Mitigating forecast errors by lot-sizing rules in ERP-controlled manufacturing systems

As enterprise resource planning (ERP) becomes the dominant management software in manufacturing and distribution systems in various industries, some problems associated with its origin, material requirements planning (MRP), still need to be resolved. We examine the effect of forecasting errors, one of the common operational problems in any business operation, in the context of an ERP-controlled manufacturing system. We consider a mitigating remedy, the use of a lot-sizing rule, to cope with the consequences of forecasting inaccuracy without resorting to costly inventory-oriented buffers. An ERP-controlled manufacturing system is simulated to see how these lot-sizing rules mitigate the forecast errors and subsequently generate acceptable system performance. The simulation results should help ease ERP users’ fear of committing another fatal error in demand forecasts, instead encouraging them to consider proper lot-sizing rules to cope with forecast errors.     

Selective cardiovascular effects of stress and cigarette smoking in young women.

Used a 2?×?2 (smoke/no smoke?×?stress/no stress) factorial design to evaluate the impact of stress and smoking on the cardiovascular responses of 43 female undergraduates and college staff (mean age 20.7 yrs). The stressor was a video game. Results reveal that the combination of stress and cigarette smoking produced blood pressure and heart rate responses that were larger than the additive effects of smoking and stress taken separately. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Glypican 3 and glypican 4 are juxtaposed in Xq26.1

This paper reports the development of a dual column system for the simultaneous separation of fluorescent short-chain ceramide, 6-[(7-nitrobenz-2-oxa-1,3,-diazol-4-yl[NBD])amino]hexanoyl-sphingo sine and its metabolites, C6-NBD-sphingomyelin and C6-NBD-glucosylceramide, as well as the fluorescent derivatives of choline and serine phosphatides. The method enables the separation of these lipids in a single run on the basis of the polarity of their headgroups and hydrophobicity of their acyl backbone. The fluorescent properties of the NBD-label make it possible to quantitate small amounts of NBD-lipid analogues. The sensitivity of the presented method thus permits the use of small sample volumes and the determination of NBD-lipid analogues secreted into mouse bile directly, without prior extraction or concentration steps.     

Modification of a vinyl glove into a dental dam for patients sensitive to latex rubber

Transurethral microwave thermotherapy (TUMT) is a unique and promising method of treating benign prostatic hyperplasia. Clinical outcomes are related to thermal dose delivered. In 359 consecutive patients, strategies to increase thermal dose using the FDA-approved Prostasoft 2.0 delivered a mean of 148 kJ, which was almost 50 kJ more than the U.S. FDA trials. These strategies include careful preoperative patient teaching, exclusion of very small prostates, ketorolac, prewarming of the prostaprobe, antitorque of the rectal probe, use of urethral cooling adjustment during power ramping, and no manual power interruptions. Clinical outcomes improved without any significant adverse events. Peak urinary flow increased in 4 months by 5.5 mL/sec.     

Isolation and characterization of 1,3-dimethylisoguanine from the Bermudian sponge Amphimedon viridis

The new compound 1,3-dimethylisoguanine has been isolated and characterized from the Bermudian sponge Amphimedon viridis. Chemical conversion of the natural product to theophylline and 2D NMR methods were used to determine the position of the methyl groups on the purine ring. Analysis of the mass spectral fragmentation pattern allowed assignment of the purine ring as isoguanine.     

Naamidine A is an antagonist of the epidermal growth factor receptor and an in vivo active antitumor agent

The known 2-aminoimidazole alkaloid naamidine A (1) was isolated from a Fijian Leucetta sp. sponge as an inhibitor of the epidermal growth factor (EGF) receptor. The compound exhibited potent ability to inhibit the EGF signaling pathway and is more specific for the EGF-mediated mitogenic response than for the insulin-mediated mitogenic response. Evaluation in an A431 xenograft tumor model in athymic mice indicated that naamidine A exhibited at least 85% growth inhibition at the maximal tolerated dose of 25 mg/kg. Preliminary mechanism of action studies indicate that the alkaloid fails to inhibit the binding of EGF to the receptor and has no effect on the catalytic activity of purified c-src tyrosine kinase.     

Growth, reproductive performance, mammary development, and milk production of beef heifers as influenced by prepubertal dietary energy and administration of bovine somatotropin

Three trials with 156 crossbred heifers were used to determine the effects of dietary energy and bovine somatotropin administration on subsequent heifer productivity. In Trial 1, heifer calves were weaned from their dams (n = 28; 113 +/- 13 d of age) and assigned to a 2 x 2 factorial arrangement of moderate (MDE) or high dietary energy (HDE) and injections of vehicle (VEH) or 250 mg of bovine somatotropin (bST) every 14 d. Heifer calves in Trial 2 (n = 28; 123 +/- 20 d of age) and Trial 3 (n = 100; 134 +/- 22 d of age) nursed their dams while grazing pasture and received no creep feed (MDE) or ad libitum access to creep feed (HDE) and received VEH or bST as in Trial 1. Treatments were administered for 112 d and heifers within trial were managed alike after that time. There were no dietary treatment x bST treatment interactions for any of the variables analyzed (P > .05). Dietary energy did not affect daily gain in Trial 1; however, heifers receiving HDE in Trials 2 and 3 had greater weight, hip height growth, and fat thickness (P < .01) by the end of the treatment period. Treatment with bST increased gain in Trials 1 and 2 (P < .01) but did not affect growth in Trial 3. There were trends in all trials for HDE to reduce age at puberty (P < .15), but there were no consistent effects of bST on reproductive measures. Mammary gland composition and milk production were unaffected by treatment in Trial 1. In Trial 2, HDE decreased subsequent milk production, calf weaning weight, and mammary dry fat free tissue and DNA (P < .05). Treatment with bST in Trial 3 tended (P = .08) to result in greater milk production and increased calf weaning weights (P < .05). We conclude that bST treatment may enhance growth with no effect on reproduction. Treatment with bST did not overcome deleterious effects of HDE on milk production but may play an important role in mammogenesis.     

