Effectiveness Of Selection Method Research Articles

Mixing It Up: A Role-Theoretic Perspective on the Effects of Selection Methods on Governance

Mixing It Up: A Role-Theoretic Perspective on the Effects of Selection Methods on Governance

Effective Sensor Selection and Data Anomaly Detection for Condition Monitoring of Aircraft Engines.

In a complex system, condition monitoring (CM) can collect the system working status. The condition is mainly sensed by the pre-deployed sensors in/on the system. Most existing works study how to utilize the condition information to predict the upcoming anomalies, faults, or failures. There is also some research which focuses on the faults or anomalies of the sensing element (i.e., sensor) to enhance the system reliability. However, existing approaches ignore the correlation between sensor selecting strategy and data anomaly detection, which can also improve the system reliability. To address this issue, we study a new scheme which includes sensor selection strategy and data anomaly detection by utilizing information theory and Gaussian Process Regression (GPR). The sensors that are more appropriate for the system CM are first selected. Then, mutual information is utilized to weight the correlation among different sensors. The anomaly detection is carried out by using the correlation of sensor data. The sensor data sets that are utilized to carry out the evaluation are provided by National Aeronautics and Space Administration (NASA) Ames Research Center and have been used as Prognostics and Health Management (PHM) challenge data in 2008. By comparing the two different sensor selection strategies, the effectiveness of selection method on data anomaly detection is proved.

Chromatin condensation and morphometry of the bovine sperm head after in vitro sperm selection and capacitation

Methods of sperm selection and concentration are used to improve efficiency in obtaining viable embryos from in vitro fertilization procedures. Eighteen semen samples were submitted for selection with Percoll gradient and swim-up methods, followed by in vitro sperm capacitation with heparin, to assess the effect of selection method on chromatin condensation and sperm head morphometry. Smears were made at each stage of the process and stained with toluidine blue (TB). Digital images were analysed using computer algorithms developed with Scilab environment. After selection with either the Percoll gradient method sperm had less condensed chromatin. The swim-up method selected for smaller, more symmetrical heads with less variation in size when compared to semen samples that underwent no selection or were selected with the Percoll gradient method. The sperm also exhibited less condensed chromatin and more uniform head shape after heparin-induced capacitation.

Sheriffs' and police chiefs' leadership and management decisions in the local law enforcement budgetary process: an exploration

While almost all local government administrators frequently interact with municipal police chiefs and county sheriffs, there is a dearth of scholarly literature concerning the decision-making behaviours of these law enforcement executives. This study, as part of a larger project, explores decision-making as it pertains to the annual budgeting process, an important basis for county- or city-wide interaction. The central question of this study is: what is the effect of selection method on a local law enforcement manager's willingness to cooperate with a legislative body during a budget crisis? This exploratory research suggests that the disparate methods by which sheriffs and police chiefs obtain office (election versus appointment) play a role in each executive's decision-making behaviours, albeit in a counterintuitive way: sheriffs are more apt to demonstrate local government leadership through cooperation with the county legislature while police chiefs are more likely to focus their efforts on intradepartmental management.

Effect of selection method on genetic correlation and gain in a two-trait selection scheme

