• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.4
• /
• pp.334-341
• /
• 2015

This paper develops a new system for remotely monitoring and controlling the windows and doors in mobile environment. We design and implement the opening and shutting unit, the gateway, and the control server system, respectively. The opening and shutting unit consists of the driver using DC motor and the motion controller which monitors the state and transfers the control information. The gateway supports TCP/IP and CDMA protocol, which is the interface of wire and wireless communication for transferring the current state and control information. The control server consists of the program to store and process the control information, the middleware to support the processing of various state message, and DB for monitoring the state and remotely controlling the system. Especially, an application software and the Web-based user interface have also been developed to support the mobile environment. The operation performances, environment influences, driving persistences, and operation failure ratio, which are based on PC and smart-phone, have been tested in 2 authorized agencies. The test results show that the developed system has a superior performance.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.3
• /
• pp.563-577
• /
• 2018

In order to support secure communication in VANET(Vehicular Ad hoc Network), messages exchanged between vehicles or between vehicle and infrastructure must be authenticated. In this paper, we propose a hierarchical anonymous authentication system for VANET. The proposed system model reduces the overhead of PKG, which is a problem of previous system, by generating private keys hierarchically, thereby enhancing practicality. We also propose a two-level hierarchical identity-based signature(TLHIBS) scheme without pairings so that improve efficiency. The proposed scheme protects the privacy of the vehicle by satisfying conditional privacy and supports batch verification so that efficiently verifies multiple signatures. Finally, The security of the proposed scheme is proved in the random oracle model by reducing the discrete logarithm problem(DLP) whereas the security proof of the previous ID-based signatures for VANET was incomplete.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.6 s.348
• /
• pp.9-22
• /
• 2006

When the legacy multicast routing protocols are adopted in If-based mobile core networks, there are some problems such as traffic injection from unnecessary sources, traffic overhead by group management and router performance degradation by large amount of multicast session information. In this paper, we propose a stateless multicast mechanism which has no need to maintain multicast information for session status and reduces redundant network overhead for maintaining multicast tree. In addition interworking with IGMPv3 gets rid of traffic from unnecessary sources which have no registration from receivers. The operations of essential components including a gateway node for interworking with the legacy Internet multicast network, a gateway node for transparency to radio access network and a intermediate node in mobile core networks, are definitely defined and the proposed communication architecture is completed. Finally we evaluate and approve the performance of the proposed architecture by means of well-designed network simulation.

• Journal of The Korean Association of Information Education
• /
• v.19 no.1
• /
• pp.69-76
• /
• 2015

In current information society, there is a barrier called digital divide. Due to this barrier, the disabled have difficulties to communicate with the world. Recently, with advanced smart techniques, smart devices become necessity for the disabled. Currently improvements of smart application accessibility become a great concern for the disabled. The purpose of this paper is to present some guidelines for enhancing smart application accessibility for the disabled. The enhancement guidelines are developed based on the existing mobile accessibility guidelines and modified for better adaptability for the disabled. Our principles are as follows: minimizing blue light emission from smart devices, automatic focus on input window, action trace, font color change, emergency notification by motion, gesture recognition, control location, scrolling avoidance, auditory service for visual warning, and icon literation.

• Journal of Korea Multimedia Society
• /
• v.7 no.2
• /
• pp.264-271
• /
• 2004

A load-sharing algorithm must deal with load imbalance caused by characteristics of a network and heterogeneity of nodes in Internet-based clustering systems. This paper has proposed the Efficient Load-Sharing algorithm. Efficient-Load-Sharing algorithm creates a scheduler based on the WF(Weighted Factoring) algorithm and then allocates tasks by an adaptive granularity strategy and the refined fixed granularity algorithm for better performance. In this paper, adaptive granularity strategy is that master node allocates tasks of relatively slower node to faster node and refined fixed granularity algorithm is to overlap between the time spent by slave nodes on computation and the time spent for network communication. For the simulation, the matrix multiplication using PVM is performed on the heterogeneous clustering environment which consists of two different networks. Compared to other algorithms such as Send, GSS and Weighted Factoring, the proposed algorithm results in an improvement of performance by 75%, 79% and 17%, respectively.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.47 no.6
• /
• pp.86-92
• /
• 2010