Effects of prenatal androgenization, melengestrol acetate, and Synovex-H on feedlot performance, carcass, and sensory traits of once-calved heifers

Three studies were designed using a 2 x 2 factorial arrangement of treatments within each experiment to evaluate the effects of various management techniques on growth and carcass traits of once-calved heifers. In Exp. 1, 33 yearling (16 control [C] and 17 prenatally androgenized [PA]) and 39 once-calved (20 C and 19 PA) nonpregnant heifers were used to evaluate the effects of age and PA. Once-calved heifers were approximately 31 kg heavier (P < .03) on-test, initially consumed 11% more (P < .01) DM, and gained 11% faster (P < .08), but had similar (P = .44) gain to feed ratios (.138 vs. .131) as yearlings. Growth performance was not affected by PA. The yearling and once-calved heifers were then slaughtered at approximately 707 and 1,080 d of age, respectively. Despite maturity differences (P < .01), marbling scores (P = .26) and percentage of choice carcasses (P = .27) were similar. However, on the basis of newly accepted grading changes, percentage of once-calved heifer carcasses grading choice decreased from 57.3 to 34.4%. Organoleptic properties did not differ. Experiments 2 and 3 were then conducted to evaluate effects of commercially available products (melengestrol acetate [MGA] and Synovex-H) on feedlot characteristics of heifers following weaning of their first calf. In Exp. 2, 48 once-calved Simmental-based heifers were fed during the summer to a constant compositional fat thickness of .8 cm. Experiment 3 was conducted in the late fall and early winter, during which 52 moderately sized heifers were fed for 116 d postweaning and slaughtered. Performance of heifers in Exp. 2 was not affected by MGA. However, heifers fed MGA in Exp. 3 gained 9% faster (P < .05) than controls. In Exp. 2, Synovex-H tended to improve ADG (P < .09) and feed efficiency (P < .07), but did not affect performance in Exp. 3. Most carcass traits were not affected by either treatment. Nonpregnant, once-calved heifers seem to have a large capacity for efficient weight gain as compared with yearling heifers. However, hormonal compounds, such as testosterone propionate provided pre- or postnatally (Synovex-H), and MGA do not appear to provide the consistent, positive responses often seen with younger, more typical feedlot heifers.     

Discovery of invariants through automated theory formation

Refinement is a powerful mechanism for mastering the complexities that arise when formally modelling systems. Refinement also brings with it additional proof obligations—requiring a developer to discover properties relating to their design decisions. With the goal of reducing this burden, we have investigated how a general purpose automated theory formation tool, HR, can be used to automate the discovery of such properties within the context of the Event-B formal modelling framework. This gave rise to an integrated approach to automated invariant discovery. In addition to formal modelling and automated theory formation, our approach relies upon the simulation of system models as a key input to the invariant discovery process. Moreover we have developed a set of heuristics which, when coupled with automated proof-failure analysis, have enabled us to effectively tailor HR to the needs of Event-B developments. Drawing in part upon case study material from the literature, we have achieved some promising experimental results. While our focus has been on Event-B, we believe that our approach could be applied more widely to formal modelling frameworks which support simulation.     

Diesel particle filter and fuel effects on heavy-duty diesel engine emissions

The impacts of biodiesel and a continuously regenerated (catalyzed) diesel particle filter (DPF) on the emissions of volatile unburned hydrocarbons, carbonyls, and particle associated polycyclic aromatic hydrocarbons (PAH) and nitro-PAH, were investigated. Experiments were conducted on a 5.9 L Cummins ISB, heavy-duty diesel engine using certification ultra-low-sulfur diesel (ULSD, S ≤ 15 ppm), soy biodiesel (B100), and a 20% blend thereof (B20). Against the ULSD baseline, B20 and B100 reduced engine-out emissions of measured unburned volatile hydrocarbons and PM associated PAH and nitro-PAH by significant percentages (40% or more for B20 and higher percentage for B100). However, emissions of benzene were unaffected by the presence of biodiesel and emissions of naphthalene actually increased for B100. This suggests that the unsaturated FAME in soy-biodiesel can react to form aromatic rings in the diesel combustion environment. Methyl acrylate and methyl 3-butanoate were observed as significant species in the exhaust for B20 and B100 and may serve as markers of the presence of biodiesel in the fuel. The DPF was highly effective at converting gaseous hydrocarbons and PM associated PAH and total nitro-PAH. However, conversion of 1-nitropyrene by the DPF was less than 50% for all fuels. Blending of biodiesel caused a slight reduction in engine-out emissions of acrolein, but otherwise had little effect on carbonyl emissions. The DPF was highly effective for conversion of carbonyls, with the exception of formaldehyde. Formaldehyde emissions were increased by the DPF for ULSD and B20.