• Journal of KIISE:Information Networking
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• v.35 no.6
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• pp.510-520
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• 2008

These days, the network convergence for utilizing heterogeneous network on mobile device is being very actively studied. However, understanding characteristics of physical network interfaces and video encoder is needed for using the network convergence technologies efficiently. Thus, this paper proposes an optimized method for streaming video data through different network paths depending on data characteristics and channel condition. Accordingly, unlike the traditional methods, this study divides scalable coded videos by layer importance, the importance of stream information, and the importance in consideration of video decoder's robustness and selectively sends the data via multiple channels. And the experimental results show over 1dB increment in PSNR. The result of this study will provide an optimized video transmission technique in the next generation network convergence environment in which mobile devices have multiple network interfaces.

• The KIPS Transactions:PartC
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• v.14C no.2
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• pp.171-178
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• 2007

In mobile ad hoc networks, an application scenario requires mostly group mobility behavior in the mix of group moving nodes and individually moving nodes. The nodes of those applications tend to belong to the movement group with similar movement behavior. Group mobility is one of the good methods to improve scalability, and reduces the protocol overhead. In this paper, we propose the multicast architecture which regards nodes that have equal group mobility in the heterogeneous group mobility network as the single entity with the multiple interfaces and composes multicast tree, The logical cooperative entity-based multicast architecture accommodates the scalability, the multicast tree simplification, and the protocol overhead reduction which arc obtained from the hierarchical multicast architecture, while it maintains the nat multicast architecture for the data transmission. It also prevents the concentration of the energy consumption dispersing data forwarding load into the several ingress/egress nodes. Results obtained through simulations show that logical cooperative entity based multicast protocol with multiple interfaces offers the protocol scalability and the efficient data transmission.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.79-87
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• 2010

This paper proposes a L3 handover method to minimize packet loss for supporting service continuity to IMS Terminal which has a single WLAN interface. The existing IMS based handover solution is able to support handover between different access networks in case that a terminal has multiple interfaces. That is, WLAN terminals need multiple interfaces to connect with one or more access networks. This proposed method configures IP address for the terminal in target WLAN previously by using Candidate Access Router Discovery(CARD) mechanism. Also, in the proposed method, service continuity server performs L3 connection establishment in target WLAN and registration to IMS server instead of the terminal. And then session control mechanism based on SIP is performed to support service continuity. We analyzed handover latency and signaling cost in the proposed method and existing method to show the improved performance by the proposed method.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.71-80
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• 2014

Recently, most mobile nodes, such as smartphones, will have multiple wireless radio interfaces. This feature allows a mobile node to access a multi-network through multiple wireless radio interfaces simultaneously. Accordingly, various networking technology has been studied to use wireless multi-interface more efficiently. In this paper, MPTCP based handover scheme is proposed to reduce data loss and end-to-end latency during the handover in PMIPv6 domain. The proposed scheme performs 2-step flow mobility on the multi-path established through the multi-interface of mobile node in the handover procedure and uses MPTCP subflow function to overcome end-to-end disconnection during the handover. Therefore, the proposed scheme takes the advantage of being able to minimize data loss and a latency generated during performing the handover of mobile node.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1901-1907
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• 2015

Today's smartphones and user devices are equipped with multiple radio interfaces increasingly. Aggregating theses multiple radio interfaces and using them concurrently will increase a user's communication speed immediately, but at the expense of increased power consumption. In this paper, we develop a mathematical performance model of an adaptive radio activation scheme by which a radio interface is activated only when needed for performance increase and deactivated otherwise. The developed model shows that the adaptive scheme reduces delay significantly and almost halves power consumption below a certain level of traffic input.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.230-230
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• 2013

