• Journal of the Optical Society of Korea
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• v.18 no.6
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• pp.766-771
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• 2014

Single-ring all-pass filters with various coupling ratios are designed, fabricated, and characterized to assess the validity of the split-step time-domain modeling approach, which is considered for direct simulation of time-domain characteristics, such as optical delay, of various ring resonator devices. When the coupling ratio of the single-ring all-pass filter is 0.4 and 0.8, the delay time is measured to be about 145 and 42 ps respectively, which is comparable to the time-domain modeling results of 151 and 47 ps respectively. The measurements for two- and three-ring all-pass filters are also found to agree quite well with the simulation results. With these results it is confirmed that the split-step time-domain model could be efficiently incorporated into an optical-communication simulation module for ring resonator delay components in an all-optical packet switching system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.21-28
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• 2006

In this paper, the proposed full-bridge high frequency isolated zoo voltage and zero current switching phase shifted pulse width modulation(ZVZCS PS-PWM)DC-DC converter among fuel cell generation system consist of 1.2[kW] fuel cell of Nexa Power Module, full-bridge DC-DC converter to boost the fuel cell low voltage($28{\sim}43[%]$) to 380[VDC] and a single phase full-bridge inverter is implemented to produce AC output(220[VAC], 60[Hz]). A tapped inductor filter with freewheeling diode is newly implemented in the output filter of the proposed full-bridge high frequency isolated ZVZCS PS-PWM DC-DC converter to suppress circulating current under the wide output voltage regulation range, thus to eliminate the switching and transformer turn-on/off over-short voltage or transient phenomena. Besides the efficiency of $93{\sim}97[%]$ is obtained over the wide output voltage regulation ranges and load variations.

• Journal of Industrial Technology
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• v.24 no.B
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• pp.47-57
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• 2004

This study is aiming to obtain the pabulum of architectural planning about out-patient clinic department in armed force hospital with search. The discussion was about characteristic problems and differentiated planning characteristics of common general hospital, So the conclusion of research is as follows. In army medical facilities, Because of architectural standard of out-patient clinic department about scale of facilities and characteristic in each examination-part is unprepared, it may have to be readied. Out-patient clinic department was become plan to scale about whole 7~8% in hospital to SB hospital in 95 but was planed about 5% of whole scale from PS hospital in 97. When plan hospital, increase of equipment and increase of module size about bed for the convenience of patient or employees are judged for cause in hospital since 97 years than previous hospital in 95.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.232-234
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• 2002

Due to development of power electronics technology, power conversion system are tend to small size, easy to use and light weight. Especially motor control system have increased concerns and interests about IPM(Intelligent Power Module) inverter, which contains protection circuit, drive circuit and power devices. So, we manufactured 3-phase inverter using DIP-IPM(Dual in-line package IPM) PS21245- E(1.5 Kw) made by MITSUBISHI Electric. Some of these features include -HVIC to Provide level shifting and gate drive for high-side IGBTs. The interface circuit between pwm controller and DIP-IPM can made by direct connection. In order to validate dynamic performance of the proposed system, the actual experiment worked out at wide speed range. The developed system is shown as a good dynamic characteristics.

• ETRI Journal
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• v.13 no.4
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• pp.52-57
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• 1991

We fabricated very high. speed PIN Photodiode module for the application of high speed optical receiver. OMVPE was used for the growth of InP layer on InGaAs absorption layer. The structure was the combination of mesa and planartype. Fabrication procedure was more complicated than simple mesa or simple planar type structure because we used semiinsulating InP substrate in order to reduce stray capacitance. The results at-5V were as follows : dark current was less than 1nA, capacitance was 0.55pF, and cutoff frequency was above 3GHz, and rise and fall time was about 100ps.

