• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.2
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• pp.55-64
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• 2017

Purpose Recently, with the spread of SPECT/CT, various image correction methods can be applied quickly and accurately, which enabled us to expect quantitative accuracy as well as image quality improvement. Among them, the Collimator Detector Response(CDR) recovery is a correction method aiming at resolution recovery by compensating the blurring effect generated from the distance between the detector and the object. The purpose of this study is to find out quantitative change depending on the change in detection distance in SPECT/CT images with CDR recovery applied. Materials and Methods In order to find out the error of acquisition count depending on the change of detection distance, we set the detection distance according to the obit type as X, Y axis radius 30cm for circular, X, Y axis radius 21cm, 10cm for non-circular and non-circular auto(=auto body contouring, ABC_spacing limit 1cm) and applied reconstruction methods by dividing them into Astonish(3D-OSEM with CDR recovery) and OSEM(w/o CDR recovery) to find out the difference in activity recovery depending on the use of CDR recovery. At this time, attenuation correction, scatter correction, and decay correction were applied to all images. For the quantitative evaluation, calibration scan(cylindrical phantom, $^{99m}TcO_4$ 123.3 MBq, water 9293 ml) was obtained for the purpose of calculating the calibration factor(CF). For the phantom scan, a 50 cc syringe was filled with 31 ml of water and a phantom image was obtained by setting $^{99m}TcO_4$ 123.3 MBq. We set the VOI(volume of interest) in the entire volume of the syringe in the phantom image to measure total counts for each condition and obtained the error of the measured value against true value set by setting CF to check the quantitative accuracy according to the correction. Results The calculated CF was 154.28 (Bq/ml/cps/ml) and the measured values against true values in each conditional image were analyzed to be circular 87.5%, non-circular 90.1%, ABC 91.3% and circular 93.6%, non-circular 93.6%, ABC 93.9% in OSEM and Astonish, respectively. The closer the detection distance, the higher the accuracy of OSEM, and Astonish showed almost similar values regardless of distance. The error was the largest in the OSEM circular(-13.5%) and the smallest in the Astonish ABC(-6.1%). Conclusion SPECT/CT images showed that when the distance compensation is made through the application of CDR recovery, the detection distance shows almost the same quantitative accuracy as the proximity detection even under the distant condition, and accurate correction is possible without being affected by the change in detection distance.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.87-95
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• 2014

This paper describes a dual channel receiver design for CIS interfaces. Each channel includes CTLE(Continuous Time Linear Equalizer), sampler, deserializer and clocking circuit. The clocking circuit is composed of PLL, PI and CDR. Fast lock acquisition time, short latency and better jitter tolerance are achieved by adding OSPD(Over Sampling Phase Detector) and FSM(Finite State Machine) to PI-based CDR. The CTLE removes ISI caused by channel with -6 dB attenuation and the lock acquisition time of the CDR is below 1 baud period in frequency offset under 8000ppm. The voltage margin is 368 mV and the timing margin is 0.93 UI in eye diagram using 65 nm CMOS technology.

• Child Health Nursing Research
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• v.13 no.2
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• pp.222-229
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• 2007

Purpose: This study was done to evaluate the validity of the Korean - Child Development Review in screening children with developmental risks. Method: The participants in the study were 172 children aged 6-75 months old and their parents. Data were collected by questionnaire or interview. Korean Denver II and Bayley test were administered with K-CDR for validation of children who were referred for developmental assessment at D University Hospital or public health center. The data were analyzed using correlation, $X^2$ test, and cross tab analysis. Results: There was a significant relationship between the K-CDR and Korean Denver II. The correlation coefficients were .42 to .61 by developmental sector. The sensitivity and specificity of K- CDR were .84 and .66 respectively when "abnormal" with MDI of Bayley test defined as lower than 85 the score which was used as a diagnosis of developmental delay. The responses to 6 questions for parents showed significant differences according to 3 groups by developmental state. Parents of children in the developmental disability group more frequently checked problems from the 26 problem checklist about their children's development and behavior. Conclusion: The results show that K-CDR is valid and has good sensitivity and moderate specificity in screening developmental delay.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.3
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• pp.404-416
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• 2015

Small-area, low-power coarse and fine frequency detectors (FDs) are proposed for an adaptive bandwidth referenceless CDR with a wide range of input data rate. The coarse FD implemented with two flip-flops eliminates harmonic locking as long as the initial frequency of the CDR is lower than the target frequency. The fine FD samples the incoming input data by using half-rate four phase clocks, while the conventional rotational FD samples the full-rate clock signal by the incoming input data. The fine FD uses only a half number of flip-flops compared to the rotational FD by sharing the sampling and retiming circuitry with PLL. The proposed CDR chip in a 65-nm CMOS process satisfies the jitter tolerance specifications of both USB 3.0 and USB 3.1. The proposed CDR works in the range of input data rate; 2 Gb/s ~ 8 Gb/s at 1.2 V, 4 Gb/s ~ 11 Gb/s at 1.5 V. It consumes 26 mW at 5 Gb/s and 1.2 V, and 41 mW at 10 Gb/s and 1.5 V. The measured phase noise was -97.76 dBc/Hz at the 1 MHz frequency offset from the center frequency of 2.5 GHz. The measured rms jitter was 5.0 ps at 5 Gb/s and 4.5 ps at 10 Gb/s.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.65-85
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• 1999

