Scandinavian Thins on Top of Cake: New and Improved Algorithms for Stacking and Packing

We show how to compute the smallest rectangle that can enclose any polygon, from a given set of polygons, in nearly linear time; we also present a PTAS for the problem, as well as a linear-time algorithm for the case when the polygons are rectangles themselves. We prove that finding a smallest convex polygon that encloses any of the given polygons is NP-hard, and give a PTAS for minimizing the perimeter of the convex enclosure. We also give efficient algorithms to find the smallest rectangle simultaneously enclosing a given pair of convex polygons.     

支持多种手机客户端的校园信息发布系统

针对数字化校园建设中存在的信息孤岛问题,设计开发了基于客户服务架构的能支持多种手机客户端的校园信息发布系统。分析了系统功能,描述了系统拓扑结构和软件架构,对数据交换接口、网页和手机客户端信息提醒等关键技术进行了探讨。试用结果表明系统运行良好,达到了设计目的。     

过烧YAG陶瓷晶界的分析

采用固相反应法用不同的烧结速率在1850℃烧结合成过烧钇铝石榴石（YAG）陶瓷，YAG陶瓷晶界形貌随烧结速率的变化而不同。高纯的毋Al2O3和Y2O3原料粉体经高能球磨在1400℃空气中煅烧，生成主相为YAG相的多相粉体化合物。真空烧结YAG陶瓷时烧结速率800℃／h并在1850℃真空烧结4h会使陶瓷中晶粒长大不充分，晶粒与晶粒之间仍保留明显的面接触，陶瓷内部残存大量直径约1μm的气孔，尺寸与可见光波长接近，对透过率的影响大，陶瓷成半透明；在以100~C／h升至1850℃真空烧结4h的YAG多晶陶瓷半透明化，陶瓷晶粒粗大，晶界宽化且保留熔融态凝固，用TEM及EDS确认晶界处存在毋α-Al2O3和钙钛型YAP共晶相。     

Woodification: User‐Controlled Cambial Growth Modeling

We present a botanical simulation of secondary (cambial) tree growth coupled to a physical cracking simulation of its bark. Whereas level set growth would use a fixed resolution voxel grid, our system extends the deformable simplicial complex (DSC), supporting new biological growth functions robustly on any surface polygonal mesh with adaptive subdivision, collision detection and topological control. We extend the DSC with temporally coherent texturing, and surface cracking with a user‐controllable biological model coupled to the stresses introduced by the cambial growth model.     

Bayesian network models for environmental flow decision‐making: 1. Latrobe River Australia

Current methods underpinning environmental flow (eFlow) decisions often lack transparency, do not adequately consider uncertainties and rarely include adaptive management principles. We report the development and application of an eFlow Bayesian Network (BN) model that links four flow components with an ecological model to predict the spawning and recruitment of two important native fish species, the Australian Grayling and River Blackfish, in the highly regulated and flow‐stressed lower Latrobe River in Victoria, Australia. Autumn high flows, in conjunction with low stream temperature, are critical for Grayling spawning. The BN model was used to predict the probability of spawning and recruitment of these two native fish species for four flow scenarios. Quantitative data, flow simulation models and expert judgement were used to parameterize the BN model. The model results showed clearly that currently, and into the future, there is a very low likelihood of spawning and recruitment of Australian Grayling in the lower Latrobe. River Blackfish are minimally affected by the predicted reductions in flow and increased stream temperatures. Management scenarios aimed at modifying flows and stream temperatures to increase the likelihood of successful spawning and recruitment of Australian Grayling were assessed. Self‐sustaining populations of Australian Grayling could conceivably be achieved in the upper reaches of this river if fish passage was provided through an on‐stream reservoir. A major benefit in building and applying an eFlow BN model is that it can facilitate meaningful analysis and discussion of the ecological effects of particular eFlow regimes. Copyright © 2010 John Wiley & Sons, Ltd.     

