ACTH is secreted in a pulsatile manner, so it is unclear if increased ACTH secretion occurs in depression and if there are changes in the pulsatile components of ACTH secretion. Ten minutes sampling for ACTH was performed for 24 hr in 25 premenopausal depressed women whose age and menstrual cycle day matched control women found in pulsatile components of ACTH secretion between patients and matched controls. This paper is applied to Optimal time T*, Minimal Repair δ and Random Lead Time g to minimize the ACTH level
Increased cortisol level is a renowned finding in patients even it is present in only 25- 30% of subjects with major depression. However cortisol is secreted in a pulsatile manner ten minute sampling for cortisol is performed for 24 hr in 25 premenopausal depressed women whose age and menstrual cycle day matched control women. Pulse analyses revealed similar number of secretory bursts in patients and control. This paper is applied to Optimal time T*, Minimal Repair δ and Random Lead Time g to mi minimize the cortisol level
The potential of post-tensioned self-centering moment-resisting frames (SC-MRFs) and viscous dampers to reduce the economic seismic losses in steel buildings is evaluated. The evaluation is based on a prototype steel building designed using four different seismic- resistant frames: (a) conventional moment resisting frames (MRFs); (b) MRFs with viscous dampers; (c) SC-MRFs; or (d) SC-MRFs with viscous dampers. All frames are designed according to Eurocode 8, and have the same column/beam cross-sections and similar periods of vibration. Viscous dampers are designed to reduce the peak story drift under the design basis earthquake (DBE) from 1.8% to 1.2%. Losses are estimated by developing vulnerability functions according to the FEMA P-58 methodology, which considers uncertainties in earthquake ground motion, structural response, and repair costs. Both the probability of collapse and the probability of demolition due to excessive residual story drifts are taken into account. Incremental dynamic analyses are conducted using models capable to simulate all limit states up to collapse. A parametric study on the effect of the residual story drift threshold beyond which is less expensive to rebuild a structure than to repair is also conducted. It is shown that viscous dampers are more effective than post-tensioning for seismic intensities equal or lower than the maximum considered earthquake (MCE). Post- tensioning is effective in reducing repair costs only for seismic intensities higher than the DBE. The paper also highlights the effectiveness of combining post-tensioning and supplemental viscous damping by showing that the SC-MRF with viscous dampers achieves significant repair cost reductions compared to the conventional MRF.
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It is a common practice to decide the pavement maintenance based on mere observations and personal judgment and experience. As the observations are subjective, to overcome this limitation, a scientific approach for defining condition state of pavement with respect to age of pavement and its maintenance cost is developed by the authors. Typical construction procedure used by Public Works Department of Maharashtra state is considered. Average pavement life of bituminous rural road is observed as 14 years and hence the entire life span is divided into 7 equal periods i.e. regularly at 2 years. Maintenance cost for such several pavement stretches in single lane rural road network is calculated for each of 2 year span of observation. Average cost of each condition state is then identified from this data. Based on this observations condition state pavements are defined in to 7 categories – from 7 (new condition state) to 1 (poor condition needing immediate total rehabilitation). For rate analysis, District Schedule Rates of Public Work Department, Pune 2012-13 is referred. Table 1 shows the different condition state descriptions of the pavements and corresponding repair cost required for rehabilitation / renovation up to new condition state.
This research was initiated with the idea of developing a methodology/framework to be able to assess the life-cycle cost/earning of production and maintenance/repair with respect to the structural optimisation variables, mainly scantlings and its derivative lightweight, to be used during the conceptual ship design stage. It is a fact that changes in scantlings might have a big cost impact on production and maintenance/repair because of increasing/decreasing steel weight. In general, lighter weight and smaller plate thickness may possibly mean more extensive steel replacement unless a proper hull maintenance strategy is adopted. This can also lead to longer dry-docking times and thereby increasing costs in terms of the cost of dry- docking and the cost of the ship being unavailable for use. However, heavier lightship also means heavier displacement and hence a higher fuel cost or smaller deadweight capacity, and hence lower operational income. It is important to know and assess this impact at the earliest phase of a ship’s life-cycle for many reasons such as evaluation and comparison of alternative designs, identification of main cost drivers, and maintenance planning etc. Assessing production cost is a straightforward calculation and a well-studied area in literature [Ross 2004; Ross and Aasen 2005; Bole 2006, 2007; Miroyannis 2006; Keulen et al 2007]. However, assessing the maintenance/repair cost of a ship during the design stage requires a life-cycle prediction in terms of the amount of steel to be replaced and the amount of time the ship is unavailable in the drydock. Therefore, history and past data relating to a ship type become vital and critical.
