• KIEAE Journal
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• 제15권2호
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• pp.53-59
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• 2015

Purpose: Reducing energy consumption and greenhouse gas emissions is a primary concern throughout the world, and the building sector is a particularly efficient area for making these reductions. In South Korea, the government has recently enacted policies for "Green Growth" that, among other things, enforce regulations in the building certification rating system (BCRS) and reorganize existing incentive systems. Method: In this study, we examined regulations and incentive systems used in the United Kingdom, Germany, and the United States that encourage the use of energy efficient technologies in construction and compared these policies to those used in South Korea. We also disseminated surveys to experts in the fields of architecture, planning and design, and engineering to better understand their knowledge and perception of the BCRS and its incentive systems. Additionally, we sought their recommendations for improving these incentive systems. Result: Based on our comparative case studies of regulations and incentives in other countries, alongside recommendations from experts in South Korea, we concluded that incentive systems in South Korea are limited and require improvement. We make recommendations for strengthening existing regulations and incentives and for implementing new incentive programs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권7호
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• pp.3064-3094
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• 2018

Currently, the Underwater Sensor Networks (UWSNs) is mainly an interesting area due to its ability to provide a technology to gather many valuable data from underwater environment such as tsunami monitoring sensor, military tactical application, environmental monitoring and many more. However, UWSNs is suffering from limited energy, high packet loss and the use of acoustic communication. In UWSNs most of the energy consumption is used during the forwarding of packet data from the source to the destination. Therefore, many researchers are eager to design energy efficient routing protocol to minimize energy consumption in UWSNs. As the opportunistic routing (OR) is the most promising method to be used in UWSNs, this paper focuses on the existing proposed energy efficient OR protocol in UWSNs. This paper reviews the existing proposed energy efficient OR protocol, classifying them into 3 categories namely sender-side-based, receiver-side-based and hybrid. Furthermore each of the protocols is reviewed in detail, and its advantages and disadvantages are discussed. Finally, we discuss potential future work research directions in UWSNs, especially for energy efficient OR protocol design.

• 센서학회지
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• 제28권1호
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• pp.36-40
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• 2019

Energy harvesting is an advantageous technology for wireless sensor networks (WSNs) that dispenses with the need for periodic replacement of batteries. WSNs are composed of numerous sensors for the collection of data and communication; hence, they are important in the Internet of Things (IoT). However, due to low power generation and energy conversion efficiency, harvesting technologies have so far been utilized in limited applications. In this study, a piezoelectric energy harvester was modeled in a vibration environment. This harvester has an oval-shaped configuration as compared to the conventional cantilever-type piezoelectric energy harvester. An analytical model based on an equivalent circuit was developed to appraise the advantages of the oval-shaped piezoelectric energy harvester in which several structural parameters were optimized for higher output performance in given vibration environments. As a result, an oval-shaped energy harvester with an average output power of 2.58 mW at 0.5 g and 60 Hz vibration conditions was developed. These technical approaches provided an opportunity to appreciate the significance of autonomous sensor networks.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제3권5호
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• pp.151-154
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• 2014

모바일 기기에서 어플리케이션의 에너지 소비는 운영체제, 실행시간 환경, 컴파일러, 어플리케이션 등이 복잡한 상호 작용을 통해 이루어진다. 최근까지 에너지-지향적인 고수준 및 저수준의 컴파일러 기술을 적용하여 모바일 기기에서 어플리케이션의 에너지 소비를 줄이기 위한 노력이 진행되고 있다. 본 논문에서는 안드로이드 달빅에서 실행되는 dex 파일로부터 달빅 바이트코드를 추출한 후 에너지 소비 최적화를 위한 리스트 인스트럭션 스케줄링을 적용하여 어플리케이션의 에너지 소비를 줄이고자 한다. 이러한 연구는 급속도로 확산되고 있는 안드로이드 기반 어플리케이션이 전력 공급이 제한적인 모바일 환경에서 최적화된 전력 에너지 소비할 수 있는 환경을 구축하는 데 활용할 수 있다.

• Journal of Advanced Marine Engineering and Technology
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• 제29권8호
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• pp.883-890
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• 2005

The industrial growth and the raised living quality have led to the massive energy consumption. As a result. the polluted environment and the limited amount of energy resources emerged as serious problems to be resolved in 21st century. Especially, in the case of Korea whose imported energy dependency rate is 98.2$\%$ in 2003 and constantly increasing every rear. more than 24$\%$ of overall energy consumption is for housing and commercial use. In order to cope with the shortage of natural energy resources, it is inevitable to develop alternative sustainable energy resources including seawater heat. so that they can replace existing resources. The heat transfer air velocity 3.5 m/s is proper to consideration with the body the pipe size 200A is more suitable than look due to the air velocity quantify and the ratio of pipe surface area. And the error between experimental data with simulation is below 5.34$\%$ so the suggested equation for calculating heat transfer capacity can be used. Therefore out of many methods utilizing seawater heat. this work Presents the efficiency of using sea water heat as a resource for air-conditioners which can be converted from the outside air through the air-to-heat conversion tube . Consequently. this method provides pretty reasonable energy efficiency.

