Average Operating Cost Research Articles

Manajemen Sumber Dana dan Alokasi Pembiayaan Pada Pesantren Mahasiswa

This study aims to find out how the management of financing management in Islamic boarding school students Ma’had Lughowy. The focus of this investigation is to reveal where Ma'had Lughowy's funding sources are, how Ma'had Lughowy's funding allocations are and how student-based boarding schools carry out their activities. The method used in this research is the cost-benefit analysis (CBA) method presented by descriptive analysis with a qualitative approach. The results of the investigation show that there is still a management of financing that is not in accordance with the concept of management in general in Ma'had Lughowy. (2) in its implementation, ma'had needs an average operational cost budget of Rp. 10,000,000.00 to Rp. 15,000,000.00 every month and to meet the needs of students who are quite a lot of managers using a strategy of 100% of the income of 20% saved for savings funds and another 80% is managed for a budget for one year. (3) Ma'had Lughawy still has an existence up to now due to several factors, among others, because ma'had has become a necessity for students, as a means that is intentionally formed to equalize students' academic abilities, to be a solution for housing choices with a good environment for students and as one of the graduation requirements. Therefore it is necessary to have a good strategy in managing the sources and allocation of funds in accordance with the management concepts that exist in student boarding schools.

Determinants of net interest margin: the effect of capital requirements and deposit insurance scheme

ABSTRACTThis paper analyzes the determinants of net interest margin with a focus on the impact of capital regulation and deposit insurance. We extend the Ho and Saunders (1981) family of models to explicitly include both capital requirement and the deposit insurance premium as determinants of net interest margin. The model predicts that the higher the capital requirements and deposit insurance premium, the higher banks’ interest rates will be. We test the theoretical model using panel data for OECD countries between 2000 and 2014. Our results support the positive relationship between both the capital requirement and the deposit insurance premium on interest margins. The most important determinants of the net interest margin are implicit payments, efficiency, average operating costs, the intensity of competition, the deposit insurance premium and capital stringency.

Optimal Sizing and Energy Management for Cost-Effective PEV Hybrid Energy Storage Systems

In battery/ultracapacitor (UC) hybrid energy storage systems (HESS), sizing and energy management strategies are crucial, which determine the system cost and performance. However, research on these two problems in a coupled manner for plug-in electric vehicles is still immature. This article aims at resolving this issue in the perspective of minimizing the average operating cost. Both manufacturing cost and system end-of-life timing are incorporated. A quantitative battery degradation model is employed to evaluate the battery dynamic capacity loss and cycle life. Dynamic programming algorithm is then deployed to achieve optimal power distribution between battery and UC. Furthermore, the power management and HESS optimal sizing strategies are unified into a single cost-minimization problem. Combining those efforts, the optimal size of the HESS with minimized average operating cost is solved by simulated annealing method. Optimization results illustrate that a minimum cost of 15.52 USD is achieved with 72 UC cells and 7100 battery cells. A large set of simulation data has proved the optimality of the optimization results. Compared with the battery-only solution, the proposed solution demonstrates 11.9% cost reduction and 21.7% battery cycle life extension under the Urban Dynamometer Driving Schedule. Moreover, the temperature rise of the battery is reduced by 31.1%. Finally, based on the optimal results, the energy management strategy is extended to fit real-time applications by utilizing Markov chain and stochastic dynamic programming.

Managing component degradation in series systems for balancing degradation through reallocation and maintenance

In a physical system, components are usually installed in fixed positions that are known as operating slots. Due to such reasons as user behavior and imbalanced workload, a component’s degradation can be affected by the corresponding installation position in the system. As a result, components degradation levels can be significantly different even when the components come from a homogeneous population. Dynamic reallocation of the components among the installation positions is a feasible way to balance the extent of the degradation, and hence, extend the time from system installation to its replacement. In this study, we quantify the benefit of incorporating reallocation into the condition-based maintenance framework for series systems. The degradation of components in the system is modeled as a multivariate Wiener process, where the correlation between the degradation is considered. Under the periodic inspection framework, the optimal control limits for reallocation and preventive replacement are investigated. We first propose a reallocation policy of two-component systems, where the degradation process with reallocation and replacement is formulated as a semi-regenerative process. Then the long-run average operational cost is computed based on the stationary distribution of its embedded Markov chain. We then generalize the model to general series systems and use Monte Carlo simulations to approximate the maintenance cost. The optimal thresholds for reallocation and replacement are obtained from a stochastic response surface method using a stochastic kriging model. We further generalize the model to the scenario of an unknown degradation rate associated with each slot. The proposed model is applied to the tire system of a car and the battery system of hybrid-electric vehicles, where we show that the reallocation policy is capable of significantly reducing the system’s long-run average operational cost.

