• Journal of the Korea Society of Computer and Information
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• v.14 no.2
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• pp.91-101
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• 2009

MMS (Multimedia Messaging Services) is one of the most basic services of mobile communication as well as a promising m-commerce enabling service. In our study, we hypothesize that the personality-based and cognitive traits of TAM and social cognitive theory are antecedents to MMS acceptance asking: what are the key determinants of intention to use MMS? An empirical investigation of 1,016 mobile phone users in South Korea was conducted. PLS results provided support for the effects of self-efficacy, perceived ease of use, relative advantage, credibility on attitude toward MMS use and strong support for the effect of attitude toward intention to use MMS. Our results provided a detailed account of the key forces underlying users intention to use MMS including personal and cognitive trait measures. Theoretical and practical implications of these findings are discussed in the paper.

• Journal of the Ergonomics Society of Korea
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• v.26 no.4
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• pp.65-73
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• 2007

This study evaluated the short message service (SMS) and multimedia message service (MMS) usability of mobile phones and wireless internet services by performance failure rates and flowcharts that adopted the concept of state diagrams. Forty-eight participants who had an experience of using mobile phones were recruited by posting an advertisement on websites for the experiment. They carried out both SMS and MMS tasks with the mobile phones of LG Cyon and Samsung Anycall as well as the wireless internet services of LGT ez-i, KTF magicN, and SKT NATE. In general, Cyon had the lower performance failure rate than Anycall for SMS, and ez-i had the lowest performance failure rate than the other services for MMS. More specifically through the workflow analysis, most participants used hot keys to take 7-8 steps to send a SMS including a symbol and had a difficulty in typing the symbol. They also took 10-11 steps to send a MMS after taking and attaching two pictures. Anycall, magicN, and NATE had significantly large error and failure rates due to the limited option of the menu paths that users could take and poor compatibilities of menu names and between menu and navigation keys. This study showed the possibility of use of flowcharts for systematic and specific usability evaluation methods and found the causes of performance errors and failures with mobile phones and wireless internet services to provide insight into their design.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.51-56
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• 2011

Recently, it is emerging in computing industry related ubiquitous. Also U-Healthcare system develops rapidly based on this trends. It is required system of health-status information to check user's health information on real-time and wireless network environment. Consequently, in this paper propose a health-Information system based on wireless and real-time environment. It can check a tremor pulse with method of photo-plethysmography. It convert pulse state information into 2-dimension bar code in order to confirm health information using mobile and also this system provide service of pulse visual record and explanation from specialist with MMS.

• Journal of Digital Convergence
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• v.18 no.5
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• pp.187-195
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• 2020

Although multimedia messaging services (MMS) are becoming increasingly popular, and companies are maximizing the use of their content, few systematic studies on MMSs exist. This study examined technology acceptance factors for MMS in 398 young people aged 10 to 39 to identify MMS users' continuous intention to use (CITU) via a questionnaire and SPSS21 and PLS-Graph 3.0. The results showed that perceived media richness (PMR) had a positive effect on perceived usefulness, perceived ease of use, and most importantly, CITU. Furthermore, PMR had a positive effect on perceived ease of use as a moderating effect on experience. To increase use efficiency in MMSs based on these results, media richness, perceived ease of use, perceived usefulness, and user experience may serve as important variables affecting users' CITU and provide a basic reference and development direction for MMS users. Future studies should include more variables and examine additional factors when analyzing the structural model.

• Journal of Broadcast Engineering
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• v.10 no.4 s.29
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• pp.528-539
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• 2005

The H.264 has been adopted as the video codec for various multimedia services such as DMB and next-generation DVD because of its superior coding performance. However, the reference codec of the standard, the joint model (JM) contains quite a few algorithms which are too complex to be used for the resource-constraint embedded environment. This paper introduces very low-complexity H.264 encoding algorithm which is applicable for the embedded environment. The proposed algorithm was realized by restricting some coding tools on the basis that it should not cause too severe degradation of RD-performance and adding a few early termination and bypass conditions during the motion estimation and mode decision process. In case of encoding of 7.5fps QCIF sequence with 64kbpswith the proposed algorithm, the encoder yields worse PSNRs by 0.4 dB than the standard JM, but requires only $15\%$ of computational complexity and lowers the required memory and power consumption drastically. By porting the proposed H.264 codec into the PDA with Intel PXA255 Processor, we verified the feasibility of the H.264 based MMS(Multimedia Messaging Service) on PDA.

• Journal of Korea Multimedia Society
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• v.14 no.1
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• pp.54-75
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• 2011

PoC(Push-to-talk Over Cellular) is an integrated technology of group voice calls, video calls and internet based multimedia services. If a PoC user can not participate in the PoC session for various reasons such as an emergency situation, lack of battery capacity, then the user can use the PoC Box which has a similar functionality to the MM Box in the MMS(Multimedia Messaging Service). The RTSP(Real-Time Streaming Protocol) method is recommended to be used when there is a transmission session between the PoC box and a terminal. Since the existing VOD service uses a wired network, the packet size of RTSP-based VOD service is huge, however, the PoC service has wireless communication environments which have general characteristics to be used in RTSP method. Packet loss in a wired communication environments is relatively less than that in wireless communication environment, therefore, a buffering latency occurs in PoC service due to a play-out delay which means an asynchronous play of audio & video contents. Those problems make a user to be difficult to find the information they want when the media contents are played-out. In this paper, the following techniques and methods were proposed and their performance and superiority were verified through testing: cross-over dual reception buffering technique, advance partition multi-reception buffering technique, and on-demand multi-reception buffering technique, which are designed for effective picking up of information in media content being transmitted in short amount of time using RTSP when a user searches for media, as well as for reduction in playback delay; and same-priority packetization transmission method and priority-based packetization transmission method, which are media data packetization methods for transmission. From the simulation of functional evaluation, we could find that the proposed multiple receiving buffering and packetizing methods are superior, with respect to the media retrieval inclination, to the existing single receiving buffering method by 6-9 points from the viewpoint of effectiveness and excellence. Among them, especially, on-demand multiple receiving buffering technology with same-priority packetization transmission method is able to manage the media search inclination promptly to the requests of users by showing superiority of 3-24 points above compared to other combination methods. In addition, users could find the information they want much quickly since large amount of informations are received in a focused media retrieval period within a short time.