• Title/Summary/Keyword: local energy

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Lip Contour Extraction Using Active Shape Model Based on Energy Minimization (에너지 최소화 기반 능동형태 모델을 이용한 입술 윤곽선 추출)

  • Jang, Kyung-Shik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.10
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    • pp.1891-1896
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    • 2006
  • In this paper, we propose an improved Active Shape Model for extracting lip contour. Lip deformation is modeled by a statistically deformable model based Active Shape Model. Because each point is moved independently using local profile information in Active Shape Model, many error may happen. To use a global information, we define an energy function similar to an energy function in Active Contour Model, and points are moved to positions at which the total energy is minimized. The experiments have been performed for many lip images of Tulip 1 database, and show that our method extracts lip shape than a traditional ASM more exactly.

Proactive Data Dissemination Protocol on Distributed Dynamic Sink Mobility Management in Sensor Networks (센서 네트워크에서 다수의 이동 싱크로의 에너지 효율적인 데이터 전파에 관한 연구)

  • Hwang Kwang-Il;Eom Doo-Seop;Hur Kyeong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.9B
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    • pp.792-802
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    • 2006
  • In this paper, we propose an energy-efficient proactive data dissemination protocol with relatively low delay to cope well with highly mobile sink environments in sensor networks. In order for a dissemination tree to continuously pursue a dynamic sink, we exploit two novel algorithms: forward sink advertisement and distributed fast recovery. In our protocol, the tree is shared with the other slave sinks so that we call it Dynamic Shared Tree (DST) protocol. DST can conserve considerable amount of energy despite maintaining robust connection from all sources to sinks, since tree maintenance of DST is accomplished by just distributed local exchanges. In addition, since the DST is a kindof sink-oriented tree, each source on the DST disseminates data with lower delay along the tree and it also facilitates in-network processing. Through simulations, it is shown that the presented DST is considerably energy-efficient, robust protocol with low delay compared to Directed Diffusion, TTDD, and SEAD, in highly mobile sink environment.

Offshore Wind Power, Review (해상풍력(Offshore Wind Power) 기술동향)

  • Nah, Do-Baek;Shin, Hyo-Soon;Nah, Duck-Joo
    • Journal of Energy Engineering
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    • v.20 no.2
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    • pp.143-153
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    • 2011
  • Offshore wind power(OWP) is one of the most promising renewable energy and gives higher output than onland one due to stronger and consistent wind in offshore. it offsets shortcoming of noise, spatial limit and less affects scenery, and can be built in larger size. Korea has plenty of offshore wind resources as it is surrounded by the sea in three directions. This review describes recent progress in offshore wind turbine and substructure technology. Market trend in local and overseas, Number of papers published and patents registered are analysed.

3D Shape Comparison Using Modal Strain Energy (모달 스트레인 에너지를 이용한 3차원 형상 비교)

  • 최수미
    • Journal of Korea Multimedia Society
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    • v.7 no.3
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    • pp.427-437
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    • 2004
  • Shape comparison between 3D models is essential for shape recognition, retrieval, classification, etc. In this paper, we propose a method for comparing 3D shapes, which is invariant under translation, rotation and scaling of models and is robust to non-uniformly distributed and incomplete data sets. first, a modal model is constructed from input data using vibration modes and then shape similarity is evaluated with modal strain energy. The proposed method provides global-to-local ordering of shape deformation using vibration modes ordered by frequency Thus, we evaluated similarity in terms of global properties of shape without being affected localised shape features using ordered shape representation and modal strain one energy.

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MULTISCALE MODELING OF RADIATION EFFECTS ON MATERIALS: PRESSURE VESSEL EMBRITTLEMENT

  • Kwon, Jun-Hyun;Lee, Gyeong-Geun;Shin, Chan-Sun
    • Nuclear Engineering and Technology
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    • v.41 no.1
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    • pp.11-20
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    • 2009
  • Radiation effects on materials are inherently multiscale phenomena in view of the fact that various processes spanning a broad range of time and length scales are involved. A multiscale modeling approach to embrittlement of pressure vessel steels is presented here. The approach includes an investigation of the mechanisms of defect accumulation, microstructure evolution and the corresponding effects on mechanical properties. An understanding of these phenomena is required to predict the behavior of structural materials under irradiation. We used molecular dynamics (MD) simulations at an atomic scale to study the evolution of high-energy displacement cascade reactions. The MD simulations yield quantitative information on primary damage. Using a database of displacement cascades generated by the MD simulations, we can estimate the accumulation of defects over diffusional length and time scales by applying kinetic Monte Carlo simulations. The evolution of the local microstructure under irradiation is responsible for changes in the physical and mechanical properties of materials. Mechanical property changes in irradiated materials are modeled by dislocation dynamics simulations, which simulate a collective motion of dislocations that interact with the defects. In this paper, we present a multi scale modeling methodology that describes reactor pressure vessel embrittlement in a light water reactor environment.

