Preliminary clinical application of an adaptive iterative statistical reconstruction algorithm inhead and neck computed tomography angiography with low tube voltage and a low concentration of contrast medium

Objective To evaluate the feasibility of using a low concentration of contrast medium （Visipaque 270 mgl/mL）, low tube voltage, and an advanced image reconstruction algorithm in head and neck computed tomography angiography （CTA）. Methods Forty patients （22 men and 18 women; average age 48.7 ± 14.25 years; average body mass index 23.9 ± 3.7 kg/m^2） undergoing CTA for suspected vascular diseases were randomly assigned into two groups. Group A （n = 20） was administered 370 mgl/mL contrast medium, and group B （n = 20） was administered 270 mgl/mL contrast medium. Both groups were administered at a rate of 4.8 mL/s and an injection volume of 0.8 mL/kg. Images of group A were obtained with 120 kVp and filtered back projection （FBP） reconstruction, whereas images of group B were obtained with 80 kVp and 80% adaptive iterative statistical reconstruction algorithm （ASiR）. The CT values and standard deviations of intracranial arteries and image noise on the corona radiata were measured to calculate the contrast-to-noise ratio （CNR） and signal-to-noise ratio （SNR）. The beam-hardening artifacts （BHAs） around the skull base were calculated. Two readers evaluated the image quality with volume rendered images using scores from 1 to 5. The values between the two groups were statistically compared. Results The mean CT value of the intracranial arteries in group B was significantly higher than that in group A （P 〈 0.001）. The CNR and SNR values in group B were also statistically higher than those in group A （P 〈 0.001）. Image noise and BHAs were not significantly different between the two groups. The image quality score of VR images of in group B was significantly higher than that in group A （P = 0.001）. However, the quality scores of axial enhancement images in group B became significantly smaller than those in group A （P〈 0.001）. The CT dose index volume and dose-length product were decreased by 63.8% and 64%, respectively, in group B （P 〈 0.001 for both）. Conclusion Visipaque combined with 80 kVp and 80% ASiR provided similar image quality in intracranial CTA with 64% radiation dose reduction compared with the use of lopamidol, 120 kVp, and FBP reconstruc-tion.

Analysis of the Factors Influencing the Participation of University Students in Rural Education for Poverty Alleviation

The principle of“poverty alleviation first helps the poor”is fundamental to poverty alleviation through education in rural areas.It serves as an important foundation for improving the soft power of rural culture and promoting the development of rural cultural construction.However,college students,being one of the main participants in educational poverty alleviation,have not been equipped with a well-established institutionalized participation mechanism and a sufficient awareness of participation.To enhance college students’awareness and participation in rural education and poverty alleviation and to improve the institutionalization,this research focuses on college students as a group,delves into the current situation and willingness of college students to participate in rural education and poverty alleviation,and analyzes the influencing factors affecting college students’participation in rural education and poverty alleviation by means of a questionnaire and a computerized statistical algorithm.Lastly,based on mathematical and statistical analysis,the research puts forward corresponding optimization countermeasures and suggestions from the perspectives of the government,colleges and universities,and villages,so as to provide decision-making guidelines for solving the problems of rural education development and talent constraints.

DESIGN OF SPARSE ARRAY FOR MAD IMAGING BASED ON MAXIMIZING INFORMATION CAPACITY

In past years,growing efforts have been made to the rapid interpretation of magnetic field data acquired by a sparse synthetic or real magnetic sensor array.An appealing requirement on such sparse array arranged within a specified survey region is that to make the number of sensor elements as small as possible,meanwhile without deteriorating imaging quality.For this end,we propose a novel methodology of arranging sensors in an optimal manner,exploring the concept of information capacity developed originally in the communication society.The proposed scheme reduces mathematically the design of a sparse sensor array into solving a combinatorial optimization problem,which can be resolved efficiently using widely adopted Simultaneous Perturbation and Statistical Algorithm(SPSA).Three sets of numerical examples of designing optimal sensor array are provided to demonstrate the performance of proposed methodology.

Distinction of self-synchronous scrambled linear blockcodes based on multi-fractal spectrum

This study proposes a novel multi-fractal spectrumbasedapproach to distinguish linear block codes from its selfsynchronousscrambled codes. Given that the linear block codeand self-synchronous scrambled linear block code share the propertyof linear correlation, the existing linear correlation-basedidentification method is invalid for this case. This drawback can becircumvented by introducing a novel multi-fractal spectrum-basedmethod. Simulation results show that the new method has highrobustness and under the same conditions of bit error, the lowerthe code rate, the higher the recognition rate. Thus, the methodhas significant potential for future application in engineering.

Energy Saving Model and Calculation Example of Three Cooling Schemes for Data Center in Hot Summer and Cold Winter Area

In order to achieve the goal of “carbon peak” in 2030 and “carbon neutralization” in 2060, the task of energy conservation has risen to the national strategic level, and its work is urgent. It focuses on energy saving and energy consumption in data center, 5G network and other fields. The gravity heat pipe double cycle air conditioning is a kind of room air conditioning which uses natural cooling source with high efficiency. According to the outdoor meteorological parameters of ten typical cities in China, the calculation model of unit hybrid refrigeration mode is established by using integral method. A simplified algorithm for statistical summation is proposed. Then it compares with the same type of refrigerant pump air conditioner, water-cooled chiller and natural cooling plate. The results show that the annual operation time of gravity heat pipe double cycle air conditioner is 50.8% longer than that of refrigerant pump air conditioner. Then the calculation model is verified by the annual actual operation data of a data center in Changsha. The results show that the double cycle air conditioner with gravity heat pipe can save about 34% energy compared with the chiller. The accuracy of the calculation model is 17.5%, which meets the engineering accuracy requirements. The application of gravity heat pipe double cycle air conditioning in hot summer and cold winter area is a scheme worthy of popularization and application.