• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.1289-1292
• /
• 1998

HCI(human computer interface) technologies have been often implemented using mouse, keyboard and joystick. Because mouse and keyboard are used only in limited situation, More natural HCI methods such as speech based method and gesture based method recently attract wide attention. In this paper, we present multi-modal input system to control Windows system for practical use of multi-media computer. Our multi-modal input system consists of three parts. First one is virtual-hand mouse part. This part is to replace mouse control with a set of gestures. Second one is Windows control system using speech recognition. Third one is Windows control system using gesture recognition. We introduce neural network and HMM methods to recognize speeches and gestures. The results of three parts interface directly to CPU and through Windows.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2015.07a
• /
• pp.55-56
• /
• 2015

본 논문에서는 여러 접속 인터페이스를 가진 노드로 구성된 저전력 손실 네트워크 기반의 로컬 Infra IoT 환경에서 로컬 Infra-less IoT 서비스를 제공하기 위한 네트워크 구성 방법을 제안한다. 우선, Infra IoT 네트워크환경의 분석을 통해 문제점을 정의하고 이후 로컬 Infra-less IoT 네트워크 모델을 정의하고 정의된 네트워크 모델에 필요한 네트워크 구성 방법을 제안한다.

• KIPS Transactions on Computer and Communication Systems
• /
• v.5 no.3
• /
• pp.55-70
• /
• 2016

The most critical research issue in MANET environment is on supporting reliable communication between various devices. Various Multi-Hop Routing Protocol studies have proceeded. However, some problems you might have found when you use the existing link state routing technique are that it increases Control Message Overhead and it is unstable when node moves in CR circumstance which has transformation of using channel and MIMC circumstance which uses a number of interfaces. This essay offers a technique which is based on On-Demand Hello and the other technique which used Broadcast Interface of optimization as a solution to decrease Control Message Overhead. Also it proposes Quick Route Restoration technique which is utilized by GPS and MPR Selection technique which consider mobility as a solution of stable communication when node moves. Those offered Routing Protocol and OPNET based simulator result will be expected to be an excellent comparison in related research fields.

• The KIPS Transactions:PartC
• /
• v.15C no.2
• /
• pp.93-102
• /
• 2008

The network weather map and bandwidth time-series graph are popularly used to understand the current and past traffic condition of NSP, ISP, and enterprise networks. These systems collect traffic performance data from a SNMP agent running on the network devices such as routers and switches, store the gathered information into a DB, and display the network performance status in the form of a time-series graph or a network weather map using Web user interface. Most of current enterprise networks are constructed in the form of a hierarchical tree-like structure with multi-Gbps Ethernet links, which is quietly different from the national or world-wide backbone network structure. This paper focuses on the network weather map for current enterprise network. We start with the considering points in developing a network weather map system suitable for enterprise network. Based on these considerings, this paper proposes the best way of using SNMP in constructing a network weather map system. To prove our idea, we designed and developed a network weather map system for our campus network, which is also described in detail.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.10B
• /
• pp.1168-1174
• /
• 2011

The IEFT has recently considered to provide flow mobility for multi-interface MN in the PMIPv6. In this paper, we proposed an extended BCE of the LMA and a novel mechanism for flow mobility of PMIPv6. With our proposal BCE and mechanism, the LMA can route packets by the flow label and hence packet loss during handover can be eliminated. Also, to validate our flow mobility scheme, we designed and implemented the PMIPv6 packet data unit and database of both LMA and MAG, and configured a testbed for flow mobility in PMIPv6. And the support of flow mobility was configured with the network connectivity test in our testbed. According to the Wireshark results, we can see that our proposed scheme works wells for flow mobility in PMIPv6.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.44 no.10
• /
• pp.110-118
• /
• 2007

In multi-hop wireless network, multi-channel makes it possible to enhance network performance because it reduces channel interferences md contentions. Recently several schemes have been proposed in the literatures to use multi-channel. Especially, MCR(Multi channel routing protocol), which utilize hybrid interface assignment, is a prominent routing protocol. MCR uses simple way to change channel but efficiently reduce channel interferences. In this paper, we propose a load-aware channel selection algorithm called LCS that enhances the channel switching algerian used in MCR protocol. In LCS, channel of a node is assigned based on collected information about queue length of neighbors. Moreover this paper evaluates the performance of in by using simulation test and testbed demonstration. Test results show that the MCR with LCS outperforms the naive MCR.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.10
• /
• pp.1999-2007
• /
• 2017

In this paper, we implement a multi-band network selection (MNS) system based on Linux operating system which determines the optimal communication link for given network conditions among the available LTE, very high frequency (VHF), and high frequency (HF). The implemented software consists of a network interface, an MNS server, and a user GUI. We perform indoor test to verify the function of the implemented MNS system using two sets of MNS system. To this end, two types of VHF communication links that follow ITU-R M.1842-1 Annex 1 and Annex 4 are emulated in software. In addition, the HF transmission (reception) port of one MNS is directly connected to the HF reception (transmission) port of another MNS. We demonstrate through indoor tests that the implemented MNS system can support seamless maritime communication service in spite of artificial disconnection or re-connection of LTE, VHFs, and HF. The implemented MNS system is applicable to various maritime communication services including e-navigation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.8
• /
• pp.2033-2042
• /
• 1996

In this papre, we describe a recently implemented echo canceller for digital cellular communication of Code Division Multiple Access(CDMA) that features time sharing of digital signal processor(DSP) over four channels in one DSP to reduce per channel costs. In the Public Land Mobile Network(PLMN), it is important to cancel the echo reflected from the Public Switched Telephone Network(PSTN) side. In case of digital mobile system, the round-trip delay of the echo is in excess of about 180 milliseconds due to frame-by-frame voice coding. It is necessary to cancel the echo in PLMN. We have developed a multi-channel echo canceller tht operates with Time Switch Module in a Mobile Switching Center(MSC). The general echo canceller needs PCM trunk interface circuits and the tone detection and disabling circuits, but the multi-channel echo canceller linked with Time Switch Module does not need them. Therefore we could develop the effective and economical echo canceller.

• Proceedings of the Korean Information Science Society Conference
• /
• 2010.06a
• /
• pp.224-225
• /
• 2010

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