This paper proposes a new steganography scheme based on frequency domain using various image frames and collages that can protect the copyright of digital contents for users and securely perform to exchange the security information in the digital communication environments. The main idea of our proposed scheme is that the security informations related its copyright embed into the frequency domain of the image frame and collages when a user decorates the original image by using various image frames and collages. The strengths of our proposed scheme are as follows: (1) It allows to freely control the quantity of embedded information by changing the number of image frames and collages. (2) It is secure to variety image distortion attacks. (3) It maintains high PSNR(Peak Signal to Noise Ratio). As a result, the proposed steganography scheme can be used practically diverse multimedia security fields such as digital copyright protect, secure message communication and digital watermarking.

• 한국HCI학회:학술대회논문집
• /
• 2009.02a
• /
• pp.1172-1175
• /
• 2009

This study aims to develop communication devices and interfaces to address the communication needs of the hearing impaired. Through three FGI (Focused Group Interview)s with deaf persons and sign-language interpreters, we studied the communication methods, devices, and needs of the deaf. On the basis of our analysis, we propose a communication framework to improve their means of communication with normal or other deaf persons. We have designed a communication system that is based on the proposed framework: this system suggests functions for remote sign-language interpretation services for conversations in close-range and over the phone. Details are presented regarding the design of interfaces for video calls, text messages, and digital memos, addressing the conversation patterns of the deaf. The system includes hardware form factors for video phones that facilitate sign language conversations and also mitigate other auditory problems in daily life, such as problems with door bells. The design concept has been verified through a test with six deaf users.

• The KIPS Transactions:PartC
• /
• v.12C no.5 s.101
• /
• pp.741-748
• /
• 2005

SyncML is an open standard data synchronization protocol proposed by OMA(Open Mobile Alliance). In this paper, a Session Handler module, one of major modules for developing SyncML data synchronization clients, and a client User Setup program are designed and implemented. The Session Handier Module controls communication sessions, generates header parts of messages exchanged, and determines the legitimacy of incoming messages. In order to justify normal operations of the Session Handler module and the client User Setup program implemented In this paper, they are ported to a Zaurus PDA, which runs on LINUX operating system. In addition, data synchronization operations are performed between the PDA and a Synthesis sever, whose SyncML data synchronization operation is certificated by OMA, Wireless Internet International Standard Forum.

• The Journal of the Acoustical Society of Korea
• /
• v.19 no.2
• /
• pp.101-105
• /
• 2000

A telegram has been used to transmit the emergency news or celebration message. So, it has been very important media in our life. Although the telegram processing is more and more convenient, on the other hand, the telegram service contains only text message. The voice telegram is that delivering user's voice with text message. So, the voice telegram can be delivered sender's emotions and feelings. However, since voice information contains lots of data, large memory size and high cost processor are needed to deliver itself. In this paper, we proposed a new speech waveform coding method that has low complexity and low cost implementation for the voice telegram system. First, we fixed one basic speech waveform per pitch period and measured the waveform similarity between basic and neighbor speech waveform. Second, if the similarity satisfied threshold values, we compress the neighbor speech waveform with pitch and magnitude value per pitch period and if not, we save speech waveform. When the compression is about 45%, we obtained about 4 point in MOS.

• Journal of the Korea Convergence Society
• /
• v.6 no.4
• /
• pp.235-241
• /
• 2015

As the broadcast, tele communication and media technology develop, the media are divided into various specialities from the internet to the mobile device. An advertising creative in the field, an innovative changes are taking place that had not been in the era of the passed traditional media TV, newspaper, magazine and etc. It's not but the various media's dividing, also the consumers who use the media are evolving in their media behavior from a passive attitude to a positive one. In other words, They consumers receive the advertising messages with positive attitude to researching the message in the searching tool by themselves and participate, act, and diffuse their acknowledgements. In this thesis, as the advertising creative circumstance like this, these varied advertising creative are tried to explained by the three dimension module that is suggested in this thesis.