• Title/Summary/Keyword: Critical Gap Acceptance

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Development and Evaluation of Smart Roundabout Using Connected Vehicle (Connected Vehicle을 이용한 Smart Roundabout의 개발과 평가)

  • Kim, Hoe Kyoung;Lee, Young Bin;Yoon, Chil Yong;Oh, Yun Pyo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.1
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    • pp.243-250
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    • 2014
  • Modern roundabouts referred to as relatively safer and more efficient traffic facility than the signalized intersections have been recently deployed and operated and accordingly more research efforts to improve its safety and efficiency have been made so far. This paper introduces a new traffic information system named as Smart Roundabout coupled with Connected Vehicle technique like Vehicle-to-Roadside communication, which has not been attempted before and evaluates its performance with a microscopic simulation model, VISSIM. The proposed system functions to collect driving information of circulating vehicles in the roundabout such as location, speed, critical headway, etc. and help approaching vehicles decide whether to enter the roundabout with an on-board equipment instrumented in the individual vehicle on the basis of calculated gap acceptance of interest. This new system is expected to secure more safety and increase the capacity of the modern roundabout.

Intersection Sight Distance Based on Critical Gap at Unsignalized Intersections (임계간격을 이용한 비신호 교차로의 시거 산정에 관한 연구)

  • 이슬기;이용재;김석근
    • Journal of Korean Society of Transportation
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    • v.21 no.5
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    • pp.97-110
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    • 2003
  • The sight distance at unsignalized intersections is the one of the fundamental geometric design elements, and can ensure safety and efficient operations. Despite its importance, little research attention has been directed in Korea compared to developed countries such as European countries, the United States, and Japan. AASHTO ISD policies have been applied to the intersection design in Korea without any revise, which can produce unrealistic and unadoptable design values. Those values are emerged from several reasons because the AASHTO ISD has been calibrated based on the local data. Therefore the ISD hardly takes into account the local characteristics of Korea such as driving behavior. vehicular movement and roadway conditions. The objective of this study is to calculate the appropriate ISD values for unsignalized intersections in the urban area in Korea. In this study, we employed the ISD model of AASHTO(2001), which is based on gap acceptance theory and can account for and take the driving and roadway conditions in Korea into consideration. The approach can also consider the complex driving maneuvers at the intersections in a proper and simple manner. The results in this study show that the ISD design criteria currently used in Korea are more conservative(safer) than those of the USA. In other words, the ISD using field data collected in this study has generally smaller values than those in USA.

A Study on the Factors Affecting the Implementation Process of Information System Development Methodology (시스템 개발방법론의 구현 프로세스에 미치는 영향요인에 관한 연구)

  • 장윤희;이재범
    • Korean Management Science Review
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    • v.19 no.1
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    • pp.197-224
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    • 2002
  • Our study focuses on the implementation of IS development methodology as the innovation of IS organization. We have two main research objectives. We Intend to understand the critical factors affecting the implementation process of IS methodology. We also intend to deeply analyze the relationship among the implementation processes of methodology. The whole innovation process is divided into detailed four levels tilth dynamic and evolving Point of clew a cognition level, an adoption level, an acceptance level and an usage level. The results of our study are as follows. The main factors affecting initiation level of the IS methodology are the innovativeness of IS members, the existence of champion manager, training, the existence of IS performance gap, executive supports for IS organization, and the relative advantage of IS development methodology At the Implementation level, It is understood that the existence of champion manager executive supports, training and the relative advantage of innovation are the main factors. However, the complexity of Innovation is a megative factor about the quality of accepting and using the methodology In Innovation process. In performing the Innovation process, the Previous level gives very notable affection to the continuous next level. However it's also understood that positive attitude of adoption level does not directly affect the quality of using Innovation. Therefore, IS managers must pay attention to manacle each level of the Innovation Process to successfully accomplish the Implementation of IS methodology.

