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1.
Development of non-keyboard input device checklists through assessments   总被引:2,自引:0,他引:2  
An assessment of non-keyboard input devices (NKID) was conducted to identify factors for good design in relation to operation, performance and comfort. Twenty-seven NKID users, working in health and safety, evaluated eight devices that included mice, trackballs and a joystick mouse. The factors considered important for good design were: (1) comfortable hand and finger position, (2) adequate control, (3) intuitive and easy to use, (4) ease of device, button and trackball movement, (5) good interaction with software, (6) provision of suitable accessories. Mice were rated more favourably than trackballs or the joystick mouse. The design of the standard 2-button mouse (D4) was considered most desirable to use; the 3-button mouse (D1) and 3-button curved mouse (D8) were also favoured. Assessment data and comments were drawn together with previously published research to produce useful tools for NKID purchasing (i.e. Device Purchasing Checklist) and assessment (i.e. Device Assessment Checklist).  相似文献   

2.
Today, the world is taking large leaps of progress in technology. The technology is turning the vision of achieving transparency, speed, accuracy, authenticity, friendliness and security in various services and access control mechanisms, into reality. Consequently, new and newer ideas are coming forth by researchers throughout the world. Khan et al. (Chaos Solitons Fractals 35(3):519–524, 2008) proposed remote user authentication scheme with mobile device, using hash-function and fingerprint biometric. In 2012, Chen et al. pointed out forged login attack through loss of mobile device on Khan et al.’s scheme and subsequently proposed a scheme to improve on this drawback. Truong et al. (Proceedings of 26th IEEE International Conference on Advanced Information Networking and Applications, pp 678–685, 2012) demonstrated that in Chen et al.’s scheme, an adversary can successfully replay an intercepted login request. They also showed that how an adversary can make fool of both the participants of Chen et al.’s protocol by taking advantage of the fact that the user is not anonymous in scheme. Further, they proposed an improvement to Chen et al.’s scheme to cut off its problems. Through this paper, we show that Chen et al.’s scheme has some other drawbacks too and the improvement proposed by Truong et al. is still insecure and vulnerable. We also propose an improved scheme which overcomes the flaws and inherits the goodness of both the schemes, Chen et al.’s scheme and Truong et al.’s scheme.  相似文献   

3.
This paper presents a new interactive scatter plot visualization for multi-dimensional data analysis. We apply Rough Set Theory (RST) to reduce the visual complexity through dimensionality reduction. We use an innovative point-to-region mouse click concept to enable direct interactions with scatter points that are theoretically impossible. To show the decision trend we use a virtual Z dimension to display a set of linear flows showing approximation of the decision trend. We conducted case studies to demonstrate the effectiveness and usefulness of our new technique for analyzing the property of three popular data sets including wine quality, wages and cars. The paper also includes a pilot usability study to evaluate parallel coordinate visualization with scatter plot matrices visualization with RST results.  相似文献   

4.
In this paper, an automatic system is presented for target recognition using target echo signals of High Resolution Range (HRR) radars. This paper especially deals with combination of the feature extraction and classification from measured real target echo signal waveforms by using X-band pulse radar. The past studies in the field of radar target recognition have shown that the learning speed of feedforward neural networks is in general much slower than required and it has been a major disadvantage. There are two key reasons forth is status of feedforward neural networks: (1) the slow gradient-based learning algorithms are extensively used to train neural networks, and (2) all the parameters of the networks are tuned iteratively by using such learning algorithms (Feng et al., 2009, Huang and Siew, 2004, Huang and Chen, 2007, Huang and Chen, 2008, Huang et al., 2006, Huang et al., 2010, Huang et al., 2004, Huang et al., 2005, Huang et al., 2012, Huang et al., 2008, Huang and Siew, 2005, Huang et al., 2011, Huang et al., 2006, Huang et al., 2006a, Huang et al., 2006b, Lan et al., 2009, Li et al., 2005, Liang et al., 2006, Liang et al., 2006, Rong et al., 2009, Wang and Huang, 2005, Wang et al., 2011, Yeu et al., 2006, Zhang et al., 2007, Zhu et al., 2005). To resolve these disadvantages of feedforward neural networks for automatic target recognition area in this paper suggested a new learning algorithm called extreme learning machine (ELM) for single-hidden layer feedforward neural networks (SLFNs) (Feng et al., 2009, Huang and Siew, 2004, Huang and Chen, 2007, Huang and Chen, 2008, Huang et al., 2006, Huang et al., 2010, Huang et al., 2004, Huang et al., 2005, Huang et al., 2012, Huang et al., 2008, Huang and Siew, 2005, Huang et al., 2011, Huang et al., 2006, Huang et al., 2006a, Huang et al., 2006b, Lan et al., 2009, Li et al., 2005, Liang et al., 2006, Liang et al., 2006, Rong et al., 2009, Wang and Huang, 2005, Wang et al., 2011, Yeu et al., 2006, Zhang et al., 2007, Zhu et al., 2005) which randomly choose hidden nodes and analytically determines the output weights of SLFNs. In theory, this algorithm tends to provide good generalization performance at extremely fast learning speed. Moreover, the Discrete Wavelet Transform (DWT) and wavelet entropy is used for adaptive feature extraction in the time-frequency domain in feature extraction stage to strengthen the premium features of the ELM in this study. The correct recognition performance of this new system is compared with feedforward neural networks. The experimental results show that the new algorithm can produce good generalization performance in most cases and can learn thousands of times faster than conventional popular learning algorithms for feedforward neural networks.  相似文献   

