A5102815394- Electric Motor Design and Analysis
- Magnetic Bearings and Levitation Dynamics
- Image and Video Quality Assessment
- Magnetic Properties and Applications
- Cultural and Historical Studies
- Video Coding and Compression Technologies
- Educational Systems and Policies
- Electric and Hybrid Vehicle Technologies
- Sensorless Control of Electric Motors
- Advanced Data Compression Techniques
- Non-Destructive Testing Techniques
- Advanced Image Processing Techniques
- Diverse Topics in Contemporary Research
- Education and Learning Interventions
- Visual perception and processing mechanisms
- Advanced Optical Imaging Technologies
- Mechanical Engineering and Vibrations Research
- Image Enhancement Techniques
- Machine Fault Diagnosis Techniques
- BIM and Construction Integration
- Ophthalmology and Visual Impairment Studies
- Manufacturing Process and Optimization
- Engineering Applied Research
- Korean Peninsula Historical and Political Studies
- Advanced Wireless Network Optimization
Hanyang University
2019-2024
Samsung (South Korea)
2023
Keimyung University
2015-2016
Yonsei University
2007-2014
University of Ottawa
2002
It is generally recognized that severe video distortions are transient in space and/or time have a large effect on overall perceived quality. In order to understand this phenomena, we study the distribution of spatio-temporally local quality scores obtained from several assessment (VQA) algorithms videos suffering compression and lossy transmission over communication channels. We propose content adaptive spatial temporal pooling strategy based observed distribution. Our method adaptively...
Being able to predict the degree of visual discomfort that is felt when viewing stereoscopic 3D (S3D) images an important goal toward ameliorating causative factors, such as excessive horizontal disparity, misalignments or mismatches between left and right views stereo pairs, conflicts different depth cues. Ideally, a model should account for factors capture geometries, distribution disparities, responses neurons. When modern displays, caused primarily by changes in binocular vergence while...
To achieve clear binocular vision, neural processes that accomplish accommodation and vergence are performed via two collaborative, cross-coupled processes: accommodation-vergence (AV) vergence-accommodation (VA). However, when people watch stereo images on stereoscopic displays, normal functioning may be disturbed owing to anomalies of the cross-link gains. These likely main cause visual discomfort experienced viewing images, called Accommodation-Vergence Mismatches (AVM). Moreover, absence...
This article proposes an indirect method for predicting mechanical loss by considering the eddy current of permanent magnets (PMs) and conductors under no-load condition. The has been conventionally predicted indirectly through experiments numerical methods. conventional uses measured iron calculated a method. With increase in demand high-power-density motors, PMs with high energy density winding technology fill factor are required. Thus, proportion losses is increasing among electromagnetic...
The tremendous explosion of image-, video-, and audio-enabled mobile devices, such as tablets smart-phones in recent years, has led to an associated dramatic increase the volume captured distributed multimedia content. In particular, number digital photographs being annually is approaching 100 billion just U.S. These pictures are increasingly acquired by inexperienced, casual users under highly diverse conditions leading a plethora distortions, including blur induced camera shake. order be...
To be used as a robotic actuator, surface-mounted permanent magnet synchronous motor (SPMSM) requires low cogging torque characteristic. The aim of this study is to analyze and reduce the torque's variation due assembly imperfection segmented stator that widely in SPMSM. Considering interconnection segments, an equivalent modeling method with introduced. In addition, caused by mathematically evaluated. Then, robust design process incorporates sensitivity analysis optimization proposed. By...
To achieve seamless multimedia streaming services over wireless networks, it is important to overcome inter-cell interference (ICI), particularly in cell border regions. In this regard scalable video coding (SVC) has been actively studied due its advantage of channel adaptation. We explore an optimal solution for maximizing the expected visual entropy orthogonal frequency division multiplexing (OFDM)-based broadband network from perspective cross-layer optimization. An optimization problem...
We describe a method for achieving perceptually minimal video distortion over packet-erasure networks using unequal loss protection (PULP). There are two main ingredients in the algorithm. First, perceptual weighting scheme is employed wherein compressed weighted as function of nonuniform distribution retinal photoreceptors. Secondly, packets assigned temporal importance within each group pictures (GOP), recognizing that severity error propagation increases with elapsed time GOP. Using both...
This article proposes a method to suppress the torque ripple caused by misalignment of gearbox. Misalignment is common fault manufacturing tolerances, and generates ripple. Therefore, even if constant electromagnetic transmitted from motor gearbox, large may be load because misalignment. In proposed method, harmonic current injection in which injected into armature current, used produced The amplitude phase are calculated using ripple, for estimating does not require sensor, has been...
