• The Journal of Society for e-Business Studies
• /
• v.12 no.4
• /
• pp.1-15
• /
• 2007

Traceability links are logical links between individual requirements and other system elements such as architecture descriptions, source code, and test cases. These are useful for requirements change impact analysis, requirements conflict analysis, and requirements consistency checking. However, establishing and maintaining traceability links places a big burden since complex systems have especially yield an enormous number of various artifacts. We propose a feature-oriented requirements tracing method to manage requirements with cost benefit analysis, including value consideration and intermediate catalysis using features. Our approach offers two contributions to the study of requirements tracing: (1)We introduce feature modeling as intermediate catalysis to generate traceability links between user requirements and implementation artifacts. (2)We provide value consideration with cost and efforts to identify traceability links based on prioritized requirements, thus assigning a granularity level to each feature. In this paper, we especially present the results of a case study which is carried out in Apartment Ubiquitous Platform to integrate and connect home services in an apartment complex in details.

• Convergence Security Journal
• /
• v.14 no.2
• /
• pp.35-41
• /
• 2014

With ubiquitous computing and network, the concern of government, business and academy for IT or ICT convergence has been increased. In this paper, through the analysis of keyword trend for ICT convergence services from 2000's mid, the efficient policy is proposed by estimating the understanding and concern of common people. In addition to, the concept and development step of convergence are analyzed, and the keyword analysis for the ICT convergence services defined in TTA is performed. The services are classified into smart home work transportation, Health ICT, RFID USN, M2M IoT, e-Navigation, intelligent robot, and the keywords for each service are analyzed. The analytic results indicate that the keyword trend varies in the time, and highly indexing keywords and new trend are defined. To provide the efficient ICT services, the new ICT convergence services needed for customer will be proposed with new IT technology development, IT standard, law management, and policy provisioining.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.6
• /
• pp.85-91
• /
• 2014

Nowadays, Dynamic lighting control and management skills are studied and used. If the system which is to manage multiple intelligent spot applied ubiquitous service technology is built with decision making and used in the complex intelligent space like a apartment then will improve energy efficiency and provide comfortability in optimal conditions. To solve this problem distributed autonomous control middleware and energy management system which process data gathering by zigbee mesh network and search proper services to save energy by the existing state of things is necessary. In paper we designed DDLEMS (Distributed Dynamic Lighting Energy Management System) that is to service duplex communication embedded by software based home server platform to provide mobile services in the smart place and support decision making about energy saving to the best use of wireless censor node and controled network, energy display devices.

• Journal of Communications and Networks
• /
• v.2 no.1
• /
• pp.5-17
• /
• 2000

cdma2000 offers several enhancement as compared to TIA/EIA-95, although it remains fully compatible with TIA/EIA-95 systems and allows for a smooth migration from one to the other-Major new capability include:1)connectivity to GSM-MAP in addition to IP and IS-41 networks; 2) new layering with new LAC and MAC architectures for improved service multiplexing and QoS management and efficient use of radio resource ;3) new bands and band widths of operation in support of various operator need and constraints, as well as desire for a smooth and progressive migration to cdma 2000; and 4) flexible channel structure in support of multiple services with various QoS and variable transmission rates at up to 1 Mbps per channel and 2 Mbps per user. Given the phenomenal success of wireless services and desire for higher rate wireless services. improved spectrum efficiency was a major design goal in the elaboration of cdma2000. Major capacity enhancing features include; 1) turbo coding for data transmission: 2)fast forward link power control :3) forward link transmit diversity; 4) support of directive antenna transmission techniques; 5) coherent reverse link structure; and 6) enhanced access channel operation. As users increasingly rely on their cell phone at work and at home for voice and data exchange, the stand-by time and operation-time are essential parameters that can influence customer's satisfaction and service utilization. Another major goal of cdma2000 was therefore to enable manufacturers to further optimize power utilization in the terminal. Major battery life enhancing features include; 1) improved reverse link performance (i.e., reduced transmit power per information bit; 2) new common channel structure and operation ;3) quick paging channel operation; 4) reverse link gated transmission ; and 5) new MAC stated for efficient and ubiquitous idle time idle time operation. this article provides additional details on those enhancements. The intent is not to duplicate the detailed cdma2000 radio access network specification, but rather to provide some background on the new features of cdma2000 and on the qualitative improvements as compared to the TIA/EIA-95 based systems. The article is focused on the physical layer structure and associated procedures. It therefore does not cover the MAC, LAC, radio resource management [1], or any other signaling protocols in any detail. We assume some familiarity with the basic CDMA concepts used in TIA/EIA-95.

