• Korean Journal of Veterinary Research
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• v.46 no.1
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• pp.63-66
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• 2006

This case was found in Holstein cow suffering from dystocia. The twin calves in uterus were dead and removed by fetotomy. Gross anatomical analysis of thoracopagus siamese calf was carried out. Two normal heads were present on two necks, however, the twins were fused in the thoracic region. There were four forelimbs and an abnormal orientation of ribs. Two separate vertebral columns along the length of the animal ended with two tails. A single pericardium lay on the midline when opening the thorax. However, there were two almost completely hearts within the pericardial sac. Two heart were joined by a common cavernous venous sinuous. There were two sets of lungs. Each twins had a separate esophagus that entered a separated stomach. A large liver was fused and connected into two duodenums. The pelvis, large intestines and urinary tracts were separated. The twins are female and have a full complement of limb.

• The Journal of Korean Medicine
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• v.36 no.2
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• pp.43-49
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• 2015

Objectives: We evaluated the effect of the traditional Korean medical therapy of catgut-embedding therapy in patients with carpal tunnel syndrome (CTS). Methods: Thirteen patients(20 hands) with CTS underwent catgut-embedding therapy once per week for a total of 1-4 sessions. We measured the time to tingling in the fingers on performing Phalen's test. We also had patients use a visual analog scale (VAS) to indicate the severity of tingling. We also asked about the awakening time at night due to pain and tingling. We controlled the treatment as being limited to four sessions. Even if a patient had not been treated for four sessions, we ended the patient's treatment if symptoms resolved. Results: Patients who received catgut-embedding therapy showed significant improvements in the clinical symptoms of CTS. After treatment, in a total of 19 hands, the status of fourteen was changed from positive to negative in Phalen's test and the average of tingling occurrence time in that test was delayed. Among the 20 hands, the VAS in eight hands changed to zero and the average of VAS score decreased. Furthermore, in nine patients, four could sleep well without the use of a splint. Conclusions: Patients undergoing this traditional Korean medical therapy showed alleviation of finger tingling after even a single treatment. We thus concluded that this traditional Korean catgut-embedding therapy, may be effective for treating CTS. However, to confirm the effects of catgut-embedding therapy on CTS, further tests are required, including under the defined, strict conditions of a randomized controlled trial.

• Journal of IKEEE
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• v.24 no.1
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• pp.260-268
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• 2020

This paper presents the high frequency resonant inverter of class D SEPP(Single-Ended Push Pull) type using LS-ZVS-LSTC, which can reduce the switching losses during the turn-on and turn-off switching time. The analysis of high frequency resonant inverter using LS-ZVS-LSTC(Low-loss Turn-off Snubber Capacitor) proposed in this paper is described in general by adopting the normalized parameters. The operating characteristics of the proposed high frequency resonant inverter were also evaluated by using the control parameters such as the normalized control frequency(μ), the normalized load time constant(τ), the coupling factor(κ) and so on. Based on the characteristic values through the characteristics of evaluation, an example of the design method of the 1.8[kW] class D SEPP type high frequency inverter is suggested, and the validity of the theoretical analysis is verified using the experimental data.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.7
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• pp.1191-1198
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• 2001

MMIC low noise amplifiers for millimeter-wave application using 0.15 $\mu$m pHEMT have been presented in this paper. The design emphasis is on active device model and EM simulation. The deficiency of conventional device models is identified. A distributed device model has been adapted to circumvent the scaling problems and, thus, to predict small signal and noise parameters accurately. Two single-ended low noise amplifier are designed using distributed active device model for Q-band(40 ∼ 44 GHz) and V-band(58 ∼65 GHz) application. The Q-band amplifier achieved a average noise figure of 2.2 dB with 18.3 dB average gain. The V-band amplifier achieved a average noise figure of 2.9 dB with 14.7 dB average gain. The design technique and model employed provides good agreement between measured and predicted results. Compared with the published data, this work also represents state-of-the-art performance in terms of gain and noise figure.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.2
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• pp.113-119
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• 2017

In this paper, we have shown the performance analysis results of the LoRa low power wide area network under duty cycle local regulation in Korean RFID/USN frequency band. Especially, we analyzed uplink throughput and data transmission time of a single LoRa end device. From the analysis results, duty cycle regulation, in which a data transmission should be ended within 0.4 second, limits the performance of LoRa network. Therefore, it is necessary to revise Korea's duty cycle regulation referencing EU regulation in order to assess LoRa network in Korea.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.415-420
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• 2005

