• 한국HCI학회:학술대회논문집
• /
• 2009.02a
• /
• pp.1038-1044
• /
• 2009

Interests for User Interface directly influencing on usability are also growing as the competition between DCATV and IPTV come to the surface, according to getting activated Interactive TV market. Therefore, this study has the purpose to understand mental models of users for Interactive TV service & Interface. The methods for this study are as follows. First, as the step considering literature study, we compared differences between DCATV and IPTV and caught up the concepts of DCATV and IPTV among some types of Interactive TV. Second, we examinated and analysed Hello TV, C&M, Broad&TV, MegaTV, myLGtv as the step of analysis for examples for Interactive TV. Third, as the step of researches observing users we analysed usability problems caused by differences of mental models between DCATV and IPTV. As a result, we could find there are some differences for mental model of users in Interface & services between DCATV and IPTV Especially, it was found that users feel confused very much regarding perception of real time broadcasting and VOD. We regards this findings can be used as basic for concept makings of Interactive TV, when TV interface is developed in the future.

• Journal of Advanced Navigation Technology
• /
• v.17 no.1
• /
• pp.69-79
• /
• 2013

In this paper, DCT(Discrete Cosine Transform) and CAVLC(Context Adaptive Variable Length Coding) are co-designed as hardware IP with software operation of the other modules in H.264/AVC codec. In order to increase the operation speed, a new method using SHIFT table is proposed. As a result, enhancement of about 16(%) in the operation speed is obtained. Designed Hardware IPs are downloaded into Virtex-4 FX60 FPGA in the ML-410 development board and H.264/AVC encoding is performed with Microblaze CPU implemented in FPGA. Software modules are developed from JM13.2 to make C code. In order to verify the designed Hardware IPs, Modelsim program is used for functional simulation. As a result that all Hardware IPs and software modules are downloaded into the FPGA, improvement of processing speed about multiples of 16 in case of DCT hardware IP and multiples of 10 in case of CAVLC compared with software-only processing. Although this paper deals with co-design of H/W and S/W for H.264, it can be utilized for the other embedded system design.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.6
• /
• pp.1369-1380
• /
• 2011

Most existing mobile distance learning systems are asynchronous ones that allow students to download lecture video and presentation material. However, there are a few synchronous real-time mobile distance learning systems that support slide, annotation, feedback from student, and lecture video and audio at the same time. These live mobile distance learning systems have an advantage of supporting real-time interaction between students and a lecturer thereby making students understand the lecture better. But, they also have a disadvantage in the sense that they don't allow students to experience the past lecture. This problem can be solved by recording and replaying lecture session. So far, there are few mobile distance learning systems that support session recording and replay. This paper presents a synchronous mobile distance learning system that supports video and audio, slide with annotation, and real-time feedback from students, as well as session recording and replay, which is not supported by the existing mobile distance learning systems. The evaluation of the system among students shows that 61.3% of them were satisfied while 3.2% weren't.

• The Journal of the Korea Contents Association
• /
• v.9 no.8
• /
• pp.129-137
• /
• 2009

While the broadband network and multimedia technologies have been developing, the commercial market of digital contents also has been widely spreading with recently starting IPTV. As the IPTV services are getting to be generalized and popularized, the contents protection and authentication system tends to draw more attentions. So we need a system that can protect contents and allow only authenticated person to use right service by controling user authority and using content encryption. Until now, the conventional protection and authentication system is taking advantages of merits both in CAS and DRM. But the weak point of this system are in high costs, complexity and using HW. For resolving these problems, in this paper, we proposed IPTV contents protection and authentication system using OTP. When we transmit the content encrypted by OTP key using contents delivery technology, we operate XOR with contents using another settop-box's OTP key which was transmitted from distribution server. And contents are reconstructed and transmitted to the settop-box, In the end, downloaded content are encrypted by OTP key and are superior in content protection when contents redistribution. Since OTP use double-authentication elements in encryption process, this method is excellent in content protection. And it is very effective in cost aspect because it could be implemented by SW program. Another benefit is that we can shorten the development time period. In this paper, we propose and find its possibility as a new content protection and authentication method suitable for IPTV services.

• Journal of KIISE:Software and Applications
• /
• v.35 no.3
• /
• pp.197-206
• /
• 2008

In the mobile Internet environment, frequent communications between a mobile device and a content server are required for searching or downloading learning materials. In this paper, we propose an efficient prefetching technique to reduce the network cost and to improve the communication efficiency in the mobile dictionary. Our prefetching-based approach can be explained as follows. First, we propose an overall framework for the prefetching-based mobile dictionary. Second, we present a systematic way of determining the amount of prefetching data for each of packet-based and flat-rate billing cases. Third, by focusing on the English-Korean mobile dictionary for middle or high school students, we propose an intuitive method of determining the words to be prefetched in advance. Fourth, based on these determination methods, we propose an efficient prefetching algorithm. Fifth, through experiments, we show the superiority of our prefetching-based method. From this approach, we can summarize major contributions as follows. First, to our best knowledge, this is the first attempt to exploit prefetching techniques in mobile applications. Second, we propose a systematic way of applying prefetching techniques to a mobile dictionary. Third, using prefetching techniques we improve the overall performance of a network-based mobile dictionary. Experimental results show that, compared with the traditional on-demand approach, our prefetching based approach improves the average performance by $9.8%{\sim}33.2%$. These results indicate that our framework can be widely used not only in the mobile dictionary but also in other mobile Internet applications that require the prefetching technique.

