• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.8 no.4
• /
• pp.25-33
• /
• 2008

The performance of power constrained cooperative multi-relay system with/without opportunistic transmission is considered in Rayleigh fading. The three power allocation methods are considered to maximize the system performance when the total network power is limited. It is analyzed that the opportunistic power allocation strategy has the best performance enhancement compared to the other power allocation strategies. The opportunistic relays increases with the total network power, which induce the higher diversity order of the opportunistic cooperative diversity, consequently improves the end-to-end outage probability.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.9 no.6
• /
• pp.1-8
• /
• 2009

Though the wireless ad-hoc network which is recently highly focused is power limited network, one of the main research topic is power saving. We propose a optimal power allocation strategy and derive the optimal power of the opportunistic transmission relays for minimum outage probability of the power limited network. It is shown that the proposed optimal power allocation has always better performance than that of the equal power allocation.

• Journal of Communications and Networks
• /
• v.10 no.2
• /
• pp.194-203
• /
• 2008

This paper considers the multi-input multi-output (MIMO) relay channel where multiple antennas are employed by each terminal. Compared to single-input single-output (SISO) relay channels, MIMO relay channels introduce additional degrees of freedom, making the design and analysis of optimal cooperative strategies more complex. In this paper, a partial cooperation strategy that combines transmit-side message splitting and block-Markov encoding is presented. Lower bounds on capacity that improve on a previously proposed non-cooperative lower bound are derived for Gaussian MIMO relay channels.

• Journal of IKEEE
• /
• v.22 no.2
• /
• pp.402-407
• /
• 2018

Link selection strategy has been an important technical issues of relay network. In this paper, we introduce a link selection scheme in the bidirectional, buffer-aided relay network. Three kinds of information such as the states of the queue at the relay buffer, the qualities of the links, and the states of the queues at the user buffer are considered. Throughput and delay performance is evaluated under three cases with different available information.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.166.5-166
• /
• 2001

In the teleoperation system, force, position and velocity signals are communicated between master and slave arm. The addition of force feedback for the teleoperation system benefits the operator by providing more information to perform given tasks especially for tasks requiring contact with environment. When the master and slave arms are located in different places, time delay is unavoidable. Also it is well known that the system can become unstable when a time delay exists in the communication channel. The proposed control strategy is to use predictive control method(MBPC). The predictive controller is used to control teleoperation´s position and force control. Also it is used to overcome time delay.

• Journal of the Korea Society for Simulation
• /
• v.8 no.4
• /
• pp.33-51
• /
• 1999

In this study, the system level network simulation is considered with adaptive array antenna in CDMA mobile communication system. A network simulation framework is implemented based on IS-95A/B system to consider dynamic handoff, system level network behavior, and deploying strategy into the overall CDMA mobile communication network under adaptive array algorithm. Its simulation model, such as vector channel model, adaptive beam forming antenna model, handoff model, and power control model, are described in detail with simulation block. In order to maximize SINR of received signal at antenna, Maximin algorithm is particularly considered, and it is computed at each simulation snap shot with SINR based power control and handoff algorithm. Graphic user interface in this system level network simulator is also implemented to define the simulation environments and to represent simulation results on real mapping system. This paper also shows some features of simulation framework and simulation results.

• 제어로봇시스템학회:학술대회논문집
• /
• 1990.10a
• /
• pp.575-579
• /
• 1990

This paper describes an algorithm that can efficiently analyze the multichannel ECG signal using the frame. The input is a set of significant features (points) which have been extracted from an original sampled signal by using the split-and-merge algorithm. A signal from each channel can be hierarchical ADN/OR graph on the basis of the priori knowledge for ECG signal. The search mechanisms with some heuristics and the mixed paradigms of data-driven hypothesis formation are used as the major control mechanisms. The mutual relations among features are also considered by evaluating a score based on the relational spectrum. For recognition of morphologies corresponding to OR nodes, an hypothesis modification strategy is used. Other techniques such as instance, priority update of prototypes, and template matching facility are also used. This algorithm exactly recognized the primary points and supporting points from the multichannel ECG signals.

• Journal of the Korean Society of Food Culture
• /
• v.20 no.2
• /
• pp.261-272
• /
• 2005

The color and its coordination should intensify the customer's memory and awareness in a brand website, through the consistent communication strategy by which a variety of brand identification in the offline could be expressed efficiently. We evaluated top 5 brand-valuable family restaurants in this study, how they made the best use of the website as a new communication channel, and how they constructed the brand identification by the coloring of a website. We found out that they employed colors with a dynamic and lilting feelings matching the concept of a family restaurant. In addition, A color scheme was well designed for the specific character of a brand, though web-safe colors were seldom employed. This report can be a guide to a corporation for the color and its coordination in the website, when existing brand images need to be intensified and enhanced, or when a new brand image need to be constructed.

• Proceedings of the KIEE Conference
• /
• 1987.11a
• /
• pp.109-113
• /
• 1987

This paper briefly introduces a strategy of data links between EMS and SCADA systems for the KEPCO's EMS project. For the data links, front end/communication processors are adopted that provide for protocol conversion and communication processing in parallel with EMS/SCADA processing. The data link configuration for a communication channel is point to point links. The EMS - hardware and software - has capability of handling links utilizing both bisync protocol and X.25 (Level 1 and 2)protocol for the data link protocol.

• Proceedings of the Korea Database Society Conference
• /
• 2008.05a
• /
• pp.43-53
• /
• 2008

Various mobile Internet services have been commercialized these days and mobile banking service is considered one of the most potential business models. However, the market growth has been limited since the implementation environment is different from that of wired-internet business services. This study is investigating the effect of mobile channel preference, perceived usability, perceived value on sustained use of mobile banking service and discussed the direction of future research at the end.