• 제목/요약/키워드: urban complexity

검색결과 169건 처리시간 0.022초

시각적 질의 계량적 측정기법에 관한 연구 : SBE 기법의 일반화 (A Study on the Quantitative Measurement of Perceived Visual Quality : Test of the SBE Method)

  • 임승빈
    • 한국조경학회지
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    • 제15권2호
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    • pp.91-100
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    • 1987
  • Main purpose of this study is to test the usefulness of the SBE method in measuring ‘complexity’‘beauty’and ‘friendliness’other than ‘preference’. The study results are as follows. 1) The SBE results are as reliable and valid in measuring ‘complexity’‘beauty’and ‘friendliness’as in measuring ‘preference’. However, the degree of reliability and convergent validity can vary according to the inherent charateristics of those abstract quality themselves. 2) The correlation coefficients among the result of rating, SBE, frequency, and paired comparison methods are very high. 3) The perceived beauty of urban residential landscape reaches highest at the higher complexity level than that of the rural residential landscape.

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A Realistic Path Loss Model for Real-time Communication in the Urban Grid Environment for Vehicular Ad hoc Networks

  • Mostajeran, Ehsan;Noor, Rafidah Md;Anisi, Mohammad Hossein;Ahmedy, Ismail;Khan, Fawad Ali
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권10호
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    • pp.4698-4716
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    • 2017
  • Wireless signal transmission is influenced by environmental effects. These effects have also been challenging for Vehicular Ad hoc Network (VANET) in real-time communication. More specifically, in an urban environment, with high mobility among vehicles, a vehicle's status from the transmitter can instantly trigger from line of sight to non-line of sight, which may cause loss of real-time communication. In order to overcome this, a deterministic signal propagation model is required, which has less complexity and more feasibility of implementation. Hence, we propose a realistic path loss model which adopts ray tracing technique for VANET in a grid urban environment with less computational complexity. To evaluate the model, it is applied to a vehicular simulation scenario. The results obtained are compared with different path loss models in the same scenario based on path loss value and application layer performance analysis. The proposed path loss model provides higher loss value in dB compared to other models. Nevertheless, the performance of vehicle-vehicle communication, which is evaluated by the packet delivery ratio with different vehicle transmitter density verifies improvement in real-time vehicle-vehicle communication. In conclusion, we present a realistic path loss model that improves vehicle-vehicle wireless real-time communication in the grid urban environment.

도시형자기부상차량의 반능동 조향장치에 대한 연구 (Study for Semi-Steering system for Urban Maglev)

  • 이남진;강광호;이원상
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.1080-1084
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    • 2011
  • Urban maglev should have such characteristics as not only environmentally friendliness and excellent driving capability but also curve negotiation performance because its routes have many sharp curves. Due to normal mechanism of urban maglev its relative displacements of secondary spring are bigger than conventional railway vehicle and the centering force of levitation magnet is smaller than wheel-on-rail system. These features of maglev affect the curving negotiation and so the additional steering device is to be required on Urban maglev to improve the running performance at sharp curve of less than about R50m. Some developed urban maglev had the passive steering device which consists of mechanical linkage or hydraulic cylinder and closed-route piping. But it has drawback as complexity of layout of understructure of vehicle and functional limitation of passive mechanism regarding transient curve. These demerits could be solved by using active steering system. But it has a weak point that an active device should have actuators and additional inverter or hydraulic power source. In this paper, the semi-active steering system for urban maglev is to be introduced.

