• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.8B
• /
• pp.492-501
• /
• 2007

UMTS-WLAN interworking approach can make the best use of the advantages of both networks by eliminating the stand-alone defects of the two services. For the interworking mechanisms of WLANs and UMTS networks, two major solutions have been proposed, namely loose coupling and tight coupling. The loose coupling approach provides separate data paths for WLAN and UMTS. On the other hand, the tight coupling provides a full integration of the WLAN network and the UMTS core network. The loose coupling has been preferred due to the simplicity and less reconfiguration requirement. However, loose coupling is worse in seamless mobility, QoS provision, and network security. In order to lessen the problems involved in the UMTS-WLAN interworking approaches, we propose a new interworking network architecture and a fast vertical handover scheme by employing Mobility Anchor(MA) for interworking between the two different networks. MA can enable authentication and session initialization before L2 handover of the mobile terminal, so that the seamless and fast vertical handover become possible. Thru analysis and numerical experiments, we proved that the proposed scheme has been validated.

• Journal of Power Electronics
• /
• v.18 no.4
• /
• pp.1278-1292
• /
• 2018

Inductive power transfer (IPT) technology allows for charging of electric vehicles with security, convenience and efficiency. However, the IPT system performance is mainly affected by the magnetic coupling structure which is largely determined by the coupling coefficient. In order to get this applied to electric vehicle charging systems, the power pads should be able to transmit stronger power and be able to better sustain various forms of deviations in terms of vertical, horizontal direction and center rotation. Thus, a novel cross-shaped magnetic coupling structure for IPT charging systems is proposed. Then an optimal cross-shaped magnetic coupling structure by 3-D finite-element analysis software is obtained. At marking locations with average parking capacity and no electronic device support, a prototype of a 720*720mm cross-shaped pad is made to transmit 5kW power at a 200mm air gap, providing a $1.54m^2$ full-power free charging zone. Finally, the leakage magnetic flux density is measured. It indicates that the proposed cross-shaped pad can meet the requirements of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) according to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA).

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.12
• /
• pp.67-74
• /
• 2004

AES is frequently used as a symmetric cryptography algorithm for the Internet. Wireless embedded systems increasingly use more conventional wired network protocols. Hence, it is important to have low-cost implementations of AES for thor The basic architecture of AES unrolls oかy one full cipher round which uses 20 S-boxes together with the key scheduler and the algorithm repeatedly executes it. To reduce the implementation cost further, the folded architecture which uses only eight S-box units was studied in the recent years. In this paper, we will study a low-cost AES implementation for wireless communication technology based on the folded architecture. We first improve the folded architecture to avoid the sixteen bytes of additional state memory. Then, we implemented a single byte architecture where only one S-box unit is used for data encryption and key scheduling. It takes 352 clocks to finish a complete encryption. We found that the maximum clock frequency of its FPGA implementation reaches about 40 MHz. It can achieve about 13 Mbps which is enough for 3G wireless communication technology.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.5
• /
• pp.117-123
• /
• 2016

In recent years, Personal Health Record (PHR) has emerged as a patient-centric model of health information exchange. The Personal Health Record (PHR) owners enjoy the full right of accessing their records anywhere and anytime making storage and retrieval more efficient. Due to the sensitivity and confidential nature of the PHR, however, the PHR is maintained in a secure and private environment with the individual determining rights of access. In this paper, we propose a system which enables access to the user's PHR in the event of emergency. In emergency situation where the user is unconscious, the emergency staff can use the PHR information to request a emergency access to the PHR server based on the predefined rights of access for PHR. Under the proposed system, the PHR owner can specify a fine grain access control policy during emergency situations.

• Proceedings of the IEEK Conference
• /
• 2001.10a
• /
• pp.76-79
• /
• 2001

In Japan in of today, there is no aspect in which the quantity of waste glass bottle discharged from ordinary homes decreases. Moreover, the kind of shape and color of the waste glass bottles are increasing little by little. In the recycling of the glass bottle, it becomes a problem that many kind of the color is abounding. It is possible to use the transparent glass bottle as raw material of the glassware. Since the reproduction of the color is difficult, the colored glass bottle is not possible to use as a raw material. Therefore, the processing of these glass bottles entirely depends on the reclamation. In Japan, the security of the new reclaimed land is very difficult for the reason of the environmental damage. Moreover, the life expectancy in many reclaimed lands is anticipated with within two years. Therefore, the development of the processing method of glass bottle other than reclamation becomes a rapid problem. At present it is examined that it is used of an aggregate of the colored pavement, as one of the application methods of colored glass bottle. The particle size of produced glass aggregate is also 5mm or less, because the thickness is 5mm or less on almost glass bottles. And almost glass particles have the sharp tip. The application as the aggregate is limited for this sharpness of the particle. This study was carried out for the purpose of the establishment of sharpness measuring method of the glass aggregate particle. It is possible that the injury degree to human in the handling is known, if showing the sharpness of the aggregate particle at the objective numerical value is possible. And the application of the glass aggregate is spread. In this research, the balloon fracture method was used for the sharpness measurement of the glass particle. This method is based on the completely new idea, and it is possible to express completely the possibility of injury to the human. It is reported with the detailed result in full paper, because this study is continuous in order to get the JIS which is industrial standard of Japan.