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that when π is very high, then low reorder point helps to reduce deteriorating cost. On the other hand, π has small impact on the production up time. Production up time is changing (decreasing) slowly due to increase in π . However, this response of τ indicates that high value of π leads to a low volume of production, and as a result, small generation of deteriorated items. The expected total cost per unit increases as M is increased, it means when m/c repair cost is increased then it helps to increase the total cost per year. It is noted that M has no influence on the reorder point & production up time. Production up time & reorder point do not change with the increase in repair cost. From Figs. (14-16) it can also be seen that total cost per unit decreases as P is increased; it means when production rate is increased then it helps to decrease production run time, and as a result, expected total cost is decreased. When production rate is increased, the gap between production & demand is also increased as demand rate is fixed, and consequently, volume of deterioration is also increased. That’s why in order to minimize this deteriorating quantity as many as possible; reorder point is moving towards low value with the increase in production rate. Moreover, high rate of production also helps to minimize the probability of shortage as demand rate is still remaining same. Considering this matter, the low reorder point is more appropriate.
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workshop and brainstorming sessions, numerous ideas and suggestions to improve PM performances were presented. Then, these ideas and suggestions were analyzed and prioritized to execute one by one. Finally, the accepted ideas were executed. To assure the effectiveness of VE, the PM system was analyzedwith respect to the two indexes, namely, cost reduction and service improvement. In the third phase, using the results of this research, the possibility of implementing VE technique to improve the PM systems of civil engineering was identified. Figure 1 schematically illustrates these three phases.
Although a number of respondents agreed tenant behaviour should be considered as a factor to influence how long the organisation takes to respond to repair complaints, the vast majority however disagree and strongly disagree with the question. Although there were no additional comments provided, one can assume that they disagree with this question as it clashed with the notions of CSR regardless of their behaviour. Literature suggested that having good CSR will help them gain good customer satisfaction and loyalty (Lee et al., 2016). If BH treat customers differently due to their behaviour, they will lose the loyalty of their customers who may seek to move to a different social housing company, which will be detrimental to the company as the company will lose business and profits.
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Earthquakes are among those natural hazards which may lead to disruption in the function of arte- rial traffic routes. Road networks are particularly vulnerable, due to their geographical dispersion, extensive functions and structural reliance on favourable geophysical conditions. Traffic function- ality after a natural disaster and the repair/rehabilitation cost of roads are crucial considerations in planning the best priority recovery scenario. In the current paper, the primary focus is placed on the method for evaluating the costs of damage to the roadway network following an earthquake. Bridges, pavements, tunnels and base layers are assumed to be the main elements of a roadway structure. Through this approach, the level of damage can be specified for each component of the roadway. The repair/rehabilitation cost pattern can then be generated according to the level of damage, and the entire reconstruction costs can be calculated according to the total damaged surface area of each route. Finally, the total damage cost of roadways can be provided by consider- ing the likely duration of the rehabilitation period, and determining the performance reduction in traffic flow caused by the damaged components. Secondly this paper demonstrates a method of measuring roadways’ functional performance. This method, based on path dividing and consid- eration of the attachment of sections leads to more precise feedback on roadways’ functionality. This is calculated by computing the width of sections in a route that remain undamaged and which retain the ability to sustain traffic flow. In this way, traffic flow and the linkage of sections can be determined as functions of road capacity.
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Methods: This article is based on the Drummond and O’Brien methodology, which specifically determines the content of direct and indirect costs in health services. The costs of operations during the period 2010–2014 were specified for a total of 746 patients. The cost details are described for four patients who represent the use of different types of medical devices. The procedure was a laparoscopic surgery in all cases.