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공간디자인에 적용된 프랙탈 특성의 인지생태론적 효과 - 랜드스케이프 패턴을 중심으로 - (Fractal Properties and Cognitive Ecological effects in Space Design - Focused on Landscape Pattern -)

  • 김주미
    • 한국실내디자인학회논문집
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    • 제20권2호
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    • pp.120-130
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    • 2011
  • The purpose of this study is to propose cognitive ecological effects of fractal patterns in space design. This study investigated the perception and cognition problems regarding landscape patterns showing fractal properties from the cognitive perspective instead of the traditional speculative approach. In particular, the researcher has verified that fractal geometry theory and fractal pattern concept provide insight in space aesthetic values and cognitive effects. Research results are as follows. First, most environmentally-friendly fractal urban forms provide cognitive connectivity. In particular, this space provides a positive emotional response and preference to humans and displays self-organized complexity. This study found that such complexity of space form has characteristics corresponding to parallel cognitive structures of the human brain. Simultaneously, the researcher suggests that the fractal landscape pattern is an alternative for stiff and homogenized modern space. Second, fractal patterns provide hierarchical connectivity within the brain through continuous difference and repetition. In particular, self-similarities of fractal patterns administer significant visual grouping and coherence in human perception. It can be determined whether scaling coherence facilitates easier organization in cognitive organization. Third, fractal patterns in space design provide the basic method for achieving the connection between concept, construction, and urban factors. As a result, the researcher has suggested that scale distribution of geometrical factors, such as fractal patterns, an be a design method to connect various space typologies.

Wind flow simulations in idealized and real built environments with models of various level of complexity

  • Abdi, Daniel S.;Bitsuamlak, Girma T.
    • Wind and Structures
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    • 제22권4호
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    • pp.503-524
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    • 2016
  • The suitability of Computational Fluid Dynamics (CFD) simulations on the built environment for the purpose of estimating average roughness characteristics and for studying wind flow patterns within the environment is assessed. Urban models of various levels of complexity are considered including an empty domain, array of obstacles arranged in regular and staggered manners, in-homogeneous roughness with multiple patches, a semi-idealized built environment, and finally a real built environment. For each of the test cases, we conducted CFD simulations using RANS turbulence closure and validated the results against appropriate methods: existing empirical formulas for the homogeneous roughness case, empirical wind speed models for the in-homogeneous roughness case, and wind tunnel tests for the semi-idealized built environment case. In general, results obtained from the CFD simulations show good agreement with the corresponding validation methods, thereby, giving further evidence to the suitability of CFD simulations for built environment studies consisting of wide-ranging roughness. This work also provides a comprehensive overview of roughness modeling in CFD-from the simplest approach of modeling roughness implicitly through wall functions to the most elaborate approach of modeling roughness explicitly for the sake of accurate wind flow simulations within the built environment.

Study on the Failure of Autonomous Mobility in World Network Cities

  • Dae Sung Seo
    • International Journal of Internet, Broadcasting and Communication
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    • 제15권3호
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    • pp.73-81
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    • 2023
  • Globalized cities are currently showing changes due to autonomous driving (AD). It is also maximizing globalization connections in cities where autonomous mobility is as complex as AD. The purpose of this study is to reveal that cities that realize AD and mobility will grow into globalized cities. Several cities, including New York and Shanghai, have attempted and are in progress, but failed cities are increasing. Although the technology of AD and the trust of citizens are prioritized, the city that has built the city's infrastructure is expected to be a city that has succeeded in AD. This is because commercialized cities or AVs will become hubs for mobility globalization, excluding rapid climate change or AV companies, and empirical analysis has been conducted that if AVs fail in metropolitan New York due to urban complexity (population density), urban economy size (GRDP), patents, number of consumers, infrastructure public EV chargers, and road quality. It examines whether the realization of AD by region and country affects overall national innovation. As a result, even if AV succeeds in large cities such as New York, Seoul, which has a higher population density (complexity), has a negative meaning, and a more similar Tokyo has a positive meaning. It can be seen that regional research on AV should also be prioritized in large cities such as Shanghai. This means that in order for AV to be realized in each city, the construction of AI infrastructure data must be actively changed to establish globalization of cities for economic growth as autonomous mobility.

