• 전기학회논문지
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• 제65권9호
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• pp.1493-1496
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• 2016

This paper proposes a system for reducing the standby power consumption in using the consumer electronic devices such as a television, a home theater, a set-top box, or a DVD player. The system is consisted of a flyback converter, monitoring circuits, a relay and a micro-processor. The proposed system can reduce the standby power consumption by disconnecting the AC input and the consumer devices can be turned on with a remote control. The proposed standby power system consumes the low power to receive the infrared signal from the remote controller. Furthermore, a electronic double layer capacitor is used to store the energy with high efficiency. The proposed power system can operate the 플라이백 converter to charge the electronic double layer capacitor and connect the AC input to the consumer electronic devices. The proposed power circuit can reduce the standby power consumption in AV devices without increasing the cost. The prototype is implemented to verify the system with the commercialized products.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.87.2-87.2
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• 2015

Transparent conductors are commonly used in photoelectric devices, where the electric energy converts to light energy or vice versa. Energy consumption devices, such as LEDs, Displays, Lighting devices use the electrical energy to generate light by carrier recombination. Meanwhile, solar cell is the only device to generate electric energy from the incident photon. Most photoelectric devices require a transparent electrode to pass the light in or out from a device. Beyond the passive role, transparent conductors can be employed to form Schottky junction or heterojunction to establish a rectifying current flow. Transparent conductor-embedded heterojunction device provides significant advantages of transparent electrode formation, no need for intentional doping process, and enhanced light-reactive surface area. Herein, we present versatile applications of transparent conductors, such as NiO, ZnO, ITO in photoelectric devices of solar cells and photodetectors for high-performing UV or IR detection. Moreover, we also introduce the growth of transparent ITO nanowires by sputtering methods for large scale application.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권12호
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• pp.1194-1198
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• 2010

최근에 출시되는 모바일 단말기들은 여러 개의 무선 통신 네트워크 인터페이스를 갖는 멀티모드 형태이다. 따라서, 특정 무선 통신 인터페이스에 종속되지 않고 에너지의 소비를 줄이기 위하여 네트워크의 환경에 따라 좀 더 에너지 효율적인 네트워크 인터페이스를 선택하여 사용할 수 있다. 본 논문에서는 다수의 무선 통신 인터페이스를 갖는 휴대 장치를 위한 에너지 효율적인 네트워크 인터페이스 선택 기법을 제안한다. 제안하는 기법은 데이터 통신을 위해 폴링을 이용하여 좀 더 에너지 효율적인 네트워크 인터페이스를 선택한다. 또한, 제안하는 기법이 에너지 소비 측면에서 더욱 효율적임을 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.1-17
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• 2017

Mobile Cloud Computing has become a promising computing platform. It moves users' data to the centralized large data centers for users' mobile devices to conveniently access. Since the data storage service may not be fully trusted, many public verification algorithms are proposed to check the data integrity. However, these algorithms hardly consider the huge computational burden for the verifiers with resource-constrained mobile devices to execute the verification tasks. We propose an energy-efficient algorithm for assigning verification tasks (EEAVT) to optimize the energy consumption and assign the verification tasks by elastic and customizable ways. The algorithm prioritizes verification tasks according to the expected finish time of the verification, and assigns the number of checked blocks referring to devices' residual energy and available operation time. Theoretical analysis and experiment evaluation show that our algorithm not only shortens the verification finish time, but also decreases energy consumption, thus improving the efficiency and reliability of the verification.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권8호
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• pp.3090-3102
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• 2015

The accuracy of an augmented reality (AR) application is highly dependent on the resolution of the object's image and the device's computational processing capability. Naturally, a mobile smart device equipped with a high-resolution camera becomes the best platform for portable AR services. AR applications require significant energy consumption and very fast response time, which are big burdens to the smart device. However, there are very few ways to overcome these burdens. Computation offloading via mobile cloud computing has the potential to provide energy savings and enhance the performance of applications executed on smart devices. Therefore, in this paper, adaptive mobile computation offloading of mobile AR applications is considered in order to determine optimal offloading points that satisfy the required quality of experience (QoE) while consuming minimum energy of the smart device. AR feature extraction based on SURF algorithm is partitioned into sub-stages in order to determine the optimal AR cloud computational offloading point based on conditions of the smart device, wireless and wired networks, and AR service cloud servers. Tradeoffs in energy savings and processing time are explored also taking network congestion and server load conditions into account.

