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How to reduce power consumption within individual data centers has attracted major research efforts in the past decade, as their energy bills have contributed significantly to the overall operating costs. In recent years, increasi...
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How to reduce power consumption within individual data centers has attracted major research efforts in the past decade, as their energy bills have contributed significantly to the overall operating costs. In recent years, increasing research efforts have also been devoted to the design of practical power-saving techniques in content delivery networks (CDNs), as they involve thousands of globally distributed data centers with content server clusters. In this paper, we present a comprehensive survey on existing research works aiming to save power in data centers and content delivery networks that share high degree of commonalities in different aspects. We firstly highlight the necessities of saving power in these two types of networks, followed by the identification of four major power-saving strategies that have been widely exploited in the literature. Furthermore, we present a high-level overview of the literature by categorizing existing approaches with respect to their scopes and research directions. These schemes are later analyzed with respect to their strategies, advantages and limitations. In the end, we summarize several key aspects that are considered to be crucial in effective power-saving schemes. We also highlight a number of our envisaged open research directions in the relevant areas that are of significance and hence require further elaborations.
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The crack growth behaviour of hybrid boron/glass/aluminium fibre metal laminates (FMLs) under constant-amplitude fatigue loading was investigated. The hybrid FMLs consist of Al 2024-T3 alloy as the metal layers and a mixture of bo...
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The crack growth behaviour of hybrid boron/glass/aluminium fibre metal laminates (FMLs) under constant-amplitude fatigue loading was investigated. The hybrid FMLs consist of Al 2024-T3 alloy as the metal layers and a mixture of boron fibres and glass fibres as the fibre layers. Two types of boron/glass/aluminium laminates were fabricated and tested. In the first type, the glass fibre/prepreg and the boron fibre/prepreg were used separately in the fibre layers, and in the second type, the boron fibres and the glass fibres were uniformly mingled together to form a hybrid boron fibre/glass fibre prepreg.
An analytical model was also proposed to predict the fatigue crack growth behaviour of hybrid boron/glass/aluminium FMLs. The effective stress intensity factor at a crack tip was formulated as a function of the remote stress intensity factor, crack opening stress intensity factor, and the bridging stress intensity factor. The bridging stress acting on the delamination boundary along the crack length was also calculated based on the crack opening relations. Then, the empirical Paris-type fatigue crack growth law was used for predicting the crack growth rates. A good correlation between the predicted and experimental crack growth rates has been obtained.
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In the two-step heating experiments, soymilk with 5% protein was first heated at 55, 60, 65, 70, 75 or 80C for Wmin, and then heated at 97C for another 10 min. As a control, the soymilk was heated at 97C for 10 to 60 min by contin...
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In the two-step heating experiments, soymilk with 5% protein was first heated at 55, 60, 65, 70, 75 or 80C for Wmin, and then heated at 97C for another 10 min. As a control, the soymilk was heated at 97C for 10 to 60 min by continuous one-step heating. The viscosity of the heated soymilk was measured after cooling to room temperature. Results showed that the two-step heating increased the soymilk viscosity by up to six times the viscosity of the control. The maximal viscosity was reached when the first-step heating temperature was 70C. Differential scanning calorimetry showed separate dena-turation of soy 7S and 11S proteins was related to the viscosity increase. Soymilk protein content and soybean variety also influenced the viscosity. Three heat transfer methods, including ohmic heating, steam injection and water bath heating, produced different viscosities of soymilk.
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These experiments were undertaken to assess the importance of cytoplasmic (c) sorbitol oxidation versus mitochondrial (m) pyruvate oxidation in mediating neural and vascular dysfunction attributable to hyperglycemia in diabetic ra...
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These experiments were undertaken to assess the importance of cytoplasmic (c) sorbitol oxidation versus mitochondrial (m) pyruvate oxidation in mediating neural and vascular dysfunction attributable to hyperglycemia in diabetic rats. Increased oxidation of sorbitol is coupled to enzymatic reduction of free oxidized NAD(+)c to reduced NADHc, manifested by an increased ratio of NADH to NAD(+)c. Likewise, increased oxidation of pyruvate is coupled to reduction of NAD(+)m to NADHm, which increases the NADH/NAD(+)m ratio. Specific inhibitors of sorbitol production or sorbitol oxidation normalized: increased diabetic nerve NADH/NAD(+)c, impaired nerve-conduction velocity, and vascular dysfunction in sciatic nerve, retina, and aorta; however, they had little or no impact on increased NADH/NAD(+)m. These observations provide, for the first time, strong in vivo evidence for the primacy of sorbitol oxidation versus. pyruvate oxidation in mediating the metabolic imbalances, impaired nerve conduction, and vascular dysfunction evoked by diabetes. These findings are consistent with (a) the fact that oxidation of sorbitol produces "prooxidant" NADHc uncoupled from subsequent production of "antioxidant" pyruvate required for reoxidation of NADHc to NAD(+)c by lactate dehydrogenase, and (b) the hypothesis that neural and vascular dysfunction in early diabetes are caused primarily by increased NADHc, which fuels superoxide production by NADH-driven oxidases.
