• Journal of Yeungnam Medical Science
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• v.32 no.1
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• pp.42-46
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• 2015

Gouty ulcer can be caused by the accumulation of clumps of uric acid in body tissues that lead to acute or chronic inflammation at sites of accumulation. Furthermore, tophi-inhibiting granulation tissue may form a canal that channels microbial infection from the underlying involved joint space, and thus, presents the risk of osteomyelitis development. Accordingly, gouty ulcer must be treated appropriately. In this case, refractory wounds on gouty ulcers at the left shin and left radial ankle were treated by surgical debridement. Negative-pressure wound therapy was used successfully to prevent post-operative delayed wound healing.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1577-1579
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• 1994

200-MW pulse modulators(total 11units) for the PLS linac employ the SCR phase control circuit. It controls 3-phase AC line voltage for the high-voltage DC power supply (DCPS, maximum of 25kVDC, 4.2A) which charges the pulse forming network(PFN). The PFN delivers 400kV, 500A, ESW $7.5{\mu}s$ pulse power to the 80-MW klystron amplifier tube. The SCR regulates 3-phase AC power and feeds to the high voltage transformer. Two different types of the transformer configurations namely ${\Delta}-{\Delta}$ and ${\Delta}-Y$, are alternatively installed to 11 modulator units for the suppression of harmonic noises. RC filters and reactors are also installed. Currently, approximately 110-kW of average AC power per unit is consumed at the normal operation level of the modulator with 30pps. This paper presents the operational characteristics of the high power pulse modulator, especially the experimental results of the AC line harmonic components generated by the operation of the high power pulse modulator to suppress the switching noises from the SCR and rectifying diode arrays.

• JSTS:Journal of Semiconductor Technology and Science
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• v.9 no.1
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• pp.14-21
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• 2009

A digital differential transmitter based on CMOS inverter worked up to 2.8 Gbps at the supply voltage of 1 V with a $0.18{\mu}m$ CMOS process. By calibrating the output impedance of the transmitter, the impedance matching between the transmitter output and the transmission line is achieved. The PVT variations of pre-driver are compensated by the calibration of the rising-edge delay and falling-edge delay of the pre-driver outputs. The chip fabricated with a $0.18{\mu}m$ CMOS process, which uses the standard supply voltage of 1.8 V, gives the highest data rate of 4Gbps at the supply voltage of 1.2 V. The proposed calibration schemes improve the eye opening with the voltage margin by 200% and the timing margin by 30%, at 2.8 Gbps and 1 V.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1447-1448
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• 2007

고출력 펄스 전원으로 PFN Marx 펄스 전원공급장치를 설계 및 제작하였다. PFN Marx는 커패시터와 인덕터 그리고 스파크 갭과 전원을 공급하는 전원공급장치와 전류 인덕터로 구성하여 제작을 하였다. 여기에 사용하는 스파크 갭 스위치는 개스를 채우는 방식으로 개스의 압력을 조정하여 스위치의 스위칭 전압을 조정하여 준다. PFN Marx는 커패시터와 인덕터가 직병렬로 구성이 되며 펄스폭과 PFN의 임피던스를 결정하는 중요한 요소이다. PFN Marx 펄스 전원공급장치를 시뮬레이션 및 제작하여 시험을 하였다. 요구되는 사양은 전압 수십 kV, 펄스 폭수백 ns이다. 본 논문에서는 PFN Marx 펄스전원장치의 설계 및 시험에 대하여 고찰하고자 한다.

• Proceedings of the Korean Society of Potoscience Conference
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• 2005.06a
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• pp.42-42
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• 2005

• Korea Trade Review
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• v.47 no.6
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• pp.291-305
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• 2022

In this study, the volume of Pohang Port was predicted. All cargo of Pohang port, iron ore, steel, and bituminous coals were selected as prediction targets. SARIMA, Prophet, and Neural Prophet were used as analysis methods. The predictive power of each model was verified, and a predictive model with high performance was used to predict the volume of goods in Pohang port. As a result of the analysis, it was found that Neural Prophet showed the highest performance in all predictive power. As a result of predicting the future volume of goods until August 2027 using Neural Prophet, it was found that the volume of all items in Pohang port was decreasing. In particular, it was analyzed that the decline in steel cargo was steep. In order to increase the volume of cargo at Pohang port, it is necessary to diversify the cargo handled at Pohang port and check the policy of increasing the volume of cargo.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.298-298
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• 2006

There has been much interest in incorporating nanoscale voids into dielectric materials in order to reduce their k value, and thus in producing low-k porous interdielectric materials. One approach to the development of low-k dielectric materials is the templated polycondensation of organosilicate precursors in the presence of a thermally labile, organic polymeric porogen. The other is SiOCH films have low dielectric constant as well as good mechanical strength and high thermal stability through PECVD. In this article we explore the nanopore generation mechanism of organosilicate film using star-shape porogen and SiOCH film using bis-trimethylsilylmethane (BTMSM) precursor.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.547-547
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• 2013

This paper presents the understandings carried out for the installation of the hydrogen reservoir of the multi-gap pseudospark switch under developing for the accelerator applications. As a cold cold cathode switch, the pseudospark switch could replace the thyratron switch which has hot cathode and being used well currently in the high power field such as laser and accelerator applications. Especially in the klystron modulator, the key component is a switch which mostly defines the jitter and the instability of the modulator system. To get the less jitter and the instability, we need to find proper range of the pressure for the gas discharge inside gas switch. This could be achieved by the understanding of the characteristic of the nonevaporable getter (NEG) which is used as a hydrogen reservoir for the switch. Therefore we verified the characteristics of the NEG (St 172, Saes) and its installation in the switch. Finally we controlled the getter to find best pressure point for the pseudospark switch.

• JSTS:Journal of Semiconductor Technology and Science
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• v.9 no.4
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• pp.249-256
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• 2009

As a wireless handset deals with multiple application standards concurrently, RF transmitters and power amplifiers are required to be more power efficient and reconfigurable. In this paper, we review the recent advances in the design of the power amplifiers and transmitters. Then, the systematic design approaches to improve the performance with the digital baseband signal processing are introduced for the next generation mobile handset.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1764-1769
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• 1991

Recently, dexterous mechanical hands have become of interest in the field of robotics. In this paper, a new symbolic C-Y notation is proposed for the kinematic modeling, and we solve the kinematics of a simplified model of POSTECH Hand 1, which is a 5 fingered, 20 degrees of freedom anthropomorphic hand. POSTECH Hand I is designed to have distinctive kinematic structure and the kinematic analysis of the hand is carried out using C-Y notation. To prove the feasibility of C-Y notation, D-H notation is also applied to the POSTECH Hand 1. In the inverse kinematic analysis, we neglect the fingertip geometry and assume the point contact with 3 degrees of freedom constraints. The configurations which optimize manipulability index[2] was obtained based on the simulation experiments on the SUN-4 graphic workstation using SUNPhigs graphic software.