• Journal of Communications and Networks
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• v.11 no.6
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• pp.574-588
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• 2009

Although much research has been conducted in the area of authentication in wireless networks, vehicular ad-hoc networks (VANETs) pose unique challenges, such as real-time constraints, processing limitations, memory constraints, frequently changing senders, requirements for interoperability with existing standards, extensibility and flexibility for future requirements, etc. No currently proposed technique addresses all of the requirements for message and entity authentication in VANETs. After analyzing the requirements for viable VANET message authentication, we propose a modified version of TESLA, TESLA++, which provides the same computationally efficient broadcast authentication as TESLA with reduced memory requirements. To address the range of needs within VANETs we propose a new hybrid authentication mechanism, VANET authentication using signatures and TESLA++ (VAST), that combines the advantages of ECDSA signatures and TESLA++. Elliptic curve digital signature algorithm (ECDSA) signatures provide fast authentication and non-repudiation, but are computationally expensive. TESLA++ prevents memory and computation-based denial of service attacks. We analyze the security of our mechanism and simulate VAST in realistic highway conditions under varying network and vehicular traffic scenarios. Simulation results show that VAST outperforms either signatures or TESLA on its own. Even under heavy loads VAST is able to authenticate 100% of the received messages within 107ms. VANETs use certificates to achieve entity authentication (i.e., validate senders). To reduce certificate bandwidth usage, we use Hu et al.'s strategy of broadcasting certificates at fixed intervals, independent of the arrival of new entities. We propose a new certificate verification strategy that prevents denial of service attacks while requiring zero additional sender overhead. Our analysis shows that these solutions introduce a small delay, but still allow drivers in a worst case scenario over 3 seconds to respond to a dangerous situation.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.465-471
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• 2018

Recently, biometric technology has begun to be used as a fusion of IT technology and financial system. Using this biometric technology, FIDO(Fast Identity Online) technology, Samsung and Apple started Samsung Pay and Apple Pay service. FIDO authentication technology replaces existing authentication methods such as passwords. Among the biometric technologies, fingerprint recognition technology is attracting attention because it can minimize the device and user rejection at a relatively low price. However, fingerprint information has a limited number of users and it can not be reused if fingerprint information is leaked by an external attacker. Therefore, in this paper, we propose a method to authenticate a user using EEG signal which is one of biometrics technologies. W propose a method to use EEG signal measurement value in FIDO system by using convenience channel by using short channel EEG device. And propose a method to utilize EEG signal when the user recognizes a specific entity by measuring the EEG signal before and after recognizing a specific entity.

• Journal of Information Technology Application
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• v.3 no.2
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• pp.67-82
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• 2001

The ILOF project addresses the needs of logistics industrial organizations to reduce information processing time, improve added and residual value of information and reduce processing and transportation costs. It deals with the information supply chain information systems shared by vertical partner as important entity, whose performance and optimization very significantly affects the efficiency and performance of logistics industries. This paper deals with logistics information exchange systems based on supply chain management, focusing on sharing database and processes between partners such as shipper, logistics broker, transportation company, shipping company etc., for smoothing the information flow, enhancing consumer service and reducing communication fee and labour costs. The significance of contribution of this research is the provision of a model for logistics information exchange including entity relationship diagram, data flow diagram and functions which is able to facilitate the formulation of a customer driven supply chain information network, there by enhancing the competitive edge of companies in logistics industries on local and global basis.

• Journal of Korea Spatial Information System Society
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• v.4 no.1 s.7
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• pp.15-25
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• 2002

The OGC(OpenGIS Consortium), which is standardization organization of geographic data, have been studied standard for geographic data such as GML and GML based annotation for image and map. Annotation for map is applicable in various ways, understanding about geographic data, decision making and exchange of communication. For instance, Map annotation can be used for highlighting tour-course as symbols or explaining it as text on a map in tourism. This study suggests some annotation methodology for national digital map and presents a simple implementation of it. Firstly, this study suggests a way of updating OGC annotation schema which corresponds with DXF format and creating a GML application schema using the updated OGC annotation schema. Also it suggest a way of converting instance documents of annotated map to VML document with XSLT and VML for display. Later, it is needed to study for supporting another formats as well as DXF format. In addition, it is needed to study for managing the history of updated map entity with annotation in Local governments UIS(Urban Information System) in practical aspects.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.5
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• pp.885-896
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• 2013

MTC(Machine Type Communications), providing a variety of services anytime and anywhere by connecting the cellular network to the machine and things without human intervention, is being considered as a major challenge of the next-generation communications. Currently, When a massive MTC devices simultaneously connect to the network, each MTC device needs an independent access authentication process. Because of this process, authentication signaling congestion and overload problems will cause in LTE-Advanced. In this paper, we propose a group-based authentication protocol and a key management protocol. For managing the MTC devices as group units, the proposed protocol elects a group leader and authentications only once with the core network. After the authentication is completed, a group leader manages the rest members and MME(Mobility Management Entity) by constructing a binary tree. Finally, the propose protocol analysis show that the proposed protocol not only can reduces the authentication signaling which generated in between the MTC devices and the core network but also can manages the MTC devices, efficiently.

