• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.2
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• pp.81-87
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• 2013

In this paper, we present an implementation of Long Term Evolution (LTE) Uplink (UL) system on a Software Defined Radio (SDR) platform using a conventional Personal Computer (PC), which adopts Graphic Processing Units (GPU) and Universal Software Radio Peripheral2 (USRP2) with URSP Hardware Driver (UHD) for SDR software modem and Radio Frequency (RF) transceiver, respectively. We have adopted UHD because UHD provides flexibility in the design of transceiver chain. Also, Cognitive Radio (CR) engine have been implemented by using libraries from UHD. Meanwhile, we have implemented the software modem in our system on GPU which is suitable for parallel computing due to its powerful Arithmetic and Logic Units (ALUs). From our experiment tests, we have measured the total processing time for a single frame of both transmit and receive LTE UL data to find that it takes about 5.00ms and 6.78ms for transmit and receive, respectively. It particularly means that the implemented system is capable of real-time processing of all the baseband signal processing algorithms required for LTE UL system.

• KIISE Transactions on Computing Practices
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• v.21 no.3
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• pp.215-222
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• 2015

In this paper, the Digital DoorLock by Internet of Things (DDiT) is introduced. In order to implement DDiT, an integrated micro-controller platform, Arduino is used to control an existing digital doorlock and an android type smart phone is adopted as a mobile platform. One of the advantages of DDiT is that it can be added to an existing digital doorlock and a smart phone application is used as a digital key. Owing to the smart phone application, several other types of applications could also be made. Therefore, DDiT could be used effectively and conveniently in ordinary homes as well as in high security applications such as in hotels, institutes, and companies.

• The Journal of Information Systems
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• v.23 no.1
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• pp.185-202
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• 2014

ERP, a typical enterprise application, helps companies to increase their productivity and to support their decision makings. ERP is composed of diverse functions that are optimized under PC environment, whereas the ERP applications on a mobile platform have many constraints such as a small screen, limited resolution, and computing power. Because all the functions of a ERP legacy system are not required for ERP on a mobile device, the core functions of the ERP system should be selected to increase system efficiency. In this study, two main methods were used; interviews and log analyses. The end users using a ERP system were interviewed for their perceptions, and log data analyses were made for the hitting number of specific ERP functions. The differences between the actual usage based on log data and users' cognitive preferences about ERP functions were analysed. Finally, the functional differences between users' perception and actual usage were suggested for some practical implications.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.9
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• pp.733-739
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• 2013

Recently mobile service industry has grown very rapidly. In this paper, I investigated the changes in mobile service industry as well as new direction of human life in future global society. Under these changing market conditions, competition has been also changed into global and ecological competition. But compared to the platform initiatives and ecological strategies of global companies, Korean companies' vision of building ecosystems is still unclear. New directions of mobile service industry are smart phone oriented open market, UCC, QPS and cloud computing. As such, I investigate the structure of mobile service ecosystem in order to gain strategic implications and insights in this paper.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.118-120
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• 2006

커뮤니티 컴퓨팅 시스템은 3단계 모델(CCM, CIM-PI, CIM-PS)로 이루어져 있다. 모델은 이 전의 모델을 기반으로 툴의 지원을 받아 코드를 상세화하면서 실제 구현단계에 이르게 된다. 3가지 모델 중 가장 먼저 기술해야 하는 CCM(Community Computing Model)은 커뮤니티 컴퓨팅 시스템에 대한 가장 놓은 수준의 추상화 모델로서, 시스템의 환경과 요구사항을 기술하는 부분이다. 기술된 CCM을 기반으로 생성되는 CIM-PI(Platform Independent Community Implementation Model)에서는 시스템의 구현을 고려하여 컴퓨팅 요소들과 또 이들 간에 생길 수 있는 협업관계를 자세히 기술한다. 이렇게 기술된 CIM-PI를 멀티에이전트 플랫폼 위에서 작동할 수 있도록 CDTK를 이용해 변환해 농은 것이 CIM-PS(Platform Specific Community Implementation Model)이다. 본 논문에서는 커뮤니티 컴퓨팅 시스템 개발을 더욱 쉽고 체계적으로 개발하기 위해 만든 CDTK와 이 개발 툴을 통해 얻을 수 있을 수 있었던 여러 장점들에 대해 소개한다. CDTK를 이용한 적용사례로 유비쿼터스 환경내에서 발생할 수 있는 가상시나리오에 적용하여 CDTK의 실현성과 효율성을 검증해 보았다.

