• Title/Summary/Keyword: Space Travel

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Deadlock-free Routing of an ACV in Accelerated Motion (가감속을 고려한 교착없는 AGV 주행경로설정)

  • Choe, Ri;Park, Tae-Jin;Ryu, Kwang-Ryel
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.387-392
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    • 2006
  • In the environment where AGVs(Automated Guided Vehicles) operate concurrently in limited space, collisions. deadlocks, and livelocks which have negative effect on the productivity of AGVs occure more frequently. The accelerated motion of an AGV is also the factor that make the AGV routing more difficult because the accelerated motion makes it difficult to estimate the vehicle's exact travel time. In this study, we propose methods of avoiding collisions, deadlocks, and livelocks using OAR(Occupancy Area Reservation) table, and selecting best route by estimating the travel time of an AGV in accelerated motion. A time-driven simulation validated the effectiveness of the proposed methods.

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Exploring Residential Street Environments through Walking Companions and Walking Speeds - A Case Study of Mang-won Neighborhoods with the Elderly Focus Group - (동행여부와 보행속도를 고려한 노인의 근린가로환경 이용특성 해석 - 망원동 사례조사를 중심으로 -)

  • Huh, Jinah;Lee, Sunjae;Park, So-Hyun
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.1
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    • pp.127-138
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    • 2019
  • This study was to evaluate the walking speed of elderly people by using the travel route big data collected by travel diary and smart phone application. We analyzed the change of walking behavior in the residential street environments of the elderly whether they had a company or not. We interpreted the meaning based on previous studies. In addition, the characteristics of elderly people's use of the residential street environment were analyzed by comparing the change in spatial speed according to the companion. The result reveals that the usage patterns of the residential street environments change depending on whether they were accompanied or not. First, the elderly tend to do more social activities while walking alone than when they were accompanied. When they were accompanied the social activities occur in empty lot near the residential area. However, the social activities of the elderly occur in open space such as neighborhood park or playground while walking alone. Finally, This study has strength that it empirically analyzes the elderly's walking behavior and usage paths in small outdoor spaces, including residential streets.

Inter-space Interaction Issues Impacting Middleware Architecture of Ubiquitous Pervasive Computing

  • Lim, Shin-Young;Helal, Sumi
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.8 no.1
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    • pp.42-51
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    • 2008
  • We believe that smart spaces, offering pervasive services, will proliferate. However, at present, those islands of smart spaces should be joined seamlessly with each other. As users move about, they will have to roam from one autonomous smart space to another. When they move into the new island of smart space, they should setup their devices and service manually or not have access to the services available in their home spaces. Sometimes, there will conflicts between users when they try to occupy the same space or use a specific device at the same time. It will also be critical to elder people who suffer from Alzheimer or other cognitive impairments when they travel from their smart space to other visited spaces (e.g., grocery stores, museums). Furthermore our experience in building the Gator Tech Smart House reveals to us that home residents generally do not want to lose or be denied all the features or services they have come to expect simply because they move to a new smart space. The seamless inter-space interaction requirements and issues are raised automatically when the ubiquitous pervasive computing system tries to establish the user's service environment by allocating relevant resources after the user moves to a new location where there are no prior settings for the new environment. In this paper, we raise and present several critical inter-space interactions issues impacting middleware architecture design of ubiquitous pervasive computing. We propose requirements for resolving these issues on seamless inter-space operation. We also illustrate our approach and ideas via a service scenario moving around two smart spaces.

How Did the COVID-19 Pandemic Affect Mobility, Land Use, and Destination Selection? Lesson from Seoul, Korea

  • Lee, Jiwon;Gim, Tae-Hyoung Tommy;Park, Yunmi;Chung, Hyung-Chul;Handayani, Wiwandari;Lee, Hee-Chung;Yoon, Dong Keun;Pai, Jen Te
    • Land and Housing Review
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    • v.14 no.4
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    • pp.77-93
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    • 2023
  • The COVID-19 pandemic has brought about significant social changes through government prevention and control measures, changes in people's risk perceptions, and lifestyle changes. In response, urban inhabitants changed their behaviors significantly, including their preferences for transportation modes and urban spaces in response to government quarantine policies and concerns over the potential risk of infection in urban spaces. These changes may have long-lasting effects on urban spaces beyond the COVID-19 pandemic or they may evolve and develop new forms. Therefore, this study aims to explore the potential for urban spaces to adapt to the present and future pandemics by examining changes in urban residents' preferences in travel modes and urban space use due to the COVID-19 pandemic. This study found that overall preferences for travel modes and urban spaces significantly differ between the pre-pandemic, pandemic, and post-pandemic periods. During the pandemic, preferences for travel modes and urban spaces has decreased, except for privately owned vehicles and green spaces, which are perceived to be safe from transmission, show more favorable than others. Post-pandemic preferences for travel modes and urban spaces are less favorable than pre-pandemic with urban spaces being five times less favorable than transportation. Although green spaces and medical facilities that were positively perceived during the pandemic are expected to return to the pre-pandemic preference level, other factors of urban spaces are facing a new-normal. The findings suggest that the COVID-19 pandemic has had a significant impact on urban residents' preferences for travel modes and urban space use. Understanding these changes is crucial for developing strategies to adapt to present and future pandemics and improve urban resilience.

