• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.2
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• pp.29-36
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• 2000

The principle and design of two-stage CMOS operational amplifier with rail-to-rail input and class-AB output stage is presented. The rail-to-rail input stage shows almost constant transconductance independent of the common mode input voltage range in global transistor operation region. This new technique does not make use of accurate current-voltage relationship of MOS transistors. Hence it was achieved by using simple linear relationship of currents. The simulated transconductance variation using SPICE is less the 4.3%. The proposed global two-stage opamp can operate both in strong inversion and in weak inversion. Class AB output stage proposed also has a full output voltage swing and a well-defined quiescent current that does not depend on power supply voltage. Since feedback class- AB control is used, it is expected that this output stage can be operating in extremely low voltage. The variation of DC-gain and unity-gain frequency is each 4.2% and 12%, respectively.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.2
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• pp.235-250
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• 1990

Thirty-nine patients (forty-four joints) who had been diagnosed as having meniscus perforation of the temporomandibular joint by inferior joint space arthrography and had been treated by surgical procedures were evaluated retrospectively. Information of clinical findings, arthrotomographic findings and surgical findings was collected on a standardized form and evaluated. The results were as follows: 1. On the 34 patients of 38 joints which were surgically confirmed perforation of meniscus or its attachments of the temporomandibular joint, there were 29 females and 5 males (5.8:1). The average age was 36 years (range 17 to 70). 2. The common clinical findings of group that had meniscus displacement without reduction and with perforation were pain on the affected joint and limitation of mouth opening. In the group showing meniscus displacement with reduction and with perforation the common clinical findings were pain and clicking on the affected joint. 3. 32 joints (84.2%) were arthrotomographically anterior meniscus displacement without reduction and with perforation, 6 joints (15.8%) showed anterior meniscus displacement with reduction and with perforation. 4. Joints categorized arthrotomographically as having meniscus displacement without reduction and with perforation were less likely to have full translation of the condyle in comparison with the normal or meniscus displacement with reduction and with perforation groups. (p<0.05) 5.The arthrographic findings of 44 joints having meniscus perforation were compared with surgical findings, there were 6 false positive findings of meniscus perforation, the reliability of arthrographic findings of meniscus perforation was a 86.4% correlation with surgical findings. 6. On the site of perforations of 38 joints which were surgically confirmed perforation of meniscus or its attachments, twenty-three of perforations (60.5%) were in location at the junction of the meniscus and posterior attachment, forteen (36.9%) were located at the posterior attachment and one (2.6%) was at the meniscus itself.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.469-473
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• 2013

Background: The purpose of this study is to examine the risk of uncontrolled chemotherapy-induced nausea and vomiting (CINV) among patients receiving low emetogenic chemotherapy (LEC) with and without granisetron injection as the primary prophylaxis in addition to dexamethasone and metochlopramide. Materials and Methods: This was a single-centre, prospective cohort study. A total of 96 patients receiving LEC (52 with and 42 without granisetron) were randomly selected from the full patient list generated using the e-Hospital Information System (e-His). The rates of complete control (no CINV from days 1 to 5) and complete response (no nausea or vomiting in both acute and delayed phases) were identified through patient diaries which were adapted from the MASCC Antiemesis Tool (MAT). Selected covariates including gender, age, active alcohol consumption, morning sickness and previous chemotherapy history were controlled using the multiple logistic regression analyses. Results: Both groups showed significant difference with LEC regimens (p<0.001). No differences were found in age, gender, ethnic group and other baseline characteristics. The granisetron group indicated a higher complete response rate in acute emesis (adjusted OR: 0.1; 95%CI 0.02-0.85; p=0.034) than did the non-granisetron group. Both groups showed similar complete control and complete response rates for acute nausea, delayed nausea and delayed emesis. Conclusions: Granisetron injection used as the primary prophylaxis in LEC demonstrated limited roles in CINV control. Optimization of the guideline-recommended antiemetic regimens may serve as a less costly alternative to protect patients from uncontrolled acute emesis.

• The Journal of the Acoustical Society of Korea
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• v.25 no.3E
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• pp.101-109
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• 2006

Besides dorsal-aspect target strength (TS) of the fish, side-aspect TS information is also acoustically important parameter in fisheries acoustics. In this study, the side-aspect TS of 11 black sea bream (Acanthopagurus schlegeli) were measured using a split beam echosounder of 120, 200, and 420 kHz; total length of the fish ranged from 12.4 to 23.7 cm, and wet weight from 27.5 to 229.8g. For the precise TS measurement with side-aspect angle, we used anesthetized and tethered specimens of known size while being rotated through $360^{\circ}C$ by means of a carousel structure. The side-aspect TS measurements of the fish were conducted by rotating the fish in the horizontal plane at 50 interval. The ping interval was 0.2 second and elapsed time at each angle was 30-60 second. As a result, the measured side-aspect TS data were fitted by sinusoidal function. The relationships between fish length and near full side-aspect TS were as follows: $TS_{120kHz}= 21.46 log (TL)-67.5 (r = 0.70), \;TS_{200 kHz}= 31.03 log (TL)-76.9 (r=0.83),\;TS_{420 kHz}= 30.79 log (TL)-72.2 (r = 0.77)$. For comparison, theoretically estimated side-aspect TS from the Kirchhoff ray mode (KRM) model, which based on swimbladder and body morphology, were compared with the measured TS.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.25 no.3
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• pp.156-162
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• 2014

