• ETRI Journal
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• v.43 no.2
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• pp.232-245
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• 2021

As wireless communication continues to develop in limited frequency resource environments, it is becoming important to identify the state of spectrum utilization and predict the amount needed in future. It is essential to collect reliable information for data analysis. This paper introduces a platform that enables the gathering of the scheduling information of a long-term evolution (LTE) cellular system without connecting to the network. A typical LTE terminal can confirm its assigned resource information using the configuration parameters delivered from a network. However, our platform receives and captures only the LTE signal over the air and then enables the estimation of the data relevant to scheduling for all terminals within an LTE cell. After extracting the control channel signal without loss from all LTE subframes, it detects valid downlink control information using the proposed algorithm, which is based on the error vector magnitude of depatterned symbols. We verify the reliability of the developed platform by comparing it with real data from mobile phones and service operators. The average difference in resource block utilization is only 0.28%.

• Journal of IKEEE
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• v.23 no.2
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• pp.606-613
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• 2019

In this paper, a new method for flat sweeping automatic hold of wavelength swept laser has proposed. Through the performance test on the implemented laser, even 5 hours passed, the flat sweeping has held up well, and 56nm flat sweeping range, 1kHz sweeping frequency, and 8.8mW average optical power were obtained. This showes that the proposed can eliminate the necessity of hand-operated polarization control required for previous swept lasers in case of long time operation and also optical spectrum analyzer needed to monitor the sweeping spectrum status.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.90-95
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• 2023

We describe an optimal alignment method for improving accuracy of dynamic spectroscopic polarimeter based on monolithic polarizing interferometer. The dynamic spectroscopic polarimeter enables real-time measurements of spectral ellipsometric parameters by using a spectral carrier frequency concept. However, the non-polarizing beam splitter used in the monolithic polarizing interferometer cannot maintain the polarization state perfectly due to phase retardation caused by optical anisotropic characteristics of the non-polarizing beam splitter, resulting in degraded measurement accuracy. The effect of the beam splitter can be minimized through optimal alignment of the polarizers used in the polarizing interferometer and the analyzer. We demonstrate how much the proposed alignment method can enhance the measurement accuracy by comparing with previous alignment approach.

• Journal of Acupuncture Research
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• v.19 no.3
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• pp.95-106
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• 2002

The present study was designed to investigate the effects of various electroacupuncture(EA) stimulation on NADPH-diaphorase and Neuropeptide Y(NPY) in the cerebral cortex of Sprague-Dawley Rats. We evaluated the changes of NADPH-d-positive neurons using a histochemical method and the changes of NPY-positive neurons using a double labeling immunohistochemical method. The staining intensities of NADPH-d-positive neuron and NPY-positive neurons were assessed in a quantitative fashion using a microdensitometrical method based on optical density by means of an image analyzer. As to frequency, the optical density of NADPH-d-positive neurons of 2Hz-1 time EA group was significantly higher than that of 100Hz-1 time EA group in M1, Cg, and that of 100Hz-3 times EA group was significantly higher than that of 2Hz-3 times EA group in Vi, Au, Cg and Ins. As to treatment-time, the optical density of NADPH-d-positive neurons of 2Hz-1 time EA group was higher than 2Hz-3 times EA group in Vi, Au, Cg and Ins. And in Vi 100Hz-1 time EA group and in M1 100Hz-3 times EA group was more efficient. As to frequency, the optical density of NPY-positive neurons of 2Hz-1 time was significantly higher in Vi, and that of 100Hz-1 EA group was higher in M1. And that of 2Hz-3 times EA group was higher than 100Hz-3 times EA group in Cg. As to treatment-time, the optical density of NPY-positive neurons of 2Hz-1 time EA group was significantly higer than 2Hz-3 times EA in S1, Vi, Au. And that of 100Hz-1 time EA group was significantly higher than that of 100Hz-3 time EA in Cg. The present results demonstrated that EA changes the activity in NO and NPY system in the cerebral cortex of SHR and EA stimulation, like frequency and treatment-time, is of importance for this effect.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.5
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• pp.8-15
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• 2002

