• Title/Summary/Keyword: energy estimates

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The Method to Calculate the Walking Energy-Weight in ERAM Model to Analyze the 3D Vertical and Horizontal Spaces in a Building (3차원 수직·수평 건축공간분석을 위한 ERAM모델의 보행에너지 가중치 산정 연구)

  • Choi, Sung-Pil;Choi, Jae-Pil
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.6
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    • pp.3-14
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    • 2018
  • The aim of this study is to propose a method for calculating the weight of walking energy in ERAM model by calculating it for the analysis of vertical and horizontal spaces in a building. Conventional theories on the space analysis in the field of architectural planning predict the pedestrian volume of network spaces in urban street or in two-dimensional plane within a building, however, for vertical and horizontal spaces in a building, estimates of the pedestrian volume by those theories are limited. Because in the spatial syntax and ERAM model have been applied weights such as the spatial depth, adjacent angles, and physical distances available only to the two-dimensional same layer or plane. Therefore, the following basic assumptions and analysis conditions in this study were established for deriving a predictor of pedestrian volume in vertical and horizontal spaces of a building. The basic premise of space analysis is not to address the relationship between the pedestrian volume and the spatial structure itself but to the properties of spatial structure connection that human beings experience. The analysis conditions in three-dimensional spaces are as follows : 1) Measurement units should be standardized on the same scale, and 2) The connection characteristics between spaces should influence the accessibility of human beings. In this regard, a factor of walking energy has the attributes to analyze the connection of vertical and horizontal spaces and satisfies the analysis conditions presented in this study. This study has two implications. First, this study has shown how to quantitatively calculate the walking energy after a factor of walking energy was derived to predict the pedestrian volume in vertical and horizontal spaces. Second, the method of calculating the walking energy can be applied to the weights of the ERAM model, which provided the theoretical basis for future studies to predict the pedestrian volume of vertical and horizontal spaces in a building.

Determination of taxiing resistances for transport category airplane tractive propulsion

  • Daidzic, Nihad E.
    • Advances in aircraft and spacecraft science
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    • v.4 no.6
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    • pp.651-677
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    • 2017
  • For the past ten years' efforts have been made to introduce environmentally-friendly "green" electric-taxi and maneuvering airplane systems. The stated purpose of e-taxi systems is to reduce the taxiing fuel expenses, expedite pushback procedures, reduce gate congestion, reduce ground crew involvement, and reduce noise and air pollution levels at large airports. Airplane-based autonomous traction electric motors receive power from airplane's APU(s) possibly supplemented by onboard batteries. Using additional battery energy storages ads significant inert weight. Systems utilizing nose-gear traction alone are often traction-limited posing serious dispatch problems that could disrupt airport operations. Existing APU capacities are insufficient to deliver power for tractive taxiing while also providing for power off-takes. In order to perform comparative and objective analysis of taxi tractive requirements a "standard" taxiing cycle has been proposed. An analysis of reasonably expected tractive resistances has to account for steepest taxiway and runway slopes, taxiing into strong headwind, minimum required coasting speeds, and minimum acceptable acceleration requirements due to runway incursions issues. A mathematical model of tractive resistances was developed and was tested using six different production airplanes all at the maximum taxi/ramp weights. The model estimates the tractive force, energy, average and peak power requirements. It has been estimated that required maximum net tractive force should be 10% to 15% of the taxi weight for safe and expeditious airport movements. Hence, airplanes can be dispatched to move independently if the operational tractive taxi coefficient is 0.1 or higher.

In-line Smart Oil Sensor for Machine Condition Monitoring (기계 상태진단을 위한 인-라인형 오일 모니터링 스마트 센서)

  • Kong, H.;Ossia, C.V.;Han, H.G.;Markova, L.
    • Tribology and Lubricants
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    • v.24 no.3
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    • pp.111-121
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    • 2008
  • An integrated in-line oil monitoring detector assigned for continuous in situ monitoring multiple parameters of oil performance for predicting economically optimal oil change intervals and equipment condition control is presented in this study. The detector estimates oil deterioration based on the information about chemical degradation, total contamination, water content of oil and oil temperature. The oil oxidation is estimated by "chromatic ratio", total contamination is measured by the changes in optical intensity of oil in three optical wavebands ("Red", "Green" and "Blue") and water content is evaluated as Relative Saturation of oil by water. The detector is able to monitor oils with low light absorption (hydraulic, transformer, turbine, compressor and etc. oils) as well as oils with rather high light absorption in visible waveband (diesel and etc. oils). In a case study that the detector is applied to a diesel engine oil, it is found that the detector provides good results on oil chemical degradation as well as soot concentration.

