Dynamic lot sizing and tool management in automated manufacturing systems

Cataloged from PDF version of article.The overall aim of this study is to show that there is a critical interface between the lot sizing and tool management decisions, and these two problems cannot be viewed in isolation. We propose "ve alternative algorithms to solve lot sizing, tool allocation and machining conditions optimization problems simultaneously. The "rst algorithm is an exact algorithm which "nds the global optimum solution, and the others are heuristics equipped with a look-ahead mechanism to guarantee at least local optimality. The computational results indicate that the amount of improvement is statistically signi"cant for a set of randomly generated problems. The magnitude of cost savings is dependent on the system parameters

Epiphytic bryozoan community of Posidonia oceanica (L.) Delile leaves in two different meadows at disturbed and control locations

The impact of fish farming activities on Posidonia oceanica meadows in the Aegean Sea have been detected by using bryozoan epiphytes as indicators of disturbance. Samples were collected by SCUBA diving in September 2004 for comparing assemblages between disturbed (I1:0-5 m; I2:5-10 m and I3:10-15 m) and control meadows (C1:0-5 m; C2:5-10 m and C3:10-15 m) located at different depths. Regarding to mean percentage cover of bryozoans, significant differences were found between stations, leaf sides, depths and their interactions (p<0.05). Bryozoan species were colonized densely on back side of the adult leaves. Bantariella verticillata, Alcyonidium sp., Aetea truncata, Chorizopora brongniartii, Fenestrulina joannae were frequently observed species on P. oceanica leaves. B. verticillata showed statistically significant side and station differences while other species showed only significant side differences. Moreover, the mean coverage of Aetea truncata showed neither station nor side variations. B. verticillata could be evaluated as an appropriate key species for environmental changes. In the impacted meadow, higher mean coverage values of the species were particularly determined on front side of the leaves. These results suggest that characteristics of localities, leaf sides and leaf parts can be responsible factors on coverage value of epiphytic bryozoan species

Psychiatric disorders among war-abducted and non-abducted adolescents in Gulu district, Uganda: a comparative study

Objective:We aimed to assess the nature and patterns of psychiatric disorders among adolescents who had been war-abducted in the war in northern Uganda, compared to non-abducted adolescents living in Gulu district, Uganda.Method: A cros sectional study that used an unmatched case-control design compared 82 abducted and 71 non-abducted adolescents for scores on measures of psychological distress and for selected psychiatric diagnoses using the Strength and Difficulties Questionnaire (SDQ) and the Mini International Neural-Psychiatric Interview for Children and Adolescents English version 2.0 (M.I.N.I-KID). Results: More than 90% of adolescents reported exposure to severe trauma, either through direct or indirect experiences. Significantly more war abducted adolescents reported PTSD (26.8%v.12.7%) (p=0.03) major depression (19.5%v.4.2%) (p=0.004), and generalised anxiety disorder (13.4v.4.2%) (p=0.049) than non abducted adolescents. By contrast, non-abducted adolescents reported more past suicidality (p=0.004, &#967;2=8.2) than adolescents who were abducted. However, despite high rates of psychiatric disorder, these adolescents had good psychosocial adjustment. Conclusion: Adolescents in war affected areas whether warabducted or not have varied and clinically significant emotional responses to different kinds of traumatic exposure. In a war-affected area, the development of a sustainable service for adolescents that tries to address the full range of mental health problems may be more appropriate than a psychological trauma service that focuses on one diagnosis.African Journal of Psychiatry Vol. 10 (4) 2007: pp. 225-23

Principles of practice parameters for the treatment of sleep disordered breathing in the elderly and frail elderly: the consensus of the International Geriatric Sleep Medicine Task Force

Sleep disordered breathing (SDB) is a leading cause of morbidity worldwide. Its prevalence increases with age. Due to the demographic changes in industrial societies, pulmonologists and sleep physicians are confronted with a rapidly growing number of elderly SDB patients. For many physicians, it remains unclear how current guidelines for SDB management apply to elderly and frail elderly patients. The goal of this consensus statement is to provide guidance based on published evidence for SDB treatment in this specific patient group. Clinicians and researchers with expertise in geriatric sleep medicine representing several countries were invited to participate in a task force. A literature search of PubMed from the past 12 years and a systematic review of evidence of studies deemed relevant was performed. Recommendations for treatment management of elderly and frail elderly SDB patients based on published evidence were formulated via discussion and consensus. In the last 12 years, there have been surprisingly few studies examining treatment of SDB in older adults and even fewer in frail older adults. Studies that have been conducted on the management of SDB in the older patient population were rarely stratified for age. Studies in SDB treatment that did include age stratification mainly focused on middle-aged and younger patient groups. Based on the evidence that is available, this consensus statement highlights the treatment forms that can be recommended for elderly SDB patients and encourages treatment of SDB in this large patient group

