• International journal of advanced smart convergence
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• 제9권2호
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• pp.157-163
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• 2020

Recently the blockchain technology has been actively studied due to its great potentiality. The smart contract is a key mechanism of the blockchain system. Due to the short history of the smart contract, many issues have not been solved yet. One main issue is vulnerability and another main issue is cost optimization. While the vulnerability of smart contract has been actively studied, the cost optimization has been rarely studied. In this paper, we propose two cost optimization methods for smart contracts running on the blockchain system. Triggering a function in a smart contract program code may require costs and it is repeated continuously. So the minimization of costs required to trigger a function of smart contract while maintaining the performance equally is very important. The proposed two methods minimize the usage of expensive permanent variables deployed on the blockchain system. We apply the proposed two methods to three prevalent blockchain platforms: Ethereum, Klaytn and Tron. Evaluation experiments verify that the proposed scheme significantly reduces the costs of functions in the smart contract written with Solidity.

• International Journal of Computer Science & Network Security
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• 제22권2호
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• pp.139-144
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• 2022

The smart cities are evolving constantly and are responsible for the current transformation of cities and countries into a completely connected network of information and technology This interconnected network of a huge number of smart devices is capable of exchanging complex information and provides tremendous support including enhanced quality of life within urban locations. Unfortunately this set-up is vulnerable to security attacks and requires the widespread ubiquitous network to authorize access through privacy and thus offer security in order to ensure civilian participation in a country. The smart network should benefit the individuals of the country by developing potential strategies to protect the smart cities and their participating entities from the unauthorized attacks. Trustworthy data sharing strategies based on the utilization of advanced technology features via smart communication network could solve some issues of privacy and security. This paper presents the challenges and issues related to protection and highlights the important aspects of securing the smart cities and its components. It also presents the role of cloud security for building a secure smart city.

• 디지털융복합연구
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• 제9권5호
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• pp.99-111
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• 2011

오늘날 SNS를 포함하여 다양한 스마트미디어들의 급속한 보급으로 새로운 스마트융합시대가 도래하고 있다. 그러나 이러한 스마트융합사회가 아직 효율적이지는 못하다. 특히 장시간의 로딩시간, 비싼 단말기와 이용료, 개인정보의 유출, 스팸메일과 음란폭력물, 잦은 끊김, 접속 장애, 정보격차 등 무수한 이용의 어려움 들이 아직 해결되지 못하고 있다. 이러한 문제점들은 당연히 방송통신 정책의 과제가 될 것이다. 이러한 관점에서 본 논문은 보다 효율적인 스마트융합사회를 만들기 위하여 역동적인 삶의 질에 기초한 방송통신 정책들을 제안하고 있다. 이러한 정책들은 새로운 방송통신 콘텐츠의 개발과 생산 그리고 안정적인 서비스의 제공과 프라이버시의 보호 등 지금까지 제기되는 정책적 과제들을 해결하는데 크게 기여할 수 있는 내용들이다.

• 디지털융복합연구
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• 제11권3호
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• pp.33-40
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• 2013

스마트폰, 스마트TV, 태블릿PC 등 스마트 기기의 보급으로 이러한 매체를 통해 제공되는 스마트광고가 확산되고 있다. 하지만 이러한 스마트광고도 기존 광고의 틀에 얽메여 스마트 기기의 발전만큼 빠른 광고 기술의 발전을 보여주지 못하고 있다. 이러한 관점에서 본 연구는 스마트광고의 활용 현황과 문제점 등의 분석을 통하여 스마트광고의 활성화 방안 등을 모색하고 있다. 현재 현업에서 가장 활발하게 이용되고 있는 스마트광고는 VOD광고, QR코드광고, SNS광고, 검색광고 등이다. 스마트광고의 문제점 및 개선점으로는 비합리적 효과측정 및 과금 체계, 광고의 표준화와 성공적인 수익 모델의 부재, 신뢰성 확보 문제, 전문 인력의 부족 등으로 지적되었다. 결국 스마트광고의 활성화 방안으로는 광고의 표준화와 과학적 효과측정, 다양한 형태의 광고 개발과 인력 양성, 미국의 IAB와 같은 미디어 랩 설치 등이 필요한 것으로 지적되었다.

