scholarly journals Replacement Model for Street Lighting Systems

2021 ◽  
Vol 40 (1) ◽  
pp. 49-55
Author(s):  
A.M. Usman ◽  
Y.A. Adediran ◽  
A.O. Otuoze ◽  
O.O. Mohammed ◽  
O.S. Zakariyya
Keyword(s):  
Field Survey ◽  
Optimal Time ◽  
North Central ◽  
Street Lighting ◽  
Maintenance Costs ◽  
Optimal Replacement ◽  
Replacement Model ◽  
Lighting Systems ◽  
The University ◽  
Replacement Time

Replacing failed bulbs of streetlights in a location can be very tasking and expensive if the optimal time for replacement is not determined. In this paper, a model has been developed that helps to establish the optimal time for the replacement of streetlight bulbs. Burnt-out bulbs are replaced individually when they fail, and group replacement is carried out on all bulbs after a specified time. The costs for both individual replacement and group replacement are determined. The developed model was applied to locally sourced data from a field survey of a streetlight installation at the University of Ilorin, Ilorin, North-central Nigeria. The model gave the optimum replacement time of burnt-out bulbs as the eighteenth week when applied to the data used in this work. The optimum replacement time will be dependent on the dataset used. This makes the developed model useful in establishing the optimal replacement time of any stochastically failing items that are in large quantities. The model will help to reduce maintenance costs for facility managers.

Forecasted Inflation Based Block Replacement Model Using Stochastic Process

2014 ◽  
Vol 592-594 ◽  
pp. 2716-2722
Author(s):  
B. Srinivas ◽  
S. Gajanana ◽  
K. Hemachandra Reddy
Keyword(s):  
Interest Rates ◽  
Present Model ◽  
Entire Group ◽  
Cyclical Fluctuation ◽  
Optimal Replacement ◽  
Replacement Model ◽  
The Individual ◽  
The Cost ◽  
Replacement Time ◽  
The Ideal

The replacement problems are concerned with the situation that arises on decrease in the efficiency of the item, failure or breakdown. The problem of replacement is to identify the best policy to determine the ideal replacement time which is most economical. Group replacement model is applicable to the items that fail completely on usage and the result is group replacement age for the entire group of items in the system irrespective of whether they are functioning or not. The present paper proposes intermediate states i.e., minor repair and major repair states in between functioning and irreparable breakdown states. In addition, higher order Markov chains are used in generating the probabilities of items which are falling in different states. In order to consider money value, macro-economic variable, inflation is considered in this model. In the present model, real interest rates are calculated using forecasted inflation for future periods. Future period values of inflation are predicted by using the forecasting technique and a regression model with trigonometric function. These methods are used to accommodate cyclical fluctuation in the prices of items/inflation. The optimal replacement age is the time bucket in which the average cost of the individual replacement, repair and the cost of the items is minimum.

scholarly journals Delayed Age Replacement Policy with Uncertain Lifetime

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Xueyan Li ◽  
Chunxiao Zhang
Keyword(s):  
Time Span ◽  
Replacement Policy ◽  
Infinite Time ◽  
Uncertainty Distribution ◽  
Uncertain Variables ◽  
Optimal Replacement ◽  
Replacement Model ◽  
Age Replacement ◽  
Uncertain Distribution ◽  
Replacement Time

This paper considers the delayed age replacement policy, in which the lifetimes of all units are assumed to be uncertain variables, and the lifetime of the first unit has an uncertainty distribution which is different from the others. A delayed age replacement model which is concerned with finding the optimal replacement time to minimize the expected cost is developed. In the policy, the optimal replacement time is irrelevant to the uncertain distribution of lifetime of the first unit over the infinite time span.

Design of Solar-Powered LED Road Lighting System

2019 ◽  
pp. 75-85
Author(s):  
Canan Perdahci ◽  
Hamdi Ozkan
Keyword(s):  
High Pressure ◽  
Renewable Energy Sources ◽  
Junction Temperature ◽  
Mercury Vapour ◽  
Light Sources ◽  
Street Lighting ◽  
Led Light ◽  
Road Lighting ◽  
Lighting Systems ◽  
High Pressure Sodium Lamp

Turkey is rich in terms of renewable energy sources and, therefore, is now encouraging the use of sustainable clean lighting systems in road applications. High pressure sodium lamp is the most widely used type in main roads, but other types of lamps such as mercury vapour lamps or metal halide lamps can be utilized for street lighting. Since it enables energy and money saving, LED light technology has replaced high pressure sodium lamps nowadays. Once solar power system (PV) is integrated with LED lamp for street lighting, the amount of saving and local impact might be enriched. LEDs used as light sources in road lighting luminaires with rising lumen values, decreasing junction temperature, higher colour rendering efficiency, longer lifetime have become more efficient than many light sources with the latest developments. Since the structure of the luminaires in which the LED light sources are used differs from that of the conventional light sources, the optical, thermal and electrical design of the LED luminaires must be considered differently. Thus, this study concentrates upon design considerations and the operating principle of solarpowered LED road lighting luminaire in details. Also, a simple solar panel system was designed and the economical values obtained at the end of 20 years were compared when using the ongrid system and the off-grid system.

