A cloud computing multi-objective task scheduling optimization based on fuzzy self-defense algorithm is proposed. Select the shortest time, the degree of resource load balance and the cost of ...multi-objective task completion as the goal of cloud computing multi-objective task scheduling, establish a mathematical model to measure the effect of multi-objective task scheduling, and construct the objective function of cloud computing multi-objective task scheduling. The experimental results show that the cloud computing multi-objective task scheduling optimization method based on fuzzy self-defense algorithm can improve the performance of multi-objective maximum completion time, deadline violation rate and virtual machine resource utilization.
A di(
o
-tolyl)borylgold complex was synthesized
via
the metathesis reaction of a gold alkoxide with tetra(
o
-tolyl)diborane(4). The resulting diarylborylgold complex exhibited a Lewis acidic boron ...center and a characteristic visible absorption that arises from its HOMO-LUMO excitation, which is narrower than that of a previously reported dioxyborylgold complex. The diarylborylgold complex reacted with isocyanide in a stepwise fashion to afford single- and double-insertion products and a C-C coupled product. Reactions of this diarylborylgold complex with C&z.dbd;O/N double bond species furnished addition products under concomitant formation of Au-C and B-O/N bonds, which suggests nucleophilic reactivity of the gold metal center. DFT calculations provided details of the underlying reaction mechanism, which involves an initial coordination of the C&z.dbd;O/N bond to the boron vacant p-orbital of the diarylboryl ligand followed by a migration of the gold atom from the tetracoordinate sp
3
-hybridized boron center, which is analogous to the reactivity of the conventional sp
3
-hybridized borate species. The DFT calculations also suggested a stepwise mechanism for the reaction of this diarylborylgold complex with isocyanide, which afforded three different reaction products depending on the applied reaction conditions.
A di(
o
-tolyl)borylgold complex added to C&z.dbd;O/N double bond to form Au-C and B-O/N bonds. DFT calculations revealed a two-step mechanism consisting of the coordination of O/N atom to B atom followed by nucleophilic migration of Au atom.
In networked cyber-physical systems, the inter-delivery time of data packets becomes an important quantity of interest. However, providing a guarantee that the inter-delivery times of the packets are ..."small enough" becomes a difficult task in such systems due to the unreliable communication medium and limited network resources. We design scheduling policies that meet the inter-delivery time requirements of multiple clients connected over wireless channels. We formulate the problem as an infinite-state risk-sensitive Markov decision process, where large exceedances of inter-delivery times for different clients over their design thresholds are severely penalized. We reduce the infinite-state problem to an equivalent finite-state problem and establish the existence of a stationary optimal policy and an algorithm for computing it in a finite number of steps. However, its computational complexity makes it intractable when the number of clients is of the order of 100 or so that is found in applications such as in-vehicle networks. To design computationally efficient optimal policies, we, therefore, develop a theory based on the high reliability asymptotic scenario, in which the channel reliability probabilities are close to one. We thereby obtain an algorithm of relatively low computational complexity for determining an asymptotically optimal policy. To address the remaining case when the channels are not relatively reliable, we design index-based policies for the risk sensitive case, which extends key ideas for index policies in risk-neutral multi-armed bandit problems. Simulation results are provided to show the effectiveness of our policies.
In vehicular cloud computing (VCC) systems, the computational resources of moving vehicles are exploited and managed by infrastructures, e.g., roadside units, to provide computational services. The ...offloading of computational tasks and collection of results rely on successful transmissions between vehicles and infrastructures during encounters. In this paper, we investigate how to provide timely computational services in VCC systems. In particular, we seek to minimize the deadline violation probability given a set of tasks to be executed in vehicular clouds. Due to the uncertainty of vehicle movements, the task replication methodology is leveraged which allows one task to be executed by several vehicles, and thus trading computational resources for delay reduction. The optimal task replication policy is of key interest. We first formulate the problem as a finite-horizon sampled-time Markov decision problem and obtain the optimal policy by value iterations. To conquer the complexity issue, we propose the balanced-task-assignment (BETA) policy which is proved optimal and has a clear structure: it always assigns the task with the minimum number of replicas. Moreover, a tight closed-form performance upper bound for the BETA policy is derived, which indicates that the deadline violation probability follows the Rayleigh distribution approximately. Applying the vehicle speed-density relationship in the traffic flow theory, we find that vehicle mobility benefits VCC systems more compared with road traffic systems, by showing that the optimum vehicle speed to minimize the deadline violation probability is larger than the critical vehicle speed in traffic theory which maximizes traffic flow efficiency.
