Study on the Influence of Piloti on Mean Radiant Temperature in Residential Blocks by 3-D Unsteady State Heat Balance Radiation Calculation

Piloti is commonly used in tropical and subtropical climate zones to get high wind velocity and create shadowed areas in order to optimize the living environment of residential blocks,but there are few studies to reveal the influence of piloti on the radiant environment of residential blocks systematically. Taking the city of Guangzhou as an example,using 3-D Unsteady State Heat Balance Radiation Calculation Method,this paper shows that the mean radiant temperature( MRT) under piloti area increases with the increase of piloti ratio,and especially when piloti ratio is equal to 100%,the MRT increase trend becomes sharp. The MRT of exposed area decreases with the increase of piloti ratio,especially when piloti ratio reaches 100%,the decrease trend of MRT becomes sharp,which offers the reference for the study on piloti design in subtropical climate zones and further research on living environment by CFD simulation in residential blocks.

Statistical Model of the 3-D Braided Composites Strength

Based on the statistical model for the tensile statistical strength of unidirectional composite materials and the stress analysis of 3-D braided composites, a new method is proposed to calculate the tensile statistical strength of the 3-D braided compos- ites. With this method, the strength of 3-D braided composites can be calculated with very large accuracy, and the statistical parameters of 3-D braided composites can be determined. The numerical result shows that the tensile statistical strength of 3-D braided composites can be predicted using this method.

Predication of 3-D Viscous Flowfield of a Centrifugal Impeller

A three-dimensional viscous code has been developed to solve Reynolds-averaged Navier-Stokes equations. The governing equations in finite volume form are solved by two-step Runge-Kutta scheme with implicit residual smoothing. The eddy viscous is obtained using the Baldwin-Lomax model. A prediction of the 3-D turbulent flow and the performance in the “all-over controlled vortex distribution” centrifugal impeller with a vaneless diffuser has been made for the compressor at design and off-design condition. The predicted effi-ciency is a little higher than the experiment data. These results suggest that the present calculation code is able to determine the flow development in the impeller and also the turbulence model in the centrifugal im-peller should be improved.

Scattering of seismic waves by three-dimensional large-scale hill topography simulated by a fast parallel IBEM

To solve seismic wave scattering by a large-scale three-dimensional(3-D) hill topography, a fast parallel indirect boundary element method(IBEM) is developed by proposing a new construction method for the wave field, modifying the generalized minimum residual(GMRES) algorithm and constructing an Open MP plus MPI parallel model. The validations of accuracy and efficiency show that this method can solve 3-D seismic response of a large-scale hill topography for broadband waves, and overcome the weakness of large storage and low efficiency of the traditional IBEM. Based on this new algorithm architecture, taking the broadband scattering of plane SV waves by a large-scale Gaussian-shaped hill of thousands-meters height as an example, the influence of several important parameters is investigated, including the incident frequency, the incident angle and the height-width and length-width ratio of the hill. The numerical results illustrate that the amplification effect on the ground motion by a near-hemispherical hill is more significant than the narrow hill. For low-frequency waves, the scattering effect of the higher hill is more pronounced, and there is only a single peak near the top of the hill. However, for high-frequency waves, rapid spatial variation of displacement amplitude appears on the hill surface.

The impact of intensity modulated radiotherapy on the skin dose for deep seated tumors

Objective: The purpose of this study was to investigate the impact of intensity modulated radiotherapy (IMRT) on surface doses for brain, abdomen and pelvis deep located tumors treated with 6 MV photon and to evaluate the skin dose calculation accuracy of the XIO 4.04 treatment planning system. Methods: More investigations for the influences of IMRT on skin doses would increase its applications for many treatment sites. Measuring skin doses in real treatment situations would reduce the uncertainty of skin dose prediction. In this work a pediatric human phantom was covered by a layer of 1 mm bolus at three treatment sites and thermoluminescent dosimeter (TLD) chips were inserted into the bolus at each treatment site before CT scan. Two different treatment plans [three-dimensional conformal radiation therapy (3DCRT) and IMRT] for each treatment sites were performed on XIO 4.04 treatment planning system using superposition algorism. Results: The results showed that the surface doses for 3DCRT were higher than the surface doses in IMRT by 1.6%, 2.5% and 3.2% for brain, abdomen and pelvis sites respectively. There was good agreement between measured and calculated surface doses, where the calculated surface dose was 15.5% for brain tumor calculated with 3DCRT whereas the measured surface dose was 12.1%. For abdomen site the calculated surface dose for IMRT treatment plan was 16.5% whereas the measured surface dose was 12.6%. Conclusion: The skin dose in IMRT for deep seated tumors is lower than that in 3DCRT which is another advantage for the IMRT. The TLD readings showed that the difference between the calculated and measured point dose is negligible. The superposition calculation algorism of the XIO 4.04 treatment planning system modeled the superficial dose well.