Netherlands, demand detailed information concerning the maintenance of Thales equipment. They want to know exactly where to repair all the components that are subject to failure, where to hold spare parts in the repair network and what kind of equipment is needed to perform the repair actions. The MIL-STD-1388-1A is the general accepted standard of what has to be included in a maintenance concept. If customers request maintenance information in the procurement phase, the department Logistic Engineering roughly indicates which repair activities and how many spare parts are needed. The indicated policies result in a maintenance budget that a customer can use to estimate the total life cycle costs of a system. A maintenance budget contains all the costs that are related to the upkeep of a system. Life cycle costs are incurred with the development, production, use, maintenance and disposal of a product. If customers decide to buy Thales radar equipment they can request a detailed maintenance analysis. Such an analysis consists of well-founded repair and stock allocation decisions. A detailed analysis is done at the Thales LE department by a logistic engineer and can take up to approximately 400 hours for a single system. The customer has to pay additionally for such a detailed analysis. In general, customers carry out the maintenance that is needed to maintain the Thales radar equipment. Customers hold spare parts, procure test equipment, and open repair facilities in the repair network. More and more customers, such as the United Kingdom, request Thales to provide them with a service contract where Thales is responsible for the repair and the holding of spare parts. Denmark has contracted Thales for the delivery of spare parts within five days upon system failure. Thales expects that this trend will continue and considers the possibility of offering integrated service contracts in which Thales is responsible for the availability of the system that is sold to the customer. Since the selling of services is generally more profitable than the selling of products (Deloitte, 2006; Murthy et al., 2004; Olivia and Kallenberg, 2003), the generation of cost effective maintenance policies are, especially in this case, of great interest to Thales. Since not all customers require a LORA and the sale of capital goods is only limited to a few systems a year, a LORA is required only a limited number of times a year. The department LE is responsible for performing a LORA.
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experts have discussed the problems related common cause failure  with human error [1, 2, 11]. In the past reliability researchers [3, 4, 5] analysed the reliability performance of redundant repairable system including industrial system like paper plant with minimum repair and degraded failure. Though, the authors [8, 9, 10] have done good work on determining the reliability characteristics such as availability, M.T.T.F., predictable cost etc. with different types of failures/repairs but they did not consider one of the important aspects that the system can be analyzed with two repairmen having different skills which seems to be possible in many engineering systems. When this possibility exists, reliability evaluation of the system can be done with the help of copula .
For instance, in maintenance systems at industrial centers, Inputs are the cars that are likely to deteriorate and limited in numbers. Now we consider a problem with limited population of demanders for example, the population of applicants is equal to m and probabilities of events will be the function of past behavior. A typical application for this model is car servicing where the demanders population are the cars or parts of cars that have become damaged and require repair. Repairmen are the service providers.
thermonuclear system. Recently Lado et al.  analyzed two subsystems connected in a series configuration and operated by a human operator. In this study, they concluded that copula repair is more reliable compared to general repair. Also, Babu et al.  studied a δ-shock maintenance model for a deteriorating system with an imperfect delayed repair under partial process. In addition, Singh and Poonia  studied two units parallel system with correlated lifetime under inspection using regenerative point technique.
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Calculations for wind turbines located at North Sea sites for which wave data are available indicate that annual down-times are dominated by repairs to the blades, generator and gearbox. These are not necessarily the subsystems with the highest failure rates but those requiring long repair windows and whose repairs currently require large crane vessels, the use of which is severely restricted by sea-state. The greatest influence on down-time and availability is found to come from changes in the access conditions for repairs, by reducing reliance on ‘sensitive’ vessels, by reducing repair time at the turbine and by reducing vessels’ sensitivity to sea-state.
