A new three phase method (SDP method) for the multi-objective vehicle routing problem with simultaneous delvery and pickup (VRPSDP)

Transportation service operators are witnessing a growing demand for bi-directional movement of goods. Given this, the following thesis considers an extension to the vehicle routing problem (VRP) known as the delivery and pickup transportation problem (DPP), where delivery and pickup demands may occupy the same route. The problem is formulated here as the vehicle routing problem with simultaneous delivery and pickup (VRPSDP), which requires the concurrent service of the demands at the customer location. This formulation provides the greatest opportunity for cost savings for both the service provider and recipient. The aims of this research are to propose a new theoretical design to solve the multi-objective VRPSDP, provide software support for the suggested design and validate the method through a set of experiments. A new real-life based multi-objective VRPSDP is studied here, which requires the minimisation of the often conflicting objectives: operated vehicle fleet size, total routing distance and the maximum variation between route distances (workload variation). The former two objectives are commonly encountered in the domain and the latter is introduced here because it is essential for real-life routing problems. The VRPSDP is defined as a hard combinatorial optimisation problem, therefore an approximation method, Simultaneous Delivery and Pickup method (SDPmethod) is proposed to solve it. The SDPmethod consists of three phases. The first phase constructs a set of diverse partial solutions, where one is expected to form part of the near-optimal solution. The second phase determines assignment possibilities for each sub-problem. The third phase solves the sub-problems using a parallel genetic algorithm. The suggested genetic algorithm is improved by the introduction of a set of tools: genetic operator switching mechanism via diversity thresholds, accuracy analysis tool and a new fitness evaluation mechanism. This three phase method is proposed to address the shortcoming that exists in the domain, where an initial solution is built only then to be completely dismantled and redesigned in the optimisation phase. In addition, a new routing heuristic, RouteAlg, is proposed to solve the VRPSDP sub-problem, the travelling salesman problem with simultaneous delivery and pickup (TSPSDP). The experimental studies are conducted using the well known benchmark Salhi and Nagy (1999) test problems, where the SDPmethod and RouteAlg solutions are compared with the prominent works in the VRPSDP domain. The SDPmethod has demonstrated to be an effective method for solving the multi-objective VRPSDP and the RouteAlg for the TSPSDP.

Managing healthcare quality using logical framework analysis

Purpose - The purpose of this paper is to develop an integrated quality management model that identifies problems, suggests solutions, develops a framework for implementation and helps to evaluate dynamically healthcare service performance. Design/methodology/approach - This study used the logical framework analysis (LFA) to improve the performance of healthcare service processes. LFA has three major steps - problems identification, solution derivation, and formation of a planning matrix for implementation. LFA has been applied in a case-study environment to three acute healthcare services (Operating Room utilisation, Accident and Emergency, and Intensive Care) in order to demonstrate its effectiveness. Findings - The paper finds that LFA is an effective method of quality management of hospital-based healthcare services. Research limitations/implications - This study shows LFA application in three service processes in one hospital. This very limited population sample needs to be extended. Practical implications - The proposed model can be implemented in hospital-based healthcare services in order to improve performance. It may also be applied to other services. Originality/value - Quality improvement in healthcare services is a complex and multi-dimensional task. Although various quality management tools are routinely deployed for identifying quality issues in healthcare delivery, they are not without flaws. There is an absence of an integrated approach, which can identify and analyse issues, provide solutions to resolve those issues, develop a project management framework to implement those solutions. This study introduces an integrated and uniform quality management tool for healthcare services. © Emerald Group Publishing Limited.

Integrated approach to healthcare quality management:a case study

Purpose - The purpose of the paper is to develop an integrated quality management model, which identifies problems, suggests solutions, develops a framework for implementation and helps evaluate performance of health care services dynamically. Design/methodology/approach - This paper uses logical framework analysis (LFA), a matrix approach to project planning for managing quality. This has been applied to three acute healthcare services (Operating room utilization, Accident and emergency, and Intensive care) in order to demonstrate its effectiveness. Findings - The paper finds that LFA is an effective method of quality management of hospital-based healthcare services. Research limitations/implications - This paper shows LFA application in three service processes in one hospital. However, ideally this is required to be tested in several hospitals and other services as well. Practical implications - In the paper the proposed model can be practised in hospital-based healthcare services for improving performance. Originality/value - The paper shows that quality improvement in healthcare services is a complex and multi-dimensional task. Although various quality management tools are routinely deployed for identifying quality issues in health care delivery and corrective measures are taken for superior performance, there is an absence of an integrated approach, which can identify and analyze issues, provide solutions to resolve those issues, develop a project management framework (planning, monitoring, and evaluating) to implement those solutions in order to improve process performance. This study introduces an integrated and uniform quality management tool. It integrates operations with organizational strategies. © Emerald Group Publishing Limited.