A fault-tolerant aware scheduling method for fog-cloud environments.

Fog computing is a promising technology that leverages the resources to provide services for requests of IoT (Internet of Things) devices at the cloud edge. The high dynamic and heterogeneous nature of devices at the cloud edge causes failures to be a popular event and therefore fault tolerance became indispensable. Most early scheduling and fault-tolerant methods did not highly consider time-sensitive requests. This increases the possibility of latencies for serving these requests which causes unfavorable impacts. This paper proposes a fault-tolerant scheduling method (FTSM) for allocating services’ requests to the most sufficient devices in fog-cloud IoT-based environments. The main purpose of the proposed method is to reduce the latency and overheads of services and to increase the reliability and capacity of the cloud. The method depends on categorizing devices that can issue requests into three classes according to the type of service required. These classes are time-sensitive, time-tolerant and core. Each time-sensitive request is directly mapped to one or more edge devices using a pre-prepared executive list of devices. Each time-tolerant request may be assigned to one or more devices at the cloud edge or the cloud core. Core requests are assigned to resources at the cloud core. In order to achieve fault tolerance, the proposed method selects the most suitable fault-tolerant technique from replication, checkpointing and resubmission techniques for each request while most existing methods consider only one technique. The effectiveness of the proposed method is assessed using average service time, throughput, operation costs, success rate and capacity percentage as performance indicators.

Estimating and predicting the operational costs of road tolls: An econometric assessment using panel data

We develop an econometric procedure to estimate the operational costs of toll road projects. To show its usefulness for planning future tolls, we test its predictive power on out-of-the sample observations. Thus, the rationale for the paper is that previous studies have utilized less succinct econometric frameworks to derive factors that significantly explain the operational costs of toll roads and have provided little evidence regarding the predictive power of the models used. Panel data on 33 Norwegian toll road projects observed during the period 2011–2015 are used for the purpose, resulting in a total of 165 observations. The results reveal the following: (i) Toll operations are heterogeneous, so that individual characteristics matter; ceteris paribus, this should be accounted for when estimating operational costs. (ii) The average operational cost per vehicle (AVC) processed at tolls is approximately 4 NOK (≈ US$ 0.44). (iii) The volume of vehicle throughput reduces operational costs, demonstrating the existence of scale economies; the number of lanes served increases operational costs; the use of an Open Road Toll (ORT) charging system reduces operational costs; the tendering of toll collections reduces operational costs; and the share of vehicles that use On Board Units (OBU) reduces operational costs. It is shown that the econometric model developed here has high predictive power and can be used to predict the operational costs of future tolls. These results reaffirm the results of some earlier studies but serve to warn that one should not be indifferent to the framework of analysis used, as the results may not be statistically significant and robust. The econometric framework developed here is an advance due to its predictive power.

Experimental short-term investigation of model predictive heat pump control in residential buildings

This study investigates the potential of model predictive heat pump control in detached houses in terms of electric energy consumption, thermal comfort and photovoltaic energy self-consumption. Two comparable test rigs with identical devices are set up. The test rigs include electrical air source heat pumps with variable compressor speed, thermal energy storages and heat dissipation by heat exchangers. The heat demand is controlled by valves, which are coupled to real-time simulation of building models in compliance with the principle of energy conservation. Measurements confirm test rig comparability. After introducing the model predictive control (MPC) concept, a successive series of six measurements of 120 h each within the heating season is presented. The model predictive heat pump controller is evaluated by comparison to a standard heat pump controller implemented into the reference test rig. Results show an average increase of the heat pump coefficient of performance of 22.2%, an average increase of 234.8% in terms of photovoltaic energy self-consumption as well as a resulting average heat pump operational cost reduction of 34.0% by application of MPC.

A stochastic programming model for the optimal operation of unbalanced three-phase islanded microgrids

This paper presents a stochastic mixed-integer nonlinear programming (MINLP) model for the optimal operation of islanded microgrids in the presence of stochastic demands and renewable resources. In the proposed formulation, the microgrid is modeled as an unbalanced three-phase electrical distribution system comprising distributed generation (DG) units with droop control, battery systems (BSs) and wind turbines (WTs). The stochastic nature of the consumption and the renewable generation is considered through a scenario-based approach, which determines the optimal values of the decision variables that minimize the average operational cost of the microgrid. A set of efficient linearizations are used to transform the proposed MINLP model into an approximated convex model that can be solved via commercial solvers. In order to assess the effectiveness of the obtained solution, Monte Carlo simulations (MCS) are carried out. Results show that the proposed model considers the uncertainty while reducing the average operational costs and load curtailments, when compared with a deterministic model.

