이원종 교수

This paper investigates the problem of dynamic multiuser subchannel allocation in the downlink of OFDM systems. The assumptions are that the channel model is quasi-static and that the base station has perfect channel information. In traditional TDMA or FDMA systems, resource allocation for each user is non-adaptively fixed, and the water-filling power spectrum is known to be optimal. Since the subchannel allocations among the users are not optimized, a group of users is likely to suffer from poo

The advantages of multiuser communication, where many users are allowed to simultaneously transmit or receive in a common bandwidth, are considered for multiple-antenna systems in a high signal-to-noise ratio (SNR) regime. Assuming channel state information at receiver (CSIR) to be available, the ergodic capacity is characterized for both unbiased and biased channels, and the quantitative capacity gain of a multiple-antenna multiuser system is analyzed for multiple-access channels. For highly bi

Although promising results of high-performance AI algorithms have been reported in recent predictive maintenance researches, most of the existing studies merely deal with AI-only solutions and do not consider the interaction between humans and AI. In this study, we explicitly focus on the benefits of interactions where a human inspector is assisted by AI solutions. A case study is conducted for predictive maintenance of wind farms, where endoscopic images were used for bearing fault detection. T

Internet-connected devices, especially mobile devices such as smartphones, have become widely accessible in the past decade. Interaction with such devices has evolved into frequent and short-duration usage, and this phenomenon has resulted in a pervasive popularity of casual games in the game sector. On the other hand, development of casual games has become easier than ever as a result of the advancement of development tools. With the resulting fierce competition, now both acquisition and retent

Recently, with the increasing demand for photorealistic graphics and the rapid advances in desktop CPUs/GPUs, real-time ray tracing has attracted considerable attention. Unfortunately, ray tracing in the current mobile environment is very difficult because of inadequate computing power, memory bandwidth, and flexibility in mobile GPUs. In this paper, we present a novel mobile GPU architecture called SGRT (Samsung reconfigurable GPU based on Ray Tracing) in which a fast compact hardware accelerat

This paper considers the optimal uplink transmission strategy that achieves the sum-capacity in a multiuser multi-antenna wireless system. Assuming an independent identically distributed block-fading model with transmitter channel side information, beamforming for each remote user is shown to be necessary for achieving sum-capacity when there is a large number of users in the system. This result stands even in the case where each user is equipped with a large number of transmit antennas, and it

Energy disaggregation, or nonintrusive load monitoring (NILM), is a technology for separating a household’s aggregate electricity consumption information. Although this technology was developed in 1992, its practical usage and mass deployment have been rather limited, possibly because the commonly used datasets are not adequate for NILM research. In this study, we report the findings from a newly collected dataset that contains 10 Hz sampling data for 58 houses. The dataset not only contains the

This study was conducted to investigate the possibility of using brown rice as a raw material for preparation of sikhe. The activity of germinated brown rice was much lower than that of germinated barley; however, the extract and its sugar content of extract prepared from germinated brown rice was similar to those of germinated barley. The extract of sikhe prepared with brown rice at for 4 hr was similar to that of milled rice for 1 hr. Sikhe prepared with brown rice did not differ from sikhe pr

In this paper, the ergodic capacity region of multi-antenna multiple-access channels is derived, and the quantitative capacity gains of multiuser communication systems are investigated. In many multi-antenna communication scenarios, the ergodic capacity of multiuser systems, where many users are allowed to simultaneously transmit or receive in a common bandwidth, is shown to be significantly larger than that of single user systems.