• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.11
• /
• pp.2569-2574
• /
• 2010

In this paper, we introduce an efficient energy management using a notion of virtual energy system for shared solar-powered sensor network. Virtual energy system is an abstraction that allows sensor network applications on a node to reserve their own fractions of the shared solar cell and the shared rechargeable battery, hence achieving logically partition of a shared renewable power source. Our results show that our design and implementation are reliable, lightweight and efficient, allowing proper isolation of energy consumption among applications.

• IE interfaces
• /
• v.16 no.3
• /
• pp.311-321
• /
• 2003

We propose the improved channel assignment and management methods for an efficient use of traffic channel resource for supporting 12.2 Kbps, 64 Kbps, and 384 Kbps traffic with the different quality of service(QoS) in the radio network controller(RNC) in asynchronous IMT-2000 system. We consider two types of traffic channel block assignments for utilizing the traffic channel efficiently; the Completely Shared(CS) channel assignment and the Partially Dedicated and Partially Shared(PDPS) channel assignment. The former is that all traffic channel blocks are completely shared with all traffic types. The latter is that some traffic channel block is independently assigned to each traffic type and the other blocks are completely shared with some traffic type. We also propose the traffic channel management method which consists of the block and task management step, for efficiently assigning, releasing, and managing the channel resource. Finally, we evaluate the performance through various numerical examples when applying our proposed channel block assignment and resource management methods.

• ETRI Journal
• /
• v.31 no.6
• /
• pp.784-794
• /
• 2009

We present a full HD (1080p) H.264/AVC High Profile hardware encoder based on fast motion estimation (ME). Most processing cycles are occupied with ME and use external memory access to fetch samples, which degrades the performance of the encoder. A novel approach to fast ME which uses shared multibank memory can solve these problems. The proposed pixel subsampling ME algorithm is suitable for fast motion vector searches for high-quality resolution images. The proposed algorithm achieves an 87.5% reduction of computational complexity compared with the full search algorithm in the JM reference software, while sustaining the video quality without any conspicuous PSNR loss. The usage amount of shared multibank memory between the coarse ME and fine ME blocks is 93.6%, which saves external memory access cycles and speeds up ME. It is feasible to perform the algorithm at a 270 MHz clock speed for 30 frame/s real-time full HD encoding. Its total gate count is 872k, and internal SRAM size is 41.8 kB.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.10a
• /
• pp.913-914
• /
• 2016

This paper analyzes the impact of the satellite TWTA non-linearity charateristics for shared band transmission technology to improve spectral efficiency in satellite communication system. In shared band transmission technology for star network, a hub and terminals use same frequency band. In order to receive terminals's signal a hub have to remove the its own DVB-S2 carrier. In this paper the non-linearity impact of satellite TWTA is analyzed for self-interference cancellation.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.7
• /
• pp.2568-2588
• /
• 2021

Shared mesh protection (SMP) protects traffic against failures occurring in a working path, as with linear protection, and allows resource sharing of protection paths with different endpoints. The SMP mechanism coordinates multiple protection paths that require shared resources when failures occur on multiple working paths. When multiple failures occur in SMP networks sharing limited resources, activation can fail because some of the resources in the protection path are already in use. In this case, a node confirming that a resource is not available has the option to wait until the resource is available or to withdraw activation of the protection path. In this study, we recognize that the protection switching time and the number of protected services can be different, depending on which option is used for SMP networks. Moreover, we propose a detailed design for the implementation of SMP by considering options and algorithms that are commonly needed for network nodes. A simulation shows the performance of an SMP system implemented with the proposed design and utilizing two options. The results demonstrate that resource utilization can be increased or protection switching time can be shortened depending on the option selected by the network administrator.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.41 no.3
• /
• pp.548-555
• /
• 2017

This study focuses on how clothing can increase in the age of the shared economy and as an alternative to the capitalist economy of the 21st century. This study investigates how infants and children use clothes as they undergo many changes based on physical growth, identifies use and disposal methods for surplus clothing from the perspective of a shared economy and explores plans to foster an environment for the healthy use of clothes. The objectives of this study are as follows. First, identify the need for new clothes based on physical changes in the human body; second, propose an alternative to permanent disposal by making used clothes appropriate for temporary disposal (renting and leasing). In sharing services, the condition and quality of the product were found to be the most important factors. The condition and quality of the product (70.0%) were the most important factors in sharing services. The sharing services for clothes and goods of infants and children could become popular quickly if there was a reliability guarantee offered by such sharing services. In addition, providing trial services and aggressive publicity for sharing services is urgent for the expansion of opportunities for general consumers.

