• Wind and Structures
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• v.30 no.4
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• pp.379-392
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• 2020

The paper presents a Life-Cycle Cost-based optimization framework for wind-excited tall buildings equipped with Tuned Mass Dampers (TMDs). The objective is to minimize the Life-Cycle Cost that comprises initial costs of the structure, the control system and costs related to repair, maintenance and downtime over the building's lifetime. The integrated optimization of structural sections and mass ratio of the TMDs is carried out, leading to a set of Pareto optimal solutions. The main advantage of the proposed methodology is that, differently from the traditional optimal design approach, it allows to perform the unified design of both the structure and the control system in a Life Cycle Cost Analysis framework. The procedure quantifies wind-induced losses, related to structural and nonstructural damage, considering the stochastic nature of the loads (wind velocity and direction), the specificity of the structural modeling (e.g., non-shear-type vibration modes and torsional effects) and the presence of the TMDs. Both serviceability and ultimate limit states related to the structure and the TMDs' damage are adopted for the computation of repair costs. The application to a case study tall building allows to demonstrate the efficiency of the procedure for the integrated design of the structure and the control system.

• Journal of Biosystems Engineering
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• v.25 no.4
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• pp.265-272
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• 2000

Feasibility of the self-TMR mixing/feeding system for dairy farm in Korea was analyzed by comparing with a traditional feeding system. The total operating cost of self-TMR feeding system decreased with an increase of farm size. However, the cost was higher than that of traditional feeding system because of its high purchasing cost of TMR mixer as an initial investment. Profit per unit input of the TMR feeding system became greater over the traditional system when the farm size is larger than 17 heads due to more and better milk production. The profitable discrepancy became bigger as dairy farm size increases.

• Journal of Korean Society for Geospatial Information Science
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• v.11 no.4 s.27
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• pp.29-34
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• 2003

The purpose of this study is to present the price computation criteria with the aspect of price policy for the geographical information circulation. The price policy is to make activated circulation for geographical information. The price policy of this research considered the supplier and the user side at the same time. Important issue of price policy is that initial cost for system development calculate burying cost, and preservation and renewal cost charge to user. Distribution cost of geographical information charge to user according to use media, and apply differential rates of cost according to the purpose of using, up-to-dateness of data. Also, present the price policy that must apply copyright fee to of offer geographical information. Consider various terms that was studied in this study, the price computation criteria was presented. Through this, it is expected that geographical information circulation is activated more.

• Journal of Korean Society for Quality Management
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• v.46 no.4
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• pp.821-842
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• 2018

Purpose: To derive key requirements and key technologies for weapon system acquisition business by using Qualify Function Deployment (QFD), and to reduce business cost by setting the target performance and key expense of weapon system. Methods: We propose a QFD methodology that can induce rational decision-making by translating analyst's subjective opinions into quantitative values when analyzing requirements at the initial stage of weapon system development project. Based on QFD methodology, QFD application model combining house of quality, value engineering, and analogy cost estimating technique is presented. Results: It was possible to analyze the specific requirements necessary for the development of the weapon system, to solve the communication problem of the participants, to set clear development direction and target. Conclusion: By applying the QFD application model at the early stage of the weapon system acquisition project, it is possible to reduce the business cost by establishing clear development direction and goal through the procedural analysis process.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.11
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• pp.81-87
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• 2018

Among various types of geothermal heat pump systems, Vertical Closed-Loop Geothermal Heat Pump (VGSHP) has received increasing attention due to a variety of advantages such as the potential to be installed in a relatively small space and improved energy efficiency. In this research, the performance of VGSHP system coupled with heat storage tank was evaluated, by analyzing operational behavior of heat storage tank, the variations of heat pump energy performance due to the connection with heat storage tank, part load ratios characteristics of heat pump and the corresponding energy cost, compared to chiller and boiler based conventional system. The results of this study showed that the VGSHP system coupled with heat storage tank showed an energy saving effect of about 18% for cooling and about 73% for heating, and annual heating/cooling energy cost reduction of 43,000,000 KRW ($ 39,000), compared to the conventional air conditioning system. In addition, after considering both energy cost and initial investment cost including equipment, installation and auxiliary device expenses, payback period of approximately 11.8 years was required.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.284-293
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• 2002

Using the life cycle cost concept, optimum maintenance and retrofit planning for reliable seismic performance is suggested the overall life cycle cost to be minimized including the initial cost, the costs of inspection, repair, and failure. Limit states of the bridges are defined. And failure probabilities are computed through crossing theory. The effect of maintenance and retrofit is represented using the probability of damage detection and event tree analysis. Optimization of maintenance and retrofit planning method proposed from this research was applied to numerical examples. The analysis incorporates the acceleration and site conditions prescribed in the code, and the quality of inspection methods.

• Industrial Engineering and Management Systems
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• v.3 no.2
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• pp.100-115
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• 2004

The network representation and branch and bound algorithm with efficient lower and upper bounding procedures are developed to determine a global optimal production schedule on a machine that minimizes sequence-dependent setup cost and earliness/tardiness penalties. Lower bounds are obtained based on heuristic and Lagrangian relaxation. Priority dispatching rule with local improvement procedure is used to derive an initial upper bound. Two dominance criteria are incorporated in a branch and bound procedure to reduce the search space and enhance computational efficiency. The computational results indicate that the proposed procedure could optimally solve the problem with up to 40 jobs in a reasonable time using a personal computer.

• Journal of information and communication convergence engineering
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• v.10 no.4
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• pp.349-358
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• 2012

Over a wireless sensor network (WSN), accurate localization of sensor nodes is an important factor in enhancing the association between location information and sensory data. There are many research works on the development of a localization algorithm over three-dimensional (3D) space. Recently, the complexity-reduced 3D trilateration localization approach (COLA), simplifying the 3D computational overhead to 2D trilateration, was proposed. The method provides proper accuracy of location, but it has a high computational cost. Considering practical applications over resource constrained devices, it is necessary to strike a balance between accuracy and computational cost. In this paper, we present a novel 3D localization method based on the received signal strength indicator (RSSI) values of four anchor nodes, which are deployed in the initial setup process. This method provides accurate location estimation results with a reduced computational cost and a smaller number of anchor nodes.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.774-778
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• 2008

The inaccuracy of inertial sensors used in low cost IMU's limits the usage to ARS, at best. Sensor fusion technologies are widely used to overcome this problem. GPS is the most popular secondary sensor, but GPS alone cannot fully compensate the IMU errors in the initial alignment process and rectilinear flights. This paper presents a new concept of aiding the low cost IMU with the sun line of sight vector. The simulation and experimental results in this paper proves that aiding of INS/GPS with the sun line of sight vector increases the observability and improves accuracy remarkably.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.8
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• pp.374-379
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• 2000

The nodal marginal cost and the congestion charge are used as the econimic signals for the electricity price and new invetments in deregulated power systems. In this paper, the nodal marginal cost and the congestion charge are calculated by using the shadow prices resulted from the calculation of Optimal Power Flow(OPF). Linearization of inequality constraints and piecewise linear cost functions make an OPF problem LP-based forms. In order to use the shadow price, the Interior Point(IP) algorithm is applied as a solution technique to the formulation. This paper proposes an algorithm to determine efficients initial points which are guaranteed to be interior points.