5.
The focus of this paper is on the development and implementation of a genetic algorithm (GA)-based software system using message passing interface (MPI) protocol and library. A customized and improved form of simple GA used in previous research (Chen et al. 1997; Chen and Rajan 1998, 2000; Rajan et al. 1999) is parallelized. This MPI-enabled version is used to find the solution to finite element-based design optimization problems in a network of workstations. Results show that an almost linear speedup is obtained on homogenous hardware cluster and, with a proper load-balancing strategy, on heterogeneous hardware cluster.  相似文献   

6.
Understanding the dynamics of virtual communities has become an important issue for research. One concept that explains the participation in online communities is a sense of virtual community (SOVC), which is based on the offline equivalent sense of community (SOC) and describes a “spirit of belonging together”. Although these two concepts are similar, their measurement is problematic. Inspired by earlier studies, which investigated whether traditional SOC measures are appropriate for measuring SOVC, we adopted the SOC index 2 (SCI2) recently developed by Chavis et al. in a virtual setting. Our aim was to determine whether the refined SOC measurement is more suitable for virtual communities than their forerunners. We tested the SCI2 in a popular German community on 312 respondents. Our results showed that a thorough measure of SOVC still needs further refinement. We also discuss possibilities for improvement.  相似文献   

7.
Trackball-mice are devices that include both a trackball and a mouse. In this paper we discuss our experiences in building and testing trackball-mouse prototypes. We report four experiments on user performance with the prototypes used as trackball-mice, conventional mice, and in two-handed configuration with a separate trackball for the non-dominant hand. The results show that user performance with the two-handed configuration was better than in one-handed operation of a trackball-mouse and in one-handed operation of a mouse. Trackball-mouse use and conventional mouse use were more evenly matched. However, Trackball-mouse operation involves a skill that most users do not have whereas mouse operation is familiar to most. Therefore, widespread introduction of trackball-mice does not appear to be justified on performance grounds alone. However, trackball-mice can be used as regular mice by ignoring the ball. This makes them compatible with traditional graphical user interfaces while offering two extra degrees of freedom in tasks where they are beneficial.  相似文献   

8.
摘要2004年,Chen等人提出一个安全的匿名网络选举方案。指出Chen等人给出的方案是不安全的;另外,给出一个满足电子选举安全要求的修正方案。  相似文献   

9.
Chen (Computers and Electrical Engineering, vol. 30, 2004) illustrated that Tseng et al.’s authenticated encryption schemes, with message linkages for message flows, do not achieve their claimed integrity and authenticity properties. Furthermore, Chen presented some modified schemes to repair these flaws. In this paper, we show that the modified schemes proposed by Chen are not secure. In particular, we present an attack that allows a dishonest referee, in case of a dispute, to decrypt all the future and past authenticated ciphertext between the contended parties. We also present a simple fix to prevent this attack.  相似文献   

10.
An Improved Algorithm for Kernel Principal Component Analysis   总被引:5,自引:0,他引:5  
Kernel principal component analysis (KPCA), introduced by Schölkopf et al., is a nonlinear generalization of the popular principal component analysis (PCA) via the kernel trick. KPCA has shown to be a very powerful approach of extracting nonlinear features for classification and regression applications. However, the standard KPCA algorithm (Schölkopf et al., 1998, Neural Computation 10, 1299–1319) may suffer from computational problem for large scale data set. To overcome these drawbacks, we propose an efficient training algorithm in this paper, and show that this approach is of much more computational efficiency compared to the previous ones for KPCA.  相似文献   