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PURPOSE: The purpose of this study was to investigate how sustained convergence induces phoria adaptation and changes divergence dynamics. METHODS: Near dissociated phoria and divergence step responses were recorded using an infra...
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PURPOSE: The purpose of this study was to investigate how sustained convergence induces phoria adaptation and changes divergence dynamics. METHODS: Near dissociated phoria and divergence step responses were recorded using an infrared eye movement monitor on four binocularly normal subjects. We tested three different adapting vergence positions (16 degrees , 6 degrees , and 0.5 degrees ) and measured 4 degrees divergence step responses for two different initial vergence positions (16 degrees and 4.5 degrees ). Dynamics were quantified by measuring peak velocities of the divergence responses. RESULTS: Phoria was significantly adapted after subjects fixated on a sustained convergent target at near (16 degrees ) and at far (0.5 degrees ). As a result of sustained convergence, divergence peak velocity from a 4 degrees step stimulus significantly changed. A regression analysis showed that when the phoria became more esophoric (near adapted) the peak velocity for the divergence steps with an initial position of 16 degrees decreased (R=0.54, p=0.04). A trend was observed between the change vergence velocity and the change in phoria. Change was defined as the post-adapted data minus the pre-adapted data for vergence steps with an initial position of 16 degrees (R=0.65) and 4.5 degrees (R=0.66). Furthermore, the modification of divergence dynamics was dependent on the initial position of those divergence steps (initial position of 16 degrees versus 4.5 degrees ). CONCLUSION: As a result of sustained convergence, phoria and divergence dynamics changed in a correlated manner. Such correlated changes in phoria and divergence dynamics are not explained by current models of disparity vergence eye movements.
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The phylogenetic positions of the Bayanbulak sheep in China and the Sipsu sheep in Bhutan in the northern Asian sheep group were determined on the basis of allele frequency data for five informative and polymorphic loci of blood p...
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The phylogenetic positions of the Bayanbulak sheep in China and the Sipsu sheep in Bhutan in the northern Asian sheep group were determined on the basis of allele frequency data for five informative and polymorphic loci of blood protein and nonproteins, such as transferrin (TF), arylesterase (ES), hemoglobin-beta (HB-beta), X-protein (XP), and potassium transport (KE), using different electrophoretic and ion-densitometric techniques. Based on Nei's genetic distance, clustering analysis by the UPGMA method showed that the Bayanbulak sheep is clustered in the northern Asian sheep group. Furthermore, the Bayanbulak sheep belongs to a subgroup containing the Khalkhas and Hu sheep of the Mongolian sheep group, which is distinguished from another subgroup of the small-tailed Han, Tan, Tong, and Wadi sheep. The Bayanbulak sheep was closest to the Hu sheep, despite a morphological difference in the fat deposits. In addition to these findings, the Sipsu sheep was verified to belong to the Baruwal sheep.
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OBJECTIVE: The aim of this study was to evaluate the efficacy and tolerability of quetiapine and paroxetine monotherapy for major depression in bipolar disorder. METHOD: 740 patients (478 bipolar I, 262 bipolar II) with major depr...