• 설비공학논문집
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• 제29권11호
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• pp.605-611
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• 2017

The purpose of this study is to calculate the energy consumption rate based on data regarding energy use in office buildings, and to confirm the general characteristics of energy consumption. The energy consumption rate of the building is calculated by dividing the energy consumption by the floor area. The energy consumption rate of small-sized office buildings was calculated as $101.48{\sim}201.55kWh/m^2{\cdot}year$ and in the case of medium-sized buildings, the range was $92.77{\sim}177.89kWh/m^2{\cdot}year$. In the case of small buildings, it was found that the energy consumption was $73.24kWh/m^2{\cdot}year$ in electronic device, $34.31kWh/m^2{\cdot}year$ in hot water supply, and $18.37kWh/m^2{\cdot}year$ in heating. In the case of medium-sized buildings, electronic devices was $73.08kWh/m^2{\cdot}year$, lighting was $18.35kWh/m^2{\cdot}year$ and heating, $15.37kWh/m^2{\cdot}year$. In all of the study buildings, the peak heating energy use was observed from 8:00 a.m. to 10:00 a.m during the winter, and the peak power management was required. Energy use at and around the midnight hour is confirmed to be 40~60% of weekly working hours, so it is necessary to manage power use at night time as well as during the day. In order to improve the accuracy of future studies, it is necessary to make efforts to secure the data with standardized energy measuring units for the various type of buildings.

• Journal of Information Processing Systems
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• 제15권3호
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• pp.593-603
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• 2019

In wearable healthcare systems, sensor devices can be deployed in places around the human body such as the stomach, back, arms, and legs. The sensors use tiny batteries, which have limited resources, and old sensor batteries must be replaced with new batteries. It is difficult to deploy sensor devices directly into the human body. Therefore, instead of replacing sensor batteries, increasing the lifetime of sensor devices is more efficient. A transmission power control (TPC) algorithm is a representative technique to increase the lifetime of sensor devices. Sensor devices using a TPC algorithm control their transmission power level (TPL) to reduce battery energy consumption. The TPC algorithm operates on a closed-loop mechanism that consists of two parts, such as sensor and sink devices. Most previous research considered only the sink part of devices in the closed-loop. If we consider both the sensor and sink parts of a closed-loop mechanism, sensor devices reduce energy consumption more than previous systems that only consider the sensor part. In this paper, we propose a new approach to consider both the sensor and sink as part of a closed-loop mechanism for efficient energy management of sensor devices. Our proposed approach judges the current channel condition based on the values of various body sensors. If the current channel is not optimal, sensor devices maintain their current TPL without communication to save the sensor's batteries. Otherwise, they find an optimal TPL. To compare performance with other TPC algorithms, we implemented a TPC algorithm and embedded it into sensor devices. Our experimental results show that our new algorithm is better than other TPC algorithms, such as linear, binary, hybrid, and ATPC.

• International Journal of Advanced Culture Technology
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• 제2권2호
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• pp.19-24
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• 2014

Many people all over the world have been conducting a great deal of research to solve the problem of global warming since the great majority consider reduction of CO2 as the only solution for that. That is why the production and conservation of energy is thought to be highly crucial. while it is important to produce energy with the high efficiency, the efficient use of the energy is also important. This paper focused on the development of devices for the reducing electricity which is a primary energy source used in homes, shops, buildings, factories and so on. Also the objective of this paper is to develop the inference mechanism as the core component of the devices. Therefore, in this paper, we propose the inference algorithm for reducing the electricity consumption using SARIMA mode and present the feasibility of the procedure.

• 한국산학기술학회논문지
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• 제14권12호
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• pp.6469-6477
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• 2013

인터넷의 규모가 확대됨에 따라, 인터넷의 에너지 소모와 GHG(Green House Gas) 배출에 대한 문제는 최근의 새로운 이슈로 등장하였다. 그러나 이러한 문제를 다루는 인터넷 그리닝(Greening)에 대한 관심은 주로 엣지(Edge) 장비에 집중되어 있으며, 과도한 네트워크 연결성으로 인한 유선 네트워크 장비의 에너지 낭비량과 절약 잠재성에 대해서는 깊이 있는 연구가 부족한 실정이다. 본 연구에서는 유선 네트워크에서 에너지 효율성에 대한 관심의 배경과 연구의 타당성을 환경적, 경제적, 에너지 사용의 측면에서 상세히 제시한다. 그리고 네크워크 장비에서의 에너지 소모량과 절약 잠재성을 추정하고 도출한 데이터를 바탕으로 유선 네트워크 장비의 에너지 소모의 주된 요인을 분석하여, 향후 미래 인터넷 기술의 발전 방향을 제시한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권6호
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• pp.2781-2798
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• 2019

Thanks to internet, as one of indispensable parts of our lives, many devices that we use in our daily lives like TV, air conditioner, refrigerator, washing machine, can be monitored and controlled remotely by becoming more intelligent via Internet of Things (IoT) technology. Smart Home applications as one of the elements of smart cities, are individually the most demanded application without question. In this study, Smart Energy Management (SEM) system, based on NodeMCU and Android, has been designed for SEM, which is a part of the smart home application. With this system, household energy consumption can be monitored in real time, as well as having the ability to record the data comprising of operation times and energy consumption information for each device. Additionally, it is ensured to meet the energy needs on a maximized level possible, during the hours when the energy costs are lower owing to the SEM system. The Android interface provides the users with the opportunity to monitor and change their electricity consumption habits in order to optimize the energy efficiency, along with the opportunity to draw up of a daily and weekly schedule.