Doo Hwan Lee

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Ranging process is proposed for the coordination between mobile station and base station in IEEE 802.16e OFDMA systems. It consists of ranging detection process (RDP), uplink resource allocation, and registration. Among them, RDP is the first step of ranging process and the core of wireless access algorithm in IEEE 802.16e OFDMA systems. Thus, it is(More)
BACKGROUND AND OBJECTIVES Predictive factors of mortality in acute coronary syndrome (ACS) patients with left ventricular dysfunction were analyzed during 5-year clinical follow-up after percutaneous coronary intervention (PCI). SUBJECTS AND METHODS A total of 329 ACS consecutive patients (64.6±11.3 years, 227 males) who underwent PCI from January 2001 to(More)
The aim of this study was to evaluate whether the clinical outcomes were associated with socioeconomic status (SES) in patients with acute myocardial infarction (AMI) who underwent percutaneous coronary intervention (PCI). The author analyzed 2,358 patients (64.9 ± 12.3 yr old, 71.5% male) hospitalized with AMI between November 2005 and June 2010. SES was(More)
To reduce the complexity of scheduling while exploiting the advantages of TDMA-based data collection, we propose TKN-TWN, a token-scheduled multi-channel data collection protocol. The TKN-TWN uses two tokens to arbitrate data-packet transmissions and associates the ownership of tokens with transmission slot assignment. For the reduction of scheduling(More)
This paper presents a preambleless communication system to realize industrial wireless control networks (WCN) which are characterized by short payloads and strict real-time requirements. The reduction of the preamble is greatly beneficial for the real-time operation because the transmission time of preambles is longer than that of the short payloads. Our(More)
— Random access process of LTE (long term evolution) system is carried out exploiting the superior correlation property of random access code. Each user unit transmits randomly selected random access code, and the Node B (base station) detects each code by correlating the received signal with all possible random access codes. By comparing the correlation(More)