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The proposed mathematical model minimizes the total cost of the closed-loop spare parts inventory-location; the first two terms of objective function depicts the fixed location cost of DCs and RCs. The next fourth line shows the total cost of the forward supply chain, which is contained the delivery cost of spare parts to the operational bases from, in which DCs are assigned to them, the delivery cost of sending the failed items to the RCs from operational bases, total expected inventory costs that purpose a, g and F are related to the location of each DC and the last term of forward supply chain represent the total expected safety stock inventory cost based on risk pooling of the uncertainty of demand. Safety stock is commonly set to be proportional to standard deviation of the demand occurring throughout the lead time. Reducing in variability of demand can be achieved by reducing in safety stock. The aggregating demand from all bases is smaller than the sum of the variances demand of those bases. Therefore, the amount of safety stock which is needed for pooled demand is usually less than the sum of safety stock of each base’s demand. As a result, using the risk pooling strategy
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On the other hand, failure of transformers in distribution substations causes customer’s outages and cost. Recent cost depends on customer type and outage duration. In this situation, time for recovering of failed unit, by repairing and purchasing a new unit may last several months that it depends on the type of failure. Outage durations may be reduced considerably by using of spare transformers. So the number of spare transformers must be selected to supply sufficient transformers in the stock room with high reliability. If the numbers of spare transformers are increased excessively, cost of purchasing and maintenance will increase. On the other hand, whatever, number of spares are increased, total cost will increase and if the number of spares be less than a critical value, we must pay much costs for customer’s outages.
The correct and economical use of machinery is one of the most important aims of the forest ma- chinery management. Both the purchase and utili- zation of the machinery involve huge investments in forest logging. Equipment will eventually wear out, so the need for reliable and dependable operations should compel forestry contractors to follow the proper equipment replacement strategies (Cantú, LeBel 2010). In the replacement strategies, the pri- mary function of contractors is to replace the right equipment at the right time and with the lowest overall cost (Fan et al. 2011). The replacement is performed by the different goals when one of the most important goals is the economic goal: reduc- ing costs and increasing revenues. In fact, based on the desire to minimize costs, as soon as a ma-
The article investigates a generic framework to estimate maintenance costs attributed to the No Fault Found (NFF) phenomenon. Such overhead costs are particularly difﬁcult to quantify due to potentially serviceable equipment being returned for repair. Other factors, such as a reduction in the availability of the system, compromising reliability of high value assets, and logistical factors, can all contribute to the cost of resolving an unknown fault. Here we apply the soft systems methodology to capture the critical cost drivers of NFF across the supply chain and build a framework to estimate the cost of NFF. We use a multi-method design including an online survey, workshops and semi-structured interviews to study NFF related cost practices based on information from 12 key participants across 7 UK organisations. The study identi ﬁ es the major NFF cost drivers across the supply chain (e.g. transportation), the OEM (e.g. inventory) and the customer (e.g. lost man hours). An agent based model is used to evaluate the impact of these cost drivers on the overall NFF cost. The analysis shows how the most appropriate drivers can be selected to represent the cumulative costs due to NFF events and their impacts across the supply net- work. From the academic perspective, the generic framework for NFF cost estimation demonstrates how qualitative and quantitative information can be used together to achieve maintenance objectives. From a practical perspective, by applying the framework on one component, an organisation has the liberty to analyse the cost of NFF for that particular unit only.
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with xenograft. Of the grade 4 patients, 121 underwent repair reinforced with xenograft and 85 underwent primary repair. Four patients in the grade 4 group were assumed to have had synthetic mesh used during hernia repair because mesh not subsequently implanted was removed more than 90 days fol- lowing the index repair. These patients were excluded from comparative analyses due to small sample size. No differences were found in population characteristics, including age, gen- der, and percentage of patients who were morbidly obese or had diabetes. Among grade 3 patients, significantly fewer of those with xenograft had pre-existing complications (60.7%) compared with synthetic mesh patients (75%) and primary repair patients (79.9%, P , 0.05). Table 3 shows the popula- tion characteristics of patients with grade 3 and 4 hernias. There was no statistically significant difference in average length of stay for index episodes by type of repair for grade 3 and 4 patients (Table 4). Grade 4 patients stayed in hospital 4.8 days longer, on average. Laparoscopic repair was used in 8% of index events (10% in grade 3 patients; 1% in grade 4 patients). CPT 15734 (muscle-skin graft, trunk) was identified in 5% of index events (4% in grade 3; 8% in grade 4).
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