• 한국정보전자통신기술학회논문지
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• 제14권1호
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• pp.14-21
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• 2021

그린 네트워킹(Green networking)은 유선 데이터 네트워크(Wired data network)에서 통합적인 에너지 관리를 통해 에너지 낭비와 CO2 배출 감소를 유도하기 위해 주요 관심분야가 되었다. 그러나 액세스 네트워크(access networks)는 유선 데이터 네트워크 영역에서 사용자 단말을 제외하면 가장 많은 에너지를 소비하는 영역임에도 불구하고 그 범위가 매우 광대하여 통합적인 관리가 어렵고, 그 에너지 소모량과 에너지 절약 잠재성을 예측하기가 매우 어렵다. 본 논문에서는 기존의 다양한 수학적 예측 모델과 실험 및 실측 데이터를 이용하여 유선 액세스 네트워크의 에너지 소모량 데이터를 수집하고 머신러닝(Machine learning)의 지도학습을 이용한 다중 선형 회귀모델을 생성한다. 또한 생성한 모델로부터 다양한 실험을 통해 회귀모델의 성능을 최적화하여 유선 액세스 네트워크의 에너지 소모량을 예측하였고 생성한 회귀모델은 널리 알려진 평가 지표를 통해 성능을 평가하였다.

• Journal of Communications and Networks
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• 제18권4호
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• pp.600-609
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• 2016

In this paper, we propose a two-stage base station (BS) sleeping scheme to save energy consumption in cellular networks. The BS sleeping mode is divided into a light sleeping stage and a deep sleeping stage according to whether there is a user in the BS's coverage. In the light sleeping stage, a BS will retain its coverage and frequently switch between the on state and the doze state according to the service characteristics. While in the deep sleeping stage analysis, the BS will shut down its coverage, and neighbor BSs will patch the coverage hole. Several closed-form formulas are derived to demonstrate the power consumption in each sleeping stage and the stage switching conditions are discussed to minimize the average power consumption. The average traffic delay caused by BS sleeping and the average deep sleeping rate under a given traffic load have also been studied. In addition, it is shown that BS sleeping is not always possible because of the limited quality of service (QoS) requirements. Simulation results show that the proposed scheme can effectively reduce the average BS power consumption, at the cost of some extra traffic delay. In summary, our proposed framework provides an essential understanding of the design of future green networks that aim to take full advantage of different stages of BS sleeping to obtain the best energy efficiency.

• 대한전자공학회논문지TC
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• 제47권10호
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• pp.27-35
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• 2010

무선 패킷 망에서 무선 자원과 무선 단말의 전력을 얼마나 효율적으로 사용할 수 있는가 하는 것은 무선 패킷 망 보급을 위한 기본 해결 과제이다. 이에 단말의 전력 소모를 줄이면서 무선 망 용량 (capacity)을 증가시키는 기법으로 전송 파워 조절 기법이 주목받고 있다. 무선 패킷 망에 전송 파워 조절 기법을 적용할 때 전송 파워의 세기에 따라 공평한 전송성능을 보장하지 못하고 기아상태에 이르는 전송 불공평성 문제가 지금까지 깊이 연구되지 않고 있다. 이에 본 연구에서는 전송 파워의 세기에 따른 성능 불공평성을 경쟁자 수의 차이에 의한 불공평한 매체 접근 기회에 있음을 분석을 통해 보이고 불공평성을 해결하기 위한 간단한 물리-맥 (PHY-MAC) 계층 간 접근법을 제안한다.

• 한국인터넷방송통신학회논문지
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• 제12권3호
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• pp.123-131
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• 2012

오래 전부터 연료의 가격은 상승하고 있다. 제조업체는 보증을 통해 실용적인 대안을 찾고자 전기와 강력한 바이오 연료를 이용하여 차량의 성장가능을 연구하고 있다. 이제, 이러한 녹색 환경(emission) 관련된 보증은 보증기간이 확장되며, 이러한 보증을 "수퍼 보증" 이라 불린다. 본 논문의 주요 결과는 라돈 변환의 역행렬을 보증공간의 수치를 줄이기 위해 사용되며, 응용 프로그램 및 RBF 네트워크를 사용하여 대략적인 이변량의 보증 기능에 새로운 방법을 제시한다. 이 방법은 다음과 같은 단계로 구성되어 있다. 첫째, 라돈 변환을 이용하여, 이변량 보증 함수의 1차원 함수를 줄일 수 있다. 둘째, 1 차원 함수의 각 신경 서브 네트워크와 신경 네트워크 기법을 사용하여 근사할 수 있다. 셋째, 이러한 신경 sub-networks 형태로 최종 근사 신경망 함께 결합 된다. 넷째, 라 돈 변환의 역함수 값을 사용 하여 최종 근사 신경 네트워크에 우리가 주어진 함수 근사화를 얻을 수 있다. 또한, 우리는 자동차 회사의 일부 그린 보증 데이터를 가지고 위의 방법을 적용한다.

