Online Makespan Minimization: Beat LPT by Dynamic Locking

Online makespan minimization is a classic model in the field of scheduling. In this paper, we consider the over-time version, where each job is associated with a release time and a processing time. We only know a job after its release time and should schedule it on one machine afterward. The Longest Processing Time First (LPT) algorithm, as proven by Chen and Vestjens in 1997, achieves a competitive ratio of 1.5. However, for the case of two machines, Noga and Seiden introduced the SLEEPY algorithm, which achieves a competitive ratio of 1.382. Unfortunately, for the case of $m\geq 3$, there has been no convincing result that surpasses the performance of LPT. we propose a natural generalization that involves locking all the other machines for a certain period after starting a job, thereby preventing them from initiating new jobs. We show this simple approach can beat the $1.5$ barrier and achieve $1.482$-competitive when $m=3$. However, when $m$ becomes large, we observe that this simple generalization fails to beat $1.5$. Meanwhile, we introduce a novel technique called dynamic locking to overcome the new challenge. As a result, we achieve a competitive ratio of $1.5-\frac{1}{O(m^2)}$, which beats the LPT algorithm ($1.5$-comeptitive) for every constant $m$

Effect of Ni

With the development of high voltage transmission, there is an urgent need to develop ZnO varistor ceramics with high anti-aging properties. The key is to manipulate the intrinsic defect concentration of ZnO varistor ceramics precisely. In this paper, ZnO varistor ceramics doped with different contents of Ni2O3 are taken to study the relationship between the microstructure and electrical properties, and the effect of ZnO varistor ceramics doped with different contents on intrinsic defect concentration is also considered. The results show that, best electrical performance is shown when the content of Ni2O3 is 1.2mol%, the electrical breakdown field E1mA is 356 V/mm, the nonlinear coefficient reaches 32, and the leakage current IL is 3.4 . While the amount of the doped Ni2O3 is more 0.8mol%, a new phase of Co2Cr5Sb5O4 phase is observed from X-ray diffraction. The SEM micrographs showed that the average grain size decreased monotonously from 14.56 m to 5.73 m with the amount of the doped Ni2O3 increased. According to the results of dielectric spectroscopy, the intrinsic defect concentration increased with the contents of the doped Ni2O3 increased. The increase of Zinc interstitial is much greater than that of Oxygen vacancies, which is harmful to Long-term aging characteristics of ZnO varistor ceramics

Effects of wave forces on sediment transport patterns in micro-tidal estuaries

Estuarinesediment transport isdrivenbythecombinedactionof amultitudeof influencing factors, includingastronomical tides,waves dynamics, andriverdischarges.This study focusesontheeffectsofwave forcesonsediment transportpatterns inmicro-tidal estuaries nearWanbaoBeach,China.Numerical simulationsarecarriedoutusingDelft3D.Modelingscenariosareconfiguredusingdifferentwave characteristics, spanning fromtypicalwaves tothosewithareturnperiodof 50years.Results showthatwaveshaveapositiveeffecton landwardsediment transport, resultinga largeractiverangeof sediment.Bycomparing thespatial geomorphicvariationsundervarying waveconditions,wefindthatmodifications insignificantwaveheight (Hs)primarilyimpact thepositionoferosionanddepositionzones, whereasalterations inspectralpeakperiod(Tp)predominantly influence themagnitudeof thesechanges.The finding is furtherdemonstratedbyacomparisonof residual currentsunderdifferentwave intensities.Analysisof sediment transport rates indifferent transects indicates that thesediment transport rateishighestat themouthtransectsandlowestat thealongshoretransects.Moreover,variations in sediment transport rates exhibitdistinctivepatternsbetweenthe twooutlet transects, evenwhensubjectedto identicalwaveconditions. Thedisparitiesareattributedtodifferences inrunoffandthetopographical features inproximitytotheestuaries.Additionally,wefindthe sediment transportratebecomes insensitivetothevariations inHswhenHs is largerthanathresholdvalue.Thethresholddecreaseswith increasingTp

A Systematic Study on Berthing Capacity Assessment of Sanya Yazhou Fishing Port by Typhoon Prediction Model