Some Considerations for the Fire Safe Design of Tall Buildings

  • Cowlard, Adam;Bittern, Adam;Abecassis-Empis, Cecilia;Torero, Jose L.
    • International Journal of High-Rise Buildings
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    • v.2 no.1
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    • pp.63-77
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    • 2013
  • In any subject area related to the provision of safety, failure is typically the most effective mechanism for evoking rapid reform and an introspective assessment of the accepted operating methods and standards within a professional body. In the realm of tall buildings the most notable failures in history, those of the WTC towers, widely accepted as fire induced failures, have not to any significant extent affected the way they are designed with respect to fire safety. This is clearly reflected in the surge in numbers of Tall Buildings being constructed since 2001. The combination of the magnitude and time-scale of the WTC investigation coupled with the absence of meaningful guidance resulting from it strongly hints at the outdatedness of current fire engineering practice as a discipline in the context of such advanced infrastructure. This is further reflected in the continual shift from prescriptive to performance based design in many parts of the world demonstrating an ever growing acceptance that these buildings are beyond the realm of applicability of prescriptive guidance. In order for true performance based engineering to occur however, specific performance goals need to be established for these structures. This work seeks to highlight the critical elements of a fire safety strategy for tall buildings and thus attempt to highlight some specific global performance objectives. A survey of tall building fire investigations is conducted in order to assess the effectiveness of current designs in meeting these objectives, and the current state-of-the-art of fire safety design guidance for tall structures is also analysed on these terms. The correct definition of the design fire for open plan compartments is identified as the critical knowledge gap that must be addressed in order to achieve tall building performance objectives and to provide truly innovative, robust fire safety for these unique structures.

Trust to Share: Investigating the Key Factors to Influence Tenants' Participation in Online Short-Term Rent

  • Liuye Yu;Zhixia Zang;Xue Yang
    • Asia pacific journal of information systems
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    • v.29 no.2
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    • pp.308-327
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    • 2019
  • The concept of sharing economy has received rich attention in recent years. As a typical type of business model in the sharing economy, online short rent has been paid attention by both industry and academia. In this study, we find trust to be a critical determinant to the success of online short rent platforms. Based on three dimensions of trust theory, i.e., ability, benevolence and integrity, we investigate the factors influencing tenant' willingness to participate in online short rent. We further examine the extent to which trust can influence the number of sales and comments of rooms listed at online short-term rent platforms, which can represent tenant' willingness to participate in the sharing economy. The results show that the trust dimensions represented by a landlord's personal characteristics have significant positive correlations with the number of sales and comments. For example, the real name authentication and the sesame score can represent the trust integrity; online replay ratio and the average confirmation time representing the trust sincerity, and the order acceptance ratio representing the trust ability. On this basis, we proposed some recommendations for both platforms and landlords. For example, the landlords can improve the tenants' trust by authenticating his/her real name, replying actively and timely. For platforms, when they make housing list ranking rules, they can take the landlord's personal attributes that may affect trust into consideration. Moreover, platforms can also allow landlords to supply value-added services to improve service quality and ultimately promote the virtuous circle of the platform ecosphere. Through conducting the empirical research on a particular application of the sharing economy, we aim to fill the research gap of this field in China and provide theoretical and practical contributions to the future development of online short rent.

A Study on EC Acceptance of Virtual Community Users (가상 공동체 사용자의 전자상거래 수용에 대한 연구)