Objectives : The aim of this study was to estimate the prevalences of electroencephalographic (EEG) abnormalities and epilepsy in children and adolescents with autism spectrum disorder (ASD). In addition, we intended to identify demographic and clinical correlates of epilepsy in ASD. Methods : A total of 140 children and adolescents (age $7.3{\pm}4.8yrs$, 106 boys) with ASD underwent EEG from January 2010 to December 2013 at Asan Medical Center. Medical records were reviewed for demographic information, clinical characteristics, psychiatric diagnoses and comorbidities, EEG findings and neurological diagnoses. Results : The prevalences of EEG abnormalities and epilepsy in children and adolescents with ASD was 62.1% and 38.6%, respectively. In subjects with seizure-like movements, EEG abnormalities and epilepsy were more frequent than those without seizure-like movements (EEG abnormalities : 92.5% vs. 43.7%, p<.001 ; epilepsy : 90.6% vs. 5.7%, p<.001). ASD subjects who had epilepsy were older (p=.001), had lower full scale intelligence quotient (p<.001) and took more antipsychotics (p=.006) than those who did not. Conclusion : The prevalences of EEG abnormalities and epilepsy in our sample were similar to those from Western countries. Our results suggested a possible association of older age, lower intelligence quotient, and antipsychotics use with epilepsy in ASD. Conduct of further prospective study in a larger sample is needed.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.425-438
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• 2017

This study investigated the impacts of the experience attributes of JJALBANG broadcast images on satisfaction with 221 viewers in their 20s and analyzed the mediation effect of flow. The results are: First, their experience attributes affected flow, not directly affecting satisfaction while flow directly affected satisfaction. Second, securing flow was an important predictor for connecting experience attributes to satisfaction through the effect resolution. Flow alone can predict satisfaction, so its impact on experience is very important. Visual attribute had the greatest influence on flow and satisfaction, followed by situation, information, and interaction, which affected satisfaction through flow. This study found the importance of full mediation effect of flow and got implications for effectively providing experience and flow in strategies for viewing JJALBANG.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.3 s.357
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• pp.105-110
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• 2007

We have built the millimeter-wave passive imaging system with a lens and mechanical scan antenna. The lens was designed based on optical theory in order to focus millimeter-wane. A full image was taken from image points scanned by Placing antenna at the representative focal plane selectively. An integrated antenna array device for low-loss and low-noise with the array of 4 by 1, where components such as antenna, balun, MMIC, and detector were assembled on a sin91e substrate, and a fermi tapered slot antenna with high-gain and low-side lobe were used for elements of this millimeter-wave passive imaging system. Two dimensional antenna arrangement on focal plane was achieved in this imaging system.

• 전자공학회논문지 IE
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• v.44 no.4
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• pp.1-10
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• 2007

In this thesis, we study the implementation of hands-free phone in a car, taking acoustic echo canceller, in order to remove acoustic echo effectively. Conventional coustic echo canceller used for only adaptive filtering has much difficulty to solve both echo and double-talk problem. To tackle this problem, we propose acoustic echo canceller consisting of adaptive filter using a modified NLMS, VAD to catch exact voice activity duration using two independent forgetting factors, double-talk detector to detect fast and precise double talk duration using cross-correlation between microphone signal and residual echo, and output controller using VAD and double-talk detector. The proposed hands-free phone taking acoustic echo canceller shows the performance that has not acoustic echo and guarantees full duplex.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.9
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• pp.8-13
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• 2008

Noise in homogeneous extrinsic semiconductor samples is calculated due to distributed diffusion noise sources. As the length of the device shrinks at a fixed bias voltage, the ac-wise short-circuit noise current shows excess noise as well as thermal noise spectra. This excess noise behaves like a full shot noise when the channel length becomes very small compared with the extrinsic Debye length. For the first time, the analytic formula of the excess noise in extrinsic semiconductors from velocity-fluctuation noise sources is given for finite frequencies. This formula shows the interplay between transit time, dielectric relaxation time, and velocity relaxation time in determining the terminal noise current as well as the carrier density fluctuation. As frequency increases, the power spectral density of the excess noise rolls off. This formula sheds light on noise in nanoscale MOSFETs where quasi-ballistic transport plays an important role in carrier transport and noise.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.1
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• pp.66-70
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• 2017

Radioactive materials are used in medicine, non-destructive testing, and nuclear plants. Source localization is especially important during nuclear decommissioning and decontamination because the actual location of the radioactive source within nuclear waste is often unknown. The coded-aperture imaging technique started with space exploration and moved into X-ray and gamma ray imaging, which have imaging process characteristics similar to each other. In this study, we simulated $21{\times}21$ and $37{\times}37$ coded aperture collimators based on a modified uniformly redundant array (MURA) pattern to make a gamma imaging system that can localize a gamma-ray source. We designed a $21{\times}21$ coded aperture collimator that matches our gamma imaging detector and did feasibility experiments with the coded aperture imaging system. We evaluated the performance of each collimator, from 2 mm to 10 mm thicknesses (at 2 mm intervals) using root mean square error (RMSE) and sensitivity in a simulation. In experimental results, the full width half maximum (FWHM) of the point source was $5.09^{\circ}$ at the center and $4.82^{\circ}$ at the location of the source was $9^{\circ}$. We will continue to improve the decoding algorithm and optimize the collimator for high-energy gamma rays emitted from a nuclear power plant.