• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.9 no.4
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• pp.164-167
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• 2010

In this paper, an artificial transmission line of triangular-patch type with slots is proposed. This artificial transmission line is useful for miniaturizing the electrical lengths of conventional transmission lines. Also, this structure is easy to regulate the characteristic impedance and electrical lengths. The electrical lengths and the characteristic impedances of the proposed artificial transmission line with some parameters are researched and summarized The proposed artificial transmission line could be useful for compact designs for most of the passive microwave components. The optional-artificial transmission line is fabricated and measured at 2.45GHz.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.1
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• pp.49-54
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• 2016

There is needed the quard channel triple wave lengths pyroelectric infrared flame detector to recognize the unique characteristics of fire sources in various type. This system detects the triple wave lengths of infrared flame emitting maximum radient energy and scattering frequency of flame. The quard channel infrared flame detector detects the duplicate wave lengths of maximum radient energy to enhance the accuracy of detecting fire. Especially this paper focuss on development of the self diagnosis function system including contamination, temperature and input voltage. Therefore, the prevention and early suppression of fire is available.

• Transactions on Electrical and Electronic Materials
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• v.12 no.3
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• pp.93-97
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• 2011

In this paper, we discuss design considerations for an n-channel metal-oxide-semiconductor field-effect transistor (MOSFET) with a lateral asymmetric channel (LAC) doping profile. We employed a 0.35 ${\mu}M$ standard complementary MOSFET process for fabrication of the devices. The gates to the LAC doping overlap lengths were 0.5, 1.0, and 1.5 ${\mu}M$. The drain current ($I_{ON}$), transconductance ($g_m$), substrate current ($I_{SUB}$), drain to source leakage current ($I_{OFF}$), and channel-hot-electron (CHE) reliability characteristics were taken into account for optimum device design. The LAC devices with shorter overlap lengths demonstrated improved $I_{ON}$ and $g_m$ characteristics. On the other hand, the LAC devices with longer overlap lengths demonstrated improved CHE degradation and $I_{OFF}$ characteristics.

• Journal of Advanced Navigation Technology
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• v.21 no.3
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• pp.287-293
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• 2017

This paper describes an unequal Bagley divider using uniform transmission lines with adjustment electrical lengths between output ports. To obtain an arbitrary dividing ratio of Bagley divider, we have only adjusted the electrical lengths of the transmission line between output ports. All the transmission lines have the same characteristic impedance value. This design method does not require an impedance transformer for port matching. For verification, we simulated and fabricated a 3-way, 1:2:1 and 5-way, 2:3:4:3:2 ratio Bagley divider with an operating frequency of 2 GHz. The experimental results are in agreement with the simulated results.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.1
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• pp.1-8
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• 2003

Generally, thrust force of double-sided LPM is more powerful than that of single-sided LPM. Also, double-sided LMP can be effectively applied to the high-precision position system with its simple control scheme. However, An equality between two airgap lengths Is a necessary condition for its high performance. If a little difference between two airgaps is existed, unbalanced normal force and undesirable vibration will be generated. Additionally, even though two airgap lengths are absolutely same, undesirable vibration can be generated because the direction of instantaneous normal force on mover is changed according to excitation methods. An effect of inequality of two airgap lengths is presented in this paper. Distribution of airgap permeance vs. relative displacement is analyzed by two dimensional finite element method. Excitation From this results, current waveforms to reduce the undesirable vibration is proposed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.12 no.1
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• pp.69-74
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• 1999

We have investigated that the high pretilt angle of the NLC, 4-n-pentyl-4-cyanobiphenyl (5CB), was observed on rubbed polythiophene (PTP) surfaces with alkyl chains with more than 10 carbon atoms; it is attributed to the surface-excluded volume effect by the alkyl chain lengths between the LCs and the PTP surfaces. Next, we investigated that the odd-even effect of the polar anchoring strength in 5CB on rubbed PTP surfaces with alkyl chain lengths has been successfully evaluated. The anchoring strength of 5CB for rubbed PTP surfaces with odd-number is weak compared with even-number up to the 6 carbon atoms in the alkyl chain; however, odd-number is strong compared with even-number above 7 carbon atoms. The weak anchoring strength of 5CB is approximately $1\times10^{-3} (J/m^2$) on rubbed PTP surface with 7 carbon atoms; it is relatively strong anchoring strength. Consequently, we conclude that the odd-even effects of the polar anchoring strength in NLCs are strongly related to the characteristics of the polymer and observed clearly for short alkyl chain lengths.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.2
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• pp.93-102
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• 2016