Prepaid monetary incentives on mail survey response

Increasing mail survey response using monetary incentives is a proven, but not always cost-effective, method in every population. This paper tackles the questions of whether it is worth using monetary incentives and the size of the inducement by testing a regression model of the impact of prepaid monetary incentives on response rates in consumer and organizational mail surveys. The results support their use and show that the inducement value makes a significant impact on the effect size. Importantly, no significant differences were found between consumer and organizational populations.

The optimum prepaid monetary incentives for mail surveys

Increasing mail-survey response using monetary incentives is a proven, but not always cost-effective method in every population. This paper tackles the questions of whether it is worth using monetary incentives and the size of the inducement by testing a logit model of the impact of prepaid monetary incentives on response rates in consumer and organizational mail surveys. The results support their use and show that the inducement value makes a significant impact on the effect size. Importantly, no significant differences were found between consumer and organizational populations. A cost-benefit model is developed to estimate the optimum incentive when attempting to minimize overall survey costs for a given sample size. © 2006 Operational Research Society Ltd. All rights reserved.

The influence of age on the pattern and flash visual evoked field

We have investigated the effect of ageing on the visual system using the relatively new technique of magentoencephalography (MEG). This technique measures the magnetic signals produced by the visual system using a SQUID magnetometer. The magnetic visual evoked field (VEF) was measured over the occipital cortex to pattern and flash stimuli in 86 normal subjects aged 15 - 86 years. Factors that influenced subject defocussing or defixating the stimulus or selective attention were controlled as far as possible. The latency of the major positive component to the pattern reversal stimulus (P100M) increased with age particularly after the age of 55 years while the amplitude of the P100M decreased over the life span. The latency of the major flash component (P2M) increased much more slowly with age, while its amplitude decreased in only a proportion of elderly subjects. Changes in the P100M with age may reflect senile changes in the eye and optic nerve, e.g. senile miosis or degenerative changes in the retina. The P2M may be more susceptible to senile changes in the retina. The data suggest that the spatial frequency channels deteriorate more rapidly with age than the luminance channels and that MEG may be an effective method of studying ageing in the visual system.

Prepaid monetary incentives on mail survey response

Increasing mail survey response using monetary incentives is a proven, but not always cost-effective, method in every population. This paper tackles the questions of whether it is worth using monetary incentives and the size of the inducement by testing a regression model of the impact of prepaid monetary incentives on response rates in consumer and organizational mail surveys. The results support their use and show that the inducement value makes a significant impact on the effect size. Importantly, no significant differences were found between consumer and organizational populations.

Mechanisms of convective drying in thick beds of solids

The literature on heat and mass transfer mechanisms in the convective drying of thick beds of solids has been critically reviewed. Related mathematical models of heat transfer are also considered. Experimental and theoretical studies were made of the temperature distribution within beds, and of drying rates, with various materials undergoing convective drying. The experimental work covered thick beds of hygroscopic and non-hygroscopic materials (glass beads of different diameters, polystyrene pellets, activated alumina and wood powder) at air temperatures of 54°C to 84°C. Tests were carried out in a laboratory drying apparatus comprising a wind tunnel through which the air, of controlled temperature and humidity, was passed over a sample suspended from a balance. Thermocouples were inserted at different depths within the sample bed. The temperature distribution profiles for both hygroscopic and non-hygroscopic beds exhibited a clear difference between the temperatures at the surface and bottom during the constant rate period. An effective method was introduced for predicting the critical moisture content. During the falling rate the profiles showed the existence of a receding evaporation plane; this divided the system into a hotter dry zone in the upper section and a wet zone near the bottom. A graphical procedure was established to predict accurately the position of the receding evaporation front at any time. A new mathematical model, based on the receding evaporation front phenomenon, was proposed to predict temperature distributions throughout a bed during drying. Good agreement was obtained when the model was validated by comparing its predictions with experimental data. The model was also able to predict the duration of each drying stage. In experiments using sample trays of different diameters, the drying rate was found to increase with a decrease in the effective length of the bed surface. During the constant rate period with trays of a small effective length, i.e. less than 0.08 m, an 'inversion' in temperature distribution occurred in the bed; the bottom temperature increased and became greater than that of the surface. Experimental measurements were verified in several ways to ensure this phenomenon was real. Theoretical explanations are given for both the effective length and temperature inversion phenomena.