An Alternative Evaluation Model for Benefit Measurement of Public Transportation by the Open of Urban Railway: Seoul Metro Line 9 (도시 철도개통에 따른 대중교통이용 편익측정을 위한 대안적 평가모델 : 지하철 9호선을 사례로)

  • Joo, Yong-Jin
    • Spatial Information Research
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    • v.19 no.4
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    • pp.11-20
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    • 2011
  • In accordance with low carbon and green growth paradigm, a subway is one of major public transit systems for resolving traffic congestion and decreasing traffic accidents. In addition, as subway networks expand, passengers' travel pattern in the subway network change and consequently affect the urban structure. Generally, new subway route has been planned and developed, mainly considering a travel demand forecast. However, it is desired to conduct an empirical analysis on the forecast model regarding change of travel accessibility and passenger demand pattern according to new subway line. Therefore, in this paper, an alternative method, developed based upon a spatial syntax model, is proposed for evaluating new subway route in terms of passenger's mobility and network accessibility. In a case study, we constructed subway network data, mainly targeting the no 9 subway line opened in 2009. With an axial-map analysis, we calculated spatial characteristics to describe topological movement interface. We then analyzed actual modal shift and change on demand of passengers through the number of subway passenger between subway stations and the number of passenger according to comparative bus line from Smart Card to validate suggested methods. Results show that the proposed method provides quantitative means of visualizing passenger flow in subway route planning and of analyzing the time-space characteristics of network. Also, it is expected that the proposed method can be utilized for predicting a passengers' pattern and its impact on public transportation.

Public Transport Network Connectivity using GIS-based Space Syntax (GIS 기반 Space Syntax를 이용한 대중교통 접근성)

  • Jun, Chul-Min
    • Journal of Korea Spatial Information System Society
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    • v.9 no.3
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    • pp.25-33
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    • 2007
  • The local governments of major cities in Korea are giving focus on public transportation to reduce congestion and improve accessibility in city areas. In this regards, the proper measurement of accessibility is now a key policy requirement for reorganizing the public transport network. Public transport routing problems, however, are considered to be highly complicated since a multi-mode travel generates different combinations of accessibility. While most of the previous research efforts on measuring transport accessibility are found at zone-levels, an alternative approach at a finer scale such as bus links and stops is presented in this study. We proposes a method to compute the optimal route choice of origin-destination pairs and measure the accessibility of the chosen modes combination based on topological configuration. The genetic algorithm is used for the computation of the journey paths, whereas the space syntax theory is used for the accessibility. This study used node-link data in GIS instead of axial lines which are manually drawn in space syntax. The resulting accessibilities of bus stops are calibrated by O-D survey data and the proposed process is tested on a CBD of Seoul.

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Electromagnetic Field and the Poetry of Ezra Pound

  • Ryoo, Gi Taek
    • Journal of English Language & Literature
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    • v.57 no.6
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    • pp.939-958
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    • 2011
  • Ezra Pound has an idea of poetry as a field of energy in which words interact with each other with kinetic energy. The energy field which Pound creates in his poem is analogous to the theory of electromagnetism developed by Michael Faraday and James Maxwell, who look upon the space around magnets, electric charges and currents not as empty but as filled with energy and activity. Pound argues that "words are charged with force like electricity," demonstrating that words charged with their own images or energies of positive or negative valence interact one another. This idea is similar to Faraday's concept of "line of force" which he used to represent the disposition of electric and magnetic forces in space. Pound's concept of "image" as an "intellectual and emotional complex in an instant" is remarkably consonant with the confluence of electric and magnetic fields that are coupled to each other as they travel through space in the form of electromagnetic waves. The instant profusion of conception and perception, much like that of electric and magnetic fields, enables Pound to move beyond the sequential and linear hierarchy in time and space. Particularly, Maxwell's stunning discovery that the electromagnetic waves propagate in space at 'the speed of light' has allowed Pound a relativistic sense of escape from the limitations of Newtonian absolute time and space. Pound's poetry transcends any geographical space and sequential time by rendering and juxtaposing images simultaneously. Pound was fully aware of light and electricity fundamental to what he called his world "the electric world." Pound's experiments in Imagism and Vorticism can be considered an attempt to rediscover a place for poetry in the modern world of science and technology. Almost all the appliances that we think of today as modern were laid down in the closing decades of the 19th century and the first decades of the 20th century, in response to the availability of electromagnetic energy. This paper explores how Pound responded to the age of modern technology and science, examining his conception of "image" through his many analogies and similes drawn from electromagnetism. Pound's imagist poetics and poetry come to embody, not only the characteristics of the electric age in the early twentieth century, but the principles of electromagnetism the electric age is based upon.

