Kyungtae Kang

Respiratory sounds are expressed as nonlinear and nonstationary signals, whose unpredictability makes it difficult to extract significant features for classification. Static cepstral coefficients such as Mel-frequency cepstral coefficients (MFCCs), have been used for classification of lung sound signals. However, they are modeled in high-dimensional hyperspectral space, and also lose temporal dependency information. Therefore, we propose shifted [Formula: see text]-cepstral coefficients in lower

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The cdma2000 1<formula formulatype="inline"><tex>$\times$</tex></formula>evolution-data-only (EV-DO) mobile communication system provides broadcast and multicast services (BCMCS) to meet an increasing demand for multimedia data services. Currently, broadcast and multicast streams are scheduled using a slot-based static algorithm which cannot support dynamic environments where broadcast content is add

We propose a model-based description and analysis framework for the design of wireless system architectures. Its aim is to address the shortcomings of existing approaches to system verification and the tracking of anomalies in safety-critical wireless systems. We use Architecture Analysis and Description Language (AADL) to describe an analysis-oriented architecture model with highly modular components. We also develop the cooperative tool chains required to analyze the performance of a wireless

The broadcast and multicast services (BCMCS) protocol is designed for real-time applications such as MPEG-4 video streaming, which requires successive frames to arrive within a specific time interval. We analyze the execution time of Reed-Solomon (RS) decoding, which is the medium access control (MAC)-layer forward error-correction (FEC) scheme used in CDMA2000 1xEV-DO BCMCS, under various air channel conditions. The results show that the timing constraints of MPEG-4 cannot always be met by RS d

Scalable video transmission over a network is easily adaptable to different types of mobile experiencing different network conditions. However the transmission of differentiated video packets in an error-prone wireless environment remains problematic. We propose and analyze a cross-layer error control scheme that exploits priority-aware block interleaving (PBI) in the MAC layer for video broadcasting in CDMA2000 systems. The PBI scheme allocates a higher priority to protecting the data which are

The importance of the misframe times for DS1 frame synchronization has often been addressed in designing and using network elements and mediation units. By extending the work of J. H. Eu and W. W. Rollins (1991), Markov chain first passage time analysis is used to derive higher moments of the misframe times in both random and burst error environments. This methodology is of great value in evaluating frame synchronization techniques for digital transmission systems. By experimenting with several

Quality of service (QoS) and, in particular, reliability and a bounded low latency are essential attributes of safety-critical wireless systems for medical applications. However, wireless links are typically prone to bursts of errors, with characteristics which vary over time.We propose a wireless system suitable for real-time remote patient monitoring in which the necessary reliability and guaranteed latency are both achieved by an efficient error control scheme. We have paired an example remot

This work provides a guide to the systematic design of an intelligent classification system for decision support in Holter ECG monitoring.

A wireless electrocardiogram case study suggests that current CDMA2000 cellular technology has considerable potential in medical telemetry. Modifications to the network protocol stack ensure the highest data integrity and lowest service delay.

Obstructive sleep apnea (OSA), a prevalent sleep disorder, is intimately associated with various other diseases, particularly cardiovascular conditions. The conventional diagnostic method, nocturnal polysomnography (PSG), despite its widespread use, faces challenges due to its high cost and prolonged duration. Recent developments in electrocardiogram-based diagnostic techniques have opened new avenues for addressing these challenges, although they often require a deep understanding of feature en

The recent development of high-speed data transmission over wireless cellular networks has enabled the delivery of multimedia broadcasting services to mobile users. These services involve a range of interactions among different system components, including the wireless channel, the network, and mobile devices, making it crucial for the service provider to verify the model, design, and behavior of a new service before it is deployed. However, previous studies have largely relied on network simula

cdma2000 1/spl times/EV-DO, one of the prominent 3G mobile communication systems, provides broadcast and multicast services (BCMCS) to meet increasing demand for multimedia data services. Currently, 1/spl times/EV-DO schedules broadcast streams using a slot-based static algorithm, which fails to support dynamic environments where broadcast content is added or removed on-line. We propose a dynamic packet-scheduling algorithm that works with a retransmission scheme for the BCMCS scheduler. Integra