• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.6A
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• pp.565-572
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• 2007

3G Long Term Evolution (3G LTE) is a next generation cellular networks system capable or providing various mobile multimedia services by using OFDMA and MIMO based radio access technology. Among many differences from existing WCDMA based systems, the facts that 3G LTE uses Physical Resource Block (PRB) as its radio resources and provides all services through the PS domain make the development of new resource management schemes necessary. This paper proposes an adaptive partitioning based downlink call admission control scheme. It separates realtime call requests from non-realtime ones, specifies maximum allowable resource amounts for each type, but if the maximum is exceeded, call requests are accepted with probability proportional to remaining resource amounts. Despite the fact that such adaptive concept has been already adopted by other call admission schemes, the contributions of our paper, which are that we are able to find an efficient way to apply the proposed scheme exploiting PRB characteristics and measure the resource usage of base stations by PRB utilization and payload ratio, are still valid. When judging from simulation results in comparison with others, our scheme is able to prioritize realtime call requests over non-realtime ones, and at the same time, overall system performance is superior.

• Convergence Security Journal
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• v.8 no.2
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• pp.79-85
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• 2008

Our paper deals with a method for supporting multiple call/sessions in a mobile terminal. The different identifier for each protocol layer is assigned to each session when a mobile terminal sets SDP for multimedia services. In particular, QoS based tasks are used for managing the traffics in radio interface. Also, queuing, admission control, load control, resource allocation and scheduling are done based on the priority of sessions. The various multimedia services which is different in the requirement of resource allocation are able to be serviced simultaneously because a mobile terminal can provide the various services based on this scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3B
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• pp.325-338
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• 2004

As the recent rapid development of internet technology and the wide spread of multimedia communication, massive increase of network traffic causes some problems such as the lack of network paths and the bad quality of service. To resolve these problems, this paper presents a traffic control agent that can perform the dynamic resource allocation by controlling traffic flows on a DiffServ network. In addition, this paper presents a router that can support DiffServ on Linux to support selective QoS in IP network environment. To implement a method for selective traffic transmission based on priority on a DiffServ router, this paper changes the queuing discipline in Linux, and presents the traffic control agent so that it can efficiently control routers, efficiently allocates network resources according to service requests, and relocate resources in response to state changes of the network. Particularly for the efficient processing of Assured Forwarding(AF) Per Hop Behavior(PHB), this paper proposes an ACWF$^2$Q$^{+}$ packet scheduler on a DiffServ router to enhance the throughput of packet transmission and the fairness of traffic services.s.

• Journal of Korea Multimedia Society
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• v.14 no.1
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• pp.144-152
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• 2011

As IPv4 addresses are exhausting, the use of IPv6 addresses is increasing. IPv6 environment provides address auto-configuration function. If addresses are allocated to each host automatically, network management system has difficulty in inspecting every IP of all devices and keeping the relevant informations. Also, as IP addresses are configured automatically, problems such as malicious users accessing network devices with no restriction can occur. To solve these problems, managing and blocking of malicious user is necessary. In this paper, we suggest agent system for searching of host computer and blocking network access which manages and protects the major network resources efficiently by searching host and blocking unauthorized host access to network in IPv6 environment. According to the test results of function of this agent system in IPv6 environment, we have checked that this system performs searching and blocking function normally.

• Journal of Korea Multimedia Society
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• v.13 no.8
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• pp.1163-1170
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• 2010

In this paper, in order to develop a remote progress management system through the Internet, we show a design method to make easy maintenance by developing the system with both the JAVA language and GoF Design Patterns. For the system implementation, we added the RS232C and RS422/RS485 communication modules to PLC(Programmable Logic Controller) in the control box which provide the real time status data of machines. Also we set up the RS232C to Ethernet converter based on wireless environment to communicate the PLC control data. We use JAVA Swing components to implement the multi-tier architecture system supported the GUI of the Applet and Frame at the same time so that the manager grasps the progress of work easily at the remote machines through the Internet. The key objective of the multi-tier architecture is to share resources among clients, this proposed system can help to develop the software to control the remote machine, and also it has the advantage that developer who wants to make a similar software can make easy to add new function reusing the existing codes.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.3
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• pp.413-422
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• 2016

A construction manager tries to complete a construction project within its duration and budget using available resources. Schedule networks such as Bar-chart and CPM(critical path method) are used to finish the project within the duration. A survey shows that small contractors prefer Microsoft Excel to commercial time management softwares to manage construction time in their fields, because the Excel is useful to control cost with schedule and few time management experts works in the small contractors. A college produces talented graduates who are able to manage time of a construction project. But the quality and quantity of college eduction for time management is insufficient. Another survey shows that majors in Architectural engineering of local national universities have the curriculum for time management, and teach mainly the theory of network scheduling and how to make the network schedule. The several majors have classes for the theory and exercise of commercial time management softwares in several majors. It is necessary to educate time management experts able to use Bar-chart and commercial time management softwares for the small contractors.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.377-382
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• 2021

