• Korean Journal of Radiology
• /
• v.23 no.12
• /
• pp.1269-1280
• /
• 2022

Objective: This study aimed to evaluate the usefulness of quantitative indices obtained from deep learning analysis of gadoxetic acid-enhanced hepatobiliary phase (HBP) MRI and their longitudinal changes in predicting decompensation and death in patients with advanced chronic liver disease (ACLD). Materials and Methods: We included patients who underwent baseline and 1-year follow-up MRI from a prospective cohort that underwent gadoxetic acid-enhanced MRI for hepatocellular carcinoma surveillance between November 2011 and August 2012 at a tertiary medical center. Baseline liver condition was categorized as non-ACLD, compensated ACLD, and decompensated ACLD. The liver-to-spleen signal intensity ratio (LS-SIR) and liver-to-spleen volume ratio (LS-VR) were automatically measured on the HBP images using a deep learning algorithm, and their percentage changes at the 1-year follow-up (ΔLS-SIR and ΔLS-VR) were calculated. The associations of the MRI indices with hepatic decompensation and a composite endpoint of liver-related death or transplantation were evaluated using a competing risk analysis with multivariable Fine and Gray regression models, including baseline parameters alone and both baseline and follow-up parameters. Results: Our study included 280 patients (153 male; mean age ± standard deviation, 57 ± 7.95 years) with non-ACLD, compensated ACLD, and decompensated ACLD in 32, 186, and 62 patients, respectively. Patients were followed for 11-117 months (median, 104 months). In patients with compensated ACLD, baseline LS-SIR (sub-distribution hazard ratio [sHR], 0.81; p = 0.034) and LS-VR (sHR, 0.71; p = 0.01) were independently associated with hepatic decompensation. The ΔLS-VR (sHR, 0.54; p = 0.002) was predictive of hepatic decompensation after adjusting for baseline variables. ΔLS-VR was an independent predictor of liver-related death or transplantation in patients with compensated ACLD (sHR, 0.46; p = 0.026) and decompensated ACLD (sHR, 0.61; p = 0.023). Conclusion: MRI indices automatically derived from the deep learning analysis of gadoxetic acid-enhanced HBP MRI can be used as prognostic markers in patients with ACLD.

• Proceedings of the KIPE Conference
• /
• 2000.07a
• /
• pp.245-248
• /
• 2000

In this paper a novel method for voltage disturbance detection is presented. This is a instantaneous detection method using normalized error get in synchronous reference frame and also it is implemented in digital. Feedback noise the problem of digital implementation is removed by a digital filter of which the time delay is compensated through numerical analysis.

• Proceedings of the Optical Society of Korea Conference
• /
• 2001.08a
• /
• pp.104-105
• /
• 2001

• Proceedings of the Optical Society of Korea Conference
• /
• 2006.02a
• /
• pp.233-234
• /
• 2006

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1984.10a
• /
• pp.92-95
• /
• 1984

This paper describes the output P.D.F. of various Compandors, optimum, -law and A-law for the Gaussian and Laplacian Density as an input analog signal. Also we consider the truncated densities compensated by weighted impulse or density coefficient.

• Journal of the Korean Solar Energy Society
• /
• v.32 no.spc3
• /
• pp.282-288
• /
• 2012

Proton exchange membrane fuel cell (PEMFC) is the most promising energy source for the robot applications because it has unique advantages such as high energy density, no power drop during operating, and easy to make compact size. However, PEMFC has intrinsic disadvantages which are delay to start up and difficulty to correspond drastic load changes. These disadvantages can be compensated by hybrid operating with a Li-poly battery. This study is focus to build and understand the hybrid system for the robot system. In this study, we build the PEMFC hybrid system using EOS-320 PEMFC stack, Li-poly battery and G-Philos FDX1-250BU dc-dc converter. The hybrid system is accurately monitored by CAN and RS485. The system was studied under two conditions such as non-loaded and loaded operating conditions. The results show that the system has delay to start up without hybrid operating and it can be compensated with the hybrid operating.

• Safety and Health at Work
• /
• v.3 no.1
• /
• pp.67-70
• /
• 2012

The surveillance programme of work-related diseases (WRD) is based on a network of occupational physicians who notify all WRD diagnosed during a two-week observation period. The aims are mainly to estimate the prevalence of non-compensated WRD in the working population according to socio economic factors; to determine new indicators of occupational health; to update the lists of compensable occupational diseases; to understand and assess under-compensation and under-notification. The participation rate for occupational physicians is around 33% in 2008. The main WRD are the musculoskeletal disorders, followed by the mental disorders. This 2-week protocol, repeated regularly, provides useful data on frequency of pathologies linked to employment as well as an estimate of unreported WRD subject to compensation or non-compensated WRDs, and the trends of WRDs over the time.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.1
• /
• pp.61-70
• /
• 2004

In this paper, we propose the color-temperature conversion system with compensated X-chromaticity coordinate. It uses a linear regression to improve the error of color-temperatue calculation in conventional systems. It also extend the color-temperature range from 1,667K to 25,000K to Provide a wider color-temperature range. We show the effectiveness of the proposed method by comparing the performance of the proposed method with those of the Robertson's and the existing methods. The proposed method is experimetally verified by displaying the results on a TV system through the Xilinx FPGA XCV2000E-BG560.

• Proceedings of the KIPE Conference
• /
• 2011.11a
• /
• pp.71-72
• /
• 2011

This paper presents a novel and direct dead time compensation method of the 3 phase inverter using space vector pulse width modulation(SVPWM) topology. In the turn on time calculation of the effective voltage, the dead time effect is directly compensated according to the current direction of the midium voltage reference. Since the turn on time of the effective voltage vector is affected by the dead time, the loss time is compensated to turn on time of the effective voltage vector. And the dead time is added to the calculated voltage vector switching times according to the current direction. For the more effective compensation, the direction of the midium phase current is considered by the practical direction and voltage drops in the power devices. The proposed method can compensate the dead time which is considered feedback error or direction of middle phase current without coordinate transform in added controller. The proposed dead time compensation scheme is verified by the computer simulation and experiments of 3 phase R L load.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.673-675
• /
• 2004

This study proposes controller with voltage-compensated drivers for producing gray-scaled pictures on passive matrix organic light emitting diodes (PMOLEDs) panels. The controller includes voltage type drivers so the output impedance of the driver is far less than that of the current-type driver. Its low output impedance provides better electron-optical properties than those of traditional current drivers. A free running clock and a group of counters are applied to the gray-scaled function so that phase lock loop (PLL) circuit can be reduced in the controller. A pre-charge function is used to enhance performance of the luminance of an active OLED pixel. As a result, distribution of the low gray level portion is achieved linear relationship with input data. In this work, the digital part of the proposed controller is implemented using FPGA chips, and analog parts are combined with a digital-analog converter (DAC) and analog switches. A still image is displayed on a $48^{\ast}64$ PMOLEDs panel to assess the luminance performance fir the controller. Based on its cost requirement and luminance performance, the controller is qualified to join the market for driving PMOLEDs panels.