15968688
Enhanced sensitivity refractive index sensor using tilted fiber Bragg grating with thinned cladding
Short-period fiber Bragg gratings with gratings planes tilted at an angle 8° corresponding to the fiber axis show core mode and a large number of cladding-mode resonances in transmission. The differences between the cladding-mode resonance and the core-mode resonance are used to detect the variation of the surrounding refractive index; this refractive index sensor is immune to temperature effects by experimental demonstrations. After the cladding of the tilted fiber Bragg grating was etched by the hydrofluoric, TFBGs with different diameters and different-order cladding modes were investigated; the sensitivity of a TFBG to the external index can be significantly improved by reducing the cladding radius. Enhanced sensitivity and accuracy are achieved when the surrounding refractive index changes between 1.333 and 1.4532.
14011281
Temperature wireless sensors network based on fiber Bragg grating
In this paper, we demonstrated a FBG (Fiber Bragg Grating) temperature sensor only using an EDFA and a single FBG in the wireless sensors network. By means of detecting the intensity of the light reflected from the sensing FBG, we can obtain the surrounding temperature perturbation. Using EDFA and photoelectric cell in stead of BBS (broad band source) and OSA (optical spectrum analyzer) respectively, which significantly decreases the cost of the sensing system. Finally, the sensing information can be collected, processed, and transmitted to the control center via the wireless network. This kind of FBG temperature wireless sensor network combined both the advantages of fiber grating sensor and wireless communication, which provides potential commercial application in some special fields, where the conditional sensors will not be feasible.
5724860
Mining Opinion Features in Customer Reviews
It is a common practice that merchants selling products on the Web ask their customers to review the products and associated services. As e-commerce is becoming more and more popular, the number of customer reviews that a product receives grows rapidly. For a popular product, the number of reviews can be in hundreds. This makes it difficult for a potential customer to read them in order to make a decision on whether to buy the product. In this project, we aim to summarize all the customer reviews of a product. This summarization task is different from traditional text summarization because we are only interested in the specific features of the product that customers have opinions on and also whether the opinions are positive or negative. We do not summarize the reviews by selecting or rewriting a subset of the original sentences from the reviews to capture their main points as in the classic text summarization. In this paper, we only focus on mining opinion/product features that the reviewers have commented on. A number of techniques are presented to mine such features. Our experimental results show that these techniques are highly effective.
32625268
An Energy-Minimizing Mesh Parameterization
In this paper, we propose a new energy-minimizing mesh parameterization method, which linearly combines two new energies EQ and EM. It not only avoids triangles overlap in the parameter domain, but also is invariant under rotation, translation and scale transformations. We first parameterize the original 3D mesh to the parameter plane by using the energy-minimizing parameterization, and get the optimal effect by optimizing the weights wij gradually. Experimental results indicate that this optimized energy-minimizing method has low distortion and good stability.
2750727
Stability Analysis of Social Foraging Swarm with Interaction Time Delays
This paper considers a swarm model with an attraction-repulsion function involving variable communication time lags and an attractant/repellent. It is proved that for quadratic attractant/repellent profiles the members of the swarm with time delays will aggregate and form a cohesive cluster of finite size in a finite time. Moreover, all the swarm members will converge to more favorable areas of the quadratic attractant/repellent profiles under certain conditions in the presence of communication delays.
1116530
Dynamic Incremental Data Summarization for Hierarchical Clustering
In many real world applications, with the databases frequent insertions and deletions, the ability of a data mining technique to detect and react quickly to dynamic changes in the data distribution and clustering over time is highly desired. Data summarizations (e.g., data bubbles) have been proposed to compress large databases into representative points suitable for subsequent hierarchical cluster analysis. In this paper, we thoroughly investigate the quality measure (data summarization index) of incremental data bubbles. When updating databases, we show which factors could affect the mean and standard deviation of data summarization index or not. Based on these statements, a fully dynamic scheme to maintain data bubbles incrementally is proposed. An extensive experimental evaluation confirms our statements and shows that the fully dynamic incremental data bubbles are effective in preserving the quality of the data summarization for hierarchical clustering.
1710451
Joint estimation of image and coil sensitivities in parallel MRI
Parallel magnetic resonance imaging (MRI) using multichannel receiver coils has emerged as an effective tool to reduce imaging time in various dynamic imaging applications. However, there are still a number of image reconstruction issues that have not been fully addressed, thereby limiting the level of speed enhancement achievable with the technology. This paper considers the inaccuracy of coil sensitivities in conventional reconstruction methods such as SENSE, and reformulates the image reconstruction problem as a joint estimation of the coil sensitivities and the desired image, which is solved by an iterative algorithm. Experimental results demonstrate the effectiveness of the proposed method especially when large acceleration factors are used