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Search Results: 1 - 10 of 45852 matches for " Lei Feng "
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Identification and Calculation Method of the Financial Benefits of IT Projects for Better Financial Evaluation  [PDF]
Jingchun Feng, Fujie Zhang, Lei Li
Intelligent Information Management (IIM) , 2010, DOI: 10.4236/iim.2010.29063
Abstract: To financially evaluate an IT projects is to assess its financial feasibility, while the financial benefits are the core parameters of financial evaluation of IT projects. Therefore, correctly identifying the financial benefits of IT projects is the precondition to ensure the validity of the financial evaluation. Essentially, IT projects can be divided into productive IT projects and supportive IT projects. The paper analyzes the importance of identifying the financial benefits and introduces the meaning, characteristics and classification of financial benefits of IT projects. On this basis, the paper identifies the financial benefits of both productive IT projects and supportive IT projects and emphasizes the formation and specific calculation method of the two types of IT projects. For productive IT projects and supportive IT projects, the calculation of financial benefits should employ different methods.
Performance of HARQ in Device-to-Device Communication  [PDF]
Wenji Feng, Yafeng Wang, Lei Yang
Communications and Network (CN) , 2013, DOI: 10.4236/cn.2013.53B2061
Abstract: In this paper, we study D2D (Device-to-Device) communication underlying LTE-Advanced uplink system. Since D2D communication reuses uplink resources with cellular communication in this scenario, it’s hard for D2D users to avoid the interference from cellular users while cellular users are communication with eNB (evolved Node B). HARQ (Hybrid Automatic Repeat reQuest) is widely used in LTE-Advanced system in order to improve the accurate rate of cellular communication. Hence, we consider studying the integration of D2D with HARQ, so as to achieve the purpose of improving the throughput of D2D communication and the performance of overall system. Synchronous HARQ is considered to introduce into D2D communication procedures. What’s more, this idea will be taken into system-level simulation. From the simulation results, we can see that the throughput of D2D communication gets a lot of gain and the performance of overall system is improved as well. In addition, Synchronous HARQ technique can significantly decrease the BLER (Block Error Rate) of D2D communication, especially for which in a bad channel condition.
Resource Allocation Method of Device-to-Device Communication  [PDF]
Wenji Feng, Yafeng Wang, Lei Yang
Communications and Network (CN) , 2013, DOI: 10.4236/cn.2013.53B2062
Abstract: In this paper, we study D2D (Device-to-Device) communication underlying LTE-Advanced uplink system. Since D2D communication reuses uplink resources with cellular communication in this scenario, it’s hard to avoid the inference between D2D users and cellular users. If there is no restriction for D2D communication on using the whole uplink frequency band, it will have a strong negative impact on cellular communication. In order to overcome this shortage, we propose a resource allocation method that D2D users and cellular users use orthogonal frequency resources. This method will effectively reduce the inference between both kinds of communication. However, an obvious disadvantage of this method is no effective use of uplink resources. Based on this, we propose an optimized resource allocation method that a specific cellular user will be chosen to reuse the RBs (Resource Block) of D2D users. These ideas will be taken into system-level simulation, and from the results of simulation we can see that the optimized method has the ability to improve overall system performance and limit inference for cell-edge users.
