• Journal of the Korea Safety Management & Science
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• v.13 no.1
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• pp.121-126
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• 2011

The provisions regarding the standard cost for recycling stated under the Extended Producer Responsibility (EPR) since 2002, include different and complicated obligatory steps to be taken on a variety of subject items regarding the collection, the transportation and the treatment, making the corporations face in their calculating and executing the standard cost. This study presents more objective calculation scope and standard for the purpose of efficient operation of the standard cost for recycling, in consideration of the general industry perception toward cost issue as well as domestic/overseas case studies regarding the standard cost for recycling. Besides, the study presents the checking items and the calculation contents per step to calculate the standard cost for recycling. Therefore, it is expected not only to be used as the objective standard to calculate the standard cost for recycling, but also to contribute to increasing the work efficiency in the following ongoing re-calculation process and to maintaining the consistent operation of the institution.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.640-648
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• 2022

In the United States, the Safety Rest Areas (SRAs) were introduced as highway roadside infrastructures in the early 1900s. The State Departments of Transportation (DOTs) operate/maintain their SRAs using different methods. The Washington DOT used the in-house workforce method for over 20 years, whereas some states moved to Performance-Based Contracting (PBC) from the in-house workforce to save cost primarily. Several existing studies claimed that using the PBC approach saved costs on several highway assets. Thus, the principal objective of this study is to compute and compare the unit operating/maintenance cost of SRAs using the in-house workforce method (in Washington state) with the PBC approach (in other states). The findings of this study show that the average annual cost using the PBC approach was much more than the average annual cost using the in-house workforce approach. The findings also show that in Washington state, the 'Labor Cost' category was a key expenditure, which is statistically higher than other categories. The 'Labor Cost' was followed by the 'Other Services', and then 'Materials and Supplies' and 'Equipment.' The study's findings indicated that outsourcing does not always save costs for agencies. The study findings may help transportation construction/maintenance professionals select a cost-effective approach for their future planning.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.50-56
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• 2022

Change Orders generally impact cost and schedule performance of highway projects. However, highway projects that do not have any change orders also face cost growth and schedule delays. This study seeks to determine the cost and schedule performance of Texas DOT projects by collecting project data for 120 highway projects completed between 2016 to 2020. For the study, we selected project data that has zero or negative change orders which were then grouped and analyzed based on their Project Types i.e., maintenance works; structural works; restoration and rehabilitation works; and safety works. The study found that performance of Maintenance and Safety type projects had less cost and schedule growth among the data analyzed. Statistical tests also found that even though the projects have no change orders, Rehabilitation and Restoration type projects experienced significant schedule growth compared to others. However, the data did not show any significant cost and schedule growth for the projects when statistical tests were performed on overall data. The study concluded that highway projects are experiencing schedule growth even though the projects had no change orders. Results from the study can help planners, engineers, and administrators to gain better insight on how different types of highway projects are performing in terms of cost and schedule and eventually derive appropriate solutions to minimize cost and schedule growth in such projects.

• Steel and Composite Structures
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• v.13 no.1
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• pp.47-70
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• 2012

To enhance cable stiffness, this paper proposed a combined application of carbon fiber reinforced polymers (CFRP) and steel materials, resulting in a novel type of hybrid stay cable system especially for the cable-stayed bridges with main span lengths of 1400~2800 m. In this combination, CFRP materials can conserve all their advantages such as light weight and high strength; while steel materials help increase the equivalent stiffness to compensate for the low elastic modulus of CFRP materials. An increase of the equivalent stiffness of the hybrid stay cable system could be further obtained with a reasonable increase of its safety factor. Following this concept, a series of parametric studies for the hybrid stay cable system with the consideration of stiffness and cost were carried out. Three design strategies/criteria, namely, best equivalent stiffness with a given safety factor, highest ratio of equivalent stiffness to material cost with a given safety factor, and best equivalent stiffness under a given cost were proposed from the stiffness and cost viewpoints. Finally, a comprehensive design procedure following the proposed design strategies was suggested. It was shown that the proposed hybrid stay cable system could be a good alternative to the pure CFRP or traditional steel stay cables in the future applications of super long span bridges.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.696-702
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• 2007

The purpose of this paper is to analyze cost-effectiveness of a train simulators. The cost-effectiveness of training program is assessed by multiplying transfer effectiveness ration(TER) by training cost ration(TCR). If their product is less than one, the program is not cost effective. Even if a program is not cost effective, however, safety considerations may be important to consider.

