Research on Dimensional Reduction for SURF Algorithm

SURF（Speed-up robust features）算法进行图像特征点匹配时需要循环遍历待匹配图像所有特征点,计算特征点之间的SURF64描述距离,耗时大。本文对SURF算法进行了16维与4维的降维研究。实验结果表明,16维SURF算法性能与64维SURF算法基本相当,但能大幅度降低运算时间;4维运算性能降低较大,不能用于特征点匹配,但4维SUFR描述算法可以扩展到图像的各个像素点,用于ICP算法及图像的稠密匹配。Matching image feature point by SURF（Speed-up robust features） algorithm needs to loop through all feature points on the image to be matched, and compute the sixty-four dimensional distance of SURF between fea-ture points, which will take a long computation time. The sixteen dimensional SURF and four SURF are imple-mented. The experimental results show that the performance of the sixteen dimensional SURF is almost the same as that of the sixty-four dimensional SURF, moreover the sixteen dimensional SURF takes less time than sixty-four dimensional SURF. The performance of four dimensional SURF is much inferior to that of sixty-four dimensional SURF, so it cannot used to match feature point. However the four dimensional description of SURF can be ex-panded to all feature points, which can be applied in ICP algorithm and dense matching algorithm

“一带一路”背景下的国际汉语教材研发——以越南国别化汉语教材编写与推广为例

当前,在\"一带一路\"沿线国家中,越南已经成为中国重要的贸易伙伴。顺应\"一带一路\"建设的需要,加强越南汉语国际教育既是难得的机遇,又是紧迫的挑战。其中教材仍然是基础性问题。对越南目前汉语教材的出版与使用情况进行深入调查,结合\"一带一路\"建设需要,探讨越南国别化汉语教材的编写与推广,对中越\"一带一路\"建设可以起到积极推动作用

Study on Mechanical Property of Silicon Nitride Thin Film and the Application in RF MEMS Switches

氮化硅薄膜具有致密的结构、高强度和良好的耐磨性能,可用于MEMS器件中作为结构部件.本文采用PECVD法制备氮化硅薄膜,对氮化硅薄膜的杨氏模量和硬度进行了测试,并分析了沉积温度、反应气体流量比对薄膜杨氏模量和硬度的影响.应用氮化硅薄膜作为悬梁,制作了射频MEMS开关.Silicon nitride thin film is often used in MEMS devices as structure part because of its high density and strength. The silicon nitride films were prepared by PECVD method. The test of Young’s Modules and hardness on silicon nitride films were carried on. The relationship between Young’s Modules, hardness and deposition temperature, reaction gas flow ratio was analyzed. The RF MEMS switch was fabricated using silicon nitride as fixed-fixed beam.国家自然科学基金资助(60301006);; 福建省科技重点项目资助(2005H029

Design of low-frequency charge pump PLL

设计一款音频范围内的电荷泵锁相环,采用动态d触发器鉴频鉴相器及电流舵差分输入电荷泵。压控振荡器采用了对电容充放电的形式产生震荡波形,实现低频输出。采用HHnEC bCd035工艺并用CAdEnCE软件实现仿真,实现250 kHz频率锁定,锁定时间为80μS,锁定时相位差为75 nS且压控振荡器控制电压纹波为5 MV。A charge pump PLL working in audio frequency was designed,in which a TSPC-PFD and a current steering charge pump were used.In order to get the low frequency,a VCO that get the output wave by charging or discharging the capacity is used.The circuit is designed with HHNEC BCD035 process and the behavior is simulated with Cadence.The locking frequency of 250 kHz was achieved.Its locking time is 80 μs.when it is locked,the phase difference is 75 ns,and the ripple of the VCO control voltage is 5 mV

透析法制备载羟基喜树碱-聚乳酸纳米粒及其理化性质研究

采用直接透析法制备载羟基喜树碱-聚乳酸(HCPT-PLA)纳米粒并研究其理化性质、体外释放和细胞毒性.以HCPT-PLA纳米粒的载药率为评价标准,通过正交设计考察PLA浓度、HCPT与PLA的质量比和不同截留分子质量透析袋对其指标的影响.利用Malvern nano-zs粒度测定仪、XRD、DSC和激光共聚焦显微镜(CLSM)对HCPT-PLA纳米粒的理化性质进行表征.薄膜透析法考察体外释药特性;MTT试验检测细胞毒作用.在优化条件下制备的载药纳米粒为实心球形,平均粒径为226.8 nm,多分散系数为0.270,载药率为7.49%.HCPT是以晶体状态均匀分布于PLA纳米粒中.药物体外释药符合Higuchi方程Q=2.000 6X1/2-2.593 4,r=0.989 2.MTT试验显示HCPT-PLA纳米粒呈现明显细胞毒作用.透析法制备HCPT-PLA纳米粒,粒径小且分布均匀,具有较好的缓释特性;细胞毒性试验表明HCPT-PLA纳米粒具有较强的抑瘤作用且抑瘤效果优于HCPT

Model Reference Fuzzy Adaptive PID Control of Paraffin Oil Level in Capsule Forming Machine

