Cross-Layer Resource Allocation in Multi-interface Multi-channel Wireless Multi-hop Networks

Wei Feng,Suili Feng,Yongzhong Zhang3,Xiaowei Xia 한국전자통신연구원 2014 ETRI Journal Vol.36 No.6

In this paper, an analytical framework is proposed forthe optimization of network performance through jointcongestion control, channel allocation, rate allocation,power control, scheduling, and routing with theconsideration of fairness in multi-channel wireless multihopnetworks. More specifically, the framework modelsthe network by a generalized network utilitymaximization (NUM) problem under an elastic link datarate and power constraints. Using the dual decompositiontechnique, the NUM problem is decomposed into foursubproblems — flow control; next-hop routing; rateallocation and scheduling; power control; and channelallocation — and finally solved by a low-complexitydistributed method. Simulation results show that theproposed distributed algorithm significantly improves thenetwork throughput and energy efficiency compared withprevious algorithms.

PAIR OF (GENERALIZED-)DERIVATIONS ON RINGS AND BANACH ALGEBRAS

Wei, Feng,Xiao, Zhankui Korean Mathematical Society 2009 대한수학회보 Vol.46 No.5

Let n be a fixed positive integer, R be a 2n!-torsion free prime ring and $\mu$, $\nu$ be a pair of generalized derivations on R. If < $\mu^2(x)+\nu(x),\;x^n$ > = 0 for all x $\in$ R, then $\mu$ and $\nu$ are either left multipliers or right multipliers. Let n be a fixed positive integer, R be a noncommutative 2n!-torsion free prime ring with the center $C_R$ and d, g be a pair of derivations on R. If < $d^2(x)+g(x)$, $x^n$ > $\in$ $C_R$ for all x $\in$ R, then d = g = 0. Then we apply these purely algebraic techniques to obtain several range inclusion results of pair of (generalized-)derivations on a Banach algebra.

Postoperative Radiotherapy Improves Survival in Gastric Signet-Ring Cell Carcinoma: a SEER Database Analysis

Wei, Feng,Lyu, Hongwei,Wang, Shuoer,Chu, Yan,Chen, Fengyuan The Korean Gastric Cancer Association 2019 Journal of gastric cancer Vol.19 No.4

Purpose: To identify the potential therapeutic role of postoperative radiotherapy (RT) in patients with locally advanced (stage II and stage III) gastric signet ring cell carcinoma (SRC). Materials and methods: Patients with locally advanced gastric SRC from the Surveillance, Epidemiology, and End Results program database between 2004 and 2012 were included in our study. Univariate and multivariate Cox proportional models were performed, and survival curves were generated to evaluate the prognostic effect of postoperative RT and surgery alone on SRC patients. Propensity score matching (PSM) was used to avoid selection bias among the study cohorts. Results: We found that patients with postoperative RT had better probability of survival compared with those who did not receive RT (overall survival [OS], P<0.001; cancer-specific survival [CSS], P<0.001). After PSM, analysis of both overall and CSS showed that patients who underwent postoperative RT had better prognosis than those receiving surgery alone in the matched cohort (OS, P=0.00079; CSS, P=0.0036). Multivariate Cox proportional model indicated that postoperative RT had better effect on prognosis compared with surgery alone with respect to both overall (hazard ratio [HR], 0.716; 95% confidence interval [95% CI], 0.590-0.87; P=0.001) and CSS (HR, 0.713; 95% CI, 0.570-0.890; P=0.003). Conclusions: Postoperative RT had better prognosis compared with surgery alone for both overall and CSS for patients with locally advanced gastric SRC.

Multi-objective optimization of process parameters for the helical gear precision forging by using Taguchi method

Wei Feng,Lin Hua 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.6

Precision forging of the helical gear is a complex metal forming process under coupled effects with multi-factors. The various process parameters such as deformation temperature, punch velocity and friction conditions affect the forming process differently, thus the optimization design of process parameters is necessary to obtain a good product. In this paper, an optimization method for the helical gear precision forging is proposed based on the finite element method (FEM) and Taguchi method with multi-objective design. The maximum forging force and the die-fill quality are considered as the optimal objectives. The optimal parameters combination is obtained through S/N analysis and the analysis of variance (ANOVA). It is shown that, for helical gears precision forging, the most significant parameters affecting the maximum forging force and the die-fill quality are deformation temperature and friction coefficient. The verified experimental result agrees with the predictive value well, which demonstrates the effectiveness of the proposed optimization method.

GENERALIZED JORDAN TRIPLE HIGHER DERIVATIONS ON SEMIPRIME RINGS

Wei, Feng,Xiao, Zhankui Korean Mathematical Society 2009 대한수학회보 Vol.46 No.3

In this paper we prove that every generalized Jordan triple higher derivation on a 2-torsion free semiprime ring is a generalized higher derivation. This extend the main result of [9] to the case of a semiprime ring.

