• 제목/요약/키워드: Environment Parameter

검색결과 1,334건 처리시간 0.03초

차량 통신 기술을 위한 MLMEX 설계 및 구현 (The MLMEX Design and Implemention for Vehicle Communication Technology)

  • 이대식;이용권
    • 디지털산업정보학회논문지
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    • 제9권1호
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    • pp.103-110
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    • 2013
  • WAVE system is a vehicle communication technology. The system provides the services to prevent vehicle accidents that might occur during driving. Also, it is used to provide various services such as monitoring vehicle management and system failure. In this paper, we divide module that manages WAVE MAC state into a WSMP base MLME module and IP base module and we design and implement a parameter environment between WME module to manage the state of the WAVE system and MLMEX module to mange IP base of WAVE MAC therefore the date to be processed.Also, in order to verify the validity, we have carried out experiments to compare the speed of data processing by dividing data of 5Mbyte, 10Mbyte, 20Mbyte into the packets of 2KByte and 4KByte. Therefore, in WAVE system, the Parameter environments and data processing speed between WME and MLMEX module can be utilized in the various service of vehicle communication technology depending on the speed of data processing.

Distribution and Characteristics of PAHs in Bivalves from Gwangyang Bay, Korea

  • Yim, U.H.;Hong, S.H.;Shim, W.J.;Oh, J.R.
    • 환경생물
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    • 제22권
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    • pp.78-85
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    • 2004
  • Polyeyclic aromatic hydrocarbons (PAHs) were quantitatively determined in bivalves from Gwangyang Bay. Twenty-four kinds of target PAHs were detected in the entire samples. Total PAHs concentrations ranged 86.1∼1,210 ng g$\^$-1/ dry weight with a average concentration of 309 ng g$\^$-1/, which is much lower than those of other industrialized bays in Korea. Strong tidal currents and artificial interferences like reclamation and dredging activity were suggested as major reason for disparity between highly industrialization and low contamination status. There was no correlation between total PAHs and lipid contents, implying that lipid content is not the one major parameter for the accumulation of PAHs by bivalves. Input sources were inferred as petrogenic and pyrogenic PAHs. With help of PCA analysis, signals of seasonal variations, not only concentrations but also compositions were found.

주거 및 사무환경소음에 대한 주관적 평가 (Subjective Evaluation of The Noise in Residential and Working Environment)

  • 전진용;김경호;정정호;조문재
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 I
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    • pp.114-119
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    • 2001
  • The subjective unwantedness felt from the noise sources in living and office environment has been evaluated by investgating the upper/lower limit of perceptual loudness of the noise. The limits were selected by the subject and the noise sources were analyzed to find out whether there is any correlation with Zwicker parpmeters and ACF fastors. It was found that the loudness of vacuum cleaner noise does not influence its perceived noiseness. Noises implicated in human such as floor walking noise and talking sound, are the most irritating noise in office environment.

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극저온 환경하에서 레이저 용접된 비결정질 재료의 특성에 관한 연구 (Investigation of the Properties of Laser-Welded Amorphous Metal in a Deep Frozen Environment)

  • 이건상
    • Journal of Welding and Joining
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    • 제15권3호
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    • pp.99-108
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    • 1997
  • For the conventional welding method, the high heat transfer makes the crystallization of the work material unavoidable. Whereas the laser is able to weld the amorphous metal without a crystallized zone, because heat transfer is limited withn a very small restricted volume. In this paper, the possibilities and the limits of the laser welding in a deep frozen environment by liquid nitrogen were studied to utilize the advantageous properties of amorphous metal foils. The author investigated, after laser welding in a deep frozen environment with a solid state laser (Nd:YAG-laser), the achievable strengths and the influences of the laser beam parameters on the strengths.

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도시 환경음의 쾌적성 평가를 통한 새로운 지수 적용가능성 분석 (Feasibility of Alternative Physical Parameters by Subjective Evaluation for Urban Environmental Sounds)

  • 박현구;장길수
    • KIEAE Journal
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    • 제8권1호
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    • pp.31-36
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    • 2008
  • For the comfortable housing life, comfortable and pleasant urban environment should be created for the people living in house and in city. There are lots of environmental conditions in city affecting house and life. Also most of all the noise pollution have been become major factor that makes people's life uncomfortable. Recently soundscape researches have been performed to create comfortable urban environment and various studies on the evaluation of urban environmental sounds are now undergoing. This study aimed to analyse the subjective characteristics through the subjective evaluation to the sounds measured with physical parameters and eventually to find out alternative evaluation method for urban environmental sounds. Adjectives applied to previous studies were used for the subjective evaluation and sound sources recorded in specific places were presented with picture at the same time. As a result, new physical parameters such as Lmax, Unbiased Annoyance, G, N and EmT have a feasibility to evaluation of urban environment sounds in terms of acoustic comfort.

Use of vibration characteristics to predict the axial deformation of columns

  • Moragaspitiya, H.N. Praveen;Thambiratnam, David P.;Perera, Nimal J.;Chan, Tommy H.T.
    • Structural Engineering and Mechanics
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    • 제50권1호
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    • pp.73-88
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    • 2014
  • Vibration characteristics of columns are influenced by their axial loads. Numerous methods have been developed to quantify axial load and deformation in individual columns based on their natural frequencies. However, these methods cannot be applied to columns in a structural framing system as the natural frequency is a global parameter of the entire framing system. This paper presents an innovative method to quantify axial deformations of columns in a structural framing system using its vibration characteristics, incorporating the influence of load tributary areas, boundary conditions and load migration among the columns.