A GIS-based Analysis of Spatial Patterns of Individual Accessibility: A Critical Examination of Spatial Accessibility Measures (GIS를 이용한 접근성의 공간적 패턴 분석: 공간적 접근성 측정방법에 대한 비판적 검토)

  • Kim Hyun-Mi
    • Journal of the Korean Geographical Society
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    • v.40 no.5 s.110
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    • pp.514-532
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    • 2005
  • The purpose of this study is to critically examine conventional spatial measures of individual accessibility, which are based on the notion of spatial proximity, the single reference location, and the unlinked travel model. Using space-time accessibility measures with the travel-activity diary data set of Portland Metro, US, three expectations from spatial measures on spatial patterns of individual accessibility were empirically examined: (1) does individual accessibility decrease with an increase of distance from the CBD?; (2) does the spatial pattern of accessibility resemble that of urban opportunity density pattern?; and (3) are spatial patterns of individual accessibility of different socio- demographic population groups basically similar as people in the same area share the same geographic characteristics regardless of gender, race, age, and so on? First of all, the results showed that spatial variations in individual accessibility were not directly determined by spatial proximity and opportunity density as suggested by previous accessibility measures. The spatial pattern of individual accessibility was dramatically different from that of urban opportunity density High peaks of accessibility level were found far away from the CBD and regional centers. This finding might be associated with the importance of multi-reference locations and linked travels in shaping accessibility in reality. Furthermore, this study found that spatial patterns of accessibility clearly differ between men and women. These findings suggest that access requires more than proximity, and that the interaction between person-specific space-time constraints and the consequential availability of urban opportunities in space-time renders different accessibility experiences to people even in the same region, which would be one of the key ingredients missing from conventional spatial measures of accessibility.

[Fe II] $1.64{\mu}m$ Outflow Features around Ultracompact H II Regions in the First Galactic Quadrant

  • Shinn, Jong-Ho;Kim, Kee-Tae;Lee, Jae-Joon;Lee, Yong-Hyun;Kim, Hyun-Jeong;Pyo, Tae-Soo;Koo, Bon-Chul;Kyeong, Jaemann;Hwang, Narae;Park, Byeong-Gon
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.68.2-69
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    • 2015
  • We present [Fe II] $1.644{\mu}m$ features around ultracompact H II regions (UCHIIs) found on a quest for the "footprint" outflow features of UCHIIs -the features produced by outflowing materials ejected during an earlier, active accretion phase of massive young stellar objects (MYSOs). We surveyed 237 UCHIIs in the first Galactic quadrant, employing the CORNISH UCHII catalog and UWIFE data, which is an imaging survey in [Fe II] $1.644{\mu}m$ performed with UKIRT-WFCAM under ~0.''8 seeing conditions. The [Fe II] features were found around five UCHIIs. We interpret the [Fe II] features to be shock-excited by outflows from YSOs and estimate the outflow mass-loss rates from the [Fe II] flux which are ${\sim}1{\times}10^{-6}-4{\times}10^{-5}M{\odot}yr^{-1}$. We propose that the [Fe II] features might be the "footprint" outflow features, but more studies are required to clarify whether or not this is the case. This is based on the morphological relation between the [Fe II] and 5 GHz radio features, the outflow mass-loss rate, the travel time of the [Fe II] features, and the existence of several YSO candidates near the UCHIIs.

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A Study on the Symbolic Recognition Structure System of Space Design of a Hotel (호텔 공간디자인의 상징적 인식구조체계에 관한 연구)

  • Kim, Jeong-Ah;Kim, Uk
    • Korean Institute of Interior Design Journal
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    • v.17 no.4
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    • pp.92-101
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    • 2008
  • A new paradigm of design lays stress on the world of metaphysical concepts, and various attempts are being made to give meaning to psychological values. Hotel is a memorable place to remind of a special moment in one's life such as travel, marriage, meeting and so on. It also contains even more symbolism than other spaces as it is the place where the most primary and private act takes place apart from one's residence. As a result, it is also possible to communicate the message which a designer intends to convey through the user's recognition in the form of various symbolic expressions in space design. The designer communicates a meaning into a space through a symbolic system and creates a mutual consensus by means of the understanding structure of "designer-space-user". The user's diverse interpretations through a symbol are based on epistemology and consist of the primary, the secondary and the tertiary recognition structure system in the aspect of their contents. The primary structure depends on sensual perception, impressive idea and transcendental recognition based on metaphysical and perceptional association. The secondary structure includes casualty, continuous deduction and rational(integral) recognition. Finally, the tertiary structure is sublimation to the transcendental mental world beyond the boundary of emotion and it is classified into fundamental recognition structure on an object and archetypical recognition structure on an ego. These characteristics can derive systematic understandings and diverse interpretations on the symbol from the space of a hotel through the frame of analysis based on the artistic form of monosemous, polysemous and multidimensional frameworks and symbols. The framework of this analysis includes all the cases, and various methods which haven't been attempted in practice are presented. Therefore this study is not just a simple analysis of space but rather it will serve as a methodological tool for design that allows for various attempts of symbolic design concepts in the recognition structure system.