• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.2 s.93
• /
• pp.194-198
• /
• 2005

A novel ultra wideband microstrip-fed circular patch antenna having band stop characteristic in UNII band is presented. The band stop characteristic is realized by inverted-U shaped slot. The range of stop bandwidth can be adjusted by changing the length of the slot. The measured impedance bandwidth of the proposed antenna is from 2.9 GHz to 12.1 GHz with the stop band from 4.9 GHz to 6 GHz for VSWR<2. This antenna shows a monopole-like radiation pattern and flat gain characteristic throughout the operating frequency band.

• Proceedings of the KIEE Conference
• /
• 2006.07a
• /
• pp.218-219
• /
• 2006

This paper is about modeling on 1500V DC electric railroad system. Electric railroad systems have peculiar characteristics against other electric system. The characteristics arc that the railroad systems have electric vehicle loads which are power-varying and location-varying with time. Because of this load characteristic, the electric railroad system modeling which reflects its own characteristics on EMTDC simulation could not be achieved. However, to reflect load characteristic on EMTDC, this paper suggests electric railroad system modeling by using TPS (Train Performance Simulator) that was developed in Korea Railroad Research Institute. A TPS program has various kinds of input data, such as operation condition, vehicle condition, and power system condition. By these data, TPS calculates mechanical power consumption and location, especially it decide electric power consumption on the basis of the fact that consumed electric and mechanical power are equal. Moreover, on this paper, movement of vehicle is reflected on EMTDC simulation as variation of feeder impedance. Also, an electric vehicle load is modeled as time-varying constant power load model.

• Journal of Acupuncture Research
• /
• v.19 no.6
• /
• pp.12-23
• /
• 2002

Objective : Assuming That the Characteristic of Meridian System Has been Similar to This of Electric Potentials in Human Body And that Measurements of Electric Potential at Well(井穴) and Sea(合穴) Points in Branches of the Twelve Meridians(WSBTM) Will Be Representative of Measurements of the Twelve Meridians, to Measure the Electric Potentials of 21 Patients with Shoulder Lesions, And Aching of Shoulder and Arm(肩臂痛)(ASA), to Be Differences in Electric Potentials of Patients Between Before And After Acupuncture Treatment, And Then to Find out the Characteristic of Meridian System in Patients with Shoulder Lesions. Methods : Electric Potentials of Well And Sea Points in the Meridians in Twenty one Patients with ASA Diagnosed by Both x-ray And Self View on Pain at Shoulder And Arm were Repeatedly Measured by Physiograph(PowerLab) at Before And after Acupuncture Treatment, Respectively. Measurements of Those Electrical Potentials Were Analyzed by Factor Analysis. Results : The Electric Potentials of WSBTM At the Left Side Before Acupuncture Treatment Were Divided Into Five Factors, But Those After Acupuncture Treatment Were Done Into Four Factors. On The Other Hand Those At the Right Side Before Acupuncture Treatment Were Divided Into Four Factors, The Number of Factors After Acupuncture Treatment Was Five. Conclusions : In Conclusions, The Number of Factors Before Acupuncture Treatment Are Different from Those After Acupuncture Treatment. In the Results The Effect of Acupuncture Treatment May be Reflected in Measurements of Electric Potential at WSBTM.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.3
• /
• pp.520-525
• /
• 2016

In this paper, Characteristic of power conversion unit of a railway vehicles according to contact loss in feeding system that applied impedance of rigid conductor is analyzed. It applied impedance of rigid bar in modeling of electric railway system. Railway vehicles are performed of modeling based on the performance of the electric railway vehicle. Effects of the contact loss in the power conversion unit were analyzed via main transformer of railway vehicle, the input and output voltage characteristics of the converter through contact loss was generated after linking the vehicle with feeding system.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.6
• /
• pp.1276-1282
• /
• 2013

This paper proposes a stochastic modeling of plug-in electric vehicles (PEVs) distribution in power systems, and analyzes the corresponding clustering characteristic. It is essential for power utilities to estimate the PEV charging demand as the penetration level of PEV is expected to increase rapidly in the near future. Although the distribution of PEVs in power systems is the primary factor for estimating the PEV charging demand, the data currently available are statistics related to fuel-driven vehicles and to existing electric demands in power systems. In this paper, we calculate the number of households using electricity at individual ending buses of a power system based on the electric demands. Then, we estimate the number of PEVs per household using the probability density function of PEVs derived from the given statistics about fuel-driven vehicles. Finally, we present the clustering characteristic of the PEV distribution via case studies employing the test systems.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.956-957
• /
• 2015

This paper analyzes a operating characteristic for maximum power point tracking (MPPT) of photovoltaic generation system. MPPT methods are used to maximize PV array output power by tracking maximum power point(MPP) continuously. To increase the output efficiency of PV system, it is important to have more efficient MPPT. MPPT algorithm is widely used the control method such as the perturbation and observation(PO) method, incremental conductance(IC) method and constant voltage(CV) method. In case of the radiation is changed, this paper proposes a response characteristic with MPPT control algorithms. Also, it proposes the direct for a novel MPPT control algorithm development through the analyzed data, hereby proves the effectiveness of this paper.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.950-951
• /
• 2015

This paper proposes MPPT control considering temperature characteristic of PV module. Conventional CV(Constant Voltage) and PO(Perturbation and Observation) methods have the weak problem about the insolation and temperature change. Thus, in this paper, in order to improve this problem, the optimal voltage and current is determined and the MPPT control is performed. MPPT algorithm proposed in this paper analyze the performance about insolation and temperature change and proves the validity.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.33 no.8
• /
• pp.629-634
• /
• 2009

In this paper, drying mechanism is analyzed for improving the energy efficiency of an electric clothes dryer which consumes more electric power than other appliances. For the purpose, characteristic curves of the dryer such as temperature, relative humidity, evaporation rate, mass transfer coefficient, remaining moisture content curves are experimentally obtained. Based on the experimental results and analysis of drying mechanism, the effect of power of a heater and heat loss on the power consumption of an electric clothes dryer are systematically presented. These results demonstrate the feasibility of controlling heat loss at the heater as well as the backduct component to decrease the power consumption of an electric clothes dryer.

• Proceedings of the KSME Conference
• /
• 2008.11b
• /
• pp.2262-2267
• /
• 2008

In this paper, drying mechanism is analyzed for improving the energy efficiency of an electric clothes dryer which consumes more electric power than other appliances. For the purpose, characteristic curves of the dryer such as temperature, relative humidity, evaporation rate, mass transfer coefficient, remaining moisture content curves are experimentally obtained. Based on the experimental results and analysis of drying mechanism, the effect of power of a heater and heat loss on the power consumption of an electric clothes dryer are systematically presented. These results demonstrate the feasibility of controlling heat loss at the heater as well as backduct component to decrease the power consumption of an electric clothes dryer.

• 한국초전도학회:학술대회논문집
• /
• v.11
• /
• pp.76-76
• /
• 2001