGoo system with probability theory. First, it gives a brief description of the system and evaluate its payload. Then it presents a detailed security analysis of the system.
Findings
It is shown that WonGoo can protect against (n − 1) attack and provide variable anonymity, as well as how confident the collaborators can be that their immediate predecessor is in fact the path initiator. The paper measures the anonymity degree provided by WonGoo system based on information entropy and compare it with other anonymity systems.
Practical implications
The paper is helpful for the further development of WonGoo system. In addition, the results presented in this paper will be useful for users to design other anonymity system.
Originality/value
WonGoo is a peer‐to‐peer anonymity system that provides strong anonymity and high efficiency with layered encryption and random forwarding. The paper presents a detailed analysis of its performance with probability theory and measures its anonymity degree with information theory.
Details
Keywords
In recent years, principal component analysis (PCA) has attracted great attention in dimension reduction. However, since a very large transformation matrix must be used for…
Abstract
Purpose
In recent years, principal component analysis (PCA) has attracted great attention in dimension reduction. However, since a very large transformation matrix must be used for reconstructing the original data, PCA has not been successfully applied to image compression. To solve this problem, this paper aims to propose a new technique called k‐PCA.
Design/methodology/approach
Actually, k‐PCA is a combination of vector quantization (VQ) and PCA. The basic idea is to divide the problem space into k clusters using VQ, and then find a PCA encoder for each cluster. The point is that if the k‐PCA encoder is obtained using data containing enough information, it can be used as a semi‐universal encoder to compress all images in a given domain.
Findings
Although a k‐PCA encoder is more complex than a single PCA encoder, the compression ratio can be much higher because the transformation matrices can be excluded from the encoded data. The performance of the k‐PCA encoder can be improved further through learning. For this purpose, this paper‐proposes an extended LBG algorithm.
Originality/value
The effectiveness of the k‐PCA is demonstrated through experiments with several well‐known test images.
Details
Keywords
Jingshan Huang, Jiangbo Dang, Michael N. Huhns and Yongzhen Shao
The purpose of this paper is to present ontology alignment as a basis for mobile service integration and invocation.
Abstract
Purpose
The purpose of this paper is to present ontology alignment as a basis for mobile service integration and invocation.
Design/methodology/approach
This paper presents an automated schema‐based approach to align the ontologies from interacting devices as a basis for mobile service invocation. When the ontologies are ambiguous about the services provided, compatibility vectors are introduced as a means of maintaining ontology quality and deciding which service to choose to reduce the ambiguity.
Findings
Both precision and recall measurements are applied in the evaluation of the alignment approach, with promising results. In addition, for the compatibility vector system, it is not only proved theoretically that the approach is both precise and efficient, but it also shows promising results experimentally.
Originality/value
In cases where sufficient resources are not available and only a certain number of mobile devices can be chosen for interaction, this approach increases the efficiency by choosing suitable mobile device(s).
Research limitations/implications
This current approach makes use of a center ontology, but introduces the problem of how to handle the vulnerability issue inherent in this centralized solution. To analyze and solve this problem is a potential research direction.
Details
Keywords
The assumption that the family migrates as a unit downplays migrants’ circularity. This chapter focuses on China's rural–urban labor migrants that travel back and forth between…
Abstract
The assumption that the family migrates as a unit downplays migrants’ circularity. This chapter focuses on China's rural–urban labor migrants that travel back and forth between the sites of work and home community and between places of work. I argue that migrants and their households pursue work flexibility in order to obtain the best of the urban and rural worlds, by gaining earnings from urban work and at the same time maintaining social and economic security in the countryside. Work flexibility demands flexibility in household organization, in the form of division of labor and collaboration between genders, generations, and households. Based on a study in Sichuan, I examine household biographies and narratives to identify migrants’ work and household strategies.
Migrants change jobs frequently, switch from one type of work to another and one location to another readily, and often return to the home village for months or even years before pursuing migrant work again. Not only are migrants ready to split the household between the city and the countryside, but also they frequently change from one form of division of labor to another. The inside–outside model, where the wife stays in the village and the husband does migrant work, used to be the dominant arrangement. Over time, the outside–outside model, where both the husband and wife migrate to work and leave behind other family members, is increasingly popular. This is facilitated by intergenerational and interhousehold division of labor in the form of assistance by the extended family. Intergenerational division of labor takes place when the second generation is replacing the parents in migrant work. This research's findings support the notion that rural–urban migrants are fast becoming a hybrid segment of Chinese society, playing dual roles of farmers and urban workers and straddling the peasant and urban worlds.