Preliminary cost estimation for large-scale nuclear hydrogen production based on SI process (초고온가스원자로 열원 SI 공정을 이용한 원자력수소생산시스템 비용 예비 분석)

  • Yang, Kyoung-Jin;Choi, Jae-Hyuk;Lee, Ki-Young;Lee, Tae-Hoon;Lee, Kyoung-Woo;Kim, Mann-Eung
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.723-726
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    • 2009
  • As a preliminary study of cost estimates for nuclear hydrogen systems, the hydrogen production costs of the nuclear energy sources benchmarking GT-MHR are estimated in the necessary input data on a Korean specific basis. G4-ECONS developed by EMWG of GIF in 2008 was appropriately modified to calculate the cost for hydrogen production of SI process with VHTR as a thermal energy source rather than the LUEC. The estimated costs presented in this paper show that hydrogen production by the VHTR could be competitive with current techniques of hydrogen production from fossil fuels if $CO_2$ capture and sequestration is required. Nuclear production of hydrogen would allow large-scale production of hydrogen at economic prices while avoiding the release of $CO_2$. Nuclear production of hydrogen could thus become the enabling technology for the hydrogen economy. The major factors that would affect the cost of hydrogen were also discussed.

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Estimation of In vitro Digestibility of Barley Straw by Using a Homogenized Rumen Fluid and Artificial Saliva Mixed with Nitrogen and Energy Sources

  • Chaudhry, Abdul S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.11 no.1
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    • pp.13-16
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    • 1998
  • A $2{\times}2{\times}4$ factorial study was conducted to examine the possibility of improving estimates of in vitro digestibility, using untreated (UBS) and ammonia-treated (ABS) barley straw, through homogenization of rumen fluid (RF) and by additions of urea (U) and casein (C) as N sources and Xylose + Glucose (XG) as energy sources into artificial saliva. Digestibiltiy of ABS was significantly greater than that of UBS (p < 0.001). There was a significant decrease in digestibility when additions (U, UC, UCXG) were compared with the control (p < 0.001). A 2-way interaction between RF and straw type was significant (p < 0.05) for dry matter digestibility (DMD). Homogenization of RF increased DMD of ABS (p < 0.05) whereas it decreased DMD of UBS (p > 0.05). The study showed that addition of N alone or in combination with energy sources was not better than control, rather the reverse, digestion was inhibited by a combination of U and casein (UC). It was concluded that sufficient N and branched chain fatty acids were supplied in the inoculum from sheep fed high protein grass cubes to support the growth of cellulolytic microbes during in vitro incubation. Further studies are, however, required to explore the potential of homogenization in improving the in vitro method to estimate digestibility of cereal straws.

Evaluation of Seismic Performance on Shear Walls in Steel House (스틸하우스 전단벽체의 내진성능평가)

  • 이재석;이승은;홍건호;김원기
    • Journal of the Earthquake Engineering Society of Korea
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    • v.6 no.6
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    • pp.65-72
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    • 2002
  • This study estimates steel house shear wall's seismic performance depending on trend of seismic design. As a result at cyclic-test, the capability of energy dissipation about X1SPCH during this test is good enough. The capability of energy dissipation of X3SPCH and X4SPCH was better than that of X1SPCH. The X2SPCH which is similar to real X-braced shear wall has better seismic performance than shear wall braced with structural sheathing materials on pseudo-dynamic test.

Scate: A Scalable Time and Energy Aware Actor Task Allocation Algorithm in Wireless Sensor and Actor Networks

  • Sharifi, Mohsen;Okhovvat, Morteza
    • ETRI Journal
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    • v.34 no.3
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    • pp.330-340
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    • 2012
  • In many applications of wireless sensor actor networks (WSANs) that often run in harsh environments, the reduction of completion times of tasks is highly desired. We present a new time-aware, energy-aware, and starvation-free algorithm called Scate for assigning tasks to actors while satisfying the scalability and distribution requirements of WSANs with semi-automated architecture. The proposed algorithm allows concurrent executions of any mix of small and large tasks and yet prevents probable starvation of tasks. To achieve this, it estimates the completion times of tasks on each available actor and then takes the remaining energies and the current workloads of these actors into account during task assignment to actors. The results of our experiments with a prototyped implementation of Scate show longer network lifetime, shorter makespan of resulting schedules, and more balanced loads on actors compared to when one of the three well-known task-scheduling algorithms, namely, the max-min, min-min, and opportunistic load balancing algorithms, is used.

