Inefficient Tool Research Articles

Direct Numerical Control (NC) Path Generation: From Discrete Points to Continuous Spline Paths

Spline paths in NC machining are advantageous over linear and circular paths due to their smoothness and compact representation, thus are highly desirable in high-speed machining (HSM) where frequent change of tool position and orientation may lead to inefficient machining, tool wear, and chatter. This paper presents an approach for calculating spline NC paths directly from discrete points with controlled accuracy. Part geometry is represented by discrete points via an implicit point set surface (PSS). Cutter location (CL) points are generated directly from implicit part surfaces and interpolated by B-spline curves. A computing procedure for calculating maximum scallop height is given. The procedure is general and suitable for part surfaces in various surface representations provided that the closest distance from a point to the part surface can be calculated. Our results affirm that the proposed approach can produce high-quality B-spline NC paths directly from discrete points. The resulting spline paths make it possible for directly importing discrete points into Computer Numerical Control (CNC) machines for high-speed machining.

Regulating Front of Package Labeling: An Exercise in Futility?

Though presented as a way to reduce rates of obesity and chronic disease and help the American public select healthier foods, front-of-package labeling is an inefficient tool that operates within a processed food paradigm, thereby providing the food industry with yet another strategy to market nutritionally inferior foods to the general public.

Looking good versus doing good: Which factors take precedence when children learn about new tools?

We present two experiments exploring whether individuals would be persuaded to imitate the intentional action of an adult model whose actions suggest that the correct way to complete a task is with an inefficient tool. In Experiment 1, children ages 5–10 years and a group of adults watched an adult model reject an efficient tool in favor of one that was inefficient, but claim it was “made for” the task. Results indicated low rates of imitation of the model’s intentional choice until 9 and 10 years of age. In Experiment 2, children ages 3–11 years again watched a model reject a functional tool in favor of a nonfunctional one. This time, the demonstration took place on video. For half of the participants, the model from the video was present to offer a choice between the two tools (high-pressure condition), and for the other half, she was absent (low-pressure condition). Children also completed a social desirability questionnaire to explore relationships between imitation choices and personality. Results indicated that rates of imitation were associated with higher scores on the social desirability scale among children ages 3–7 years. Among 8- to 11-year-olds – and especially among 9- and 10-year-olds – the decision to copy the model’s intentional choice was more likely when the model was present than when she was absent. The findings reveal the contributions of age, personality, and social pressure to differences in imitation.

Improved in vitro dissolution parameters and in vivo hypolipidemic efficiency of atorvastatin calcium through the formation of hydrophilic inclusion complex with cyclodextrins

AbstractAn aim of the present study was to improve the dissolution of the inherently low water solubility hypolipidemic agent, Atorvastatin calcium (ATC), through the preparation and characterization of ATC with cyclodextrins (CDs) inclusion complexes employing different techniques. A second goal was to study the in vivo hypolipidemic efficacy of ATC‐complexes with enhanced dissolution characteristics. Inclusion complexation of ATC with β‐cyclodextrin (β‐CD) and hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) was evaluated in aqueous and solid states. ATC formed inclusion complexes with β‐CD and HP‐β‐CD depending to a great extent upon ATC ionization state. Evaporation and freeze‐drying were the most efficient techniques to achieve complexation. In contrast, kneading was an inefficient tool to create true inclusion complexes, which could reflect the hindrance of drug–CDs interactions in the semisolid medium. The ATC:CD ratio of 1:2 showed better dissolution characteristics compared to a 1:1 ratio. Moreover, the in vivo hypolipidemic activities of ATC‐CDs (β‐CD and HP‐β‐CD) complexes were greater (P<0.05) than the other investigated formulations. Thus the nature of the carrier did not play a critical role in the dissolution characteristics of the inclusion system. In contrast, the carrier molar ratio, and the employed complexation technique were found to be key factors in enhancing the ATC dissolution rate, yielding performances as well as the in vivo hypolipidemic efficacies. Drug Dev Res 72: 379–390, 2011. © 2011 Wiley‐Liss, Inc.