11.
We study the complexity issues for Walrasian equilibrium in a special case of combinatorial auction, called single-minded auction, in which every participant is interested in only one subset of commodities. Chen et al. (J. Comput. Syst. Sci. 69(4): 675–687, 2004) showed that it is NP-hard to decide the existence of a Walrasian equilibrium for a single-minded auction and proposed a notion of approximate Walrasian equilibrium called relaxed Walrasian equilibrium. We show that every single-minded auction has a relaxed Walrasian equilibrium that satisfies at least two-thirds of the participants, proving a conjecture posed in Chen et al. (J. Comput. Syst. Sci. 69(4): 675–687, 2004). Motivated by practical considerations, we introduce another concept of approximate Walrasian equilibrium called weak Walrasian equilibrium. We show NP-completeness and hardness of approximation results for weak Walrasian equilibria. In search of positive results, we restrict our attention to the tollbooth problem (Guruswami et al. in Proceedings of the Symposium on Discrete Algorithms (SODA), pp. 1164–1173, 2005), where every participant is interested in a single path in some underlying graph. We give a polynomial time algorithm to determine the existence of a Walrasian equilibrium and compute one (if it exists), when the graph is a tree. However, the problem is still NP-hard for general graphs.  相似文献   

12.
In the original paper by Xu (ibid., vol.43, p.1027-30, 1998), a problem of learning motion trajectories with different time scales based on the learned control inputs was considered. It is suggested that the author was apparently unaware that such an idea was previously reported by Kawamura et al. (1987, 1995) based on the time-scale property of robot dynamics. In this note, we briefly review the literature and point out the difference between Xu's work and that of Kawamura et al. We show that the proof developed in the latter can also be applied to derive the time-scale learning controller for the class of nonlinear system considered in Xu. In reply, Xu acknowledges that he overlooked the work of Kawamura et al. He remarks that his original article was in the event published as 2 articles. He also mentions his work currently in progress  相似文献   

13.
Constructing virtual 3D historical scenes from literature and records is a very challenging problem due to the difficulty in incorporating different types of domain knowledge into the modeling system. The domain knowledge comes from different experts, including: architects, historians, rendering artists, user interface designers and computer engineers. In this paper we investigate the problem of automatically generating drawings of ancient scenes by ontologies extracted from these domains. We introduce a framework called onto-draw to generate semantic models of desired scenes by constructing hierarchical ontology concept domains. Inconsistencies among them are resolved via an iterative refinement algorithm. We implement the onto-draw based ontology design approach and inconsistency removal technique in the virtual Jing-Hang Grand Canal construction project (Chen et al., 2010) and achieve encouraging results.  相似文献   

14.
We study permutation betting markets, introduced by Chen et al. (Proceedings of the ACM Conference on Electronic Commerce, 2007). For these markets, we consider subset bettings in which each trader can bet on a subset of candidates ending up in a subset of positions. We consider the revenue maximization problem for the auctioneer in two main frameworks: the risk-free revenue maximization (studied in Chen et al., Proceedings of the ACM Conference on Electronic Commerce, 2007), and the probabilistic revenue maximization. We also explore the use of some certain knowledge or extra information about the possible outcomes of the market. We first show that finding the optimal revenue in the risk-free model for the subset betting problem is inapproximable. This resolves an open question posed by Chen et al. (Proceedings of the ACM Conference on Electronic Commerce, 2007). In order to identify solvable variants of the problem, we propose the singleton betting language which allows traders to bet an arbitrary value on one candidate for one position. For singleton bettings, we first provide a linear-time implementable necessary and sufficient condition for existence of a solution with positive revenue for any possible outcome. Furthermore, we develop an LP-based polynomial-time algorithm to find the optimum solution of this problem. In addition, we show how to extend this LP-based method to handle some extra information about the possible outcomes. Finally, we consider the revenue maximization problem in a probabilistic setting. For this variant, we observe that the problem of maximizing the expected revenue is polynomial-time solvable, but we show that maximizing the probability of achieving a pre-specified revenue is #P-Complete.  相似文献   

