Rendering of Surface and Volume Details in Volume Data*

Aiming at the detail rendering in volume data, a new volume illumination model, called Composed Scattering Model (CSM), is presented. In order to enhance different details in volume data, scattering intensity is decomposed into volume scattering intensity and surface scattering intensity with different weight functions. According to the Gauss probability distribution of gray and gradient of data, we propose an accurate method to detect the materials in a voxel, called composed segmentation. In addition, we discuss the principle of constructing these weight functions based on the operators defined in composed segmentation. CSM can generate images containing more details than most popular volume rendering models. This model has been applied to the direct volume rendering of 3D data sets obtained by CT and MRI. The resultant images show not only rich details but also clear boundary surfaces. CSM is demonstrated as an accurate volume rendering model suited for detail enhancement in volume data sets.     

Potential thread-level-parallelism exploration with superblock reordering

The growing number of processing cores in a single CPU is demanding more parallelism from sequential programs. But in the past decades few work has succeeded in automatically exploiting enough parallelism, which casts a shadow over the many-core architecture and the automatic parallelization research. However, actually few work was tried to understand the nature, or amount, of the potentially available parallelism in programs. In this paper we will analyze at runtime the dynamic data dependencies among superblocks of sequential programs. We designed a meta re-arrange buffer to measure and exploit the available parallelism, with which the superblocks are dynamically analyzed, reordered and dispatched to run in parallel on an ideal many-core processor, while the data dependencies and program correctness are still maintained. In our experiments, we observed that with the superblock reordering, the potential speedup ranged from 1.08 to 89.60. The results showed that the potential parallelism of normal programs was still far from fully exploited by existing technologies. This observation makes the automatic parallelization a promising research direction for many-core architectures.     

公路路面施工质量研究

多年来，各种公路路面出现了损坏现象，施工队伍对路面基层缺少足够的重视，施工工艺达不到规定的要求，对施工中路面的质量重视程度不够。所以要求具有科学性的路面施工技术，制定科学的施工方案，保证公路的路面施工质量达到标准规定。     

A reconfigurable processor architecture combining multi-core and reconfigurable processing units

It’s a promising way to improve performance significantly by adding reconfigurable processing unit (RPU) to a general purpose processor. In this paper, a Reconfigurable Multi-Core (RMC) architecture combining general multi-core and reconfigurable logic is proposed. Reconfigurable logic is separated into RPUs logically, which are coupled with general purpose cores as co-processors via a full crossbar switch. An RPU Manager (RPU-M) is also designed to manage RPUs. To verify RMC, a simulation method based on the Simics and Virtex 5 FPGA is adopted, which simplifies the simulation and assures the evaluation accuracy of hardware function cores. Five workloads are selected to test RMC, including 3-DES, AES, SHA2, IDCT and JPEG_ENC. The experimental results show a 3.10 times average speedup over software implementation on the original multi-core, and the data and control communication overhead on RMC is acceptable.     

摇摆条件下圆管内过冷沸腾局部空泡时空分布特性

过冷流动沸腾在核能、动力、化工等工业领域广泛存在,局部空泡分布特性的准确预测对构建两相流数理模型及两相流动压降和传热特性计算均具有重要意义。实验借助光学探针测量手段研究摇摆条件下圆管内过冷沸腾局部空泡分布特性,并提出多周期同相位叠加方法获得摇摆运动条件下局部瞬时空泡份额。实验结果表明:摇摆条件下圆管内局部空泡分布呈现周期性波动规律,摇摆条件下圆管轴心区及近壁区均会出现局部空泡份额峰值,且流道近壁区局部空泡份额波动幅度最大;与静止条件下不同,摇摆运动周期内过冷沸腾局部空泡份额空间分布形态随时间发生变化;摇摆周期和摇摆角度对过冷沸腾局部空泡分布特性也存在一定影响。     

