http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Soomin Ko,Seungmin Lee,Hojoong Kwon,Byeong Gi Lee IEEE 2010 IEEE Transactions on Wireless Communications Vol.9 No.9
<P>In this paper, we present two new feedback schemes, namely the network mode selection-based feedback (NMF) and the user mode selection-based feedback (UMF), that reduce the feedback load needed for opportunistic scheduling in the OFDMA downlink system. The two schemes are designed to select either the selective feedback (SF) mode which feeds back the fine-grained condition of a part of the channels or the bit-map based feedback (BF) mode which feeds back the coarse-grained condition of all the channels using 1 bit for each channel, depending on the channel conditions of the users. Specifically, the NMF scheme makes the BS determine the more desirable feedback mode by predicting and comparing the average total throughputs of the two modes for the given statistical channel characteristics of the users. The UMF scheme makes each user determine its own feedback mode based on both its channel realization and the recommendation of the network. Numerical results reveal that the proposed NMF and UMF schemes achieve significant performance gain over the existing feedback reduction schemes with similar feedback load.</P>
Ko, Soomin,Lee, Jungsu,Lee, Byeong Gi,Park, Daeyoung The Korea Institute of Information and Commucation 2013 Journal of communications and networks Vol.15 No.6
In this paper, we propose a new feedback scheme called mode selection-based feedback by scheduling probability prediction (SPP-MF) for channel state feedback in OFDMA downlink system. We design the scheme such that it determines the more desirable feedback mode among selective feedback by scheduling probability prediction (SPP-SF) mode and bitmap feedback by scheduling probability prediction (SPP-BF) mode, by calculating and comparing the throughputs of the two modes. In both feedback modes, each user first calculates the scheduling probability of each subchannel (i.e., the probability that a user wins the scheduling competition for a subchannel) and then forms a feedback message based on the scheduling probability. Specifically, in the SPP-SF mode, each user reports the modulation and coding scheme (MCS) levels and indices of its best S subchannels in terms of the scheduling probability. In the SPP-BF mode, each user determines its scheduling probability threshold. Then, it forms a bitmap for the subchannels according to the scheduling probability threshold and sends the bitmap along with the threshold. Numerical results reveal that the proposed SPP-MF scheme achieves significant performance gain over the existing feedback schemes.
Distributed Uplink Resource Allocation in Multi-Cell Wireless Data Networks
Soomin Ko,Hojoong Kwon,Byeong Gi Lee 한국통신학회 2010 Journal of communications and networks Vol.12 No.5
In this paper, we present a distributed resource allocation algorithm for multi-cell uplink systems that increases the weighted sum of the average data rates over the entire network under the average transmit power constraint of each mobile station. For the distributed operation, we arrange each base station (BS) to allocate the resource such that its own utility gets maximized in a noncooperative way. We define the utility such that it incorporates both the weighted sum of the average rates in each cell and the induced interference to other cells, which helps to instigate implicit cooperation among the cells. Since the data rates of different cells are coupled through inter-cell interferences, the resource allocation taken by each BS evolves over iterations. We establish that the resource allocation converges to a unique fixed point under reasonable assumptions. We demonstrate through computer simulations that the proposed algorithm can improve the weighted sum of the average rates substantially without requiring any coordination among the base stations.
Evolution of Inter-Cell Interference Management in Next-Generation Wireless Communication Systems
Hojoong Kwon,Soomin Ko,Hanbyul Seo,Byeong Gi Lee 대한전자공학회 2008 ICEIC:International Conference on Electronics, Inf Vol.1 No.1
In this paper, we investigate how the inter-cell interference management should evolve in the next-generation systems. A new paradigm has been created in inter-cell interference management due to the advent of the next-generation wireless communication systems. The main driving force involves datacentric services, new dynamic service scenarios, all-IP core access networks, and new physical-layer technologies. We establish that the next-generation inter-cell interference management should 1) set the objective of providing a maximal data rate, 2) take the form of joint management of power allocation and user scheduling, 3) operate in a fully distributed manner, and 4) deal with the change in interference mechanism triggered by the new physical-layer technologies.
스마트스피커 기반 인터랙티브 콘텐츠 사용 행태에 대한 탐색적 연구
고병휘(Byunghi Ko),이정복(Jeongbok Lee),이수민(Soomin Lee),이중식(Joongseek Lee) 한국HCI학회 2020 한국HCI학회 학술대회 Vol.2020 No.2
아마존 에코, 구글홈 등의 다양한 스마트스피커가 확산되면서 제 3 자 개발 서비스도 증가하고 있다. 이러한 서비스에는 기존처럼 한번의 요청에 한번의 응답을 제공하고 종료하는 경우도 있지만, 여러번의 인터랙션이 오고 가거나 제공되는 콘텐츠 자체의 길이가 길어진 인터랙티브 콘텐츠가 다수 존재한다. 이러한 서비스의 경우 사용자가 이용 중간에 주의를 놓쳐 인터랙션 타이밍을 놓치는 경우가 많아 문제가 발생한다. 본 연구는 이러한 사용자의 무응답의 원인을 파악하고 대응하기 위한 연구이다. 우선 매일 큐레이션된 클래식 음악을 설명과 함께 제공하는 구글홈 기반의 대화형 서비스를 개발하였다. 25 명을 대상으로 15 일간 사용하도록 했고, 사용 로그를 정리하고 분석한 결과, 전체 인터랙션 중 19.68%가 이러한 무응답 문제가 발생했다. 이러한 문제의 이유는 크게 네 가지였다. 본 연구는 해당 문제가 발생하는 원인들을 파악하고, 이를 해결하기 위한 디자인을 제언한다는 점에서 의의가 있다.
Inter-Cell Interference Management for Next-Generation Wireless Communication Systems
Hojoong Kwon,Soomin Ko,Hanbyul Seo,이병기 한국통신학회 2008 Journal of communications and networks Vol.10 No.3
In this paper, we examine what changes the nextgeneration wireless communication systems will experience in terms of the technologies, services, and networks and, based on that, we investigate how the inter-cell interference management should evolve in various aspects.We identify that the main driving forces of the future changes involve the data-centric services, new dynamic service scenarios, all-IP core access networks, new physical-layer technologies, and heavy upload traffic. We establish that in order to cope with the changes, the next-generation intercell interference management should evolve to 1) set the objective of providing a maximal data rate, 2) take the form of joint management of power allocation and user scheduling, 3) operate in a fully distributed manner, 4) handle the time-varying channel conditions in mobile environment, 5) deal with the changes in interference mechanism triggered by the new physical-layer technologies, and 6) increase the spectral efficiency while avoiding centralized coordination of resource allocation of the users in the uplink channel.