• Journal of Information Processing Systems
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• v.7 no.2
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• pp.221-240
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• 2011

Vehicular networks are a promising application of mobile ad hoc networks. In this paper, we introduce an efficient broadcast technique, called CB-S (Cell Broadcast for Streets), for vehicular networks with occlusions such as skyscrapers. In this environment, the road network is fragmented into cells such that nodes in a cell can communicate with any node within a two cell distance. Each mobile node is equipped with a GPS (Global Positioning System) unit and a map of the cells. The cell map has information about the cells including their identifier and the coordinates of the upper-right and lower-left corner of each cell. CB-S has the following desirable property. Broadcast of a message is performed by rebroadcasting the message from every other cell in the terrain. This characteristic allows CB-S to achieve an efficient performance. Our simulation results indicate that messages always reach all nodes in the wireless network. This perfect coverage is achieved with minimal overhead. That is, CB-S uses a low number of nodes to disseminate the data packets as quickly as probabilistically possible. This efficiency gives it the advantage of low delay. To show these benefits, we give simulations results to compare CB-S with four other broadcast techniques. In practice, CB-S can be used for information dissemination, or to reduce the high cost of destination discovery in routing protocols. By also specify the radius of affected zone, CB-S is also more efficient when broadcast to a subset of the nodes is desirable.

• The Research Journal of the Costume Culture
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• v.27 no.5
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• pp.512-523
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• 2019

Contemporary University students are considered the Z generation who were born after 1995. They are more tech savvy than millennials. To target the generation, traditional class management platforms have evolved to smart LMS that is more customized and accessible for smart devices. Global level information search and collaboration can also be implemented using such smart LMS. However, switching from one LMS to another LMS requires great effort from teachers and support from staffs. This study measured the learners' perception of the system when they were exposed to a new smart-LMS. Blackboard Learn Ultra was used for 15 weeks and at the end of the semester, a questionnaire was administered to the students of these classes. Results indicated that experience with previous LMS discouraged students from adopting Blackboard Learn. Result of TAM modeling indicated that perceived usefulness, compared to perceived ease of use and attitude, was an effective aspect to bring positive acceptance of the system. A qualitative approach and network analysis were also conducted based on students' responses. Both positive and negative responses were detected. Inconvenience due to mechanical aspects was mentioned. Dissatisfaction compared to previous local LMS use was also mentioned. Mobile application and communication effectiveness were positive aspects. Revised course development and promoting how useful the system may help enhance the acceptance of the new system.

• Agribusiness and Information Management
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• v.10 no.2
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• pp.1-7
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• 2018

In the present day context of changing information needs of the farmers and diversified production systems there is an urgent need to look for the effective extension support system for the small and marginal farmers in the developing countries like India. The rapid developments in the collection and analysis of field data by using the spatial technologies like GPS&GIS were made available for the extension functionaries and clientele for the diversified information needs. This article describes the GIS and GPS based decision support system in precision agriculture for the resource poor farmers. Precision farming techniques are employed to increase yield, reduce production costs, and minimize negative impacts to the environment. The parameters those can affect the crop yields, anomalous factors and variations in management practices can be evaluated through this GPS and GIS based applications. The spatial visualisation capabilities of GIS technology interfaced with a relational database provide an effective method for analysing and displaying the impacts of Extension education and outreach projects for small and marginal farmers in precision agriculture. This approach mainly benefits from the emergence and convergence of several technologies, including the Global Positioning System (GPS), geographic information system (GIS), miniaturised computer components, automatic control, in-field and remote sensing, mobile computing, advanced information processing, and telecommunications. The PPP convergence of person (farmer), project (the operational field) and pixel (the digital images related to the field and the crop grown in the field) will better be addressed by this decision support model. So the convergence and emergence of such information will further pave the way for categorisation and grouping of the production systems for the better extension delivery. In a big country like India where the farmers and holdings are many in number and diversified categorically such grouping is inevitable and also economical. With this premise an attempt has been made to develop a precision farming model suitable for the developing countries like India.

• Journal of Intelligence and Information Systems
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• v.11 no.3
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• pp.1-23
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• 2005

Personalized reminder systems have to identify the user's current needs dynamically and proactively based on the user's current context. However, need identification methodologies and their feasible architectures for personalized reminder systems have been so far rare. Hence, this paper aims to propose a proactive need awaring mechanism by applying agent, semantic web technologies and RFID-based context subsystem for a personalized reminder system which is one of the supporting systems for a robust ubiquitous service support environment. RescorlaWagner model is adopted as an underlying need awaring theory. We have created a prototype system called NAMA(Need Aware Multi-Agent)-RFID, to demonstrate the feasibility of the methodology and of the mobile settings framework that we propose in this paper. NAMA considers the context, user profile with preferences, and information about currently available services, to discover the user's current needs and then link the user to a set of services, which are implemented as web services. Moreover, to test if the proposed system works in terms of scalability, a simulation was performed and the results are described.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.9-16
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• 2020

Wireless charging has been considered an essential part of recent mobile devices. Moreover, various wireless charging systems have emerged through many studies. Among the systems, in the 2D flat coil system, the transmitter coil and receiver coil are arranged horizontally as close as possible to improve the charging efficiency. Nowadays, the 3D coil system has been proposed by adding some slope to flat 2D coils to reduce the volume. On the other hand, the 3D coil system has a lower charging efficiency than the 2D system that decreases rapidly with increasing distance. This paper proposes a new system that improves the low efficiency and charging freedom, which are the drawbacks of the existing 3D systems. The proposed system was designed in three-dimensions, and another transmitter coil was added to the transmitter coil to improve the transmission efficiency and flexibility. The measurement showed that the charging efficiency of the proposed system was 40.10% when the distance between coils was 8 mm, which is 20.5 % improvement over the existing one. The proposed method can be applied when new wireless charging systems are designed and improve charging efficiency can be improved.