Research of the Rice Image Segmentation Based on Color Linear Array CCD

Weifeng Zhong,Yaji Xie,Xiaoxi He 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.11

Using color linear array CCD (Charge Coupled Device) to collect the information of image has an important meaning in the research of the machine vision processing. It now becomes the focus of study on CCD image acquisition using FPGA (Field Programmable Gate Array) to implement color linear array CCD-driven design. The image acquisition and processing of the rice color sorter as the research background in this paper, by using FPGA to achieve the color linear array CCD driven control, as well as simulated with Quartus II 8.0. In order to be able to extract the color linear array CCD output useful information of the color images, through study the RGB model and the HSI (Huge, Saturation, Intensity) model of color space model, the HSI space mode is selected as the color image processing space model, and design the suitable algorithm-FCM (Fuzzy C-Means) clustering algorithm in HSI space for color image segmentation, through a fuzzy Toolbox in MATLAB to accomplish the FCM algorithm, at the same time, through the simulation realized the FCM algorithm. The simulation shows that the algorithm can segment the image useful information well.

GENERALIZED WEIGHTED COMPOSITION OPERATORS FROM AREA NEVANLINNA SPACES TO WEIGHTED-TYPE SPACES

Weifeng, Yang,Weiren, Yan Korean Mathematical Society 2011 대한수학회보 Vol.48 No.6

Let $H(\mathbb{D})$ denote the class of all analytic functions on the open unit disk $\mathbb{D}$ of the complex plane $\mathbb{C}$. Let n be a nonnegative integer, ${\varphi}$ be an analytic self-map of $\mathbb{D}$ and $u{\in}H(\mathbb{D})$. The generalized weighted composition operator is defined by $$D_{{\varphi},u}^nf=uf^{(n)}{\circ}{\varphi},\;f{\in}H(\mathbb{D})$$. The boundedness and compactness of the generalized weighted composition operator from area Nevanlinna spaces to weighted-type spaces and little weighted-type spaces are characterized in this paper.

An Intelligent Framework of Oral Examination System under Network Environment and Its Application

Weifeng MA,Xiaoyong SUN 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.12

As a crucial step in the process of teaching and training, examination, especially oral examination, is characterized with such defects as excessive subjectivity, difficult organization, low efficiency and heavy pressure. Thus, network technology and computer technology are employed to further promote the informationization of traditional oral examination. Through analyzing the existing problems of traditional oral examination and the feasibility of oral examination under network environment, this paper puts forward a universal framework and management model for oral examination under network environment and designed an oral examination system based on digital voice technology, artificial intelligence and software engineering. The research findings have been applied to mandarin Chinese test. So far Over 10 organization users have adopted the system and more than 300,000 examinees have been tested. Viewed from the practice, expected effects have been achieved.

FOCCX: An Optimistic Concurrency Control Protocol over XML

Weifeng Shan,Husheng Liao 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.2

XML concurrency control protocol (CCP) is used to guard the consistence and isolation of transactions in Native XML databases. Experiments show that locking overhead of existing approaches based on locking may be huge, especially in the applications with few or without conflicts. Optimistic concurrency control (OCC) is an alternative to locking. This paper presents a new optimistic approach for concurrency control over XML documents named FOCCX (Forward oriented Optimistic Concurrency Control over XML) facing XPath-based API. FOCCX increases the degree of transaction concurrency. This is achieved by aborting the current transaction when a potential UPDATE-UPDATE conflict taking place as early as possible, and reduces comparison times by checking a small write set against read set of a limited number of concurrent transactions. Experimental results show that our protocol has superior performance to approaches based on Backward Oriented mechanism (BOCC).

Modified Subtraction Coronary CT Angiography with a Two-Breathhold Technique: Image Quality and Diagnostic Accuracy in Patients with Coronary Calcifications

Weifeng Guo,Pratik Tripathi,Shan Yang,Juying Qian,Bimal Rai,Meng-Su Zeng 대한영상의학회 2019 Korean Journal of Radiology Vol.20 No.7

Objective: To evaluate a modified subtraction coronary computed tomography angiography (CCTA) technique with a twobreathhold approach in terms of image quality and stenosis grading of calcified coronary segments and in the detection of significant coronary stenosis in segments with severe calcification. Materials and Methods: The Institutional Review Board approved this study, and all subjects provided written consent. A total of 128 patients were recruited into this trial, of which 32 underwent subtraction CCTA scans and invasive coronary angiography (ICA). The average Agatston score was 356 ± 145. In severely calcified coronary segments, the presence of significant (> 50%) stenosis was assessed on both conventional CCTA and subtraction CCTA images, and the results were finally compared with ICA findings as the gold standard. Results: For severely calcified segments, the image quality in conventional CCTA significantly improved from 2.51 ± 0.98 to 3.12 ± 0.94 in subtraction CCTA (p < 0.001). In target segments, specificity (70% vs. 87%; p = 0.005) and positive predictive value (61% vs. 79%; p < 0.01) were improved using subtraction CCTA in comparison with conventional CCTA, with no loss in the negative predictive value. The segment-based diagnostic accuracy for detecting significant stenosis was significantly better in subtraction CCTA than in conventional CCTA (area under the receiver operating characteristic curve, 0.94 vs. 0.85; p = 0.03). Conclusion: This modified subtraction CCTA method showed lower misregistration and better image quality in patients with limited breathhold capability. In comparison with conventional CCTA, modified subtraction CCTA would allow stenosis regrading and improve the diagnostic accuracy in coronary segments with severe calcification.