Monitoring trail: on fast link failure localization in all-optical WDM mesh networks

We consider an optical layer monitoring mechanism for fast link failure localization in all-optical wavelength-division-multiplexing (WDM) mesh networks. A novel framework of all-optical monitoring, called monitoring trail (m-trail), is introduced. It differs from the existing monitoring cycle (m-cycle) method by removing the cycle constraint. As a result, m-trail provides a general all-optical monitoring structure, which includes simple, nonsimple m-cycles, and open trails as special cases. Based on an in-depth theoretical analysis, we formulate an efficient integer linear program (ILP) for m-trail design to achieve unambiguous localization of each link failure. The objective is to minimize the monitoring cost (i.e., monitor cost plus bandwidth cost) of all m-trails in the solution. Numerical results show that the proposed m-trail scheme significantly outperforms its m-cycle-based counterpart.published_or_final_versio

Monitoring Cycle Design for Fast Link Failure Localization in All-Optical Networks

A monitoring cycle (m-cycle) is a preconfigured optical loop-back connection of supervisory wavelengths with a dedicated monitor. In an all-optical network (AON), if a link fails, the supervisory optical signals in a set of m-cycles covering this link will be disrupted. The link failure can be localized using the alarm code generated by the corresponding monitors. In this paper, we first formulate an optimal integer linear program (ILP) for m-cycle design. The objective is to minimize the monitoring cost which consists of the monitor cost and the bandwidth cost (i.e., supervisory wavelength-links). To reduce the ILP running time, a heuristic ILP is also formulated. To the best of our survey, this is the first effort in m-cycle design using ILP, and it leads to two contributions: 1) nonsimple m-cycles are considered; and 2) an efficient tradeoff is allowed between the monitor cost and the bandwidth cost. Numerical results show that our ILP-based approach outperforms the existing m-cycle design algorithms with a significant performance gain.published_or_final_versio

Commodity procurement risk management with futures contracts: a dynamic stack-and-roll approach

Procuring material from commodity spot markets can flexibly fulfil a forward production demand, but increase the risk of high procurement cost due to spot price volatility. In this paper, a dynamic stack-and-roll hedging approach using futures contracts is proposed. The approach aims at mitigating the procurement cost risk and optimising the terminal revenue received from the procurement and hedging activities. It separates the procurement planning horizon into multiple stages, along with varying hedging positions in the nearby futures contracts. Hedging positions are adjusted in response to commodity price behaviour and contemporary perceived information about forward production demand. Guided by the mean-variance criteria over the terminal revenue, dynamic programming is applied to derive a closed-form solution for optimal hedging positions in a discrete-time Markovian setting. Numerical experiments are carried out to assess the proposed approach with explicit solution in a realistic stochastic environment. The price processes are modelled by a fractal nonlinear regression model using real price data of China’s commodity market, while demand information process is modelled by Bayesian formula. The results show that the proposed approach outperforms naive hedging strategy, and effectively mitigates the procurement cost risk.postprin

Clinical management of a child with melanotic neuroectodermal tumour of infancy

A rare case of melanotic neuroectodermal tumour of infancy affecting the maxilla is reported. These are rare, mainly benign neoplasms that present during infancy. Prompt surgery and rehabilitation using partial dentures are essential to minimise the effects of the deformity. The integrated surgical and prosthodontic management needed to attain good restoration of aesthetic and masticatory function in a child are emphasised. Additional partial dentures need to be made that accommodate the changes in the dental arch that occur as the child grows.published_or_final_versio

Effect of temperature on moromi fermentation of soy sauce with intermittent aeration

Soy sauce has been widely used as one of the main seasoning agents in Asian countries. Soy sauce is produced by two-steps fermentation processes, namely koji fermentation and moromi fermentation. Inthis study, different temperatures (25, 35 and 45°C) for moromi fermentation in bioreactor were investigated for understanding their influences on soya sauce quality, in terms of pH variations, ethanolconcentrations and total nitrogen contents in raw soy sauce during moromi fermentation. It was learned that as the aging of moromi took place, the pH level was decreased from pH 7 to 4.88. Also, the soy sauce had lower concentration of ethanol when higher temperature was used in moromi fermentation but the difference of temperature did not show significantly effect on total nitrogen content in soy sauce. This study indicated that the temperature used in the moromi fermentation, coupled with intermittent aeration, imposed significant effects on soy sauce aging and quality. Higher fermentation temperature of 45°C enhanced the aging of soy sauce, accompanying with lower contents of ethanol and higher pH level in soy sauce. However, the total nitrogen content in the soy sauce was notsignificantly influenced by the fermentation temperature