• Annals of Clinical Neurophysiology
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• v.4 no.1
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• pp.44-50
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• 2002

Introduction : Orthostatic tremor develops in the legs while standing up with no weakness, pain or imbalance in the leg and the tremor is characteristically not observed when walking. However there have been some confusions about orthostatic tremor in several aspects. For the past ten years, we have observed 4 patients with orthostatic tremor. In each case tests were performed to investigate the following three important areas of inquiry about orthostatic tremor. Firstly, whether this disorder is an independent diagnostic entity or a variant of essential tremor. Secondly, whether the progress of this disorder is specifically related with standing posture. Lastly, the nature of the pathophysiologic mechanism behind the appearance of the tremor when standing after the lapse of a certain latent period and its disappearance upon the commencement of walking. Methods : Our 4 cases of orthostatic tremor were studied clinically, electrophysiologically, and pharmacologically. Electrophysiological tests included tremor spectrum test and electromyography. Results : We observed the presence of this tremor in several other tonic postures, as well as its absence, in a vertically lifted position from all our cases. Our cases registered a variable tremor frequency between 5 and 12 Hz according to the tremor spectrum test and EMG. Furthermore all our 4 cases demonstrated patterns of both synchronous EMG activity and alternating EMG activity at various times in homologous muscles of both legs. Orthostatic tremor was improved significantly with propranolol as well as clonazepam. Conclusions : From the results of our study we drew the following conclusions. It is probable that orthostatic tremor is simply a variant of essential tremor rather than being an independent diagnostic entity and that in most cases its development is specifically related with muscle contraction rather than merely with the act of standing. Furthermore we discovered a clue in the previously described neural control mechanism that the nuclear bag fibers in the muscle spindle have lag time of several seconds in their response to muscle strength and that their baseline does not reset fully in rapidly moving muscle. This neural control mechanism could offer sufficient explanation for the phenomena of tremor appearance when standing and disappearance when walking in orthostatic tremor.

• Journal of the Korean Society of Costume
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• v.66 no.1
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• pp.13-27
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• 2016

There are differences in preference according to the brand signal explicitness when selecting fashion luxury brand, and the purpose of this study is to verify the moderating effects of self-construal and implicit theory in relation to those preferences. This study divided the experiment design into two $2{\times}2$ mixed design studies: Study 1 and Study 2. The study 1 was composed of the following factors: brand signal explicitness(subtle vs. explicit signal) and self-construal(independent vs. interdependent self-construal). Study 2 was composed of the following factors: brand signal explicitness( subtle vs. explicit signal) and Implicit theory(entity vs. incremental theorist). Convenience sampling was conducted to find the subjects of study 1 and study 2. Study 1 analyzed data from 172 women in Seoul, Gyeonggi-do and Busan who prefer luxury brand, and study 2 used data from 138 women. The results of this study are as follows. 1) Independent self-construal primed group was shown to prefer subtle signal product to explicit signal product, whereas interdependent self-construal priming group preferred explicit signal product to subtle signal product. 2) The entity theorist to prefer explicit signal product to subtle signal product. On the other hand, the incremental theorist did not show significant difference in the preference between subtle and explicit signal products. Therefore, the results of the present study shown the importance of understanding consumers through the difference depending on consumer inclination and psychology, recommending preferred luxury brand according to the inclination of the target customers, and establishing segmented marketing strategy to captivate consumers with these various characteristics.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1119-1127
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• 2012

The one of features of M2M communications, which are recently attracted attention as a future business of mobile communications, is that there is a large number of devices compared with traditional communication services. Hence, the control signal that are generated by the M2M devices may cause a significant congestion in the network and in order to solve this problem, a standardization is progressing for reducing the redundant signaling by managing M2M devices as a group in 3GPP standardization. In this paper, we propose a method of group based mobility management by managing M2M devices that have the same mobility as a group. In the proposed method, M2M devices that have the same mobility are grouped by the Mobility Management Entity (MME) and the MME elects a group header among the M2M devices in the group. Then, the group header performs the Tracking Area Update (TAU) on behalf of the group members to reduce the signaling overhead of mobility management. With the proposed method, we can achieve 80% decrease of the signaling overhead of mobility management compared with the case where each M2M device individually performs its TAU procedure.

• Journal of Internet Computing and Services
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• v.7 no.4
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• pp.67-77
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• 2006

Wrappers play an important role in extracting specified information from various sources. Wrapper rules by which information is extracted are often created from the domain-specific knowledge. Domain-specific knowledge helps recognizing the meaning the text representing various entities and values and detecting their formats However, such domain knowledge becomes powerless when value-representing data are not labeled with appropriate textual descriptions or there is nothing but a hyper link when certain text labels or values are expected. In order to alleviate these problems, we propose a probabilistic method for recognizing the entity type, i.e. generating wrapper rules, when there is no label associated with value-representing text. In addition, we have devised a method for using the information reachable by following hyperlinks when textual data are not immediately available on the target web page. Our experimental work shows that the proposed methods help increasing precision of the resulting wrapper, particularly extracting the title information, the most important entity on a web page. The proposed methods can be useful in making a more efficient and correct information extraction system for various sources of information without user intervention.

• Journal of Internet Computing and Services
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• v.10 no.4
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• pp.71-85
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• 2009

The demand for mobile database applications has been rapidly increased with the growth of mobile users and the development of wireless Internet technology. But the productivity of mobile applications is low and it takes much time to manage the versions of applications because the user interface and query processing code of applications is manually written. In this paper, we describe the design and implementation of the MobileGen that is a script generator for mobile database applications. The generated scripts enhance mobile application productivity by providing the code for operating with a database and processing user queries. Each script provides a corresponding deck that is a set of related cards as user interface. The MobileGen supports easy version management of generated applications and the MobileGen itself because it is based on the templates that are frameworks for scripts. Moreover, the MobileGen provides not only the interested entity but also the entities that are related directly and indirectly with the interested entity unlike the most commercial mobile script generators.