• Title/Summary/Keyword: Diffusion Patterns

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Analysis of High Concentration Diffusion Pattern by Air Pollutions in Port Industry Interfaces

  • Je-Ho Hwang;Sang-Hyung Park;So-Hyun Yun;Si-Hyun Kim
    • Journal of Korea Trade
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    • v.26 no.3
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    • pp.117-136
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    • 2022
  • Purpose - Port is vital for international trade accounting for approximately 80% of world cargo transportation in the global trade sector. Air pollutants emitted owing to the related industry interfaces developed around the port spread throughout the dense population region can have harmful effects on the nearby residents. This study aims to analyze high-concentration diffusion pattern by air pollutants, considering the main management periods by air pollutants. Design/methodology - Employing the concentration criteria per main air pollutant, the analyses of concentration change patterns per air pollutant, wind characteristics that directly affected the air pollutant diffusion, distribution types per air pollutant, and high-concentration diffusion patterns by season according to time changes were conducted. Findings - The substances that caused harmful levels of air pollution in the hinterland living zone of the Busan New Port were PM_10, PM_2.5, and NO_2. Furthermore, the intensive management periods were as follows: For PM_10, 24-h (spring), 12:00-16:00 (summer), 12:00-16:00 (summer), 20:00-12:00 (fall), and 24:00-20:00 (winter), and for PM_2.5, 24-h (all four seasons), and for NO_2, 23:00-04:00 (spring), 23:00-08:00 (summer), and 20:00-08:00 (fall), and 23:00-04:00 (winter). Originality/value - Research finding indicates that regular monitoring and countermeasures to reduce air pollution for each air pollutant makes it possible to achieve effective air quality control in the port and hinterland living zones.

Survey on Students' Understanding of the Concepts of Diffusion and Osmosis and Analysis of Textbooks as Sources of Misconceptions (확산과 삼투 개념에 관한 학생들의 이해도 및 오개념의 원인으로서의 교과서 분석)

  • Kim, Mun-Soo;Chung, Young-Lan
    • Journal of The Korean Association For Science Education
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    • v.17 no.2
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    • pp.191-200
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    • 1997
  • The purpose of this study is to investigate the misconceptions and the understanding of students on diffusion and osmosis, and to examine the shifts in concept development that result from maturation and additional instruction. In addition, the textbooks were assessed for the sources of the misconceptions. The subjects of this study were 195 students in middle school, 191 students in high school and 195 students in university in Seoul. And the multiple-choice test developed by Odom and Barrow(1995) was used. The results were analyzed by two-way ANOVA in the statistical packages SAS. The major findings of this study are as follows. 1. The mean score of the understanding on the concepts of diffusion and osmosis of junior high school students was 31, that of high school students was 51 and that of university students was 67. In this study, the higher grade students got the higher scores, and it showed significant difference(p<0.01). 2. The mean score of girls was higher than that of boys in all grades. And the difference of the score according to gender showed great difference in high school(p<0.01). 3. An analysis of the patterns of misconceptions about diffusion and osmosis indicated that certain misconceptions prevail across grade levels. 4. An analysis of the contents of textbooks indicated that textbooks may be the source of students' misconceptions about diffusion and osmosis.

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The Diffusion Behavier Analysis Caused by High Pressure Natural Gas Leak in Enclosure with and without Ventilation System (I) (밀폐공간 및 강제환기공간에의 천연가스 고압분출 시 농도 확산분포 거동해석 (I))

  • Ha, Tae-Woong;Ha, Jong-Man;Kim, Eun-Ja
    • Journal of the Korean Institute of Gas
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    • v.16 no.4
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    • pp.23-31
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    • 2012
  • The basic understanding of gas diffusion and technology to predict the diffusion phenomena are needed to prepare against a disaster of leakage of natural gas and to design better consistent and reliable gas supply system in enclosure. The experimental results of British Gas Technology Co. are used in present study as a reference of theoretical study using CFD. The present results of 2D CFD analysis for mass flow rate of nozzle release show good agreement with experimental results within 2.6 % error. 3D CFD analysis for the characteristics of natural gas diffusion in enclosure with various ventilation patterns also gives reasonable agreement with experimental results.

