• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1721-1735
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• 2016

Power-efficient base station (BS) operation is one of the important issues in future green cellular networks. Previously well-known BS operation schemes, the cell zooming scheme and the cell wilting and blossoming scheme, require tight cooperation between cells in cellular networks. With the previous schemes, the non-cooperative BSs of a serving cell and neighboring cells could cause coverage holes between the cells, thereby seriously degrading the quality of service as well as the power saving efficiency of the cellular networks. In this paper, we propose a novel power-efficient BS operation scheme for green downlink heterogeneous cellular networks, in which the networks virtually adjust the coverage of a serving macrocell (SM) and neighboring macrocells (NMs) without adjusting the transmission power of the BSs when the SM is lightly loaded, and the networks turn off the BS of the SM when none of active users are associated with the SM. Simulation results show that our proposed scheme significantly improves the power saving efficiency without degrading the quality of service (e.g., system throughput) of a downlink heterogeneous LTE network and outperforms the previous schemes in terms of system throughput and power saving efficiency. In particular, with the proposed scheme, macrocells are able to operate independently without the cooperation of a SM and NMs for green heterogeneous cellular networks.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.1-6
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• 2013

In this paper, we review an outline as premise for environmental analysis of green IT which has basic stage through the world in order to make knowledge map of green IT. We can analyze genuine environment for green IT based on this premise, and we expect that we can also use to analyse power of competition based on intellectual property after performing these environmental analysis.

• Journal of Communications and Networks
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• v.18 no.3
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• pp.320-326
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• 2016

In existing literature on multiple-input multiple-output (MIMO) relaying communication systems, antenna selection is often implemented by maximizing the channel capacity or the output single-to-noise ratio (SNR). In this paper, we propose an energy-efficient low-complexity antenna selection scheme for MIMO relaying communication systems. The proposed algorithm is based on beamforming and maximizing the Frobenius norm to jointly optimize the transmit power, number of active antennas, and antenna subsets at the source, relaying and destination. We maximize the energy efficiency between the link of source to relay and the link of relay to destination to obtain the maximum energy efficiency of the system, subject to the SNR constraint. Compared to existing antenna selection methods forMIMO relaying communication systems, simulation results demonstrate that the proposed method can save more power in term of energy efficiency, while having lower computational complexity.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.1-5
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• 2010

Recently emphasizing the importance of security such as national major institutions' facilities or major industrial facilities for the maintenance of security/crime prevention due to specialization of the Green Information Technology(G-IT) and Green Ubiquitous Technology(G-UT) industry fields, The Security System Building linked high technology within the government-related organization, enterprise and army the military is urgently required. This paper is about the green USN intelligent an unmanned guard MUX system that receive the signals, from alarm device within surveillance area, with various ways of communication techniques and then transmit to local control center and remote control server trough TCP/IP network. This study enables the mutual senergy effect by realizing a total solution of an unmanned guard system and also significantly contributes to the global/domestic market expansion. That can be applied to the crime prevention/security fields in the Green Ubiquitous Environment Implemented Business(survalance-Home, Gu-City, Gu-Health, etc.), and will contribute to expand companies with international competitiveness that can provide the Green Ubiquitous Vision(Gu-Vision).

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4145-4164
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• 2016

Energy harvesting is an increasingly attractive source of power for cellular networks, and can be a promising solution for green networks. In this paper, we consider a cellular network with power beacons powering multiple mobile terminals with microwave power transfer in energy beamforming. In this network, the power beacons are powered by grid and renewable energy jointly. We adopt a dual-level control architecture, in which controllers collect information for a core controller, and the core controller has a real-time global view of the network. By implementing the water filling optimized power allocation strategy, the core controller optimizes the energy allocation among mobile terminals within the same cluster. In the proposed green energy cooperation paradigm, power beacons dynamically share their renewable energy by locally injecting/drawing renewable energy into/from other power beacons via the core controller. Then, we propose a new water filling optimized green energy cooperation management strategy, which jointly exploits water filling optimized power allocation strategy and green energy cooperation in cellular networks. Finally, we validate our works by simulations and show that the proposed water filling optimized green energy cooperation management strategy can achieve about 10% gains of MT's average rate and about 20% reduction of on-grid energy consumption.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.157-166
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• 2021

This study aims to investigate the impact of green corporate identity and employees' green identification on green business performance of international automobile manufacturers in Thailand. It involves 400 employees from the target study area, using questionnaires to collect data from January to February 2021, with purposive and convenient sampling methods. Data analysis employed structural equation modeling (SEM). The results show that green corporate identity has a significant impact on employees' green personal-social identification and green business performance; meanwhile, employees' green social identification has a significant impact on green business performance. However, employees' green personal identification has a significant impact on green business performance only through employees' green social identification. Green corporate identity can increase the corporate' green business performance via economic, environmental and social aspects through employees' green personal-social identification. The findings suggest that green corporate communication through visual identity, employee behaviors, culture, policy products and services in response to environmental forces and drivers to create the green corporate identity is deemed to systematically work. Furthermore, the findings also suggest that employees' green identification on both personal and social levels can be a significant issue that the managers in automobile manufacturers should pay attention as well.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.2
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• pp.249-253
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• 2013

This study analyzed that technological competition, variety and simility of Green IT fields using patents data. To achieve this, we limited range of Green IT that reduction of energy, eco-friendly technology. Therefore we conducted analysis of patents that power saving systems, light control system, smart system, cloud computing and green house/eco systems. As the result of that, power saving field was the most developed. The simililarty of power saving and cloud computing systems are very high and similiarities of light control system, green house/eco systems and smart system were very high.

• ETRI Journal
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• v.39 no.2
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• pp.275-283
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• 2017

A green technology for reducing energy consumption has become a critical factor in ICT industries. However, for the telecommunications sector in particular, most network elements are not usually optimized for power efficiency. Here, we propose a novel energy-efficient packet switching method for use in an IP network for reducing unnecessary energy consumption. As a green networking approach, we first classify the network nodes into either header or member nodes. The member nodes then put the routing-related module at layer 3 to sleep under the assumption that the layer in the OSI model can operate independently. The entire set of network nodes is then partitioned into clusters consisting of one header node and multiple member nodes. Then, only the header node in a cluster conducts IP routing and its member nodes conduct packet switching using a specially designed identifier, a tag. To investigate the impact of the proposed scheme, we conducted a number of simulations using well-known real network topologies and achieved a more energy- efficient performance than that achieved in previous studies.

• Journal of Industrial Technology
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• v.33 no.A
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• pp.15-21
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• 2013

World governments and industries have put tremendous efforts for reduction of greenhouse gases. Specifically, IT (information technology) or ICT (information communication technology) is seen to play a pivotal role in green IT since it is deeply penetrated and related to all the industrial and business processes. The objective of this research is to enhance green maturity of a Gangwon province. We first discussed recent trends of green IT approaches/directions and prevailing green readiness indecies. Based on the environmental and industrial characteristics of Gangwon province. a future plan drawn has been examined with regard to a green IT maturity model.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1990.10a
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• pp.151-155
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• 1990