首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   22篇
  免费   0篇
电工技术   5篇
化学工业   1篇
机械仪表   1篇
建筑科学   1篇
能源动力   1篇
轻工业   1篇
一般工业技术   1篇
冶金工业   7篇
原子能技术   1篇
自动化技术   3篇
  2012年   1篇
  2011年   4篇
  2010年   1篇
  2009年   3篇
  2007年   1篇
  2004年   1篇
  2000年   1篇
  1998年   2篇
  1997年   2篇
  1996年   2篇
  1991年   1篇
  1990年   1篇
  1983年   1篇
  1961年   1篇
排序方式: 共有22条查询结果,搜索用时 140 毫秒
1.
This paper presents an implementation of the watermarking method proposed by Venkatesan et al. in their paper [R. Venkatesan, V. Vazirani, S. Sinha, A graph theoretic approach to software watermarking, in: Fourth International Information Hiding Workshop, Pittsburgh, PA, 2001]. An executable program is marked by the addition of code for which the topology of the control-flow graph encodes a watermark. We discuss issues that were identified during construction of an actual implementation that operates on Java bytecode. We present two algorithms for splitting a watermark number into a redundant set of pieces and an algorithm for turning a watermark number into a control-flow graph. We measure the size and time overhead of watermarking, and evaluate the algorithm against a variety of attacks.  相似文献   
2.
3.
This is the first report of bioreactive self-assembled monolayers, covalently bound to atomically flat silicon surfaces and capable of binding biomolecules for investigation by scanning probe microscopy and other surface-related assays and sensing devices. These monolayers are stable under a wide range of conditions and allow tailor-made functionalization for many purposes. We describe the substrate preparation and present an STM and SFM characterization, partly performed with multiwalled carbon nanotubes as tapping-mode supertips. Furthermore, we present two strategies of introducing in situ reactive headgroup functionalities. One method entails a free radical chlorosulfonation process with subsequent sulfonamide formation. A second method employs singlet carbenemediated hydrogen-carbon insertion of a heterobifunctional, amino-reactive trifluoromethyl-diazirinyl crosslinker. We believe that this new substrate is advantageous to others, because it (i) is atomically flat over large areas and can be prepared in a few hours with standard equipment, (ii) is stable under most conditions, (iii) can be modified to adjust a certain degree of reactivity and hydrophobicity, which allows physical adsorption or covalent crosslinking of the biological specimen, (iv) builds the bridge between semiconductor microfabrication and organic/biological molecular systems, and (v) is accessible to nanopatterning and applications requiring conductive substrates.  相似文献   
4.
This paper describes the Electric Power Research Institute's (EPRI) current on-site large-scale soil-structure interaction (SSI) research. The objectives of the research are: (1) to obtain an earthquake database which can be used to substantiate SSI models and analysis methods; (2) to develop realistic SSI analysis guidelines and procedures based on experimental-analytical correlation; and (3) to quantify nuclear power plant reactor containment and internal component's seismic margin based on earthquake experience data.To meet the objectives, two model structures were sited in a high seismic region, Lotung, Taiwan, under the joint sponsorship of EPRI and the Taiwan Power Company (Taipower). The model structures which simulate scaled-down nuclear containments ( ) were constructed and instrumented within an existing strong motion array (SMART-1) deployed by U.C. Berkeley under a U.S. National Science Foundation grant. The instrumentation layout associated with the model structures included accelerometers on the models, on the internal components, on the ground surface, and in the ground. These instrumentations are to provide information required for validation and qualification of SSI models. Between September 1985 and November 1986, 18 earthquakes ranging from Richter magnitude 4.5 to 7.0 were recorded.The analysis phase of the research was conducted with the cooperation of the U.S. Nuclear Regulatory Commission (NRC) and Taipower. A round-robin approach was utilized with emphasis on blind predictions and independent assessment of existing methodologies. A total of 13 research teams from the United States, the Republic of China, Japan, and Switzerland participated in the effort. A workshop was held in December 1987 where research results and findings were presented. Further effort is ongoing to synthesize the results and findings for providing technical bases of developing improved SSI analyses guidelines and procedures.  相似文献   
5.
Even though interpersonal functioning is of great clinical importance for patients with borderline personality disorder (BPD), the comparative validity of different assessment methods for interpersonal dysfunction has not yet been tested. This study examined multiple methods of assessing interpersonal functioning, including self- and other-reports, clinical ratings, electronic diaries, and social cognitions in three groups of psychiatric patients (N = 138): patients with (1) BPD, (2) another personality disorder, and (3) Axis I psychopathology only. Using dominance analysis, we examined the predictive validity of each method in detecting changes in symptom distress and social functioning 6 months later. Across multiple methods, the BPD group often reported higher interpersonal dysfunction scores compared with other groups. Predictive validity results demonstrated that self-report and electronic diary ratings were the most important predictors of distress and social functioning. Our findings suggest that self-report scores and electronic diary ratings have high clinical utility, because these methods appear most sensitive to change. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
6.