• Journal of the Korean Society of Safety
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• v.25 no.6
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• pp.115-122
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• 2010

The importance of the life cycle cost (LCC) analysis for bridges has been recognized over the last decade. However, it is difficult to predict LCC precisely since the costs occurring throughout the service life of the bridge depend on various parameters such as design, construction, maintenance, and environmental conditions. This paper presents a methodology for the optimal life cycle cost design of a bridge. Total LCC for the service life is calculated as the sum of initial cost, damage cost, maintenance cost, repair and rehabilitation cost, user cost, and disposal cost. The optimization method is applied to design of a bridge structure with minimal cost, in which the objective function is set to LCC and constraints are formulated on the basis of Korean Bridge Design Code. Initial cost is calculated based on standard costs of the Korea Construction Price Index and damage cost on damage probabilities to consider the uncertainty of load and resistance. Repair and rehabilitation cost is determined using load carrying capacity curves and user cost includes traffic operation costs and time delay costs. The optimal life cycle cost design of a bridge is performed and the effects of parameters are investigated.

• Journal of the Korea Safety Management & Science
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• v.3 no.3
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• pp.77-86
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• 2001

An operational strategy for inventory control on finished goods in the distribution system has been given attention to many enterprises and many studies regarding this field have been done and is also on-going currently. Many of these studies represented a large scale distribution network with a unified formulation by using defined symbols. These methods have provided the systematic approach of the distribution network but they are impossible to applying the reality system due to not considering the service rate of demand and treating the shortage of inventory. In order to overcome these unrealistic problems, the novel safety stock policy of responding to customers' inventory distribution network is suggested. this paper explores the transportation between Central Distribution Center(CDC) and Regional Distribution Center(RDC). Especially, the relation of transportation cost between CDC and RDC and cost of inventory control according to safety inventory with service level are emphasized. We could obtain the good results of this study by determining the optimal safety stock considering the various variables and constraints.

• Journal of the Korea Safety Management & Science
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• v.3 no.2
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• pp.73-89
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• 2001

Safety management cost, US$ one thousand billion has been input to the construction area from 1995 to 2000 but the management quality is still in the developing country level. The above mentioned increase of accident rate are attributed to the generous code regulation, net fit to the sense, varying with time change, but the more fundamental reason of this is no practical construction safety management system, up to now. Hardware-orienting operation for the system could be a main reason of this problem. In this paper, we developed a model for efficent construction safety system. It was found from the case study that the model result in high efficient with low cost.

• International Journal of Safety
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• v.8 no.2
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• pp.1-4
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• 2009

Various falling prevention systems with vertical guided rail have been supplied in order to prevent falling accidents and acquire the long life and cost down for the maintenance. Almost the imported system is composed of a guided rail and the comfort components. It has the mechanism that cannot be dismounted from the guided rail at the accident site. Thus, the aim of this study is to develop a falling prevent system that has a direct dismounting function, which can release easily from the falling accident point. This system has a high durability and robust. And the cost efficiency of the system and safety for workers also are improved remarkably. From the results, we showed the proposed new falling system is sufficiently safety and satisfies the KOSHA regulation through the numerical stress analysis. Also it is expected as the useful and effective safety device for workers.

• Journal of the Korean Society of Safety
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• v.14 no.2
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• pp.155-162
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• 1999

reliability from components reliability. In this case, it assumes that components failure is mutually independent, but it may not true in real systems. In this study, the mean cost per unit time is computed as the ratio of mean life to the mean cost. The mean life is obtained by the reliability function under power rule model. The mean cost is obtained by the mathematical model based on the inspection interval. A heuristic method is proposed to determine the optimal number of redundant units and the optimal inspection interval to minimize the mean cost per unit time. The assumptions of this study are as following : First, in the load-sharing k-out-of-n:G system, total loads are applied to the system and shared by the operating components. Secondly, the number of failed components affects the failure rate of surviving components as a function of the total load applied. Finally, the relation between the load and the failure rate of surviving components is set by the power rule model. For the practical application of the above methods, numerical examples are presented.