Analisis Determinasi Tingkat Net Core Operational Margin Pada Bank Umum Syariah di Indonesia

Purpose- The purpose of this study is to explore the impact of a bank’s internal and external factors on net core operating margin in Indonesia’s Islamic commercial bank's companies.
 Methods- A quantitative approach by using panel data regression with a period from 2nd quarter 2010 to 2nd quarter 2015. The object of this study is eight Islamic commercial banks companies which were listed in sharia bank directory of Central Bank of Indonesia and Financial Services Authority of the Republic of Indonesia, those selected by purposive sampling technique with specific criteria.
 Findings- This study can be concluded that capital adequacy ratio and average operational cost have a positive and significant impact on the net core operational margin. On the contrary, financing to deposit ratio, bank size, operational efficiency ratio, and BI rate have a negative and significant impact on net core operational margin.
 Research implications- The management needs to create an efficient banking system by reducing operational costs and improving management quality. Banks are also advised to increase the prudential principle in managing finance so that the risk of default can be minimized.

Optimization of the Number and Frequency of Repairs

When managing the production process at an enterprise, it is important to correctly develop a policy for overhauls of machinery and equipment. Usually for this purpose, enterprises use the standards for the repairs frequency recommended in the literature. In publications on the reliability theory, repair policy is considered as an optimization problem. In publications on the theory of reliability, this problem is considered as optimization. In this case, usually the criterion of optimization is some kind of relative indicator, such as availability rate or average operating costs per unit of time. However, such criteria do not fully reflect the economic interests of enterprises – owners of equipment. In a market economy, these enterprises are focused on maximizing their market value. In this paper, we propose to form a repair policy in which the market value of the enterprise, and therefore all its assets, will be most. The corresponding mathematical model is the best use underling the valuation theory. It also takes into account the physical deterioration of machines during their operation, as well as the possibility of random marginal failures, leading to the need to stop using the machine. In this case, the improvement of the technical condition of the machine after its overhaul is described using the Kijima imperfect repair model. The calculations carried with our model allow establishing how the optimal number and timing of repairs depend on such parameters as repair cost and its restoration factor, the rate of physical wear of machines, and the intensity of their resource failures. We show how to use the constructed model to take into account the effect of inflation rates and income and property tax rates on the repair policy.

Cost Economies for an Airline: An Analysis of Airlines’ Operating Costs

This study focuses on analyzing the variables affecting the average operating cost per aircraft movement. Since airlines around the world are operated on thin profit margins and with increasing competition from Low Cost Carriers it will be important for an airline to get a complete understanding about their operating cost structure. The aim of this study is to suggest an airline of actions to reduce their operating cost and will differentiate the cost structures of Low Cost Carriers and Full Service Carriers. This study was conducted for 20 airlines which were operating in Asia Pacific region. Published financial and statistical data were used for analysis and a parametric approach was used. The results of this study do not suggest economies of scale for the airline, which is to have higher number of aircraft to reduce cost.

Cost Economies for an Airline: An Analysis of Airlines’ Operating Costs

This study focuses on analyzing the variables affecting the average operating cost per aircraft movement. Since airlines around the world are operated on thin profit margins and with increasing competition from Low Cost Carriers it will be important for an airline to get a complete understanding about their operating cost structure. The aim of this study is to suggest an airline of actions to reduce their operating cost and will differentiate the cost structures of Low Cost Carriers and Full Service Carriers. This study was conducted for 20 airlines which were operating in Asia Pacific region. Published financial and statistical data were used for analysis and a parametric approach was used. The results of this study do not suggest economies of scale for the airline, which is to have higher number of aircraft to reduce cost.

Development of a model for economic control of loading in sublevel caving mines

ABSTRACTThis paper presents an economic model for optimizing loading at the draw point in sublevel caving (SLC) operations. The input data consist of estimated bucket grades based on bucket weights from Load Haul Dump machines. This information, together with average operational mining costs, was used to create an economic model providing a real-time economic assessment of the draw point performance for SLC rings. The results demonstrate the importance of continuous draw point monitoring to optimize SLC operations. The proposed model provides an economic assessment of operating draw points and will help mine personnel to decide when to stop loading from a blasted ring. It can also help mine management understand the complexity of material flow in SLC operations. Finally, it provides operational flexibility for the mine to optimize loading at the draw point by increasing ore recovery while maintaining operational control of draw point performance.