• Journal of the Korean Academic Society of Industrial Cluster
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• v.4 no.1
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• pp.1-13
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• 2010

The T-DMB which was developed by the convergence of digital broadcasting technology and communication technology provides us with very good quality of music like CD, and provides TV services in a super express train like the KTX whose velocity is over 300 Km per hour. The T-DMB is diffusing toward the world as a technology which is be able to provide the various convergent services of broadcasting and communication through mobile phone, PDA, dedicated terminal, and so on. A business model needed for the diffusion of the T-DMB toward the world was established and utilized to expand the T-DMB into Vietnam in the paper. In addition, this paper describes a case for the establishment of the T-DMB system in order to provide the paid services in Vietnam. It is expected that the expansion of the T-DMB into Vietnam will make a great contribution to the diffusion of the T-DMB toward the world.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.409-412
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• 2005

A digital content have been utilized extensively without being limited to one territory of communication, computer, broadcasting, Mobile etc. A digital contents industry have been raised to a key point industry of a knowledge information society. An information infra setup of a global unit was processing to the development of Internet therefor copyright protection a digital contents and system for the officer have been desired. Like this, according as digital contents do fetters to MPEG-4 is circulated, copyright problem was risen. So, people had a lot of interests to protect and manage copyright. Hereupon, MPEG of the IS0/IEC established IPMP(Intellectual Property Management and Protection) standard, and supplements and corrects continuously standard. Therefore, existing system does fetters to MPEG-4 need system that process IPMP information. Hereupon. in this paper, designed system module that is processed by IPMP extension standard that progress now, and embodied copyright protection and management system that user can insert and update IPMP information efficiently within whole or specification part of MPEG-4 digital contents.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.69-85
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• 2019

BeiDou navigation satellite system (BDS) is one of the four main types of global navigation satellite systems. The current system has been widely used by the military and by the aerospace, transportation, and marine fields, among others. However, challenges still remain in the BeiDou system, which requires rapid responses for delay-sensitive devices. A differential positioning algorithm called the data center-based differential positioning (DCDP) method is widely used to avoid the influence of errors. In this method, the positioning information of multiple base stations is uploaded to the data center, and the positioning errors are calculated uniformly by the data center based on the minimum variance or a weighted average algorithm. However, the DCDP method has high delay and overload risk. To solve these problems, this paper introduces edge computing to relieve pressure on the data center. Instead of transmitting the positioning information to the data center, a novel method called edge computing-based differential positioning (ECDP) chooses the nearest reference station to perform edge computing and transmits the difference value to the mobile receiver directly. Simulation results and experiments demonstrate that the performance of the ECDP outperforms that of the DCDP method. The delay of the ECDP method is about 500ms less than that of the DCDP method. Moreover, in the range of allowable burst error, the median of the positioning accuracy of the ECDP method is 0.7923m while that of the DCDP method is 0.8028m.

• Journal of Advanced Navigation Technology
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• v.24 no.3
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• pp.232-237
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• 2020

In this paper, a compact microstrip-fed dual-band planar antenna for global positioning system (GPS) and mobile handset applications is presented. Dual operating frequency bands are achieved by an open end L-shaped slot and a bent rectangular slot. The proposed antenna is designed and fabricated on the FR4 substrate with dielectric constant of 4.3, thickness of 1.6 mm and size of 57 × 57 ㎟. The measured impedance bandwidth (|S₁₁|≤ -10dB) of the fabricated antenna is 60 MHz(1550 ~ 1610 MHz) in the GPS band and 670 MHz (1690 ~ 2360 MHz) in the DCS / IMT-2000 band, covering the required bandwidths for GPS(1570 ~ 1580 MHz) and DCS / IMT-2000 (1710 ~ 2200 MHz) bands. In particular, it has been observed that antenna has a good omnidirectional radiation patterns as well as high gain of 2.36 dBi and its efficiency is more than 90 % over the entire frequency band of interest.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.10 no.2
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• pp.101-106
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• 2010

We propose an approach to estimate the real-time moving trajectory of an object in this paper. The object's position is obtained from the image data of a CCD camera, while a state estimator predicts the linear and angular velocities of the moving object. To overcome the uncertainties and noises residing in the input data, a Extended Kalman Filter(EKF) and neural networks are utilized cooperatively. Since the EKF needs to approximate a nonlinear system into a linear model in order to estimate the states, there still exist errors as well as uncertainties. To resolve this problem, in this approach the Kohonen networks, which have a high adaptability to the memory of the inputoutput relationship, are utilized for the nonlinear region. In addition to this, the Kohonen network, as a sort of neural network, can effectively adapt to the dynamic variations and become robust against noises. This approach is derived from the observation that the Kohonen network is a type of self-organized map and is spatially oriented, which makes it suitable for determining the trajectories of moving objects. The superiority of the proposed algorithm compared with the EKF is demonstrated through real experiments.