Iso-parametric CNC tool path optimization based on adaptive grid generation

The iso-parametric tool path is broadly used in CAM systems to machine sculptured surfaces. To satisfy tolerance constraints CAM systems usually adopt the smallest intervals across discrete tool paths, leading often to overlap and inefficient tool path. This paper presents a novel optimization scheme based on adaptive grid that can produce the optimal tool path on the basis of iso-parametric tool path and introduces the numerical method of generating the adaptive grid. When the generated optimal tool path has the same number of discrete tool path as the iso-parametric tool path, the optimal tool path will produce smaller machining errors. Or when the generated optimal tool path produces the same errors as the iso-parametric tool path, the optimal tool path will have fewer discrete tool paths and higher efficiency. This optimization scheme is robust, concise, and easy to be integrated into CAM systems to produce the optimal tool path automatically.

Why Tariffs, Not Subsidies? A Search for Stylized Facts

Abstract Barriers to trade are commonly viewed as a result of political systems in which politically influential groups benefit from and successfully lobby for protection. However, trade policy is a highly inefficient tool for redistributing income. Although recent theoretical research has focused on explanations of why (inefficient) trade barriers might be preferred to more direct means of redistribution, this research has been carried out with little empirical support. We address this gap in the literature with an exploratory cross-country empirical investigation of the economic factors correlated with a reliance on tariffs over subsidies. We find that the existing theoretical literature is consistent with the cross-country evidence.

Why Tariffs, not Subsidies? A Search for Stylized Facts

Barriers to trade are commonly viewed as a result of political systems in which politically influential groups benefit from and successfully lobby for protection. However, trade policy is a highly inefficient tool for redistributing income. Although recent theoretical research has focused on explanations of why (inefficient) trade barriers might be preferred to more direct means of redistribution, this research has been carried out with little empirical support. We address this gap in the literature with an exploratory cross-country empirical investigation of the economic factors correlated with a reliance on tariffs rather than subsidies, and find that the existing theoretical literature is consistent with the cross-country evidence.

Why Tariffs, Not Subsidies? A Search for Stylized Facts

Barriers to trade are commonly viewed as a result of political systems in which politically influential groups benefit from and successfully lobby for protection. However, trade policy is a highly inefficient tool for redistributing income. Although recent theoretical research has focused on explanations of why (inefficient) trade barriers might be preferred to more direct means of redistribution, this research has been carried out with little empirical support. We address this gap in the literature with an exploratory cross-country empirical investigation of the economic factors correlated with a reliance on tariffs over subsidies. We find that the existing theoretical literature is consistent with the cross-country evidence.

A Framework for Automatic Tool Selection in Integrated CAPP for Sheet Metal Bending

Sheet metal bending is a metal forming process, in which flat sheets are bent along straight bend lines in a specific bending sequence to form three-dimensional parts. A large number of tools with different characteristics can be used in this process. The task to choose the right tooling for a requested sheet metal part is however one of the bottle necks in process planning. An inefficient tool selection may result in failure of finding a feasible bending sequence. In previous work, methodologies for tool selection and optimization have been proposed. The presented paper describes a framework to implement these methodologies into a system that allows automatic tool selection in consistent consideration of bend sequencing. As a result, automated and optimized tool selection for sheet metal bending is achieved, as illustrated by performance test results for a robust software implementation.

