• Title/Summary/Keyword: spreading model

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Rapid construction delivery of COVID-19 special hospital: Case study on Wuhan Huoshenshan hospital

  • Wang, Chen;Yu, Liangcheng;Kassem, Mukhtar A.;Li, Heng;Wang, Ziming
    • Advances in Computational Design
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    • v.7 no.4
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    • pp.345-369
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    • 2022
  • Infectious disease emergency hospitals are usually temporarily built during the pneumonia epidemic with higher requirements regarding diagnosis and treatment efficiency, hygiene and safety, and infection control.This study aims to identify how the Building Information Modeling (BIM) + Industrialized Building System (IBS) approach could rapidly deliver an infectious disease hospital and develop site epidemic spreading algorithms. Coronavirus-19 pneumonia construction site spreading algorithm model mind map and block diagram of the construction site epidemic spreading algorithm model were developed. BIM+IBS approach could maximize the repetition of reinforced components and reduce the number of particular components. Huoshenshan Hospital adopted IBS and BIM in the construction, which reduced the workload of on-site operations and avoided later rectification. BIM+IBS integrated information on building materials, building planning, building participants, and construction machinery, and realized construction visualization control and parametric design. The delivery of Huoshenshan Hospital was during the most critical period of the Coronavirus-19 pneumonia epidemic. The development of a construction site epidemic spreading algorithm provided theoretical and numerical support for prevention. The agent-based analysis on hospital evacuation observed "arched" congestion formed at the evacuation exit, indicating behavioral blindness caused by fear in emergencies.

Dynamic Control of Random Constant Spreading Worm using Depth Distribution Characteristics

  • No, Byung-Gyu;Park, Doo-Soon;Hong, Min;Lee, Hwa-Min;Park, Yoon-Sok
    • Journal of Information Processing Systems
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    • v.5 no.1
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    • pp.33-40
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    • 2009
  • Ever since the network-based malicious code commonly known as a 'worm' surfaced in the early part of the 1980's, its prevalence has grown more and more. The RCS (Random Constant Spreading) worm has become a dominant, malicious virus in recent computer networking circles. The worm retards the availability of an overall network by exhausting resources such as CPU capacity, network peripherals and transfer bandwidth, causing damage to an uninfected system as well as an infected system. The generation and spreading cycle of these worms progress rapidly. The existing studies to counter malicious code have studied the Microscopic Model for detecting worm generation based on some specific pattern or sign of attack, thus preventing its spread by countering the worm directly on detection. However, due to zero-day threat actualization, rapid spreading of the RCS worm and reduction of survival time, securing a security model to ensure the survivability of the network became an urgent problem that the existing solution-oriented security measures did not address. This paper analyzes the recently studied efficient dynamic network. Essentially, this paper suggests a model that dynamically controls the RCS worm using the characteristics of Power-Law and depth distribution of the delivery node, which is commonly seen in preferential growth networks. Moreover, we suggest a model that dynamically controls the spread of the worm using information about the depth distribution of delivery. We also verified via simulation that the load for each node was minimized at an optimal depth to effectively restrain the spread of the worm.

Efficiency of Model Oil Fences for One Vessel Using a Physical Experiment and Numerical Calculation (모형 실험과 수치 해석을 통한 단선용 모형 오일펜스의 성능 해석)

  • Kim, Tae-Ho;Jang, Duck-Jong;Yang, Kyung-Uk;Na, Sun-Chol;Kim, Dae-An
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.2
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    • pp.140-149
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    • 2008
  • This study evaluated the efficiency of an oil fence and spreading devices for one vessel in a towing tank. A series of model experiments and numerical calculations were conducted using an existing oil fence for two vessels and a new method for one vessel. Models of the oil fence and spreading devices were constructed on $1/20^{th}$ scale from waterproofed nylon fabric and canvas. The tensions acting on the model of the oil fences and the horizontal distance between the spreading devices were calculated numerically while the oil fences were being towed. The results were extremely close to the results of the model experiments. The ratio of the opening width to the total length of the oil fence, which shows the efficiency of the oil fence for one vessel, was 49.7% in 0.4 m/sec. Therefore, the proposed oil fence system should be very useful for oil containment at sea. As the opening width of the oil fence is not proportional to the length of the towing rope, it may be reasonable to maintain the towing rope at approximately 100 m. Furthermore, a reasonable towing speed, when operating the oil fence for one vessel equipped with spreading devices, was within 0.4 m/sec.

Investigation of Reducing Characteristics for the Spreading of Dredging Soil and the Diffusion of Contaminant by Silt Protector Curtain through Three Dimensional Numerical Model Experiment (3차원 수치모형실험을 통한 오탁방지막의 오염물질 및 준설토 확산 저감특성 조사)

  • Hong, Nam-Seeg
    • Journal of Ocean Engineering and Technology
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    • v.24 no.4
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    • pp.78-85
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    • 2010
  • This study investigates reducing characteristics for the spreading of dredged soil and the diffusion of contaminant by silt protector curtain through three dimensional numerical experiment. The numerical medel is modified by combining the sediment transport characteristics for cohesive sediment into the previously developed model. Several numerical experiments have been given in order to investigate the reducing effect of silt protector using two dimensional numerical channel model under various parameters such as upstream flow velocity, depth of silt curtain and the position of dumped materials. Through the evaluation of several simulation results, we knew that the careful design has to be given in the determination of depth and position of silt protector.

