• Journal of Korean Neurosurgical Society
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• v.39 no.4
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• pp.300-302
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• 2006

"Stunning" represents prolonged contractile depression of any muscular component after alleviation of severe ischemia, as shown in reperfusion following acute myocardial ischemia or ischemic stroke. Clinically, it presents with no or delayed recovery past to thrombolytic therapy but its pathogenic mechanism is not fully uncovered yet. We describe a unique case of a 63-year-old woman, who was undertaken endovascular coiling for the aneurysms, deteriorated several hours later without known cause, and showed delayed clinical improvement over the next 3 days following thrombolysis. Immediate post-thrombolysis magnetic resonance imaging scan showed no apparent abnormality except for high signal intensity within the corresponding hemisphere. Reversible but delayed nature of " brain stunning" can be explained by these images and it seems to be caused by a certain type of reperfusion injury.

• Investigative Magnetic Resonance Imaging
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• v.22 no.4
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• pp.272-276
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• 2018

Extra-articular tenosynovial giant cell tumor (TS-GCT) in retropharyngeal space is a rare case. We found only two case reports in the literature, in which one was located in retropharynx or prevertebral space of the cervical spine. We describe a rare case of TS-GCT in the retropharynx, which was initially misdiagnosed as oropharyngeal cancer. Furthermore, we want to assure that extraarticular diffuse type TS-GCT should be considered in the differential diagnosis of lesions showing low signal intensity in MRI scan.

• Journal of the Korea Society of Computer and Information
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• v.15 no.1
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• pp.13-21
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• 2010

IEEE 1149.1 test architecture was proposed to support the test of elements within the boards. It is a large serial shift register that uses the TDI pin as an input and the TDO pin as an output. Even though it performs the board level test perfectly, there is a problems of running system level test when the boards are equipped to the system. To test real time operation signal on test pin, output speed of serial shift register chain must be above double clock speed of shift register. In this paper, we designed a runtime test architecture and a runtime test procedure under running system environments to capture runtime signal at system clock rate. The suggested runtime test architecture are simulated by Altera Max+Plus 10.0. through the runtime test procedure. The simulation results show that operations of the suggested runtime test architecture are very accurate.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.2
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• pp.141-151
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• 2019

In this study, we propose a performance analysis of a quadrature-polarimetric(quad-pol) synthetic aperture radar(SAR) system for wide-swath operation mode and compare it with a single-pol system based on the operation mode. To achieve a shorter revisit time for an SAR satellite, we must observe a wide area, and two SAR operation modes exist for this purpose, which are called ScanSAR and SweepSAR. In general, a quad-pol SAR system can obtain a greater variety of information about a target than a single-pol system. Because this system affects system performance parameters, analyzing these effects is required. Based on a performance analysis of the wide-swath quad-pol SAR system, the system parameters and appropriate operation mode can be selected to satisfy the performance requirements.

• Journal of Yeungnam Medical Science
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• v.26 no.1
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• pp.30-37
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• 2009

Purpose : To radiologically differentiate renal oncocytoma from other renal solid tumors, we analyzed and characterized, retrogradely, radiologic findings of renal oncocytomas. Materials and Methods : Radiologic findings of pathologically proven renal oncocytoma were analyzed in 9 patients. CT was performed in all patients, ultrasonography in 4 patients and MRI in 3 patients.(51) Results : On ultrasonography, the echogenicity of the mass was slightly more hyperechoic than normal renal parenchyma in all 4 cases. Two cases were homogeneous and the remaining two cases were relatively homogeneous. On CT, all 8 cases showed iso-density to slightly low density compared to normal renal parenchyma and 5 cases were homogeneous but the central portion of the mass was of a slightly lower density than the peripheral portion in 3 cases. All six cases had an arterial phase scan and were heterogeneously enhanced. An irregular, lower-enhancing portion was found in the central portion of the mass. Segmental inversion of contrast enhancement was found in 5 of 6 cases that had a dynamic enhancement study. On MR T1-weighted imaging, the mass was of iso-signal intensity to normal renal parenchyma and the central portion of the mass had a slightly hypo-signal intensity than the peripheral portion. On T2-weighted imaging, 2 cases were heterogeneous; the peripheral portion was of low signal intensity and central portion was of higher signal intensity than normal renal parenchyma. One case was relatively homogeneous and showed a slightly lower signal intensity than that of normal parenchyma, except for a central small portion showing high signal intensity. For 2 cases that had a dynamic study, a segmental inversion of contrast enhancement was noted. Conclusion : Renal oncocytoma is seen as a well-marginated solid mass lesion. On enhanced scans it is heterogeneously enhanced and segmental inversion of contrast enhancement may be seen. The possibility of oncocytoma can be suggested in cases showing these radiologic findings.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.1
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• pp.51-57
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• 1999

