• Journal of Information Processing Systems
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• 제8권4호
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• pp.603-620
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• 2012

Proxy Mobile IPv6 (PMIPv6) is a network-based mobility support protocol and it does not require Mobile Nodes (MNs) to be involved in the mobility support signaling. In the case when multiple interfaces are active in an MN simultaneously, each data flow can be dynamically allocated to and redirected between different access networks to adapt to the dynamically changing network status and to balance the workload. Such a flow redistribution control is called "flow mobility". In the existing PMIPv6-based flow mobility support, although the MN's logical interface can solve the well-known problems of flow mobility in a heterogeneous network, some missing procedures, such as an MN-derived flow handover, make PMIPv6-based flow mobility incomplete. In this paper, an enhanced flow mobility support is proposed for actualizing the flow mobility support in PMIPv6. The proposed scheme is also based on the MN's logical interface, which hides the physical interfaces from the network layer and above. As new functional modules, the flow interface manager is placed at the MN's logical interface and the flow binding manager in the Local Mobility Anchor (LMA) is paired with the MN's flow interface manager. They manage the flow bindings, and select the proper access technology to send packets. In this paper, we provide the complete flow mobility procedures which begin with the following three different triggering cases: the MN's new connection/disconnection, the LMA's decision, and the MN's request. Simulation using the ns-3 network simulator is performed to verify the proposed procedures and we show the network throughput variation caused by the network offload using the proposed procedures.

• 예술인문사회 융합 멀티미디어 논문지
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• 제6권3호
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• pp.41-49
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• 2016

본 논문에서는 현재 전 세계적으로 많은 관심이 집중되어있고, 많은 연구와 개발이 진행되고 있는 사물인터넷 시스템을 개발하였는데, 다양한 표준화 단체들 중에서 가장 많은 연구가 진행된 oneM2M 통신 프로토콜을 사용하였다. oneM2M 통신 프로토콜을 기반으로 하는 본 연구의 사물인터넷 시스템은 크게 ADN-AE 모듈과 CSE 모듈로 나눌 수 있다. AE 모듈은 다양한 서비스의 어플리케이션을 제공하거나 CSE를 관리할 수도 있다. CSE 모듈은 사물인터넷의 다양한 AE들에게 공통적으로 제공해야하는 서비스 기능들로 이루어진 플랫폼이다. CSE 모듈은 Network Manager, Message Handler, Resource Manager 모듈 등으로 구성된다. Network Manager 모듈은 oneM2M 기반 통신의 전반적인 관리와 시스템 전체의 흐름을 관장한다. Message Handler 모듈은 송수신한 모든 메시지들의 관리 및 분석을 담당하고, Resource Manager 모듈은 리소스 트리에 관한 모든 관리를 담당하도록 하였다. 리소스 트리는 관리되어야 할 오브젝트에 관한 정보를 저장한다. 각 모듈에서의 자료 흐름 및 프로토콜 매핑 등에 관해서도 설명하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제33권5호
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• pp.679-685
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• 2009

In order to simulate a smoke or poisonous gas emergency in a rectangular tunnel and to investigate a better way to exhaust the smoke, the characteristics of smoke flow have been analyzed using flow field data acquired by Particle Image Velocimetry(PIV). Olive oil has been used as tracer particles with the kinematic viscosity of air, $1.51{\times}10^{-5}\;m^2/s$. The investigation has done in the range of Reynolds number of 1600 to 5333 due to the inlet velocities of 0.3 m/s to 1 m/s respectively. The average velocity vector and instantaneous kinematic energy fields with respect to the three different Reynolds numbers are comparatively discussed by the Flow Manager. In general, the smoke flow becomes more disorderly and turbulent with the increase of Reynolds number. Kinematic energy in the measured region increases with the increase of Reynolds number while decreasing at the leeward direction about the outlet region.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2012년도 한국컴퓨터종합학술대회논문집 Vol.39 No.1(D)
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• pp.418-420
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• 2012

정보화 사회로 발전하고 네트워크가 큰 폭으로 발전함에 따라 사회에 대한 네트워크의 의존도가 커져 가고 있다. 그러나 네트워크가 발전할수록 미래의 다양한 사용자 요구사항 및 새로운 네트워크의 한계성이 나타나고 있다. 이러한 문제를 해결하기 위한 방안 중 하나로 OpenFlow기법이 제안되었다. 본 논문에서는 이러한 OpenFlow기반의 네트워크를 관리하기 위해 VN Manager(Virtual Network Manager)와 이를 활용한 경로 관리 프로그램을 구현하였다. 또한 경로 생성시 QoS를 보장하기 위해 Admission Control이 가능하도록 하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제34권6호
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• pp.825-832
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• 2010

