Optimization of process of stocks controling based on group ordering the goods

W praktyce gospodarczej bardzo często występuje problem zamawiania różnorodnych asortymentów od jednego bądź wielu dostawców. Związany jest on z tzw. efektem skali, czyli obniżeniem kosztów, a także uzyskaniem rabatów wraz z zamawianiem surowców, transportem, produkcja oraz magazynowaniem produktów w większych partiach. Rozwiązanie tego problemu zostanie przedstawione na przykładzie wybranej klasycznej metody zamawiania grupowego, jaką jest analiza pokrycia.In the article it is proposed an innovative aspect for the process of stocks controlling. It is presented an opportunity using of nonlinear programming for the optimization of process of the group ordering the goods, which is the 'coverage analysis'. The attention is paid for the formation of scale effect and the occurrence of trade-off relation, connected to safety of the customer needs by the minimization the general costs of maintenance the stocks

Evaluation model of the companies operating within logistic network

In the paper authors presented concept of evaluation of complex systems such as logistic companies which operate in competitive environment. Authors also highlighted the importance of the evaluation problem in operational activity, particularly in the properly prepared procedures to be followed, consisted of several stages adapted to currently conducted research. Properly executed evaluation of companies enables customers to take right decisions on contracting services and stimulate the development of those companies. It should be noted that the proposed algorithmic model of assessment may be particularly useful for assessment of complex logistics systems. Characteristics of the respective phases developed procedure allowed to indicate that it is important to select of appropriate criteria and evaluation methods. It was pointed out that particularly useful for assessing of logistics companies are multi-criteria analysis methods, because they allow to examine objects in a holistic manner, taking into consideration various aspects of activities such organizations. For the practical realization of assessment of logistics companies there was proposed Bellinger method, which contains quite transparent procedures. The results obtained from that method are consistent with those carried out by means of other, more complex multi-criteria methods. Also there was presented the problem of selection of weighted factors for the criteria in the context of their impact on the end result of evaluation. It was pointed out that the choice of an appropriate procedure for determining weights depends on the nature of the evaluated problem and form of criteria

Evaluation model of the companies operating within logistic network

In the paper authors presented concept of evaluation of complex systems such as logistic companies which operate in competitive environment. Authors also highlighted the importance of the evaluation problem in operational activity, particularly in the properly prepared procedures to be followed, consisted of several stages adapted to currently conducted research. Properly executed evaluation of companies enables customers to take right decisions on contracting services and stimulate the development of those companies. It should be noted that the proposed algorithmic model of assessment may be particularly useful for assessment of complex logistics systems. Characteristics of the respective phases developed procedure allowed to indicate that it is important to select of appropriate criteria and evaluation methods. It was pointed out that particularly useful for assessing of logistics companies are multi-criteria analysis methods, because they allow to examine objects in a holistic manner, taking into consideration various aspects of activities such organizations. For the practical realization of assessment of logistics companies there was proposed Bellinger method, which contains quite transparent procedures. The results obtained from that method are consistent with those carried out by means of other, more complex multi-criteria methods. Also there was presented the problem of selection of weighted factors for the criteria in the context of their impact on the end result of evaluation. It was pointed out that the choice of an appropriate procedure for determining weights depends on the nature of the evaluated problem and form of criteria

GntR-like SCO3932 Protein Provides a Link between Actinomycete Integrative and Conjugative Elements and Secondary Metabolism

Streptomyces bacteria produce a plethora of secondary metabolites including the majority of medically important antibiotics. The onset of secondary metabolism is correlated with morphological differentiation and controlled by a complex regulatory network involving numerous regulatory proteins. Control over these pathways at the molecular level has a medical and industrial importance. Here we describe a GntR-like DNA binding transcription factor SCO3932, encoded within an actinomycete integrative and conjugative element, which is involved in the secondary metabolite biosynthesis regulation. Affinity chromatography, electrophoresis mobility shift assay, footprinting and chromatin immunoprecipitation experiments revealed, both in vitro and in vivo, SCO3932 binding capability to its own promoter region shared with the neighboring gene SCO3933, as well as promoters of polyketide metabolite genes, such as cpkD, a coelimycin biosynthetic gene, and actII-orf4—an activator of actinorhodin biosynthesis. Increased activity of SCO3932 target promoters, as a result of SCO3932 overproduction, indicates an activatory role of this protein in Streptomyces coelicolor A3(2) metabolite synthesis pathways

