• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.1
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• pp.59-66
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• 2011

In this paper, a co-planar waveguide(CPW)-fed zeroth-order resonant(ZOR) antenna with an improved radiation efficiency was built and tested. The unit cell of the proposed antenna consists of a series metal-insulator-metal(MIM) capacitor and a shorted shunt stub inductor. In order to reduce the antenna size and to achieve the high radiation efficiency two shorted shunt stub arms bent by 90 degree were connected to the ground plane through the via. The proposed antenna consisting of two unit cells has an open ended composite right/left-handed(CRLH) transmission line structure. As a result the dominantly radiating parts of the antenna comes from shunt stub arms and vertical vias. The total size of the fabricated zeroth-order resonant antenna is $0.22\;{\lambda}_0{\times}0.22\;{\lambda}_0$. The measured gain and efficiency of the fabricated antenna have been enhanced by 3.07 dBi and 75 %, respectively, at the zeroth-order resonant frequency of 2.97 GHz.

• Journal of Acupuncture Research
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• v.31 no.4
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• pp.21-28
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• 2014

Objectives : Lumbar disc herniations are common conditions which induce severe pain and disability. We assessed the clinical effectiveness of Korean medical combination treatment. Methods : This is an observational study. We reviewed the medical records of 46 patients with lumbar disc herniations, who attended intensive Korean medical combination treatments at Mokhuri Neck and Back Hospital, Korea during March, 2012 to October, 2012. All the patients took combination treatments of acupuncture, Chuna and herbal medicines during the hospitalization treatments. Zero to ten pain numerating rating scale(NRS) of pain and SF-36 were assessed before and after treatments. Results : During the period, 46 patients with lumbar disc herniation participated in the treatments, respectively. Average admission duration were 20.32 days(SD 9.67) in lumbar disc patients. For lumbar patients, low back pain NRS decreased from $5.84{\pm}2.58$ to $2.12{\pm}1.74$(p<0.001) and radiating pain from $6.25{\pm}2.30$ to $2.59{\pm}1.97$(p<0.001). Total SF-36 score increased significantly after treatment in lumbar disc patients(p<0.001). Conclusions : Korean medical combination treatment might be effective in reducing pain and improving life quality of patients with lumbar disc herniation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.1
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• pp.25-31
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• 2011

In the underwater communications, transmitted acoustic signal is corrupted by interference from multipath. A parametric array transducer is capable of radiating a narrow beam with very low sidelobe levels. In certain cases, the parametric array transducer can help the multipath problem. To improve the performance of the underwater communications, the statistical signal processing methods will be required. In the paper, the communication system using a parametric array transducer was demonstrated. To detect the received signal of the communication system based on the on-off keying, the maximum likelihood method using averaged signal for a particular window size is used. The communication system has GUI using LebVIEW which allows the user to change the parameter. The GUI can also be easily modified based on the characteristics of a parametric array transducer. The implemented system can effectively evaluate the performance of the parametric array transducer.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.12 s.91
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• pp.1178-1183
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• 2004

In this paper, a novel microstrip patch antenna with switchable polarization is proposed. The proposed antenna has a simple structure, consisting of a square radiating patch, a pair of L-type spur-lines, and a microstrip line feed. It can produce either linear polarization or circular polarization by setting the diode on or off From the measured results, low cross polarization levels when operated in the linear polarization, and good axial ratios in the circular state have been observed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.985-995
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• 2003

In this paper, a study on optimization of three dimensional multi-layered metallic disk array structure(MDAS) excited by circular waveguides was performed to shape efficient flat-topped element patterns(FTEP) of ${\pm}$20$^{\circ}$ beam width. Each radiating element of the MDAS is composed of input, transition and radiation circular waveguides and finite metal disks stacked on radiation circular waveguide. It has an array structure of a hexagonal lattice appropriate for the conical beam scanning. The analytic algorithm for the MDAS was proposed and the code was also programmed using it. Optimal design parameters of the MDAS were determined through the optimal simulation process to obtain ${\pm}$20$^{\circ}$ FTEP. Also, bandwidth characteristics for FTEP and reflection coefficients of the MDAS were investigated and, as the results, it was shown that the MDAS could shape good FTEPs of ${\pm}$20$^{\circ}$ beam width in main planes at least within a 5.6 % frequency band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.4
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• pp.357-365
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• 2013

The 4 by 4 series slot sub-array antenna is proposed using substrate integrated waveguide(SIW) technology for 35 GHz of Ka band application. The proposed antenna is realized with multi-layered structure for compact size and easy integration features. 4 by 4 radiating slots are arrayed on top PCB with equal spacing and the feeding SIWs are arranged on middle and bottom PCBs for uniform power distribution. The multi-layered antenna is realized using RT/Duroid 5880 that has dielectric constant of 2.2 and the total antenna size is $750.76mm^2$. The individual parts such as radiators and feeding networks are simulated using full-wave simulator CST MWS. Furthermore, the total sub-array antenna also fabricated and measured the electrical performances such as impedance bandwidth under the criteria of -10 dB(490 MHz), maximum gain(18.02 dBi), sidelobe level(SLL)(-11.0 dB), and cross polarization discrimination (XPD)(-20.16 dB).