This paper sheds light on the effect of combination modes on the evaluation of berthing capacity for Sanya Yazhou Fishing Port (SYFP) under hypothetical typhoon conditions. By statistically analysing the maximum probability of moving speeds and directions of historical typhoons passing through the fishing port, the representative typhoon path was determined with the nonparametric regression method. The designed typhoon wind fields of levels 12–17 were generated based on Holland’s parametric wind model. Then, the MIKE 21 BW model was used to obtain the high-precision wave distribution in the fishing port. The boundary conditions (significant wave height and peak period) of the MIKE 21 BW model were calculated by combining the MIKE 21 SW model with the designed typhoon wind fields. In SYFP, ships usually adopt the modes of multi-ship side-by-side and single anchor mooring during typhoons. In fair weather, approximately 158 vessels can be berthed if they are all large ones, while approximately 735 vessels can be moored if they are all small ones. However, with an increase in typhoon levels, the anchoring area for small vessels decreases. From the perspective of wave distribution in the fishing port, the number of large vessels moored was hardly affected by typhoons. This can be attributed to the breakwater, which significantly decreases the large wave height in the fishing port. Finally, a study on the framework of a method for hazard assessment of berthing capacity in the coming typhoon-driven storm waves was set up

Nanoparticle stripe sensor for highly sensitive and selective detection of mercury ions

Mercury and its compounds are emitted during industrial processes and are extremely harmful for eco systems and human health. Therefore, the detection of mercury ions (Hg2+) in our living and working environment is of great importance for the society and especially for the health of human beings. Here we demonstrate a proof of concept nanoparticle stripe sensor for highly sensitive and selective detection of Hg2+. This sensor is based on the changes of the charge transport between the neighboring nanoparticles in the nanoparticle stripe. The addition of Hg2+ induces a chelation between Hg2+ and carboxylic groups on the surface modification molecules and thus facilitates the charge transport, causing an increase of conductivity in the nanoparticle stripe. These nanoparticle stripes with a few layers in height and several micrometers in width possess large surface area, which increases their exposure to ions and improves the ability to detect Hg2+ at low concentrations. Besides, we studied the effect of molecular length on the sensitivity of the sensor. It is shown that the length of surface modification molecules is positively correlated with the sensitivity of the sensor. The fabricated devices exhibit a detection limit as low as 0.1 nM and a specific response towards Hg2+ ions

A Systematic Study on Berthing Capacity Assessment of Sanya Yazhou Fishing Port by Typhoon Prediction Model

This paper sheds light on the effect of combination modes on the evaluation of berthing capacity for Sanya Yazhou Fishing Port (SYFP) under hypothetical typhoon conditions. By statistically analysing the maximum probability of moving speeds and directions of historical typhoons passing through the fishing port, the representative typhoon path was determined with the nonparametric regression method. The designed typhoon wind fields of levels 12–17 were generated based on Holland’s parametric wind model. Then, the MIKE 21 BW model was used to obtain the high-precision wave distribution in the fishing port. The boundary conditions (significant wave height and peak period) of the MIKE 21 BW model were calculated by combining the MIKE 21 SW model with the designed typhoon wind fields. In SYFP, ships usually adopt the modes of multi-ship side-by-side and single anchor mooring during typhoons. In fair weather, approximately 158 vessels can be berthed if they are all large ones, while approximately 735 vessels can be moored if they are all small ones. However, with an increase in typhoon levels, the anchoring area for small vessels decreases. From the perspective of wave distribution in the fishing port, the number of large vessels moored was hardly affected by typhoons. This can be attributed to the breakwater, which significantly decreases the large wave height in the fishing port. Finally, a study on the framework of a method for hazard assessment of berthing capacity in the coming typhoon-driven storm waves was set up

Monitoring amyloid-β proteins aggregation based on label-free aptasensor

Amyloid-β oligomers (AβO) are important diagnostic markers for Alzheimer's disease (AD) and potential therapeutic targets for treating it. Herein, a simple and label-free electrochemical biosensor is presented for the specific recognition of AβO based on the binding of these biomarkers to ssDNA aptamer receptors. The ssDNA aptamer self-assembles to gold rod electrodes through Au-S interactions and binds specifically to AβO. The novel aptasensor shows a wide linear concentration range from 0.1 to 500 nM with a low detection limit of 0.03 nM as derived from electrochemical impedance spectroscopy invesastigations. Furthermore, owing to the high selectivity among Aβ species, this label-free sensor was used to monitor the process of Aβ protein aggregation, which was validated by atomic force microscope analysis. In addition, the aptasensor can be used to detect AβO in artificial CSF with satisfying accuracy. To our knowledge, it is first label-free aptasensor for an AβO assay based on EIS that works in artificial CSF and can be used for monitoring Aβ protein aggregation. These features, together with its easy fabrication, operation convenience, and effective regeneration, make our new aptasensor a promising tool for the early detection of AD and drug development by monitoring Aβ plaques degradation