This paper presents the two lossless auxiliary inductors-assisted voltage source type half bridge (single ended push pull: SEPP) series resonant high frequency inverter for induction heated king roller in copy and printing machines. The simple high-frequency inverter treated here can completely achieve stable zero current soft switching (ZCS) commutation for wide its output power regulation ranges and load variations under its constant high frequency pulse density modulation (PDM) scheme. Its transient and steady state operating principle is originally described and discussed for a constant high-frequency PDM control strategy under a stable ZCS operation commutation, together with its output effective power regulation characteristics-based on the high frequency PDM strategy. The experimental operating performances of this voltage source SEPP ZCS-PDM series resonant high frequency inverter using IGBTs are illustrated as compared with computer simulation results and experimental ones. Its power losses analysis and actual efficiency are evaluated and discussed on the basis of simulation and experimental results. The feasible effectiveness of this high frequency inverter appliance implemented here is proved from the practical point of view.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.4
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• pp.380-387
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• 2005

We report the performance of an open-frame type low-voltage high-current DC-DC converter module developed using an active clamp forward converter circuit and single ended rectifier. The converter module is designed with the specifications of an 3.3V output voltage, 30A output current, 100W output power and 36-75V input voltage. The synchronous rectifier is used to reduce the conduction loss at high current level and constant current control using precision PCB resistance is adapted to enhance the over current protection function in the system configuration. A prototype converter module is successfully implemented within 8mm height and quarter brick size (58x37mm) and recorded an $95W/in^3$ power density, 90.6$\%$ efficiency and 0.07$\%$ voltage regulation for the entire Input voltage range, thereby demonstrating its application potentials to future telecommunication electronics.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.141-147
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• 2008

This paper describes the design of frequency down converting Mixer in the receiver to use compound semiconductor and CMOS product process. The basic theory and structure of frequency down converting Mixer is surveyed, and we design mixer circuit with active balun which use the compound semiconductor and CMOS process. This mixer convert a single ended signal to differential signal at input port of RF and LO instead of matching circuit to get dual band balanced mixer structure and characteristic broadband. This designed mixer has a conversion gain $-1{\sim}-6[dB]$ at $2{\sim}6[GHz]$ bandwidths. However, the simulation of the designed mixer with active balun has the result of a 7[dB] conversion gain for -2[dBm] LO input power and -10[dBm] input P1[dB] at 5.8[GHz].

• 사회경제평론
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• v.31 no.1
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• pp.25-61
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• 2018

Nowadays 87 regimes born in the same year with the Korean Association for Political Economy(KAPE in abbreviation) have ended historically. This paper surveys the research trends of KAPE after 2007 for the 30th founding anniversary. This survey is expected to help research way forward of KAPE. The main contents of the surveys are as follows. Global finance crisis caused by subprime mortgage crisis in 2007 expanded to global economic crisis resulting in the crisis of economics. KAPE criticized the mainstream economics with different approach and methodology as well as political economy copying with the crisis of economics and then focused on economics of inequality. However, the progressive economics is depressed under the conservative regime after 2007. As a result, the progressive economics have experienced the crisis of reproduction of knowledge and have become the peripheral science in Korea. With new regimes after 87 regimes, more important than restoration of the progressive economics is rebirth as the progressive economics corresponding to new regime and new era. This is responsibility of KAPE as the single association of the progressive economics in Korea.

• Journal of electromagnetic engineering and science
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• v.19 no.1
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• pp.64-70
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• 2019

In this study, a compact series-fed center-fed open-stub (SFCFOS) linear array antenna for K-band applications is presented. The antenna is composed of a single-line 10-element linear array. A symmetrical Chebyshev amplitude distribution (CAD) is used to obtain a low sidelobe characteristic against a uniform amplitude distribution (UAD). The amplitude is controlled by varying the width of the microstrip patch elements, and open-ended stubs are arranged next to the last antenna element to use the energy of the radiating signal more effectively. We insert a series-fed stub between two patches and obtain a low mutual coupling for a 4.28-mm center-to-center spacing ($0.7{\lambda}$ at 21 GHz). A prototype of the antenna is fabricated and tested. The overall size of the uniform linear array is $7.04{\times}1.05{\times}0.0563{\lambda}_g^3$ and that of the Chebyshev linear array is $9.92{\times}1.48{\times}0.0793{\lambda}_g^3$. The UAD array yields a ${\mid}S_{11}{\mid}$ < -10 dB bandwidth of 1.33% (20.912-21.192 GHz) and 1.45% (20.89-21.196 GHz) for the CAD. The uniform array design gives a -23 dB return loss, and the Chebyshev array achieves a -30.68 dB return loss at the center frequency with gains of 15.3 dBi and 17 dBi, respectively. The simulated and measured results are in good agreement.