The objective of this study is to investigate flow behaviors of polluted air in order to prevent the impact of disaster in a tunnel. This paper presents the experimental results qualitatively in terms of flow characteristics in two kinds of rectangular tunnel models in which each distance from the centerline above the inlet vent to the exhaust vent is 0 and 60 mm, respectively. The olive oil is used as the tracer particles. The flow is tested at the flow rate of $14.16{\times}10^{-4}\;m^3/s$ and the inlet vent velocity of 1.1 m/s with the kinematic viscosity of air. The aspect ratio of the model test section is 10. The average velocity vectors, streamlines, and vorticity distributions are measured and analyzed by the Flow Manager in a particle image velocimetry(PIV) system. The PIV technology gives three different velocity distributions according to observational points of view for understanding the polluted air flow characteristics. The maximum value of mean velocity generally occurs in the inlet and outlet vent regions in the tunnel models.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2000년도 추계학술대회 논문집
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• pp.174-179
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• 2000

Proposed in the paper is a V-FMS (Virtual Flexible Manufacturing System) model to be used as a prototyping tool for FMS design. The proposed V-FMS framework follows an object-oriented modeling (OOM) paradigm and is based on a set of user requirements for FMS prototyping. The V-FMS model consists of four types of object: virtual device, transfer handler, state manager and flow controller. A virtual device model, which corresponds to a static model in OOM, consists of two parts, shell and core, for reusability. A transfer handler corresponds to a functional model of OOM and it stores low level device commands required to perform job flow operations between giving and taking devices. The state manager and the flow controller constitute a dynamic model of OOM. The proposed V-FMS model has been implemented for a couple of linear type FMS-lines

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.865-867
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• 2014

IoT(Internet Of Things) 사업의 일종인 Machine Socialization은 각 기기가 지능을 가지고 M2M(Machine to Machine) 협업을 통하여 사용자의 상황을 인지하고 시나리오를 풀어나가는 것을 의미한다. 기존의 IoT는 단순한 센서 데이터를 통하여 1상황 1제어로 진행되었지만 Machine Socialization은 상황을 시나리오대로 풀어나가고 Machine Manager가 전체적 흐름을 통제하고 제어하는 것을 의미한다. 본 논문에서는 기존 H2H(Human to Human)의 SNS(Social Network Service)을 M2M에 적용하기 위한 스키마 제안하고 Machine Manager가 시나리오를 풀어나가야 하기 위한 각 기기의 정보를 스키마로 제안한다.

• Journal of Advanced Marine Engineering and Technology
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• 제32권6호
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• pp.886-892
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• 2008

The development of fluid mechanics is briefly reviewed and the importance of fluid flows to heat and mass transfer in nature as well as to science and engineering is outlined. This paper presents the experimental results of air flow in the rectangular tunnel which has four different exhaust outlets, each distance of which from the inlet is 0, 30, 60 and 90mm respectively. This experiment is conducted by using the olive oil as the tracer particles and the kinematic viscosity of the air flow is $1.51{\times}10^{-5}\;m^2$/s. The flow is tested at the flow rate of 1.3 $m^3$/h and the velocity of 0.3 m/s. PIV technology can be used to make a good description of the smoke flow characteristics in the tunnel.

• Journal of Advanced Marine Engineering and Technology
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• 제35권5호
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• pp.608-615
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• 2011

The objective of this study is to investigate the flow characteristics of polluted air behavior in rectangular tunnels using a PIV system and a commercial CFD program. The PIV experiments are simulated by using the olive oil as the tracer particles in scaled rectangular tunnels. Each model has one of four different outlet vents, each dimensionless L/H ratio of which is 0, 0.375, 0.75 and 1.125, respectively as the locations of each outlet are away from the vertical centerline through the inlet. A commercial CFD program, ANSYS CFX, was used to examine the velocity fields and the pressure distributions in numerical simulations. The kinematic viscosity of the air flow of $1.51{\times}10^{-5}m^2/s$ and the flow velocity of 0.3 m/s at the inlet are given under the same conditions in order to analyze the polluted air flow characteristics experimentally and computationally. This study is considered to examine the effect of the outlet locations in the naturally ventilated tunnel models.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.303-305
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• 2012

This paper presents a system called a Cash-flow based Construction Scheduling Optimization (CfSO). The existing CPM is biased on schedule and cost management. For a profitable and successful project management, the cash-flow which occurred actually by contractual conditions should be considered in the project scheduling. Therefore, this study provides a method to estimate the amount of a cash-flow occurred periodically by integrating the terms of contract into scheduling. The proposed methodology is implemented as a system prototype in Microsoft Excel. CfSO helps a site manager as a decision-maker to establish a optimized project scheduling and decide profitable contractual conditions against a construction owner.