• Title/Summary/Keyword: line source model

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Sidewalk Gaseous Pollutants Estimation Through UAV Video-based Model

  • Omar, Wael;Lee, Impyeong
    • Korean Journal of Remote Sensing
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    • v.38 no.1
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    • pp.1-20
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    • 2022
  • As unmanned aerial vehicle (UAV) technology grew in popularity over the years, it was introduced for air quality monitoring. This can easily be used to estimate the sidewalk emission concentration by calculating road traffic emission factors of different vehicle types. These calculations require a simulation of the spread of pollutants from one or more sources given for estimation. For this purpose, a Gaussian plume dispersion model was developed based on the US EPA Motor Vehicle Emissions Simulator (MOVES), which provides an accurate estimate of fuel consumption and pollutant emissions from vehicles under a wide range of user-defined conditions. This paper describes a methodology for estimating emission concentration on the sidewalk emitted by different types of vehicles. This line source considers vehicle parameters, wind speed and direction, and pollutant concentration using a UAV equipped with a monocular camera. All were sampled over an hourly interval. In this article, the YOLOv5 deep learning model is developed, vehicle tracking is used through Deep SORT (Simple Online and Realtime Tracking), vehicle localization using a homography transformation matrix to locate each vehicle and calculate the parameters of speed and acceleration, and ultimately a Gaussian plume dispersion model was developed to estimate the CO, NOx concentrations at a sidewalk point. The results demonstrate that these estimated pollutants values are good to give a fast and reasonable indication for any near road receptor point using a cheap UAV without installing air monitoring stations along the road.

Inference of Chromospheric Plasma Parameters on the Sun from Strong Absorption Lines

  • Chae, Jongchul;Madjarska, Maria S.;Kwak, Hannah;Cho, Kyuhyoun
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.44.4-45
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    • 2020
  • The solar chromosphere can be observed well through strong absorption lines. We infer the physical parameters of chromospheric plasmas from these lines using a multilayer spectral inversion. This is a new technique of spectral inversion. We assume that the atmosphere consists of a finite number of layers. In each layer the absorption profile is constant and the source function is allowed to vary with optical depth. Specifically, we consider a three-layer model of radiative transfer where the lowest layer is identified with the photosphere and the two upper layers are identified with the chromosphere. This three-layer model is fully specified by 13 parameters. Four parameters can be fixed to prescribed values, and one parameter can be determined from the analysis of a satellite photospheric line. The remaining eight parameters are determined from a constrained least-squares fitting. We applied the multilayer spectral inversion to the spectral data of the Hα and the Ca II 854.21 nm lines taken in a quiet region by the Fast Imaging Solar Spectrograph (FISS) of the Goode Solar Telescope (GST). We find that our model successfully fits most of the observed profiles and produces regular maps of the model parameters. We conclude that our multilayer inversion is useful to infer chromospheric plasma parameters on the Sun.

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A case study for the dispersion parameter modification of the Gaussian plume model using linear programming (Linear Programming을 이용한 가우시안 모형의 확산인자 수정에 관한 사례연구)

  • Jeong, Hyo-Joon;Kim, Eun-Han;Suh, Kyung-Suk;Hwang, Won-Tae;Han, Moon-Hee
    • Journal of Radiation Protection and Research
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    • v.28 no.4
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    • pp.311-319
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    • 2003
  • We developed a grid-based Gaussian plume model to evaluate tracer release data measured at Young Gwang nuclear site in 1996. Downwind distance was divided into every 10m from 0.1km to 20km, and crosswind distance was divided into every 10m centering released point from -5km to 5km. We determined dispersion factors, ${\sigma}_y\;and\;{\sigma}_z$ using Pasquill-Gifford method computed by atmospheric stability. Forecasting ability of the grid-based Gaussian plume model was better at the 3km away from the source than 8km. We confirmed that dispersion band must be modified if receptor is far away from the source, otherwise P-G method is not appropriate to compute diffusion distance and diffusion strength in case of growing distance. So, we developed an empirical equation using linear programming. An objective function was designed to minimize sum of the absolute value between observed and computed values. As a result of application of the modified dispersion equation, prediction ability was improved rather than P-G method.

