Horqin sandy land is one of the regions expanded quickly and researched extensively in desertification in China. In past five decades, the desertification research of Horqin sandy land went through three stages: control of shifting sand dune, regionally integrated study of desertification processes, and demonstrative study on control of desertification. A lot of achievements have been made in the processes, dynamic monitoring, and disaster assessing and integrated management of desertification. According to the status quo of research, existent problems and actual situation of Horqin sandy land, the four aspects below need be further studied: the unification and standardization of monitoring and assessing standard of desertification; the experimentation and demonstrative research of the field observation and control measures of soil erosion in farmland; the monitoring, warning and influence assessment of dust storm disaster; the integration and further popularization of the techniques and modes of prevention and control.
Designed a parameter self-tuning PID-controller based on fuzzy control, which can adjust PID-parameters according to error and change-in-error. A simulation study of the system shows that the controller possesses both the precise character of PID controller and the flexible advantage of fuzzy controller. It can eliminate the steady error of the system promptly.
Background Tumor involving the septum pellucidum is uncommon. Surgery as the main therapeutic procedure for this lesion is a challenge to neurosurgeons. We analyzed the clinical characteristics and pathological features of septum pellucidum tumor in 41 patients and compared the curative effects of frontal transcortical, trans-sulcal and interhemispheric transcallosal approaches. Methods Clinical characteristics and the pathological features of septum pellucidum tumor were investigated retrospectively in 41 patients. The differences in postoperative residual rates, extents of tumors and resection of normal brain tissues after use of the three approaches in these patients were analyzed statistically. Results Septum pellucidum tumor is more likely to attack young or middle-aged persons. The tumor mainly presents itself as a central neurocytoma or cerebral low-grade glioma in pathology and manifests as intracranial hypertension clinically. No difference was found in the extent of tumor resection but significant difference in the extent of normal brain tissue resection and in postoperative disability rate among the three approaches. The transcortical approach brought about the most serious injury to brain tissue and the highest disability rate, Whereas the frontal transcallosal approach the lightest injury and the lowest disability rate. The injury to brain tissue and the disability rate brought about by the front trans-sulcus approach were between the above two approaches. Conclusions Operation is still regarded the major treatment for septum pellucidum tumor. Transcallosal and trans-sulcus approaches are fit with the concept of minimally invasive surgery, and transcallosal approach is the first choice for septum pellucidum tumor.
This paper presents the development of 110GHz monolithic low-noise amplifier (LNA) using 100 nm In0.52Al0.48As/In0.53Ga0.47As GaAs metamorphic high electron mobility transistors (MHEMTs) technology. The MHEMT technology features an extrinsic fT of 220GHz and an extrinsic transconduction gm,max of 940mS/mm. The LNA is consisted by 4 stages 2×20um gate width transistors. The amplifier demonstrates a gain of 17.7dB at 110GHz with a noise figure of 4.3dB when biased for high gain, and a noise figure of 3.6dB is achieved with an associated gain of 16.6dB at 110GHz when biased for low-noise figure. The chip area is 2.7mm×1.4mm.
A fractional-integral multiple ordering method was proposed to improve the integral multiple ordering method in material procurements. To illustrate the improvement effect, a new model considering a fractional-integral multiple ordering method was presented to extend the model proposed by Woo, Hsu, and Wu (2001), and a genetic algorithm was developed to resolve the modified model. Finally a numerical study based on the example used by Woo, Hsu, and Wu was presented to illustrate that the proposed model provided a lower or equal joint total relevant cost compared with Woo, Hsu. and Wu's model.
Carbon-carbon double bond functional groups are often protected through a popular bromination/debromination method because of their reactivity. An ultrasonic-enhanced stereoselective debromination of vic-dibromides with metallic zinc powder in aqueous media has been developed, which generates E-alkenes with excellent yields. The reactivity of vic-dibromides decreases in the order of 1,2-dibromo-1,2-diphenylethane>1,2-dibromo- 1-phenylethane> 1,2-dibromo- 1,2-dialkylethane.
Abstract In classification problems, the occurrence of abnormal observations is often encountered. How to obtain a stable model to deal with outliers has always been a subject of widespread concern. In this article, we draw on the ideas of the AdaBoosting algorithm and propose a asymptotically linear loss function, which makes the output function more stable for contaminated samples, and two boosting algorithms were designed, based on two different way of updating, to handle outliers. In addition, a skill for overcoming the instability of Newton's method when dealing with weak convexity is introduced. Several samples, where outliers were artificially added, show that the Discrete L-AdaBoost and Real L-AdaBoost Algorithms find the boundary of each category consistently under the condition where data is contaminated. In real world data sets, we show the effectiveness of suggested algorithms by comparison with other two ensemble learning methods, especially for large dataset.
Various challenging constraints must be satisfied in railway alignment design for topographically complex mountainous regions. The alignment design for such environments is so challenging that exis...
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