Effects of controlled seasonal breeding on reproductive performance traits of pastoral goat herds in northern Kenya

A systematic breeding programme in a herd of Small East African goats was initiated in Isiolo District, northern Kenya. The study was undertaken to assess the effect of controlled seasonal breeding on the biological productivity of pastoral goat flocks. This paper reports the results of statistical analyses of reproductive performance traits (conception, abortion, birth, prolificacy, fecundity and weaning rates) measured for six mating seasons of 2 months duration each. It is shown that environmental seasonality as it prevails throughout northern Kenya significantly impacts individual reproductive traits in goats. The most pronounced influence was detected in relation to prolificacy and fecundity rates. However, the experimental mating season treatment could not be shown to have a statistically significant influence on reproductive traits. It is concluded that inter-year variability in seasonal environmental conditions were too high to permit a clear expression of statistical differences between the six mating seasons with respect to the traits considered. Nevertheless, it appears that joining does just before the onset of the long rains could produce the largest number of offspring per doe exposed. However, estimated weaning rates indicated that this superiority is entirely lost due to high mortality of young kids during the long dry season following thereafter. Controlled seasonal breeding, therefore, is most likely to be an inefficient management tool to improve reproductive performance of pastoral goat herds.

Linkage and molecular scanning analyses of MODY3/hepatocyte nuclear factor-1 alpha gene in typical familial type 2 diabetes: evidence for novel mutations in exons 8 and 10.

Mutations of the hepatocyte nuclear factor-1 alpha (HNF1 alpha) gene are an important cause of autosomal dominant diabetes with onset before age 25 yr [maturity-onset diabetes of the young (MODY)], and some regions of the HNF1 alpha gene appear to be hot spots for mutations. To evaluate the role of HNF1 alpha in the more common familial type 2 diabetes, we studied 62 families of Northern European origin by linkage analysis and molecular screening. Linkage was rejected under dominant models consistent with either late-onset type 2 diabetes or early-onset dominant diabetes. We used single strand conformation polymorphism analysis to screen 53 diabetic members of 36 families who reported diabetes diagnosed before age 40 yr, 9 members of 2 Utah families with typical MODY, and 24 additional members of families with possible linkage. One MODY family showed the previously reported frameshift mutation (P291fsinsC) in exon 4. Among the individuals with more typical type 2 diabetes, we identified the previously reported common polymorphisms, a new intronic polymorphism, and 3 common amino acid variants. We also identified 2 novel missense mutations that segregated with type 2 diabetes in 1 family each: lysine for glutamic acid substitution at codon 619 in exon 10 (E619K), and an arginine for threonine substitution at codon 537 in exon 8 (R537T) in a second family. The exon 8 mutation showed relatively low penetrance, and the role in this family remains uncertain. No coding mutations were identified in the family members screened on the basis of linkage but without early-onset diabetes. Although HNF1 alpha mutations are not a common cause of familial type 2 diabetes, they may account for 5% of families in which at least 1 member has onset of type 2 diabetes before age 40 yr. Incomplete penetrance and a high sporadic frequency make linkage an inefficient screening tool.

Can medical decisions be standardized? Should they be?

After a variety of regulatory and payment schemes have failed to stem the rising tide of health care cost, the Omnibus Budget Reconciliation Act of 1989 mandates the creation of a system of decision rules called practice parameters for appropriate medical action in many circumstances. A large body of practice guidelines already exists, but lacks the internal coherence required of a policy tool. Professional organizations therefore have developed attributes to achieve uniform style. However, little has been said or published about the constraints that might be imposed on the structure and content of an efficient and coherent system. The arguments presented here lead to the following conclusions: (a) process control is an inefficient tool to manage outcome--standards should reflect product control; (b) guidelines that proscribe are more likely to be supported by scientific data and consensus than those that prescribe; (c) the decision thresholds contained in such directives are policy choices rather than scientific imperatives; (d) neither decision analysis nor artificial intelligence is likely to readily influence medical decisions; and (e) as suggested by operations research, the development of practice parameters should concentrate on issues of therapeutic management in preference to issues of diagnostic activity.

