• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.837-842
• /
• 2007

Information storage devices using disks have a disk vibration at the frequency which is equivalent to the disk rotational speed. They also have a track vibration due to the disk eccentricity at the same frequency. In near field recording systems, the former affects the air-gap servo and the latter affects the tracking servo. In this paper, we introduce a novel control algorithm based on the internal model principle to both servos. A controller block designed by the principle is connected to the base lead-lag type compensator in parallel in order to cancel the repeatable run-out due to the disk vibration or eccentricity. Simulation and practical application of the algorithm on a near field recording system show good servo performance.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• v.11 no.1
• /
• pp.31-34
• /
• 2006

Purposes of this research are convenience of manufacture, quality sophistication and reduction of a/s' ratio by that improve several shortcomings of existing steel housing The Housing of head is changed existent steel housing to ABS (acrylonitrile butadiene styrene) copolymer housing and its shape is changed. It does not need that paint housing by paint. so We may not care scar at storage or manufacture. The fast work speed and A/S is possible by combining a safety plate and a housing by volt and spring washer. When disjoint head part, there is no damage of safety plate and housing. Noise is disappeared by resonance phenomenon in early rpm at motor moving. When neck part of housing and a middle pipe are connected by drill nasa, the work is easier Also, there is sense of security little more catching motor in housing The improvement accomplished much improvements including light weight of head part.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.3
• /
• pp.26-36
• /
• 2010

This paper provides a description of the combustion model to obtain an accurate dynamic engine phenomena that satisfies real-time simulation for model-based engine control. The combustion chamber is modeled as a storage device for mass and energy. The combustion process is modeled in terms of a two-zone model for the burned and unburned gas fractions. The mass fraction burnt is modeled in terms of a Wiebe function. The instantaneous net engine torque is calculated from the engine speed and the instantaneous piston work. The modeling accuracy has been tested with a cylinder pressure data on a test bench and also the ability of real-time simulation has been checked. The results show that combustion model yields sufficiently good performance for the model-based control logic design. However the influence factors effected on model accuracy are some room for improvement.

• Journal of Urban Science
• /
• v.7 no.1
• /
• pp.55-61
• /
• 2018

Long bridges, such as suspension bridges and diagonal bridges, are complex phenomena that show different behaviors depending on the shape and rigidity of the cross sections, such as wind vibrations and liquid vibrations from earthquakes in liquid storage containers. This is called the lower skirt on the lower side of the bridge, and the installation of lower skirt is effective for release and vortex vibrations caused by rapid winds, and that increases the stability of the wind resistance of the bridge. Optimal shape and installation of the lower skirt is also essential to make maximum wind speed effect of the lower skirt. Therefore, this study proposes a numerical analysis method to control the vibration of a bridge by calculating the optimal installation angle of an optimal lower skirt according to the optimal control theory and this study evaluates the impact on the optimal control system by minimizing the dominance equation with an evaluation function,which is an indicator for evaluating the optimal control theory state.

• International Journal of Contents
• /
• v.9 no.1
• /
• pp.11-17
• /
• 2013

Recently, online real-time web accessible mobile devices such as smartphones, tablet PCs and application services have been developing rapidly. Hospitals also need to adopt an efficient information system that can provide decent medical services under mobile computing environments to complete future medical services. This study proposes a system in which a doctor can examine a patient and make out a prescription in a ward on a real-time based on the current Order Communication Systems (OCSs) through mobile interfaces. The proposed system implements mobile web pages using HTML5, instead of a mobile app. Web processing speed can be enhanced using the web socket and web storage functions of HTML5.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.5B no.1
• /
• pp.84-89
• /
• 2005

This paper presents a control algorithm for a large salient-pole synchronous motor fed by a Load Commutated Inverter (LCI). Many papers have been presented in the past few years on the justification, design, and application of variable-speed drive. The focus of this paper is on high torque operation and the estimation of initial rotor position. The results of simulation indicate that it is possible to produce the maximum torque and estimate the initial rotor position.

• Proceedings of the KIEE Conference
• /
• 2000.07a
• /
• pp.150-152
• /
• 2000

This paper introduces an advanced three-phase load flow analysis algorithm in the radial distribution network. This method is an extension of the Novel method for solving radial distribution networks with the emphasis on expanding from single phase to three-phase. The proposed method involves only simple algebraic computation without any form of Jacobian matrix but has a desirable convergence characteristic. Computationally, The suggested technique is very efficient and requires less computer memory storage and maintains high execution speed. Also, the submitted process can be easily programmed and be simply extended to different types of load characteristics. A simulation results applied to the IEEE 34 bus radial distribution feeder are examined by using the MATLAB.

• Proceedings of the KIEE Conference
• /
• 2000.07a
• /
• pp.46-48
• /
• 2000

Continuation power flow has been developed to remove the ill-condition problem caused by singularity of power flow Jacobian at and near steady-state voltage instability point in conventional power flow. When solving large-scale power transmission systems, an alternative strategy for improving computational efficiency and reducing computer storage requirements is the decoupled power flow method, which makes use of an approximate version of the Newton-Raphson procedure. This paper presents a technique to improve the speed of continuation power flow system using decoupled power flow method.

• Proceedings of the KIEE Conference
• /
• 2006.10c
• /
• pp.509-511
• /
• 2006

According to the progress of multimedia technology and growth of high speed network, plenty of multimedia contents are produced and in circulation. Because of these reasons, it is required that the method which can manage efficiently and make multimedia contents, for which are saved in Storage as different used, synchronize. In this paper, the metadata schema that can manage the method with being database using each Device metadata that are produced by extracting the needed information to multimedia contents is suggested. And the method that can make synchronized multimedia contents metadata on connecting between heterogeneous devices is proposed.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.27 no.8
• /
• pp.1201-1210
• /
• 1990

This paper proposes on-chip instruction and data cache memories on RISC reduced instruction set computer) architecture which supports fast instruction fetch and data read/write, and enables RISC processor under research to obtain high performance. In the execution of HLL(high level language) programs, heavily used local scalar variables are stored in large register file, but arrays, structures, and global scalar variables are difficult for compiler to allocate registers. These problems can be solved by on-chip Instruction/Data cache. And each cycle of instruction fetch, pad delay causes the lowering of the processors's performance. Cache memories are designed in CMOS technology and SRAM(static-RAM), that saves layout area and power dissipation, is used for instruction and data storage. To speed up and support RISC processor's piplined architecture efficiently, hardwired logic technology is used overall circuits i cache blocks. The schematic capture and timing simulation of proposed cache memorises are performed on Apollo DN4000 workstation using Mentor Graphics CAD tools.