In amorphous or microcrystalline thin-film silicon solar cells, p-i-n structure is used instead of p/n junction structure as in wafer-based Si solar cells. Hence, these p-i-n structured solar cells inevitably consist of many interfaces and the cell efficiency critically depends on the effective control of these interfaces. In this study, in-situ plasma treatment process of the interfaces was developed to improve the efficiency of a-Si:H solar cell. The p-i-n cell was deposited using a single-chamber VHF-PECVD system, which was driven by a pulsed-RF generator at 80 MHz. In order to solve the cross-contamination problem of p-i layer, high RF power was applied without supplying SiH4 gas after p-layer deposition, which effectively cleaned B contamination inside chamber wall from p-layer deposition. In addition to the p-i interface control, various interface control techniques such as thin layer of TiO2 deposition to prevent H2 plasma reduction of FTO layer, multiple applications of thin i-layer deposition and H2 plasma treatment, H2 plasma treatment of i-layer prior to n-layer deposition, etc. were developed. In order to reduce the reflection at the air-glass interface, anti-reflective SiO2 coating was also adopted. The initial solar cell efficiency over 11% could be achieved for test cell area of 0.2 $cm^2$.

• Journal of Korea Multimedia Society
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• v.8 no.11
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• pp.1483-1495
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• 2005

TCP/IP is the most commonly used protocol to communicate among servers, and is used in a wide range of applications. Unfortunately, Data transmission through TCP/IP places a very heavy burden on host CPUs. And it hardly makes another job to be processed. So, TOE(TCP/IP Offload Engine) is considered in many servers. But, most of TOE modules tends to not support binary compatibility for standard socket interfaces. So, it has problems that existing applications should be modified and recompiled to get advantage of TOE device. In this paper, to resolve upper problems, we suppose design and implementation of TOE module supporting binary compatibility for standard socket interfaces. Also, it can make a usage of multiple TOEs and NICs simultaneously.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.179-186
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• 2012

Nowadays, the multihomed host equipped with multiple network interfaces has been interested research in next generation wireless network, because the mobile users expect that they can be able to access services not only anywhere, at any time and from any network but also simultaneously. This paper addresses the mobility simulation model of the multihomed node for supporting MIPv4 and MIPv6 function in an interworking of Worldwide Interoperability for Microwave Access (WiMAX) and IEEE 802.11 WLAN. The multihomed node with two air interfaces has been developed based on WiMAX and WLAN workstation node model in simulation software. The main point of the developed model is to support both MIPv4 and MIPv6 function, and provide network selection policy for the multihomed node between WiMAX and WLAN network. Based on the received Router Advertisement along with the interface number, we can manage the access interfaces in ordered list to make handover decision while the multihomed node is moving. In the end of this paper, the simulation scenarios and results are shown for testing MIPv4 and MIPv6 function.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.173-180
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• 2003

In spite of its potential importance in the assessment of geosynthetic-related dynamic problems, no serious attempt has yet been made to investigate a probable dependence of dynamic friction resistance of the geosynthetic interface on shear displacement rate. Hence, an experimental study of geosynthetics was carried out on a shaking table, and the relationship between dynamic friction resistance and shear displacement rate of geosynthetic interfaces was investigated. A cyclic, displacement rate-controlled experimental setup was used. The subsequent multiple rate tests showed that interfaces that involve geotextiles have such unique shearing characteristics that shear strengths tend to increase with displacement rate. In contrast, once submerged with water, the shear strength appears to be no longer dependent on the displacement rate, partly due to lubrication effect of water trapped inside the interface. The results of the experimental study can be used in the seismic safety assessment of a landfill cover and slope where the geosynthetic materials are exposed to a relatively low normal stress.

• BMB Reports
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• v.53 no.2
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• pp.74-81
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• 2020

Under physiological and pathological conditions, mechanical forces generated from cells themselves or transmitted from extracellular matrix (ECM) through focal adhesions (FAs) and adherens junctions (AJs) are known to play a significant role in regulating various cell behaviors. Substantial progresses have been made in the field of mechanobiology towards novel methods to understand how cells are able to sense and adapt to these mechanical forces over the years. To address these issues, this review will discuss recent advancements of traction force microscopy (TFM), intracellular force microscopy (IFM), and monolayer stress microscopy (MSM) to measure multiple aspects of cellular forces exerted by cells at cell-ECM and cell-cell junctional intracellular interfaces. We will also highlight how these methods can elucidate the roles of mechanical forces at interfaces of cell-cell/cell-ECM in regulating various cellular functions.