• The KSFM Journal of Fluid Machinery
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• v.15 no.3
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• pp.25-31
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• 2012

A computational study on the improvement of the pressure loss of intake system, which is located at engine manifold of the combat vehicle, has been conducted using a finite-volume-based, Reynolds-Averaged Navier-Stokes (RANS) solver. The computational result of the pressure loss through the air cleaner is in good agreement with equivalent experimental data. A parametric study was done for improving of the pressure loss of intake system over the baseline case. The effects of five primary parameters such as the height of inlet, the width of interconnection pipe, the shape of drain chamber and the diameter of filter housing were considered in this study. Consequently, this computational investigation can contribute to finding an optimal guideline for the idea of improvement in the pressure loss of intake system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.6
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• pp.797-803
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• 2012

In this paper, for minimizing the real-time operating load losses of the power transformer, a SCADA optimum operating system was developed, and the economic analyses on the test operation were performed. Transformer loss DB which reflects the economic integration operation criteria was constructed by referring the transformer manufacturer's loss data(iron loss, copper loss). Based on the loss DB, each substation transformer real-time loss was calculated according to the size of the transformer loads, and if integration or separation transformer operating conditions minimizing the loss are met, then a window pops-up and the dispatcher performs the substation equipments operation according to the procedure provided by this system. With the existing SCADA main program, the relation database of the substation facilities and integration/separation operation algorithm were developed and applied to Auto MTR Processor and pconn Processor Task module. Seven stations test data for seven months were analyzed for the economic analyses, and the results showed that Cost-Benefit ratio was 2.64, and IRR(Internal Rate of Return), 36%, which asserted the economic justification of the proposed system.

• Journal of the Korea Society of Computer and Information
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• v.3 no.2
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• pp.169-175
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• 1998

There is a shared multibuffer method which can preventing HOL blocking in ATM switch. However, the system still has a problem that reduces the performance of the system because of the cell loss. Therefore, in this paper, preventing of cell loss in non-contentional shared multibuffer switch is suggested. To prevent cell loss, a structure is suggested that a cell can be loss in a certain slot time is stored in the dedicated temporary memory so the cell can be transferred in the next slot time. The simulation result of the structure, this suggested system superior performance than the exited system in cell loss rate and throughput.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.421-426
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• 2009

This paper describes on energy loss in a pipe of refuse collecting system. Analysis energy loss in a pipe is the decisive factor in a design for refuse collecting system. From the analysis energy loss, we can determine the capacity of turbo blower. The flow characteristics in the pipe with the refuse bag are analyzed by three-dimensional Navier-Stokes analysis. The refuse bag is modeled using the actual measurement. We obtain friction factor by changing refuse bag's size and mixing ratio and Reynolds number. And From the result we calculate energy loss by using compressible flow analysis.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.45-51
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• 2014

Distribution system is a critical link between customer and utility. The control of power loss is the main factor which decides the performance of the distribution system. There are two methods such as (i) distribution system reconfiguration and (ii) inclusion of capacitor banks, used for controlling the real power loss. Considering the improvement in voltage profile with the power loss reduction, later method produces better performance than former method. This paper presents an advanced evolutionary algorithm for capacitor inclusion for loss reduction. The conventional sensitivity analysis is used to find the optimal location for the capacitors. In order to achieve a better approximation for the current candidate solution, Opposition based Differential Evolution (ODE) is introduced. The effectiveness of the proposed technique is validated through 10, 33, 34 and85-bus radial distribution systems.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.2
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• pp.62-68
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• 2001

It is a serous subject for energy conservation to prevent the energy loss caused by the mixture of heated and cooled air jets in perimeter and interior zone of a building operated with tow kinds of air-conditioning system simultaneously. The purpose of this paper is to clarify the quantitative and qualitative mechanisms of mixing loss and to propose a evaluation method for it. By using the dynamic heat load calculation, heat extraction load of a typical office building in Busan are calculated. According to the results, numerical simulations based on CFD(Computational Fluid Dynamics) were performed in order to evaluate mixing loss in the physical size of HVAC system. Then, the distributions of air temperature and airflow patterns according to the differences of set-point temperature are analyzed to grasp relations how to influence mixing loss.

• Journal of the Korean Data and Information Science Society
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• v.14 no.3
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• pp.631-639
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• 2003

Bayes estimates of reliability for the stress-strength system are obtained with respect to LINEX loss function. A reference prior distribution of the reliability is derived and Bayes estimates of the reliability are also obtained. These Bayes estimates are compared with corresponding estimates under squared-error loss function.

• Journal of Korea Multimedia Society
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• v.16 no.9
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• pp.1067-1076
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• 2013

Known as an important criterion that evaluates performance of future high-speed backbone networks, burst data loss ratio is well-studied in Optical Burst Switching networks. Current literatures mostly focus on reduce burst loss ratio without considering the system stability and link utilization after reducing. In this paper, we propose a novel framework which comes from feedback theoretic to dynamically control burst loss ratio in OBS. The proposed scheme tries to track the pre-set values of burst loss ratio and increases the stability and link utilization degree. The simulation results show that measured burst loss ratio always tracks setup reference with small errors, wavelength channel utilization is increased up to 2% and the system stability is also improved.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1137-1142
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• 2008

In this paper, an effect on power conversion unit in high-speed railway vehicle by loss of contact between a catenary system and pantograph suppling electrical power to high-speed railway vehicle are investigated. One of the most important needs accompanied by increasing the speed of high-speed railway vehicle is reduced that arc phenomenon by loss of contact brings out EMI. in case of high-speed railway vehicle using electrical power, as comparison with diesel rolling stock, PLD(Power Line Disturbance) such as harmonic, transient voltage and current, EMI, dummy signal injection etc usually occur. To analysis the effect on loss of contact, it is necessary electrical modeling system between the contact line and the pantograph according to the loss of contact. Therefore analytical model of a contact line and a pantograph is constructed to simulate the behaviour of loss of contact. The reliability of the modeling system is verified by simulation implementation on kinds of loss of contact.

• Journal of Applied Reliability
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• v.1 no.1
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• pp.35-46
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• 2001

Replacement policy of a degradation system is investigated by incorporating the loss function. Loss function is defined by the deviation of the value of quality characteristic from its target value, which determines the loss cost. Cost function is comprised of the inspection cost, replacement cost and loss cost. Two cost minimization problems are formulated : 1)determination of an optimal inspection period given the state for the replacement and 2)determination of an optimal state for replacement under fixed inspection period. Simulation analysis is performed to observe the variation of total cost with respect to the variation of the parameters of loss function and inspection cost, respectively As a result, parameters of loss function are seen to be the most sensitive to the total cost. On the contrary, inspection cost is observed to be insensitive. This study can be applied to the replacement policy of a degradation system which has to produce the quality critical product.