• Journal of Korean Society for Geospatial Information Science
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• v.18 no.1
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• pp.47-53
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• 2010

The correct river discharge is a important item to keep a river role of using, controlling and ecology. Especially river role of ecology is very important for environmental development of river. In assesment of ecological flow, exact information of river life and topograph is very important. In this paper, the assesment of environmental flow is conducted using geo-spatial data of basin and river. The geo-spatial data is used as a important basic data in river restoration.

• Journal of Information Technology Applications and Management
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• v.27 no.6
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• pp.31-51
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• 2020

During the last decade, social live streaming service like Periscope, Ustream, and YouNow has developed from a niche market into a mainstream activity. In this media environment, social live streaming service has a tremendous impact on the social behaviors of users. Despite the rapid development, there are a lack of studies to make better understand the media environment changes through social live streaming service. This study adopted an affordances approach that leads us to identify six distinctive social affordances (visibility, accessibility, information sharing, social interaction, role-taking, interactive revenue) for user engagement in social live streaming service. Specifically, this study explores the impact of social affordances on perceived flow, followed by user engagement including passive and active engagement. Empirical data analysis with 258 questionnaires suggests that social affordances affected users' flow perception, and flow has an effect on active as well as passive engagement. Contrary to the expectation in a hypothesized research model, only the impact of accessibility on flow was rejected.

• The Journal of Information Systems
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• v.17 no.2
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• pp.113-135
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• 2008

This study introduces the construct of social influence and combines the construct with the flow theory and TAM framework Subjective norm, image, and visibility identified as the dimensions of social influence are hypothesized to influence flow and perceived usefulness, and then the intention to use of online community. Data were collected through a survey of respondents who have the experience of using an online community, and analyzed by using structure equations modelling. The major findings of this study are as follows: First, subjective norm was found to have a positive influence on flow and intention to use. Second, image was found to have a positive effect chi flow and perceived usefulness. Third, visibility was found to have a positive influence on perceived usefulness. Finally, flow and perceived usefulness were also found to have a positive effect on the intention to use. Implications of these findings are discussed for researchers and practitioners.

• 한국가시화정보학회:학술대회논문집
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• 2005.12a
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• pp.99-102
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• 2005

This study was conducted for obtaining the optimized data to build the mixer or micro fluid device as measuring the three dimensions flow field in micro mixer. To acquire the rapid diffusion on the region of low Reynolds (Re < 100), the staggered herringbone mixer using chaotic advection was selected in this case. At first, by conducting the numerical analytical virtual experiment using CFD-ACE+, three dimensions flow field in the micro mixer was estimated As this flow field was proven using defocusing particle tracing method, the behavior of micro flow with three dimensional aspects could be analyzed. Numerical analysis and flow pattern in the micro mixer by experimental verification made to be able to analyze the chaotic advection. These can be important sources for building more optimized form. Verifying the information of three dimensional flow structure, these information can be used as the data for developing and improving the $\mu$ -TAS.

• Journal of computational fluids engineering
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• v.10 no.1
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• pp.80-86
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• 2005

In order to control the transonic flow field with a shock wave, a condensing flow was produced by an expansion of moist air on a circular bump model and shock waves were occurred in the supersonic parts of the fields. Furthermore, the additional passive technique of shock-boundary layer interaction using the porous wall with a cavity underneath was adopted in this flow field. The effects of these methods on the shock wave characteristics were investigated numerically. The result showed that the flow fields might be effectively controlled by the suitable combination between non-equilibrium condensation and the position of porous wall.

• Journal of information and communication convergence engineering
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• v.7 no.4
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• pp.539-544
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• 2009

An estimation of 3D velocity field including occluded parts without maxing tracer to the fluid had not only never been proposed but also impossible by the conventional computer vision algorithm. In this paper, we propose a new method of three dimensional optical flow of the fluid based on physical model, where some boundary conditions are given from a priori knowledge of the flow configuration. Optical flow is obtained by minimizing the mean square errors of a basic constraint and the matching error terms with visual data using Euler equations. Here, Navier-Stokes motion equations and the differences between occluded data and observable data are employed as the basic constrains. we verify the effectiveness of our proposed method by applying our algorithm to simulated data with partly artificially deleted and recovering the lacking data. Next, applying our method to the fluid of observable surface data and the knowledge of boundary conditions, we demonstrate that 3D optical flow are obtained by proposed algorithm.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.187-188
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• 2003

In order to control the transonic flow field with shock wave, a condensing flow was produced by an expansion of moist air on a circular bump model and shock waves were occurred in the supersonic parts of the fields. Furthermore, the additional passive technique of shock - boundary layer interaction using the porous wall with a cavity underneath was adopted in this flow field. The effects of these methods on the shock wave characteristics were investigated numerically. The result showed that the flow fields might be effectively controlled by the suitable combination between non-equilibrium condensation and the position of porous wall.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.149-150
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• 2019

기존의 Flow 규칙 구분을 위해 연구되었던 기법들은 적응적 또는 사전 처리의 접근법이 제안되었으나 각각의 장단점을 기반으로 효율적인 접근법이 연구되어야한다. 본 연구에서는 Flow 규칙을 삽입하기 전에, 스위치의 계산 작업을 완화하기 위하여 전이 학습 기법인 TrAdaBoost를 이용함으로써 Flow 규칙들을 구분하는 접근법을 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.4887-4907
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• 2017

Accurate traffic flow forecasting is critical to the development and implementation of city intelligent transportation systems. Therefore, it is one of the most important components in the research of urban traffic scheduling. However, traffic flow forecasting involves a rather complex nonlinear data pattern, particularly during workday peak periods, and a lot of research has shown that traffic flow data reveals a seasonal trend. This paper proposes a new traffic flow forecasting model that combines seasonal relevance vector regression with the hybrid chaotic simulated annealing method (SRVRCSA). Additionally, a numerical example of traffic flow data from The Transportation Data Research Laboratory is used to elucidate the forecasting performance of the proposed SRVRCSA model. The forecasting results indicate that the proposed model yields more accurate forecasting results than the seasonal auto regressive integrated moving average (SARIMA), the double seasonal Holt-Winters exponential smoothing (DSHWES), and the relevance vector regression with hybrid Chaotic Simulated Annealing method (RVRCSA) models. The forecasting performance of RVRCSA with different kernel functions is also studied.

• Korean Management Science Review
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• v.23 no.2
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• pp.41-57
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• 2006

The purposes of this research are to identify causalities among flow and customer loyalty In Chinese online games, and to identify the factors by which flow are influenced. This research tests the model with Chinese on-line game users and compare this result with Korea and Japanese results which were conducted by Lee's research. These implications are thought to be helpful for Korean online game companies to understand the Chinese online game user and to develop the penetration strategies. The results indicated that significant Path coefficients to flow were the convenience of operator, the provision of information, the reality of design. The results indicated that significant path coefficients to customer loyalty were the involvement of virtual community and flow. The involvement of virtual community to flow was not significant but to customer loyalty was significant. The provision of information was negatively influenced on flow. The result of comparison indicated that the path coefficients were different among nations. Korea online game companies need to develop the indigenized online game and to Provide the information to their Chinese partner correctly and quickly.