• Journal of Broadcast Engineering
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• v.13 no.6
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• pp.817-827
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• 2008

The terrestrial-digital multimedia broadcasting(T-DMB) is now provided for the public service and the number of receivers reaches 15 million at the present of August 2008. The service of T-DMB itself has been succeeded in the presence. It is however remained as a supplementary role of stationed TV. It is necessary to find an additional business model as a new media to acquire surplus escaping from the deficit of the present T-DMB service. In the present paper, data service of T-DMB is proposed as candidate of such solution. Especially, TTI(Traffic and Travel Information) service is proposed as a killer application using TPEG(Transport Protocol Experts Group). At present, TPEG has not been so popular in the sense of various user satisfaction. Thus the variety of service including bi-directional service using DMB2.0 as in the sphere of Web2.0 is necessary for the service providers. In the paper, the restriction of TPEG-POI(Point of Interest) application service using the conventional mobile communication infrastructure is indicated. To overcome such restriction, TPEG-UCM(User Created Message) application service model using individual bi-directional media which is initiated and interacting by the users is proposed. In the experiment, the application program shows the usability of the proposed method so that the implementation results show its operability.

• The Journal of the Korea Contents Association
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• v.11 no.9
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• pp.85-95
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• 2011

Recently, sudden interests of mobile cloud computing as well as conventional internet environment are rapidly increased as cloud computing spread out in our web society. Mobile devices including smart phone are rapidly changing in a wholesale way that covers hardwares, applications, and services. However, the Internet access using mobile device is not quite smooth in this local mobile internet environment which suffers from lack of understanding and observance of Web Standards. Although most of domestic web sites are developed focusing on various functions and eye-catching designs, this should became one of the main factors that make the usability and accessability decrease when accessing web with smart phones or table PCs. Therefore, this paper suggested a web interface that considered usability and accessability under mobile cloud environment and we tried to prove it via usability test. It could be found that there was an improvement of usability of interface of the main page that has been optimized to the mobile device environment suggested from the previous research we present, but this paper aimed to prove a usability improvement of total website as a whole by performing the usability test on the entire website. Selecting a special website optimized for mobile cloud computing, we prove an improvement of usability and accessibility. Therefore, we offer a guideline about user interface design applications to developers or companies who want to construct mobile website.

• The Journal of the Korea Contents Association
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• v.14 no.10
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• pp.706-722
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• 2014

Government and public institutions have been releasing a number of mobile applications in order to provide diverse public services in the mobile environment. However, due to their one-sided and fragmented service with the lack of adequate care for users, the utilization rate is extremely poor. Therefore, this study, based on a relevant literature review, identified and derived the five key factors (usefulness, convenience, interactivity, information credibility, and social pressure) for users' mobile service adoption. Then, through in-depth interviews with five users and five experts regarding the 'business support app' of one public agency (H institution) that specializes in SMEs, we found that all of these factors are important for users' mobile service adoption. Users' satisfaction could be significantly improved through real-time response to their needs. In addition, providing them with useful and tailored information can lead to mutual trust between public institutions and users. Consequently, as these user-oriented services can increase users' loyalty and boost the utilization rate of the public apps, public institutions should always put persistent efforts to cope with users' demands.

• Journal of the Korea Society of Computer and Information
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• v.17 no.10
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• pp.117-127
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• 2012

Identifying user requirements efficiently and reflecting them on the existing system is very important in a rapidly changing web and mobile environments. This study proposes the strategies to refining requirements and to prioritizing those refined requirements for changing of web and mobile application based on user requirements (e.g. mobile application comments, Q&A, reported information as discomfort factors). In order to refining the user requirements, those requirements are grouped by using the advancement of the software business of the Forum of standardization and the existing configuration-based programs. Then, we mapped them onto the PIECES framework to identifying whether the refined requirements are correctly reflected to the system in a way of valid and pure. To determine the priority of refined requirements, first, relative weights are given to software structure, requirements and categories of PIECES. Second, integration points on each requirement are counted to obtain the relative value of partial and overall score of a set of software structural requirements. In order to verifying the possibility and proving the effectiveness of proposing technique in this study, survey was conducted on changing requirements of mobile application which have been serviced at S University by targeting 15 people of work-related stakeholders.

• Journal of Internet Computing and Services
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• v.13 no.6
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• pp.63-74
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• 2012

In this paper, we develop an integrated management/monitoring system that supports to dynamically reconfigure information models for systems or applications managed by heterogeneous distributed systems. When the subsystems on diverse platforms are added, removed, or modified, the altered configurations should conform to the configuration information of the integrated management/monitoring system. Further, upon the system configurations being changed, the altered system configurations should be synchronized with the information on the integrated management/monitoring system. Moreover, availability should be assured during synchronization to the extent that users can access the monitoring information with no system halting. This paper focuses on notifying the integrated management/monitoring system of any changes in hardware/software configurations on any subsystems under its management, and on dynamically re-configuring the information about hardware and software being managed based on the information notified. Finally, we expect that this research will be contributory to carrying out reliable integrated management by reflecting the information on any heterogeneous distributed systems in the integrated management/monitoring system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.139-145
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• 2016