An evaluation of pharmacy education and pre-registration training

This thesis covers two major aspects of pharmacy education; undergraduate education and pre-registration training. A cohort of pharmacy graduates were surveyed over a period of four years, on issues related to undergraduate education, pre-registration training and continuing education. These graduates were the first-ever to sit the pre-registration examination. In addition, the opinions of pre-registration tutors were obtained on pre-registration training, during the year that competence-based assessment was introduced. It was concluded that although the undergraduate course provided a broad base of knowledge suitable for graduates in all branches of pharmacy, several issues were identified which would require attention in future developments of the course. These were: 1. the strong support for the expansion of clinical, social and practice-based teaching. 2. the strong support to retain the scientific content to the same extent as in the three-year course. 3. a greater use of problem-based learning methods. The graduates supported the provision of a pre-registration continuing education course to help prepare for the examination and in areas inadequately covered in the undergraduate course. There was also support for the introduction of some form of split branch training. There was no strong evidence to suggest that the training had been an application of undergraduate education. In general, competence-based training was well regarded by tutors as an appropriate and effective method of skill assessment. However, community tutors felt it was difficult to carry out effectively due to day-to-day time constraints. The assistant tutors in hospital pharmacy were found to have a very important role in provision of training, and should be adequately trained and supported. The study recommends the introduction of uniform training and a quality assurance mechanism for all tutors and assistants undertaking this role.

An evaluative analysis of the practice of teamwork in Health and Personal Social Services

This report describes the practice of teamwork as expressed in case conferences for care of the elderly and evaluates the effectiveness of case conferences in their contribution to care. The study involved the observation of more than two hundred case conferences in sixteen locations throughout the West Midlands, in which one thousand seven hundred and three participants were involved. Related investigation of service outcomes involved an additional ninety six patients who were interviewed in their homes. The pu`pose of the study was to determine whether the practice of teamwork and decision-making in case conferences is a productive and cost effective method of working. Preliminary exploration revealed the extent to which the team approach is part of the organisational culture and which, it is asserted, serves to perpetuate the mythical value of team working. The study has demonstrated an active subscription to the case conference approach, yet has revealed many weaknesses, not least of which is clear evidence that certain team members are inhibited in their contribution. Further, that the decisional process in case conferences has little consequence to care outcome. Where outcomes are examined there is evidence of service inadequacy. This work presents a challenge to professionals to confront their working practices with honesty and with vision, in the quest for the best and most cost effective service to patients.

Factors affecting the accommodative response to sustained visual tasks

In the absence of adequate visual stimulation accommodation adopts an intermediate resting position, appropriately termed tonic accommodation (TA). A period of sustained fixation can modify the tonic resting position, and indicate the adaptation properties of TA. This thesis investigates various factors contributing to the accommodative response during sustained visual tasks, in particular the adaptation of TA. Objective infra-red optometry was chosen as the most effective method of measurement of accommodation. This technique was compared with other methods of measuring TA and the results found to be well correlated. The inhibitory sympathetic input to the ciliary muscle provides the facility to attenuate the magnitude and duration of adaptive changes in TA. This facility is, however, restricted to those individuals having relatively high levels of pre-task TA. Furthermore, the facility is augmented by substantial levels of concurrent parasympathetic activity. The imposition of mental effort can induce concurrent changes in TA which are predominantly positive and largely the result of an increase in parasympathetic innervation of the ciliary muscle although there is some evidence for sympathetic attentuation at higher levels of TA. In emmetropes sympathetic inhibition can modify the effect of mental effort on the steady-state accommodative response at near. Late-onset myopes (onset after the age of 15 years) have significantlylower values of TA then emmetropes. Similarly, late-onset myopes show lower values of steady-state accommodative response for nearstimuli. The imposition of mental effort induces concurrent increases in TA and steady-state accommodative response in the myopic group which are significantly greater than those for emmetropes. Estimates of TA made under bright empty-field conditions are well correlated with those made under darkroom conditions. The method by which the accommodative loop is opened has no significant effect on the magnitude and duration of post-task shifts in TA induced by a near vision task. Significant differences in the post-task shifts in TA induced by a near vision task exist between emmetropes and late-onset myopes, the post-task shifts being more sustained for the myopic group.