  • Lee, Hyoung-Yong;Ahn, Hyun-Chul
    • Asia pacific journal of information systems
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    • v.19 no.1
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    • pp.147-165
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    • 2009
  • Virtual community(VC) will increasingly be organized as commercial enterprises, with the objective of earning an attractive financial return by providing members with valuable resources and environment. For example, Cyworld.com in Korea uses several community services to enable customers of Cyworld to take control of their own value as potential purchasers of products and services. Although initial adoption is important for online network service success, it does not necessarily result in the desired managerial performance unless the initial usage is continuously related to the continuous usage and purchase. Particularly, the customer who receives relevant online services and is well equipped with online network services, will trust the online service provider and perceive less risk and experience more activities such as continuous usage and purchase. Thus, how to promote continued online service usage or, alternatively, how to prevent discontinuance is a critical issue for VC service providers to consider. By aggregating a wide range of information and online environments for customers and providing trust to its members, the service providers of virtual communities help to reduce the perceived risk of continuous usage and purchase. Drill down, online service managers realize that achieving strong and sustained customers who continuously use online service and purchase on it is crucial. Therefore, the research into this online service continuance will identify the relationship between the initial usage and the continuous usage and purchase. The research of continuous usage or post adoption has recently emerged as an important issue in the IS literature. Individuals' information systems(IS) continuous usage decisions are congruent with consumers' repeat purchase decisions. The TAM(Technology Acceptance Model) paradigm has been strongly confirmed across a wide range from product purchase on EC to online service usage contexts. The analysis of IS usage based on TAM has proven to be successful across almost online service contexts. However, most of previous studies have focused on only an area (i.e., VC or EC). Just little research has tried to analyze the relationship between VC and EC. The effect of some factors on user intention, captured through several theories such as TAM, has been demonstrated. Yet, few studies have explored the salient relationships of VC users' EC acceptance. To fill this gap between VC and EC research, this paper attempts to develop a research model that extends the TAM perspective in view of the additional contributions of trust in the service provider and trust in members on some factors that affect EC and VC adoption. In this extension, we applied the TAM-to-TAM(T2T) model, and analyzed the transfer effect of trust between these two TAMs. The research model was empirically tested on the context of a social network service. The model was to extend TAM with the trust concept for the virtual community environment from the perspective of tasks. By building an extended model of TAM and examining the relationships between trust and the existing variables of TAM, it is aimed to explain a user's continuous intention to use VC and purchase on EC. The unit of analysis in this paper is an individual user of a virtual community. The population of interest is the individual with the experiences in virtual community. The data for this paper was made available via a Web survey of VC users. In total, 281 cases were gathered for about one week, but there were some missing values in the sample and there were some inappropriate cases. Thus, only 248 cases were finally analyzed. We chose the structural equation analysis to test the hypotheses and it is better suited for explaining complex relationships than the other methods. In this test, AMOS was used to test the Structural Equation Model (SEM). Noticeable results have been found in the T2T model regarding the factors affecting the intention to use of virtual community and loyalty. Our result showed that trust transfer plays a key role in forming the two adoption beliefs. Overall, this study preliminarily confirms the salience of trust transfer in online service.

About the Multi-layered Communication of Princess Pari on the Webtoon Platform of Daum -Focusing on Analysis of Narrative Structure and Comments (Daum 웹툰 <바리공주>를 통해 본 고전 기반 웹툰 콘텐츠의 다층적 대화 양상 -서사구조와 댓글 분석을 중심으로)

  • Choe, Key-Sook
    • Journal of Popular Narrative
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    • v.25 no.3
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    • pp.303-345
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    • 2019
  • This article analyzes the multi-layered communication in the Webtoon Princess Pari, released on the Daum portal site, created (written and illustrated) by Kim Naim, through analyzing the narrative structure and comments with the qualitative / quantitative methodology. The webtoon Princess Pari is structured in an omnibus style in which unit narratives are intermittently articulated, multi-lined, and interconnected. As integrated narratives which link with unitary narratives, Pari's growth story as a shaman and a romance narrative are structured. The classical original story of the shaman was used as a prehistory corresponding to the prequel of the webtoon through a preview, and the writer restructured the narrative to overcome the contradictions of the gender asymmetry and the patriarchal ideology of the original text. The viewer then creates a conversational space by giving critical and reflective comments. According to a statistical analysis conducted through sampling, the types of comments can be classified as follows: Appreciation and criticism of the contents ≫ Emotional response ≫ Intuitive overall review ≫ Knowledge and reflection ≫ Comments on comments. In the process of creation and acceptance of the Webtoon, a multi-layered dialogue between classical and modern, content and audience, acceptance and creation has been at play. In the creation dimension, the writer used a device to fill the gap of mythical symbols of the contents. At the level of the audience, they formed a culture of sharing information, knowledge, and reflection about tradition/folk/culture through comments. This corresponds to classical and modern dialogue through the webtoon. The viewers form a sympathetic bond, attempt hermeneutical coordination, supplement the information, and search for a balanced angle through controversial conversation. In addition, by commenting on attitudes, views, and perspective, the commentators showed a behavioral pattern corresponding to meta-criticism in literature. The viewers' comments acted as feedback on the creation of the webtoons, so that the creation and acceptance itself influenced the production of the content of the webtoon. The webtoon Princess Pari, which was based on Korean classical narrative, has been reorganized onto 'moving and dynamic' content, which leads to sense, thinking, criticism and reflection through the formation of various dialogues.