3,246 research outputs found
Grey Critical Chain Project Scheduling Technique and Its Application
Based on the idea of Grey System and interval number coefficient notation, a Grey Critical Chain scheduling approach is studied. According to Grey system theory, the time of project or task completion can be considered as the object that extension is definite but intension is uncertain, which is coincident with the character of the project management. The Grey Critical Chain Scheduling Technique mainly aims at the single project time management, but the management idea can also be applied to the other knowledge areas of the project management. In this Technique, we improve the selection method of the buffer time in the Critical Chain, in order to obtain reasonable Feeding Buffer time and Project Buffer time. In this paper, we will use an example to discuss the Grey Critical Chain Scheduling Technique, compare Grey Critical Chain with Program Evaluation and Review Technique, Critical Chain and Fuzzy Critical Chain, analyze the advantages, disadvantages and applicable scope of their own. Key words: Critical Chain, Grey System, Interval Number, Schedule Management, Project Management Résumé: Sur la base de l’idée de Système Gris et la notation du coefficient de nombre d’intervalle, l’approche de pragrammtion d’une Chaîne Critique Grise est étudiée. Selon la théorie du Système Gris, le temps du projet ou de la tâche peut être considéré comme l’objet dont l’extention est définitive mais l’intention est incertaine, qui est conforme au caractère du management de projet. La Technique de Programmation de la Chaîne Critique Grise vise essentiellement le management du temps du projet simple, mais l’idée de management peut aussi être appliquée dans d’autres domaines du management de projet. Avec cette technique, nous améliorons la méthode de sélection du temps d’amortissement dans la Chaîne Critique afin d’obtenir le temps d’amortissement de l’alimentation raisonnable et le temps d’amortissement de projet. Dans l’article présent, nous allons utiliser un exemple pour discuter la Technique de Programmation de la Chaîne Critique Grise, comparer la Chaîne Critique Grise avec l’Evaluation du Programme et la Technique de révision, la Chaîne Critique et la Chaîne Critique Floue, et analyser leurs avantages, désavantages et champ d’application. Mots-Clés: Chaîne Critique, Système Gris, nombre d’intervalle, management de programme, management de proje
What about the contribution from reggeons in hard process of strong interactions?
We discuss in this paper the possible contributions from R_\rho(\rho-reggeon
associated with \rho meson) in DIS process on protons. Using results from
phenomenological analysis of high energy \pi-N charge-exchanged scattering
process, we get the expression of effective propagator of R_\rho and the
coupling constant \beta_\rho between R_\rho and light quarks. As a simple and
concrete example, we use them to evaluate the contributions of R_\rho to
F_2(x,Q^2) from charge-exchanged photoproduction quark-pair process,\gamma^* +
p-->n + q_u + \bar{q}_d (--> n + X), in HERA kinematical regions. For a
comparison, we also evaluate contributions both from pomeron and partons in the
same process. The ratio of contributions in F_2(x,Q^2) from R_\rho versus IP is
larger than 1%, therefore, the former may be tested experimentaly.Comment: 13 page, LaTex, 4 figure in postscript. To appear in Commu. in Theor.
