Optimum buckling design of composite stiffened panels using ant colony algorithm

Optimal design of laminated composite stiffened panels of symmetric and balanced layup with different number of T-shape stiffeners is investigated and presented. The stiffened panels are simply supported and subjected to uniform biaxial compressive load. In the optimization for the maximum buckling load without weight penalty, the panel skin and the stiffened laminate stacking sequence, thickness and the height of the stiffeners are chosen as design variables. The optimization is carried out by applying an ant colony algorithm (ACA) with the ply contiguous constraint taken into account. The finite strip method is employed in the buckling analysis of the stiffened panels. The results shows that the buckling load increases dramatically with the number of stiffeners at first, and then has only a small improvement after the number of stiffeners reaches a certain value. An optimal layup of the skin and stiffener laminate has also been obtained by using the ACA. The methods presented in this paper should be applicable to the design of stiffened composite panels in similar loading conditions

Open-Category Classification by Adversarial Sample Generation

In real-world classification tasks, it is difficult to collect training samples from all possible categories of the environment. Therefore, when an instance of an unseen class appears in the prediction stage, a robust classifier should be able to tell that it is from an unseen class, instead of classifying it to be any known category. In this paper, adopting the idea of adversarial learning, we propose the ASG framework for open-category classification. ASG generates positive and negative samples of seen categories in the unsupervised manner via an adversarial learning strategy. With the generated samples, ASG then learns to tell seen from unseen in the supervised manner. Experiments performed on several datasets show the effectiveness of ASG.Comment: Published in IJCAI 201

Relaying systems with reciprocity mismatch : impact analysis and calibration

Cooperative beamforming can provide significant performance improvement for relaying systems with the help of the channel state information (CSI). In time-division duplexing (TDD) mode, the estimated CSI will deteriorate due to the reciprocity mismatch. In this work, we examine the impact and the calibration of the reciprocity mismatch in relaying systems. To evaluate the impact of the reciprocity mismatch for all devices, the closed-form expression of the achievable rate is first derived. Then, we analyze the performance loss caused by the reciprocity mismatch at sources, relays, and destinations respectively to show that the mismatch at relays dominates the impact. To compensate the performance loss, a two-stage calibration scheme is proposed for relays. Specifically, relays perform the intra-calibration based on circuits independently. Further, the inter-calibration based on the discrete Fourier transform (DFT) codebook is operated to improve the calibration performance by cooperation transmission, which has never been considered in previous work. Finally, we derive the achievable rate after relays perform the proposed reciprocity calibration scheme and investigate the impact of estimation errors on the system performance. Simulation results are presented to verify the analytical results and to show the performance of the proposed calibration approach

NOMA-enhanced computation over multi-access channels

Massive numbers of nodes will be connected in future wireless networks. This brings great difficulty to collect a large amount of data. Instead of collecting the data individually, computation over multi-access channels (CoMAC) provides an intelligent solution by computing a desired function over the air based on the signal-superposition property of wireless channels. To improve the spectrum efficiency in conventional CoMAC, we propose the use of non-orthogonal multiple access (NOMA) for functions in CoMAC. The desired functions are decomposed into several sub-functions, and multiple sub-functions are selected to be superposed over each resource block (RB). The corresponding achievable rate is derived based on sub-function superposition, which prevents a vanishing computation rate for large numbers of nodes. We further study the limiting case when the number of nodes goes to infinity. An exact expression of the rate is derived that provides a lower bound on the computation rate. Compared with existing CoMAC, the NOMA-based CoMAC not only achieves a higher computation rate but also provides an improved non-vanishing rate. Furthermore, the diversity order of the computation rate is derived, which shows that the system performance is dominated by the node with the worst channel gain among these sub-functions in each RB

Diagnosis and treatment characteristics of radioactive optic neuropathy

AIM: To explore the diagnosis and treatment methods of radioaction-induced optic neuritis(RION)through the clinical dates of 17 patients. <p>METHODS: It was a retrospective case series study. From August 2008 to October 2013, 17 cases(24 eyes)of Rion clinical dates from Chinese PLA General Hospital were studied. The diagnosis methods including visual acuity, pupil, fundus, visual field, fundus fluorescein angiography(FFA), visual electrophysiological testing, and head MRI. To analysis the clinical date of patients with diagnosis of RION by statistical description.<p>RESULTS: The deterioration degree of vision: 13 eyes were classified as Ⅳ, 9 eyes as Ⅲ, 2 eyes as Ⅱ. Ten eyes RAPD(+), visual electrophysiology is extinguished. The retina of 5 eyes showed flame hemorrhages and cotton wool spots exudation. Optic nerve head edema in one eye. T1-weighted MRI enhanced in 19 eyes which showed optic nerve of the intracranial and intratubal segments abnormal changed, optic chiasm and pituitary stalk signal abnormalities and enhancement of the optic nerve. Tortuous optic nerves and rough edges were observed in 5 eyes. Treatment effect: 4 eyes of visual acuity improved, 1 eye from blindness to light perception,1 eye from 0.08 to 0.2, 1 eye from 0.4 to 0.6,1 eye from 0.04 to 0.15, the rest of the cases did not see any improvement.<p>CONCLUSION: The unique clinical manifestation of RION can provide objective basis for clinical diagnosis in time, but there have not been proven any effective treatments