In order to advance forest resource management, it is necessary to solve problems such as the aging of forest-related industry workers and the field investigation system centered on manpower. Therefore, in this study, the trend of establishment and utilization of overseas forest geospatial information applied with the latest technology for scientific forest resource management was investigated to identify the domestic application plan. Overseas, photogrammetry and LiDAR technologies were being used to construct and utilize forest geospatial information. In the case of photogrammetry, it was used to measure the volume of vegetation, diameter, and tree height. And LiDAR technology has been applied to the measurement of diameter, and tree height. Through the analysis of overseas cases, it was identified how to construct forest geospatial information using photogrammetry and LiDAR, and it was found that LiDAR showed higher accuracy than photogrammetry. In the future, if the construction of forest geospatial information using various LiDAR sensors are performed and the accuracy and work efficiency are analyzed, it will be possible to present the possibility of using new technologies in the construction of forest geospatial information in Korea.

• The KIPS Transactions:PartD
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• v.13D no.5 s.108
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• pp.741-748
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• 2006

This paper describes the system which provides home entertainment services to users using the middleware-cooperation module which makes UPnP and ACAP cooperate with each other. UPnP or ACAP providespowerful functionalities to its own network to play multimedia contents using its own resources. U one middleware uses the information and the resources of another middleware, itcould provide services with more contents and more powerful functionalities than those which it originally provides. This paper develops the middleware-cooperation module to make two middleware cooperate with each other and use resources of another middleware. The middleware-cooperation module makes UPnP and ACAP cooperate with each other, and it makes them share their information and resources without resource collision.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.850-857
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• 2013

The objective of this paper is to provide service continuity based on an efficient subchannel allocation in OFDMA systems. The resource management for handover are necessary to maintain the QoS requirements of different multimedia applications because the service continuity may be defected by some delay and information loss. Therefore we propose two subchannel management schemes applied to OFDMA systems. Firstly, a superposition allocation of interference subchannels is achieved by modifying a frequency reuse scheme, using co-subchannel interference principle. Secondly for handover applications, we suggest a novel subchannel reservation scheme to adjust the number of allocated channels, depending on the different characteristics and diverse quality of mobile multimedia applications. Simulation results show that the total throughput for the proposed method is increased up to 20% at average and peak arrivals and the handover failure rate is decreased to about 25%, as compared to the conventional method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.298-301
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• 2009

최근 들어 무선 멀티미디어 서비스를 위한 Wireless Sensor Network 에 관한 연구가 활발히 진행됨에 따라 그 응용의 한 부분으로써 이미지 센서를 이용하여 이미지 데이터를 전송하는 WISN(Wireless Image Sensor Networks) 에 관한 연구가 시작되었다. WISN은 센서노드의 제한된 자원(배터리, 대역폭, 처리속도, 메모리 크기)으로 인해 많은 어려움을 갖는다. 특히 그 중에서 제한된 배터리로 인해 이미지 센서노드는 효율적인 에너지 관리가 필요하다. 이미지 센서노드의 에너지 소모는 이미지 캡쳐 과정, 이미지 데이터의 처리 및 가공(compression)과정, 이미지 데이터의 전송 과정에서 발생한다. 또한 수 Kbyte 이미지 데이터는 기존의 무선센서 네트워크의 데이터보다 훨씬 크기 때문에 빈번한 이미지 데이터의 전송은 노드의 수명을 단축시켜 전체 네트워크의 분단을 초래한다. 본 논문에서는 이러한 문제점을 해결하기 위해 JPEG 이미지 크기의 변화량을 고려하여 전송 횟 수를 최소화하는 기법을 제안한다. 종단 센서노드는 자신이 이전 JPEG이미지와 현재 JPEG이미지의 크기를 비교하여 특정 임계값 이하이면 전송하지 않고, 임계값 이상일 때에는 변화된 특정 부분의 이미지만을 보냄으로써 데이터량을 줄이게 된다. 결과적으로 효율적 에너지 관리를 통해 센서 노드의 라이프타임을 향상 시키는 결과를 가진다. 제안된 기법을 검증하기 위하여 테스트 보드를 만들어 제안된 기법과 일반적인 방법에서의 데이터의 전송 횟수 및 에너지 소모량과 노드의 라이프타임을 비교하여 제안된 기법의 성능의 우수함을 보였다.