• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제16권5호
• /
• pp.1687-1707
• /
• 2022

With the development of multiuser online meetings, more group-oriented technologies and applications for instance collaborative work are becoming increasingly important. Authenticated Group Key Agreement (AGKA) schemes provide a shared group key for users with after their identities are confirmed to guarantee the confidentiality and integrity of group communications. On the basis of the Public Key Cryptography (PKC) system used, AGKA can be classified as Public Key Infrastructure-based, Identity-based, and Certificateless. Because the latter type can solve the certificate management overhead and the key escrow problems of the first two types, Certificateless-AGKA (CL-AGKA) protocols have become a popular area of research. However, most CL-AGKA protocols are vulnerable to Public Key Replacement Attacks (PKRA) due to the lack of public key authentication. In the present work, we present a CL-AGKA scheme that can resist PKRA in order to solve impersonation attacks caused by those attacks. Beyond security, improving scheme efficiency is another direction for AGKA research. To reduce the communication and computation cost, we present a scheme with only one round of information interaction and construct a CL-AGKA scheme replacing the bilinear pairing with elliptic curve cryptography. Therefore, our scheme has good applicability to communication environments with limited bandwidth and computing capabilities.

• Journal of Information Processing Systems
• /
• 제19권3호
• /
• pp.334-346
• /
• 2023

An electronic document based on PDF has been widely used in customer communication between an enterprise and a customer to deliver personalized content. However, electronic documents based on PDF in the form of paper layouts are not suitable for mobile environments because of low readability and lack of interactive interaction. Even though HTML is an essential language in a mobile environment, electronic document based on PDF is still used as it has a content integrity verification feature with a digital signature. It means that a user is sacrificing user experience in a mobile environment for content integrity and using paper-layout electronic documents. In this research, we design the Document HTML specification by setting the Document HTML conformance, adding the extended meta tags, and signing the message digest with a digital signature based on public key infrastructure (PKI). Furthermore, we implemented the Document HTML system, which has REST API services to generate and verify the Document HTML, and did experimental verification of the theory. As a result, we have confirmed that the Document HTML has both content integrity and user experience on mobile. Furthermore, the Document HTML is expected to be an alternative document format to deliver personalized content from an enterprise to a customer in a mobile environment instead of the paper layout electronic document such as PDF.

• 한국인터넷방송통신학회논문지
• /
• 제13권1호
• /
• pp.229-234
• /
• 2013

스마트폰의 보급과 위치 기반 서비스의 활성화로 스마트폰을 기반으로 하는 위치정보 서비스의 필요성과 중요성이 매우 중요해지고 있다. 그러나 기존의 방법들은 경제성이나 편의성, 정확도의 부족으로 실용화가 어려운 상황이며, 무선랜의 신호세기를 이용한 방법은 정확도가 떨어지는 문제가 있다. 본 논문에서는 스마트폰의 음향신호와 블루투스 통신 방식을 이용한 상대위치 인식 기술에 대한 기술적 배경과 구현 기술 및 측정 결과에 대해 기술하였다. 이 기술은 저렴한 구현 비용의 단일 장치로 스마트폰의 정밀한 측위가 가능하며, 특히 실내에서의 위치기반 지능화 서비스에 적합하다.

• 한국인터넷방송통신학회논문지
• /
• 제18권3호
• /
• pp.167-175
• /
• 2018

IT 기술의 급격한 발전에도 불구하고 여전히 시각장애인들은 보행보조 도구로써 단순한 형태의 지팡이를 사용하고 있으며 보다 발전된 보행보조 도구를 필요로 하고 있다. 인터넷 서비스 및 센서를 기반으로 개발된 스마트케인은 이러한 시각장애인들에게 주변정보 및 보행상황을 음성과 진동으로 전달함으로써 기존 시각장애인용 지팡이에 비해 높은 안전성과 편의성을 제공할 수 있다. 본 논문에서는 기존에 연구개발 되었던 스마트케인보다 사용자 편의가 고려된 실용적인 제품을 개발하기 위해 초음파를 이용한 거리측정에서 보다 먼 거리를 측정할 수 있고 음파의 반향파라는 특성으로 생기는 오차의 결과를 최적화 할 수 있는 알고리즘을 기반으로 거리 알람 신호를 촉각으로 전달하고 GPS 정보를 이용하여 현재 위치를 음성으로 알리는 동시에 인체 공학적인 형태로 디자인되어 사용자 친화적인 발전된 형태의 스마트케인을 제안하고 구현한다.

• Journal of Communications and Networks
• /
• 제9권4호
• /
• pp.457-465
• /
• 2007

Native information provider(IP) anycast suffers from routing scalability issues and the lack of stateful communication support. For this reason, we propose architecture for scalable and transparent anycast services(ASTAS), a proxy-based architecture that provides support for stateful anycast communications, while retaining the transparency offered by native anycast. Dynamic resource assignment for each initiated session guarantees that a connection is established with the most suitable target server, based on network and server conditions. Traffic engineering in the overlay can be realized in an effective way due to the dissemination of aggregated state information in the anycast overlay. To minimize the total deployment cost for ASTAS architectures, we propose optimized proxy placement and path finding heuristics based on look-ahead information gathered in network nodes. Contrary to a regular integer linear program(ILP) formulation, these heuristics allow to optimize proxy placement in large networks. A use case on a European reference network illustrates that lower proxy costs enable proxy deployment closer to the end-users, resulting in a reduced network load.

