• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권7호
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• pp.2496-2512
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• 2021

The requirements for powerful computing capability, high capacity, low latency and low energy consumption of emerging services, pose severe challenges to the fifth-generation (5G) network. As a promising paradigm, mobile edge networks can provide services in proximity to users by deploying computing components and cache at the edge, which can effectively decrease service delay. However, the coexistence of heterogeneous services and the sharing of limited resources lead to the competition between various services for multiple resources. This paper considers two typical heterogeneous services: computing services and content delivery services, in order to properly configure resources, it is crucial to develop an effective offloading and caching strategies. Considering the high energy consumption of 5G base stations, this paper considers the hybrid energy supply model of traditional power grid and green energy. Therefore, it is necessary to design a reasonable association mechanism which can allocate more service load to base stations rich in green energy to improve the utilization of green energy. This paper formed the joint optimization problem of computing offloading, caching and resource allocation for heterogeneous services with the objective of minimizing the on-grid power consumption under the constraints of limited resources and QoS guarantee. Since the joint optimization problem is a mixed integer nonlinear programming problem that is impossible to solve, this paper uses deep reinforcement learning method to learn the optimal strategy through a lot of training. Extensive simulation experiments show that compared with other schemes, the proposed scheme can allocate resources to heterogeneous service according to the green energy distribution which can effectively reduce the traditional energy consumption.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.253-254
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• 2008

본 연구는 다중 안테나 배열 시스템을 응용한 고정 중계기가 적용된 상향 링크 셀룰러 환경에서 효과적으로 외곽 사용자의 QoS(Quality of Service)를 개선시키고 보다 높은 수준의 전체 데이터 전송률을 보장하는 기술을 제안한다.

• 한국축산시설환경학회지
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• 제8권2호
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• pp.63-72
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• 2002

In Korea, a need of automatic dairy farm management system has been increased to lower production cost and to strengthen international competition. However, the present management system was mostly relied on foreign technologies and caused some problems in post management and after-sales services. Therefore, though there is a problem of price and quality at present, domestic technologies of the management system should be developed for the long run. This study was conducted to develop an electronic identification unit for an automatic dairy farm management system. The developed system was consisted of a tag, a reader, a switching circuit, and a personal computer. The tag attachable to each individual cow was developed to transmit individual radio frequency(RF) code into the air with modulation of ASK(amplitude shift keying). And the switching circuit was added to avoid confusion on reception and transmittance. The reader attached to a feeding device was developed to transmit activating signal periodically and to identify code of the individual tag when the tag was approached to the device. The reader was consisted of an active filter, a detecter, a comparator and a microcontroller. The test result was feasible enough to apply it for the automatic farm management system and the identified maximum distance was about 37cm.

• 한국전자통신학회논문지
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• 제5권4호
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• pp.406-411
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• 2010

지난 수년간 Honeynet은 공격자의 공격 도구, 공격 기법 및 공격동기를 배울 수 있는 보안 메커니즘으로서의 가치가 충분히 입증되었다. 이러한 정보는 다양한 위협에 대한 조직의 대응을 위한 핵심 정보로 활용되어 보다 효율적인 보안을 위한 기초자료가 되고 있다. 그러나 Honeynet활용의 문제점 중 하나는 구축에 많은 자원이 요구되며, 구축 및 운영관리가 어렵다는 문제이다. Honeynet 구축을 위해서는 다수의 시스템들과 다양한 보안 메커니즘을 필요로 한다. 본 논문에서는 최근 IT분야의 화두로 떠오르고 있는 가상화(Virtualization) 기술을 이용하여 기존의 Honeynet의 가치를 그대로 유지하면서도 기존 Honeynet의 자원문제, 구축 및 운영관리문제를 줄일 수 있는 Virtual Honeynet 모델을 제시하고자 한다.