• Journal of Internet Computing and Services
• /
• v.15 no.1
• /
• pp.125-134
• /
• 2014

As the social media which was simple communication media is activated on account of twitter and facebook, it's usability and importance are growing recently. Although many companies are making full use of its the capacity of information diffusion for marketing, the adverse effects of this capacity are growing. Because social network is formed and communicates based on friendships and relationships, the spreading speed of the spam and mal-ware is very swift. In this paper, we draw parameters affecting malicious data diffusion in social network environment, and compare and analyze the diffusion capacity of each parameters by propagation experiment with XSS Worm and Koobface Worm. In addition, we discuss the structural characteristics of social network environment and then proposed malicious data propagation model based on parameters affecting information diffusion. n this paper, we made up BA and HK models based on SI model, dynamic model, to conduct the experiments, and as a result of the experiments it was proved that parameters which effect on propagation of XSS Worm and Koobface Worm are clustering coefficient and closeness centrality.

• The Korean Journal of Community Living Science
• /
• v.21 no.3
• /
• pp.285-298
• /
• 2010

This study aims to analyze teachers job satisfaction according to the working environment of teachers working in child-care centers and to investigate which variables of the working environment relate to job satisfaction of child-care teachers. The main results of this study were as follows. First, married teachers are more satisfied with the job itself, supervision, and colleague relations compared to teachers who are not married. Teachers with certificates are more satisfied with the job itself compared to teachers without certificates. Second, teachers's job satisfaction is significantly correlated with their salary, welfare, and colleague relations. Also teachers' job satisfaction is correlated with responsibility in the case that teachers have a good relation with their principal and child-care parents. Third, the results of this study show that teachers consider substitute teachers, vacation systems, day care systems, compliant with the ratio of teacher and children, job security, order of legal status as important. With regard to external compensation, teachers want salary increase, payment on overtime labor, flexible work-time, use of both full-time and part-time teachers, expansion of educational materials, increase on purchasing cost for textbooks and materials. To improve the quality of child-care teachers' working environment as well as their satisfaction, practical policies need to be implemented.

• Journal of KIISE:Computer Systems and Theory
• /
• v.32 no.10
• /
• pp.491-498
• /
• 2005

The Denial of Service(DoS) attacks, which are done by consuming all of the computing or communication resources necessary for the services, are known very difficult to be protected from. TCP has drawbacks in its connection establishment for possible DoS attacks. TCP maintains the state of each partly established connection in the connection queue until it is established completely and accepted by the application. The attackers can make the queue full by sending connection requests repeatedly and not completing the connection establishment steps for those requests. In this paper, we have designed and implemented the extended TCP for preventing from SYN Flood DoS attacks. In the extended TCP, the state of each partly established connection is not maintained in the queue until the connection is established completely. For the extended TCP, we have modified the 3-way handshake procedure of TCP and implemented the extended TCP in the Linux operating system. The test result shows $0.05\%$ delay more than original TCP, but it shows that the extended TCP is strong for SYN Flood attacks.

• Journal of Radiation Protection and Research
• /
• v.39 no.4
• /
• pp.218-221
• /
• 2014

Nuclear Safety Act had described the three types of licenses on radioisotope handling, such as a general license, a special license and a supervisory license. Applicants should be qualified by careers and qualifications for the education and training to acquire the licenses. In particular, the information on the estimation for the career is notified by Nuclear Safety and Security Commission(NSSC). In this paper, we suggest an improvement by analyzing survey data at the end of the education course on a license for the supervisor of radiation handling. We applied the learning evaluation to improve the education course. The level of satisfaction with the improved curriculum was compared with the existing curriculum. The improved curriculum with the learning evaluation has shown high grades of performance, i.e. above 4.0 points (full mark: 5.0 points) on the level of satisfaction and field application. The learning evaluation should be applied to the basic education course on a general license for radioisotope handling.

• Journal of Digital Convergence
• /
• v.11 no.3
• /
• pp.1-12
• /
• 2013

Present study examines the gender disparity in terms of its beneficiaries or benefit amount of National Pension of South Korea from the perspective of gender sensitivity. National Pension system has been manipulated and developed in order to maximize its universality. However, substantial gender differences are still found in terms of beneficiary number and benefit amount in the program. Benefit condition and benefit structure are determined assuming that male is the primary breadwinner in household and the primary regular full time worker in labor market. Women are only counted as dependents or excluded as unstable workers. As a result, women are fully or partially excluded from the program as they are excluded in other public sector such as labor market. Women's work (such as caring and housekeeping) are not taken into account in National Pension program. Policy suggestions for the National Pension of South Korea are also provided as the last part of this paper.