滴丸机定型杯石蜡油液位控制系统是一个存在非线性、参数时变性和耦合性的复杂系统.通过分析建立了该液位系统的数学模型,并且将自适应控制、模糊控制和PID控制结合起来,提出了一种模型参考模糊自适应PID控制方法.该方法无需辨识被控对象参数,实时性好,便于在线控制.仿真结果表明,该方法具有较好的动态品质和调节精度,以及很强的鲁棒性,即使当被控对象参数摄动20%时,依然可以获得理想的控制效果.现场运行实验结果也表明了该方法的有效性.The paraffin oil level control system in capsule forming machine is a nonlineart,ime-variant and coupling system.The mathematical model of the level control system was established.And a new model reference fuzzy adap-tive PID(MRFA-PID)control method was proposed by combining the adaptive control,fuzzy control and PID control techniques.Without need to identify the parameters of the controlled plantt,he proposed method has a good real-time performance,and is easy to be implemented on line.Simulation results show that the proposed method is efficient to design a robust paraffin oil level control system for capsule forming machine with good dynamic character and high regulation precision.Even though the parametersp′erturbation reaches 20%t,he closed-loop system still has satisfied dynamic performance.The effectiveness of the proposed method is also verified by physical experiment.厦门市科技计划资助项目(3502Z2006008

The Study on Mechanical Properties of Thin Film in Micro-electromechanical Systems

主要介绍微机电系统(MEMS)中几种测量薄膜力学性能的方法,如纳米压入法、单轴拉伸法、基底弯曲法、微旋转结构法,比较了各种方法的优缺点。这对MEMS器件的设计与研究具有重要意义。Some methods of measuring mechanical properties of thin film in Micro-electromechanical systems are intro-duced including nanoindentation,single axial tension,wafer curvature,micro rotating structure,etc.Their advantages and disadvantages are compared.It is useful for the design and researchment of MEMS devices.国家基金青年基金(60301006);; 福建省自然科学基金(A0310012);; 国家留学基金项目资

Investigation for Metal Lift-off Process in RF MEMS Switch

研究用bP212正性光刻胶(浸泡氯苯)、AzP4620正性光刻胶(浸泡氯苯)、Az5214E反转光刻胶光刻后的图形剥离金属的难易度及图形质量.用扫描电镜(SEM)观察不同光刻胶及浸泡氯苯后的侧壁图形,并分析不同侧壁图形的形成机理,找出最佳工艺参数,并应用于射频MEMS开关制作中的金属剥离.The lift-off processes of BP212 positive photoresist(and chlorobenzene treatment) and AZP4620 positive photoresist(and chlorobenzene treatment) were studied.AZ5214E image-reversal photoresist was also studied.Side wall graphics were observed using scanning electron microscope(SEM).The forming mechanism of different lateral wall pattern was analysed.The optimum process parameters were found and used in metal lift-off in RF MEMS switches.国家青年基金资助项目(60301006);福建省自然科学基金资助项目(A0310012

Endoscopic Vision Augmentation Using Multiscale Bilateral-Weighted Retinex for Robotic Surgery

医疗机器人手术视觉是微创外科手术成功与否的关键所在。由于手术器械医学电子内镜自身内在的局限性，导致了手术视野不清晰、光照不均、多烟雾等诸多问题，使得外科医生无法准确快速感知与识别人体内部器官中的神经血管以及病灶位置等结构信息，这无疑增加了手术风险和手术时间。针对这些手术视觉问题，本论文提出了一种基于双边滤波权重分析的多尺度Retinex模型方法，对达芬奇医疗机器人手术过程中所采集到的病患视频进行处理与分析。经过外科医生对实验结果的主观评价，一致认为该方法能够大幅度地增强手术视野质量；同时客观评价实验结果表明本论文所提出方法优于目前计算机视觉领域内的图像增强与恢复方法。 厦门大学信息科学与技术学院计算机科学系罗雄彪教授为本文第一作者。【Abstract】Endoscopic vision plays a significant role in minimally invasive surgical procedures. The visibility and maintenance of such direct in-situ vision is paramount not only for safety by preventing inadvertent injury, but also to improve precision and reduce operating time. Unfortunately, endoscopic vision is unavoidably degraded due to illumination variations during surgery. This work aims to restore or augment such degraded visualization and quantitatively evaluate it during robotic surgery. A multiscale bilateral-weighted retinex method is proposed to remove non-uniform and highly directional illumination and enhance surgical vision, while an objective noreference image visibility assessment method is defined in terms of sharpness, naturalness, and contrast, to quantitatively and objectively evaluate endoscopic visualization on surgical video sequences. The methods were validated on surgical data, with the experimental results showing that our method outperforms existent retinex approaches. In particular, the combined visibility was improved from 0.81 to 1.06, while three surgeons generally agreed that the results were restored with much better visibility.The authors thank the assistance of Dr. Stephen Pautler for facilitating the data acquisition, Dr. A. Jonathan McLeod and Dr.Uditha Jayarathne for helpful discussions

FIBER-REINFORCED COPPER MATRIX COMPOSITES FABRICATED BY ELECTROCHEMICAL INFILTRATION TECHNIQUE

［中文文摘］基于电化学浸渗技术(ECI)在室温下制备了连续铜纤维、碳纤维和玻璃纤维增强铜基复合材料。实验结果表明,在本实验工艺条件下可获得致密的纤维/Cu基复合材料,并具有优良的力学性能。复合材料的断口形貌及显微结构的SEM观察表明,纤维与铜基体之间的界面结合良好,纤维不受任何损伤。证实了ECI在室温下快速制备纤维增强金属基复合材料的可行性。［英文文摘］Continuous-fiber-reinforced Cu matrix composites were fabricated based on the electrochemical infiltration technique (ECI). The experimental results show that the dense fiber/Cu composites have been obtained on the present condition, which possess good mechanical properties. The fracture surface morphology and microstructures of the composites have been observed by SEM. It is indicated that the interfacial bond between fibers and Cu matrix is very well and the fibers do not have any damage. The ECI is　feasible to prepare rapidly fiber reinforced metal matrix composites at room temperature