An agent-based approach to evaluate collaborative strategies in milk-run OEM operations

The management of transport operations is a promising field for agent-based applications. Acting in a collaborative way, the agents can be seen as a multi-agent system that enables vehicles to handle new information perceived during the operation along cargo collecting routes. Traditional research in this field usually focus on the servicing of new transportation demands, in this paper the agents could detect the presence of unexpected traffic congestions and deciding about the transference of tasks to others vehicles. This article evaluates collaborative strategies for applying the agent-based approach to a dynamic vehicle routing formulation, where vehicles are assigned to picking-up components and parts from Original Equipment Manufacturer suppliers. A sequential probabilistic ratio test is used to predict eventual unperformed collecting tasks. Two evaluating criteria are simultaneously used to select a specific collaborative strategy: the service level, represented by the average percentage of performed tasks, plus the average daily operating cost of the vehicle fleet. The evaluation of collaboration strategies between vehicles allowed understand the functioning of distributed decision making, contributing to the adoption of autonomous control methods of transportation operations.

Reliability-oriented design of integrated model of preventive maintenance and quality control policy with time-between-events control chart

Superior manufacturing quality is prerequisite to continuously produce reliable products, and the proactive product reliability assurance is always a crucial routine task for manufacturing. Therefore, this paper presents a reliability-oriented optimization model for joint preventive maintenance (PM) and process quality control with time-between-events (TBE) control chart, where the impact of manufacturing process on product final reliability is considered to reduce the product reliability degradation originating from latent manufacturing defects. Firstly, as the foundation of reliability-oriented control, the product reliability degradation mechanism in manufacturing stage is analyzed, and the process variations of product critical-to-reliability characteristics and internal defects are considered to model the product actual reliability. On this basis, periodical PM and TBE chart are jointly applied to enhance machine performance and improve manufacturing process quality to reduce potential reliability degradation, and a three-scenario model is proposed. Then, to evaluate the performance of the integrated model, the occurrence probability, expected reliability degradation, average operational cost, and cycle time of each scenario are analyzed, and the joint policy is optimized to minimize the expected reliability degradation of batch products within a limited cost range. Finally, a case study is presented to verify the performance of the developed model by comparing it with a pure planned maintenance policy, and a sensitivity analysis is conducted to analyze the impacts of model parameters.

Analysis of clinical effect on 19 cases of inguinal hernia treated by laparoscopic totally extraperitoneal repair

Objective To investigate the effect of laparoscopic total extraperitoneal tension-free hernia repair (TEP) in the treatment of inguinal hernia with absorbable biological mesh. Methods A retrospective analysis of the clinical data of 19 patients with inguinal hernia with biological mesh was performed from September 2015 to September 2016 in Shengjing Hospital of China Medical University. The average operative time, average incision pain time, average postoperative venting time, average hospital stay, average operative cost, and long-term chronic pain, postoperative complications, and recurrence rate were observed. Results All the 19 patients were successfully operated. The average operation time was (35.0±4.0) min, the average incision pain time was (1.5±0.6) d, and the average postoperative venting time was (1.5±1.2) d. The average hospital stay was (4.5±0.9) d, the average surgery cost was (23 534.6±1 259.9) yuan. Two patients developed swelling of the scrotum after surgery, and one patient developed postoperative fat liquefaction. All patients were followed up for 1 year by telephone, with no recurrence, no serious complications, and chronic pain discomfort. Conclusions The application of absorbable biopsy TEP is a good and reliable way to treat inguinal hernia. Postoperative patients have mild pain and low complication rate. There is no recurrence in recent follow-up, and the short-term effect is satisfactory. It is a reliable method for the treatment of inguinal hernia. The cost is high, and can be selected according to age and individual needs. Key words: Hernia, inguinal; Laparoscopes; Laparoscopic totally extraperitoneal repair; Biological mesh; Tension-free repair