Phy
Efficient Methods for Non-stationary Online Learning
Non-stationary online learning has drawn much attention in recent years. In
particular, dynamic regret and adaptive regret are proposed as two principled
performance measures for online convex optimization in non-stationary
environments. To optimize them, a two-layer online ensemble is usually deployed
due to the inherent uncertainty of the non-stationarity, in which a group of
base-learners are maintained and a meta-algorithm is employed to track the best
one on the fly. However, the two-layer structure raises the concern about the
computational complexity -- those methods typically maintain base-learners simultaneously for a -round online game and thus perform
multiple projections onto the feasible domain per round, which becomes the
computational bottleneck when the domain is complicated. In this paper, we
present efficient methods for optimizing dynamic regret and adaptive regret,
which reduce the number of projections per round from to
. Moreover, our obtained algorithms require only one gradient query and one
function evaluation at each round. Our technique hinges on the reduction
mechanism developed in parameter-free online learning and requires non-trivial
twists on non-stationary online methods. Empirical studies verify our
theoretical findings.Comment: preliminary conference version appeared at NeurIPS 2022; this
extended version improves the paper presentation, further investigates the
interval dynamic regret, and adds two applications (online non-stochastic
control and online PCA
Geolocation of a Known Altitude Target Using TDOA and GROA in the Presence of Receiver Location Uncertainty
This paper considers the problem of geolocating a target on the Earth surface using the target signal time difference of arrival (TDOA) and gain ratio of arrival (GROA) measurements when the receiver positions are subject to random errors. The geolocation Cramer-Rao lower bound (CRLB) is derived and the performance improvement due to the use of target altitude information is quantified. An algebraic geolocation solution is developed and its approximate efficiency under small Gaussian noise is established analytically. Its sensitivity to the target altitude error is also studied. Simulations justify the validity of the theoretical developments and illustrate the good performance of the proposed geolocation method
Design and implementation of wire tension measurement system for MWPCs used in the STAR iTPC upgrade
The STAR experiment at RHIC is planning to upgrade the Time Projection
Chamber which lies at the heart of the detector. We have designed an instrument
to measure the tension of the wires in the multi-wire proportional chambers
(MWPCs) which will be used in the TPC upgrade. The wire tension measurement
system causes the wires to vibrate and then it measures the fundamental
frequency of the oscillation via a laser based optical platform. The platform
can scan the entire wire plane, automatically, in a single run and obtain the
wire tension on each wire with high precision. In this paper, the details about
the measurement method and the system setup will be described. In addition, the
test results for a prototype MWPC to be used in the STAR-iTPC upgrade will be
presented.Comment: 6 pages, 10 figues, to appear in NIM
Non-coding RNAs participate in the regulatory network of CLDN4 via ceRNA mediated miRNA evasion
AbstractThousands of genes have been well demonstrated to play important roles in cancer progression. As genes do not function in isolation, they can be grouped into “networks” based on their interactions. In this study, we discover a network regulating Claudin-4 in gastric cancer. We observe that Claudin-4 is up-regulated in gastric cancer and is associated with poor prognosis. Claudin-4 reinforce proliferation, invasion, and EMT in AGS, HGC-27, and SGC-7901 cells, which could be reversed by miR-596 and miR-3620-3p. In addition, lncRNA-KRTAP5-AS1 and lncRNA-TUBB2A could act as competing endogenous RNAs to affect the function of Claudin-4. Our results suggest that non-coding RNAs play important roles in the regulatory network of Claudin-4. As such, non-coding RNAs should be considered as potential biomarkers and therapeutic targets against gastric cancer.</jats:p
Determination of dissolved nitric oxide in coastal waters of the Yellow Sea off Qingdao
We developed a new method for the determination of dissolved nitric oxide (NO) in discrete seawater samples based on the combination of a purge-and-trap setup and a fluorometric detection of NO. 2,3-diaminonaphthalene (DAN) reacts with NO in seawater to form the highly fluorescent 2,3-naphthotriazole (NAT). The fluorescence intensity was linear for NO concentrations in the range from 0.14 to 19 nmol L−1. We determined a detection limit of 0.068 nmol L−1, an average recovery coefficient of 83.8 % (80.2–90.0 %), and a relative standard deviation of ±7.2 %. With our method we determined for the first time the temporal and spatial distributions of NO surface concentrations in coastal waters of the Yellow Sea off Qingdao and in Jiaozhou Bay during a cruise in November 2009. The concentrations of NO varied from below the detection limit to 0.50 nmol L−1 with an average of 0.26 ± 0.14 nmol L−1. NO surface concentrations were generally enhanced significantly during daytime, implying that NO formation processes such as NO2− photolysis are much higher during daytime than chemical NO consumption, which, in turn, lead to a significant decrease in NO concentrations during nighttime. In general, NO surface concentrations and measured NO production rates were higher compared to previously reported measurements. This might be caused by the high NO2− surface concentrations encountered during the cruise. Moreover, additional measurements of NO production rates implied that the occurrence of particles and a temperature increase can enhance NO production rates. With the method introduced here, we have a reliable and comparably easy to use method at hand to measure oceanic NO surface concentrations, which can be used to decipher both its temporal and spatial distributions as well as its biogeochemical pathways in the oceans
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