Multi-objetive Optimization applied to Photovoltaic Street Lighting Systems

2014 ◽  
pp. 594-598 ◽  
Author(s):  
O. Rabaza ◽  
Z.E. Palomares-Muñoz ◽  
A.M. Peña-García ◽  
D. Gómez-Lorente ◽  
J. Arán-Carrión ◽  
...  
Keyword(s):  
Street Lighting ◽  
Lighting Systems

scholarly journals A study on the reliability and performance of solar powered street lighting systems

2017 ◽  
Vol 5 (2) ◽  
pp. 110 ◽  
Author(s):  
Adebayo Fashina ◽  
Salifu Azeko ◽  
Joseph Asare ◽  
Chukwuemeka Ani ◽  
Vitalis Anye ◽  
...  
Keyword(s):  
Performance Indicators ◽  
Performance Ratio ◽  
Energy Yield ◽  
Street Lighting ◽  
Technical Performance ◽  
Humid Environment ◽  
Total Failure ◽  
Lighting Systems ◽  
And Performance ◽  
Solar Powered

This paper presents the results of a study on the reliability and performance of the solar-powered street lighting systems installed at the African University of Science and Technology (AUST) in Nigeria, a hot and humid environment. The technical performance of the systems was studied using the following performance indicators: system energy yield, capture loss, as well as the system performance ratio while the reliability of the systems was examined using a model developed from the findings from the maintenance and fault diagnosis of the systems. The model was used to predict the total failure and survival probability of the systems using the Weibull distribution. The performance evaluation during the monitored period (February 2012 to January 2015) indicated that the performance ratios of the systems vary from 70% to 89% and the energy yields of the systems ranging from 2.87 h/day to 5.57 h/day. The results from the reliability analysis also showed that when the stress concentration factor around the notch between the cable terminals in the charge controller increases, the charge controller will become overheated, which in turn affected other components of the systems. The implications of this study are also discussed for the design and development of future solar-powered street lighting systems.

scholarly journals Impact of Quota System and Catchment Area Policy on the University Admissions in North Central Nigeria

SAGE Open ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 215824401665495
Author(s):  
Joachim Chinweike Omeje ◽  
Ene Inyamu Egwa ◽  
Victoria Ogwa Adikwu
Keyword(s):  
Catchment Area ◽  
Quota System ◽  
University Admissions ◽  
North Central ◽  
The University

scholarly journals Repair and maintenance costs of 4WD tractors and self propelled combine harvesters in Italy

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Aldo Calcante ◽  
Luca Fontanini ◽  
Fabrizio Mazzetto
Keyword(s):  
Cost Estimation ◽  
Working Hours ◽  
The United States ◽  
Operating Conditions ◽  
List Price ◽  
Optimal Time ◽  
Model Parameters ◽  
Maintenance Costs ◽  
Combine Harvesters ◽  
Engine Power

Purchasing and maintaining tractors and operating machines are two of the most considerable costs of the agricultural sector, which includes farm equipment manufacturers, farm contractors and farms. In this context, repair and maintenance costs (R&M costs) generally constitute 10-15% of the total costs related to agricultural equipment and tend to increase with the age of the equipment; hence, an important consideration in farm management is the optimal time for equipment replacement. Classical, R&M cost estimation models, calculated as a function of accumulated working hours, are usually developed by ASAE/ASABE for the United States operating conditions. However, R&M costs are strongly influenced by farming practices, operative conditions, crop and soil type, climatic conditions, etc. which can be specific for individual countries. In this study, R&M cost model parameters were recalculated for the current Italian situation. For this purpose, data related to the R&M costs of 100 4WD tractors with engine power ranging from 59 to 198 kW, and of 20 SP combine harvesters (10 straw walkers combines and 10 axial flow combines) with engine power ranging from 159 to 368 kW working in Italy were collected. According to the model, which was obtained by interpolating the data through a two-parameter power function (proposed by ASAE/ASABE), the R&M cost incidence on the list price of Italian tractors at 12,000 working hours (estimated life of the machines) was 48.6%, as compared with 43.2% calculated through the most recent U.S. model while, for self propelled combine harvesters, the R&M cost incidence at 3,000 working hours was 23.1 % as compared with 40.2% calculated through the same U.S. model.

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