We optimally designed the VCO(voltage-controlled oscillator) with spiral inductor using the MOSIS HP 0.5${\mu}{\textrm}{m}$ CMOS process. With the developed SPICE model of spiral inductor, the quality factor of spiral inductor was maximized at the operating frequency by varying the layout parameters, e.g., metal width, number of turns, radius, space of the metal lines. For the operation frequency of 2㎓, the inductance of about 3nH, and the MOSIS HP 0.5 CMOS process with the metal thickness of 0.8${\mu}{\textrm}{m}$, oxide thickness of 3${\mu}{\textrm}{m}$, the optimal width of metal lines is about 20${\mu}{\textrm}{m}$ for the maximum Quality factor. With the optimized spiral inductor, the VCO with LC tuning tank was designed, fabricated and measured. The measurements were peformed on-wafer using the HP8593E spectrum analyzer. The oscillation frequency was about 1.610Hz, the frequency variation of 250MHz(15%) with control voltage of 0V - 2V, and the phase noise of -108.4㏈c(@600KHz) from output spectrum.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.8 s.111
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• pp.760-766
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• 2006

In this paper, we present a wideband patch antenna with folded and shorted structure for 5 GHz WLAN(Wireless Local Area Network). The proposed antenna used folded and shorted structure in the rectangular patch for miniaturization and wide frequency bandwidth. The antenna was designed by using 3D simulation program, HFSS(High Frequency Structure Simulator) software of the Ansoft company and the implemented antenna was measured by using HP 8720c network analyzer and far field measurement chamber. Simulation result on the return loss shows fairly good characteristic of at least 13.41dB in whole frequency range of interests, and the 10dB bandwidth is 1,523MHz which shows wide bandwidth characteristic. And the simulated maximum gain of the proposed antenna is 6.57 dBi at 5.825GHz. Measured result for the 10dB bandwidth of the implemented folded and shorted structure antenna is 1,377 MHz. Measured maximum gain of the implemented antenna is 6.87dBi at 5.775GHz. Measured results for the implemented antenna showed applicable performances for the 5 GHz WLAN.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.10
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• pp.687-698
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• 2001

This paper presents a three dimensional stacked pad area away (PAA) package configuration as an implementation method of radio frequency (RF) circuits. 224MHz RF circuits of intelligence traffic system(ITS) were constructed with the stacked PAA RF pakage configuration. In the process of manufacturing the stacked PAA RF pakage, RF circuits were partitioned to subareas following their function and operating frequency. Each area of circuits separated to each subunits. The operating characteristics of RF PAA package module and the electrical properties of each subunits were examined. The measurement of electrical parameters for solder balls which were interconnects for stacked PAA RF packages showed that the parasitic capacitance and inductance were 30fF and 120pH, respectively, which might be negligible in PAA RF packaging system. HP 4396B network/spectrum analyzer revealed that the amplification gain of a receiver and transmitter at 224 MHz was 22dB and 27dB, respectively. The gain was 3dB lower than designed values. The difference was probably generated from fabrication process of the circuits by employing commercial standard

• Journal of Acupuncture Research
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• v.25 no.4
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• pp.1-9
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• 2008

