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排序方式: 共有270条查询结果,搜索用时 15 毫秒
1.
This study describes a laboratory method for the estimation of emission from preservative-treated wood in the different situations where emissions could enter the environment for use classes 3 (not in contact with ground) and 4 and 5 (in contact with the ground, fresh water or sea water) according to OECD Guidelines. Samples of scotch pine sapwood (Pinus sylvestris L.) were treated with CCA (1% and 2%), ACQ-1900 (3% and 7%), ACQ-2200 (2%), Tanalith E 3491 (2% and 2.8%), and Wolmanit CX-8 (2%). 相似文献
2.
A Seven Y Erbil R Seven F Inci T Gülya?ar B Barut?u G Candan 《Canadian Metallurgical Quarterly》1998,16(4):333-345
The 'WHO Analgesic Ladder' is a well validated approach for the selection of appropriate analgesic therapy for cancer pain as well as pain in AIDS. The mainstay of analgesic intervention for cancer and AIDS pain of moderate to severe intensity continues to be the appropriate use of opioid analgesics. There is, however, a growing appreciation for the role of adjuvant analgesics, such as antidepressants and other psychotropic medications, at each step of the WHO Analgesic Ladder, particularly in the treatment of neuropathic pain. Knowledge of the indications and usefulness of psychotropic analgesic drugs in cancer and AIDS pain populations will be most important to clinicians practicing in psycho-oncology/AIDS settings, particularly since these drugs are useful not only in the treatment of psychiatric complications of cancer and AIDS, but also as adjuvant analgesic agents in the management of pain. This paper reviews the literature on the use of antidepressants, psychostimulants, neuroleptics, anticonvulsants and other psychotropic analgesics in the management of cancer and AIDS pain. Mechanisms of analgesia, drug selection, and recommendations for clinical usage are discussed. The appropriate and timely use of psychotropic adjuvant analgesic drugs represents an opportunity for active psychiatric contribution to the multidisciplinary management of cancer and AIDS pain. 相似文献
3.
Conventional constant false alarm rate (CFAR) methods use a fixed number of cells to estimate the background variance. For homogeneous environments, it is desirable to increase the number of cells, at the cost of increased computation and memory requirements, in order to improve the estimation performance. For nonhomogeneous environments, it is desirable to use less number of cells in order to reduce the number of false alarms around the clutter edges. In this work, we present a solution with two exponential smoothers (first order IIR filters) having different time-constants to leverage the conflicting requirements of homogeneous and nonhomogeneous environments. The system is designed to use the filter having the large time-constant in homogeneous environments and to promptly switch to the filter having the small time constant once a clutter edge is encountered. The main advantages of proposed Switching IIR CFAR method are computational simplicity, small memory requirement (in comparison to windowing based methods) and its good performance in homogeneous environments (due to the large time-constant smoother) and rapid adaptation to clutter edges (due to the small time-constant smoother). 相似文献
4.
Hua Song Lingzhi Zhang Rick B. Watson Drew Braden Umit S. Ozkan 《Catalysis Today》2007,129(3-4):346-354
The catalytic performance of cobalt catalysts supported on γ-Al2O3, TiO2, ZrO2 were studied for bio-ethanol steam reforming (BESR) reaction. The supported catalysts (10 wt%Co) were prepared by impregnation and characterized through Thermogravimetric analysis (TGA), H2 chemisorption, laser Raman Spectroscopy, Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), and temperature-programmed reaction (TPRxn). The metallic cobalt sites were found to correlate with the BESR reaction activity. The reaction and H2 chemisorption showed that ZrO2 supported catalyst showed the best dispersion and best catalytic activity. Over the 10% Co/ZrO2 catalyst, using a H2O:EtOH:inert molar ratio of 10:1:75 and a GHSV = 5000 h−1, 100% ethanol conversion and a yield of 5.5 mol H2/mol EtOH were obtained at 550 °C and atmospheric pressure. 相似文献
5.
Vydyanathan Naga Krishnamoorthy Sriram Sabin Gerald M. Catalyurek Umit V. Kurc Tahsin Sadayappan Ponnuswamy Saltz Joel H. 《Parallel and Distributed Systems, IEEE Transactions on》2009,20(8):1158-1172
Complex parallel applications can often be modeled as directed acyclic graphs of coarse-grained application tasks with dependences. These applications exhibit both task and data parallelism, and combining these two (also called mixed parallelism) has been shown to be an effective model for their execution. In this paper, we present an algorithm to compute the appropriate mix of task and data parallelism required to minimize the parallel completion time (makespan) of these applications. In other words, our algorithm determines the set of tasks that should be run concurrently and the number of processors to be allocated to each task. The processor allocation and scheduling decisions are made in an integrated manner and are based on several factors such as the structure of the task graph, the runtime estimates and scalability characteristics of the tasks, and the intertask data communication volumes. A locality-conscious scheduling strategy is used to improve intertask data reuse. Evaluation through simulations and actual executions of task graphs derived from real applications and synthetic graphs shows that our algorithm consistently generates schedules with a lower makespan as compared to Critical Path Reduction (CPR) and Critical Path and Allocation (CPA), two previously proposed scheduling algorithms. Our algorithm also produces schedules that have a lower makespan than pure task- and data-parallel schedules. For task graphs with known optimal schedules or lower bounds on the makespan, our algorithm generates schedules that are closer to the optima than other scheduling approaches. 相似文献
6.