하수방류수의 대장균군 발생에 영향을 미치는 수질인자에 관한 연구 (Studies on the Effect of Water Quality Parameters on Total Coliform Concentrations in Sewage Effluents)

  • 백영석;손진식
    • 한국물환경학회지
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    • 제22권1호
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    • pp.166-171
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    • 2006
  • The objectives of the present paper were to investigate the concentration of total coliform in wastewater effluents and the effect of water chemical and physical characters in it. The most correlated parameter with total coliform was COD. It means that the wastewater treatment efficient effects on total coliform concentration. And we developed predictive model for the total coliform concentration. The estimated parameters for model were COD, temperature, nitrite, chloride, Mn and regression model equation was determined; log (Total Coli.) = 1.861+0.065[COD]+0.038[temperature]-0.0004[$Cl^-$]+3.697[Mn]-0.32 [$NO_2-N$] The developed model provided very strong correlation ($R^2:0.82$) between total coliform and regression equation. The parameters having high sensitivity were COD and temperature. So the study indicated that if the temperature and COD of wastewater effluent were known, we would estimate the concentration of total coliform and decide the most effective usage of chlorine.

PEST를 이용한 임하호유역 HSPF 수문 보정 (Hydrologic Calibration of HSPF Model using Parameter Estimation (PEST) Program at Imha Watershed)

  • 전지홍;김태일;최동혁;임경재;김태동
    • 한국물환경학회지
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    • 제26권5호
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    • pp.802-809
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    • 2010
  • An automatic calibration tool of Hydrological Simulation Program-Fortran (HSPF), Parameter Estimation (PEST) program, was applied at the Imha lake watershed to get optimal hydrological parameters of HSPF. Calibration of HSPF parameters was performed during 2004 ~ 2008 by PEST and validation was carried out to examine the model's ability by using another data set of 1999 ~ 2003. The calibrated HSPF parameters had tendencies to minimize water loss to soil layer by infiltration and deep percolation and to atmosphere by evapotranspiration and maximize runoff rate. The results of calibration indicated that the PEST program could calibrate the hydrological parameters of HSPF with showing 0.83 and 0.97 Nash-Sutcliffe coefficient (NS) for daily and monthly stream flow and -3% of relative error for yearly stream flow. The validation results also represented high model efficiency with showing 0.88 and 0.95, -10% relative error for daily, monthly, and yearly stream flow. These statistical values of daily, monthly, and yearly stream flow for calibration and validation show a 'very good' agreement between observed and simulated values. Overall, the PEST program was useful for automatic calibration of HSPF, and reduced numerous time and effort for model calibration, and improved model setup.

비가압식 막 공정을 통한 정삼투막 성능 평가 (Evaluation of Forward Osmosis (FO) Membrane Performances in a Non-Pressurized Membrane System)

  • 김봉철;부찬희;이상엽;홍승관
    • 한국물환경학회지
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    • 제28권2호
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    • pp.292-299
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    • 2012
  • The objective of this study is to develop a novel method for evaluating forward osmosis (FO) membrane performances using a non-pressurized FO system. Basic membrane performance parameters including water (A) and solute (B) permeability coefficients and unique parameter for FO membrane such as the support layer structural parameter (S) were determined in two FO modes (i.e., active layer faces feed solution (AL-FS) and active layer faces draw solution (AL-DS)). Futhermore, these parameters were compared with those determined in a pressurized reverse osmosis (RO) system. Theoretical water flux was calculated by employing these parameters to a model that accounts for the effects of both internal and external concentration polarization. Water flux from FO experiment was compared to theoretical water fluxes for assessing the reliability of those parameters determined in three different operation modes (i.e., AL-FS FO, AL-DS FO, and RO modes). It is demonstrated that FO membrane performance parameters can be accurately measured in non-pressurized FO mode. Specifically, membrane performance parameters determined in AL-DS FO mode most accurately predict FO water flux. This implies that the evaluation of FO membrane performances should be performed in non-pressurized FO mode, which can prevent membrane compaction and/or defect and more precisely reflect FO operation conditions.

삼각형상 수중구조물 주위의 유동특성에 관한 연구 (A Study on the Flow Characteristics around Underwater Triangular Structure)

  • 한원희;조대환
    • 해양환경안전학회지
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    • 제14권1호
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    • pp.21-27
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    • 2008
  • 삼각형상 구조물은 바다에서 풍요로운 어장을 만들기 위해 용승류를 발생시키기 위한 인공용승구조물의 기본적인 형태로 이용되고 있다. 인공용승류는 많은 양의 영양염류를 포함하고 있는 저층의 바닷물을 해저로부터 표층으로 끌어 올리는 작용을 한다. 이 연구의 목적은 여러 가지 성층계수에 따른 삼각형상 수중구조물 주위의 유동특성을 규명하는 것이다. 회류수조 내에서 삼각형상 구조물 모델을 대상으로 유동특성을 조사하기 위하여 유동가시화 방법을 이용한 실험적 연구를 수행하였고, 입자영상유속계(PIV)를 이용하여 수중구조물 주위의 유동장을 계측하였다. 실험결과 구조물 후상부 영역에서의 용승효과는 수심이 구조물 높이의 2배이고, 성층계수가 약 3.0일 때 가장 좋은 결과가 나타났다. 이러한 정량적인 데이터는 인공용승구조물의 기능적 효율을 결정하는 데에 유용하게 이용될 수 있을 것이다.

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