Effects of stitching on delamination of satin weave carbon-epoxy laminates under mode I, mode II and mixed-mode I/II loadings

The objective of the present study is to characterize the effect of modified chain stitching on the delamination growth under mixed-mode I/II loading conditions. Delamination toughness under mode I is experimentally determined, for unstitched and stitched laminates, by using untabbed and tabbed double cantilever beam (TDCB) tests. The effect of the reinforcing tabs on mode I toughness is investigated. Stitching improves the energy release rate (ERR) up to 4 times in mode I. Mode II delamination toughness is evaluated in end-notched flexure (ENF) tests. Different geometries of stitched specimens are tested. Crack propagation occurs without any failure of stitching yarns. The final crack length attains the mid-span or it stops before and the specimen breaks in bending. The ERR is initially low and gradually increases with crack length to very high values. The mixedmode delamination behaviour is investigated using a mixed-mode bending (MMB) test. For unstitched specimens, a simple mixed-mode criterion is identified. For stitched specimens, stitching yarns do not break during 25% of mode I ratio tests and the ERR increase is relatively small compared to unstitched values. For 70% and 50% of mode I ratios, failures of yarns are observed during crack propagation and tests are able to capture correctly the effect of the stitching: it clearly improves the ERR for these two mixed modes, as much as threefold

The virtual organizing process—A critical tool for enterprise competitiveness in the information era

The term virtual enterprise has generated considerable confusion because of its rather liberal interpretation. This paper argues that the successful establishment of a virtual enterprise is mainly dependent on the virtual organizing processes of an enterprise\u27s strategies ( VOPES), rather than on the actual manifested transformation of the whole into a single virtual organization. A three-dimensional dynamic framework for VOPES is presented, with the aim of providing a coherent model for positioning the various virtual organizing strategies, and at the same time giving VOPES dynamic tendencies towards market negotiation, co-operation, co-ordination and collaboration. To achieve a competitive advantage, the top management of an enterprise operating in an intense information environment can organize their enterprise virtually by using the three-dimensional framework of: virtual customer relationship, virtual outsourcing, and virtual knowledge and expertise. The generic IT architecture of VOPES is also described and discussed

Sorafenib dose escalation is not uniformly associated with blood pressure elevations in normotensive patients with advanced malignancies.

Hypertension after treatment with vascular endothelial growth factor (VEGF) receptor inhibitors is associated with superior treatment outcomes for advanced cancer patients. To determine whether increased sorafenib doses cause incremental increases in blood pressure (BP), we measured 12-h ambulatory BP in 41 normotensive advanced solid tumor patients in a randomized dose-escalation study. After 7 days' treatment (400 mg b.i.d.), mean diastolic BP (DBP) increased in both study groups. After dose escalation, group A (400 mg t.i.d.) had marginally significant further increase in 12-h mean DBP (P = 0.053), but group B (600 mg b.i.d.) did not achieve statistically significant increases (P = 0.25). Within groups, individuals varied in BP response to sorafenib dose escalation, but these differences did not correlate with changes in steady-state plasma sorafenib concentrations. These findings in normotensive patients suggest BP is a complex pharmacodynamic biomarker of VEGF inhibition. Patients have intrinsic differences in sensitivity to sorafenib's BP-elevating effects

Correction: An intrinsically stretchable humidity sensor based on anti-drying, self-healing and transparent organohydrogels

Correction for ‘An intrinsically stretchable humidity sensor based on anti-drying, self-healing and transparent organohydrogels’ by Jin Wu et al., Mater. Horiz., 2019, 6, 595–603, DOI: 10.1039/C8MH01160E

The effects of antioxidants on pyridinoline cross linkage formation in human fibroblasts culture from hypertrophic scars

2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe