scholarly journals Analyzing the Finishing Works Service Life Pattern of Public Housing in South Korea by Probabilistic Approach

2018 ◽  
Vol 10 (12) ◽  
pp. 4469 ◽  
Author(s):  
Soyeon Park ◽  
Yonghan Ahn ◽  
Sanghyo Lee
Keyword(s):  
Service Life ◽  
Public Housing ◽  
Probabilistic Approach ◽  
Housing Developments ◽  
Life Patterns ◽  
South Korean ◽  
Service Lifetime ◽  
Life Pattern ◽  
Term Maintenance

Over recent decades, it has become essential to establish preventive long-term maintenance plans for public housing developments. Also, deterministic maintenance strategies have been increasingly replaced by those based on reliability and risk, which are probabilistic. Efforts to obtain optimized long-term maintenance plans have included management of service life and prediction of service lifetime. Accordingly, the present research develops a system for various finishing works of public housing and analyzes the service life pattern of each component using a probabilistic approach. For the analysis, this research analyzed 46,201 South Korean public housing maintenance records from the last 21 years and determined the maintenance frequency distribution. The purpose of the research is to suggest efficient long-term maintenance plans using the analyzed results of service life patterns. Results from the analysis showed that each component has a different service life pattern that can be applied to establish the service lifetime and decision making for floating maintenance. Since the interaction between finishing works is affected due to various components and parameters, the results are useful to reduce the uncertainty and risk of deterministic maintenance plans. The meaning of this research is to analyze the service life pattern using a probabilistic approach and recommend how to establish an efficient maintenance system.

scholarly journals Analyzing the Long-Term Service Life of MEP Using the Probabilistic Approach in Residential Buildings

2018 ◽  
Vol 10 (10) ◽  
pp. 3803 ◽  
Author(s):  
Sanghyo Lee ◽  
Yonghan Ahn
Keyword(s):  
Decision Making ◽  
Service Life ◽  
Residential Buildings ◽  
Probabilistic Approach ◽  
Life Time ◽  
Probabilistic Methods ◽  
The Cost ◽  
Maintenance Plan ◽  
Term Maintenance

Establishing an effective long-term maintenance plan is essential to ensure the sustainability of a building. Among the various components of a building, the mechanical, electrical, and plumbing (MEP) components are complexly affected by various parameters, such as quality and user pattern, with respect to the service life. Besides, these components are replaced at different points in time, which becomes one of the main risks when establishing a maintenance plan for the building. Therefore, it is very important to consider the uncertainty in calculating the service lives of MEP components in a systematic and reasonable way. This study aims to systemize the MEP components of residential buildings and analyze their service life patterns using a probabilistic approach for long-term maintenance planning. The analysis was performed on 54,318 maintenance cases from 1998 to 2017 at 65 twenty-five-year-old rental apartment buildings in South Korea. Before performing the analysis, a service life matrix was established by classifying the MEP components into 12 types and setting the service life time at 6–25 years. Then, the service life distribution was derived for each MEP component. The probabilistic approach can provide information for rational maintenance decision-making regarding each MEP component as well as basic service life settings. Since the performance of the MEP components deteriorates due to various reasons, de facto uncertainty exists in the service life of each component; thus, the probabilistic approach can serve as an important decision-making method. If probabilistic methods are developed by acquiring the cost data in addition to the frequency of maintenance activity used in this study, a more effective long-term maintenance plan can be established.

Software-Defined Radio for Positive Train Control

2012 ◽  
Author(s):  
Jon T. Adams ◽  
Jia-Ru Li
Keyword(s):  
Service Life ◽  
Software Defined Radio ◽  
Network Access ◽  
Total Cost Of Ownership ◽  
Total Cost ◽  
Train Control ◽  
Cost Of Ownership ◽  
Positive Train Control ◽  
Term Maintenance

United States (US) Freight and Passenger railroads and transit entities are preparing for the deployment of Positive Train Control (PTC) systems as soon as the end of 2012, and by Federal mandate, by the end of 2015. PTC depends on a reliable and robust wireless data link between train and wayside equipment, train and network access points, and waysides and network access points. While, for the wireless component, some spectrum has been acquired and initial functionality defined, there will be lessons learned and new expectations as systems are rolled out over this period and beyond. Since the average service life of radio equipment in rail and transit applications is in excess of 10–15 years, and a system design may remain in place for 20–25 years, the challenge is to ensure that wireless systems are flexible enough to adapt to technology changes that may occur during the radio system’s long service life. Software-Defined Radio (SDR) is the appropriate approach to deal with this future uncertainty. The worldwide cellular communications standards are a great example: 3GPP established its first 3G specification, Release-99, in the year 2000; there have been 7 full specification releases since then, demonstrating the challenges of predicting future use based on current expectation. Deployment and long-term maintenance account for the majority of system cost: when system deployment is expensive and time-consuming, the needs for flexible design are crucial. The maintenance cost should be added and weighted higher in the calculation for total cost of ownership. One can argue that fixed design is cheaper; however, the total cost of ownership may end up much higher when changes are needed before the end of the product’s expected service life. In Information Technology, the system performance doubles approximately every 18–24 months. Thoughtful radio design can leverage this generational improvement. To address the issue of broad interoperability and a forward-looking specification, radio experts, including transit systems integrators, Federal agencies, end device and chipset manufacturers, and researchers, from around the world have teamed up under the aegis of the Institute of Electrical and Electronic Engineers (IEEE) to establish a Positive Train Control group for the RF/PHY/MAC based upon the well adopted IEEE 802.15.4 standard. The outcome of this effort will ensure the maturity of a PTC specification and long term maintenance of this mission-critical PTC wireless interface protocol. With any new specification development, continuous vetting, modification and upgrade will occur over coming years to improve the functionality and stability. SDR architectures allow the radio system to follow the standard. SDR allows railroads to start system validation and hardware qualification now, in order to meet the required Federal deadline. Since SDR provides a continuous path for interoperability as radios can reprogram and reconfigure on the fly, the hardware can remain unchanged while interoperability and advances in standards can be met through software upgrade.

Efficacious long-term maintenance therapy with pantoprazole (PAN) in patients with Zollinger-Ellison syndrome

2001 ◽  
Vol 120 (5) ◽  
pp. A613-A613
Author(s):  
P BORNMAN ◽  
K RADEBOLD ◽  
H DEBAERE ◽  
L VENTER ◽  
H HEINZE ◽  
...  
Keyword(s):  
Maintenance Therapy ◽  
Zollinger Ellison Syndrome ◽  
Term Maintenance

CARBONATION INDUCED CORROSION ANALYSIS OF REINFORCED CONCRETE STRUCTURES BASED ON FULL PROBABILISTIC APPROACH – AN INDONESIAN CASE STUDY

2018 ◽  
Vol 4 (1) ◽  
pp. 165
Author(s):  
Herry Prabowo ◽  
Mochamad Hilmy
Keyword(s):  
Service Life ◽  
Probabilistic Approach ◽  
Concrete Structures ◽  
Weather Condition ◽  
Analysis Data ◽  
National Standard ◽  
Concrete Carbonation ◽  
Durability Design ◽  
Starting Point ◽  
Real Performance

The assessment of the service life of concrete structures using the durability design approach is widely accepted nowadays. It is really encouraged that a simulation model can resemble the real performance of concrete during the service life. This paper investigates the concrete carbonation through probabilistic analysis. Data regarding Indonesian construction practice were taken from Indonesian National Standard (SNI). Meanwhile, data related to Indonesian weather condition for instance humidity and temperature are taken from local Meteorological, Climatological, and Geophysical Agency from 2004 until 2016. Hopefully the results can be a starting point for durability of concrete research in Indonesia.

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