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.49.1-49.1
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• 2017

Comets are one of the most primordial solar system objects that hold the information of the early days of solar system formation inside their nuclei. Orbiting the Sun, they spew such ancient materials that have been buried for many years, creating dust and gas comae. Cometary dust grains absorb and scatter sunlight radiating the continuous light, while gas molecules form the line emissions. Eachof the comets has its own light patterns, which depends on the physical and chemical properties of the dust and gas components. In this regard, spectropolarimetrycan be a powerful tool to study the properties of cometary constituents free from contamination of each other. This methodology offers a series of information on the polarization degrees of the dust and gas components as well as on wavelength dependence of the polarization degree and polarization angle of cometary dust simultaneously. Herein, we will report the results of the spectropolarimetric study of comet 2P/Encke, which is one of the well-known objects for its shortest orbital period and its prominent aging signals. We performed a spectropolarimetric observation of comet 2P/Encke in its inbound orbit using the Higashi-Hiroshima Optical and Near-Infrared Camera (HONIR) at the Higashi-Hiroshima Observatory, Japan, on UT 2017 February 21 at high phase angle of =75.7 deg. Ourstudy of this interesting comet is the first and only one done through spectropolarimetry in a referred publication. We will discuss the most recent polarimetric results of our study in terms of 2P/Encke' scurrent evolutionary status.

• The Journal of Korean Physical Therapy
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• v.13 no.3
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• pp.509-527
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• 2001

The Sun's ray is composed of Infrared(49%), Visible light(40%) and Ultra violet(11%), however the ray getting to the earth is FIR(Far infrared; 60%), IR(Infrared; 20%), and UV(Ultra Violet; 20%). Human beings has utilized FIR already from time immemorial. Hershel found out Infrared for the first time. in the Industrial Revolution the Infrared and FIR had been begun to use making products. In these days, with contemporary science FIR would be begun to clear up the implication in the human body and organic compound. IR classified by wavelength three parts NlR, MIR, FIR. There is FIR which is radiated from healthy human body the wave length is 8-l4m. The human body is composed of proteins which get easily changed by a thermal factor (about 42 $^{\circ}$C over). FIR with low temperature can deeply penetrate on the human body composed things without troublesomes, since FIR has effectively operated on the human body at low temperature (35-40 $^{\circ}$C). When FlR penetrated on the human body. it would inhibit the abnormal genes and cells expression, and then information of DNA and RNA would be reexpressed for arranging DNA and RNA abnormal state. As FlR's receptors in the body, it could be presumed that N-glycosyl linkage of purine and deoxyribose, RNA splicing process, and Heat shock protein. To take the FIR which was a optimized wavewlength and strength, at first, we induced the characteristic algorithm and the computerized programing. Then we formed that the formular of optimized FIR with physical, mathematical logic and theory. especially, Plank, Kirchhoff, Wien, Stefan-Boltzmann's logic and law. In the long run, the formular was induced with integration mathematical, since we had to know the molecular wavelength. Based on the induced formular as above, we programmed the optimized FlR radiating computerized program. In this research, we designed the eletronic circuit f3r interfacing with human body to diagnosis and treatment with FIR sensor which radiated FIR wavelength optimized.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.43-55
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• 2013

In this paper, we propose a cylindrical active phased array antenna of Beam Steering Characteristics in the horizontal plane(H-plane) and vertical plane(E-Plane) on the cylinder form array structure. We design the bent dipole antenna of the cylindrical array structure adapted excellent mutual-coupling characteristics, designed and manufactured the cylindrical array antennas and power combiner/divider unit for power dividing and combining on the antenna. The radiating elements array spacing of Cylindrical array antenna were determined to avoid grating lobes at half power beam steering. Beam steering of the antenna was implemented with 6-bit phase shifter in the transceiver and have been designed based on the characteristics the antenna beam steering at -24 degrees to 24 degrees horizontal, vertical 0 degrees to 36 degrees beam steering. A cylindrical active phased array antenna that produced for verification the performance of the antenna are measured radiation characteristics in accordance with beam steering at L-Band.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.6
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• pp.68-73
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• 2009

One of the traditional optical methods to monitor a tool is a CCD sensor-based vision system which captures an aspect of the tool in real time. In the case using the CCD sensor, specific lens-modules are necessary to monitor the tool with higher resolution than its pixel size, and a microprocessor is required to attain desired data from captured images. Thus theses additional devices make the entire measurement system complex. Another method is to use a pair of an optical source and a detector per measuring axis. Since the method is based on the intensity modulation, the structure of the measurement system is simper than the CCD sensor-based vision system. However, in the case measuring the three dimensional position of the tool, it is difficult to apply to micro machine-tools because there may not be space to integrate three pairs of an optical source and a detector. In this paper, in order to develop a tool-origin measurement system which is employed in micro machine-tools, the improved method to measure a tool origin in x, y and z axes is introduced. The method is based on the intensity modulation and employs one pair of an optical source radiating divergent beams and a quadrant photodiode to detect a three dimensional position of the tool. This paper presents the measurement models of the proposed tool-origin sensor. The models were verified experimentally The verification results show that the proposed method is possible and the induced models are available for design.