PURPOSE: The purpose of this study is to evaluate the functional effects of action observation plus functional electrical stimulation (FES) treatment on the weight distribution indexes (heel and toe; right and left), stability indexes, gait velocities, and stride lengths of stroke patients. METHODS: The subjects, who were all more than six months post stroke, were randomly divided into two groups of ten each: an experimental group and a control group. TETRAX (Tetrax Interactive Balance System) and GAITRite (GAITRite$^{TM}$ computerized gait analysis system) were measured at baseline, six weeks after treatment. Participants in both the groups received functional electrical stimulation treatment, but the experimental group was provided with additional action observation. Independent t-tests were used to compare the differences between the groups, and repeated measured two-way ANOVA was used to compare the interaction between the groups. RESULTS: The result of the interactions between the groups and the periods showed significant increases in the weight distribution indexes (heel and toe; right and left), stability indexes, gait velocities and stride lengths (p<0.05). However, a comparison between the groups showed no significance in the weight distribution indexes (heel and toe), stability indexes, and stride lengths (p>0.05). CONCLUSION: Action observation plus functional electrical stimulation treatment should be considered as a therapeutic method for physical therapy for stroke patients to improve the weight distribution indexes, stability indexes, gait velocities, and stride lengths.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.7
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• pp.667-674
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• 2005

In this paper the gate overlap length of the LDMOST is optimized for obtaining longer device lifetime. The LDMOSI device with drift region is fabricated using the $0.25\;{\mu}m$ CMOS Process. The gate overlap lengths on drift region are $0.1\;{\mu}m,\;0.4\;{\mu}m\;0.8\;{\mu}m\;and\;1.1\;{\mu}m$, respectively. The breakdown voltages, on-resistances and hot-carrier degradations of the fabricated LDMOST devices are characterized. The LDMOST device with gate overlap length of $0.4\;{\mu}m$ showed the longest on-resistance lifetime, 0.02 years and breakdown voltage of 22 V and on-resistance of $23\;m\Omega{\cdot}mm^2$.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1925-1928
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• 1996

In this work, the behavior of conducting wire type particles existing inside the cylinder type coaxial electrode has been systematically investigated by charge simulation method and electrostatic force analysis from the view point of the acquired charging before being lifted off into the gap under the high ac voltage. Spheroidal charge are adopted as a image charge for the CSM analysis in order to calculate the acquired charges of the particles which are erected on the surface of the outer electrode. For this purpose, different material of the particle and their lengths and diameters have been considered in view to calculate their lift-off field, acquired charge and to understand their effect on the lift-off voltage. The results imply that the particle lengths and diameter have an different influence on the particle behavior in GIS system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.4
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• pp.451-456
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• 2013

Development of the technologies for offshore wind power is proceeding actively and the installation capacity is continuously increasing because of its many advantages in comparison with the land wind power. Accordingly, project for Southwestern 2.5GW offshore wind power plant is in progress in Korea. Design of electric power systems for offshore wind power plant is very important due to its high investment and operational costs. Hence, it needs to be designed in order to minimize costs. This way can be employed in determining the installation location of offshore substation for HVAC wind power plant. According to the offshore substation site, MV inter-array cable and HV export cable lengths vary and they change a total cost regarding submarine cable. This paper represents cost models with variables which are MV inter-array cable and HV export cable lengths to locate the offshore substation for HVAC wind power plant. It is classified into submarine cable installation cost, reactive power compensator installation cost, ohmic losses, and unsupplied energy cost. By minimizing a total cost, an appropriate installation site of the offshore substation is determined.