A Cost Estimation Technique using the PRICE S Model for Embedded Software in Weapon Systems (PRICE S 모델을 이용한 무기체계 내장형 소프트웨어 비용 추정 기법)

  • Shin, Eon-Hee;Kang, Sung-Jin
    • The KIPS Transactions:PartD
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    • v.13D no.5 s.108
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    • pp.717-724
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    • 2006
  • The cost estimation of software is getting more important as the portion of software is increasing in acquiring weapon systems. However, the cost estimation of embedded software in a weapon system follows the cost estimation method for general purpose softwares and uses the PRICE S model as a tool. However, any validation result of the estimated cost through an evaluated software size is not well known. Hence, we propose an approach to estimate the cost through evaluating the embedded software site in weapon systems. In order to achieve our research goal, we evaluate the software size of using the line of codes and function points which are produced by the PRICE S model. Finally, we compare the estimated cost data the actual cost data provided by the production company. As a result, we propose an approach to estimate the size and the cost of embedded software in weapon systems which are not easy to estimate objectively. We also expect that the Proposed approach is used for the cost validation and negotiation in the acquisition of weapon systems in the future.

An Experimental Study on the Thermal Performance Measurement of Standing Column Well type Borehole Heat Exchanger (스탠딩컬럼웰형(SCW) 지중열교환기의 열성능 측정에 관한 실험적 연구)

  • Lee, Sanghoon;Choe, Yongseok;An, Kunmuk
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.122.2-122.2
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    • 2010
  • Knowledge of ground thermal properties is most important for the proper design of BHE(borehole heat exchanger) systems. The configure type, pipe size and thermal performance of the BHE is highly dependent on the ground source heatpump system-efficiency and instruction cost. Thermal response tests with mobile measurement devices were developed primarily for in-situ determination of design data for Standing Column Well apply. The main purpose has been to determine in-situ values of effective ground thermal conductivity and thermal resistance, including the effect of ground-water flow and natural convection in the boreholes. The test rig is set up on a some trailer, and contains a sub-circulation pump, a boiler, temperature sensors, flow meter and a data logger for recording the temperature and circulation fluid flow data. A constant heating power is injected into the SCW through the test rig and the resulting temperature change in the SCW is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective in-situ values of rock thermal conductivity and thermal resistance of SCW.

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A POSSIBLE APPLICATION OF CHAOTIC ANALYSIS FOR THE INVESTIGATE OF THE INSULATION DEGRADATION CAUSED BY THE VARIOUS DEFECTS (다양한 절연열화 분석을 위한 카오스 분석방법 적용 연구)

  • Yun, Jeung-Hoon;Lim, Yun-Sok;Koo, Ja-Yoon
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1606-1608
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    • 2001
  • In connection with the monitoring of the insulation degradation of the large power apparatus, a statistical treatment, such as phase resolved partial discharge analysis (PRPDA) has been established for the on-line monitoring system during the past two decades. However, it has shown some inconveniences to distinguish the nature of the PD source in power apparatus. In this regard, a novel approach based on the chaotic analysis(CAPD) is proposed describing the fundamental ideas, outcomes and different view points from conventional PRPDA. In order to make a model for the possible defects causing sudden failures in service, several types of specimen were prepared. And partial discharge signals, originated from those samples, were measured and analyzed by means of PRPDA and CAPD respectively. In this paper, it seems that the correlation between the consecutive PD pulses depending on the nature of PD could be investigated by CAPD. Therefore, it could be considered that the nature of PD source can be distinguished more distinctively when the PRPDA is combined with CAPD.

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A Study on the Church Building Type and Design Source of the church architect P. Alwin Schmid - Focused on the Influence of Dominikus Bohm and Rudolf Schwarz - (교회 건축가 알빈 슈미트신부의 성당건축 유형과 디자인 원천에 관한 연구 - 도미니쿠스 뵘과 루돌프 슈바르츠의 영향관계를 중심으로 -)

  • Kim, Jung-Shin
    • Journal of architectural history
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    • v.16 no.4
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    • pp.131-148
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    • 2007
  • This study aims at searching the Church Building Type and Design Sources of a German church architect who had designed many churches and other buildings in Korea. P. Alwin Schmid(1904-1978) had designed 188 Catholic buildings in Korea for 20 years from 1958 to 1978. In his works there are many excellent Catholic ritual buildings. It was caused by his conviction on the theology and the principles of Church Architecture. And His remarkable achievement is affected by the works of Dominikus Bom(1880-1955) and Rudolf Schwarz(1897-1961). Alwin's 5 plan type is relevant to Schwarz' iconographic model, and their approach to 'light' is much the same. But the Character of inner space is the middle of Dominikus Bom and Rudolf Schwarz. His works rotted in the Liturgical Movement had been developed in the line of connection with 20th German church architecture. The works of Dominikus Bom and Rudolf Schwarz played the role of the teacher of Alwin Schwarz.

