• Title/Summary/Keyword: growth modeling

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"Maintenance"-mode feedback and the host galaxies of radio-AGN

  • Karouzos, Marios;Im, Myungshin;Trichas, Markos
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.37.1-37.1
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    • 2014
  • There exists strong evidence supporting the co-evolution of central supermassive black holes and their host galaxies; however it is still under debate how such a relation comes about and whether it is relevant for all or only a subset of galaxies. An important mechanism connecting AGN to their host galaxies is AGN feedback, potentially heating up or even expelling gas from galaxies. AGN feedback may hence be responsible for the eventual quenching of star formation and halting of galaxy growth. A rich multi-wavelength dataset ranging from the X-ray regime (Chandra), to far-IR (Herschel), and radio (WSRT) is available for the North Ecliptic Pole field, most notably surveyed by the AKARI infrared space telescope, covering a total area on the sky of 5.4 sq. degrees. We investigate the star-formation properties and possible signatures of radio feedback mechanisms in the host galaxies of 237 radio-AGN below redshift z=2 and at a radio 1.4 GHz flux density limit of 0.1 mJy. Using broadband SED modeling, the nuclear and host galaxy components of these sources are studied simultaneously as a function of their radio luminosity. Here we present results concerning the AGN content of the radio sources in this field, while offering evidence supporting a "maintenance" type of feedback from powerful radio-jets.

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Biofilm modeling systems (생물막 모델 시스템)

  • Kim, Soo-Kyoung;Lee, Joon-Hee
    • Korean Journal of Microbiology
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    • v.52 no.2
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    • pp.125-139
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    • 2016
  • Biofilms are considered a complexly structured community of microorganisms derived from their attached growth to abiotic and biotic surfaces. In human life, they mediate serious infections and cause many problems in civil and industrial facilities. While it is of huge interest for scientists to understand biofilms, it has been very hard to directly analyze the various biofilms in nature. A variety of biofilm models have been suggested for laboratory-scale biofilm formation and many methods based on these models are widely used for the biofilm researches. These biofilm models mimic characteristics of environmental biofilms with different advantages and disadvantages. In this review, we will introduce these currently used biofilm model systems and explain their relative merits.

Construction of a Temperature-dependent Simulation Model to Predict Population Growth of the German (바퀴, Blattella germanica 개체군 증가의 예측을 위한 온도의존 Simulation Model 의 구성)

  • Chon, Tae Soo;Tae Sung Kwon
    • The Korean Journal of Ecology
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    • v.8 no.4
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    • pp.179-196
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    • 1985
  • By using temperatures as a key variable, a simulation model was constructed to predict the size and developmental speed for the German cockroach population. The following three research steps were conducted to implement the individual simulation technique to represent the basic life system of the cockroach. First, informations on developmental periods and survival rates in each life stage were obtained through rearing experiments at five different temperatures. Secondly, biological parameters needed for modeling were obtained based on these rearing results. The logistic equation was applied to calculating the developmental speed, while the averages of survival rates were utilized as parameters determining population size. And thirdly, a basic life model was constratued in a stimulative framework in FORTRAN for predicting the populating development on the individual basis. For this purpose the biological characteristics, such as life stage, age in days, developmental speed, fecundity, etc., were assigned as an inherent attribute of the transactiion so that they could accompany each individual automatically all through the simulation. This gave the model flexibility and applicability in representing the isnect life system. The save memory space in computer programing, two files were utilized in translocating the individual informations each other as time proceeded. The developed model could be effectively used as a strategic tool in interpreting and managing the cockroach population. It was also suggested in this study that the individual simulation could efficiently serve as a basis to formulate a fundamental framework on which the advanced and complex life process could be built.

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Production of Agrometeorological Information in Onion Fields using Geostatistical Models (지구 통계 모형을 이용한 양파 재배지 농업기상정보 생성 방법)

  • Im, Jieun;Yoon, Sanghoo
    • Journal of Environmental Science International
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    • v.27 no.7
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    • pp.509-518
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    • 2018
  • Weather is the most influential factor for crop cultivation. Weather information for cultivated areas is necessary for growth and production forecasting of agricultural crops. However, there are limitations in the meteorological observations in cultivated areas because weather equipment is not installed. This study tested methods of predicting the daily mean temperature in onion fields using geostatistical models. Three models were considered: inverse distance weight method, generalized additive model, and Bayesian spatial linear model. Data were collected from the AWS (automatic weather system), ASOS (automated synoptic observing system), and an agricultural weather station between 2013 and 2016. To evaluate the prediction performance, data from AWS and ASOS were used as the modeling data, and data from the agricultural weather station were used as the validation data. It was found that the Bayesian spatial linear regression performed better than other models. Consequently, high-resolution maps of the daily mean temperature of Jeonnam were generated using all observed weather information.

Development of Solution Algorithm for Multi-dimention Road Alignment Design Considering Low-Carbon (탄소저감형 다차원 도로선형설계를 위한 솔루션 알고리즘 개발)

  • Kang, Jeon-Yong;Shim, chang-su
    • Journal of KIBIM
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    • v.5 no.4
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    • pp.11-22
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    • 2015
  • Government efforts for green growth policy initiatives demand low-carbon technologies in the road construction industry. The purpose of this paper is to develop an algorithm of a road alignment design solution for establishing the multi-dimensional information, and to calculate carbon emission quantity due to the geometric design elements in the planning phase of road alignment. The paper developed a calculation method for carbon emission quantity by drawing a speed profile reflected in the operating speed, acceleration and deceleration, which are majors factor of carbon emissions while driving and by applying a carbon emission factor. From this effort, it enabled alignment planning to reduce carbon emission. Object-based parametric design methods of the cross-sections were proposed for alignment planning, and the paper demonstrated a BIM-based road alignment planning solution. The proposed solutions can provide multi-dimensional information on carbon emission quantity and cross section elements through driving simulation. It is expected to allow construction of eco-friendly roads by deriving optimal road alignment to minimize environmental costs.