A Bank Size and Competitive Advantage in the UK Banking Sector

To investigate the association between return to scale (RTS) and profitability in the United Kingdom banking sector, we adopted logistic regression analysis, using sample sizes of 135, 140, and 121 banks for the years 2016, 2015, and 2014, respectively. Our findings indicate a positive and statistically significant association between profits as measured by return on assets (ROA) and increasing RTS during the three years of the sample period. We also investigated the relationship between bank size as represented by the log of total deposits and RTS. Our findings also indicate that bigger banks show increasing RTS, but with decreasing rate, as represented by the negative coefficient of the square of the log of deposits. To investigate further the link between bank size and operating cost with ROA, we employed panel data regression, covering the sample period (2011-2016) for the largest 25 banks. Our results show that there is a positive and significant association between ROA and the total assets of the largest banks, but the operating expenses impact negatively on the ROA. More specifically, 1% increase in total assets increase ROA by 2, and 1% increase in the operating expenses reduce ROA by 1.7%. These results imply that bigger banks in the United Kingdom’s banking sector are able to gain competitive edge in attracting deposits as they operate along the downward sloping portion of average operating cost curve.

Multistage treatment technology for leachate from mature urban landfill: Full scale operation performance and challenges

In the present work, a multistage treatment strategy was applied to a mature urban leachate, at full scale. The treatment system consisted of (i) a sequential batch reactor (SBR), for nitrification/denitrification processes, followed by (ii) a coagulation/sedimentation (C/S) stage, (iii) an advanced oxidation process, in this case the photo-Fenton (PF) reaction, and (iv) a final SBR. Glycerol, a waste-product from biodiesel production, was successfully employed as an external carbon source for denitrification purposes. The C/S and PF stages were conducted in the same tank, which was coupled to 4 FluHelik photoreactors connected in series, thus enabling a compact solution for the multistage facility. The major operational difficulties were found in the: (i) C/S stage, due to the production of dense foam that trapped the sludge; and (ii) PF stage, for iron precipitation. These problems were overcome, respectively, with: (i) sludge removal after nitrite oxidation with hydrogen peroxide (intermediate step prior to PF); and (ii) maintenance of a residual amount of H2O2 before neutralization step. Each treatment sequence was applied to ca. 30 m3 of urban leachate after an aerated lagoon, leading to global removal efficiencies of 98% for COD (from 8.30 to 0.15 g O2/L), 97% for DOC (from 2.32 to 0.08 g C/L) and 85% for TN (from 2.65 to 0.41 g N/L). The sludge produced was also treated in-situ and the compliance with legal disposal standards was verified. The average total operational cost for the complete treatment sequence was 6.7 €/m3, including reagents, energy consumption, sludge treatment and respective disposal.

Effect of Ordering Policies on Complex Dynamics Behaviours in a Discrete-Type Manufacturing Industry Supply Chain System

The beer game model is a typical paradigm used to study complex dynamics behaviours in production–distribution systems. The model, however, does not accord with current practical supply chain system models in discrete-type manufacturing industry, which are generally composed of retailers, distributors, manufacturers with internal supply chain, and suppliers. To describe how ordering policies influence the complex dynamics behaviour modes and operating cost in a general discrete-type manufacturing industry supply chain system, a high dimension piecewise-linear dynamics model is built for the supply chain system. Five kinds of ordering policy combination are considered. The distribution of both the largest Lyapunov exponent of effective inventory and average operating cost per cycle is obtained by simulation in a policy space. The simulation shows that for the general discrete-type manufacturing industry supply chain system, the upper chaotic corners emerge besides the lower chaotic corners in the policy space expressing the distribution of system behaviour mode, and that the ordering policies at each supply chain node as well as their combination have very significant effect on the topology of the distribution of both system behaviour mode and operating cost in the policy space. We find that chaos is not always corresponding to high cost, and the “chaos amplification” is not completely relevant to the “cost amplification”.

The Role of Education Operating Costs Against the Output on Madrasah Aliyah in Indonesia

The purpose of this study was to determine the role of fishers’ operational costs on the output of education in Madrasah Aliyah in Cimahi. This research uses descriptive study method because the problems studied are actual and factual so that researchers are able to study intensively about the background of the present situation. In this study, the authors used several data collection techniques, namely observation, interviews and documentation studies. In this study, there were 2 Aliyah Madrasas which became the object of the sample to be used as a comparison so that the researchers knew the role of educational operational costs on educational output namely Madrasah Aliyah Mutiteknik Asih Putera and Madrasah Aliyah Al-Farisy. Whereas the output of education in this study is seen from the value of the average NEM of Student Exams from each school. From various data obtained by the author about elite objects, the results of the study indicate that the role of educational operational costs in this study has an influence on educational output. This means that the high average operational costs of education result in better outputs of education.