Summary Adverse genetic correlations between wood volume and quality traits are one of the main constraints in advancing radiata pine and other pine breeding programs. To overcome or deal with adverse genetic correlation in radiata pine and other conifer breeding programs, a Monte Carlo simulation study for the adversely correlated traits DBH and wood density was conducted using allele-based models. Two allelic models were generated for the study: a mixed-loci model using independent and pleiotropic loci (i.e. each locus affecting more than one trait) for adversely correlated traits and an all-antagonistic-pleiotropic-loci model. Selection was conducted for three scenarios: the first was based on a single trait, the second on index selection for two adversely correlated traits (DBH and wood density) with equal or, third, unequal economic weights. Results indicated that: 1. Adverse genetic correlation tends to increase under pleiotropic models with selection. 2. Genetic gains for adversely correlated traits (such as DBH and wood density) could be made for many generations with selective breeding if there are independent loci for individual traits. 3. New alleles (from infusion or mutation) with less antagonistic effect are required for further genetic gain in the two adversely correlated traits simultaneously if all independent alleles are fixed (i.e. without allelic variation) and pleiotropic loci with antagonistic effects are not fixed. 4. For short-term genetic gain in adversely correlated traits, selection based on two traits simultaneously is more effective than selection based on a single trait. Developing economic weights through breeding objectives is a sound approach for short-term breeding programs. Economic weights will influence genetic gain for individual traits and genetic correlation between traits. 5. For long-term genetic gain, dissecting the genetic basis of traits using a large association population is recommended. When the genetic mechanisms controlling adversely correlated traits are better understood, an allele model could be developed to study optimal strategies under different gene actions.

Sheriffs' and Police Chiefs' Leadership and Management Decisions in the Local Law Enforcement Budgetary Process: An Exploration

While almost all local government administrators frequently interact with municipal police chiefs and county sheriffs, there is a dearth of scholarly literature concerning the decision-making behaviours of these law enforcement executives. This study, as part of a larger project, explores decision-making as it pertains to the annual budgeting process, an important basis for county- or city-wide interaction. The central question of this study is: what is the effect of selection method on a local law enforcement manager's willingness to cooperate with a legislative body during a budget crisis? This exploratory research suggests that the disparate methods by which sheriffs and police chiefs obtain office (election versus appointment) play a role in each executive's decision-making behaviours, albeit in a counterintuitive way: sheriffs are more apt to demonstrate local government leadership through cooperation with the county legislature while police chiefs are more likely to focus their efforts on intradepartmental management.

Effect of culling on selection response using phenotypic selection or best linear unbiased prediction of breeding values in small, closed herds of swine.

Records from 7,200 separate closed herds with either 12 or 25 sows that were mated to either four or eight boars per year were simulated by computer. Effects of selection method, herd size, and contemporary group variability on average genetic change, genetic variance, and inbreeding over 10 yr of selection were analyzed for traits with heritabilities of .1, .3, and .6. Selection of replacement animals was on individual phenotype or BLUP of breeding value using a reduced animal model. For both of these selection methods, two culling schemes were imposed: 1) based only on involuntary culling because of losses due to conception rate and age and 2) when an available replacement animal was projected to be superior to an existing breeding animal in the herd in addition to the involuntary culling. The contemporary group standard deviation was set at either .1 or .5 of a phenotypic standard deviation. Selection with BLUP gave 72, 36, and 12% more genetic improvement for heritabilities of .1, .3, and .6, respectively, than selection on individual phenotype after 10 yr. However, inbreeding increased 20 to 52% more rapidly and there was a decrease in genetic variance. Culling based on Scheme 2 increased genetic improvement over Scheme 1 by about 75% with coincident increases in inbreeding level and decreases in genetic variance. The largest changes in inbreeding and genetic variance were associated with culling on BLUP. Culling when a superior animal was available with individual phenotype had little effect on inbreeding and genetic variance. Use of four boars rather than eight boars and 25 rather than 12 sows per herd increased genetic response. Use of four boars also increased inbreeding and decreased genetic variance. Genetic variance was higher in herds with 25 sows, but the size of the sow herd had little effect on inbreeding. Contemporary group variation influenced only the genetic response of individual phenotypic selection with culling.

Effectiveness of selection methods in chickpea Cicer arietinum under different environments

Three selection procedures, single-seed-descent, selection of the best 5% in both seed size and seed yield per plant were followed in two divergent crosses of chickpea under four environments in order to study the improvement of seed yield. Analysis of variance showed wide ranges of variability for all characters except days to maturity. Seed size (SSB) was found to be superior to single seed (SSD), followed by seed yield (YB), for developing high yielding lines. Fertility and spacing had no influence on the efficiency of any selection procedure indicating that selection under any environment is equally good.