This thesis is written about the Wired Logic Type Unit in developing equipment that the load is driven, that the interface unit connect with 1 Scan time to PO30 of operated PLC output contact with that a sensing signal of Temperature Sensor RSD Pt $100\Omega$ let generate the relay output of temperature controller and input the PLC. The PLC Test Kit in country that the PLC to be programmed at the PLC education place is able to drive the load, is done to do a education of PLC on status that interface process between PLC and load are disregarded. As Developing Kit for supplement this point, when the relay output of temperature controller to use Pt 100 of temperature sensor as mentioned on the former among every kinds of sensor feed back to the input of the PLC, as the equipment to act with real time system that the output contact of PLC operated to insert the WLTIJ among PC, PLC and the load, it can understand and see very easy the main principle of PLC use. The structure of WLTU to be a interface unit of load separated as to the point of contact and noncontact, sensor, indicating lamp and A contact and B contact that is belong to driving part, and a motor is belong to loading part.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.3
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• pp.299-311
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• 2011

In this paper, we have identified the system instability factors in a bistatic radar system using pulse chasing and considered their effects on the bistatic receiver's MTI(Moving Target Indication) improvement performance. The pulse chasing is a scan method that searchs a restricted area on the transmit pulse-to-pulse basis and the MTI filter is a signal processing that separates a target from some kinds of interferences such as clutter using small number of transmit pulses. Ideal MTI processing performance, e.g., clutter attenuation and improvement, has been limited by the property of the clutter itself, however, the MTI performance in a proposed bistatic receiver configuration could be affected by the receiving beam pointing error during pulse chasing scanning. Also, for the bistatic receiver, we have defined other system instability factors, which result from the time synchronization error, COHO's phase error, the frequency/phase synchronization error, and have analyzed their effects on the system performance improvement.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.113-113
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• 2001

Purpose： In the gradient echo EPI the conventional T2＊-weighted image is poor in signal as well distorted by the field inhomogeneity. By acquiring a proton density image in addition to th T2＊-weighted image at the same scan, the fMRI processing can be improved. Method： The central region of the k space is acquired twice at different time points after th RF pulse while acquiring the other regions onc as described in Fig. 1. In Fig. 1 the segment numbers are chronological. Then, we can get two images of different contrast by interleaving th central region in the k space as done in the dua contrast FSE.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.370-373
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• 2002

This paper proposes a new measurement system determine the localization and the type of object which use only three ultrasonic sensors, one the transmitter, one the receiver and one transduce doing both transmitter and receiver. this system can classifies the type and determines the pose of the target object. it used the method of Pseudoamplitude Scan. So it significantly simple the sensing system and reduce the signal processing time so that the working environment can be recognized in real time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.895-902
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• 2015

This paper presents a high-speed sensing and noise cancellation technique for large touch screens, which is called FDCS (Frequency Division Concurrent Sensing). Most conventional touch screen detection methods apply excitation pulses sequentially and analyze the sensing signals sequentially, and so are often unacceptably slow for large touch screens. The proposed technique applies sinusoidal signals of orthogonal frequencies simultaneously to all drive lines, and analyzes the signals from each sense line in frequency domain. Its parallel driving allows high speed detection even for a very large touch screens. It enhances the sensing SNR (Signal to Noise Ratio) by introducing a frequency domain noise filtering scheme. We also propose a pre-distortion equalizer, which compensates the drive signals using the inverse transfer function of touch screen panel to further enhance the sensing SNR. Experimental results with a 23" large touch screen show that the proposed technique enhances the frame scan rate by 273% and an SNR by 43dB compared with a conventional scheme.