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941.
Multiple Kernel Learning (MKL) is a popular generalization of kernel methods which allows the practitioner to optimize over convex combinations of kernels. We observe that many recent MKL solutions can be cast in the framework of oracle based optimization, and show that they vary in terms of query point generation. The popularity of such methods is because the oracle can fortuitously be implemented as a support vector machine. Motivated by the success of centering approaches in interior point methods, we propose a new approach to optimize the MKL objective based on the analytic center cutting plane method (accpm). Our experimental results show that accpm outperforms state of the art in terms of rate of convergence and robustness. Further analysis sheds some light as to why MKL may not always improve classification accuracy over naive solutions. 相似文献
942.
Shiu-Wan Hung Min-Jhih Cheng Pei-Che Chen 《International journal of human-computer interaction》2013,29(10):666-677
With the advancement of Internet technology, online shopping has emerged as a popular way of making purchases. However, because online shopping does not allow immediate enjoyment of purchases as bricks-and-mortar shops do, cultivating customers' trust in online businesses is especially important in attracting return customers. Previous studies have put forward the factors that build multidimensional trust but not systematically examined them. This article reexamines factors of building customer trust and makes a systematic study of the relationship between customers' perceived waiting and repurchase intention. This study examines online stores' professional ability, integrity, and benevolence were selected as the three constructing factors of trust. A total of 351 valid customer questionnaires were collected and analyzed using structural equation modeling. It was found that the most influential factor in customer trust was the security of the online business' information system, followed by the privacy protection, whereas the third-party guarantees and recommendation exhibited the third strongest correlation. Furthermore, the perceived waiting was a significant factor affecting customers' decision to return, notwithstanding their trust in an online business. 相似文献
943.
Wei-Tsong Wang Shih-Yu Cheng Lin-Yo Huang 《International journal of human-computer interaction》2013,29(3):139-155
Although there have been studies discussing the influence of technology-based services on the overall service efficiency and quality of organizations in various industries, very little effort has been devoted to investigating this issue in the healthcare industry. Hospital image is considered to be a crucial factor influencing patients' choice of hospitals, but few studies specifically examine its association with technology-based services. By consulting the model of the European Customer Satisfaction Index, a research model for evaluating the impact of the use of technology-based services on hospital image, patient satisfaction, and patient loyalty in the healthcare industry is developed and examined in this study using survey data collected from 738 patients at two medical centers with an online appointment system. The research results confirm the importance of providing quality, technology-based services in enhancing hospital image, patient satisfaction, and patient loyalty. The implications of this research and suggestions for future work are also discussed. 相似文献
944.
This study compared the mounting time and strain on the head‐neck while using an old model (forehead and cheek supported) and a new model (head harness supported) of head‐mounted night vision goggle systems in the postures of standing, sitting, and lying prone. The results showed that effectively reducing the mounting time was attributed to the ease and less time required for length adjustments of the head harness in the new model. The novel device received higher positive subjective ratings for convenience and comfort while wearing than did the old model. Although the weight of the new model was decreased to 0.794 kg and the length was reduced to 0.155 m, the loads on the head‐neck complex remained high. These findings suggest that a rifle should be fitted with the night vision goggle or handheld model to decrease neck‐shoulder workload if the prone position is the most frequent and important posture for soldiers. © 2011 Wiley Periodicals, Inc. 相似文献
945.
We consider a scheduling problem in which two agents, each with a set of non-preemptive jobs, compete to perform their jobs on a common bounded parallel-batching machine. Each of the agents wants to minimize an objective function that depends on the completion times of its own jobs. The goal is to schedule the jobs such that the overall schedule performs well with respect to the objective functions of both agents. We focus on minimizing the makespan or the total completion time of one agent, subject to an upper bound on the makespan of the other agent. We distinguish two categories of batch processing according to the compatibility of the agents. In the case where the agents are incompatible, their jobs cannot be processed in the same batch, whereas all the jobs can be processed in the same batch when the agents are compatible. We show that the makespan problem can be solved in polynomial time for the incompatible case and is NP-hard in the ordinary sense for the compatible case. Furthermore, we show that the latter admits a fully polynomial-time approximation scheme. We prove that the total completion time problem is NP-hard and is polynomially solvable for the incompatible case with a fixed number of job types. 相似文献
946.
This paper reports the investigation and analysis of the status and dynamic changes of ecological environment quality in the main stream of Songhua river basin. The evaluation index system was established and the eco-environment quality in the year of 2000 and 2008 was studied in depth. Based on our research, the trend of dynamic changes of the eco-environment quality and its origins have been further discussed: In the year of 2000, the range of evaluation index covered from 0.31 to 0.47. Harbin and Yichun was relatively better than the rest of study areas. In the year of 2008, except districts of Daqing and Qitaihe, the environmental quality of Songhua river basin has entirely improved, wherein the evaluation index of the eco-environment covered from 0.31 to 0.57. Particularly, the eco-environment quality of Hegang and Shuangyashan has obtained significant improvement, whereas the improvement of Jiamusi was not obvious. According to the evaluation results, the environmental quality in the study area has an upward trend with the average growth rate 0.13% per year. 相似文献
947.
948.
949.
建立曲线坐标系下的三维水流泥沙湍流运动模型模拟弯曲渠道内布置水生植被后的水流结构和河床变形分布,计算了试验室60o弯道内流经植被的水流流速平面结构和断面分布以及不同植被布置情况对水流泥沙运动和床面变形的影响。数值结果较好地再现了试验规律。计算结果表明在弯道内布置植被会改变水流流速分布情况:植被覆盖区域的水流流速降低、弯道内二次流减弱和泥沙运动减弱,而非植被覆盖区域的水流流速增大、断面二次流依然存在且泥沙运动加剧。通过比较两种水生植被布置条件下的床面变形情况,发现合理布置植被可以减缓凹岸的泥沙侵蚀,但也会加剧凸岸的泥沙淤积。 相似文献
950.