EVALUATION OF SURFACE HEAT FLUXES FOR DIFFERENT LAND COVER IN HEAT ISLAND EFFECT

  • Chang, Tzu-Yin;Liao, Lu-Wei;Liou, Yuei-An
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.68-71
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    • 2008
  • Our goal is to obtain a better scientific understanding how to define the nature and role of remotely sensed land surface parameters and energy fluxes in the heat island phenomena, and local and regional weather and climate. By using the MODIS visible and thermal imagery data and analyzing the surface energy flux images associated with the change of the landcover and landuse in study area, we will estimate and present how significant is the magnitude of the heat island heat effect and its relation with the surface parameters and the energy fluxes in Taiwan. To achieve our objective, we used the energy budget components such as net radiation, soil heat flux, sensible heat flux, and latent heat flux in the study area of interest derived form remotely sensed data to understand the island heat effect. The result shows that the water is the most important component to decrease the temperature, and the more the consumed net radiation to latent heat, the lower urban surface temperature.

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Eco-efficiency of Energy Symbiosis for the Energy Network of Surplus Heat

  • Shin, Choon-Hwan;Kim, Ji-Won
    • Journal of Environmental Science International
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    • v.21 no.5
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    • pp.545-553
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    • 2012
  • Eco-efficiency considers both environmental impacts and economic values. It is a useful tool for communicating with stakeholders for business decision making. This study evaluated the eco-efficiency factor (EEF) for the energy network of a dyeing company that supplies surplus heat to a neighboring apartment during the night. This symbiosis network is one of the eco-industrial park (EIP) projects in Korea and aims to benefit local residents and the industrial complex by utilizing surplus heat. In this study, two categories were annualized. The first quantified environmental burden based on $CO_2$ emissions and quantified product value in terms of steam sales. The second used a variety of environmental factors, such as fossil fuel, water and waste, to quantify environmental burden and used steam sales to quantify value. The EEF of the symbiosis network was 1.6, using the global warming impact, and determined using the multiple variable, was 1.33. This study shows that the EEF depends on variable details of environmental burden but the values of this project were very high contrast to other business or EIP project.

Measurement of Cloud Velocity and Altitude Using Lidar's Range Detection and Digital Image Correlation

  • Park, Nak-Gyu;Baik, Sung-Hoon;Park, Seung-Kyu;Kim, Dong-Lyul;Kim, Duk-Hyeon;Choi, In-Young
    • Journal of the Optical Society of Korea
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    • v.18 no.5
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    • pp.605-610
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    • 2014
  • Clouds play an important role in climate change, in the prediction of local weather, and also in aviation safety when instrument assisted flying is unavailable. Presently, various ground-based instruments used for the measurements of the cloud base height or velocity. Lidar techniques are powerful and have many applications in climate studies, including the clouds' temperature measurement, the aerosol particle properties, etc. Otherwise, it is very circumscribed in cloud velocity measurements because there is no Doppler effect if the clouds move in the perpendicular direction to the laser beam path of Doppler lidar. In this paper, we present a method for the measurement of cloud velocity using lidar's range detection and DIC (Digital Image Correlation) system to overcome the disadvantage of Doppler lidar. The lidar system acquires the distance to the cloud, and the cloud images are tracked using the developed fast correlation algorithm of DIC. We acquired the velocities of clouds using the calculated distance and DIC algorithm. The measurement values had a linear distribution.

Flow Field Design and Stack Performance Evaluation of the Thin Plate Separator for High Temperature Polymer Electrolyte Membrane Fuel Cell (고온 고분자전해질 연료전지 박판형 분리판의 유로 설계 및 스택 성능 평가)

  • KIM, JI-HONG;KIM, MINJIN;KIM, JINSOO
    • Transactions of the Korean hydrogen and new energy society
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    • v.29 no.5
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    • pp.442-449
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    • 2018
  • Research on High temperature polymer electrolyte fuel cell (HT-PEMFC) has actively been conducted all over the world. Since the HT-PEMFC can be operated at a high temperature of $120-180^{\circ}C$ using phosphoric acid-doped polybenzimidazole (PBI) electrolyte membrane, it has considerable advantages over conventional PEMFC in terms of operating conditions and system efficiency. However, If the thermal distribution is not uniform in the stack unit, degradation due to local reaction and deterioration of lifetime are difficult to prevent. The thin plate separator reduces the volume of the fuel cell stack and improves heat transfer, consequently, enhancing the cooling effect. In this paper, a large area flow field of thin plate separator for HT-PEMFC is designed and sub-stack is fabricated. We have studied stack performance evaluation under various operating conditions and it has been verified that the proposed design can achieve acceptable stack performance at a wide operating range.

Development of Hardware Simulator for Operation Analysis of DC Microgrid (DC 마이크로그리드의 동작분석을 위한 하드웨어 시뮬레이터 개발)

  • Lee, Ji-Heon;Kim, Won-Yong;Kim, Jong-Won;Han, Byung-Moon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.16 no.6
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    • pp.577-586
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    • 2011
  • This paper describes the development of hardware simulator for the operation analysis of DC microgrid. The hardware simulator consists of several distributed power sources such as a wind power generation, solar power and fuel cell, and two energy storages such as a supercapacitor and battery. The main controller which performs a role of energy management and state monitoring is connected with the local controller in each power source and storage through ethernet-based communication link. The developed hardware simulator can be utilized to analyze the performance DC microgrid with practical manner.