• 한국유기농업학회지
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• 제15권2호
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• pp.171-183
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• 2007

Green tourism is a stay-flow activity between people in urban and rural area, using a natural view, tradition, and life in agricultural area. And green tourism provides rest, recreation, and new experience fur people living in urban area as well as opportunities to increase income for people in rural area. In recently, amenity is rapidly rising as a main factor fur a regional competitiveness. Boseong county shows a typical agriculture industrial structure with a weak independent base, but has a beautiful tea fields in full seasons. Boseong county is making an effort to activate the regional economy, but the result fall short of one's expectation. Several methods to activate the green tourism of Boseong county are as follows: i) introduction of specialized theme relating Boseong green tea; ii) provision of information regarding tourist resort and development of experience-program related to green tea business; iii) establishment of a sales network of products through accommodations in private houses; iv) establishment of networks among regions to achieve systematic sales of tourist experience, accommodations in private houses, and local speciality simultaneously.

• 기술사
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• 제42권2호
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• pp.41-48
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• 2009

The Government declared 'Low-Carbon Green Growth' as the new national vision for future development to improve economic growth and quality of life through higher energy efficiency, less energy consumption, wider use of renewable energy, etc. Korea can no longer delay participating in international efforts against global warming by reducing carbon dioxide and other greenhouse gas emissions. Thus low-carbon green growth is not a matter of choice, and it becomes indispensible to sustaining the nation's economic development. The Government is determined to take the initiative in speeding up economic recovery by carrying out the large scale investment projects such as the Korean version of a 'Green New Deal. The 49 trillion-won projects include river improvement, eco-friendly transportation networks, advanced information infrastructure, water resources & dam construction, green cars & clean energy development, etc. which will create nearly one million new jobs over the next four years.

• 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.

• 한국주조공학회지
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• 제34권3호
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• pp.107-111
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• 2014

Permeability is the ability of a material to transmit fluid/gases. It is an important material property and it depends on mould parameters such as grain fineness number, clay, moisture, mulling time, and hardness. Modeling the relationships among these variable and interactions by mathematical models is complex. Hence a biologically inspired artificial neural-network technique with a back-propagation-learning algorithm was developed to estimate the permeability of green sand. The developed model was used to perform a sensitivity analysis to estimate permeability. The individual as well as the combined influence of mould parameters on permeability were simulated. The model was able to describe the complex relationships in the system. The optimum process window for maximum permeability was obtained as 8.75-10.5% clay and 3.9-9.5% moisture. The developed model is very useful in understanding various interactions between inputs and their effects on permeability.

• 한국통신학회논문지
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• 제35권1B호
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• pp.125-135
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• 2010

최근 지구 온난화가 가속화됨에 따라 고도화된 IT를 활용하여 환경을 보전하고자 RFID/USN을 활용한 Green IT에 관심이 집중되고 있다. 본 논문에서는 지하주차장과 같은 공동시설에서 불필요하게 낭비되는 전기에너지를 줄이고자 유비쿼터스 센서 네트워크 기반 지하주차장 조명제어시스템을 구현하였다. 지하주차장 조명제어시스템은 차량의 진출입을 감지하기 위한 교차로노드와 조명등을 제어하기 위한 조명노드로 구성된다. 지하주차장과 같은 특수한 환경에 적합한 계층적 클러스터 기반 라우팅 프로토콜, 계층적 주소할당 기법, 확률적 필터링 기법을 개발하여 적용하였다. 지하주차장 조명제어시스템을 구현하여 전기에너지 절감율을 실험한 결과 약 61.7% 절감됨을 확인할 수 있었다.

• Journal of Communications and Networks
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• 제12권2호
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• pp.114-121
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• 2010

In this paper, an auctioning strategy is proposed for cellular networks that ensures net energy savings. The pricing scheme, in conjunction with a two dimensional bid structure, incentivizes cooperation at the terminal nodes for better interference management at receivers and for cooperative relaying. It is shown that, for the proposed auctioning strategy, network operators are guaranteed revenue gains, mobile nodes' dominant strategy is to bid their true valuation of their energy resources, and overall effective energy gains occur under the assumption of a reserve price for bidding. Simulation results show that significant energy savings can be achieved by employing this auctioning mechanism for a 3G cellular set-up.