2016, 5(1):1-16. DOI: 10.12146/j.issn.2095-3135.201601001
Abstract:The emergence of cloud computing brought datacenter to new application environments and new requirements. Server virtualization, as the main enabling technology for cloud services, needed datacenter to increase the number, performance and variety of I/O devices to support more virtual machines, for which the traditional server I/O architecture could result in waste of resources, increasing of server density and rise of wiring complexity. I/O resource pooling was a promising architecture to solve these problems, by separating devices and servers and enabling elastic on-demand provisioning of I/O resources to servers. We designed and implemented a single root I/O virtualization based multi-root I/O resource pooling architecture. By using a hardware-based peripheral component interface express identifier re-mapping, different physical servers can share the same physical devices, and through a hot-plug based allocation method, virtual I/O device could be dynamically reallocated between servers. The correctness and performance of our pooling architecture was proved by a Field-Programmable Gate Array prototype in this paper.
2016, 5(1):17-23. DOI: 10.12146/j.issn.2095-3135.201601002
Abstract:The number of amputees is huge in China. Wearing a bionic prosthesis is one of important approaches to improve the activity ability of daily life for patients. The commercial prostheses are either too expensive or only with single degree of freedom which works awkward. In this paper, a shape adaptive prosthetic hand was proposed to meet the growing need for a low-cost, multifunction and humanoid appearance of a prosthetic hand. It can achieve three most common hand movements in activities of daily life, such as power grasp, precision grasp and lateral grasp, with only one driven motor. With the shape adaptive finger, the suggest that it can accomplish the desired movements.
2016, 5(1):24-32. DOI: 10.12146/j.issn.2095-3135.201601003
Abstract:In recent years, lithium iron phosphate (LiFePO4) power battery is widely used for electric vehicle. However, it is difficult to estimate the state of charge(SOC) of battery because of the characteristics of material itself. In complicated operation environments, SOC estimation plays a significant role in ensuring safety and reliability of battery operations for an electric vehicle. In this paper, both unscented Kalman filter and Particle Filter methods of a LiFePO4 battery for applications in electric vehicles were verified using Thevenin equivalent circuit model. Compared with the extended Kalman filter method, results show that both unscented Kalman filter and particle filter have a better estimation accurancy.
2016, 5(1):33-43. DOI: 10.12146/j.issn.2095-3135.201601004
Abstract:CUDA(Compute Unified Device Architecture) has a complex thread organization and multilevel memory modules, which makes it difficult to quantitatively evaluate time complexity of CUDA-based algorithms. In this paper, a Hierarchical Memory Machine (HMM) Model was investigated to solve this problem. HMM is a theoretical parallel computing model, which is capable of representing the essence of computing and memory structures on the GPU(Graphics Processing Units) devices. Based on the proposed HMM model, a parallel algorithm was presented for the approximate string matching problem. The proposed algorithm is evaluated and compared with existing approaches, to show a speedup ratio of more than 60.
2016, 5(1):44-47. DOI: 10.12146/j.issn.2095-3135.201601005
Abstract:An analytical method based on high performance liquid chromatography was developed for analysis of nerol, linalool and citronellol, which are three main monoterpenes in essential oils. The optimized chromatographic conditions were determined as: C18 column (4.6 mm i.d.×150 mm, 5 μm), acetonitrile/water (v/v, 1∶1) as mobile phase, UV detector (205 nm), flow rate at 1.0 mL/min. The precision and stability of the method were also validated. This method is of high sensitivity, good reproducibility, and meets the methodological requirements. Furthermore, the methodology has been applied to detect the content of nerol, linalool and citronellol in rose oil, rose essence, lemon oil and lemon essence.
2016, 5(1):48-56. DOI: 10.12146/j.issn.2095-3135.201601006
Abstract:Recently, with the development of human-computer interaction, interactive projection technologies have been used more and more extensively, which is able to perceive the ambient behavior by using additional sensors and corresponding projected contents for interacting, such as augmented reality, structured light coding, and 3D reconstruction. Touch-sensitive interactive projection has achieved broad prospects on embedded human-machine system in the future. This paper aims at realizing bare-hand touch interaction on arbitrary surfaces by means of a camera and a projector. The performance of this system can be achieved through three steps, foreground extraction, fingertip detection and touch detection. Extensive experiments are presented to show the accurate and robust performance of our approach.
2016, 5(1):57-67. DOI: 10.12146/j.issn.2095-3135.201601007
Abstract:Obtaining the iris localization precisely and fast is the prelude of effective iris recognition. Traditional iris localization methods, including Daugman localization and Hough transformation localization, are weak in processing images with thick eyelashes and severely shlter. In this paper, combined with previous work of other researchers, deep learning method was employed to classify iris images based on the characteristics of iris region. We carried our experiment on the CASIA-IrisV3-Interval dataset, to verify the effectiveness of our work. The accuracy of pixel-wise classification is around 98.4%, with a higher robustness.
2016, 5(1):68-74. DOI: 10.12146/j.issn.2095-3135.201601008
Abstract:At present, imbalanced data classification is the research hotspot of machine learning. Traditional machine learning classification algorithms are usually used on balanced datasets, which cannot be directly applied to the imbalanced data. A new kind of imbalanced boosting algorithm based on feature selection was proposed to balance the importance for the minority class samples from different types of attributes of datasets, which not only could select the more meaningful attributes for the prediction of the minority class samples, but also reduce data dimension. Then, the imbalanced boosting algorithm was combined to make the datasets balanced. Finally, since the wrong sample weight of the original algorithm grew fast, a new algorithm which could restrain the growths of sample weight effectively was put forward. Experimental results show that the proposed algorithm can effectively improve the classification performance of imbalanced datasets, especially that of the minority class.
2016, 5(1):75-84. DOI: 10.12146/j.issn.2095-3135.201601009
Abstract:Using robotic surgery system in the transpedicular screw path drilling would be helpful for alleviating the burden of surgeons and guarantee the correctness, stability and safety of operations. Focusing on transpedicular fixation operation, the robotic spinal surgical system RSSS-II was designed and developed. Firstly, a 6 degree of freedoms in-serial surgery robotic arm and a bone drilling device with force sampling were designed to meet the requirements of spinal surgeries, such as the operational safety, the range of the operation area, the positioning of patient and installation space issues. Secondly, for the precise control of robot in positioning and path drilling process, some key technologies were studied and then the image navigation system was built. Finally, the safety, accuracy and feasibility of developed robotic spinal surgery system RSSS-II we demonstrated through series of experiments. The experimental results show that the accuracy of the system can satisfy the clinical requirement.
2016, 5(1):85-90. DOI: 10.12146/j.issn.2095-3135.201601010
Abstract:In current marine low-temperature distillation seawater desalination plant, an ejector is designed to pump gas and water synchronously so as to reduce device size and energy consuming. In this paper, an ejector design scheme with two stages was investigated. Flow field characteristic of the proposed ejector was simulated to demonstrate that this design could increase inlet flow velocity and pressure which in turn could improve inlet vacuum and decrease vacuum. Real experiments were also carried out to validate the simulated results. The experimental results show that, when the flow velocity is larger than 3.5 m/s, vacuum at ejector suction can reach 92% and 90% respectively and meet the performance requirements of marine ejector.