Stochastic Time–Cost Optimization Model Incorporating Fuzzy Sets Theory and Nonreplaceable Front

In a real construction project, the duration and cost of each activity could change dynamically as a result of many uncertain variables, such as weather, resource availability, productivity, etc. Managers/planners must take these uncertainties into account and provide an optimal balance of time and cost based on their own experience and knowledge. In this paper, fuzzy sets theory is applied to model the managers’ behavior in predicting time and cost pertinent to a specific option within an activity. Genetic algorithms are used as a searching mechanism to establish the optimal time–cost profiles under different risk levels. In addition, the nonreplaceable front concept is proposed to assist managers in recognizing promising solutions from numerous candidates on the Pareto front. Economic analysis skills, such as the utility theory and opportunity cost, are integrated into the new model to mimic the decision making process of human experts. A simple case study is used for testing the new model developed. In comparison with the previous models, the new model provides managers with greater flexibility to analyze their decisions in a more realistic manner. The results also indicate that greater robustness may be achieved by taking some risks. This research is relevant to both industry practitioners and researchers. By incorporating the concept of fuzzy sets, managers can represent the range of possible time–cost values as well as their associated degree of belief. The model presented in this paper can, therefore, support decision makers in analyzing their time–cost optimization decision in a more flexible and realistic manner. Many novel ideas have also been incorporated in this paper to benefit the research community. Examples of these include the use of fuzzy sets theory, nonreplaceable front concept, utility theory, opportunity cost, etc. With suitable modifications, these concepts can be applied to model to other similar optimization problems in construction.     

Adapting technology: effect of high-involvement HRM and organisational trust

This study is designed to empirically test a model of high-involvement human resource management (HIHRM), organisational trust, and technology adaptation grounded on social exchange theory in the context of the private banking sector. The proposed model intends to add to the understanding of the effect of HIHRM on technology adaptation via the mediating influence of organisational trust. Frontline employees were surveyed using a self-administered questionnaire. Results from partial least square-structural equation modelling suggest that there is a significant influence of HIHRM on technology adaptation. Organisational trust further mediates the relationship. Thus, this paper finds an answer to the ‘black box’ of human resource management (HRM) practices, explaining how HIHRM influences employees’ attitudes towards technology adaptation. The study can help management have a better understanding of the importance of employee involvement-oriented HRM in introducing and implementing a new technology through the integration of trust processes in the organisation.     

Identification of a triacylglycerol lipase gene family in Candida deformans: molecular cloning and functional expression

The yeast Candida deformans CBS 2071 produces an extracellular lipase which was shown to catalyse the production of various esters by the esterification of free fatty acids, even in the presence of a large molar excess of water. To clone the gene encoding this extracellular lipase, Saccharomyces cerevisiae was transformed with C. deformans genomic libraries and screened for lipolytic activity on a medium containing rapeseed oil emulsion and rhodamine B. Three members of a lipase gene family (CdLIP1, CdLIP2 and CdLIP3) were cloned and characterized. Each deduced lipase sequence has a Gly-His-Ser-Leu-Gly-(Gly/Ala)-Ala conserved motif, eight cysteine residues and encodes an N-terminal signal sequence. MALDI-TOF mass spectrometry analysis of a proteolytic digest of the lipase produced was used to obtain experimental evidence that the CdLIP1 gene encoded the extracellular lipase. Recombinant expression studies confirmed that the cloned genes encoded functional lipases. The three lipases are very similar to lipases from the related species Yarrowia lipolytica. Significant homologies were also found with several yeast and fungal lipases. As C. deformans CBS 2071 was previously considered to be synonymous with Y. lipolytica, the strains were compared for the extent of nucleotide divergence in the variable regions (D1/D2) at the 5'-end of the large-subunit (26S) ribosomal DNA (rDNA) gene. This rDNA region has diverged sufficiently to suggest that C. deformans is a separate species. The nucleotide sequences of the CdLIP1, CdLIP2 and CdLIP3 genes will appear in the EMBL nucleotide sequence database under Accession Nos AJ428393, AJ428394 and AJ428395, respectively.     

Organocatalytic Radical Involved Oxidative Cross‐Coupling of N‐Hydroxyphthalimide with Benzylic and Allylic Hydrocarbons

The cross‐coupling reaction between N‐hydroxyphthalimide and various benzylic and allylic hydrocarbons was realized through an organocatalytic radical‐mediated process involving C(sp³) O bond formation using tert‐butyl hydroperoxide (t‐BuOOH) as an oxidant and tetra‐n‐butylammonium iodide [(n‐Bu]₄NI] as a catalyst, during which the phthalimide N‐oxyl (PINO) radical and benzylic and allylic radicals were generated in situ and underwent the selective radical/radical cross‐coupling reaction. This novel method provides a convenient metal‐free approach to the synthesis of O‐alkylated hydroxy imides under mild reaction conditions.

     

On the validity of the California Psychological Inventory Socialization Scale: A multivariate approach.