伽玛刀治疗计划系统GAMMA-TPS的研制

伽玛刀治疗计 划系统是 伽玛 刀的 重 要组 成部 分。 Ｇ Ａ Ｍ Ｍ Ａ Ｔ Ｐ Ｓ 是专 为瑞 典 Ｌ Ｅ Ｋ Ｓ Ｅ Ｌ Ｌ 伽 玛刀而 研制的高性能 真 三维 治 疗计 划 系 统。它 有两 部 分 组 成， 基于 ４８６ 微 机 和 多媒 体 卡 的 Ｗ Ｉ Ｎ Ｄ Ｏ Ｗ Ｓ 风格图象 采集系统和基 于 Ｓ Ｇ Ｉ Ｉ Ｎ Ｄ Ｉ Ｇ Ｏ２ 图形工作 站主计 划系统 。 Ｇ Ａ Ｍ Ｍ Ａ Ｔ Ｐ Ｓ 具有美 观的 图形界面；能自 动或交互提取体 表、病灶及敏感 组织的轮廓 线；具有 逼真的 基于体 积和 表面的 三维结 构重建和显示 功能；可 自动 规 划焦 点数 目 与焦 点位 置， 自动 保护 敏 感组 织（ 堵塞 源 孔自 动 计算） ，也可在三个正 交切面内依据等 剂量线人机 交互 排布与 调整 焦点， 并用 Ｂｅａ ｍ ’ｓ Ｅｙｅ Ｖｉｅ ｗ 验 证或 人工堵塞源孔； 可对剂量最大点 或任 意参 考点开 出剂 量处 方，系 统自 动计 算每 一焦 点的 治疗 时间 ；计 划评估采用体 积剂量分布、体积 剂量直方图、等 剂量线、等剂量 面、剂量 参数统 计表 等验证 手段 ；治 疗计划和验证 结果以图文 形式 打印 输出。文 中给 出一 个病 例，具 体展 示本 治疗 计划 系统 的实 际临床使用情况 。

间隔旁路射频消融15例分析

目的： 总结１５ 例间隔旁路的射频消融结果。方法： 将间隔旁路区分为前间隔旁路，左、右中间隔旁路以及左、右后间隔旁路； 然后对不同部位旁路的射频消融方法进行分析。结果： 前间隔旁路１ 例、左中间隔旁路１ 例、右中间隔旁路２ 例、左后间隔旁路６ 例及右后间隔旁路５ 例。所有病例均一次消融成功， 均未发生房室传导阻滞； ２ 例左后间隔旁路在冠状静脉窦内消融成功。随访２ 个月～３８ 个月， 无心动过速复发。结论： 射频导管消融术是阻断间隔旁路的安全有效的方法。

基于笔射束核阵列的三维适形剂量计算

目的:介绍一种基于笔射束核阵列的方法在剂量计算中的应用。方法:通过对由测量数据反解卷积获取的笔射束核阵列做进一步处理,得到拟合笔射束核。利用光通分布与笔射束核卷积得到射野剂量的分布,将拟合核和标准核计算的目标射野的剂量值与测量值进行比较。结果:与常规笔射束核相比,改进后的笔射束核应用于卷积模型中计算剂量分布,对模型的计算准确度有较大的提高。结论:改进后的笔射束核能够有效的提高卷积模型的计算精度,更为精确的预测射野的剂量分布。

Similarity-Based 3-D Atmospheric Nucleation Data Visualization and Analysis

Atmospheric nucleation is a process of phase transformation, which serves a significant role in many atmospheric and technological processes. To simulate atmospheric nucleation activities, certain molecular models with three-dimensional （3-D） structures are generated. Analyzing these 3-D molecular models can help promote understanding of nucleation processes. Unfortunately, the ability to understand atmospheric nucleation processes is greatly restricted due to lack of efficient visual data exploration tools. In this paper, we present a data visualization solution to visualize and classify 3-D molecular crystals. We developed a novel algorithm for calculating similarity between the 3-D molecular crystals, and further improved the overall system performance with GPU （graphics processing unit） acceleration.