• Environmental Engineering Research
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• 제24권1호
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• pp.74-81
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• 2019

Upcycling generally refers to the conversion of waste materials to something useful or valuable and is a useful concept that can be applied not only to the waste design industry but also to waste recycling and resource circulation. Our study highlights upcycling as the key concept for improving the value of waste by redefining the concept as "the recycling of waste materials and discarded products in ways that enhance their value." Four upcycling strategies are linked to material flow analyses conducted on waste electronic and electrical equipment, specifically waste refrigerators and waste computers, to examine the technologies available for implementation and suggest guidelines for the promotion of upcycling. The amount of waste refrigerators collected by the formal sector was 121,642 tons/y and the informal sector, 63,823 tons/y. The current recycling ratio of waste refrigerators was estimated as 88.53%. A total of 7,585 tons/y of waste computers were collected by the formal sector and 3,807 tons/y by the informal sector after discharge. Meanwhile, the current recycling ratio of waste computers was estimated as 77.43%. We found that it is possible to introduce 28 upcycling technologies in the case of refrigerators, and 15 technologies are available to promote upcycling in the case of computers. By refining the broad concept of upcycling and looking at the stages of material flow, our approach presents universally applicable directions for incorporating upcycling in resource recovery and recirculation plans.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.608-611
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• 2004

Grid computing environment can be used to interconnect a wide variety of geographically distributed heterogeneous computing resources based on high-speed network. To make business service, it is necessary for Grid accounting system to measure the computational cost by consuming computer resources. To collect resource consumption data, and to keep track of process without needing to recompile kernel source, we use system call wrapping. By making use of this technique, we modifies system call table and replace existing system call to new system call that can monitor processes running in CPU kernel currently. Therefore we can measure user process resource usage for Grid accounting system.

• ETRI Journal
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• 제31권1호
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• pp.89-91
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• 2009

This letter considers the problem of resource sharing among a relay and multiple user nodes in cooperative transmission networks. We formulate this problem as a sellers' market competition and use a noncooperative game to jointly consider the benefits of the relay and the users. We also develop a distributed algorithm to search the Nash equilibrium, the solution of the game. The convergence of the proposed algorithm is analyzed. Simulation results demonstrate that the proposed game can stimulate cooperative diversity among the selfish user nodes and coordinate resource allocation among the user nodes effectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권8호
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• pp.3435-3454
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• 2016

Device-to-device (D2D) communication is a potential solution to the incessant increase in data traffic on cellular networks. The greatest problem is how to control the interference between D2D users and cellular mobile users, and between D2D users themselves. This paper proposes a solution for this issue by putting the full control privilege in cellular network using the software-defined networking (SDN) concept. A software virtual switch called Open vSwitch and several components are integrated into mobile devices for data forwarding and radio resource mapping, whereas the control functions are executed in the cellular network via a SDN controller. This allows the network to assign radio resources for D2D communication directly, thus reducing interference. This solution also brings out many benefits, including resource efficiency, energy saving, topology flexibility, etc. The advantages and disadvantages of this architecture are analyzed by both a mathematical method and a simple implementation. The result shows that implementation of this solution in the next generation of cellular networks is feasible.

• 한국전자통신학회논문지
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• 제10권10호
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• pp.1157-1162
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• 2015

태양광 발전소 유지보수 기능은 센서 장치, Gateway, 유지보수 기능 플랫폼으로 구성된다. 본 논문에서는 유지보수 기능에 적합한 게이트웨이 리소스트리와 서비스 시나리오를 설계하고, 지능형 기능 모델링을 통해서 유지보수 서비스가 운영 될 수 있음을 보인다.

• 한국정보관리학회:학술대회논문집
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• 한국정보관리학회 2006년도 제13회 학술대회 논문집
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• pp.239-248
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• 2006

현대 도서관은 전자자원(electronic resource)의 양적인 급증으로 인하여, 전통적인 수서정책이나 관리시스템만으로 효과적인 관리가 점차 어려워지고 있다. 이러한 문제를 해결하기 위해 도서관들은 전자자원 관리에 대한 시스템적인 이론과 알고리즘을 개발하고 있다. 이 점에 착안하여 이 연구에서는 급증하고 있는 전자자원의 효율적 관리와 활용을 위한 필수 전자자원 관리용 메타데이터의 제안과 이를 이용한 효율적 관리방안을 제안하였다. 이 연구의 결과로 도출된 전자자원 관리용 메타데이터의 요소들은 향후 전자자원 관리시스템 개발에 있어서 기초자료로 활용될 것이다.