Improved SLIC Segmentation Algorithm for Artificial Structure Images

Simple linear iterative cluster(SLIC) is widely used because controllable superpixel number, accurate edge covering, symmetrical production and fast speed of calculation. The main problem of the SLIC algorithm is its under-segmentation when applied to segment artificial structure images with unobvious boundaries and narrow regions. Therefore, an improved clustering segmentation algorithm to correct the segmentation results of SLIC is presented in this paper. The allocation of pixels is not only related to its own characteristic, but also to those of its surrounding pixels.Hence, it is appropriate to improve the standard SLIC through the pixels by focusing on boundaries. An improved SLIC method adheres better to the boundaries in the image is proposed, by using the first and second order difference operators as magnified factors. Experimental results demonstrate that the proposed method achieves an excellent boundary adherence for artificial structure images. The application of the proposed method is extended to images with an unobvious boundary in the Berkeley Segmentation Dataset BSDS500. In comparison with SLIC, the boundary adherence is increased obviously.

Casting structure of pure aluminum by electric pulse modification at different superheated temperatures

Electric pulse modification （EPM） is a novel technique that reduces grain size by altering the structure of a melt. It was investigated that the response of the casting structure of high pure aluminum to EPM in different superheated melts. The results indicate that the grain refining effect of a given pulse electric field holds an optimal temperature range, moreover, a lower or higher superheated temperature will both disadvantage the improvements of casting structure. It essentially lies in the cooperative action between the distorted absorption of clusters and the activated capability of atoms in the aluminum melt.

Electro-Pulse on Improving Steel Ingot Solidification Structure

Pulse Electric Discharging (PED) is a novel technique that can modify solidifying structure and reduce grain size. ItS effectsapplied to the high carbon liquid steel were presented here. The macrostructure and microstructure of the high carbon alloy steel werealso observed. Results show that (1 ) the length of columnar crystal at the edge of ingot without PED treatment is much longer than thatwith PED, and (2) the perlite lamellae of steel billets after deposed by PED are twisted and shortened. An explanation of those experimental results is given.

Parameter Identification and Application of Slippage Kinematics for Tracked Mobile Robots

A new parameter identification method is proposed to solve the slippage problem when tracked mobile robots execute turning motions.Such motion is divided into two states in this paper:pivot turning and coupled turning between angular velocity and linear velocity.In the processing of pivot turning,the slippage parameters could be obtained by measuring the end point in a square path.In the process of coupled turning,the slippage parameters could be calculated by measuring the perimeter of a circular path and the linear distance between the start and end points.The identification results showed that slippage parameters were affected by velocity.Therefore,a fuzzy rule base was established with the basis on the identification data,and a fuzzy controller was applied to motion control and dead reckoning.This method effectively compensated for errors resulting in unequal tension between the left and right tracks,structural dimensions and slippage.The results demonstrated that the accuracy of robot positioning and control could be substantially improved on a rigid floor.

African swine fever virus MGF505-3R inhibits cGAS-STING-mediated IFN-βpathway activation by degrading TBK1

African swine fever virus(ASFV)is an important pathogen causing acute infectious disease in domestic pigs and wild boars that seriously endangers the global swine industry.As ASFV is structurally complex and encodes a large number of functional proteins,no effective vaccine has been developed to date.Thus,dissecting the mechanisms of immune escape induced by ASFV proteins is crucial.A previous study showed that the ASFV-encoded protein is an important factor in host immunity.In this study,we identified a negative regulator,MGF505-3R,that significantly downregulated cGAS/STING-and poly(dG:dC)-mediated IFN-βand interferon stimulation response element(ISRE)reporter activity and suppressed IFNB1 and IFIT2 mRNA levels.In addition,TBK1,IRF3 and IκBαphosphorylation levels were also inhibited.Mechanistically,MGF505-3R interacted with cGAS/TBK1/IRF3 and targeted TBK1 for degradation,thereby disrupting the cGAS-STING-mediated IFN-βsignaling pathway,which appears to be highly correlated with autophagy.Knockdown MGF505-3R expression enhanced IFN-βand IL-1βproduction.Taken together,our study revealed a negative regulatory mechanism involving the MGF505-3R-cGAS-STING axis and provided insights into an evasion strategy employed by ASFV that involves autophagy and innate signaling pathways.

