• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.3
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• pp.577-584
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• 2017

Long Term Evolution device-to-device (LTE D2D) is a key technology to mitigate data traffic load in a cellular system. It facilitates direct data exchange between neighboring users, which is preceded by D2D discovery. Each device advertises its presence to neighboring devices by broadcasting its discovery message. In this paper, we develop a mathematical analysis to assess the probability that discovery messages are successfully transmitted at the D2D discovery stage. We make use of stochastic geometry for modeling spatial statistics of nodes in a two dimensional space. It reflects signal to noise plus interference ratio (SINR) degradation due to resource collision and in-band emission, which leads to the discovery message reception probability being modeled as a function of the distance between the transmitter and the receiver. Numerical results verify that the newly developed analysis accurately estimates discovery message reception probabilities of nodes at the D2D discovery stage.

• Proceedings of the PSK Conference
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• 2005.04a
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• pp.67-68
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• 2005

• Journal of Information Technology Services
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• v.13 no.1
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• pp.125-134
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• 2014

Device discovery for D2D (device-to-device) communication enables a device to discover other devices in order to initiate communication with them. Devices should perform the discovery phase using a small quantity of radio resource in a short time and be able to reduce the load of the base station. Legacy device discovery schemes have focused on discovering as many target devices as possible. However, it is not appropriate for peer-to-peer D2D communication scenario. Further, synchronization problems are an important issue for discovery signal transmission. This paper proposes a discovery method that one requesting device discovers a specific target for communication. Multiple antenna beamforming is employed for the synchronization between the base station and a target device. The proposal can reduce the load of the base station using the information that it already maintains and improve the reliability of the device discovery because two times of synchronizations using beamforming among the base station and devices can make the exact discovery of a target device with mobility possible.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.8
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• pp.1521-1531
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• 2015

According to the service attributes, D2D communications establish 1-1, or 1-n channels and require the differentiated device discovery technology. This paper proposes a sector-based device discovery mechanism for 1-n D2D communication scenario in LTE-Advanced networks that a disaster happened. Our proposal is a mechanism that can extend the coverage in a disaster situation which a number of devices(survivors) need to be discovered in a short time. In the single cell environment, a larger discovery coverage can be obtained, and in the multi-cell, it is possible to mitigate the interference with adjacent links due to sector-based coverage control. Through a set of simulations, we have confirmed that our proposal has better performance in the number of devices discovered and the interference than the legacy broadcast device discover mechanism.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2256-2262
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• 2015

Recently, device-to-device (D2D) communication has been considered as key technology for future cellular system, because it can solve the problem of excessive data traffic increment and can also provide new communication services. Herein, we propose new neighbor discovery for D2D communication and examine its performance. Our proposed scheme is proximity beacon based discovery in which wireless resource for pilot transmission is assigned based on the spatial correlation of wireless channel and sensing period is adjusted according to target accuracy such that power consumption can be reduced. The performance of our propose scheme is analyzed mathematically and verified through computer simulations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1440-1442
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• 2016

As long term evolution (LTE) is the most widely deployed broadband communication technology so far, efforts are being made to develop LTE-based mission critical public safety (PS) communication systems. In this paper, we propose a device-to-device (D2D) discovery-based radio resource acquisition scheme to support the LTE D2D communication to PS systems and the realization of resource forwarding for user equipments in emergency area.

• Journal of Information Processing Systems
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• v.4 no.2
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• pp.53-60
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• 2008

The Web Services infrastructure is a distributed computing environment for service-sharing. Mechanisms for Web services Discovery proposed so far have assumed a centralized and peer-to-peer (P2P) registry. A discovery service with centralized architecture, such as UDDI, restricts the scalability of this environment, induces performance bottleneck and may result in single points of failure. A discovery service with P2P architecture enables a scalable and an efficient ubiquities web service discovery service that needs to be run in self-organized fashions. In this paper, we propose an autonomic -interleaving Registry Overlay Network (RgON) that enables web-services' providers/consumers to publish/discover services' advertisements, WSDL documents. The RgON, doubtless empowers consumers to discover web services associated with these advertisements within constant D logical hops over constant K physical hops with reasonable storage and bandwidth utilization as shown through simulation.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.3-6
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• 2001

Inflammation is an outcome or an end effect of disruption of complex immunological balance. A variety of approaches to control immunological unbalance have been tried, and some of them are in practice in the clinic. Since inflammatory disorders are reflection of very complex immunological responses, it should be difficult to have such disorders under complete control. Thus, most of the drugs, being marketed and under development, possess some degrees of undesired side offsets originating from disruption of immunological balance. Steroids are excellent drugs suppressing inflammation in short term, however, long-term use of steroids would incur a serious side effect of "rebound". Another example is TNF-${\alpha}$-neutralizing agents, such as enbrel and infliximab. TNF-${\alpha}$ has been known to play a key role in the exacerbation of inflammation, and knock-out of TNF-${\alpha}$ is regarded essential to control of chronic inflammation. The TNF-${\alpha}$-neutralizing drugs in the market are regarded very efficient in the management of rheumatoid arthritis. Upon long term use, however, those drugs cause sepsis to a certain proportion of patients. It is ironical that a high plasma level of TNF-${\alpha}$ is known to be responsible for sepsis, and that the drugs scavenging TNF-${\alpha}$ cause sepsis. The above two examples illustrate well the difficulty of discovering an anti-inflammatory drug without unwanted immunological side effects. An anti-inflammatory drug would make a case in the market, as long as the drug has huge therapeutic benefits compared to its expected but unwanted immunological side effects, where cyclooxygenase-2 inhibitors are positioning. In this presentation, will be discussed general aspects of cyclooxygenase-2 inhibition in conjunction with 3(2Η)furanone derivatives, a novel class of COX-2 inhibitors.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1650-1656
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• 2011

A series of potent tricyclic derivatives with a non-aromatic amide as potent PARP-1 inhibitors were successfully synthesized and their PARP-1 inhibitory activity was evaluated. Among the derivatives, 2-(1-propylpiperidin-4-yloxy)-7,8,9,10-tetrahydrophenanthridin-6(5H)-one 23c displayed potent activity in a PARP-1 enzymatic assay and cell-based assay ($IC_{50}$ = 0.142 ${\mu}M$, $ED_{50}$ = 0.90 ${\mu}M$) with good water solubility. Further, molecular modeling studies confirmed the obtained biological results.

• Journal of Information Technology Services
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• v.11 no.2
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• pp.185-196
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• 2012

The rapid evolution of ICT industry brings not only new services or products but also changes from common individual life to whole human society. Coping with these situations and survival, companies cannot help regarding R&D as the most important thing. So, discovering R&D projects which are suitable for the alternation is a big issue for many companies. To resolve the issue, KT has adopted Innovative Management Methodology developed by Strategos, which is co-founded by Gary Harmel. This paper describes this Innovative Management Methodology tailored to KT R&D. The methodology consists of five phases : focusing discovery, discovery, ideas/domains, domain elaboration & aiming point and R&D project proposal. Also, it shows some interim findings that came from the Innovative Management Process. Finally, the future plan for elaborating the methodology itself and generating new R&D projects is suggested.