Earticle

File systems treats Flash storage device as a traditional storage media with their logical address. However inside the Flash storage device, Flash Translation Layer (FTL) remaps logical address to physical address to hide physical limitation of Flash memory cells. Due to the address translation, intentional logical separation of file system’s layout does not directly applied to physical separation. As a result, the separate-intended file systems’ requests are mixed in physical location, which degrades write throughput, as well as Flash’s lifecycle. In this paper, we propose virtually separable Block management scheme for Flash storage system by introducing new common command interface and separable Block management in FTL. The experimental results show that the proposed scheme increases IO performance, as well as reduces flash-internal overhead.

Phase Shifting Profilometry is a method of structured light whose three-dimensional reconstructions are susceptible to error from Gamma distortion. In practice, the luminance nonlinearity caused by the Gamma distortion effect of a digital video projector and a digital camera yields undesired fringe intensity changes, which substantially reduce the measurement accuracy, and while the effects of the Gamma distortion diminish with an increasing number of employed phase-shifting patterns. A Gamma calibration method expressed as Fourier series and binomial series theorem is proposed to reduce the measurement error caused by the Gamma distortion. After Gamma calibration, the Gamma distortion effect is attenuated and the accuracy is enhanced. The linear least square is compensated the phase error of absolute phase still existing after Gamma calibration. To verify the presented method in this paper, a profilometry experimental system is constructed using digital video projector and CCD camera. The experiment results shown that, the Gamma calibration reduce the maximum phase error of absolute phase by 75.0%. After the linear least square compensation, the maximum phase error is only 5.9% of without any Gamma calibration or phase compensation. The reconstruction surface of a complex curve surface is hardly any waviness, which is clearly noted in the reconstruction of the same tested object without any correction or compensation.

Haptics-enabled virtual reality technologies allow users to sense force feedback and tactile feedback while manipulating 3D objects. This paper proposes a haptic gaming system which can contribute to improve the ability for discerning tactile textures and 3D shapes by using force and tactile feedbacks of the users’ fingers. Our haptic gaming system consists of three games: “Haptic Puzzle” for tactile texture cognition, “Shape Puzzle” for 3D geometric object cognition, and “Position Puzzle” for 3D space cognition. Through a number of experiments, we have confirmed the effectiveness of our system on enhancing the tactile textures and 3D shapes recognition. The discrimination test of four haptic properties (stiffness, damping, static friction, and dynamic friction) led us to confirm that the users were least sensitive with damping property, and the damping changes were also highly confused with stiffness changes. We also found that the stiffness and damping properties are more influential than friction properties for discriminating the objects via the tactile texture recognition test. The final experiment demonstrated that the visuo-haptic integrated recognition was more advantageous than single haptic recognition. Moreover, this work showed the feasibility that the proposed system can be used for evaluating one’s haptic visual discrimination capability.

In most large-scale distributed applications, publish/subscribe (P/S) systems allow a decoupling between senders and receivers to interact with publishers and subscribers. Recently, in these areas, there has been increasing emphasis in managing end-to-end message delivery performance and message order-based consistency, which have been addressed in distributed collaborative applications. Especially, a causally ordered delivery consistency is more useful for these applications in which a large number of processes request collaboratively and interactively. In P/S systems of wireless sensor networks (WSNs), data fusion, the process of correlating individual sensor readings into high-level sensing results, depends on a causally ordered delivery. And gossip protocols based on P/S systems are becoming one of the promising solutions for addressing P/S scalability problems and very useful for the applications with a mixture of diverse message order consistencies. In this paper, we present two versions of causally ordered delivery protocols based on P/S systems using gossip protocols. The one is that only the predecessors immediately before the multicast message are disseminated from brokers to subscribers. And the other, specifically for P/S systems of WSNs, is that the timestamps that represent the gossip round in which the immediate predecessors are generated are disseminated from brokers to subscribers. The features of these two versions might be highly scalable and suitable for the area of the applications requiring only the minimum causal information with flexible consistency.

The tremendous growth of data in recent years poses some key challenges for recommender systems. Theses keys are related with producing high quality recommendations and fast performing the composition recommended items. In this paper, we propose social clustering-based similar user index to not only improve the prediction of recommendations, but also compose personalized recommendations in fast. Through the experimental result, we show that proposed clustering method is more accurate than k-means which is prevalent clustering techniques. And, we reduce computation time needed for composing recommendation. That is, proposed clustering-based indexing method improves the performance of recommender systems which deals with a very large data.

Carbon emission trade is one of the most common carbon emission regulation policies, manufactures must take measures to cope with this new situation. This paper dedicated to design a decision support system (DSS) based on our proposed model. We examined the manufacture’s joint emission reduction effort and pricing decisions with carbon emission trade. We formulate this problem as a stackelberg game, the manufacture is leader, the retailer is follower, the optimal emission reduction effort and pricing decisions are derived. The impact of carbon emission trade on these decisions and profits is also investigated. A numerical example is also provided to verify our model and findings. We found that manufactures will invest to reduce emission and increase their wholesale price compared with the situation without carbon emission trade. A decision support system (DSS) integrating the proposed model and the analysis is developed as an efficient decision tool to help manufactures and retailers to optimize their decision. The visualized outputs of DSS allow the decision makers to gain better understanding the impact of carbon emission trade on decisions, facilitating their decision making process in carbon economics era.

Flash codes are used to handle decoding and encoding of digital information to flash memory devices. The performance of a flash code is usually evaluated using the write deficiency metric. This paper introduces the K-Partition Flash Code (KPFC) with BIFC-based sharing and explores some of its variants KPFC is a coding scheme that involves a sharing mechanism within partitions of a flash memory block. The technique was designed to allow more cell writes to flash devices in order to improve its performance by lowering its write deficiency. Computer simulations were conducted to estimate the average case performances of the flash codes. Simulation results showed that its performance is generally better than the flash codes in literature.

IPTV, acronym of Internet Protocol Television, is a system that delivers television services through Internet protocol networks. Therefore, an IPTV system consists of many subsystems including content management, user management, and broadcast management systems. Among the main subsystems, the distribution management system handles purchasing orders from distributors, transcoding original content into the format designated by the distributor, and transmitting transcoded content to the server designated by the distributor. In order to realize one source multi-use and to boost content circulation, an IPTV system should be open in that any authorized content providers are allowed to upload their content for circulation and any authorized distributors are allowed to circulate content. The distribution management subsystem of an IPTV system allows distributors to request for content circulation and system managers to process distributors’ requests. Therefore, a distribution management system is one of the most important subsystems of an IPTV system. This paper introduces our design of a distribution management system for IPTV systems.