5,048 research outputs found
Meshless method with operator splitting technique for transient nonlinear bioheat transfer in two-dimensional skin tissues
A meshless numerical scheme combining the operator splitting method (OSM), the radial basis function (RBF) interpolation, and the method of fundamental solutions (MFS) is developed for solving transient nonlinear bioheat problems in two-dimensional (2D) skin tissues. In the numerical scheme, the nonlinearity caused by linear and exponential relationships of temperature-dependent blood perfusion rate (TDBPR) is taken into consideration. In the analysis, the OSM is used first to separate the Laplacian operator and the nonlinear source term, and then the second-order time-stepping schemes are employed for approximating two splitting operators to convert the original governing equation into a linear nonhomogeneous Helmholtz-type governing equation (NHGE) at each time step. Subsequently, the RBF interpolation and the MFS involving the fundamental solution of the Laplace equation are respectively employed to obtain approximated particular and homogeneous solutions of the nonhomogeneous Helmholtz-type governing equation. Finally, the full fields consisting of the particular and homogeneous solutions are enforced to fit the NHGE at interpolation points and the boundary conditions at boundary collocations for determining unknowns at each time step. The proposed method is verified by comparison of other methods. Furthermore, the sensitivity of the coefficients in the cases of a linear and an exponential relationship of TDBPR is investigated to reveal their bioheat effect on the skin tissue.The support for this research work by the Natural Science Foundation of China under the grant
11472099 and 11272230 is gratefully acknowledged
Stochastic regret minimization for revenue management problems with nonstationary demands
We study an admission control model in revenue management with nonstationary and correlated demands over a finite discrete time horizon. The arrival probabilities are updated by current available information, that is, past customer arrivals and some other exogenous information. We develop a regret‐based framework, which measures the difference in revenue between a clairvoyant optimal policy that has access to all realizations of randomness a priori and a given feasible policy which does not have access to this future information. This regret minimization framework better spells out the trade‐offs of each accept/reject decision. We proceed using the lens of approximation algorithms to devise a conceptually simple regret‐parity policy. We show the proposed policy achieves 2‐approximation of the optimal policy in terms of total regret for a two‐class problem, and then extend our results to a multiclass problem with a fairness constraint. Our goal in this article is to make progress toward understanding the marriage between stochastic regret minimization and approximation algorithms in the realm of revenue management and dynamic resource allocation. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 433–448, 2016Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135128/1/nav21704.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135128/2/nav21704_am.pd
Operative coordination in one case of Intracranial hematoma removal combined with resection of spleen surgery
Objective: the authors summarized the operative coordination means which operated on the the same patients with Intracranial hematoma removal combined with resection of spleen surgery at the same time. Methods: From the perspectives of preoperotive preparation, hand-washing nurses and visiting nurse respectively, the paper elaborated the placement of sterile towels, personnel reasonable stance, the check and management of sterile items, etc. Results:The surgery was finished smoothly. Conclusion:To assist the surgery is a comprehensive test for nurses’ ability at the operating room. The work responsibility should be clearly arranged, and the principle of intraoperative sterile operation should be strictly followed.目的 总结1例颅内血肿清除术和脾切除术这两种手术在同一患者、同一时间施行时的手术配合方法。方法 分别从术前准备、洗手护士、巡回护士工作等角度进行阐述了无菌巾的铺设、人员的合理站位、无菌物品的清点和管理等。结果 手术配合顺利完成。结论 配合该手术是对手术室护士能力的综合考验,必须做到正确、清楚划分各组的工作区域,遵循术中无菌操作原则
New Therapeutic Approaches for the Treatment of Rheumatoid Arthritis may Rise from the Cholinergic Anti-Inflammatory Pathway and Antinociceptive Pathway
Due to the complex etiology of rheumatoid arthritis (RA), it is difficult to be completely cured at the current stage although many approaches have been applied in clinics, especially the wide application of nonsteroidal anti-inflammatory drugs (NSAIDs) and disease-modifying antirheumatic drugs (DMARDs). New drug discovery and development via the recently discovered cholinergic anti-inflammatory and antinociceptive pathways should be promising. Based on the above, the nicotinic acetylcholine receptor agonists maintain the potential for the treatment of RA. Therefore, new therapeutic approaches may rise from these two newly discovered pathways. More preclinical experiments and clinical trials are required to confirm our viewpoint
A bearing fault detection method based on compressive measurements of vibration signal
The general method for bearing fault detection is achieved by using bearing vibration signals which sampled in the frame of Shannon sampling theory. So it is necessary to sample and save abundant original vibration data in the process of uninterrupted monitoring, and this will generate masses of original data which would burden the storage and transmission. For this issue, a fault detection method based on compressed sensing theory is proposed in this paper. It only needs to sample and save fewer compressive measurements of bearing vibration signal directly compared to original signal. There is no need to recover the original signal accurately for detecting bearing faults, while it just requires referring to the prior training result and reconstructing the overall energy distribution of the original signal in some transform domain. The availability and effectiveness of the method proposed is validated with bearing vibration signals sampled in practice
Bis(1,3,4-thiadiazol-2-yl) disulfide
The title compound, C4H2N4S4, lies about a twofold rotation axis situated at the mid-point of the central S—S bond. Each of two thiadiazole rings is essentially planar, with an rms deviation for the unique thiadiazole ring plane of 0.0019 (7) Å. C—H⋯N hydrogen bonds link adjacent molecules, forming zigzag chains along the c axis. In addition, these chains are connected by intermolecular S⋯S interactions [S⋯S = 3.5153 (11) Å] , forming corrugated sheets, and further fabricate a three-dimensional supramolecular structure by intermolecular N⋯S contacts [S⋯N = 3.1941 (17) Å]
- …