• Energy Research
• Closed Access close

Abstract This study extends an energy-balance-equation wave model (a phase-averaging wave model) for multidirectional random wave transformations to account for wave shoaling, refraction, diffraction, reflection and breaking. Quadratic upstream interpolation for convective kinematics is used in the discretization to reduce numerical diffusion. Predictions using the present wave model are compared with Sommerfeld's solutions for wave transformation through a gap between breakwaters, experimental observations for wave transformation due to a circular shoal, and field measurements for waves behind a breakwater. The results of these comparisons show fairly good agreement.

This study analyses and compares the cost efficiency of Japanese steam power generation companies using the fixed and random Bayesian frontier models. We show that it is essential to account for heterogeneity in modelling the performance of energy companies. Results from the model estimation also indicate that restricting CO2 emissions can lead to a decrease in total cost. The study finally discusses the efficiency variations between the energy companies under analysis, and elaborates on the managerial and policy implications of the results.

Abstract This paper presents a new approach to heat exchanger network (HEN) design making extensive use of randomization techniques. It is exceedingly simple to implement and gives new insight into the hardness and the cost landscape underlying a given problem. At the same time, the results from our algorithm may be used as good initial solutions required by most non-linear optimization problem formulations of HEN design. Practical networks involve trade-off between a number of factors, all of which are difficult to incorporate in a single design methodology. Our approach is blind to any design heuristic and generates a sufficiently large number of networks that can be further evaluated to pick up the most suitable network depending on specific design requirements. However, the current version of the algorithm is limited to HEN synthesis problems that can be solved without stream splitting. We have experimented with the three standard literature problems and obtained results that compare well with the previously published results, which justify further research in this direction.

Recently, morphological signs of damage were reported in rabbit Achilles tendon following extracorporeal shock wave application (ESWA) with an energy flux density (EFD) of 0.6 mJ/mm(2). However, it is unknown whether or not the same can be found after ESWA to other tendons such as the quadriceps tendon.We investigated the effects of ESWA in vivo on rabbit quadriceps tendon. Animals received 1,500 SW pulses each of different EFD ranging between 0.0 and 1.2 mJ/mm(2) on either the left or right quadriceps tendon. ESWA effects were investigated by histopathological examination.ESWA with EFD of 0.5 mJ/mm(2) upwards resulted in edema within the paratenon. ESWA with EFD of 1.2 mJ/mm(2) resulted in various morphological signs of damage within the tendon and paratenon.We conclude that ESWA to the quadriceps tendon in clinical experimental use should be restricted to EFD less than 0.5 mJ/mm(2).

This paper addresses the problem of overloading in power distribution networks, which stems from the transmission systems being incapable of delivering power from source to consumers during peak hours. This causes frequent power-outages (or blackouts), requiring the consumers to rely on alternative energy sources, e.g., Uninterrupted Power Supply (UPS) systems with batteries to meet their essential needs. This paper proposes a demand response (DR) framework to eliminate the problem of network overloading. The flexibility in the consumption of batteries and air conditioners (ACs) is exploited in the proposed framework. The operation of ACs is manipulated while maintaining occupant comfort, and the power flow from mains and batteries is scheduled based on an ensemble of demand forecast avoiding network overloading and consequent power-outages. The problem is modeled in an optimal control setting and solved using a stochastic model predictive control strategy, and a computationally effective method is also proposed to efficiently solve the underlying optimization problems. Towards the end, simulation results show the efficacy of the proposed framework to avoid overloading.

A fast MAP inference method for the general discrete labeling problems.A new graphical model that consists of four directed acyclic subgraphs (DAS).Message receiving inference based on four DAS structure.Four scanning method that utilizes message receiving inference.Extremely high speed and competitive accuracy compared to other MAP inference. We propose a message-receiving algorithm on a Directed Acyclic Subgraph (DAS) structure to approximate the solution of general labeling problems extremely quickly. The algorithm divides a graph into four subgraphs to get a joint distribution of all nodes, then passes messages in two fixed directions as inference on DASs. Message receiving is a modified version of message passing. When receiving messages on DAS structure, labeling results can be obtained after just four scans. The proposed algorithm was evaluated by using it to perform three labeling decision applications (binary segmentation, image denoising, and stereo matching). Compared to other highly-accurate iterative algorithms ( α -expansion, α - β swap, tree-reweighted message passing, sum-product belief propagation, max-product belief propagation, and FastPD), the proposed algorithm shows competitive accuracy but requires much less computational time. The proposed algorithm is appropriate for applications in which iterative schemes are undesirable, but which must get reliable labeling results within a limited time.

The study described here investigated the effects of extracorporeal shock wave therapy (ESWT) on functional recovery and neurotrophin-3 expression in the spinal cord after sciatic nerve injury in rats. Forty-five 8-wk-old rats were used and randomly divided into three groups: An experimental group, a control group and a sham group. The experimental group received ESWT after the nerve-crushing damage. The sciatic functional index and Dartfish Software were used to determine the effect of sciatic nerve damage on functional changes. A 1-cm length of spinal cord encompassing the L4-6 level was removed for Western blot analysis. The sciatic functional index significantly changed in both the ESWT and control groups after impairment. In the time course evaluation of the ankle angle in the toe off, the ESWT group had statistically significant increases from day 21 onward. There was a significant difference in neurotrophin-3 expression between the groups on days 1, 7 and 14 after impairment. Early application of ESWT increased the expression of neurotrophin-3 and neurotrophin-3 mRNA, and daily therapy facilitated the activity of macrophages and Schwann cells, which affect the survival and regeneration of neurons.

Interconnections problems in the megabit static random access memory (SRAM) chip are studied. A multilayer interconnect capacitance model is developed, and effects of interconnection on SRAM device performance parameters, such as propagation delay, speed, power consumption, and noise characteristics, are analyzed. A case study of 1-Mb SRAM chip interconnection is discussed. A multilayer interconnect approach is proposed to overcome on-chip interconnection difficulties. By implementing a double-layer interconnect approach, the wire length and chip size were reduced to 69\% and 58\%, respectively. Maximum access time of 30.8 ns with 1 W at 100 deg;C and wafer yield as high as 10\% was achieved