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OBJECTIVE: The aim of this study was to evaluate the efficacy and tolerability of quetiapine and paroxetine monotherapy for major depression in bipolar disorder. METHOD: 740 patients (478 bipolar I, 262 bipolar II) with major depressive episodes (DSM-IV) were randomly assigned to quetiapine 300 mg/d (n = 245), quetiapine 600 mg/d (n = 247), paroxetine 20 mg/d (n = 122), or placebo (n = 126) for 8 weeks. The primary end point was the change from baseline in Montgomery-Asberg Depression Rating Scale (MADRS) total score. The study was conducted from May 2005 to May 2007. RESULTS: Mean MADRS score change from baseline at 8 weeks was -16.19 for quetiapine 300 mg, -16.31 for quetiapine 600 mg, -13.76 for paroxetine, and -12.60 for placebo (P < .001 for both quetiapine doses, P = .313 for paroxetine, vs placebo). Quetiapine-treated (both doses), but not paroxetine-treated, patients showed significantly greater improvements (P < or = .05) in most secondary outcomes measures at week 8 versus the placebo group. Paroxetine significantly improved Hamilton Anxiety Rating Scale scores versus placebo (P < .05) but not MADRS or Hamilton Depression Rating Scale (HDRS) scores. Both quetiapine doses were associated with greater improvements than paroxetine for MADRS and HDRS scores. The most common adverse events were dry mouth, somnolence, sedation, and dizziness with quetiapine (both doses) and dry mouth, sedation, headache, insomnia, and nausea with paroxetine. The incidence of treatment-emergent mania/hypomania was lower with quetiapine compared with paroxetine and placebo. CONCLUSIONS: Quetiapine (300 or 600 mg/d), but not paroxetine, was more effective than placebo for treating acute depressive episodes in bipolar I and II disorder. Quetiapine treatment was generally well tolerated. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00119652.
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Aerosol is frequently transported by a southward high-pressure system from the Asian Continent to Taiwan and had been recorded a 100% increase in mass level compared to non-event days from 2002 to 2005. During this time period, PM...
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Aerosol is frequently transported by a southward high-pressure system from the Asian Continent to Taiwan and had been recorded a 100% increase in mass level compared to non-event days from 2002 to 2005. During this time period, PM_(2.5) sulfate was found to increase as high as 155% on event days as compared to non-event days.
In this study, Asian emission estimations, Taiwan Emission Database System (TEDS), and meteorological simulation results from the fifth-generation Mesoscale Model (MM5) were used as inputs for the Community Multiscale Air Quality (CMAQ) model to simulate a long-range transport of PM_(2.5) event in a southward high-pressure system from the Asian Continent to Taiwan. The simulation on aerosol mass level and the associated aerosol components were found within a reasonable accuracy. During the transport process, the percentage of semi-volatile PM_(2.5) organic carbon in PM_(2.5) plume only slightly decreased from 22-24% in Shanghai to 21% near Taiwan. However, the percentage of PM_(2.5) nitrate in PM_(2.5) decreased from 16-25% to 1%. In contrast, the percentage of PM_(2.5) sulfate in PM_(2.5) increased from 16-19% to 35%. It is interesting to note that the percentage of PM_(2.5) ammonium and PM_(2.5) elemental carbon in PM_(2.5) remained nearly constant.
Simulation results revealed that transported pollutants dominate the air quality in Taipei when the southward high-pressure system moved to Taiwan. Such condition demonstrates the dynamic chemical transformation of pollutants during the transport process from continental origin over the sea area and to the downwind land.
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The interference coexistence performance between the systems of a Long Term Evolution (LTE) network and Mobile Satellite Service (MSS) system, both of which work around the frequency of approximately 2 GHz according to the bandwid...
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The interference coexistence performance between the systems of a Long Term Evolution (LTE) network and Mobile Satellite Service (MSS) system, both of which work around the frequency of approximately 2 GHz according to the bandwidth allocation in China, is proposed in this article. The related background of an MSS system and the common terminologies are introduced. Further, the coexistence scenarios of different coverage situations shared by the two systems are discussed. The interference impact of an MSS transmission on an LTE system is evaluated using a specific Monte Carlo method. Finally, simulation results show that although no crucial issues for the coexistence of an LTE downlink and the MSS are observed, the LTE uplink suffers a considerable amount of interference from the MSS transmission. Given the insufficient isolation between LTE and MSS existing networks, and the rapid advance in the field of LTE, problems may emerge in the near future. Further, this article can be of significance in providing reference for frequency spectrum planning in the existing LTE networks.
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The important field of research on ship operation is related to the high efficiency of transportation, the convenience of maneuvering ships, and the safety of navigation. This paper proposes an ontology-based fuzzy support agent f...
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The important field of research on ship operation is related to the high efficiency of transportation, the convenience of maneuvering ships, and the safety of navigation. This paper proposes an ontology-based fuzzy support agent for ship steering control and desires to testify the validity of the proposal by applying the fuzzy control model to the steering control system based on linguistic instruction. The fuzzy support agent is presented to build the maneuvering models of steersman and the miniature model for steering control system. The proposed fuzzy agent contains three main mechanisms, including the interpretation mechanism of linguistic instruction, the self-regulation mechanism, and the task performance mechanism. Furthermore, the task performance mechanism includes the kinematics module and the performance ontology. The simulation results show that the proposed approach can work effectively for ship steering control.
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