The effect of piezoresistive microcantilever geometry on cantilever sensitivity during surface stress chemical sensing

We have designed, fabricated, and tested five piezoresistive cantilever configurations to investigate the effect of shape and piezoresistor placement on the sensitivity of microcantilevers under both point loading and surface stress loading. The experimental study reveals that: (1) high aspect ratio cantilevers that are much longer than they are wide are optimal for point-loading applications such as microscopy and force measurements; (2) low aspect ratio cantilevers that are short and wide are optimal for surface stress-loading scenarios such as those that occur in biological and chemical sensor applications. The sensitivity data for both point loads and surface stress are consistent with previously developed finite-element models.     

Practical Interdomain Routing Security

This article reviews risks and vulnerabilities in interdomain routing and best practices that can have near-term benefits for routing security. It includes examples of routing failures and common attacks on routers, and countermeasures to reduce router vulnerabilities.     

The effect of polyethylene thickness in fixed- and mobile-bearing total knee replacements

In this paper fixed- and mobile-bearing implants were simulated using a multibody dynamic model and a finite element model to investigate the contact pressure distribution in the ultra high molecular weight polyethylene tibial bearing component. The thickness of polyethylene varied from 6.8 to 12.3 mm and the polyethylene was modelled as a non-linear material. It was found that the contact pressure on the polyethylene decreased in the fixed-bearing implant when the thickness of polyethylene increased from 6.8 to 8 and 9.6 mm, but there was little further decrease in pressure with the increase of polyethylene thickness from 9.6 to 11.0 and 12.3 mm. In the mobile-bearing implant, no increase in contact pressure on the superior surface was found with the increase in the thickness of the polyethylene; however, the contact pressures on the inferior contact surface of the thicker designs were higher than those in the 6.8 mm design. The numerical results obtained in this paper are in good agreement with published experimental test results. Moreover, the paper presents a detailed pressure distribution on the tibial bearing component during a full gait cycle.     

The role of anergy in peripheral T cell unresponsiveness

When a T cell's encounter with specific antigen results in good signaling through the T cell antigen receptor yet does not lead to a proliferative response, the T cell enters a state of nonresponsiveness, or anergy. Anergy induction can result from a number of different situations, including antigen presentation by costimulation-deficient or "non-professional" antigen presenting cells, pharmacological blocking of T cell proliferation, or chronic stimulation of the T cell receptor by antigen. Anergy is a long-lived but temporary state characterized by a profound inability of the T cell to produce IL-2. Other effector functions may be affected to variable degrees. Anergy has been characterized most carefully under in vitro conditions, but several experimental models have demonstrated that T cells can also become anergic in vivo. This mechanism for tolerance induction may help to ensure that any mature autoreactive T cells which escape thymic deletion are unable to respond to host tissues. Furthermore, an understanding of the mechanism of anergy induction will most certainly lead to beneficial clinical applications, including improving graft acceptance and avoiding such deleterious immune responses as autoimmunity and allergy.     

Interaction of transport resistances with biochemical reaction in packed-bed solid-state fermentors: effect of temperature gradients

Subdermal superficial liposuction, first presented by the authors at the ISAPS Congress at Zurich in 1989, is performed with thin three-hole Mercedes cannulas (diameter ranges from 1.8 to 2 mm) to treat small and secondary adiposities and to allow better skin retraction. Suction of the subdermal layer of fat reduces the thickness and consistency of the superficial fat and enhances the possibility of skin retraction. In cases where there is a large adiposity of the abdomen, arms, or inner thighs, there is a conspicuous volume of fat whose weight tends to overstretch and to carry the overlying skin downward. In these cases we need to reduce the large fat volume to permit effective skin retraction. Therefore, we apply the principles of traditional liposuction with those of subdermal superficial liposuction to aspirate large amounts of fat from all the adipose layers. We call this technique Massive All Layer Liposuction (MALL). The amount of skin shrinkage after this "defatting" procedure is remarkable and the clinical results are very good. The MALL technique can be applied to other areas as well. In our experience this new liposuction technique has dramatically reduced the indications of abdominoplasties and dermolipectomies of inner thighs and arms.