• The Journal of the Korea institute of electronic communication sciences
• /
• v.9 no.9
• /
• pp.1051-1056
• /
• 2014

Social Network Services are widely used by mass population and it is used as an important communications tool because it allows distribution of diverse and abundant amount of information. This thesis proposes to add a new valuable service function in social network for mobile-based civil complaint management. Therefore, we will develop a social network application for civil affair services that allows immediate civil compliant management while being able to share the contents related to civil affairs with other people. As a result of the experiment, the effect and efficiency of the method proposed in this thesis for social network-based civil affair services was proven. Hence, the social network for mobile-based civil affair services always provides new and improved service components. Moreover, discussing civil complaints in a social network point of view, we can expect high ripple effect and encourage more participation of public users dealing with civil affairs.

• Journal of IKEEE
• /
• v.15 no.3
• /
• pp.218-226
• /
• 2011

In this paper, the leaky electric field intensity of outdoor CATV facilities on CDMA mobile service band defined in technical regulation related with CATV is investigated if appropriate or not. From experimental and theoretical analysis results, Maximum allowable power level of CATV leakage should be -110dBm/1.23MHz. Also, the CATV leakage intensity thresholds, which may not nearly give an impact on the uplink performance of CDMA mobile base station for outdoor background noise of -100~-80dBm/1.23MHz to be measured in outdoor environment, couldn't conform to the current CATV technical regulation. Therefore, the leakage intensity in the current CATV technical regulation is rated as a too much low level in view of an overly worst case.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.8 no.5
• /
• pp.137-147
• /
• 2008

Recently, Power and thermal management are becoming major concerns in computer system design. The energy efficiency is an important attribute of the mobile and embedded systems. Today's powerful mobile processors needs more energy and longer battery life. Many research has been focused to reduce energy consumption for the mobile processors.In this paper, performance monitoring system for the Power-management techniques is implemented for Intel's XScale microarchitecture-based Marvell PXA320 processor on Windows CE platform. It also provides software interface for changing DVFS configuration. Performance and power consumption are measured for benchmark programs through performance counter value and voltage/current measurements on LabVIEW platform. By using the developed monitoring system, it is possible for dynamic power management to track processor's workload and to determine the actual power consumption.

• Journal of KIISE:Information Networking
• /
• v.31 no.2
• /
• pp.158-170
• /
• 2004

Mobile IP is a base protocol to support host mobility in IP-based wireless network. It is well known that the protocol contains two main delay factors on a handoff process; one is to detect a host movement, and the other is to register the host's current location to its home network. This paper examines Layer 2(L2) handoff procedure in the IEEE 802.11 Wireless LAN, and identifies these L2 triggers that can be usefully applied to Layer 3(L3) handoff. Then, the MCAA(Multiple-Casting using Anchor Agent) mechanism is proposed. It makes use of the L2 trigger and the network topology to construct an anchor agent dynamically, and the multiple-casting scheme to prevent an ongoing packet to be lost. Using a network simulator, the proposed mechanism has been evaluated the handoff delay and the packet lost point of view, in comparison with the regional registration protocol which is the most well known micro mobility support mechanism.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.4
• /
• pp.1957-1968
• /
• 2013

This study figured out how could mobile contents quality factors, such as usefulness, accuracy, timeliness, entertaining, economic, security etc., affect satisfaction by user individuality using empirical analysis with an aim of finding difference in content quality factors which have an influence on mobile contents satisfaction by user characteristics in integrated view systemically. The result of analysis shows that usefulness has an influence on satisfaction in principle regardless of user characteristics. This study discovered that both of usefulness and entertaining are significant to satisfaction in the groups with high-user individuality. On the other hand, in the groups with low-user individuality both of usefulness and accuracy affect satisfaction. Findings show that contents preference can be different based on user characteristics. Implications are discussed and limitations are proposed based on empirical analysis.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.19 no.4
• /
• pp.451-456
• /
• 2009

