• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.806-812
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• 2009

In this paper, the omnidirectional circularly polarized(CP) antenna using arc-shaped mushroom structure with curved branch is proposed. To obtain a vertical polarization and an omnidirectional radiation pattern, the CP antenna uses zeroth-order resonance(ZOR) mode of composite right and left handed(CRLH) transmission line. The horizontal polarization is achieved by the curved branches. Also, the spacing between curved branch and arc-shaped mushroom structure gives the $90^{\circ}$ phase difference between vortical and horizontal polarization. The proposed antenna, therefore, has an omnidirectional CP radiation pattern In the azimuthal plane. The electrical size of the proposed antenna is reduced by 38%, compared with that of the previously presented omnidirectional CP antenna. In addition, the CP antenna is simply designed without $90^{\circ}$ phase shifter and dual feed line. The proposed antenna uses a Bazooka balun for good impedance matching and radiation pattern. To improve 3 dB axial ratio in XY plane, the designed antenna is optimized. After optimization, the measured 3 dB axial ratio in XY plane is observed in $86{\sim}282^{\circ}$.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.3
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• pp.133-140
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• 2012

In this study, 3 kinds of models about bike frame are simulated with static structural analysis, And fatigue life, damage and durability according to fatigue load are analyzed. A bike frame model with diamond type is compared with another model on the reinforced support with its type. In case of the reinforced support type, maximum equivalent stress or total deformation is shown with 10% or 20% more than the diamond type respectively. At both types of models, the trends of fatigue life and damage at both types are same. 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable among the cases of nonuniform fatigue loads. In case of 'Sample history' with the average stress of 0 to -1MPa and the amplitude stress of 0 to 1MPa, the possibility of maximum damage becomes 3%. This stress state can be shown with 6 times more than the damage possibility of 'SAE Bracket history' or 'SAE transmission'. In case of the reinforced support type, fatigue life becomes shorter and damage probability becomes larger at the right side installed with support than diamond type. The structural result of this study can be effectively utilized with the design on bike frame by investigating prevention and durability against its damage.

• School Mathematics
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• v.15 no.2
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• pp.243-262
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• 2013

This study attempts to create an analytical framework of the transformation and transmission of knowledge by teachers to students. I focuses on the assertion that the cognitive thinking of a teacher is reflected in his use of mathematical language. Mathematical language is one of the critical elements of communicating mathematical knowledge to students. I examined the cognitive teaching style of different teachers as expressed in their use of mathematical language. An analytical framework of Mathematics Teaching styles was created integrating thinking factors of each visual and analytic style into 5 categories. After that, I regarding the teaching style of mathmatics teachers places its significance not on which teaching style is right or wrong but on identifying the strong and weak points of the teaching styles through actual analysis. With the help of this analytical framework, I conducted an analysis on the videotaped classes and found that the teachers were not biased to one side but in fact there were teachers who demonstrated visual, analytic or mixed teaching style. Therefore, I concludes that math teachers can analyze their teaching styles and improve them through the analytical framework provided in these findings.

• Journal of Satellite, Information and Communications
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• v.9 no.1
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• pp.6-12
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• 2014

The traditional broadcasting service has advanced into a smart media service with the help of communication network. in In the smart media ecosystem, a variety of innovative media services have been provided by new players. However, terrestrial broadcasting service companies seem to lag comparatively behind new players in spite of their powerful contents production capacity and stable terrestrial media delivery networks. In this paper, we design a proposed media platform based on a set-to-box (STB) with various new function for terrestrial ultra-high definition(UHD) broadcasting service. Also we suggest specific transmission network architecture and platform components for UHD broadcasting service. The proposed media platform is expected to increase the number of direct home reception and to enhance the right of the free-viewers which is one of the natural mission of terrestrial broadcasting company. Also it can provide some profit model of UHD terrestrial broadcasting service with new value-added services.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.1
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• pp.23-27
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• 2005

The present study was performed to investigate the effects of intra-articular injection of interleukin-1${\beta}$ (IL-1${\beta}$) on the formalin-induced temporomandibular joint (TMJ) pain. Under anesthesia, a 30-gauge needle was introduced into the right TMJ region for injection of formalin. Microinjection of 50 ${\mu}l$ of 5% formalin significantly produced noxious scratching behavioral response, and the scratching behavior lasted for 40 min. Although the responses produced by formalin injection were divided into two phases, the response of 1st phase did not significantly differ from the scratching behavior response in the saline-treated group. We examined the effects of intra-articular injection of IL-1${\beta}$ on the number of noxious behavioral responses produced by 50${\mu}l$ of 5% formalin injection. Intra-articular injection of 100 pg and 1 ng of IL-1${\beta}$ significantly increased the number of behavioral responses of the 2nd phase, while 10 pg of IL-1${\beta}$ did not change the formalin-induced behavioral responses. To investigate whether IL-1 receptor was involved in the intra-articular administration of IL-1${\beta}$-induced hyperalgesic response, IL-1 receptor antagonist (IL- ra, 50 ng) was administrated together with IL-1${\beta}$ injection. IL-1${\beta}$ receptor antagonist blocked IL-1${\beta}$- induced hyperalgesic response in the TMJ formalin test. These results suggest that intra-articular injection of IL-1${\beta}$ facilitated the transmission of nociceptive information in the TMJ area.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8C
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• pp.637-644
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• 2012