A Parametric Voice Activity Detection Based on the SPD-TE for Nonstationary Noises (비정체성 잡음을 위한 SPD-TE 기반 계수형 음성 활동 탐지)

  • Koo, Boneung
    • The Journal of the Acoustical Society of Korea
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    • v.34 no.4
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    • pp.310-315
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    • 2015
  • A single channel VAD (Voice Activity Detection) algorithm for nonstationary noise environment is proposed in this paper. Threshold values of the feature parameter for VAD decision are updated adaptively based on estimates of means and standard deviations of past non-speech frames. The feature parameter, SPD-TE (Spectral Power Difference-Teager Energy), is obtained by applying the Teager energy to the WPD (Wavelet Packet Decomposition) coefficients. It was reported previously that the SPD-TE is robust to noise as a feature for VAD. Experimental results by using TIMIT speech and NOISEX-92 noise databases show that decision accuracy of the proposed algorithm is comparable to several typical VAD algorithms including standards for SNR values ranging from 10 to -10 dB.

A Study of the Efficient Planning of Governance for Building Biomass Circulation Estate (바이오매스 순환단지조성을 위한 거버넌스 구축방안 연구)

  • Kwon, Goo-Jung;Lee, Su-Young;Hwang, Jae-Hyun
    • Korean Journal of Organic Agriculture
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    • v.22 no.4
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    • pp.561-579
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    • 2014
  • This research estimates the necessity of a better governance plan on the purpose of fulfillment energy recovery by building resource recycling system for biomass resources and waste resources that derive from agricultural and mountain village areas. The utilization of new renewable energy technology which uses waste and biomass sources diverse as variety of resources, collecting method, operator etc. and is structurally complicated the formation of policy is also very difficult. There is failure because of the problems which occurs from the policy led by government. Biomass Town Development Project should be made through the central government and the local government integrated support system and should be formed a consultative group in order to process the project mutually with these two department including the experts from the related areas. This consultative group, while government organizations carry out the hub function of strategic knowledge management, should carry out the control tower function to be able to be net working transfer the information with the cooperation of private and government so vitalize the communication area among the related actors. And to be able to increase the participation rate of the local people the consistent and various educations should be given so a smooth business promotion progress will be desired through the change of perception and coactive participation of people.

Modeling on thermal conductivity of MOX fuel considering its microstructural heterogeneity

  • Lee, Byung-Ho;Koo, Yang-Hyun;Sohn, Dong-Seong
    • Proceedings of the Korean Nuclear Society Conference
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    • 1999.10a
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    • pp.247-247
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    • 1999
  • This paper describes a new mechanistic thermal conductivity model considering the heterogeneous microstructure of MOX fuel. Even though the thermal conductivities of MOX have been investigated numerously by experimental measurements and theoretical analyses, they show the large scattering making the performance analysis of MOX fuel difficult. Therefore, a thermal conductivity model that depends on the heterogeneous microstructure of MOX fuel has been developed by using a general two-phase thermal conductivity model. In order to apply this model for developing the thermal conductivity for heterogeneous MOX fuel, the fuel is assumed to consist of Purich particles and U02 matrix including Pu02 in solid solution. Since little relevant data on Purich particles is available, FIGARO and SiemensKWU results are only used to characterize the microstructure of unirradiated and irradiated fuel. Philliponneaus and HALDEN models are selected for the local thermal conductivities for Purich particles and matrix, respectively. Then by combining the two models, overall thermal conductivity of MOX fuel is obtained. The new proposed model estimates the MOX thermal conductivity about 10% less than the value of U02 fuel, which is in the range of MOX thermal conductivity from HALDEN. The developed thermal conductivity model has been incorporated into KAERIs fuel performance code, COSMOS, and then verified using the measured data in the FIGARO program. Comparison of predicted and measured temperatures shows the reasonable agreement within acceptable error bounds together with satisfactory results for the fission gas release and gap pressure.essure.

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