Most hand prostheses do not provide intentional haptic feedback about movement performance; thus users must rely almost completely on visual feedback. This paper focuses on understanding the effects of learning and different stimulation sites when vibrotactile stimulation is used as the intentional haptic feedback. Eighteen unimpaired individuals participated in this study with a robotic interface to manipulate a virtual object with visual and vibrotactile feedback at four body sites (finger, arm, neck, and foot) presented in a random order. All participants showed improvements in object manipulation performance with the addition of vibrotactile feedback. Specifically, performance showed a strong learning effect across time, with learning transferring across different sites of vibrotactile stimulation. The effects of learning over the experiment overshadowed the effects of different stimulation sites. The addition of a cognitive task slowed participants and increased the subjective difficulty. User preference ratings showed no difference in their preference among vibrotactile stimulation sites. These findings indicate that the stimulation site may not be as critical as ensuring adequate training with vibrotactile feedback during object manipulation. Future research to identify improvements in vibrotactile-based feedback parameters with amputees is warranted.  相似文献   
7.
Intermuscular coherence can identify oscillatory coupling between two electromyographic (EMG) signals, measuring common presynaptic drive to motor neurons. Beta band oscillations (15-30 Hz) are hypothesized to originate largely from primary motor cortex, and are reduced during dynamic relative to static motor tasks. It has yet to be established whether motor imagery modulates beta intermuscular coherence. Using visual feedback, 10 unimpaired participants completed eighteen trials of pinching their right thumb and index finger at a constant force. During the 60-second trials, participants simultaneously engaged in one of three types of kinesthetic imagery: the right thumb and index finger executing a constant force pinch (static), the fingers of the right hand sequentially flexing and extending (dynamic), and the right foot pushing down with constant force (foot). Motor imagery of a dynamic motor task resulted in significantly lower intermuscular beta coherence than imagery of a static motor pinch task, without any difference in task performance or root-mean-square EMG. Thus, motor imagery affects intermuscular coherence in the beta band, even while measures of task performance remain constant. This finding provides insight for incorporation of beta band intermuscular coherence in future motor rehabilitation schemes and brain computer interface design.  相似文献   
8.
Incorporating sensory feedback with prosthetic devices is now possible, but the optimal methods of providing such feedback are still unknown. The relative utility of amplitude and pulse train frequency modulated stimulation paradigms for providing vibrotactile feedback for object manipulation was assessed in 10 participants. The two approaches were studied during virtual object manipulation using a robotic interface as a function of presentation order and a simultaneous cognitive load. Despite the potential pragmatic benefits associated with pulse train frequency modulated vibrotactile stimulation, comparison of the approach with amplitude modulation indicates that amplitude modulation vibrotactile stimulation provides superior feedback for object manipulation.  相似文献   
9.
The electrolarynx (EL) is a common rehabilitative speech aid for individuals who have undergone total laryngectomy, but they typically lack pitch control and require the exclusive use of one hand. The viability of using neck and face surface electromyography (sEMG) to control the onset, offset, and pitch of an EMG-controlled EL (EMG-EL) was studied. Eight individuals who had undergone total laryngectomy produced serial and running speech using a typical handheld EL and the EMG-EL while attending to real-time visual sEMG biofeedback. Running speech tokens produced with the EMG-EL were examined for naturalness by 10 listeners relative to those produced with a typical EL using a visual analog scale. Serial speech performance was assessed as the percentage of words that were fully voiced and pauses that were successfully produced. Results of the visual analog scale assessment indicated that individuals were able to use the EMG-EL without training to produce running speech perceived as natural as that produced with a typical handheld EL. All participants were able to produce running and serial speech with the EMG-EL controlled by sEMG from multiple recording locations, with the superior ventral neck or submental surface locations providing at least one of the two best control locations.  相似文献   
10.
Integrins as receptors for laminins   总被引:6,自引:0,他引:6  
Laminins are a family of trimeric glycoproteins present in the extracellular matrix and the major constituents of basement membranes. Integrins are alpha beta transmembrane receptors that play critical roles in both cell-matrix and cell-cell adhesion. Several members of the integrin family, including alpha 1 beta 1, alpha 2 beta 1, alpha 3 beta 1, alpha 6 beta 1, alpha 7 beta 1 and alpha 6 beta 4 heterodimers serve as laminin receptors on a variety of cell types. This review summarizes recent advances in understanding the involvement of individual integrins in cell interactions with laminins and the roles of laminin-binding integrins in adhesion-mediated events in vertebrates, including embryonic development, cell migration and tumor cell invasiveness, cell proliferation and differentiation, as well as basement membrane assembly. We discuss the regulation of integrin function via alternative splicing of cytoplasmic domains of alpha and beta subunits of the integrin receptors for laminins and present examples of functional collaboration between laminin-binding integrins and non-integrin laminin receptors. Advances in our understanding of the laminin-binding integrins continue to demonstrate the essential roles these receptors play in maintaining cell polarity and tissue architecture.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号