石面坦水电站灯泡式水轮发电机冷却系统的改造

灯泡式水轮发电机的二次循环冷却系统的冷却水的冷却，多是通过炮泡体的冷却锥套表面与河水进行热交换的方式。石面坦、永兴、马骝滩、渭沱等水电站的灯泡贯流水轮发电机组，在刚投入运行时其发电机冷却 系统的冷却效果较好，但运行一段时间后，在其冷却锥套外壁都附着一层厚3－5mm的类似污泥或类似水垢的物质或水生物。对冷却锥套的热交换效果影响很大，致使发电机的运行温度升高，每年都需要组织人员进行清除。后经改造成敞开械循环冷却供水系统，取得了较好的效果。     

孜拉山1888 m无垂深超长水平孔钻进关键技术

西藏昌都孜拉山隧道勘察水平孔设计深度1500 m,实际完钻深度1888.88 m。钻进过程中强风化破碎带地层孔壁易坍塌,硬岩地层超长水平孔钻孔轨迹控制难度大,绳索取心岩心管和打捞器推送困难,提下钻阻力大、回转扭矩大、钻具磨损严重,局部地层涌水、冲洗液漏失频发,严重影响成孔质量、施工效率和施工成本。分析了无垂深水平孔钻进过程中破碎地层孔壁失稳、钻孔轨迹偏移、钻进扭矩大、钻具磨损严重等问题产生的原因,给出了实钻过程中的解决方案和处理措施,顺利完成钻孔施工任务,积累了无垂深水平孔绳索取心钻进复杂问题处理措施和经验。     

一种路由协议构件的特征量化方法和应用

由于构件具有动态和可复用的特点，实现了路由协议构件，抽象出协议构件的特征参数，从而实现了基于构件的智能路由器方案。突出的特点是灵活的实现、良好的分布式特性以及强大的适应能力。     

Cost Minimization with HPDFG and Data Mining for Heterogeneous DSP

Cost minimization and execution-time reduction have become the most important issues in today’s real-time embedded system. Meanwhile, for the DSP (Digital Signal Processing) applications running on embedded system, loops inside them are the most critical part for performance optimization. To optimize the loop iteration patterns, we need to schedule the loop execution order. Due to the uncertainties within the execution time of tasks, we model varied execution times of tasks as random variables and propose a novel data graph model, called HPDFG (Heterogeneous Probabilistic Data-Flow Graph) to model DSP applications on embedded systems. A novel algorithm, LSHAPE, is proposed to minimize the cost and satisfy the timing constraints. First of all, we use the data mining methods to estimate the probabilistic distribution of the execution time variables. Second, we rotate the loops in the application to explore different possible execution patterns. Finally, we combine the list-scheduling and the dynamic programming to generate a near-optimal task allocation and a core-mode assignment. Experimental results demonstrate the effectiveness of our algorithm. Our approach can handle loops efficiently.     

Preparation of composite anion exchange membranes based on in-situ copolymerization of N-vinyl formamide and divinylbenzene in porous PTFE

A series of composite anion exchange membranes was synthesized via in-situ copolymerization of various ratios N-vinyl formamide (NVF) and divinylbenzene (DVB), supported by porous polytetrafluoroethylene (PTFE) polymer matrix, and followed by alkaline hydrolysis, and quaternization of the composite membranes with epoxypropyltrimethylammonium chloride (EPTMAC). FTIR and SEM analyses revealed that the composite membranes were successfully prepared. Moreover, the hydrophilic property of the composite membrane improved by introduction of the quaternized poly(NVF-co-DVB) copolymer. Water uptake, swelling ratio, and conductivity showed upward trends by increase of NVF amount. The copolymer with 95% of NVF showed the highest elongation at break (102%, room temperature) and conductivity (5.15 × 10⁻² S/cm, 80°C). After immersion of the PNDB_95%-N membrane in 5 mol/L NaOH solution for 96 h at room temperature, the conductivity (60°C) of the membrane decreased to 3.99 × 10⁻² S/cm. Moreover, the membrane registered weight loss under 4.5%, caused by degradation of the quaternary ammonium groups in NaOH solution. All in all, in 3 mol/L methanol solutions, the composite membranes showed permeability ranging from 7.6% to 19.7%, if compared to the Nafion®-115 membrane, showing good alcohol resistance.