• 전기학회논문지
• /
• 제64권3호
• /
• pp.375-383
• /
• 2015

The virtual power plant (VPP) is a new technology to achieve flexibility as well as controllability, like traditional centralized power plants, by integrating and operating different types of distributed energy resources (DER) with the information communication technology (ICT). Though small-sized DERs may not be controlled in a centralized manner, these are more likely to be utilized as power plants for centralized dispatch and participate in the energy trade given that these are integrated into a unified generation profile and certain technical properties such as dispatch schedules, ramp rates, voltage control, and reserves are explicitly implemented. Unfortunately, the VPP has been in a conceptual stage thus far and its common definition has not yet been established. Such a lack of obvious guidelines for VPP may lead to a further challenge of coming up with the business model and reinforcing the investment and technical support for VPP. In this context, this paper would aim to identify the definition of VPP as a critical factor in smart grid and, at the same time, discuss the details required for VPP to actively take part in the electricity market under the smart grid paradigm.

• Journal of Information Processing Systems
• /
• 제13권4호
• /
• pp.703-715
• /
• 2017

Mammogram images are sensitive in nature and even a minor change in the environment affects the quality of the images. Due to the lack of expert radiologists, it is difficult to interpret the mammogram images. In this paper an algorithm is proposed for a computer-aided diagnosis system, which is based on the wavelet based adaptive sigmoid function. The cascade feed-forward back propagation technique has been used for training and testing purposes. Due to the poor contrast in digital mammogram images it is difficult to process the images directly. Thus, the images were first processed using the wavelet based adaptive sigmoid function and then the suspicious regions were selected to extract the features. A combination of texture features and gray-level co-occurrence matrix features were extracted and used for training and testing purposes. The system was trained with 150 images, while a total 100 mammogram images were used for testing. A classification accuracy of more than 95% was obtained with our proposed method.

• 통합자연과학논문집
• /
• 제5권3호
• /
• pp.168-174
• /
• 2012

Gal (1-3) receptors are members of GPCR superfamily with seven transmembrane helices. The neuropeptide galanin mediates its effects through the receptor subtypes Gal1, Gal2, and Gal3 and has been implicated in anxiety and depression related behaviors. Galanin receptors are considered to be important targets for the development of novel antidepressant drugs. Owing to the importance of these receptors, a short communication about the sequential and structural studies about the functional Galanin (1-3) receptors has been reported. Structural studies have been hampered due to the lack of X-ray crystal structures. However with the availability of templates with close homologs comparative modeling could be encouraging. Sequence analysis was done for each receptors and homology modeling of each receptors were done with recently reported templates. Comparative analyses were done between these receptors to identify the relationships between them sequentially. Phylogram was generated between these receptors to identify the close homologue between this receptor and found that Gal2 and Gal3 receptors are closer. Our results could be useful for further structure based drug design targeting Gal1, Gal2 and Gal3 receptors.

• 한국인터넷방송통신학회논문지
• /
• 제23권2호
• /
• pp.193-199
• /
• 2023

본 논문은 수업 시간에 AR 과학 실험을 활용함으로써 실험 교육의 어려움을 해소하고, 안전사고를 방지하며, 다자간 경험을 통해 몰입도를 극대화하여 능동적 참여를 끌어내는이끌어 내는 것에 목적이 있다. 현재 개발된 교육용 실감형 콘텐츠의 문제는 (1) 수업에서 실질적으로 활용할 수 있는 탐구형 콘텐츠가 없는 문제, (2) 대부분의 애플리케이션이 일회성 콘텐츠로 끝나는 문제, (3) 교사와 학생 간의 상호작용이 불가능한 문제가 있었다. 이러한 문제점을 해결하기 위해 교육과정에 따른 AR 실험을 개발한다. 교사가 학생을 관리할 수 있는 기능을 통해 교사와 학생이 함께 사용할 수 있도록 개발한다.

• 한국식품영양학회지
• /
• 제27권6호
• /
• pp.1078-1089
• /
• 2014

The purpose of this research was to reveal how Jong Ga and its cuisine is perceived by Koreans and foreign tourists and to develop Jong Ga culinary culture for culinary tourism. The Inje Jong Ga was chosen since it is located in Jeonju, Hanok Village, which is a destination for tourists and gourmet enthusiasts. In-depth personal interviews were performed with Koreans and with foreign tourists who were visiting Korea. Interviews were done to provide deeper insight into the comments and subject matters. Most tourists selected "having one table setting for each (Doksang)" as the most distinctive part of Jong Ga and its cuisine. To develop the experience at a Jong Ga as a culinary destination, questionnaires were created to study six areas: preferences on length of stay, price range, food serving style, things to be improved, expectations by as a tourist at a Jong Ga, and the role of the food guide. Perceptions toward Jong Ga and its cuisine were generally positive, but the quality of service and lack of organization in establishments were perceived to be the negative factors.