7.
This research study analysed the interaction between people's postures and activities while in semi-public/leisure situations and during transportation (journey by train). In addition, the use of small electronic devices received particular emphasis. Video recordings in German trains and photographs in Dutch semi-public spaces were analysed using a variation of Branton and Grayson's (An evaluation of train seats by observation of sitting behaviour. Ergonomics, 10 (1), (1967), 35-51) postural targeting forms and photos. The analysis suggests a significant relationship between most activities and the position of the head, trunk and arms during transportation situations. The relationship during public situations is less straightforward. Watching, talking/discussing and reading were the most observed activities for the transportation and leisure situations combined. Surprisingly, differences in head, trunk, arm and leg postures were not significant when using small electronic devices. Important issues not considered in this study include the duration of the activities, the gender and age of observed subjects and the influence of the time of day. These are interesting issues to consider and include for future research. STATEMENT OF RELEVANCE: This study shows what activities people choose to carry out and their related postures when not forced to a specific task (e.g. driving). The results of this study can be used for designing comfortable seating in the transportation industry (car passenger, train, bus and aircraft seats) and semi-public/leisure spaces. 相似文献
8.
Naga Vydyanathan Umit Catalyurek Tahsin Kurc Ponnuswamy Sadayappan Joel Saltz 《Parallel Computing》2011,37(10-11):694-712
Scheduling, in many application domains, involves optimization of multiple performance metrics. For example, application workflows with real-time constraints have strict throughput requirements and also desire a low latency or response time. In this paper, we present a novel algorithm for the scheduling of workflows that act on a stream of input data. Our algorithm focuses on the two performance metrics, latency and throughput, and minimizes the latency of workflows while satisfying strict throughput requirements. We also describe steps to use the above approach to solve the problem of meeting latency requirements while maximizing throughput. We leverage pipelined, task and data parallelism in a coordinated manner to meet these objectives and investigate the benefit of task duplication in alleviating communication overheads in the pipelined schedule for different workflow characteristics. The proposed algorithm is designed for a realistic bounded multi-port communication model, where each processor can simultaneously communicate with at most k distinct processors. Experimental evaluation using synthetic benchmarks as well as those derived from real applications shows that our algorithm consistently produces lower latency schedules that meet throughput requirements, even when previously proposed schemes fail. 相似文献
9.
Lina Peng K. Selçuk Candan Christopher Mayer Karamvir S. Chatha Kyung Dong Ryu 《Multimedia Tools and Applications》2007,33(3):245-272
In this paper, we present the ARIA media processing workflow architecture that processes, filters, and fuses sensory inputs
and actuates responses in real-time. The components of the architecture are programmable and adaptable; i.e. the delay, size,
and quality/precision characteristics of the individual operators can be controlled via a number of parameters. Each data
object processed by qStream components is subject to transformations based on the parameter values. For instance, the quality of an output data object
and the corresponding processing delay and resource usage depend on the values assigned to parameters of the operators in
the object flow path. In Candan, Peng, Ryu, Chatha, Mayer (Efficient stream routing in quality- and resource-adaptive flow
architectures. In: Workshop on multimedia information systems, 2004), we introduced a class of flow optimization problems that promote creation and delivery of small delay or small resource-usage objects to the actuators in single-sensor, single-actuator
workflows. In this paper, we extend our attention to multi-sensor media processing workflow scenarios. The algorithms we present
take into account the implicit dependencies between various system parameters, such as resource consumption and object sizes.
We experimentally show the effectiveness and efficiency of the algorithms.
相似文献
Kyung Dong RyuEmail: |
10.
On Similarity Measures for Multimedia Database Applications 总被引:1,自引:1,他引:0
A multimedia database query consists of a set of fuzzy and boolean (or crisp) predicates, constants, variables, and conjunction,
disjunction, and negation operators. The fuzzy predicates are evaluated based on different media criteria, such as color,
shape, layout, keyword. Since media-based evaluation yields similarity values, results to such a query is defined as an ordered
set. Since many multimedia applications require partial matches, query results also include tuples which do not satisfy all
predicates. Hence, any fuzzy semantics which extends the boolean semantics of conjunction in a straight forward manner may
not be desirable for multimedia databases. In this paper, we focus on the problem of ‘given a multimedia query which consists of multiple fuzzy and crisp predicates, how to provide the user with a meaningful
overall ranking.’ More specifically, we study the problem of merging similarity values in queries with multiple fuzzy predicates. We describe
the essential multimedia retrieval semantics, compare these with the known approaches, and propose a semantics which captures
the retrieval requirements in multimedia databases.
Received 13 August 1999 / Revised 13 May 2000 / Accepted in revised form 26 July 2000 相似文献