The Spread of Internet Worms on Convergence Networks (융합망 환경에서 인터넷 웜 확산 방식 연구)

  • Shin, Weon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.3B
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    • pp.551-557
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    • 2010
  • Fast spreading Internet worms will be sure to become one of the new major threats of convergence networks as well as the Internet. In order to defend and respond them, it is necessary to study how Internet worms propagate and what factors affect worm spreading. In this paper, we try to describe the correct spread of worms on convergence network environments. Therefore we propose a spreading model and analyze the spreading effects by various experiments.

A Study on the Spread of Internet Worms by Internet Environments (인터넷 환경에 따른 인터넷 웜 확산 방식 연구)

  • Shin, Weon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.1
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    • pp.81-86
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    • 2008
  • Fast spreading Internet worms, such as Code Red and Slammer, have become one of the new major throne of the Internet recently. In order to defend against theses worms, it is essential to understand how Internet worms propagate and how different Internet factors affect worm spreading. In this paper, we intend to describe the spread of worms on Internet environments accurately. Therefore we model and analyze the spreading effects by various simulations considering Internet addressing and speed. The results lead to a better prediction of the worm spreading on current and future Internet environments.

Oil Spill Spreading of Continuous Spills

  • Lee, Jung-Lyul;Chu, Jin-Kyu
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1998.09a
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    • pp.40-44
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    • 1998
  • Since oil spills discharged by offshore oil production platforms, ship accidents etc., cause many environmental problems, forecasts of drift and spreading of the spilled oil are requested as a basis for oil spill combat management. The numerical approach has been thought as the most effective methods of such forecast. In general, the oil spill model takes into account the trajectory and fate of oil, including drifting, spreading, evaporation, dispersion, emulsification, shoreline standing, and so on. (omitted)

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Modeling of Parasitic Source/Drain Resistance in FinFET Considering 3D Current Flow (3차원적 전류 흐름을 고려한 FinFET의 기생 Source/Drain 저항 모델링)

  • An, TaeYoon;Kwon, Kee-Won;Kim, SoYoung
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.10
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    • pp.67-75
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    • 2013
  • In this paper, an analytical model is presented for the source/drain parasitic resistance of FinFET. The parasitic resistance is a important part of a total resistance in FinFET because of current flow through the narrow fin. The model incorporates the contribution of contact and spreading resistances considering three-dimensional current flow. The contact resistance is modeled taking into account the current flow and parallel connection of dividing parts. The spreading resistance is modeled by difference between wide and narrow and using integral. We show excellent agreement between our model and simulation which is conducted by Raphael, 3D numerical field solver. It is possible to improve the accuracy of compact model such as BSIM-CMG using the proposed model.

A Numerical Study of the Effect off Fire Growth Model on Fire Characteristics in a Carriage (화재 성장 모델이 객차내 화재 특성에 미치는 영향에 관한 수치해석적 연구)

  • 김성찬;유홍선;최영기;김동현
    • Journal of the Korean Society for Railway
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    • v.7 no.3
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    • pp.180-185
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    • 2004
  • The present study investigates the effect of fire growth model on fire development characteristics in a carriage. The parallel processing version of FDS code is used to simulate the fire driven flow in a carriage and two types of fire growth model which are flame spread model and t$^2$ model are examined for the same geometrical condition. The heat release rates(HRR) of both model are similar each other until 30 s after ignition, but the flame spread model predicts 5 times higher than those of the t$^2$ fire model during the quasi-steady fire period. Maximum heat release rate in the case of flame spread model reaches about to 12 MW at 100 s after fire ignition. Also, various database of fire properties for combustible materials and more elaborate combustion model considering the flame spreading phenomena are required for better predictions of fire development characteristics using numerical simulation.

Why Do People Spread Online Rumors? An Empirical Study

  • Jong-Hyun Kim;Gee-Woo Bock;Rajiv Sabherwal;Han-Min Kim
    • Asia pacific journal of information systems
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    • v.29 no.4
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    • pp.591-614
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    • 2019
  • With the proliferation of social media, it has become easier for people to spread rumors online, which can aggravate the issues arising from online rumors. There are many individuals and organizations that are adversely affected by malicious online rumors. Despite their importance, there has been little research into why and how people spread rumors online, thus inhibiting the understanding of factors that affect the spreading of online rumors. With attention seeking to address this gap, this paper draws upon the dual process theory and the de-individuation theory to develop a theoretical model of factors affecting the spreading of an online rumor, and then empirically tests it using survey data from 211 individuals about a specific rumor. The results indicate that the perceived credibility of the rumor affects the individuals' attitudes toward spreading it, which consequently affects the rumor spreading behavior. Vividness, confirmation of prior beliefs, argument strength, and source credibility positively influence the perceived credibility of online rumors. Finally, anonymity moderates the relationship between attitude toward spreading online rumors and the spreading behavior.