Fast indexing strategies for robust image hashes

Similarity preserving hashing can aid forensic investigations by providing means to recognize known content and modified versions of known content. However, this raises the need for efficient indexing strategies which support the similarity search. We present and evaluate two indexing strategies for robust image hashes created by the ForBild tool. These strategies are based on generic indexing approaches for Hamming spaces, i.e. spaces of bit vectors equipped with the Hamming distance. Our first strategy uses a vantage point tree, and the second strategy uses locality-sensitive hashing (LSH). Although the calculation of Hamming distances is inexpensive and hence challenging for indexing strategies, we improve the speed for identifying similar items by a factor of about 30 with the tree-based index, and a factor of more than 100 with the LSH index. While the tree-based index retrieves all approximate matches, the speed of LSH is paid with a small rate of false negatives.     

通督调神针法联合经筋结点放血治疗脑卒中后痉挛性瘫痪30例

目的 观察通督调神针法联合经筋结点放血治疗脑卒中后痉挛性瘫痪的临床疗效.方法 将60例脑卒中后痉挛性瘫痪的患者随机分为治疗组和对照组,各30例.对照组予以通督调神针法治疗,治疗组在通督调神针法的基础上予以经筋结点放血治疗.治疗前后分别采用美国国立卫生研究院卒中量表(National Institution Health...     

The effects of four different solvent vapours on the restoration of obliterated stamp markings from five different wooden surfaces

The stamp markings on wooden surfaces, which are placed on trees and products including antiques, indicate the status of trees and involve identifying data regarding the products. Such markings are obliterated either to facilitate illegal logging or to conceal product information. Despite the wide literature on the restoration of obliterated characters on metal and polymer surfaces, the recovery of defaced characters on wooden surfaces appears to be understudied. Several reference texts in the forensic marks’ examination literature suggest that water, water vapor, and alkaline solutions are useful in restoring the abraded markings on the wood. Since there does not seem to be any experimental study proving such success, this study aimed to fill this gap. This study conducted experimental research by using water, ethanol, ammonia, and chloroform to recover the scraped characters on samples obtained from walnut, beech, spruce, oak, and cedar trees. The cold-stamped characters, which were defaced at varying depths, were restored using vapor and liquid phases of four solvents. While the vapor phases of water, ethanol, and ammonia yielded good outcomes on all types of wooden surfaces, the liquid phases did not seem to be useful in the revisualization process. The response of the vapors, which varied between 62 and 220 s, depended on the type of wood. The restoration technique developed in this research offers the possibility of on-site usage, easy application, utilization of low-cost solvents, rapid recovery, and effectiveness on various wooden surfaces. Overall, the restoration methodology used in this research appears to be fruitful in retrieving identifying information on wooden samples.     

毫米波照射肾俞穴对家兔肾血流量的影响

In this Paper, the low Power milimeter wave ( MMW ) was employed to irradiate the rabbit on "Shenshu" point and on the surface of kidney, and the renal blood flow ( RBF ) before and after irradiation were measured by means of hydragon gas clearance method. The results show that RBF of both normal rabbit and that with acute renal blood deficiency are significantly increased after irradiating "Shenshu" Point (P<0.05); and compared with the rabbit whose kidney surface was irradiated, the RBF before and after irradiation have no significant difference (P>0.05); and that the RBF is increased more in the rabbit whose renal nerve was excised than in rabbit whose renal nerve was intact; there is a significant difference between them (P<0.05). The results of this paper suggest the effect of MMW irradiating "Shenshu" Point be similar to that of MMW irradiating the kidney surface, and as a new invulnarable specific therapy on points, MMW have a latent value in clinics.