도시철도 종합감시시스템에서 요구되는 객체인식 기능 및 시나리오 (Required Video Analytics and Event Processing Scenario at Large Scale Urban Transit Surveillance System)

  • 박광영;박구만
    • 한국ITS학회 논문지
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    • 제11권3호
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    • pp.63-69
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    • 2012
  • 넓은 지역에서의 종합감시시스템 구축은 인력을 효율적으로 관리할 수 있으며 자동화된 감시망을 구축하여 비감시 지역을 줄일 수 있는 특징이 있다. 본 논문에서는 넓은 지역에서 적용할 수 있는 지능형 종합감시시스템에서 입력되는 비디오의 특징을 위치와 용도별로 분석하여 적합한 비디오 감시 알고리즘을 선택할 수 있는 방안을 제시하였다. 7가지 대표적인 상황으로서 침입, 물건 버림/없어짐, 배회, 혼잡도 측정 등이다.

도시철도 환경에 적합한 지능형 감시카메라 시나리오의 연구 (A Study of Scenario in Intelligent Surveillance Camera for Urban Transit)

  • 장일식;정철준;김형민;안태기;박구만
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2009년도 춘계학술대회 논문집
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    • pp.866-871
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    • 2009
  • In this paper, we introduced design of intelligent surveillance camera system and typical event processing scenario for urban transit. To analyze video, we studied events that frequently occur in surveillance camera system. Scenario is designed for estimation in the case of seven representative situations(designated area invasion, an object left alone, removed object in designated area, object tracking, loitering and congestion measurement) in urban transit. Our system is optimized for low hardware complexity, real time processing and scenario dependent solution.

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Information-based Smart Construction Management of High Rise Building Under the Complex Surrounding Environment in City Core Area

  • Liang, Haoqing;Li, Jian;Song, Weiqing
    • 국제초고층학회논문집
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    • 제10권3호
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    • pp.203-210
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    • 2021
  • With the development of urbanization, the increasing of buildings density in urban core areas result in the complexity of construction environment. High-rise landmark building is always preferred in the construction of urban core areas. Super high-rise buildings construction are facing construction management difficulties due to the complex working conditions and enormous building system, especially with the complex surrounding environment of the urban core area, the construction management of super high-rise buildings in the area requires higher, refined and detailed standard. Based on a super high-rise project in a core area of Shanghai which has 370 m building height and 772,643 m2 building area, with complex surrounding environment, narrow construction site and many super-high-altitude crossing works. With the application of BIM technology, the Internet of Things, the LAN communication and other various intelligent mechanical equipment, information management systems, the efficiency and refinement of construction management are improved, ensuring the smooth implementation of the project while effectively controlling the impact on the surrounding environment.

도심 자율주행을 위한 어텐션-장단기 기억 신경망 기반 차선 변경 가능성 판단 알고리즘 개발 (Attention-LSTM based Lane Change Possibility Decision Algorithm for Urban Autonomous Driving)

  • 이희성;이경수
    • 자동차안전학회지
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    • 제14권3호
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    • pp.65-70
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    • 2022
  • Lane change in urban environments is a challenge for both human-driving and automated driving due to their complexity and non-linearity. With the recent development of deep-learning, the use of the RNN network, which uses time series data, has become the mainstream in this field. Many researches using RNN show high accuracy in highway environments, but still do not for urban environments where the surrounding situation is complex and rapidly changing. Therefore, this paper proposes a lane change possibility decision network by adopting Attention layer, which is an SOTA in the field of seq2seq. By weighting each time step within a given time horizon, the context of the road situation is more human-like. A total 7D vectors of x, y distances and longitudinal relative speed of side front and rear vehicles, and longitudinal speed of ego vehicle were used as input. A total 5,614 expert data of 4,098 yield cases and 1,516 non-yield cases were used for training, and the performance of this network was tested through 1,817 data. Our network achieves 99.641% of test accuracy, which is about 4% higher than a network using only LSTM in an urban environment. Furthermore, it shows robust behavior to false-positive or true-negative objects.