Kikuchi Fujimoto disease associated with cryptogenic organizing pneumonia: case report and literature review
Feng Hua, Lei Zhu
BMC Infectious Diseases , 2010, DOI: 10.1186/1471-2334-10-64
Abstract: A 33-year-old male presented with a 1-month cough illness and fever lasting for 5 days. The chest radiograph revealed double lower lobe infiltrate, which was unresponsive to antibiotics. A cervical lymph node was first found in the development of this disease. Bronchoscopy, bronchoalveolar lavage and lung biopsy established the diagnosis of COP, while a lymph node biopsy was consistent with KFD. The patient improved on steroids.KFD and COP are possible part of a disease continuum, rather than separate entities.Cryptogenic organizing pneumonia (COP) is an interstitial lung disease characterized by intra-alveolar buds of connective tissue [1]. It can be idiopathic or associated with a known underlying disease.In this case report, we present a 33-year-old man with COP, followed by concomitant Kikuchi Fujimoto disease (KFD). KFD was first described in 1972 by Kikuchi and Fujimoto and others. It is a clinicopathological entity that commonly presents with cervical lymphadenopathy and fever in the absence of an active infectious disease. KFD is a rare histiocytic necrotizing lymphadenitis, which has a benign self-limiting clinical course. Its origin is unknown, but an abnormal autoimmune reaction has been suggested and infection is often considered as an inducing feature [2].To the best of our knowledge, this is the first case report of COP and KFD.A 33-year-old man presented with a 1-month coughing illness and fever that lasted for 5 days. Before admission, the patient experienced expectoration of yellow sputum and antibiotic therapy for 2 weeks. There was no history of fever, rash or respiratory distress, and there was no family history of autoimmune or connective tissue disorders. Respiratory examinations revealed fine crackles in both lungs. Examination of other systems was unremarkable.The laboratory investigation showed hemoglobin 140 g/L, leukocytes 3.9 × 109/L with a normal differential count, platelets 142 × 109/L, C-reactive protein 1.2 mg/L, and an erythrocyte s
Decaying Asymmetric Dark Matter Relaxes the AMS-Fermi Tension
Feng, Lei;Kang, Zhaofeng
High Energy Physics - Phenomenology , 2013,
Abstract: The first result of AMS-02 confirms the positron fraction excess observed by PAMELA, but in the dark matter (DM) interpretation, its softer spectrum brings a tension between AMS-02 and Fermi-LAT, which reported an excess of the electron plus positron flux. In this work we point out that the asymmetric cosmic ray from asymmetric dark matter (ADM) decay relaxes the tension, and find that at the two-body decay level a bosonic ADM around 2.4 TeV and decaying to\mu^-\tau^+ can significantly improve the fits. Based on the R-parity-violating supersymmetry with operators LLE^c, we propose a minimal model to realize that ADM scenario: Introducing a pair of singlets (X,\bar X) and coupling them to the visible sector via LH_uX, we then obtain a leptonic decaying ADM with TeV-scale mass.
Influence of Jieyu Huoxue Decoction on rehabilitation of patients with depression after cerebral infarction
FENG Bei-Lei
Zhong Xi Yi Jie He Xue Bao , 2004,
Abstract: Objective: To study the influence of Jieyu Huoxue Decoction on rehabilitation of patients with depression after cerebral infarction. Methods: Fifty four patients suffered from the depression after acute cerebral infarction were randomly divided into three groups: depression control group, fluoxetine treated group and Jieyu Huoxue Decoction treated group. Eighteen patients of cerebral infarction without depression were enrolled in the no depression control group randomly. The Zung self-rating depression scale (SDS), the modified Edinburgh-Scandinavia stroke scale (MESSS) and the activities of daily living (ADL) were evaluated before treatment, 30 and 60 days after treatment. Results: After 30 and 60 days of treatment, SDS evaluation of the Jieyu Huoxue Decoction treated group showed significant difference as compared with the condition before treatment and that of the depression control group (P<0.05 or P<0.01), MESSS evaluation and ADL evaluation also showed significant difference as compared with the condition before treatment and that of the depression control group (P<0.05 or P<0.01); there was no obvious difference between the fluoxetine treated group and the Jieyu Huoxue Decoction treated group, but the Jieyu Huoxue Decoction treated group showed fewer symptoms and less side effect. Conclusion: Jieyu Huoxue Decoction can not only relieve depression after cerebral infarction, but also improve neurological functions.
Evaluation of Urban Park Service Quality Based on Factor Analysis
Yichuan Zhang,Lei Feng
International Journal of Computer Science Issues , 2012,
Abstract: Urban park is an important component of urban public green space which provides leisure, recreation, activity place, etc. Urban park service quality was evaluated by quantitative method in this paper to provide scientific evidence for renewal and development of urban park. 5 urban parks in Xinxiang, Henan province, China were selected as evaluation samples, and 13 indexes were evaluated, including plant landscape, cultural experience, activity place, ecological environment, road design, topographical management, fitness facilities, water landscape, service facility, night landscape, landscape aesthetics, information mark and shelter landscape. Then the data were analyzed by factor analysis. Results: the information contained in the 13 evaluation indexes had considerable repeatability. Therefore, 5 main factors including landscape elements, sports and entertainment, cultural quality, ecology and night scene and traffic facilities were extracted which accounted for 80.881% of total variation. The number of factor variables was far less than the number of index variables, which reduced the complexity of evaluation and indicated that factor analysis had good dimension-reducing effect. Based on the results of factor analysis, not only the contribution rate of each index and each factor in the park service quality evaluation, but also single factor scores and comprehensive scores in different parks could be obtained, which facilitated the analysis and comparison of service quality of different parks. Our work can provide support for urban park renewal, reconstruction and development, thereby promoting the urban park service quality.