• Journal of Korea Multimedia Society
• /
• v.20 no.5
• /
• pp.782-790
• /
• 2017

As most of the recent smart devices have NFC function the NFC mobile coupon will become one of the pervasive NFC applications. We need the secure NFC coupon protocols to issue and use NFC mobile coupon. In this paper, we analyze the security of the previous protocols and point out the problems of security. As the result of analysis, Premium M-coupon Protocol proposed by A. Alshehri and S. Schneider is the most secure but has unnecessary operations. We propose the Modified Premium M-coupon Protocol-1 with the unnecessary operations removed and show this protocol is secure by security analysis. Most of NFC mobile coupon protocols use the cryptography with the shared secret keys. We propose the Modified Premium M-coupon Protocol-2 without the shared secret keys and show this protocol is secure by security analysis.

• The Journal of the Korea Contents Association
• /
• v.22 no.2
• /
• pp.173-186
• /
• 2022

The purpose of this study is to investigate the influence of gamification strategies on improving participation and motivation of shared electric scooter users. To this end, this study derived the user type through the first research question of how the shared electric scooter usage behavior and pulse are, and derived user tasks and scenarios. The second research question, a shared electric kickboard app with gamification, was tested by users to see if it helps increase user participation and form motivation. As a result of the analysis, it was found that users were induced to be considerate of other users by using a combination of the motivational, relational, and self-expression strategies of gamification. Second, it was found that the use of motivation, achievement and reward, and reward visualization strategy elements promotes user's voluntary behavior. Third, through relationship, achievement, and reward strategies, users participated to create a positive culture of shared electric scooters, drawing immediate feedback, indicating that convenience has increased. In conclusion, it was found that the user helped to play a positive role in voluntary participation and motivation through the use of the shared electric kickboard service with gamification.

• Informatization Policy
• /
• v.21 no.3
• /
• pp.33-55
• /
• 2014

Public Shared Service Centers (PSSC) consolidate functions such as human resources, information technology, financial management or accounting into one office to serve an organization. A prominent example from the United States is the Federal Information Technology Shared Services Strategy. It supports mission, administrative, and infrastructure-related IT functions through providing organizations in the Executive Branch of the Federal Government (Federal Agencies) with policy guidance on the full range and lifecycle of intra- and inter-agency information technology (IT) shared services. This study looks at the Federal Information Technology Shared Services Strategy in order to draw lessons for fostering collaborative government through the use of PSSC. It finds the following factors are critical for success when implementing IT shared services: (1) agency leadership must be solidly behind their IT shared service plan, or the needed changes will not happen at the business unit, program, or system levels; (2) there must be a move away from internally-centered, program-specific thinking, and a move toward a paradigm of consuming and providing IT shared services with multiple groups whenever possible; and (3) successfully managing "loss of control" issues is central, and optimizing business processes is essential to move from stove-piped workflows to processes that work across the agency enterprise and beyond. Therefore, the study suggests that a Korean model of PSSC implementation be introduced, and that good IT Governance is a crucial component of PSSC strategies.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.6
• /
• pp.1343-1354
• /
• 2018

OAuth 2.0 bearer token and JWT(JSON web token), current standard technologies for authentication and authorization, use the approach of sending fixed token repeatedly to server for authentication that they are subject to eavesdropping attack, thus they should be used in secure communication environment such as HTTPS. In OAuth 2.0 MAC token which was devised as an authentication scheme that can be used in non-secure communication environment, server issues shared secret key to authenticated client and the client uses it to compute MAC to prove the authenticity of request, but in this case server has to store and use the shared secret key to verify user's request. Therefore, it's hard to provide stateless authentication service. In this paper we present a randomized token authentication scheme which can provide stateless MAC token authentication without storing shared secret key in server side. To remove the use of HTTPS, we utilize secure communication using server certificate and simple signature-based login using client certificate together with the proposed randomized token authentication to achieve the fully stateless authentication service and we provide an implementation example.