A Wireless Sensor Network (WSN) uses a larger number of low-power sensor nodes to gather environmental information which is then wirelessly forwarded to a base station. However, sensor nodes have ...very limited communication ranges. Thus, relay nodes are required to ensure reliable connectivity throughout the WSN. On the other hand, relay nodes are typically more sophisticated and expensive than sensor nodes. Therefore, deployment strategies should seek to minimize the number of required relay nodes, a problem referred to as the Steiner Tree Problem with Minimum Number of Steiner Points (SMT-MSP), which has been shown to be NP-hard. This paper analyzes and improves the 3-star approximation algorithm by reducing the time complexity from O(n 3 ) to O(nlogn) with the identical performance ratio. Experiments are conducted to verify the correctness of the proposed algorithm.
Newly developed techniques for intelligent sensor systems make it possible to register the mechanical wear-out of parts, such as band saws, ball screws and gearbox reducers, by collecting working ...signals from them, such as vibrations and preload pressure and temperature changes. To build an accurate wear model, we need to log as many real signals as possible from numerous parts in machine tools. This raises a substantial problem: How can we collect a large number of real signals from the parts installed in many machine tools - which could be located anywhere in the world - and aggregate data to use in constructing a wearing model, as well as enabling remote systems analysis and send warnings if the parts are worn? In this study, based on our previous work, we design a special embedded system to realize a cloud-based service that logs mechanical wear-out of parts. Both short and long range wireless communications are tested to evaluate its performance. The proposed system can be used to collect operating signals regarding mechanical wear-out of parts and can allow manufacturers to track state of wear and send warnings to tool owners before wear-out.
Cyclops Chan, Liwei; Hsieh, Chi-Hao; Chen, Yi-Ling ...
Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems,
04/2015
Conference Proceeding
This paper presents Cyclops, a single-piece wearable device that sees its user's whole body postures through an ego-centric view of the user that is obtained through a fisheye lens at the center of ...the user's body, allowing it to see only the user's limbs and interpret body postures effectively. Unlike currently available body gesture input systems that depend on external cameras or distributed motion sensors across the user's body, Cyclops is a single-piece wearable device that is worn as a pendant or a badge. The main idea proposed in this paper is the observation of limbs from a central location of the body. Owing to the ego-centric view, Cyclops turns posture recognition into a highly controllable computer vision problem. This paper demonstrates a proof-of-concept device, and an algorithm for recognizing static and moving bodily gestures based on motion history images (MHI) and a random decision forest (RDF). Four example applications of interactive bodily workout, a mobile racing game that involves hands and feet, a full-body virtual reality system, and interaction with a tangible toy are presented. The experiment on the bodily workout demonstrates that, from a database of 20 body workout gestures that were collected from 20 participants, Cyclops achieved a recognition rate of 79% using MHI and simple template matching, which increased to 92% with the more advanced machine learning approach of RDF.
Virtualization technology enables multiple virtual machines(VMs) to run on a physical mechanism. Due to the excessive data-intensive workloads of VMs, the system I/O performance of cloud platforms ...deteriorates. To improve the system I/O performance, one key technique is to exploit the spatial locality of data stored on the back-end disks. However, identifying data spatial locality on a cloud platform becomes challenging due to the transparency feature of virtualization. Therefore, to resolve the problem of poor disk I/O, this paper proposes an inter-VMs locality packing design to increase the number of sequential I/O accesses on back-end disks so as to improve disk I/O efficiency through exploiting the spatial locality of virtual machine images. Moreover, the proposed deign does not compromise the transparency of virtualization technique. A simulator architecture is also proposed to assess the performance of the proposed inter-VMs locality packing design.
Background
The aim of the present study was to investigate the use and value of maximum standardized uptake value (SUVmax) on positron emission tomography/computed tomography (PET/CT) images as a ...prognostic marker for patients with locally advanced pancreatic cancer (LAPC).