• Journal of Korea Multimedia Society
• /
• v.11 no.10
• /
• pp.1409-1419
• /
• 2008

Inauthentic resources can be easily spread by P2P (Peer-to-Peer) participants due to the openness and anonymity of P2P networks. A possible way to restrict the distribution of inauthentic resources and prevent malicious peers from joining P2P networks is to exploit peers' reputation which reflect their past behaviors and are also helpful to predict peers' future behaviors. There is a possibility that some peers intentionally plays along with other peers in order to increase/decrease its reputation through false feedback exchanges. Therefore, we propose a new reputation management scheme, called TrustRRep (Trustable Resource sharing service using Reputation) scheme, which improves the trustworthiness and efficiency of P2P networks by identifying peers who give false feedback. The TrustRRep scheme is also capable of providing peers with the trustworthiness of shared resources by discriminating resources distributed by malicious peers. We implement the proposed TrustRRep scheme on the NS-2 simulator for evaluating its performance compared to the recent reputation management work available in literature. A case study on simulations shows that the proposed reputation management scheme yields efficient performance in terms of the minimal download ratio and dissemination of inauthentic resources, the efficient identification of peers who give false feedback, and the provisioning of the trustworthiness of peers' reputation. It also shows that the proposed TrustRRep scheme imposes the restrictions of participating P2P networks on a malicious peers by diminishing its trust value.

• The KIPS Transactions:PartD
• /
• v.11D no.5
• /
• pp.1063-1072
• /
• 2004

In the ASP(Application Service Provider) business, applications using database sometimes require some data from clients' databases. These days such data are extracted from client database using manual database operations as an EXCEL file and the ASP, once receiving this file, transfers it into the application's database using manual database operations. This paper describes how to deal with data transmitting between the client database and ASP database on the web without using database manual operations for data extraction and insertion. We propose a framework which enables to transmit client data in a systematical way, to match different attribute names of each database for sharing same attribute values, and to avoid exposing information about the network path of client database to the ASP. This approach consists of two steps of data processing. The first is extracting data from client database as XML format by using a downloaded client program from ASP site, the second is uploading and storing the XML file into the ASP database. The implemented prototype system shows the suggested data integration paradigm is valid and ASP business needing integration of client database can be activated using it.

• Journal of Convergence for Information Technology
• /
• v.8 no.5
• /
• pp.77-83
• /
• 2018

A modular robot that memorizes motion can be easily created and operated because it expresses by hand. However, since there is not enough storage space in the module to store the user-created operation, it is impossible to reuse the created operation, and when the modular robot again memorizes the operation, it changes to another operation. There is no main controller capable of operating a plurality of modular robots at the same time, and thus there is a disadvantage that the user must input directly to the modular robot. To overcome these disadvantages, a remote controller has been proposed that can be operated in the surrounding smart devices by designing web server and component based software using wired and wireless network. In the proposed method, various types of structures are created by connecting to a modular robot, and the reconstructed operation is performed again after storing, and the usefulness is confirmed by regenerating the stored operation effectively. In addition, the reliability of the downloaded trajectory data is verified by analyzing the difference between the trajectory data and the actual trajectory. In the future, the trajectory stored in the remote controller will be standardized using the artificial intelligence technique, so that the operation of the modular robot will be easily implemented.

• Journal of Sericultural and Entomological Science
• /
• v.51 no.2
• /
• pp.137-141
• /
• 2013

In this study, nucleotide sequence structures of intergenic transcribed spacer (ITS) 1, complete 5.8S ribosomal RNA gene and ITS 2 region were analyzed to identify three Peruvian entomopathogenic fungal isolates. The isolates had highly conserved sequence region in 5.8S rRNA gene and unique sequences in ITS 1 and 2 region among them. 5.8S rRNA gene regions were highly conserved and showed high homoloies among tested isolates. In contrast, ITS region showed species-specific sequence region, resulting in inter-genus differencies. Scanning electron microscopic images of these isolates supported the result of ITS-based identification. From these result, Peruvian entomopathogenic fungal isolate J270, J278, were identified as Beauveria bassiana and J271 was identified as Lecanicillium attenuatum.

• Journal of Korean Home Economics Education Association
• /
• v.23 no.2
• /
• pp.71-87
• /
• 2011

In this study, we investigate the individual-, parents-, and family-related variables affecting the internet overuse of adolescents by the gender, school grades and school systems, which is based on surveys of 480 students in the middle and high school, employing multiple regression analysis. Major findings are as follows. 1. In the case of male students, internet use was higher when the students are playing online games more often, when the students are under stress, or when they have lower self control. In the case of female students, internet use was higher when the students are playing online games more often or when the students are visiting pornographic sites more often. 2. In the case of middle school students, internet use was higher when the students play online games more often, when they use file downloads more often, when they have lower self control, or when they have parents who are setting lesser rules on the students' internet use. In the case of high school students, internet use was higher when they play online games more often, when they engage in internet club activities more actively, when they have lower self control, when they use e-mails less frequently, when they have fathers with better internet ability, or when they are under parents' strict control. 3. In the case of academic high school students, internet use was higher when they play online games more often, when they engage in internet club activities more actively, when they visit pornographic sites more often, when they have lower self control, when they have mothers with poor internet ability, when they use e-mails less frequently, or when they have fewer number of close friends. In the cases of vocational high school students, internet use was higher when they play online games more often, when they are under more stress, when they get better grades, when they have fathers with better internet ability, when they are under parents' strict control, or when they have lower self control.