• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.1260-1262
• /
• 2004

Direct Load Control(DLC) system is a load management program for stablization of electric power supply-demand. It is a series of acts limiting the demand of selected demand side at peak load or other time periods. Recently, power supply-demand instability due to dramatic increase in power usage such as summertime air-conditioning load has brought forecasts of decrease in power supply capability. Therefore heightening the load factor through systematic load management, in other words, Direct Load Control became necessary. By examining the composition and operation of the DLC system, this paper provides conceptional understanding of the DLC system and help in system research.

• Journal of Power Electronics
• /
• v.6 no.2
• /
• pp.114-120
• /
• 2006

This paper compares two types of direct torque controllers for permanent magnet synchronous motors(PMSMs). These controllers both use a single-chip FPGA(Field Programmable Gate Array) but have differing hardware configurations. One of the controllers was constructed by programming a soft-core CPU and hardware logic circuits written in VHDL(Very high speed IC Hardware Description Language), while the other was constructed of only hardware logic circuits. The characteristics of these two controllers were compared in this paper. The results show the controller constructed of only hardware logic circuits was able to shorten the control period and it was able to suppress the low torque ripple.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2006.05a
• /
• pp.59-64
• /
• 2006

In this paper, developed a uninterruptible hotline tools and method for replacement of strain pole crossarm on overhead distribution line. For practical use of developed tools, following direct hot-line methods were proposed: 'Direct hot-line method for replacement of pin pole crossarm', 'Direct hot-line method for alteration of crossarm' and 'Crossarm replacement method in uninterruptible cable displacement area'. These methods were proposed more simple and safe working on hotline job.

• Proceedings of the KIPE Conference
• /
• 2008.10a
• /
• pp.16-18
• /
• 2008

A novel general direct duty ratio pulse width modulation strategy is proposed to modulate matrix converters. By using average concept over one switching period, the modulation algorithm and the required equations are derived to synthesize the desired output voltage and to achieve the controlled input power factor. The proposed method use continuous carrier and the predetermined duty ratio signal for directly generating gating signals an thus is named "direct duty ratio PWM(DDPWM)". The feasibility and validity of the proposed strategy are verified by experimental results.

• Journal of Power Electronics
• /
• v.13 no.6
• /
• pp.1000-1007
• /
• 2013

This paper proposes a sliding-mode-based direct power control (DPC) method in a three-phase boost rectifier without the use of a voltage sensor. This sliding-mode-based DPC is used to improve transient-state response characteristics. This DPC can eliminate voltage sensors by calculating a voltage using a sensorless method, thus considerably reducing cost. This DPC first presents an effective algorithm that does not significantly affect the previous performance and does not need a voltage sensor. Thereafter, the effectiveness of the algorithm is verified by simulations and experiments.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2001.05a
• /
• pp.52-57
• /
• 2001

Laminar two-dimensional time-dependent flow past a circular cylinder is numerically investigated using direct numerical simulation for the low Reynolds number (Re=164∼280). The higher-order finite difference scheme is employed for the spatial distributions along with the second order Adams-Bashforth and the first order backward-Euler time integration. The convection term is applied by the 7th order up wind scheme and the pressure and viscosity terms are applied by the 4th order central difference. The grid system makes use of the regular grid system and it is generated by an equation. The calculated results of drag coefficients, lift coefficients, pressure distributions, and vorticity contours and other information are compared with experimental and numerical ones. These results obtained by the present DNS show good agreement with the previous studies.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.12 no.3
• /
• pp.256-262
• /
• 2012

Direct teaching of the industrial robot is a novel technique to easily teach manipulators. However, teaching data by human hand cannot help having large noise errors ranging from low to high frequency. To use teaching data, post-processing to correct the teaching trajectory is required. Here, a novel shape-based trajectory correction method to rebuild teaching data with the feature information of curvature and velocity is proposed. The proposed method is tested on square and circular objects.

• The Korean Journal of Emergency Medical Services
• /
• v.19 no.2
• /
• pp.29-38
• /
• 2015

Purpose: The purpose of this study was to improve airway management ability by comparing the speed, angle of the neck, and confidence and ease of supraglottic airway laryngopharyngeal tube (SALT) and endotracheal intubation via direct laryngoscopy. Methods: The subjects of this experimental research study with a randomized crossover design were 44 emergency medicine technician - paramedics working in the fire department of 'J' - do. SPSS version 19.0 was used in the statistical analysis. Results: Speed and angle of the neck (p<.001), as well as confidence and ease (p<.001), showed significant differences between endotracheal intubation with a SALT and endotracheal intubation via direct laryngoscopy. Conclusion: If endotracheal intubation via direct laryngoscopy is difficult to use or in trauma patients, using a SALT is safe and enables fast intubation. Moreover, in order to improve the efficiency of advanced airway management, the application of SALT should be introduced in the domestic scene.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.988-992
• /
• 2006

In recent semiconductor manufacturing clean rooms, air washers are used to remove airborne gaseous contaminants such as $NH_3,\;SO_x$ and organic gases from outdoor air introduced into clean room. Meanwhile, there is a large quantity of exhaust air from clean room. It is desirable to recover heat from exhaust air and use it to reheat outdoor air. In the present study, an experiment was conducted to investigate the heat recovery and gas removal efficiencies of a direct atomization type heat recovery air washer.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.05a
• /
• pp.686-689
• /
• 2014

This Paper is about the study that use the IPM(Intelligent Power Module) which is a integrated switching module to drive inverter gates for driving of a multi-pole BLDC(Brushless Direct Current) motors. When designing a inverter using the various manufacturers IPM, it suggests a electronic circuit system to evaluate the electrical and logical characteristics of the IPM with various brands.