Transition metal–boryl complexes play an important role as reactive intermediates in catalytic borylation processes and have enjoyed tremendous exploration. Over the years, it has been well ...established that a boryl ligand possesses strong nucleophilicity in copper(I)–boryl complexes. Thus, the role played by boron’s “empty” p orbital has often been overlooked and d-electrons’ effect from the metal is even more seldom mentioned, despite the fact that they in theory should also have influence on the reactivity of a metal–boryl complex. In this work, the reactivity of metal–boryl complexes has been systematically studied with the aid of density functional theory calculations. We have revealed that when the metal is more electronegative, the nucleophilic feature of boryl is diminished and will no longer be active, whereas when the boryl is not substituted with π-donating groups, the “empty” p orbital of boron will be active and can serve as the electrophilic site. In addition, when the metal center changes from relatively inert d10 to d8, the d electrons can also play the role of a nucleophile. With a much more comprehensive understanding of metal–boryl complexes, this work will benefit the future catalyst design related to transition-metal-catalyzed borylation reactions.
Freesia hybrida
is rich in flower colors with beautiful flower shapes and pleasant aroma. Flavonoids are vital to the color formation of its flowers. In this study, five
Freesia
cultivars with ...different flower colors were used to study on the level of accumulation of their flavonoids and expression of flavonoid-related genes and further explore new novel transcription factor (TF). Ultra-high-performance liquid chromatography and VION ion mobility quadrupole time-of-flight mass spectrometer (UPLC-Q-TOF-MS) were used to determine the flavonoids. Combined with transcriptome sequencing technology, the molecular mechanism of the flavonoid metabolism difference in
Freesia
was revealed. A total of 10 anthoxanthin components and 12 anthocyanin components were detected using UPLC-Q-TOF-MS. All six common anthocyanin aglycones in high plants, including cyanidin, delphinidin, petunidin, peonidin, malvidin, and pelargonidin, were detected in
Freesia
at first time in this study. In orange, yellow, and white cultivars, anthoxanthins gradually decreased with the opening of the petals, while in red and purple cultivars, anthoxanthins first increased and then decreased. No anthocyanin was detected in yellow and white cultivars, while anthocyanins increased with the opening of the petals and reached their maximum at the flowering stage (S3) in other three cultivars. The correlation analysis revealed that the color of
Freesia
petals was closely related to the composition and content of anthoxanthins and anthocyanins. Petals of five cultivars at S3 were then selected for transcriptome sequencing by using the Illumina Hiseq 4000 platform, and a total of 100,539 unigenes were obtained. There were totally 5,162 differentially expressed genes (DEGs) when the four colored cultivars were compared with the white cultivar at S3. Comparing all DEGs with gene ontology (GO), KEGG, and Pfam databases, it was found that the genes involved in the flavonoid biosynthesis pathway were significantly different. In addition, AP2, WRKY, and bHLH TF families ranked the top three among all differently expressed TFs in all DEGs. Quantitative real-time PCR (qRT-PCR) technology was used to analyze the expression patterns of the structural genes of flavonoid biosynthesis pathway in
Freesia
. The results showed that metabolic process was affected significantly by structural genes in this pathway, such as
CHS1
,
CHI2
,
DFR1
,
ANS1
,
3GT1
, and
FLS1
. Cluster analysis was performed by using all annotated WRKY and AP2 TFs and the above structural genes based on their relatively expression. Four novel candidate TFs of WRKY and AP2 family were screened. Their spatiotemporal expression patterns revealed that these four novel TFs may participate in the regulation of the flavonoid biosynthesis, thus controlling its color formation in
Freesia
petals.