• Journal of Broadcast Engineering
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• v.7 no.4
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• pp.355-361
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• 2002

In this paper, several methods which guarantee the seamless editing when the splicing is applied to the MPEG-2 system streams are described. In the MPEG-2 system standard, it is recommended that the splicing technique is applied in the Transport Stream(TS) domain. However, in view of the video editing, the splicing at an arbitrary picture unit can not be guaranteed. The splicing in the PES domain is only considered in this paper because the PES is one of the MPEG-2 system streams and this result could be directly extended to the video splicing techniques in the TS or PS domain. Thus. the problems that might occur when different two PES streams are spliced and its effects to the video quality are compared and analyzed. Based on this analysis. several methods that can resolve these problems directly in the PES domain are proposed. Consequently, the computer simulation demonstrates that the splicing at a GOP modulo is guaranteed to have good video quality even without considering the state of the PES packet only if the PES_packet_length field of the PES packet header is used.

• ETRI Journal
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• v.26 no.6
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• pp.589-596
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• 2004

Packaging technologies for a broadband and narrowband modulator with a traveling wave electro-absorption modulator (TWEAM) device were developed. In developing a broadband modulator, the effects of the device and packaging designs on the broadband performance were investigated. The optimized designs were obtained through a simulation with the result that we developed a broadband modulator with a 3 dB bandwidth of 38 GHz in the electrical-to-optical (E/O) response, an electrical return loss of less than -10 dB at up to 26 GHz, an rms jitter of 1.832 ps, and an extinction ratio of 5.38 dB in a 40 Gbps non-return to zero (NRZ) eye diagram. For analog application, the effect of the RF termination scheme on the fractional bandwidth was studied. The microstrip line with a double stub as a matching circuit and a laser trimming process were used to obtain an $S_{11}$ of -34.58 dB at 40 GHz and 2.9 GHz bandwidth of less than -15 dB.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.3
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• pp.9-14
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• 2020

In this paper, Qualification Model of frequency synthesizer is designed for X-band SAR system and performed electrical and environment test. Designed frequency synthesizer generate 13.65 GHz with very low phase noise performance. The integrated phase noise from 10Hz to 1MHz is -37.91 dBc. IRF performances are analyzed according to phase noise and jitter. Also, thermal and structure analysis are achieved for stable operation in space environment. Designed frequency synthesizer is consist of 2 modules of 6U size and generate L-band, C-band, Ku-band. The result of this study would enhance the design ability of RF module and help the frequency synthesizer design for SAR payload system.

• Archives of Plastic Surgery
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• v.45 no.4
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• pp.367-374
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• 2018

Background This analysis presents patient-reported outcomes of breast augmentation procedures performed in Singapore using an inframammary fold incision and the "5 Ps" best practice principles for breast augmentation. These data are the first of their kind in Southeast Asian patients. Methods Through a retrospective chart review, patients who underwent primary breast augmentation with anatomical form-stable silicone gel breast implants using an inframammary fold incision were followed for ${\geq}6$ months postoperatively. The BREAST-Q Augmentation Module (scores standardized to 0 [worst] - 100 [best]) and Patient and Observer Scar Assessment Scale (POSAS; 1 [normal skin] to 10 [worst scar imaginable]) were administered. Responses were summarized using descriptive statistics. Patient-reported events were collected. Results Twenty-two Southeast Asian patients (mean age, 35.1 years) completed ${\geq}1$ postoperative BREAST-Q and POSAS assessment and were assessed 11 months to 5.5 years postoperatively. The mean postoperative BREAST-Q satisfaction with breasts and psychosocial well-being scores were 69.2 and 84.0, respectively. The mean POSAS score for their overall opinion of the scar was 4.2; the mean scores for all scar characteristics ranged from 1.2 to 4.2. Over 90% of patients (20/22) said that they would recommend the procedure. Patient complaints following surgery included anisomastia (possibly pre-existing; n=2), sensory loss at the nipple (n=2) or around the nipple (n=3), scarring (n=4), and slight capsular contracture (n=1). No patients required reoperation. Conclusions Southeast Asian patients reported high long-term satisfaction scores on the BREAST-Q scale and with their scar characteristics following breast augmentation using an inframammary fold incision, and nearly all said they would recommend this procedure. No reoperations were necessary in patients assessed for up to 5.5 years postoperatively.