Examining evidence of metacognition by preservice secondary mathematics teachers while solving tasks situated in the secondary curriculum

The study's goal was to examine the metacognitive practices and problem solving by preservice secondary mathematics teachers within secondary core content areas. The effort to analyze and describe the processes led to qualitative methods, a multiple case study. Transcripts of problem solving sessions and interviews were coded for the presence of multiple strategies, descriptive language, and use of metacognitive stages. From this coding, detailed accounts of the participants' problem solving were developed and analyzed. Findings revealed conceptual and procedural obstacles existed when participants sought to find an efficient solution to some of the problem solving tasks. Half of the participants struggled with using algebraic symbolization to represent a relationship and all had difficulty describing the variability that existed within sets of data. Both of these skills are integral components of the current secondary curriculum. The analysis also revealed findings concerning the preservice teachers' mathematical practices. A study of the stages of problem solving suggested that the participants' had limited persistence in problem solving and restricted attention to reflection on the processes used. Similarly, an analysis of their language demonstrated incomplete development of concept definition and ineffective use of terminology in a mathematical context. (Published By University of Alabama Libraries

Trends concerning four misconceptions in students' intuitively-based probabilistic reasoning sourced in the heuristic of representativeness

Student difficulty in the study of probability arises in intuitively-based misconceptions derived from heuristics. One such heuristic, the one of note for this research study, is that of representativeness, in which an individual informally assesses the probability of an event based on the degree to which the event is similar to the sample from which it is selected or the degree the event is characterized by the notable features of the system from which it is derived. Four misconceptions were examined in this that study arise from this heuristic: the representativeness misconception, positive and negative recency effects, the distinction between compound and simple events, and the effect of sample size. Furthering the research of Fischbein and Schnarch (1997), this research sought Spearman correlations between frequencies of responses to items testing for the above misconceptions and grade level of students (7th, 9th, or 11th). A significant positive Spearman correlation was found for positive and negative recency effects and a significant negative correlation was found for the effect of sample size. Spearman correlations were also sought between correctness of student responses and perceived self-efficacy in those responses via a five-point Likert scale at each of the three grade levels. Significant positive correlations were found for positive and negative recency effects (all three grades), the distinction between compound events (7th), and the representativeness misconception (7th and 11th); significant negative correlations were found for the effect of sample size (11th) and the distinction between compound and simple events (9th and 11th). (Published By University of Alabama Libraries

The development of the mathematics teaching self efficacy scales for Korean elementary and secondary preservice teachers

The Mathematics Teaching Efficacy Beliefs Instrument (MTEBI), developed in the United States, is one of the most popular scales used in the study of mathematics teaching efficacy. However, the MTEBI might not be trustworthy in other cultures. This study described the development of a new instrument measuring mathematics teaching efficacy beliefs for Korean preservice teachers using Bandura's efficacy theory. In Article One, Korean mathematics teacher education professors' perspectives to the MTEBI were analyzed. This resulted in a revision of the MTEBI in the context of Korean mathematics education, and the recommendation that an instrument should be separated for elementary and for secondary preservice teachers. Article Two described the development of a new instrument, the Mathematics Teaching Self Efficacy Scale (MTSES) for elementary preservice teachers (Form-E). The instrument consists of one single scale with nine items. Marginal reliability was ρ = .8281. Article Three presented the development of the MTSES for secondary preservice teachers (Form-S). This instrument also consists of one single scale with 10 items. Marginal reliability was ρ = .8591. Use of modern item response theory, rather than classical test theory, in the development of an instrument would decrease bias from a local culture. The MTSES Form-E and Form-S was verified by a item response theory model, and thus the MTSES would be a more valid and reliable instrument than the MTEBI. Use of MTSES in an international and cross-cultural study will produce trustworthy and useful information. (Published By University of Alabama Libraries