Objectives: To determine the effect of interpolation functions when processing the digital periapical images. Material and Methods: The digital images were obtained by Digora and CDR system on the dry skull and human subject. 3 oral radiologists evaluated the 3 portions of each processed image using 7 interpolation methods, and ROC curves were obtained by trapezoidal methods. Results: The heighest Az value(0.96) was obtained with cubic spline method and the lowest Az value(0.03) was obtained with facet model method in Digora system. The heighest Az value (0.79) was obtained with gray segment expansion method and the lowest Az value(0.07) was obtained with facet model method in CDR system. There was significant difference of Az value in original image between Digora and CDR system at a=0.05 level. There were significant differences of Az values between Digora and CDR images with cubic spline method, facet model method, linear interpolation method and non-linear interpolation method at α=0.1 level.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.9
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• pp.7-13
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• 2009

This paper presents a multi-channel transceiver that achieves a data rate of 3.125Gb/s/ch. The LVDS is used because of its noise immunity and low power consumption. And a pre-emphasis circuit is also proposed to increase the transmitter speed. On the receiver side, a low-power CDR(clock and data recovery) using 1/4-rate clock based on dual-interpolator is proposed. The CDR generates needed additional clocks in each recovery part internally using only inverters. Therefore each part can be supplied with the same number of 1/4-rate clocks from a clock generator as in 1/2-rate clock method. Thus, the reduction of a clock frequency relaxes the speed limitation and lowers power dissipation. The prototype chip is comprised of two channels and was fabricated in a $0.18{\mu}m$ standard CMOS process. The output jitter of transmitter is loops, peak-to-peak(0.31UI) and the measured recovered clock jitter is 47.33ps, peak-to-peak which is equivalent to 3.7% of a clock period. The area of the chip is $3.5mm^2$ and the power consumption is about 119mW/ch.

• Journal of information and communication convergence engineering
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• v.9 no.3
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• pp.305-309
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• 2011

This paper proposes a new rotational frequency detector (RFD) for phase-locked loop (PLL) or clock and data recovery (CDR) applications for fast frequency acquisition. The proposed RFD uses the four states finite state machine (FSM) model to accelerate the frequency acquisition time. It is modeled and simulated with MATLAB Simulink. The functionalities of the proposed RFD are examined and the results are compared to those of a conventional RFD. The proposed RFD's frequency acquisition time is four times faster than that of a conventional one. The proposed RFD incorporated with a phase detector (PD) in PLL or CDR is expected to improve the frequency and phase acquisition performance later greatly.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.3
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• pp.287-292
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• 2016

A multiphase clock and data recovery (CDR) circuit having a novel rotational bang-bang phase detector (RBBPD) is demonstrated. The proposed 1/4-rate RBBPD decides the locking point using a single clock phase among sequentially rotating 4 clock phases. With this, our RBBPD has significantly reduced power consumption and chip area. A prototype 10-Gb/s 1/4-rate CDR with RBBPD is successfully realized in 65-nm CMOS technology. The CDR consumes 5.5 mW from 1-V supply and the clock signal recovered from $2^{31}-1$ PRBS input data has 0.011-UI rms jitter.

• Journal of Power Electronics
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• v.16 no.3
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• pp.894-904
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• 2016

This study examines the zero-voltage switching (ZVS) operation of an active-clamped forward converter (ACFC) with a current-doubler rectifier (CDR). The ZVS condition can be obtained with a much smaller leakage inductance compared to that of a conventional ACFC. Due to the significantly reduced leakage inductance, the design is optimized and the circulating loss is reduced. The operation of the ACFC with a CDR is analyzed, and a detailed ZVS analysis is conducted on the basis of a steady-state analysis. From the results, a design consideration for ZVS improvement is presented. Loss analyses of the converters shows that enhanced soft-switching contributes to an efficiency improvement under light-load condition. Experimental results from a 100-W (5-V/20-A) prototype verify that the ACFC with a CDR can attain ZVS across an extended load range of loads and achieve a higher efficiency than conventional ACFCs.

• Journal of Oriental Neuropsychiatry
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• v.23 no.3
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• pp.99-116
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• 2012

Objectives : The purpose of this study is to evaluate the effects of Needle-Embedding Therapy on dementia patients. Methods : We recruited 3 dementia patients who have been experiencing memory disorder and orientation disorder. The patients had been evaluated with Mini-Mental State Examination-K (MMSE-K), Global Deterioration Scale (GDS) and Clinical Dementia Rating (CDR). The patients were treated with herbal medication (Sunghyangjunggi-san) and acupuncture. After 15 days, the patients were added to Needle-Embedding Therapy. We measured MMSE-K, GDS and CDR for every 15 days. The effects of additional Needle-Embedding Therapy were compared with the effects of acupuncture and herbal medicine. Results : After Needle-Embedding Therapy was added, Patients' memory and orientation have been improved and the score of MMSE-K ascended. The grade of GDS and CDR were maintained or decreased. Conclusions : This study suggests that Needle-Embedding Therapy is significantly effective on Dementia patients.