Application of the Colorado River Simulation System Model to Evaluate Water Shortage Conditions in the Central Arizona Project

Central Arizona Project (CAP) is currently enhancing its water resources modeling capabilities to improve water resources management and planning activities and to better understand the inherent complexities of the Colorado River Basin system. CAP modeling activities in the Colorado River Basin extensively utilize the Colorado River Simulation System (CRSS) model. CRSS is a sophisticated object-oriented surface water model developed under the RiverWare modeling environment and maintained by the United States Bureau of Reclamation (USBR). CRSS incorporates important aspects of the Colorado River Basin: main stem, reservoirs along the river, water inflows to the river, and points of water deliveries. By using the object-oriented and rule-based capabilities of RiverWare, CRSS has embedded the rules of the Law of the River. These set of rules guide the operation and management of the Colorado River Basin’s surface water supply. This analysis executes CRSS short term simulations to evaluate the vulnerability of water deliveries to CAP from the Colorado River under different extreme hydrological and policy conditions. In the future, this type of analysis will provide key input for other CAP models, aimed to improve a quantitative understanding of the impacts of different uncertain and complex scenarios: drought conditions, future user demand behavior, reservoir operation, and optimize water recovery as a part of Arizona Water Bank Authority (AWBA), among others.     

A hybrid differential evolution and estimation of distribution algorithm based on neighbourhood search for job shop scheduling problems

Job shop scheduling problem (JSSP) is a typical NP-hard problem. In order to improve the solving efficiency for JSSP, a hybrid differential evolution and estimation of distribution algorithm based on neighbourhood search is proposed in this paper, which combines the merits of Estimation of distribution algorithm and Differential evolution (DE). Meanwhile, to strengthen the searching ability of the proposed algorithm, a chaotic strategy is introduced to update the parameters of DE. Two mutation operators are adopted. A neighbourhood search (NS) algorithm based on blocks on critical path is used to further improve the solution quality. Finally, the parametric sensitivity of the proposed algorithm has been analysed based on the Taguchi method of design of experiment. The proposed algorithm was tested through a set of typical benchmark problems of JSSP. The results demonstrated the effectiveness of the proposed algorithm for solving JSSP.     

Comments on “The Model Checker SPIN”

The paper by G.J. Holzmann (see ibid., vol.23, no.5, p.279-95, 1997) describes how to apply SPIN to the verification of a synchronization algorithm (L.M. Ruane, 1990) in process scheduling of an operating system. We report an error in the verification model presented by G.J. Holzmann and present a revised model with verification result. Our result explains the reason why SPIN found the race condition in the synchronization algorithm. We also show that the suggested fix by G.J. Holzmann is incorrect     

Effect of early seed removal during fermentation on proanthocyanidin extraction in red wine: A commercial production example

Wines (Vitis vinifera L. cv. Merlot) were made by a commercial winery to examine the effects of seed removal at ∼10 °Brix on the extraction of proanthocyanidins during fermentation. Seeds were removed at the point when they fell to the bottom of the fermenter, and were thus easily removed during regular pump-over operations. Proanthocyanidin extraction was compared to wine made from traditional winemaking regime in which no seed removal occurred. Proanthocyanidin differences observed in the wines were minor. The control wine contained a slightly higher percentage molar proportion of seed proanthocyanidins ((−)-epicatechin-3-O-gallate extension and terminal subunits), demonstrating higher seed tannin extraction, and the seed removed wine contained a higher percentage molar proportion of skin proanthocyanidin indicators ((−)-epigallocatechin extension subunits). Seed removed Merlot wines had higher concentrations of total anthocyanins. Minor differences in colour measurement values between the two wines were also observed. The control wine was slightly more orange (larger hue angle, h°), lighter (larger L^∗ value), and more saturated (higher chroma value, C^∗) in colour. This appears to be the first paper to report the effects of early seed removal in Merlot winemaking, and demonstrates how winery tannin management techniques contribute to proanthocyanidin composition.     

Detecting changes in autoregressive processes with X¯ and EWMA charts

The traditional use of control charts necessarily assumes the independence of data. It is now recognized that many processes are autocorrelated thus violating the fundamental assumption of independence. As a result, there is a need for a broader approach to SPC when data are time-dependent or autocorrelated. This paper utilizes control charts with fixed control limits for residuals to monitor the performance of a process yielding time-dependent data subject to shifts in the mean and the autocorrelation structure. The effectiveness of the framework is evaluated by an average run length study of both X¯ and EWMA charts using analytical and simulation techniques. Average run lengths are tabulated for various process disturbance scenarios, and recommendations for the most effective monitoring tool are made. The findings of this research present motivation to extend the traditional paradigms of a shifted process (e.g., mean and/or variance). The results show that decreases in the underlying time series parameters are practically impossible to detect with standard control charts. Furthermore, the practitioner is motivated to employ runs rules since the runs are more likely with time-dependent observations.     

Mining for Computing Jobs

Understanding the types of jobs, the skills used in those jobs, and the relative distribution of jobs available in the computing professions is imperative in today's economy. This article uses a Web content mining approach to address these information needs. With this approach, the authors identified 20 categories of current computing jobs and their associated skills needs. During the study period, they extracted and analyzed nearly a quarter million job ads from Monster.com, HotJobs.com, and SimplyHired.com. The resulting data will be useful to current computing professionals, prospective employees, human-resource executives, and educational institutions.     

Effects of Organic Cation Structure on Behavior of Organobentonites

This study quantified the effects of four quaternary ammonium cations (TMA, DTMA, HDTMA, and BTEA) on the mechanical properties of a modified Wyoming bentonite. TMA, DTMA, and HDTMA are organic cations with alkyl chains of lengths 1, 10, and 16 carbons, while BTEA has a benzyl ring attached. Substitution of the organic cations onto the bentonite surfaces altered the soil's behavior by: (1) reducing the soil's specific gravity, with the specific gravity decreasing linearly as the size of the exchanged organic cation was increased; (2) dramatically reducing the soil's liquid limit (from 458% for the unmodified bentonite to 52–65% for the organoclays); (3) reducing the compressibility of the clays (from a compression index of 5.5 for the unmodified bentonite to compression indices of 0.47–0.59 for the organoclays); (4) reducing the swell potential (Cs = ～1.5 for bentonite compared with 0.035–0.083 for the organoclays); and (5) increasing the direct shear friction angle (7° for unmodified bentonite compared with 34–37° for the organoclays).