Objectives : This study was to investigate the effect of low frequency electroacupuncture according to acupoints combination on NOS positive neurons in the PAG and Hippocampus of Rat with adjuvant induced Rheumatoid arthritis. Methods : Arthritis was induced by intradermal injection of FCA into base of tail. Experimental group were divided into 6 group ; Normal, Control, $ST_{36}$, $SP_9$, $ST_{36}+SP_9$, and NA. Normal group was injected with normal saline and not treated electroacupuncture. Control group was injected with FCA and not treated electroacupuncture. ST36 group was injected with FCA and treated by 2 Hz electroacupuncture at $ST_{36}$. $SP_9$ group was injected with FCA and treated by 2 Hz electroacupuncture at $SP_9$. $ST_{36}+SP_9$ group was injected with FCA and treated by 2 Hz electroacupuncture at $ST_{36}+SP_9$. NA group was injected with FCA and treated by 2 Hz electroacupuncture at non acupoint. Each groups were evaluated by the number of NOS-positive neurons in PAG and hippocampus by using an image analyzer and a microscope. Results : 1. The number of NOS-positive neurons of the NA group were significantly decreased in the CA2-3. 2. The number of NOS-positive neurons of the ST36 group were significantly decreased in the PAG and CA2-3. 3. The number of NOS-positive neurons of the SP9 group were significantly decreased in the PAG and DG 4. The number of NOS-positive neurons of the ST36+SP9 group were significantly decreased in the PAG, CA1 and DG. Conclusions : It is expected that low frequency electroacupuncture can be used a treatment of rheumatoid arthritic pain and that treatment of electroacupuncture at combined acupoints is more efficient than treatment of low frequency electroacupuncture at one acupoint.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.485-493
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• 2007

Purpose: Heart rate variability(HRV) is the clinical consequence of various influences of the autonomic nervous system(ANS) on heart beat. HRV can estimate the potential physiologic rhythm from the interval between consecutive beats(RR interval or HRV data). It is known as RSA which represents respiration-related HR rhythmic oscillation. Previous studies demonstrated a specific breathing pattern(0.1Hz, 6breaths/min) to improve a physiological body condition related to the stress. In this paper, the level of stress would be evaluated in terms of three phases of the dental treatment, combined with 6breaths/min. Methods: These phases include before, during and after tooth extraction or anesthesia or something.36 patients' stresses were assessed using HRV stress analyzer in each phase in Kangdong Sacred Heart Hospital, and Chuncheon Sacred Heart Hospital, Hallym University Medical Center from Jun. to Sept. of 2007. HRV 5-min data collected were analyzed in time-domain and frequency-domain to evaluate the activity of autonomic nervous system(ANS) which represents the level of stress. Results: All HRV parameters including HF(high frequency), LF(low frequency) and LF/HF ratio showned a significant change affecting the ANS balance. There was a 6.4% difference between R(LF/HF)s on general breathing pattern for balance of Autonomic nervous system, but on controlled breathing pattern, 0.1Hz, was made narrow till 1.4%. The activity of ANS has increased by 1.4% on general breathing pattern, and by 2.9% on controlled breathing pattern, 0.1Hz. Conclusion: After analysis of preoperative stress changes and effect of breathing pattern of 0.1 Hz on the stress in 36 patients who have undergone third molar extraction, following was concluded. In the preoperative stage, the sympathetic change was the greatest?after the?anesthetic injection, and stress was relieved by controlling the breathing pattern to a frequency of 0.1Hz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.8
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• pp.808-820
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• 2014

In this paper, we fabricated two on-wafer type DUT(Device-Under-Test)s; a 10-dB attenuator and an amplifier using commercially available MMIC and we proposed the measurement method of the noise parameters for the two fabricated DUTs. Since the 10-dB attenuator DUT is a passive device, its noise parameters can be accurately determined when its S-parameters are measured. In the case of the amplifier DUT, its noise parameters are available in the datasheet. Hence, the measured noise parameters using the proposed method can be assessed by comparing with the known noise parameters. The noise parameter measurement method having been presented by the authors requires the S-parameters of the 8-port network used in the measurement and limited to coaxial type DUTs. When on-wafer probes are included in the 8-port network, the 8-port S-parameters requires the measurements with different kinds of connectors. In this paper, we obtained the 8-port S-parameters using the Smart-Cal function in the network analyzer. The measured noise parameters shows about ${\pm}0.2dB$ fluctuations for $NF_{min}$. Other noise parameters with the frequency change show good agreement with the expected results.