Materials and methods
The medical records of all consecutive patients who underwent PET/CT examination in our institution were retrospectively reviewed. Inclusion criteria were histologically or cytologically proven LAPC. Patients with distant metastasis were excluded. For statistical analysis, the SUVmax of primary pancreatic cancer was measured. Survival rates were calculated using the Kaplan–Meier method, and multivariable analysis was performed to determine the association of SUVmax with overall survival (OS) and progression-free survival (PFS) using a Cox proportional hazards model.
Results
Between July 2006 and June 2013, 69 patients were enrolled in the present study. OS and PFS were 14.9 months 95% confidence interval (CI) 13.1–16.7 and 8.3 months (95% CI 7.1–9.5), respectively. A high SUVmax (>5.5) was observed in 35 patients, who had significantly worse OS and PFS than the remaining patients with a low SUVmax (
P
= 0.025 and
P
= 0.003). Univariate analysis showed that SUVmax and tumor size were prognostic factors for OS, with a hazard ratio of 1.90 and 1.81, respectively. A high SUVmax was an independent prognostic factor, with a hazard ratio of 1.89 (95% CI 1.015–3.519,
P
= 0.045).
Conclusion
The present study suggests that increased SUVmax is a predictor of poor prognosis in patients with LAPC.
This paper presents an integrated color imaging system for taking images in extremely high dynamic range scenes. The system first fuses five differently exposed images in raw data such that the ...effective dynamic range of the fused raw data is extended to 256 times. Then it runs several edge detection iterations to extract the image details in different luminance levels and assigns larger dynamic range for highly populated regions.
Foreground detection is designed to separate the objects from a background scene. However, night scenes always contain high dynamic illumination variety so that the performance on detection drops ...largely. In this paper, we present a new foreground detection algorithm which is applicable to scenes with complicated illumination and shadow. This new algorithm utilizes multiple regions to perform background classification. Consequently human vision can focus on moving objects and the interferences such as night illumination or shadow can be effectively eliminated. Because this algorithm can eliminate most interference, therefore moving objects can be segmented more precisely. As our experiment, the precision of nigh scene foreground detection is highly improved compared with other techniques.
Fifty-six patients with de novo acute myeloid leukemia M4/M5 subtypes were studied for rearrangements of the mixed lineage leukemia gene, MLL (also called HRX, Htrx-1, or ALL-1). Ten patients (18%) ...showed rearrangements of the MLL gene, 9 in a major breakpoint cluster region within a centromeric 8.3-kb BamHI fragment, whereas rearrangement in one patient was the result of a direct tandem duplication of exons 2-6 of MLL. Analysis of sequences at the duplication junction revealed that the points of MLL fusion within introns 6 and 1 both lie within Alu elements. This suggests the involvement of Alu repeat mediated homologous recombination in MLL self fusion. For the 10 rearranged samples, cytogenetics analysis revealed a normal karyotype in 3, and 3 had abnormalities other than 11q23. Survival analysis of patients revealed no difference between those with rearrangement of MLL and those showing the germ-line configuration.
Nowadays many software services are hosted in the Cloud. When there are more requests on these services, there are also more queries sent to the underlying database. In order to keep up with the ...increasing workload, it is necessary to have multiple servers hosting the data. Some cloud providers offer the full data replication solution. However, this solution only works when the load mainly consists of the read requests, and when the number of write requests increases, it does not scale well. Although data decomposition has been widely used in data-intensive web sites, not much study has been done on how to decompose the underlying data of software services for the purpose of data replication. In this paper, we propose a data-decomposition-based partial replication model for software services. We devise an automatic algorithm for data decomposition under the constraint of the capacity limit of the host machines. We evaluate our approach from two aspects: scalability and performance, using two benchmarks: RUBiS and TPC-W. In the experiment, we test the algorithm using different workload inputs, and also compare our approach with the full data replication approach.