Dynamic lot sizing and tool management in automated manufacturing systems

The overall aim of this study is to show that there is a critical interface between the lot sizing and tool management decisions, and these two problems cannot be viewed in isolation. We propose five alternative algorithms to solve lot sizing, tool allocation and machining conditions optimization problems simultaneously. The first algorithm is an exact algorithm which finds the global optimum solution, and the others are heuristics equipped with a look-ahead mechanism to guarantee at least local optimality. The computational results indicate that the amount of improvement is statistically significant for a set of randomly generated problems. The magnitude of cost savings is dependent on the system parameters. In most of the studies on tool management, lot sizes are taken as a predetermined input while deciding on tool allocations and machining parameters. This might create empty feasible solution spaces and otherwise unnecessarily limit the number of alternatives possible for the tool management problem. In this study, we consider the integration of lot sizing and tool management problems ot minimize total production cost for multiple periods under dynamic demand. By integrating these decisions we not only improve the overall solution, but also prevent any infeasibility that might occur for the tool management problem due to decisions made at the lot sizing level. © 2002 Elsevier Science Ltd. All rights reserved

Instructional Supervision and the Pedagogical Practices of Secondary School Teachers in Uganda

This paper looks at the effect of instructional supervision by school authorities on the pedagogical practices of teachers in public secondary schools in Uganda. To date, research into this field in the country has focused more on the technicalities of supervision rather than on how the teachers have been responding to it. The study employed a descriptive cross-sectional survey design, in which both quantitative and qualitative methods of data collection and analysis were applied. Study respondents included 934 teachers randomly selected from 95 public secondary schools, 76 head teachers, and two officials from the Directorate of Education Standards of the Ministry of Education and Sports. Ordered logistic regression technique was used to establish the effect of instructional supervision on the pedagogical practices of teachers. Findings of the study revealed that both classroom observation (odd ratio=4.1; p=0.000&lt;0.05) and portfolio supervision (odd ratio=2.3; p=0.000&lt;0.05) have statistically significant effect on the pedagogical practices of teachers in public secondary schools in Uganda. Furthermore, the study established that school authorities were inadequately carrying out instructional supervision, thereby leaving teachers to employ ineffective pedagogical practices. The study concluded that teachers’ pedagogical practices are dependent on the manner in which they are supervised, other factor notwithstanding. Therefore, in order to augment the pedagogical practices of teachers, school inspection by the Directorate of Education Standards should be increased and regular in-service training needs to be provided to head teachers as well as subject heads on how to conduct classroom observations and portfolio supervision in schools. Keywords: Instructional supervision, classroom observations, portfolio supervision, pedagogical practice

Written and Non-Written Communication Methods as Correlates of Employee Performance: A Study of Academic Staff of Primary Teachers’ Colleges in Central Uganda

This study delved into how written and non-written communication methods are correlated with the performance of the academic staff of Primary Teachers’ Colleges (PTCs) in Central Uganda.  The study was prompted by reportedly the deteriorating performance of the academic staff of most PTCs in the country despite government’s efforts to train and motivate them. The study employed a correlational cross-sectional survey design where both quantitative and qualitative data were collected from a total of 120 respondents comprised of 5 Principals, 7 Deputy Principals, 13 Heads of Department and 95 members of the Academic Staff using questionnaire survey and interview methods. The data were analyzed with the use of descriptive and inferential statistical techniques as well as content analysis method. Study results revealed that non-written communication methods generally have a statistically weak correlation (r=.380, p=.146) with the performance of the academic staff while written communication methods – whether personally or impersonally addressed - revealed a statistically significant correlation (r=.912, p=.000) with the performance of the academic staff. The researchers thus concluded that the kind of communication methods that managers/administrators employ on their staff have a bearing on how their staff perform their jobs. Thus, it was recommended that colleges’ administrators as well as those concerned with communicating with the academic staff of PTCs should carefully select from the array of available communication methods those that have significant positive correlations with the performance of the staff in order to enhance their job performance as well as that of the entire institution. Keywords: Communication methods, Academic staff, Performance, Primary teachers’ colleges

Epiphytic bryozoan community of Posidonia oceanica (L.) Delile leaves in two different meadows at disturbed and control locations

The impact of fish farming activities on Posidonia oceanica meadows in the Aegean Sea have been detected by using bryozoan epiphytes as indicators of disturbance. Samples were collected by SCUBA diving in September 2004 for comparing assemblages between disturbed (I1:0-5 m; I2:5-10 m and I3:10-15 m) and control meadows (C1:0-5 m; C2:5-10 m and C3:10-15 m) located at different depths. Regarding to mean percentage cover of bryozoans, significant differences were found between stations, leaf sides, depths and their interactions (p<0.05). Bryozoan species were colonized densely on back side of the adult leaves. Bantariella verticillata, Alcyonidium sp., Aetea truncata, Chorizopora brongniartii, Fenestrulina joannae were frequently observed species on P. oceanica leaves. B. verticillata showed statistically significant side and station differences while other species showed only significant side differences. Moreover, the mean coverage of Aetea truncata showed neither station nor side variations. B. verticillata could be evaluated as an appropriate key species for environmental changes. In the impacted meadow, higher mean coverage values of the species were particularly determined on front side of the leaves. These results suggest that characteristics of localities, leaf sides and leaf parts can be responsible factors on coverage value of epiphytic bryozoan species