Pulsation Treatment on the Modification of Crystal with Cold Simulation

Since the separation of crystal of KCl saturated aqueous is similar to the crystallization of liquid metals, the melts nucleation can be simulated by the experiment of the crystal of salt aqueous solution. In this experiment pulsation treatment was imposed on KCl saturated aqueous in order to study the effect of pulsation treatment on crystallization in the salt solution, and the influence of different pulsation treating time, super-heating and bine of prescription were investigated. The results show that it is possible to modify the crystallization over satured solution temperature and the degree of under-cooling for salt crystal separation was reduced by applying pulse treating on KCl saturated aqueous solution. In addition, this technology may generate embryos for nucleation even at the temperature over melting point or satured solubility.

Head Motion Detection in Gaze Based Aiming

Unmanned weapons have great potential to be widely used in future wars.The gaze-based aiming technology can be applied to control pan-tilt weapon systems remotely with high precision and efficiency.Gaze direction is related to head motion,which is a combination of head and eye movements.In this paper,a head motion detection method is proposed,which is based on the fusion of inertial and vision information.The inertial sensors can measure rotation in high-frequency with good performance,while vision sensors are able to eliminate drifts.By combining the characteristics of both sensors,the proposed approach achieves the effect of highfrequency,real-time,and drift-free head motion detection.The experiments show that our method can smooth the outputs,constrain drifts of inertial measurements,and achieve high detection accuracy.

An experiment study of osteogenesis of Ad-VEGF165 transfected human bone marrow mesenchymal stem cells in vitro

Objective ：To evaluate the effect of osteogenic potential on human marrow mesenchymal stem cells （hMSCs） transferred with human vascular endothelial growth factor（VEGF） gene by adenovirus, methods：hMSCs were isolated from human marrow, cultured in vitro and randomly divided into 3 groups ：Ad-VEGF165 group： adding 1×10^10 OPU/ml Ad-VEGF in hMSCs culture fluid after incubating 24 hours, changing into ordinary complete culture and continuing culturing; Positive control group： Cultured hMSCs with 1 nmol/L dexamethasone, 10 mmol/L glycerophosphate and 50 mg/L vitamin C ,exchanging this conditioned medium twice a week; blank control group：no special treatment but culturing hMSCs in DMEM.To evaluate osteogenesis competence, Von Kossa＇s staining and a quantitative alkaline phosphates （ALP） activity analysis were performed after 2 weeks treatment. Results：The calcified nodes formed after 2 weeks treatment in Ad-VEGF165 group and Positive control group but not in blank control group. ALP activities in Ad-VEGF165 group ,Positive control group and blank control group were （7.91 ± 0.90）u/L, （8.18 ± 0.76 u/L） and （3.46 ± 0.49）u/L respectively. The differences were no statistical significance between Ad-VEGF165 group and positive control group （P 〉 0.05）, but Ad-VEGF165 group and Positive control group were significantly different with blank control group （P 〈 0.05）. Conclusion：Adenovirus mediated VEGF165 gene can transfect hMSCs and promote osteogenesis of hMSCs.

Management of Intelligent Campus Wireless Sensor Networks Based on Runtime Model

To quick customize and develop intelligent campus internet of things (ICIOT) system more efficiently, in this paper an approach based on runtime model to managing intelligent campus wireless sensor networks is proposed. Firstly, manageability of intelligent campus wireless sensors is abstracted as runtime models which automatically and immediately propagate any observable runtime changes of target resources to corresponding architecture models. Then, a composite model of intelligent campus wireless sensors is constructed through merging their runtime models in order to manage different kinds of devices in a unified way. Finally, a customized model is constructed according to the personalized management requirement and the synchronization between the customized model and the composite model is ensured through model transformation. Thus, all the management tasks can be carried through executing operating programs on the customized model. In the part of the teaching area schools conducted experiments and compared with the traditional method, this method can be more effective management of campus facilities, more energy efficient and orderly, which can reach a 16.7% energy saving.

Improved Research on Fuzzy Search over Encrypted Cloud Data Based on Keywords

A search strategy over encrypted cloud data based on keywords has been improved and has presented a method using different strategies on the client and the server to improve the search efficiency in this paper. The client uses the Chinese and English to achieve the synonym construction of the keywords, the establishment of the fuzzy-syllable words and synonyms set of keywords and the implementation of fuzzy search strategy over the encryption of cloud data based on keywords. The server side through the analysis of the user’s query request provides keywords for users to choose and topic words and secondary words are picked out. System will match topic words with historical inquiry in time order, and then the new query result of the request is directly gained. The analysis of the simulation experiment shows that the fuzzy search strategy can make better use of historical results on the basis of privacy protection for the realization of efficient data search, saving the search time and improving the efficiency of search.