A Choice-Based Competitive Diffusion Model with Applications to Mobile Telecommunication Service Market in Korea (선택관점의 경쟁확산모형과 국내 이동전화 서비스 시장에의 응용)

  • Jun, Duk-Bin;Kim, Seon-Kyoung;Cha, Kyung-Cheon;Park, Yoon-Seo;Park, Myoung-Hwan;Park, Young-Sun
    • Journal of Korean Institute of Industrial Engineers
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    • v.27 no.3
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    • pp.267-273
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    • 2001
  • While forecasting sales of a new product is very difficult, it is critical to market success. This is especially true when other products have a highly negative influence on the product because of competition effect. In this paper, we develop a choice-based competitive diffusion model and apply to the case where two digital mobile telecommunication services, that is, digital cellular and PCS services, compete. The basic premise is that demand patterns result from choice behavior, where customers choose a product to maximize their utility. In comparison with Bass-type competitive diffusion models, our model provides superior fitting and forecasting performance. The choice-based model is useful in that it enables the description of such competitive environments and provides the flexibility to include marketing mix variables such as price and advertising.

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Forecasting the Diffusion Process and the Required Scale of R&D Investment of Renewable Energy in Korea Using the Comparative Analogy Method (비교유추법을 이용한 국내 신재생에너지 확산과정 및 필요 R&D 투자규모 예측)

  • Koo, Sanghoi;Lee, Deok Joo;Kim, Taegu
    • Journal of Korean Institute of Industrial Engineers
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    • v.40 no.3
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    • pp.333-341
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    • 2014
  • The purpose of this study is to forecast the penetration rate of renewable energy and a reasonable scale for the R&D investment plan in Korea based on the relationship between the diffusion and R&D investments drawn by analogy from empirical cases of advanced countries. Among numerous candidate developed countries, the German market was chosen based on the similarity of the diffusion patterns to those of the Korean plan. We then figured out how the investment triggers the growth of technology from the selected benchmark, and applied the technology S-curve relation formula to derive the desirable investment plan for Korea. The present paper is a pioneering attempt to forecast the diffusion process of renewable energy technology in Korea using the comparative analogy from cases of advanced countries.

A Inquiry of Tracer Gas for Analysis of Dispersion and Prediction of Infection Possibility according to Airborne Viral Contaminants (건축공간에서 공기 감염균 확산을 해석하기 위한 추적가스 고찰과 농도에 따른 감염 위험성 예측 연구)

  • Lim, Tae-Seob;Kang, Seung-Mo;Kim, Byung-Seon
    • Korean Institute of Interior Design Journal
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    • v.18 no.3
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    • pp.102-113
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    • 2009
  • The SARS virus began to appear and spread in North America and Southeast Asia in the early 2000' s, infecting and harming many people. In the process of examining the causes for the virus, studies on the airborne SARS virus and the way it spread were carried out mainly in the medical field. In the field of architecture, studies were done on the diffusion of air pollutants in buildings using gases such as $CO_2$, $N_2O$, or $SF_6$, but research on virus diffusion was limited. There were also explanations of only the diffusion process without accurate information and discussion on virus characteristics. The aim of this study is to analyze the physical characteristics of airborne virus, consider the possibility of using coupled analysis model and tracer gas for analyzing virus diffusion in building space and, based on reports of how the infection spread in a hospital where SARS patients were discovered, analyze infection risk using tracer gas density and also diffusion patterns according to the location, shape, and volume of supply diffusers and exhaust grilles. This paper can provide standards and logical principles for evaluating various alternatives for making decisions on vertical or horizontal ward placement, air supply and exhaust installation and air volumes in medium or high story medical facilities.