• 전자공학회논문지 IE
• /
• v.49 no.2
• /
• pp.58-64
• /
• 2012

In this paper, we proposed a distributed gateway for ubiquitous healthcare system. We also designed and implemented protocol conversion and processing algorithms to exchange a seamless information, the bio signals between the databases and the receiving devices from ZigBee to gateway and from the gateway to database and network. The distributed gateway system consists of the bio signal acquisition, ZigBee modules, distributed databases, and gateways. The bio signals detected by the ZigBee module are sent to the gateway. The distributed gateway analyzes the data being transferred, sends those to the receiving devices, and lets the authorized personnel access. The proposed system can be utilized in various fields including activity analysis for the elderly, security systems, home network service, and so on.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.11 no.2
• /
• pp.102-110
• /
• 2012

ZigBee networks developed for low power and short range communication are being used as home network solution for ubiquitous computing. However, as smart phones and tablet PCs have been widely used, WLANs which use same frequency with ZigBee networks have been increasingly used. Therefore, radio frequency interference causes many problems. To solve radio frequency interference problem among ZigBee networks and WLANs, many researches focus on designing interference minimization schemes in ZigBee networks. However, existing schemes have problems that have waste of resource for detecting interference, and have unnecessary time to avoid interference. In this paper, we propose an interference minimization scheme to solve radio frequency interference in ZigBee networks. The proposed scheme detects interference using ACK mechanism to reduce waste of resource, and avoids interference using table driven channel hopping scheme which is faster than existed schemes. The performance of proposed interference minimization scheme is evaluated by using OPNET simulator. Through the simulation result, we prove that proposed scheme has faster channel hopping than existing schemes.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.3 s.345
• /
• pp.111-117
• /
• 2006

Developing a home network and a ubiquitous infrastructure requires various communication techniques and devices with more advanced hardware. With this development, increasing realtime access to multimedia data results in rapid degradation of qualify for multimedia playback. This paper presents a traffic allocation technique based on MPP(Media Preference for Presentation) that can steadily maintain multimedia playback quality by adaptively allocating streaming traffic requested from clients with different playback performances. Media preference is defined in accordance with content popularity and playback performance of client devices. Through experiments when requested stream data exceeds processing ability of a midea server, the proposed allocation technique shows 10% quality improvement comparing to the system without applying the proposed allocation technique.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.1
• /
• pp.23-30
• /
• 2014

Recently, Light Emitting Diode(LED) light is changing the light equipment, which was considered just as a power-controlled device in home-network, into a IT convergence device by combining illumination function with wireless communication. As a result, Visible Light Communication(VLC) becomes a more practical solution to ubiquitous networks due to the more spread of LED light. One of representative applications using VLC is a VLC-based indoor navigation system which can provide high-accuracy indoor localization. In this paper, we model and implement a VLC based-indoor navigation system in which a fluorescent light type of LED lamp, which is normally used in large buildings, and smart devices, which are usually used by users, are utilized as main components for indoor navigation. Subsequently, it is expected that the paper can contribute to make VLC applications be more active.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.5
• /
• pp.203-210
• /
• 2011

The current sensor network analyzes the data collected by the sensing of fixed sensor nodes and provides a service. However, this method cannot actively handle the state and the change in the position of people, 'the target for sensing and the change in the environment', including home automation, building automation and real-time road & weather information, and healthcare environment, etc. To support a dynamic situation which is appropriate for an individual in this diverse environment, it is necessary to provide actively differentiated specific information according to the movement of people and the changes in the environment. In this study, a individualized sensor mobile agent middleware which provides the individualized information (the location of fire incidence and the trace for the path of spread), has been realized through the sensor network environment constructed by the installation of wireless sensor nodes mounted with mobile agent middlewares in buildings.

• Journal of the HCI Society of Korea
• /
• v.1 no.1
• /
• pp.89-95
• /
• 2006

Prospective memory is memory for activities to be performed in the future, such as remembering to purchase a piece of fruit on the way home or remembering to give someone a telephone message. Due to the decrease in memory ability, the aged have difficulty in remembering the tasks they intended to perform in the future. Employing survey and experimental methods, we identified the UI requirements for enhancing prospective memory (PM) performance for the aged. The survey included subjective assessments of PM performance for the aged and their preferred usability components and PM-supporting systems in an ubiquitous computing environment. The experiment examined the effect of contextual cues on PM performance for the young and the aged. Practical implications of our results were discussed in the respects of PM-supporting UI design requirements for the aged.