Over-the-air computation for cooperative wideband spectrum sensing and performance analysis

For sensor network aided cognitive radio, cooperative wideband spectrum sensing can distribute the sampling and computing pressure of spectrum sensing to multiple sensor nodes (SNs) in an efficient way. However, this may incur high latency due to distributed data aggregation, especially when the number of SNs is large. In this paper, we propose a novel cooperative wideband spectrum sensing scheme using over-the-air computation. Its key idea is to utilize the superposition property of wireless channel to implement the summation of Fourier transform. This avoids distributed data aggregation by computing the target function directly. The performance of the proposed scheme is analyzed with imperfect synchronization between different SNs. Furthermore, a synchronization phase offset (SPO) estimation and equalization method is proposed. The corresponding performance after equalization is also derived. A working prototype based on universal software radio periphera (USRP) and Monte Carlo simulation is built to verify the performance of the proposed scheme

Leverage Business Analytics and OWA to Recommend Appropriate Projects in Crowdfunding Platform

Nowadays, crowdfunding is becoming more and more popular. Many studies have been published on the crowdfunding platform from different perspectives. However, among all these studies, few are concerned about the recommendation methods, which, in effect, are highly beneficial to crowdfunding websites and the participants. Having considered the situation talked above, this paper works out the several features from the relative projects of user’s current browsing project. Then we give different weights to each feature based on selective attention phenomenon, and adopt the method of OWA operator to calculate the final score of each relative project and accomplish our model by picking out the four projects with different outstanding characteristics. Finally, according to the statistics on China’s famous crowdfunding website, we conducted a group of contrast experiments and eventually testified that our proposed model could, to some extent, help classify and give recommendation effectively. Furthermore, the results of this research can give guidance to the management of crowdfunding websites and they are also very significant advices for the future crowdfunding website development

Therapeutic effects of ciprofloxacin/bushenhuazhuo combination on chronic prostatitis

Purpose: To evaluate the clinical effect of bushenhuazhuo (a Chinese traditional medicine) in combination with ciprofloxacin (an orthodox medicine) in chronic prostatitis (CP) therapy.Methods: A total of 160 patients who suffered from CP and received treatment in the People’s Hospital of Zhengzhou between April 2012 and June 2014 were selected and divided randomly into treatment and control groups, with 80 patients in each group. Control group was given 0.25 g ciprofloxacin hydrochloride tablets twice a day for 4 weeks. In addition to ciprofloxacin administration, patients in the treatment group also received a dose of bushenhuazhuo preparation twice daily for 4 weeks. Clinical outcomes, quality of life as well as lecithin body and white blood cell (WBC) count in expressed prostatic secretions (EPS-WBC) were evaluated.Results: Cure rates in the treatment and control groups were 90 and 72.50 %, respectively; this difference was significant (p &lt; 0.05). Scores for National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI), WBC, and lecithin bodies in the treatment group (8.20 ± 2.20 points, 4.50 ± 1.20 points, and 28.10 ± 2.10 points, respectively) were higher (p &lt; 0.05) than for the control group (12.20 ± 2.20, 6.30 ± 2.20, and 23.30 ± 2.90 points, respectively). The levels of interferon (IFN)-γ and tumour necrosis factor (TNF)-α in the treatment group (26.20 ± 3.30 and 33.80 ± 5.40 mg/L, respectively) were lower than those in the control group (37.70 ± 3.90 and 48.40 ± 3.70 mg/L, respectively), whereas the level of interleukin (IL)-10 in the treatment group (292.60 ± 23.70 mg/L) was higher (p &lt; 0.05) than that in control group (235.80 ± 25.90 mg/L).Conclusion: Ciprofloxacin combined with the Chinese traditional medicine, bushenhuazhuo preparation, demonstrates a marked therapeutic effect in CP. Its mechanism of action may be related to decreased levels of IFN-γ and TNF-α and increased IL-10.Keywords: Bushenhuazhuo, Interferon – γ, Ciprofloxacin, Chronic prostatitis symptom inde