Dumbbell is the most basic topology that can be used in almost all kind of network experiment within it or just by little expansion. While Transmission Control Protocol TCP is the basic protocol that is used for the connectivity among networks and stations. TCP major and basic goal is to provide path and services to different applications for communication. For that reason TCP has to transfer a lot of data through a communication medium that cause serious congestion problem. To calculate the congestion problem, different kind of pre-cure solutions are developer which are Loss Based Variant and Delay Based Variant. While LBV keep track of the data that is going to be passed through TCP protocol, if the data packets start dropping that means congestion occurrence which notify as a symptom, TCP CUBIC use LBV for notifying the loss. Similarly the DBV work with the acknowledgment procedure that is used in when data ACK get late with respect to its set data rate time, TCP COMPOUND/VAGAS are examples of DBV. Many algorithms have been purposed to control the congestion in different TCP variants but the loss of data packets did not completely controlled. In this paper, the congestion control algorithms are implemented and corresponding results are analyzed in Dumbbell topology, it is typically used to analyze the TCP traffic flows. Fairness of throughput is evaluated for different TCP variants using network simulator (NS-2).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.530-540
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• 2020

Ecological momentary assessment (EMA) is a method that captures the current experience and behavior of subjects in real time in a natural environment. The data collected by EMA reveals alterations according to the time and context of experience and action. The Trier Inventory for Chronic Stress (TICS) is a tool that measures momentary stress, and is capable of measuring stress experienced in real life. This study was undertaken to verify the validity and reliability after translating the short form TICS into a Korean version. Totally, 89 police officers working at the police station in the capital participated in this study. The mobile application developed for this study was installed on their smartphones, and data were collected four times a day for seven consecutive days. Confirmatory factor analysis and content validity index (CVI) was applied to test the validity, and concurrent validity was evaluated by correlating with the occupational stress score. The model was validated by confirmatory factor analysis, and we obtained good reliabilities (I-CVI=0.83-1, RMSEA=0.104, SRMR=0.104, CFI=0.948, TLI=0.919, Cronbach's alpha=0.839). Our findings indicate the reliability, and validate use of the Korean tool for measuring momentary stress.

• Korean Journal of Community Nutrition
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• v.18 no.6
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• pp.588-598
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• 2013

This study was conducted to assess needs of educational mobile application (App) development for nutritional management and information on pregnant women. A total of 105 pregnant women were investigated on general characteristics, dietary habits, health behavior and needs for contents and composition of the application. The mean age of the subjects was 31.9 years and the mean gestation period was 25.4 weeks. The rate of skipping meal was 39.0% and the rate of irregular meal time was 46.6%. The consciousness of the meal as balanced nutrition and health was 19.9%. Eating out at least forth a week was 35.3%. Obtaining information about pregnancy and childbirth were internet (35.3%), hospital or health center (19.9%), books (17.1%), experience (15.2%), mobile (8.6%) and friends or acquaintances (4.8%). If the application is developed, subject replied 'frequently use' (51.4%), 'when needed' (47.6%) respectively. The favour topic in developing application were 'nutrition information of pregnant and fetal' (36.2%), 'weight management, feeding' (33.3%), 'food choice and cooking' (21.9%), 'shopping' (5.7%), 'example of menu' (1.9%), 'effect of smoking, drinking, exercising' (1.0%). The favorite content was 'include sufficient amount about information' (44.8%). Depending on the age and education level, the best age for pregnancy group have significantly higher ability for utilize and information gathering than old age pregnant group. Also the best age for pregnancy group have high demands of design, convenience and various contents in App development. Therefore, mobile application (App) for pregnant women could be widely used as an effective dietary guide.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.4
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• pp.871-878
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• 2017

As the interest of things to the Internet increases, the market of IoT grows larger and devices and protocols related with IoT are evolving.As these IoT devices and protocols evolve, There was a problem with interoperability. As a result, market and standard of IoT are confused, and communication between objects and objects is being hindered by different platforms. Currently, various IoT platforms are being developed and interoperability with heterogeneous platforms is under study, but the protocols used on each platform are limited and designed to have no generalized structure. Therefore, in this paper, we analyze services of HTTP, CoAP, and MQTT protocols, which are typical in the Internet market, and design services that enable selective protocol communication. We also design resources that apply the RESTful API to generalize platform usage. and We implemented the platform through database modeling for quick processing and safety of the collected data. Through this process, devices communicating with different protocols can be interworked on one platform and We propose a "generalized selective protocol based Internet object data collecting platform" that can be applied to various protocols.

• The Journal of Bigdata
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• v.1 no.1
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• pp.67-75
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• 2016

The study analyzed big data extracted from Google and social media to identify factors related to searches on cyber bullying in Korea and America. Korea's cyber bullying analysis was conducted social big data collected from online news sites, blogs, $caf{\acute{e}}s$, social network services and message for between January 1, 2011 and March 31, 2013. Google search trends for the search words of stress, exercise, drinking, and cyber bullying were obtained for January 1, 2004 and December 22, 2013. The main results of this study were as follows: first, the significant factors stress were cyber bullying that Korea more than America. Secondly, a positive relationship was found between stress and drinking, exercise and cyber bullying both Korea and America. Thirdly, significant differences were found all path both Korea and America. The study shows that both adults and teenagers are influenced in Korea. We need to develop online application that if cyber bullying behavior was predicted can intervene in real time because these actual cyber bullying-related exposure to psychological and behavioral characteristic.