Wavelet analysis of blade–vortex interaction noise

Fourier analysis techniques for analyzing helicopter noise signals have been shown to be an adequate, yet inefficient tool for the design of helicopter noise control systems. Impulsive sources of noise, such as blade–vortex interaction (BVI) noise cannot be localized in time without collecting relatively large amounts of data at high sampling rates. Attempts to minimize the BVI phenomenon through helicopter blade control schemes in the Fourier domain are inherently inefficient since the control matrices must account for the large number of Fourier components needed to represent the signal. Time-frequency representations, such as the wavelet representation, offer an efficient alternative to these Fourier domain methods. Wavelet analysis has been performed on an ensemble of helicopter noise signals. An interactive wavelet program was designed using quadrature mirror filters developed by S. Mallat. Using the bandpass representations of the signal, BVI noise was isolated and extracted from the overall helicopter noise signature. Future research will integrate the wavelet decomposition into an adaptive frequency domain controller for BVI noise minimization.a)With NASA Ames Res. Ctr., MS T-42, Moffett Field, CA 94035.

Effect of Horizontal and Vertical Permeability Restrictions in the Beryl Reservoir

This paper reports on the Beryl petroleum formation, the primary reservoir in the Beryl field, which has a complicated distribution of pressures and fluids controlled by horizontal and vertical permeability restrictions. Horizontal permeability restrictions, the result of extensive faulting, divide the reservoir into eight interrelated areas as determined by careful analyses of pressure and production histories and fluid monitoring. Vertical permeability restrictions, which are the consequence of thin lithologic breaks within the massive sandstone sequence, further divide the eight reservoir areas into seven layers, as evidenced by careful review of repeat formation tester (RFT) data, pressure-transient tests, cased-hole logs, and reservoir performance data. A detailed reservoir model identified areas and intervals of unswept hydrocarbons, resulting in an aggressive workover and drilling program. The model was an essential component in the success of the subsequent reservoir simulation.

Epilepsy: a disease audit.

An audit was made of the management of epilepsy in an Australian general practice using a computerized medical record system. The aim was to determine whether disease audit is practical and worth the effort involved. It was concluded that even a sophisticated medical record system can be an inefficient tool for the monitoring of chronic illness. A specific diagnostic and management protocol suitable for later computerization is required. A number of audit objectives were identified: (1) Has the practice diagnosed all cases of epilepsy as predicted by community prevalence studies? (2) Has it correctly classified these diagnoses and supported them by evidence from neurological referral and appropriate investigations (EEG and CT scan)? (3) To what extent has the practice adequately managed these patients? In particular, what percentage of patients have remained free of fits in the previous 12 months? (4) Has the doctor used the simplest drug regimen possible, preferably monotherapy, and avoided side effects? (5) Does the medical record allow analysis and effective audit? Audits of this type in a practice of this size requires a suitable practice register to identify the medical records to be analysed, otherwise a manual search of every record is a major deterrent to audit. Computerized records of the future should be designed so that data and analyses can be produced by automated printout.

Practical evaluation of some coal-cutting theories using a continuous miner : Roxborough, F F; Pedroncelli, E J Min Engr, V142, N252, Sept 1982, P145–156

As part of a major research programme in coalface mechanization, the South African Chamber of Mines has undertaken a comprehensive series of experiments in coal cutting using a Lee-Norse machine equipped with a special drum allowing four different levels of pick spacing, 50, 100, 150, and 200 mm to be investigated. Other modifications were made to the machine so that it could cut at drum speeds of 42, 35, 15 and 7 rpm and generate a much higher than normal sumping and shearing force capability at the cutting drum. The results of these experiments have shown that cutting efficiency improves markedly when operating at a large depth of cut, and that the optimum spacing for picks is between one and two times the depth of cut. This conforms well with laboratory and theoretical findings. However, the point-attack pick, which previously has been critized as an inefficient tool, was found in practice to be somewhat more efficient than the chisel-shaped pick at larger depths of cut, although its performance was generally inferior at shallow depths. (12 refs.)