• Journal of the Korea Society of Computer and Information
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• v.7 no.1
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• pp.88-93
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• 2002

In this thesis, we propose an Intelligent Agent based on CORBA technology which can exchange and share data under distributed computing environment using Agent Communication Language(ACL), Recently, due to the rapid development of network technology, the need for the database management appeared. So representative standard, CORBA have been applied and used under distributed environment. Agent applications are being developed for various fields such as electronic commerce, user interface, information retrieval. When a user searches goods, he navigates several servers on different platform until he finds desired goods. The Intelligent Agent presented in this thesis, does these tedious navigations on behalf of the user through communication between different platform.

• Journal of Platform Technology
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• v.6 no.4
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• pp.49-58
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• 2018

Complex disasters make greater damage and higher losses unexpected than the past. To prevent these disasters, it needs to prepare a plan for handling unexpected results. Especially an accident at a facility like an atomic power plant makes a big problem cause of climate change. A simulation needs to do preliminary researches based on diverse situations. In this research we define the basic component techniques to design and implement the disaster management system. Basically a hierarchical system design method is to build on the resources provided from high performance computing(HPC) and large-scale storage systems. To develop the system, it is considered middleware as well as application studies, data studies and decision making services in convergence areas.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.11
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• pp.5404-5424
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• 2018

This work is mainly focused on two major topics in cloud platforms by using OpenStack as a case study: management and provisioning of resources to meet the requirements of a service demanded by remote end-user and relocation of virtual machines (VMs) requests to offload the encumbered compute nodes. The general framework architecture contains two subsystems: 1) An orchestrator that allows to systematize provisioning and resource management in OpenStack, and 2) A resource utilization based subsystem for vibrant VM relocation in OpenStack. The suggested orchestrator provisions and manages resources by: 1) manipulating application program interfaces (APIs) delivered by the cloud supplier in order to allocate/control/manage storage and compute resources; 2) interrelating with software-defined networking (SDN) controller to acquire the details of the accessible resources, and training the variations/rules to manage the network based on the requirements of cloud service. For resource provisioning, an algorithm is suggested, which provisions resources on the basis of unused resources in a pool of VMs. A sub-system is suggested for VM relocation in a cloud computing platform. The framework decides the proposed overload recognition, VM allocation algorithms for VM relocation in clouds and VM selection.

• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.182-186
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• 2021

The market for smart phones has been booming in the past few years. There are now over 400,000 applications on the Android market. Over 10 billion Android applications have been downloaded from the Android market. Due to the Android popularity, there are now a large number of malicious vendors targeting the platform. Many honest end users are being successfully hacked on a regular basis. In this work, a cloud based reputation security model has been proposed as a solution which greatly mitigates the malicious attacks targeting the Android market. Our security solution takes advantage of the fact that each application in the android platform is assigned a unique user id (UID). Our solution stores the reputation of Android applications in an anti-malware providers' cloud (AM Cloud). The experimental results witness that the proposed model could well identify the reputation index of a given application and hence its potential of being risky or not.

• Journal of Platform Technology
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• v.9 no.1
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• pp.3-14
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• 2021

Cognitive Radio network (CR) is a promising paradigm that helps the unlicensed user (Secondary User) to analyse the spectrum and coordinate the spectrum access to support the creation of common control channel (CCC). The cooperation of secondary users and broadcasting between them is done through transmitting messages in CCC. In case, if the control channels may get jammed and it may directly degrade the network's performance and under such scenario jammers will devastate the control channels. Hopping sequences may be one of the predominant approaches and it may be used to fight against this problem to confront jammer. The jamming attack can be alleviated using one of the game modelling approach and in this proposed scheme stochastic games has been analysed with more single users to provide the flexible control channels against intrusive attacks by mentioning the states of each player, strategies ,actions and players reward. The proposed work uses a modern player action and better strategic view on game theoretic modelling is stochastic game theory has been taken in to consideration and applied to prevent the jamming attack in CR network. The selection of decision is based on Q learning approach to mitigate the jamming nodes using the optimal MDP decision process