Isolated groups homogeneous in role-taking ability and described them on dimensions of the California Psychological Inventory (CPI) Socialization (So) scale. Ss were 189 Swedish delinquent and nondelinquent 19-31 yr old males. 6 subscales were constructed by factor analysis. A latent profile analysis of responses to 18 items, selected from the subscales, yielded a low (n = 78 and a high (n = 106) socialization group. 75% of the delinquents were classified as the low group. In a discriminant analysis of subscale scores, the latent profile analysis groups were significantly separated. 5 subscale means were significantly different. Results support the validity of some of the subscales as indicators of the role-taking construct underlying the So scale. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparison of self-reported drug use with a urine drug screen in a working population: Correction.

Reports an error in the original article by R. Bharucha-Reid et al (Experimental and Clinical Psychopharmacology, 1995, Vol 3 [3], 280–286). Rachel Kaufmann was inadvertently misspelled. (The following abstract of this article originally appeared in record 1996-92908-001.) This study summarized information on 162 workers who completed urine screen and self-report concerning drug use. It is the first to compare self-report of drug use in the workplace with a urine screen in which individual participant (nonaggregate) data were used. The findings indicate that agreement between the 2 methods of drug detection, although statistically significant, is at best only moderate. The level of agreement was consistent for segments of the sample when divided by sociodemographic characteristics. Although urine screen may be the more reliable and accurate method of detecting prevalence of drug use, self-report must be considered to assess drug use histories and the role of other variables. These 2 methods should be considered as complementary assessment techniques; the appropriate method depends on the conditions and purposes of the drug use study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermoset IM-LSI-based C/C-SiC: Influence of flow direction and weld lines on microstructure and mechanical properties

The production of ceramic matrix composites (CMC) based on C/C-SiC is still very cost-intensive and therefore only economical for a few applications. The fabrication of the preforms involves many costs that need to be reduced. In this work, the shaping of the CFRP-preforms is realized by thermoset injection molding, which enables large-scale production. The polymeric matrix used is a multi-component matrix consisting of novolak resin, curing agent and lubricant. Six millimeter chopped carbon fiber with a proportion of 50 wt.% were used as a reinforcement. These ingredients are processed by an industrial equipment for compounding and injection molding in order to manufacture a CFRP demonstrator representing a brake disc. Test specimens are cut out of the demonstrator in different directions in order to investigate influences of flow direction and weld lines on microstructural and mechanical properties. Afterward, the CFRP samples were converted to C/C-SiC composites by the liquid silicon infiltration process. The article addresses the flow behavior of the compound during the injection molding and the building of the weld lines in the demonstrator. In addition, results of the directional dependence of the microstructural and mechanical properties within the fabricated disc in the different production steps are presented.     

Compliant activity rather than difficulty accelerates thought probe responsiveness and inhibits deliberate mind wandering

ABSTRACT

Mind wandering is a commonly intruding cognitive state that leads to diminished performance and increased error risk during a primary task. A controversy over whether easier or more difficult tasks increase mind wandering has led to mind wandering being proposed as two different states: deliberate and spontaneous. We hypothesise that forced engagement via persistent compliant activity may both increase responsiveness and inhibit non-instrumental activities including deliberate mind wandering. Twenty-eight healthy adults interacted with 2 pairs of stimuli, each pair having one low-interactivity version and a high-interactivity version requiring compliant activity. Mind wandering was assessed by thought probes, and subjective responses were rated using visual analogue scales. Reaction times were measured using Superlab. Compliant activity decreased the prevalence of deliberate mind wandering episodes but not of overall mind wandering. Thought probe durations were accelerated significantly by compliant activity, near-significantly by thinking on-task thoughts, and additively by the combination of both. Deliberate and spontaneous mind wandering elicited equivalent thought probe durations. We conclude that compliant activity works synergistically with lack of mind wandering to accelerate the difficult task of thought probe response but not simple reaction times. These results fit with an arousal model but not the attentional resources model.     

Digital titration: Automated image acquisition and analysis of load and growth of Chlamydophila psittaci

Traditionally, the amount of infective chlamydiae in a given sample is determined by inoculating dilution series into cell cultures and physically counting chlamydial inclusions. This approach is time consuming, tedious, and error prone, mainly when dealing with high titers. Therefore, this paper describes a largely automated technique that was developed to standardize the determination of chlamydial load in vitro. Cells are fixed at 36 h post-inoculation and bacteria visualized using standard immunological detection methods. Consequently, for 81 microscopic fields, an image is recorded at the interpolated focal plane. These images are then automatically processed using an ImageJ plugin and the obtained results are imported into Excel to determine the number of inclusion forming units per mL in the sample. The main advantage of this technique is that no or minimal sample dilution is required, thus minimizing dilution errors. In addition, this technique was employed during the early, middle and late growth stages of the chlamydial developmental cycle and results correlated well (P < 0.01) with 16S rRNA values from previous experiments, thereby proving its suitability to follow chlamydial growth in vitro. The method described is highly suitable for high throughput titration of cell culture inoculated samples and assessment of possible antichlamydial effects of novel compounds throughout the chlamydial growth cycle. Microsc. Res. Tech., 2009. © 2009 Wiley-Liss, Inc.