• KIEAE Journal
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• 제16권6호
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• pp.5-12
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• 2016

Purpose: Quasi-steady state simulations have played a pivoting role to expand the user group of simulation to design engineers and architects in Korea. Initially they are introduced in the market as a building energy performance rating tool. In domestic practice, however, quasi-steady state simulations seem to be regarded as a de facto simulation only available for energy retrofit. Selection of ECMs and economic feasibility analysis are being decided through these tools, which implies that running these tools has become a norm step of the Investment-grade Audit. Method: This study aims at identifying issues and problems with the current practice via test cases, analyzing the reasons and opportunities, and then eventually suggesting proper uses of quasi-steady state and dynamic simulations. Result: The functionality of quasi-steady state simulations is more optimized to the rating. If they are to used for energy retrofits, their off-the-shelf functions also need to be expanded for customization and detailed reports. Yet their roles may be limited only to the go/no go decision; because their algorithms are still weak at precisely estimating energy and load savings that are required for making investment decisions compared to detailed simulations.

• Ocean Systems Engineering
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• 제9권4호
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• pp.391-407
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• 2019

Tracking the location (position) of a surface or underwater marine vehicle is important as part of guidance and navigation. While the Global Positioning System (GPS) works well in an open sea environment but its use is limited whenever testing scaled-down models of such vehicles in the laboratory environment. This paper presents the design, development and implementation of a low energy ultrasonic augmented single beacon-based localization technique suitable for such requirements. The strategy consists of applying Extended Kalman Filter (EKF) to achieve location tracking from basic dynamic distance measurements of the moving model from a fixed beacon, while on-board motion sensor measures heading angle and velocity. Iterative application of the Extended Kalman Filter yields x and y co-ordinate positions of the moving model. Tests performed on a free-running ship model in a wave basin facility of dimension 30 m by 30 m by 3 m water depth validate the proposed model. The test results show quick convergence with an error of few centimeters in the estimated position of the ship model. The proposed technique has application in the real field scenario by replacing the ultrasonic sensor with industrial grade long range acoustic modem. As compared with the existing systems such as LBL, SBL, USBL and others localization techniques, the proposed technique can save deployment cost and also cut the cost on number of acoustic modems involved.

• 한국가스학회지
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• 제4권4호
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• pp.13-19
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• 2000

지구환경 보존 및 화석연료의 고갈에 대한 대책으로 미활용 에너지원에 대한 연구들이 진행되고 있다. 본 연구는 이러한 관점에서 지하철에서 배기되는 공기를 공기열원 히트펌프의 열원으로 이용할 수 있는가를 알아보기 위해 서울 지하철 5호선 Y역을 대상역으로 선정하여 터널내의 공기온도, 배열량을 시뮬레이션하였다. 이 배열량을 난방용 열원으로 히트펌프에 이용했을 경우 전력소비량과 대기를 직접 이용하는 히트펌프의 전력소비량을 계산하여 에너지 절약량을 검토하였으며, 여름철 냉방 유무 및 환기시간에 따른 터널내 온열환경을 파악하였다.

• KIEAE Journal
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• 제7권6호
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• pp.23-28
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• 2007

Limited fossil fuels and unstable energy supply are considered as one of the critical problems in architecture requiring large amounts of energy. In order to this challenge, environment-friendly architecture design is required. Clear data should be prepared to apply solar energy to architecture aggressively and properly. This study used FS statistical analysis data regarding average daily solar radiation of Seoul observed over 20 years to find out standard year and standard daily solar radiation. This study also aims to compare and evaluate an appropriate method of selecting a standard year which is too close to measurement value through comparison and analysis with daily solar radiation acquired by applying overseas researchers' suggesting weight factor. As a result, the data nearest to measurement value of daily solar radiation was UK CIBSE TRY(TYPE 2) displaying 0.100in t-statistic index. For UK CIBSE TRY(TYPE 2), weight factor was applied to three climatic elements except relative humidity. TYPE 1 and TYPE 3 recorded 0.343 and 0.367, respectively, showing higher record of t-statistic than TYPE 2. TYPE 1 was calculated through FS statistical value of single data about daily solar radiation with other climatic elements excluded. For TYPE 3, relative humidity was added to TYPE 2. In particular, since TYPE 2 was closer to the measurement value compared to the others, it is necessary to consider relationship with other climate elements if other climate elements are added.

• Journal of Information Technology Applications and Management
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• 제12권4호
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• pp.13-24
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• 2005

The sensor network is a key component of the ubiquitous computing system which is expected to be widely utilized in logistics control, environment/disaster control, medical/health-care services, digital home and other applications. Nodes in the sensor network are small-sized and exposed to adverse environments. They are demanded to perform their missions with very limited power supply only. Also the sensor network is composed of much more nodes than the wireless ad hoc networks are. In case that some nodes consume up their power capacity, the network topology should change, and rerouting/retransmission is necessitated. Communication protocols studied for conventional wireless networks or ad hoc networks are not suited for the sensor network resultantly. Schemes should be devised to control the efficient usage of node power in the sensor network. This paper proposes a medium access protocol to enhance the efficiency of energy consumption in the sensor network node. Its performance is analyzed by simulation.