Robustness Measure of China’s Railway Network Topology Using Relative Entropy
Fenling Feng,Lei Wang
Discrete Dynamics in Nature and Society , 2013, DOI: 10.1155/2013/391709
Abstract: This study focused on China’s railway network topology issue from a robustness measure perspective. Relative entropy is used in the study as a measurement of robustness of railway network topology. It is found that the entropy-based measure provides more informative analyses compared to a traditional graph measure. The results indicate that the railway network in the 12th five-year plan has improved robustness when compare to 2008 with respect to deliberate and random attacks. 1. Introduction Since China’s first railway was built in 1865, there have been tremendous achievements in its development over 145 years. Many new stations and lines were constructed; a huge network has been formed. The planning of a railway network should not only be evaluated from external indexes, but also analyzed on its overall performance. The research on railway network topology structure takes the railway network as a complicated system and studies its topology structure using statistical methods, to provide a theoretical basis and foundation for network planning, construction, and scientific research. The robustness of network topology is one of the most important and basic features of complicated systems. Research on robustness is based primarily on graph theory, which includes average shortest path, node degree, aggregation coefficient, and the number of interfaces. But these measures of robustness do not offer adequate amounts of information. This article uses relative entropy as the robustness measure of China’s railway network topology. It also analyzes the relationship of relative entropy and ordering employing information theory methods from a systematic view. The robustness of China’s railway network in 2008 and in the 12th five-year plan was analyzed. At present, in robustness research of network topology, scholars usually take definitions from graph theory as measures of robustness. Albert et al. [1] compared the connectivity of random networks and scale-free networks (a typical complex network) and further pointed out that the robustness of the two networks is significantly different under random attacks and malicious attacks. Watts [2] and Strogatz [3] put forward the concept of small world networks. Cohen et al. [4] found the robustness of an Internet network under random attacks and malicious attacks is based on Percolation theory. Bollobas and Riordan [5] made a mathematical analysis for robustness complex networks based on random graph theory. And Bars et al. [6] proposed a robustness measure in accordance with the Gastinel-Kahan theorem investigating
A New Equation of State for Dark Energy Model
Lei Feng,Tan Lu
Physics , 2012, DOI: 10.1088/1475-7516/2011/11/034
Abstract: A new parameterization for the dark energy equation of state(EoS) is proposed and some of its cosmological consequences are also investigated. This new parameterization is the modification of Efstathiou' dark energy EoS parameterization. $w (z)$ is a well behaved function for $z\gg1$ and has same behavior in $z$ at low redshifts with Efstathiou' parameterization. In this parameterization there are two free parameter $w_0$ and $w_a$. We discuss the constraints on this model's parameters from current observational data. The best fit values of the cosmological parameters with $1\sigma$ confidence-level regions are: $\Omega_m=0.2735^{+0.0171}_{-0.0163}$, $w_0=-1.0537^{+0.1432}_{-0.1511}$ and $w_a=0.2738^{+0.8018}_{-0.8288}$.
Decaying Asymmetric Dark Matter Relaxes the AMS-Fermi Tension
Lei Feng,Zhaofeng Kang
Physics , 2013, DOI: 10.1088/1475-7516/2013/10/008
Abstract: The first result of AMS-02 confirms the positron fraction excess observed by PAMELA, but the spectrum is somewhat softer than that of PAMELA. In the dark matter (DM) interpretation it brings a tension between AMS-02 and Fermi-LAT, which reported an excess of the electron plus positron flux. In this work we point out that the asymmetric cosmic ray from asymmetric dark matter (ADM) decay relaxes the tension. It is found that in the case of two-body decay a bosonic ADM around 2.4 TeV and decaying into $\mu^-\tau^+$ can significantly improve the fits. Based on the $R-$parity-violating supersymmetry with operators $LLE^c$, we propose a minimal model to realize that ADM. The model introduces only a pair of singlets $(X,\bar X)$ with a tiny coupling $LH_uX$, which makes the ADM share the lepton asymmetry and decay into $\mu^-\tau^+$ along the operator $LLE^c$.
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