Base station (BS) sleeping operation is one of the effective ways to save energy consumption of cellular networks, but it may lead to longer delay to the customers. The fundamental question then ...arises: How much energy can be traded off by a tolerable delay? In this paper, we characterize the fundamental tradeoffs between total energy consumption and overall delay in a BS with sleep mode operations by queueing models. Here, the BS total energy consumption includes not only the transmitting power but also basic power (for baseband processing, power amplifier, etc.) and switch-over power of the BS working mode, and the overall delay includes not only transmission delay but also queueing delay. Specifically, the BS is modeled as an M/G/1 vacation queue with setup and close-down times, where the BS enters sleep mode if no customers arrive during the close-down (hysteretic) time after the queue becomes empty. When asleep, the BS stays in sleep mode until the queue builds up to N customers during the sleep period ( N-Policy) . Several closed-form formulas are derived to demonstrate the tradeoffs between the energy consumption and the mean delay for different wake-up policies by changing the close-down time, setup time, and the parameter N. It is shown that the relationship between the energy consumption and the mean delay is linear in terms of mean close-down time, but non-linear in terms of N. The explicit relationship between total power consumption and average delay with varying service rate is also analyzed theoretically, indicating that sacrificing delay cannot always be traded off for energy saving. In other words, larger N may lead to lower energy consumption, but there exists an optimal N* that minimizes the mean delay and energy consumption at the same time. We also investigate the maximum delay (delay bound) for certain percentage of service and find that the delay bound is nearly linear in mean delay in the cases tested. Therefore, similar tradeoffs exist between energy consumption and the delay bound. In summary, the closed-form energy-delay tradeoffs cast light on designing BS sleeping and wake-up control policies that aim to save energy while maintaining acceptable quality of service.
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•A novel 3D vertical-flow paper-based device (3VPD) integrated with a sandwich-type fluorescent immunoassay is developed.•The 3VPD can be applied for multiplexed detection of cancer ...biomarkers simultaneously based on the principle of origami.•The proposed 3VPD shows high sensitivity and selectivity for detecting CEA, AFP and CA199 in human serum, respectively.
A novel three-dimensional (3D) vertical-flow paper-based device (3VPD), integrated with a sandwich-type fluorescent immunoassay, was developed for multiplexed detection of cancer biomarkers simultaneously based on the principle of origami. The developed 3VPD, composed of a sample layer, a splitting layer, and a test layer, could be fabricated simply by wax-printing on paper at a large scale. Herein, a vertical-flow immunoassay was introduced into the device, in which fluorescein isothiocyanate labeled antibodies were coated on the splitting layer and mouse monoclonal capture antibodies were functionalized on the test layer. The proposed 3VPD showed high sensitivity and selectivity for detecting three cancer biomarkers, carcinoembryonic antigen (CEA), a-fetoprotein (AFP), and cancer antigen 199 (CA199) with detection limits of 0.03 ng/mL, 0.05 ng/mL, and 0.09 U/mL in human serum, respectively. The results obtained in human serum were compatible with the reference values which were acquired from parallel single-analyte. The developed 3VPD provides a new strategy to develop an inexpensive and sensitive approach for simultaneous detection of multiple analytes and comprehensive clinical diagnosis by a single test.
Base station (BS) sleeping is an effective way to improve the energy-efficiency of cellular networks. However, it may bring extra user-perceived delay. We conduct a theoretical study into the impact ...of BS sleeping on both energy-efficiency and user-perceived delay. We consider hysteresis sleep and three typical wake-up schemes, namely single sleep, multiple sleep, and N-limited schemes. We model the system as an M/G/1 vacation queue, which captures the setup time, the mode-changing cost, as well as the counting or detection cost during the sleep mode. Closed-form expressions for the average power and the Laplace-Stieltjes transform of delay distribution are obtained. The impacts of system parameters on these expressions are analyzed. We then formulate an optimization problem to design delay-constrained energy-optimal BS sleeping policies. We show that the optimal solutions possess a special structure, thereby allowing us to obtain them explicitly or numerically by simple bisection search. In addition, the relationship between the optimal power consumption and the mean delay constraint is analyzed, so as to answer the fundamental question: how much energy can be saved by trading off a certain amount of delay? It is shown that this optimal relationship is linear only when the delay constraint is lower than a threshold. Numerical studies are also conducted, where the impact of detection or counting cost during the sleep mode is explored, and the delay distribution under the optimal policy is obtained.
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