• Korean Journal of Construction Engineering and Management
• /
• v.5 no.6 s.22
• /
• pp.245-254
• /
• 2004

Pre-compensation and post-construction policy'(PCPC) is a part of $\ulcorner$public project performance improvement policies (PPPIP)$\lrcorner$ whose purpose is to reduce the construction project cost by $20\%$. This research focuses on measuring the quantitative and qualitative impacts of PCPC public construction project. The evaluation of PCPC was conducted using five performance indices which are measuring performance improvement in terms of project cost and schedule. The analysis results show that implementation of this policy reduced $4.8\%$ of public construction project budget while playing a positive role in shortening the project schedule.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.5
• /
• pp.611-616
• /
• 2018

In the cost based pool market in Korea, there is no compensation of reactive power because the fuel cost for reactive power is relatively low compared to that of active power. However, the change of energy paradigm in the future, such as widespread integration of distributed renewable energy source, will prevent the system operator from mandating the reactive power supply without any compensation. Thus, in this study, we propose the reference voltage of the 345 kV transmission system that minimizes the reactive power supply. This is closely related to the economic dispatch of reactive power aiming at minimizing the compensation cost for the reactive power service. In order to verify the effectiveness of the proposed reference voltage, the simulations are performed using the IEEE 14 bus system and the KEPCO real networks. The simulation results show that a voltage lower than the current reference value is recommended to reduce the reactive power supply and also suggest that the current voltage specification for the 345 kV system needs to be reviewed.

• Proceedings of the KIPE Conference
• /
• 2000.07a
• /
• pp.317-320
• /
• 2000

This paper proposes a voltage compensation method to improve the control performance of B4 inverter which is studied for low-cost drive systems. The B4 inverter employs only four switches and it has a center-tapped connection in the split dc-link capacitors to one phase of a three-phase motor. In the B4 topology unbalan-cd three-phase voltages will be generated by the dc link voltage ripple. To solve this problem we present a voltage compensation method which adjusts switching times considering dc link voltage ripple. The proposed method is verified by simulation results,

• Proceedings of the KIPE Conference
• /
• 2000.07a
• /
• pp.133-136
• /
• 2000

Current Source Inverter(CSI) operated in square wave mode is more efficient than the PWM CSI because of increased cost greater complexity of control algorithm, and substantial switching losses EMI. But the square wave output current of CSI rich in low order harmonics produce motor torque ripples. Therefore in this paper describes the active power filters for square wave current compensation of current source induction motor. Also extended current synchronous detection(ECSD) as compensation algorithm is proposed. To confirm the validity o proposed system some simulation results are presented and discussed.

• Journal of the Korean Society of Safety
• /
• v.13 no.3
• /
• pp.143-162
• /
• 1998

There are two ways to prevent labor from Industrial accident One is pre-prevention, another is compensation. Onless It happens the compensation problem from The pre-prevention, It will be best way to solve. To prevent lobar widely first, the application range should be wide which is base of repayment second, assoradiy to reconsideration of apportionment properly The Max-Min limitative cost of compensative should be paid, one the other hands, The lay-off payment of limitative and The fixed payment of Funeral should be introduce Third, The specialization of examination.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2005.10a
• /
• pp.47-52
• /
• 2005

This paper describes how a relatively compensate the error of position by using low cost Inertial Measurement Unit (IMU) has been evaluated and compared with the well established method based on a Kalman Filter(KF). The compensation algorithm by using IMU have been applied to the problem of integrating information from an Inertial Navigation System (INS). The KF is to estimate and compensate the errors of an INS by using the integrated INS velocity and position. We verify the proposed algorithm by simulation results.

• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.8-10
• /
• 2005

In a general purpose inverter, a dead-time compensation strategy is very important for reducing torque ripples and acoustic noises of motors. However, in the case of small capacity inverter, the accurate dead-time compensation is hard to be obtained because a removal of the switching noise in a feedback current signal is difficult on condition of low-cost implementation. In this paper, the operation characteristics of the general purpose inverter applied the dead time compensation algorithm using an instantaneous back calculation of the phase angle of the current are presented.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.413-416
• /
• 2007

Motion-estimation/motion-compensation (ME/MC) provides superior motion picture quality but its huge computation load results in high cost. Impulsive driving is a cost-effective solution but it suffers from large flicker and brightness loss. Motion compensated impulsive driving technology has been developed to achieve high motion picture quality in a cost-effective implementation by combining ME/MC and impulsive driving. The key idea is to apply ME/MC or impulsive driving selectively according to the motion vector distribution of the incoming image sequence. In this paper, the description of the algorithm and the experimental results are provided.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.5
• /
• pp.661-666
• /
• 2015

This paper proposes a method for solving running cost problem by minimizing switching reactive power compensation devices. An objective function was modeled by calculating the weighting value of cost, and a solution was derived using ILP. This paper suggests optimal coordinative control method between FACTS, Shunt Reactors, Capacitors and OLTC. Therefore, it is valuable for decision maker in determining order and capacity of devices which gaining a voltage stabilization. As a result, the objectives of voltage stabilization and cost minimization were achieved simultaneously. This realizes the economic efficiency of the system. We start by showing how to solve systems of linear equations using the language of pivots and tableaus. The effectiveness of this technique is demonstrated in modified PSS/E MIGUM 45 bus system. The simulation results show the effectiveness of this algorithm by comparing the outcome withseveral established methods.

• Journal of the Korean Society for Precision Engineering
• /
• v.11 no.4
• /
• pp.158-164
• /
• 1994

A volumetric error compensation method was stueide with measuring systematic error of a Coordinate Measuring Machine(CMM). The volumetric error equations were proposed for a Moving Bridge type CMM. Using the error equations, error vectors in the measuring volume were corrected by a software method. The CMM was controlled by the compensation program separately in the measuring and moving function of the CMM proving. The linear accuracy of the CMM was measured by the Laser Interferometer and compared with the data before the volumetric error compensation. This method was proved as low cost and effective to reduce the systematic error of the CMM, as no hardware modification is required.