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An Experimental Study on the Thermal Performance Measurement of Large Diameter Borehole Heat Exchanger(LD-BHE) for Tripe-U Pipes Spacer Apply (3중관용 스페이서를 적용한 대구경 지중열교환기의 성능측정에 관한 연구)

  • Lee, Sang-Hoon;Park, Jong-Woo;Lim, Kyoung-Bin
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.581-586
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    • 2009
  • Knowledge of ground thermal properties is most important for the proper design of large scale BHE(borehole heat exchanger) systems. The type, pipe size and thermal performance of the BHE is highly dependent on the ground source heatpump system-efficiency and instruction cost. Thermal response tests with mobile measurement devices were developed primarily for insitu determination of design data for large diameter BHE for triple-U spacer apply. The main purpose has been to determine insitu values of effective ground thermal conductivity and thermal resistance, including the effect of ground-water flow and natural convection in the boreholes. The test rig is set up on a some trailer, and contains a circulation pump, a inline heater, temperature sensors, flow meter, power analysis meter and a data logger for recording the temperature, fluid flow data. A constant heat power is injected into the borehole through the tripl-U pipes system of test rig and the resulting temperature change in the borehole is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective insitu values of rock thermal conductivity and borehole thermal resistance of large diameter BHE for spacer apply.

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CHAOTIC ANALYSIS OF PARTIAL DISCHARGE (CAPD) AS A NOVEL APPROACH TO INVESTIGATE INSULATION DEGRADATION CAUSED BY THE VARIOUS DEFECTS (다양한 결함으로부터 발생되는 절연열화를 검출하기 위한 새로운 접근기법으로써의 카오스 분석)

  • Kim, Sung-Hong;Park, Jae-Jun;Lim, Yun-Sok;Yun, Jeung-Hoon;Koo, Ja-Yoon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.05c
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    • pp.221-224
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    • 2001
  • In connection with the monitoring of insulation degradation of large power apparatus in order to predict their unexpected service failures, a statistical treatment, such as phase resolved partial discharge analysis(PRPDA), has been established for the on-line monitoring system during the past decades. However, this method has shown some inconveniences to distinguish the nature of the PD source in power apparatus. In this regard, a novel approach based on the chaotic analysis(CAPD) is proposed describing the fundamental ideas, outcomes and different view points from conventional PRPDA. In order to make a model for the possible defects causing sudden failures in service, several types of specimen were prepared. And partial discharge signals, originated from those samples, were measured and analysed by means of PRPDA and CAPD respectively. Throughout this paper, it seems that the correlation between the consecutive PD pulses depending on the nature of PD could be investigated by CAPD. Therefore, it could be considered that the nature of PD source can be distinguished more distinctively when the PRPDA is combined with CAPD.

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OH Emission toward Embedded YSOs

  • Yun, Hyeong-Sik;Lee, Jeong-Eun;Je, Hyerin;Lee, Seokho;Evans, Neal J. II;Wampfler, S.F.
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.64.1-64.1
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    • 2013
  • High energy photons and mechanical energy produced by the process of star formation result in copious FIR molecular and atomic lines, which are important coolants of the system. Photons thermally or mechanically induced could dissociate water in the dense envelope to change relative abundances among the species O, OH, and H2O. Here we analyze OH emission lines toward embedded young stellar objects (YSOs) observed as part of the Herschel open time key program, 'Dust, Ice, and Gas In Time (DIGIT)' in order to study the physical conditions of associated gas and the energy budget loaded on the OH line emission. According to our analysis of the Herschel/PACS spectra, OH emission peaks at the central spaxel in most of sources, but several sources show spatially extended emission structures. In the extended emission sources, the distribution of OH emission is correlated with that of [OI] emission and extended along the outflow directions. Considering the diversity of source properties, ratios between detected OH lines are relatively constant among sources. In addition, each OH line has strong correlation with bolometric luminosity. For detail analyses with rotation diagram and non-LTE LVG model, we present the results from GSS30-IRS1 and Elias29.

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