Effect of Sintering Time on the Mechanical and Corrosion Behavior of Zn-Mg Composites with a Core-Shell Structure Prepared by SPS

Zn-10 Mg composite with a core-shell structure was prepared by spark plasma sintering(SPS)technology,and a systematic study of the microstructure and properties has been conducted for different sintering times.The shell layer dominated by the hard MgZn2 phase thickens with the increase in sintering time,which has a positive effect on the mechanical and degradation properties of the material.The sample sintered for 20 min(T-20)has the best mechanical properties,with a compressive strength of 226 MPa and a compression rate of 6.5%.The corrosion resistance of samples increases as the sintering time prolongs,while the hydrogen evolution volume and pH value decrease in the immersion experiment.Furthermore,the increase in the shell thickness significantly reduces the corrosion rate,which is attributed to the weakening of the galvanic corrosion reaction between the Mg core and the MgZn2 shell.Therefore,composite with unique core-shell structure provides an advanced design idea for degradable biomaterials,and a reasonable control of sintering time can provide the optimal design strategy.

30K温区百瓦级二级斯特林制冷机

30 K温区大冷量回热式低温制冷机在超导冷却、气体液化等领域具有广阔的应用前景.相较于其他类型的低温制冷机,斯特林制冷机具有结构紧凑、降温速率快、效率高等优势.基于理论分析和数值计算结果研制了一台大冷量二级斯特林制冷机,并对其开展了初步的实验研究.对不同工况下制冷机的压力波特性以及室温端换热器的换热特性进行研究,发现提高充气压力,压缩腔的压力振幅会提高,室温端换热器的换热量提高.提高第二级制冷温度,压缩腔的压力振幅与室温端换热器的换热量减小,且其减小速率均随制冷机第一级热负荷的增加而提高.制冷机无负荷工作时,每提高0.1 MPa充气压力,制冷机第二级制冷温度降至30 K的平均降温速率提高0.72 K/min.在2.6 MPa充气压力时,制冷机第二级可在13.24 min内降至30 K,最终无负荷制冷温度为19.83 K,此时第一级制冷温度为71.2 K.在第一级无热负荷时,该制冷机在30 K时可提供110 W制冷量,相对卡诺效率为10.96%,这是目前国内该类型低温制冷机公开报道的最高性能.

细菌样颗粒——新型乳酸菌表面展示技术及其应用

细菌样颗粒(Bacterium-like particles,BLPs)是一种新型非遗传修饰型乳酸菌表面展示技术,外源蛋白可通过锚钩蛋白锚定于经热酸处理而得的乳酸菌肽聚糖骨架表面,形成空心表面展示颗粒。因其安全性高、表面展示密度大、黏膜递送效率高,又兼有佐剂效应,BLPs广泛应用于黏膜疫苗和黏膜佐剂的开发、病毒抗原的纯化、生物催化剂的制备等领域。本文就BLPs的构建、独特优势、目前的应用及尚需解决的问题等方面进行详细综述,以期展现BLPs新型表面展示平台的广阔应用前景。

Underground Pipeline Surveillance with an Algorithm Based on Statistical Time-Frequency Acoustic Features

Underground pipeline networks suffer from severe damage by earth-moving devices due to rapid urbanization.Thus,designing a round-the-clock intelligent surveillance system has become crucial and urgent.In this study,we develop an acoustic signal-based excavation device recognition system for underground pipeline protection.The front-end hardware system is equipped with an acoustic sensor array,an Analog-to-Digital Converter(ADC)module(ADS1274),and an industrial processor Advanced RISC Machine(ARM)cortex-A8 for signal collection and algorithm implementation.Then,a novel Statistical Time-Frequency acoustic Feature(STFF)is proposed,and a fast Extreme Learning Machine(ELM)is adopted as the classifier.Experiments on real recorded data show that the proposed STFF achieves better discriminative capability than the conventional acoustic cepstrum features.In addition,the surveillance platform is applicable for encountering big data owing to the fast learning speed of ELM.