Owing to the high speed and frequency required in electric machine industry, significance of ac resistance has been increasing. This study investigates windings according configuration strands. The mechanism generating winding conductors was investigated with respect slot leakage flux eddy current. Then, when applying strands winding, concept unbalanced impedance introduced characterize additional due circulating analytic method calculate describing above phenomena is derived verified by FEA...
In this article, the electrical and mechanical characteristics of multilayer interior permanent magnet synchronous motors (ML-IPMSMs) using ferrite magnets (PMs) are compared when driven at high speeds with respect to type steel. high-speed operation, ML-IPMSMs vary depending on number PM layers, shape, bridges, bridge thickness. addition, PMs have a lower coercive force than neodymium (Nd) PMs; therefore, irreversible demagnetization (ID) must be considered, it is affected by layers shape...
With the increasing popularity of video applications, reliable measurement perceived quality has increased in importance. We study methods for pooling scores over space and time. The method accounts localized severe impairments signal which exhibit significant influence on subjective impression overall quality. It also effect camera motion (egomotion) arrived at is tested LIVE Video Quality Database shown to perform quite well.
Emerging multimedia applications have increased the need for video quality measurement. Motion is critical to this task, but complicated owing a variety of object movements and movement camera. Here, we categorize various motion situations deploy appropriate perceptual models each category. We use these create new approach objective assessment. Performance evaluation on Laboratory Image Video Engineering (LIVE) Quality Database shows competitive performance compared leading contemporary VQA...
We propose a novel visual scalable video coding (VSVC) framework, named VSVC H.264/AVC. In this approach, the non-uniform sampling characteristic of human eye is used to modify (SVC) exploit visibility content and scalability codec achieve optimal subjective quality given limited system resources. To largest gain with controlled perceptual degradation, weighting scheme deployed wherein compressed weighted as function saliency distribution retinal photoreceptors. develop resource allocation...
Static eccentricity (SE) is frequently generated by manufacturing processes. As the nonuniformity of air-gap length caused SE, torque ripple and cogging increase in motor. This study analyzes distorted back electromotive force (EMF) due to SE. Further, a motor design considering SE performed for stable EMF low torque. First, was diagnosed analyzed using measured from test results base model. In addition, rotor position calculated unbalanced The used when analyzing phenomena applied robust...
Many studies have been conducted to reduce the cogging torque of electric power steering motors. However, in mass production such motors, it is essential enhance performance robustness relation tolerances. For this work analyzes tolerances by applying a cycloid curve surface magnet rotor. Applying rotor one several ways torque. To evaluate curve, we compare with an eccentric curve. The two curves are compared for same specifications and evaluated using indicator, tolerance insensitivity...
In the interior permanent magnet synchronous motor (IPMSM), an asymmetric rotor is used as a design method to reduce torque ripple or cogging by adjusting saturation of core. The advantage that it can in forward direction while maintaining average output power. However, when driving reverse direction, be increased. Therefore, produces different characteristics and directions. this study, shape designed using optimization technique taking into consideration rotating direction. optimum...
In the interior permanent magnet synchronous motor (IPMSM), an asymmetric rotor is used as a design method to reduce torque ripple or cogging by adjusting saturation of core. The advantage that it can in forward direction while maintaining average output power. However, when driving reverse direction, be increased. Therefore, produces different characteristics and directions. this study, shape designed using optimization technique taking into consideration rotating direction. optimum...
In order to utilize the liquid crystal display (LCD) overdrive technique, it is necessary store previous frame in memory and compress reduce burden, particular, when size large. When an image displayed LCD, motion blur mainly occurs near edge, so that structural information very important compressing image. Recently, a similarity (SSIM) index has been proposed measure quality based on structure. this paper, we propose compression adaptive mode selection algorithm for maximizing SSIM...
We seek a resource allocation algorithm through carrier and modulation mode selection for improving the quality of service (QoS) that can adapt to various screen sizes dynamic channel variations. In terms visual quality, expected entropy (EVE) is defined quantify information being contained in each layer scalable video coding (SVC). Fairness optimization conducted maximize EVE using an objective function given constraints radio resources. To conduct fairness optimization, we propose novel...
Background Despite improved long-term safety of biodegradable polymer (BP) drug-eluting stents (DES) compared to first-generation durable (DP) DES, data on the and efficacy BP-DES with second-generation (2G) DP-DES in patients acute myocardial infarction (AMI) are limited. Hypothesis To evaluate 2G-DP-DES higher stent thrombosis (ST) risk setting AMI. Methods A total 3359 AMI who received either (n = 261) or 3098) were included from Korea Acute Myocardial Infarction Registry (KAMIR)....