15.
In 2005, Chen et al. implemented a proxy raffle scheme for the Internet. Unfortunately, their scheme is unable to withstand Denial of Service (DoS) and impersonation attacks. We consequently propose a novel version of this scheme, in this paper, which can resist these malicious attacks. The security of our scheme is based on symmetric and asymmetric cryptosystems. A timestamp mechanism is also applied to prevent suffering the replay attack. Specifically, the communication load of our scheme is less than that of Chen et al.'s scheme. Thus, we can implement our method for the Internet as well as mobile devices.  相似文献   

16.
In many instances, numerical integration of space-scale PDEs is the most time consuming operation of image processing. This is because the scale step is limited by conditional stability of explicit schemes. We introduce the unconditionally stable semiimplicit linearized difference scheme that is fashioned after additive operator split (AOS) [Weickert, J. et al. (1998)], [Goldenberg, R et al., (2001)] for Beltrami and the subjective surface computation. The Beltrami flow [Kimmel, R. (1997) (1999)], [Sochen, N. et al. (1998)], is one of the most effective denoising algorithms in image processing. For gray-level images, we show that the flow equation can be arranged in an advection-diffusion form, revealing the edge-enhancing properties of this flow. This also suggests the application of AOS method for faster convergence. The subjective surface [Sarti, A. et al. (2002)] deals with constructing a perceptually meaningful interpretation from partial image data by mimicking the human visual system. However, initialization of the surface is critical for the final result and its main drawbacks are very slow convergence and the huge number of iterations required. We first show that the governing equation for the subjective surface flow can be rearranged in an AOS implementation, providing a near real-time solution to the shape completion problem in 2D and 3D. Then, we devise a new initialization paradigm where we first "condition" the viewpoint surface using the fast-marching algorithm. We compare the original method with our new algorithm on several examples of real 3D medical images, thus revealing the improvement achieved.  相似文献   

17.
In this paper, we analyze the protocols of Tan, Lim et al., Chen et al. and five protocols of Hölbl et al. After the analysis, we found that Tan et al.?s, Lim et al.?s and two protocols of Hölbl et al. are insecure against the impersonation attack and the man-in-the-middle attack, Chen et al.?s protocol cannot withstand the key-compromise impersonation attack, one protocol of Hölbl et al. is vulnerable to the insider attack, one allows an adversary to compute the private key of any user and one protocol allows her to compute the shared secret key.  相似文献   

18.
In this paper we present a secure and efficient transaction protocol that provides the anonymity and can detect the double spending. The proposed payment system is based on the ElGamal encryption scheme, the ElGamal signature scheme and the ElGamal blind signature protocol. We show that our transaction protocol is secure and efficient. We give the definitions of unlinkability and unforgeability of our security model and we prove that the proposed transaction protocol is unforgeable and satisfies the unlinkability property. We show that the proposed system is more efficient, in terms of the computation and communication cost, than the compared payment systems (Eslami et al. in Electron Commer Res Appl 10:59–66, 2011; Chen et al. in Electron Commer Res Appl 10:279–287, 2011; Liu et al. in Proceedings of second European PKI workshop: research and applications. Lecture notes in computer science, vol 3545, pp 206–214, 2005 and Chen et al. in Electron Commer Res Appl 10:673–682, 2011) for a customer who withdraws and spends an e-coin and for the merchant who verifies an electronic coin. Also, the proposed e-cash system is useful for the electronic transactions when the connection between the bank and the merchant is not available during the payment protocol. This means a less bandwidth of the payment protocol and then increases the speed of the electronic transaction.  相似文献   

19.
文毅玲  马建峰  王超 《计算机科学》2011,38(6):54-57,80
聚合签名由Boneh等人提出,主要是通过聚合多个签名为一个签名,来提高签名与验证的效率。提出一个新的基于身份的聚合签名方案。与Xu等人的同类方案相比,新方案在签名和验证时各少一次对运算,显著提高了计算效率。在Computational Diffie -Hellman (CDH)问题困难性假设下,提出的聚合签名在随机预言机模型下能抵抗存在性伪造攻击。此外,针对最近由Chcn等人提出的聚合签名方案给出一种攻击方法,指出其不能抵杭存在性伪造攻击。  相似文献   

20.
Uncertainty validation using frequency response data has been studied by several authors. If the uncertainty is assumed to be stable, then the problem amounts to one of boundary interpolation. It is shown in this paper that for more general uncertainty models, an additional constraint is needed in order for the results of Boulet et al. (1998) and Chen (1997) to be applicable. Boundary interpolation, together with the proposed constraint, gives a satisfactory answer to the validation problem for uncertainty models  相似文献   

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