• Journal of Digital Contents Society
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• v.18 no.1
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• pp.87-91
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• 2017

Recently, several kinds of researches using IoT wearable devices are active in the field of sports, design, emotional sciences and so on. The human bio data such as blood pulse, ECG, SKT signal, and GSR Signal producing from IoT wearable devices such as Watch, Smart-band, Grass can adapt to the meaningful future applications. Using the human's emotional data and a physical status with variation and so on, we can individually get the personal status. Due to knowing the personal emotion or physical status is related and connected to the valuable wallet of customers, the approach is more important in nowadays. Therefore, the personal information can effectively adapt to the marketing of the culture industry, which deals with emotions of customers. The research shows implementation steps for explaining overall architecture of the convergence research between Art and Technologies.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.215-220
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• 2005

In order to apply to land mine detection effectively, GPR using an optical electric field sensor as a receiver has been developed. The optical electric field sensor is very small and uses optical fiber instead of metallic coaxial cable. With the combination of these advantages and the bistatic radar system, it can be possible for an operator to measure quite flexible and safely. The sensor has been tested in stepped frequency radar system with frequency which consists of a vector network analyzer, a fixed double ridged horn antenna as transmitter. For considering effectiveness in real field, we applied impulse radar system, which consist of a digital oscilloscope and a impulse generator to produce the impulse. Detection of a PMN2 mine model was carried out by the impulse radar system at a sand pit. The PMN2 were detected clearly with sufficiently high resolution, the target contrast was almost the same while the scanning time decreased down to 1/100.

• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.397-404
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• 2011

In this paper, a research for the dynamic wheel loads of a 3D vehicle model, which relates to a tire-enveloping model, is carried out. A single truck with four axles is modeled as a 10-D.O.F. vehicle by modeling both contact length of tires and pitching of tandem spring axles. The dynamic equations of the vehicle are obtained using the Lagrange's equation, the solution of the equations is calculated by Newmark-${\beta}$ method. The validity of the developed 3D vehicle model is demonstrated by comparing results obtained from the proposed method with those from experimental data. The maximum impact factors of tire force are evaluated according to the various step bumps on which a 24-ton dump truck is running.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.43-46
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• 2018

This paper has designed a wideband bandpass filter (WBSF : Wide Band Stop Filter) using a stepped impedance resonator (SIR : Stepped Impedance Resonator) with improved performance and improved hairpin coupling structure. The SIR WBSF is small in size and has the advantage of having excellent bandstop characteristics. The designed BSF has a structure in which a quadrangular shaped hairpin of a / 4 length is arranged symmetrically on the upper and lower sides of the input and output transmission lines. The input and output terminals were terminated at 50 ohms for system applications. The center frequency of the SIR WBSF is 6.3 GHz, which is the second harmonic of 3.15 GHz. The designed filter has a 3dB bandwidth of 2.9 GHz and a transmission coefficient ($S_{21}$) of 33.2 dB. The reflection coefficient ($S_{11}$) at the center frequency is 0.106 dB. The application field is used for fixed microwave relay stations, fixed satellite and earth stations, and fixed satellite communications. The overall size is $20mm{\times}10mm$.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.6
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• pp.472-480
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• 2009

This paper describes the overmodulative SVPWM technique and harmonics analyses of three phase NPC type three-level inverter to the modulation index. Three phase NPC type three-level inverter adopted SVPWM to extend the linear region to 0.907, moreover, the following voltage compensation using Fourier series was adopted in the region of overmodulation to make it work to six-step level. PD type of multi carrier method is used with the double Fourier series for the analysis of output power harmonics characteristic. Simulation was performed by PSIM, and the harmonics characteristics of 3-level inverter in each region are analyzed. The side band harmonics of carrier frequency are dominant in the linear region, but these harmonic components are decreased as the inveter goes to overmodulation region, and the harmonics due to the fundamental frequency is increased gradually at the same time. The harmonic analyses are verified through the simulation and experimental results under the same condition.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.6
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• pp.514-521
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• 2009