In this paper, a new compact power divider is suggested. Instead of the quarter wavelength transmission line(TX-line)s for the branches of the conventional Wilkinson's power divider design method, we use our composite right- and left-handed(CRLH) TX-line zeroth order resonator(ZOR) bandpass filters of one twelfth wavelength and reduce the physical length of the power divider. Besides, the filters in the branches can secure the passband for power-division. To validate the proposed power divider, we take an L-band for millitary satellaite transponder as the test case and the performances of the circuit and full-wave simulation results with the CRLH properties of the structure are shown with the dispersion curve and E-field at the ZOR. The measurement is compared with the simulation results. Also, the size reduction effect by the proposed scheme is addressed

• Smart Structures and Systems
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• v.18 no.4
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• pp.643-662
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• 2016

The monitoring of structural integrity of pipeline tapered thread connections is of great significance in terms of safe operation in the industry. In order to detect effectively the loosening degree of tapered thread connection, an active sensing method using piezoceramic transducers was developed based on time reversal technique in this paper. As the piezoeramic transducers can be either as actuators or sensors to generate or detect stress waves, the energy transmission for tapered thread connection was analyzed. Subsequently, the detection principle for tapered thread connection based on time reversal was introduced. Finally, the inherent relationship between the contact area and tightness degree of tapered thread connection for the pipe structural model was investigated. Seven different contact area scenarios were tested. Each scenario was created by loosening connectors ranging from 3 turns to 4.5 turns in the right tapered threads when the contact area in the left tapered threads were 4.5 turns. The experiments were separately conducted with a highly noisy environment and various excitation signal amplitudes. The results show the focused peaks based on time reversal have the monotonously rising trend with the increase of the contact areas of tapered threads within an acceptable monitoring resolution for metal pipes. Compared with the energy method, the proposed time reversal based method to monitor tapered threads loosening demonstrates to be more robust in rejecting noise in Structural Health Monitoring (SHM) applications.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.5
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• pp.475-480
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• 2012

This study on the methode is easied to distinguish with emotional visual lighting on AtoN facility using 3colors LED, and which is controlled to on-off switching of approach light in shore or harbor. The identification have easied to provide a differentiation between the AtoN facility of red and white light and surrounding light in harbor both sides. And the integrated controller have designed to left-right and serial sequential lighting system for harbor guidance using the GPS synchronous or timer. There is expectation effect that is prevent a confusion about distinguish of facility by ship's operator and to beautify a night scene of harbor, which is expressed to emotional identification lighting and variable color lighting on AtoN body by vertical layer color lighting using LED. In addition, the performance of AtoN is implemented to display with guidance light the harbor safety message by morse code lighting. Effectiveness of system is enhanced that age and power consumption reduce by candle alternated high light LED.

• Journal of Arbitration Studies
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• v.21 no.2
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• pp.47-64
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• 2011

The China International Economic and Trade Arbitration Commission(CIETAC) released online arbitration rules which apply the resolution of disputes over electronic commerce transactions, as well as other economic and trade disputes in which the parties agree to do. The evidence submitted by the parties may be electronic evidence created, sent, received or stored by electronic, optical or magnetic means. Electronic evidence with a reliable electronic signature shall carry the same effect and probative force as a document with a hand-written signature. Where a case is tried in a tribunal, the arbitration tribunal shall conduct an online trial hearing using internet video conference or other electronic or computer communication means. Unless the parties have another agreement, summary procedure shall apply to cases where the amount in dispute exceeds RMB 100,000 but no more than RMB 1 million, or where the amount in dispute exceeds RMB 1 million and a party submits a written application for summary procedure after obtaining the written consent of the other party. Unless the parties have agreed otherwise, fast-track procedure shall apply to cases where the amount in dispute does not exceed RMB 100,000 or where the amount in dispute exceeds RMB 100,000 and a party submits a written application for fast-track procedure after obtaining the written consent of the other party. Notable features of the Online Rules are as follows; first, there is not detailed consideration for online arbitration. Second, communications between the parties and the tribunal are allowed only through the Secretariat. Third, elaborate provisions regarding the electronic submission and transmission of documents is provided for. Forth, various factors must be considered by the tribunal in deciding the evidence's reliability. Fifth, reasonable endeavours is levied on CIETAC to keep data communications secure and encrypted. Sixth, the tribunal has the right to investigate and collect relevant evidence. And finally different procedures are provided for in consideration of the various types of E-commerce.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.12
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• pp.1712-1718
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• 2013

This paper proposes a compact dual-band 3-way power divider that helps lowering the weight of a transceiver for the L-band or multi-purpose satellite communication. Instead of the multi stages or tapering which ends up with loss accumulation and size-growth, the non-linear dispersive phases from the metamaterial CRLH(composite right and left-handed) properties are obtained by the accurate formulation and implemented by the short transmission line segments. Firstly, the CRLH dual-band two-way unequal power divider and equal power divider are separately designed. And then, the input of the two-way equal power divider is plugged in the output port of the unequal one, and the entire geometry is slightly adjusted for the desirable performance. The circuit analysis and full-wave simulation are used to predict the frequency responses and validated by the measurement of the prototype. Besides, the size-reduction effect is addressed.