Analysis of Sea-breeze Frontogenesis over the Coastal Urban Area Using Urbanized MM5 (도시형 중규모기상모델을 이용한 연안도시 해풍전선 발달 분석)

  • Hwang, Mi-Kyoung;Oh, In-Bo;Kim, Yoo-Keun
    • Journal of Korean Society for Atmospheric Environment
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    • v.27 no.4
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    • pp.416-425
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    • 2011
  • To analyze the physical processes of sea-breeze development over a coastal urban area, numerical simulation for seabreeze (SB) and its frontogenesis was examined based on urbanized MM5 (uMM5) with urban canopy parameterization. On 6 August 2006, SB and its front were well developed in Busan under a weak offshore flow. As a result of wind vector, ZVB (Zero Velocity Boundary), potential temperature obtained the uMM5, at 0900 LST, SB advanced below 200 m height in the coastal areas and the internal boundary grew with the urban coastal region. At noon, the height of the SB head with updraft was approximately one and a half times (~600 m) higher than its depth in central urban. Applying the frontogenesis function, the SB structure for frontogenesis and frontolysis were complicated spatially; the dynamic effects of wind (i.e. convergence and tilting term) could play an important role in the growth of SB, especially the convergence effect.

Effects of Consumer Self-Determination Motivation and Service Quality on Purchase Intention of Omni-Channel Service in Omni-Channel Environment (옴니채널 환경에서 소비자의 자기결정 동기와 서비스품질이 옴니채널 서비스 구매의도에 미치는 영향)

  • Park, Joonyong;Kim, Ji Su;Kim, Renee B.
    • Journal of Information Technology Services
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    • v.18 no.4
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    • pp.23-38
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    • 2019
  • With the development of information and communication technology, logistics distribution systems and services have been improved, new types of services have been provided, and consumption patterns in consumer markets have also changed. In the domestic distribution market, the development of ICT technology, the spread of smart devices, and the growth of the e-commerce market have led to Omni-channel, a service that integrates offline channels and online channels. Omni-channel service aims to provide consumers with consistent and convenient service by integrating offline and online domain into one. Consumers can get integrated service on and offline. In this study, consumers' intention to use Omni-channel was examined by Self Determination Theory and SERVQUAL. The survey was conducted on Omni-channel user and the research model was composed of 2nd order factor model considering the characteristics of Omni-channel which provides integrated service based on the prior literature and PLS-SEM (partial least squares structural equation modeling).

A Simulation Study on Future Climate Change Considering Potential Forest Distribution Change in Landcover (잠재 산림분포 변화를 고려한 토지이용도가 장래 기후변화에 미치는 영향 모사)

  • Kim, Jea-Chul;Lee, Chong Bum;Choi, Sungho
    • Journal of Environmental Impact Assessment
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    • v.21 no.1
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    • pp.105-117
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    • 2012
  • Future climate according to land-use change was simulated by regional climate model. The goal of study was to predict the distribution of meteorological elements using the Weather Research & Forecasting Model (WRF). The KME (Korea Ministry of Environment) medium-category land-use classification was used as dominant vegetation types. Meteorological modeling requires higher and more sophisticated land-use and initialization data. The WRF model simulations with HyTAG land-use indicated certain change in potential vegetation distribution in the future (2086-2088). Compared to the past (1986-1988) distribution, coniferous forest area was decreased in metropolitan and areas with complex terrain. The research shows a possibility to simulate regional climate with high resolution. As a result, the future climate was predicted to $4.5^{\circ}$ which was $0.5^{\circ}$ higher than prediction by Meteorological Administration. To improve future prediction of regional area, regional climate model with HyTAG as well as high resolution initial values such as urban growth and CO2 flux simulation would be desirable.

A Survey on Appraisal Methods of Maturity Level for Applying to Simulation-based Acquisition (SBA 성숙도 심사 방법론 개발을 위한 조사 연구)

  • Park, Jinsoo;Kim, Yun Bae;Jung, Chul Woo
    • Journal of Information Technology and Architecture
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    • v.9 no.3
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    • pp.265-273
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    • 2012
  • To improve M&S and SBA, it is important that their capability and maturity models should be developed. In general, capability and maturity models provide the standards for growth and improvement as well as the assessment on the organizational maturity level and the process capabilities, which are composed of a standard reference model and appraisal methods. In this paper, following introduction of a standard reference model for SBA in brief, we investigate some appraisal methods by survey and provide frameworks of appraisal method for SBA.

L-system Tree with Particle Attributes (파티클 속성을 사용한 L-시스템 트리)

  • Jou, Wou-Seok;Park, Hyun-Min;Bahng, Soon-Jung
    • The KIPS Transactions:PartA
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    • v.9A no.4
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    • pp.589-594
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    • 2002
  • In computer graphics, L-system is primarily used for the production of such natural shapes as flowers, trees, and grass. It is possible by iteratively applying the theory of multiple-reduction-copy-machine to an arbitrary initial shape. The purpose of this paper is to modify the shape of ordinary L-system trees so that more realistic trees can be generated. Instead of applying simple iterative function system of the L-system, we regard each branch of the trees as a living thing, and endow them with corresponding attributes. Such branch attributes as lifetime, growth speed, shape variation, attraction by environment are known to belong to the attributes of the particle system. We presented modeling methods as hypotheses for each of the attributes based on parameters, iud shown the resulting diverse tree shapes.