Publications by authors named "Chang Jae Lee"

The condition of a railway vehicle's wheels is an essential factor for safe operation. However, the current inspection of railway vehicle wheels is limited to periodic major and minor maintenance, where physical anomalies such as vibrations and noise are visually checked by maintenance personnel and addressed after detection. As a result, there is a need for predictive technology concerning wheel conditions to prevent railway vehicle damage and potential accidents due to wheel defects.

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This paper presents the implementation of a pulse-type LAser Detection And Ranging (LADAR) system based on heterodyne detection for long-range measurement. A pulse-type LADAR based on an intensity direct-detection is certainly simple and mature, but it requires a high peak-power laser and a low-noise avalanche photodiode for long-range measurement, which restricts the scope of the application due to the weight, power consumption, and cost of the laser and the photodetector. In this work, heterodyne detection using a PIN photodiode is implemented to increase receiver sensitivity instead of using a low-noise avalanche photodiode.

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Objective: Current guidelines for cardiopulmonary resuscitation recommend chest compressions (CC) during 50% of the duty cycle (DC) in part because of the ease with which individuals may learn to achieve it with practice. However, no consideration has been given to a possible interaction between DC and depth of CC, which has been the subject of recent study. Our aim was to determine if 50% DC is inappropriate to achieve sufficient chest compression depth for female and light rescuers.

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Background/aims: Patients with diabetes mellitus (DM) are more likely to have a pyogenic liver abscess with gas formation, which is associated with higher morbidity and mortality. The morbidity and mortality in pyogenic liver abscess are also higher in DM patients than in non-DM patients. This study evaluated the morbidity, mortality, and clinical features in patients with gas-forming liver abscesses associated with DM.

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Background/aims: Klebsiella pneumoniae is emerging as the leading cause for liver abscess although the most common pathogen was Escherichia coli in the past. Patients with diabetes mellitus are more likely to have a pyogenic liver abscess with gas forming infection; a gas forming pyogenic liver abscess carries a higher morbidity and mortality than the non-gas forming group. This study was conducted to clarify the clinical presentation and prognostic factors for pyogenic liver abscess in diabetic patients compared with non-diabetic patients.

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