In this paper, a virtual force is generated and fed back to the operator to make the teleoperation more reliable, which reflects the relationship between a slave robot and an uncertain remote environment as a form of an impedance. In general, for the teleoperation, the teleoperated mobile robot takes pictures of the remote environment and sends the visual information back to the operator over the Internet. Because of the limitations of communication bandwidth and narrow view-angles of camera, it is not possible to watch certain regions, for examples, the shadow and curved areas. To overcome this problem, a virtual force is generated according to both the distance between the obstacle and the robot and the approaching velocity of the obstacle w.r.t the collision vector based on the ultrasonic sensor data. This virtual force is transferred back to the master (two degrees of freedom joystick) over the Internet to enable a human operator to estimate the position of obstacle at the remote site. By holding this master, in spite of limited visual information, the operator can feel the spatial sense against the remote environment. It is demonstrated by experiments that this collision vector based haptic reflection improves the performance of teleoperated mobile robot significantly.

• Journal of the Korea Society of Computer and Information
• /
• v.15 no.3
• /
• pp.1-10
• /
• 2010

As processor platforms are continuously moving toward wireless mobile systems, embedded mobile processors are expected to perform more and more powerful, and therefore the development of an efficient power management algorithm for these battery-operated mobile and handheld systems has become a critical challenge. It is well known that a memory system is a main performance limiter in the processor point of view. Although many DVFS studies have been considered for the efficient utilization of limited battery resources, recent works do not explicitly show the interaction between the processor and the memory. In this research, to properly reflect short/long-term memory access patterns of the embedded workloads in wireless mobile processors, we propose a memory buffer utilization as a new index of DVFS level prediction. The simulation results show that our solution provides 5.86% energy saving compared to the existing DVFS policy in case of memory intensive applications, and it provides 3.60% energy saving on average.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.9 no.5
• /
• pp.578-588
• /
• 1998

In this paper, we analyzed the propagation characteristics of polarization diversity in the view of diversity gain, cross correlation coefficient and average received signal strength, and compared it with those of space diversity. From the results, we could confirm that in the care of line of sight(LOS), space diversity gain is bigger than polarization diversity gain by 2 dB and the diversity gain of mobile transmitting with 90 degree is bigger than that of mobile transmitting with 45 degree by 1 dB. However, in the area of non-line of sight(NLOS), the diversity gains were all most the same in two diversity schemes and in specular cases, polarization diversity showed better performances. Also it was verified that under the NLOS conditions, diversity gain of mobile transmitting with 45 degree was at least 1 dB bigger than that of mobile transmitting with 90 degree.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.05a
• /
• pp.794-796
• /
• 2016

Recently terrestrial mobile multimedia broadcasting(T-DMB) service is being provided throughout the country are expanding and demand is increasing day by day. T-DMB has the advantage of being cheaper in cost than installing another mobile multimedia broadcasting. However, there are a variety data of additional and provide it difficult for localized emergency alert broadcasting services. In this paper, a method to solve this problem feature was designed to restrict incoming unidirectional / bidirectional authentication via T-DMB system. In the mobile device is received by the T-DMB broadcasting service authentication mechanism for re-transmission to the mobile device, and T-DMB receiving other registered users can view it impossible to receive the broadcast. Through the proposed system it is considered to be able to solve the problems of the existing T-DMB technology.

• The KIPS Transactions:PartD
• /
• v.8D no.3
• /
• pp.265-272
• /
• 2001

In case of implementing a complicated application like WAP (Wireless Application Protocol) in a mobile terminal with the characteristics of bare machine and versatile kernel aspects of which are control, interrupt and IPC(Inter Process Communication), a special methodology should be needed. If not, it will cause more cost and human resources, even delayed product into launching for the time-to-market. This paper suggests AKL, (Abstract Kernel Layer) for the design and implementation of WAP on basis of multi-platform. AKL is running on the various kernel including REX, MS-DOS, MS-Window, UNIX and LINUX. For the purpose of it, AKL makes machine-dependant features be minimized and supports a consistent interface on API (Application Program Interface) point of view. Therefore, it makes poring times of a device be shorten and makes easy of maintenance. We validated our suggestion as a consequent of porting WAP into PlamV PDA and mobile phone with AKL.