Another Perspective on Vocabulary Richness

This article examines the usefulness ofvocabulary richness for authorship attributionand tests the assumption that appropriatemeasures of vocabulary richness can capture anauthor's distinctive style or identity. Afterbriefly discussing perceived and actualvocabulary richness, I show that doubling andcombining texts affects some measures incomputationally predictable but conceptuallysurprising ways. I discuss some theoretical andempirical problems with some measures anddevelop simple methods to test how wellvocabulary richness distinguishes texts bydifferent authors. These methods show thatvocabulary richness is ineffective for largegroups of texts because of the extremevariability within and among them. I concludethat vocabulary richness is of marginal valuein stylistic and authorship studies because thebasic assumption that it constitutes awordprint for authors is false.     

缺血性糖尿病下肢病变的膝下动脉成形术

目的探讨膝下动脉的球囊成形术在治疗糖尿病缺血性下肢病变中的价值。方法对５３例糖尿病合并缺血性下肢病变患者６４侧缺血性下肢进行膝下动脉Deep球囊扩张成形术。对比患者手术前后临床症状的改变及足部溃疡的变化。结果５３例患者共１１９支动脉分支接受PTA治疗，５０例患者的１０１个分支成功地开通，技术成功率为８４．９％，所有５０例患者的临床症状均明显缓解，足部溃疡均变小，无需截肢。结论膝下动脉的球囊成形术是治疗缺血性糖尿病下肢病变安全有效的微创手段     

A 2.2 W, 80 MHz superscalar RISC microprocessor

A 28 mW/MHz at 80 MHz structured-custom RISC microprocessor design is described. This 32-b implementation of the PowerPC architecture is fabricated in a 3.3 V, 0.5 μm, 4-level metal CMOS technology, resulting in 1.6 million transistors in a 7.4 mm by 11.5 mm chip size. Dual 8-kilobyte instruction and data caches coupled to a high performance 32/64-b system bus and separate execution units (float, integer, loadstore, and system units) result in peak instruction rates of three instructions per clock cycle. Low-power design techniques are used throughout the entire design, including dynamically powered down execution units. Typical power dissipation is kept under 2.2 W at 80 MHz. Three distinct levels of software-programmable, static, low-power operation-for system power management are offered, resulting in standby power dissipation from 2 mW to 350 mW. CPU to bus clock ratios of 1×, 2×, 3×, and 4× are implemented to allow control of system power while maintaining processor performance. As a result, workstation level performance is packed into a low-power, low-cost design ideal for notebooks and desktop computers     

Plasma viral RNA load predicts disease progression in accelerated feline immunodeficiency virus infection

Viral RNA load has been shown to indicate disease stage and predict the rapidity of disease progression in human immunodeficiency virus type 1 (HIV-1)-infected individuals. We had previously demonstrated that feline immunodeficiency virus (FIV) RNA levels in plasma correlate with disease stage in infected cats. Here we expand upon those observations by demonstrating that plasma virus load is 1 to 2 logs higher in cats with rapidly progressive FIV disease than in long-term survivors. Differences in plasma FIV RNA levels are evident by 1 to 2 weeks after infection and are consistent throughout infection. We also evaluated humoral immune responses in FIV-infected cats for correlation with survival times. Total anti-FIV antibody titers did not differ between cats with rapidly progressive FIV disease and long-term survivors. These findings indicate that virus replication plays an important role in FIV disease progression, as it does in HIV-1 disease progression. The parallels in virus loads and disease progressions between HIV-1 and FIV support the idea that the accelerated disease model is well suited for the study of therapeutic agents directed at reducing lentiviral replication.     

Solar ultraviolet irradiation of human cornea, lens, and retina: equations of ocular irradiation

Photochemical damage of ocular tissues by solar radiation depends on the spectral composition of the radiation in the environment, the geometry of the coupling of that radiation to the eye, the spectral transmittances of the ocular components and any auxiliary lenses used, the spectral sensitivity of the irradiated tissue, the accumulated exposure dose, and the action of repair processes. This paper provides formulas for quantitative estimation of corneal, lenticular, and retinal UV irradiances from the sunlit environment under clear sky conditions. Applications of these formulas for ocular irradiation will be presented in subsequent papers for the cornea, lens, and retina, and the results will be evaluated using weighting functions for the sensitivity of ocular tissue.     

Ensemble-averaged Shack-Hartmann wave-front sensing for imaging through turbid media

A technique is described for ensemble-averaging the light wave emerging from a turbid medium, enabling the recovery of optical information that is otherwise lost in a speckle pattern. The technique recovers both an amplitude and a phase function for a wave that has been corrupted by severe scattering, without the use of holography. With the phase estimated, an ensemble-averaged field is constructed that can be backprojected to form an image of the object obscured by the scattering medium. Experimental results suggest that the technique can resolve two object points whose signals are unresolved on the exit surface of a diffuser.     

Computer vision in undergraduate education: modern embedded computing

Computer vision has historically been taught as a graduate subject since few examples of the discipline were being practiced in mainstream engineering. In recent years, the incorporation of multimedia into embedded devices has drawn some vision topics into mainstream attention. Examples of consumer products include digital video recorders, cellular phones, and automobile collision-avoidance systems. This paper describes the development of an undergraduate course that incorporates some vision topics into the larger context of embedded computing. Traditional topics, such as processor types, dynamic power management, and real-time scheduling, are taught alongside relevant vision topics, such as codecs, concurrent interfaces, and multimedia signal acquisition, storage, and rendering. In lab work, the students program hardware to operate as a digital video camera. While the primary goal for the course is to teach embedded computing, a secondary goal for the course is to entice students into graduate study in computer vision. However, a major developmental point was to justify the vision content in the context of how it serves the needs of students not opting for graduate study, as well as how the course would impact students working in other related graduate research areas.     

锁骨下动脉闭塞机械再通的方法研究

目的研究锁骨下动脉闭塞血管内机械再通方法和疗效。方法选择３２例症状性锁骨下动脉闭塞患者行血管内机械再通治疗，观察再通率及疗效。结果３２例锁骨下动脉闭塞患者中，用不同方法成功完成血管内机械再通后行血管内支架成形术，术后全部患者后循环缺血症状和上肢缺血症状明显改善。结论采用适当方法行机械再通治疗锁骨下动脉闭塞安全、可行。