Investigation into visual defects attributed to Vigabatrin

Vigabatrin (VGB) is a transaminase inhibitor that elicits its anitepileptic effect by increasing GABA concentrations in the brain and retina. - Assess whether certain factors predispose patients to develop severe visual field loss. - Develop a sensitive algorithm for investigating the progression of visual field loss. - Determine the most sensitive clinical regimen for diagnosing VGB-attributed visual field loss. - Investigate whether the reports of central retinal sparing are accurate. The investigations have resulted in a number of significant findings: - The anatomical evidence in combination with the pattern of visual field loss suggests that the damage induced by VGB therapy occurs at retinal level, and is most likely a toxic effect. - The quantitative algorithm, designed within the course of this investigation, provided increased sensitivity in determining the severity of visual field loss. - Maximum VGB dose predisposes patients to develop severe visual field loss. - The SITA Standard algorithm was found to be as sensitive and significantly faster, in diagnosing visual field defects attributed to VGB, when compared to the Full Threshold algorithm. The Full Threshold was found to be the most repeatable between visits. - The normal SWAP 10-2 database provided an effective method of differentiating SWAP defects. - SWAP, FDT and the mfERG have increased sensitivity in detecting visual field loss attributed to VGB. The pattern of visual field loss from these investigations suggests that VGB produces a diffuse effect across the retina including subtle central abnormalities and more severe peripheral defects. - Abnormalities detected using the mfERG have suggested that VGB adversely affects the photoreceptors Müller, amacrine and ganglion cells in the retina. An urgent review of the manufacturers recommended maximum dose for VGB is required.

Efficacy and toxicity of biocides used in handling sterile pharmaceuticals

This thesis has sought to investigate disinfection agents and procedures which may provide sanitisation against bacterial spores. A hard-surface disinfection test method was designed to ascertain which combinations of biocide and application method were most effective against bacterial spores. A combination of spraying and wiping was the most effective method of disinfection against Bacillus spores, with wiping found to play a key role in spore removal. The most efficacious of the biocides investigated was the 6% hydrogen peroxide. Vaporised Hydrogen Peroxide (VHP) gassing was more effective than traditional disinfection. In addition to efficacy, the toxic potential of the biocides to human airway epithelial cells in vitro was evaluated. Toxicity against human bronchial and nasal epithelial cells was assessed by determining cell viability, inflammatory status, protein oxidation and epithelial cell layer integrity. In addition the cell death mechanism following biocide exposure was investigated. There was a decrease in viable cells following exposure to all biocides when applied at practical concentrations. Almost all of the biocides tested elicited a pro-inflammatory response from the cells as measured by IL-8 production. All biocides increased protein oxidation as measured by thiol and carbonyl levels. Measurement of transepithelial electrical resistance and paracellular permeability indicated biocide-dependent decrease in epithelial cell barrier function. The cellular response was biased towards necrotic rather than apoptotic death. The use of biocides, although efficacious to some effects against Bacillus spores, will require careful monitoring for adverse health effects on personnel.

Delivering optometric care in the UK

Optometrists play an important part in delivering eye care in the United Kingdom; however opportunities for practitioners to extend their role through co-management of patients with ophthalmologists vary across the country. Devolution in Scotland and Wales has led to greater emphasis on community based care in these regions. This thesis reviews the current situation and, by examining ophthalmic outpatient clinic data, discusses further opportunities to reduce demands on secondary care and the cost savings that can be made. To assess whether the profession is currently in a position to adopt an extended clinical role, changes in the availability of optometric instrumentation are assessed over a two year period. An increased prevalence of fundus cameras and contact tonometers places optometrists in a good position to take on further responsibilities in glaucoma management, however future investment could be impacted by the current economic climate as value for money became increasingly important to practitioners looking to purchase equipment. Methods of training optometrists in the necessary skills to utilise new technology to extend their role are evaluated in terms of both learning and cost effectiveness. Interactive distance learning is proposed as a convenient and effective method to deliver continuing professional development. Any changes to optometric practice must take account of the need for a sustainable business and the importance of attracting and retaining patients. The views of patients are assessed through a validated service quality questionnaire, SERVQUAL. The questionnaire is found to be valid for use in an optometry setting. Patients have a generally positive view of the service quality they receive from their optical practice and consider the intangible aspects, in particular responsiveness and empathy, most important. Optometrists are well placed to increase their role in patient management; however a viable business model must exist to enable investment in instrumentation and training.

Graphene layers produced from carbon nanotubes by frication

Graphene layers have been produced from multi-walled carbon nanotube (MWCNT) bulk materials by friction when polished on ground-glass, offering a novel and effective method to produce graphene layers, which, more importantly, could be transferred to other substrates by rubbing. Field emission scanning electron microscopy, Raman spectroscopy, atomic force microscopy, transmission electron microscopy and selected area electron diffraction confirmed the formation of graphene layers. They were thought to be peeled away from the MWCNT walls due to friction. The reflection spectra showed that absorption of as-produced graphene layers decreased with wavelength in the range of 250–400 nm, compared to the MWCNT bulk material having strong absorption at 350 nm. Nanoscratch test was used to determine the mechanical properties of graphene films, suggesting the tolerance of as-produced graphene film to flaws introduced by scratch.