This paper deals with a new overvoltage snubber for a diode-clamped 3-level IGBT inverter. Usually most power converters use snubber circuits to protect the switching devices from voltage spike. However, it is difficult for the diode-clamped multi-level converter to be protected from voltage spike with overvoltage snubber since the series connection of the switching devices. To solve the problem the characteristic of a overvoltage snubber for a DC-DC converter is analyzed, and a new snubber for a diode clamped 3-level inverter is proposed. The performance of the proposed snubber is verified through experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.10
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• pp.2236-2245
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• 1997

The DBS system is being highlighted as actual area for the information societics. Specially, the DBS have been proposed very useful system to access the broading service in more widely sea. But the antenna tracking system for maritime DBS receiving is requried complicated control system because of the those complex motion represented pitching, rolling and yowing etc. Our resesrch target is a development of tracking system to the KOREASEA(MUGUNGWHA-1,2) for the applicated small size shipping. So our development focus was concentrated the two development direction. The first focus was represented low-cost system for popularization of small-size shipping around sea of the Korea peninsula. The second focus was an adaptive possibilities with domestic eqdupiment which was developed satellite receiving for KOREASAT. The anntenna mount is designed a compact size and easy operation use to the Az/El 2-axis type which is operated by step motor. And this mount type is very useful on a ship in the near sea of Korea peninsula. Basic tracking method is used th step-tracking algorithm, and the ship's moving compensation is adapted to the closed loop control method by ship's moving detection of gyro sensor. Control part is consists of converter, countertime, VCO, micro-computer and it's software. Testing the operation by the ship's moving simulator, and algorithm is designed tracking and moving compensation by receiving state.

• Convergence Security Journal
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• v.8 no.1
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• pp.79-90
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• 2008

Services over SIP protocol are anticipated to be commonly used services in our usual life. Especially, presence is a new feature in SIP-based services and actually entities' presence information has close relationship with privacy of them. Also, the XCAP-based authorization is accepted as a highly probable method to protect privacy of entities in SIP-based services. However, there is no proposed presence service model except IM service and it's hard to find the reference model that shows a way how we can apply XCAP-based authorization method into presence service. In this paper, we proposed new presence service model which is applicable to the VoIP service. We suggested presence service model which is making use of XCAP-based authorization to get protection of privacy in a organized way and the suggested model's each messaging steps were reviewed using concrete examples. Contributions of this work is in the suggestion of privacy-aware presence service using XCAP-based authorization and its verification of its each messaging step.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.4
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• pp.380-386
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• 2014

In this paper, a higher-order mode coupler using coaxial-structure waveguide for Ku-band monopulse satellite tracking is proposed. The proposed higher-order mode coupler is built in a coaxial structure for compactness and weight reduction, making it suitable for mobile tracking systems. The inner circular waveguide of coaxial-structure is used to extract the fundamental mode signal and the high-order mode signal is extracted from the four slots of the outer circular waveguide and then transmitted via given stepped rectangular waveguide structure. The simulated results show that proposed higher-order mode coupler covers 250 MHz(12.75 GHz ~ 13.00 GHz) bandwidth with return loss and insertion loss characteristics. The antenna patterns of fundamental mode and higher-order mode applicable to monopulse tracking are generated successfully. Designed higher-order mode coupler using coaxial waveguide structure for Ku-band is expected to be used for high precision monopulse satellite tracking systems.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.1 s.307
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• pp.91-100
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• 2006

A scheme is proposed for implementing the block LMS algorithm in a block floating point framework that permits processing of data over a wide dynamic range at a processor complexity and coat as low as that of a fixed point processor. The proposed scheme adopts appropriate formats for representing the filter coefficients and the data. Using these and a new upper bound on the step size, update relations for the filter weight mantissas and exponent are developed, taking care so that neither overflow occurs, nor are quantifies which are already very small multiplied directly. It is further shown how the mantissas of the filter coefficients and also the filter output can be evaluated faster by suitably modifying the approach of the fast block LMS algorithm