走向新平衡——浅议“标志性”建筑与“普通性”建筑间的关系

随着城市的发展和国际化的进程,越来越多以“高、大、新、奇”为特点的建筑物营运而生。它们彼此争当“主角”,争当所谓的“标志性建筑”,而不甘沦为“普通性建筑”。就目前的城市面貌来看,这两种建筑之间无论在数量、位置、还是二者的空间关系上,都存在着只有对抗、缺乏对话、难以平衡的关系。如何使“标志性”建筑与“普通性”建筑间走向新的平衡,成为当今城市面临的一个严峻问题。

What we should know about portal vein thrombosis in cirrhotic patients:A changing perspective

Portal vein thrombosis(PVT) is one of the most common complications occurring during the natural course of liver cirrhosis.Even though PVT is often asymptomatic,the worsening of liver function,an unexpected episode of gastrointestinal bleeding or ascitic decompensation may be landmarks of PVT development.Beyond these clinical manifestations,it is debated whether PVT really has an impact on liver cirrhosis natural history or rather represents only one of its consequences.Probably PVT development should not only be considered as a matter of impaired blood flow or pro-coagulation tendency.On one hand,PVT seems a consequence of the worsening in portal vein outflow due to the increased hepatic resistance in cirrhotic livers.On the other hand,vascular microthrombosis secondary to necroinflammation may cause liver ischemia and infarction,with loss of hepatic tissue(parenchymal extinction) which is replaced by fibrotic tissue.Therefore,PVT might also be considered as the overt manifestation of the liver fibrosing process evolution and anticoagulant therapy may thus have microscopic indirect effects also on the progression of liver disease.At present,a connection between PVT development and the progression of liver fibrosis/cirrhosis has not yet been demonstrated.Nevertheless,it is not clear if PVT development may worsen cirrhotic patients' outcome by itself.Some authors tried to assess liver transplant benefit in PVT cirrhotic patients but data are contrasting.In this review,we will try to answer these questions,providing a critical analysis of data reported in literature.

Fusing Fixed and Hint Landmarks on Crowd Paths for Automatically Constructing Wi-Fi Fingerprint Database

In typical Wi-Fi based indoor positioning systems employing fingerprint model,plentiful fingerprints need to be trained by trained experts or technician,which extends labor costs and restricts their promotion.In this paper,a novel approach based on crowd paths to solve this problem is presented,which collects and constructs automatically fingerprints database for anonymous buildings through common crowd customers.However,the accuracy degradation problem may be introduced as crowd customers are not professional trained and equipped.Therefore,we define two concepts:fixed landmark and hint landmark,to rectify the fingerprint database in the practical system,in which common corridor crossing points serve as fixed landmark and cross point among different crowd paths serve as hint landmark.Machinelearning techniques are utilized for short range approximation around fixed landmarks and fuzzy logic decision technology is applied for searching hint landmarks in crowd traces space.Besides,the particle filter algorithm is also introduced to smooth the sample points in crowd paths.We implemented the approach on off-the-shelf smartphones and evaluate the performance.Experimental results indicate that the approach can availably construct WiFi fingerprint database without reduce the localization accuracy.

Visual attention and clustering-based automatic selection of landmarks using single camera

An improved method with better selection capability using a single camera was presented in comparison with previous method. To improve performance, two methods were applied to landmark selection in an unfamiliar indoor environment. First, a modified visual attention method was proposed to automatically select a candidate region as a more useful landmark. In visual attention, candidate landmark regions were selected with different characteristics of ambient color and intensity in the image. Then, the more useful landmarks were selected by combining the candidate regions using clustering. As generally implemented, automatic landmark selection by vision-based simultaneous localization and mapping(SLAM) results in many useless landmarks, because the features of images are distinguished from the surrounding environment but detected repeatedly. These useless landmarks create a serious problem for the SLAM system because they complicate data association. To address this, a method was proposed in which the robot initially collected landmarks through automatic detection while traversing the entire area where the robot performed SLAM, and then, the robot selected only those landmarks that exhibited high rarity through clustering, which enhanced the system performance. Experimental results show that this method of automatic landmark selection results in selection of a high-rarity landmark. The average error of the performance of SLAM decreases 52% compared with conventional methods and the accuracy of data associations increases.

The Story Behind the Images:Photographer Li Shaobai and His “Invisible Series”

My camera lens is so illusionary that the authenticity of the Forbidden City is fading away. And my perspective is as narrow as an awl which slowly stings into the profundity of history... —Li

Advances in thin film lubrication(TFL): From discovery to the aroused further researches

Thin film lubrication(TFL) is known as a mode of fluid-film lubrication regime bridging the gap between elastohydrodynamic lubrication(EHL) and boundary lubrication(BL). Since the first recorded literature published in 1995, TFL has become one of the landmarks in the development of lubrication theory over the last twenty years. This article presents an overview of the advances in the research of TFL regime. We first begin with a brief introduction of the discovery of the phenomenon, followed by the discussion of the relevant essential aspects, such as the performing approach, theory and physical model. The state-of-the-art studies on both the theoretical and experimental fields are also presented, also latter with emphasis on the review of researches in several promising applications.