Adoption of RFID Household-based Waste Charging System in Gangnam and Seocho in Seoul:Based on Technology Hype Curve Model

  • Lee, Sabinne
    • International Journal of Contents
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    • v.15 no.2
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    • pp.1-12
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    • 2019
  • Despite their various similarities, Seoul's' Gangnam and Seocho districts showed different patterns in the adoption of the RFID household-based waste charging system. Gangnam, one of the 25 wealthiest districts in Seoul, first adopted the RFID system in 2012, but decided abandon it a year later due to inconvenience, sanitation, budget limitations, and management related issues. Unlike Gangnam, Seocho, a largely similar district to Gangnam, started to implement the RFID system in 2015 and successfully adopted this innovation. In this paper, we explain the adoption behaviors of these two districts using a Technology Hype Curve Model with 5 stages. Unlike traditional technology adoption theory, the Hype Curve Model concentrates on the big chasm between early majorities and late majorities, which is a core reason for discontinuity in innovation diffusion. Based on our case study result, the early majority easily gave up adoption due to immature technological and institutional infrastructure. However, Seocho district, who waited until the deficiencies had been sufficiently fixed since late majorities, succeeded at incremental diffusion. Since its invention by Gartner cooperation, the Hype Curve Model has not received enough attention in academia. This paper demonstrates its explanatory power for innovation diffusion. Similarly, this paper focuses on the importance of institutional framework in the diffusion of innovation. Lastly, we compare the behavior of two local governments in supporting and diffusing RFID systems to draw relevant policy implications for innovation diffusion.

An Adaptive Framework for Forecasting Demand and Technological Substitution

  • Kang, Byung-Ryong;Han, Chi-Moon;Yim, Chu-Hwan
    • ETRI Journal
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    • v.18 no.2
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    • pp.87-106
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    • 1996
  • This paper proposes a new model as a framework for forecasting demand and technological substitution, which can accommodate different patterns of technological change. This model, which we named, "Adaptive Diffusion Model", is formalized from a conceptual framework that incorporates several underlying factors determining the market demand for technological products. The formulation of this model is given in terms of a period analysis to improve its explanatory power for dynamic processes in the real world, and is described as a continuous form which approximates a discrete derivation of the model. In order to illustrate the applicability and generality of this model, time-series data of the diffusion rates for some typical products in electronics and telecommunications market have been empirically tested. The results show that the model has higher explanatory power than any other existing model for all the products tested in our study. It has been found that this model can provide a framework which is sufficiently robust in forecasting demand and innovation diffusion for various technological products.

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Analyzing and Forecating of Event Visitation :Applicaton of Bass'Model of Diffusion Process (배스의 확산모형을 이용한 이벤트 방문수요 상측에 관한 연구)

  • 엄서호
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.1
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    • pp.51-58
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    • 1998
  • The opening of an event in a given geographical area may be defined as an innovation. Visitors to the event adopt the innovation; therefore, their visitation patterns since the opening can be regarded as a diffusion process. Bass' model of diffusion process was applied to analyzing weekly visitation of Kwang-ju Viennale. Parameters of the Bass' model were estimated by regression analysis, and then reviewed in terms of applicability. Actual estimation of event visitation was implemented by calculation of the three parameters of the model based on the actual data. After comparing estimated value with actual value, it was concluded that Bass' model is applicable to estimating event visitation as far as it is the only prediction method available at this point.

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A Choice-Based Substitutive Diffusion Model for Forecasting Analog and Digital Mobile Telecommunication Service Subscribers in Korea (국내 아날로그와 디지털 이동전화 서비스 가입자 수 예측을 위한 선택 관점의 대체 확산 모형)

  • 전덕빈;박윤서;김선경;박명환;박영선
    • Korean Management Science Review
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    • v.19 no.2
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    • pp.125-137
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    • 2002
  • The telecommunications market is expanding rapidly and becoming more substitutive. In this environment, demand forecasting is very difficult, yet important for both practitioners and researchers. in this paper, we adopt the modeling approach proposed dy Jun and Park [6]. The basic premise is that demand patterns result from choice behavior, where customers choose a product to maximize their utility. We apply a choice-based substitutive diffusion model to the Korean mobile telecommunication service market where digital service has completely replaced analog service. In comparison with Bass-type multigeneration models. our model provides superior fitting and forecasting performance. The choice-based model is useful in that it enables the description of such complicated environments and provides the flexibility to include marketing mix variables such as price and advertising in the regression analysis.