• Journal of Information Technology Applications and Management
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• 제20권4호
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• pp.151-164
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• 2013

According to the development of smart technologies such as smart phones, tablet PC, and SNS communication, the necessity of smart work that can change the working environments in organizations has been emphasized. However, while there are many organizations that wish to adopt smart technologies, there are those that have been skeptical until now about its potential success. Leaders may especially have different viewpoints concerning the efficacy and effectiveness of smart work depending on the industries, characteristics of the work, etc. Therefore, this research looks to investigate whether there may be differences between leaders (manager, project manager, supervisor, etc.) and non-leaders (team member, staff, etc.) group in accepting smart working through empirical and exploratory approaches.

• Computers and Concrete
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• 제23권6호
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• pp.399-408
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• 2019

Structural health monitoring is important for the safety of lives and asset management. In this study, numerical models were developed for the piezoresistive behavior of smart concrete based on finite element (FE) method. Finite element models were calibrated with experimental data collected from compression test. The compression test was performed on smart concrete cube specimens with 75 mm dimensions. Smart concrete was made of cement CEM II 42.5 R, silica fume, fine and coarse crushed limestone aggregates, brass fibers and plasticizer. During the compression test, electrical resistance change and compressive strain measurements were conducted simultaneously. Smart concrete had a strong linear relationship between strain and electrical resistance change due to its piezoresistive function. The piezoresistivity of the smart concrete was modeled by FE method. Twenty-noded solid brick elements were used to model the smart concrete specimens in the finite element platform of Ansys. The numerical results were determined for strain induced resistivity change. The electrical resistivity of simulated smart concrete decreased with applied strain, as found in experimental investigation. The numerical findings are in good agreement with the experimental results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권8호
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• pp.3958-3971
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• 2016

With Internet of Things (IoT) technology, home environment becomes smarter than ever. Not only smart devices such as smart phone or smart TV, but also various IoT devices including sensor, smart thermostat, and smart scale has now become very common on the market. These devices have connectivity to the Internet, so that user can read data from the device or control the device using Internet technology. However, due to diversity of smart home requirements, device collaboration in smart home remains a challenging task still. Usually smart home is built with various technologies to fulfill its own purpose, and these purposes cover very wide area from controlling low-power sensor devices to controlling high-performance devices like smart TV and smart phone. This variety of smart home requirements makes smart home very complicated due to mixed network architecture, protocol and technology. In this paper, a framework to enable managing and collaborating heterogeneous IoT devices in smart home environment is proposed. Several programming models are defined in the proposed framework to make application development for heterogeneous devices more intuitive. The proposed framework has been implemented as a web service, and a case study with real-world smart home IoT devices is presented.

• 한국융합학회논문지
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• 제10권7호
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• pp.33-37
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• 2019

스마트 폰을 비롯한 스마트 TV 등 여러가지 스마트 기기의 보급으로 인해 스마트 기기 간의 연동에 대한 필요성이 증대되고 있다. 본 논문에서는 스마트 TV와 스마트 폰을 연동하기 위한 게임 프레임워크를 제시하고, 시범 콘텐츠를 통해 제시된 프레임워크의 효용성을 증명하였다. 스마트 기기 사이의 연결 문제는 기본적으로 이기종 간의 연결 문제로 볼 수 있다. 이러한 문제는 이기종 기기 사이의 데이터 송수신과 보안까지 고려해야 하기 때문에, 핵심적인 데이터는 클라우드 컴퓨팅 개념을 도입하여 서버에 저장하고 스마트TV에서는 이 데이터를 이용해 게임을 수행하는 형태로 작동한다. 제시된 프레임워크는 게임을 비롯한 여러 가지 관련 분야에 적용될 것으로 예상된다.

• 한국구조물진단유지관리공학회 논문집
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• 제11권2호
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• pp.134-144
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• 2007

본 연구에서는 구조물의 모니터링 시스템을 위하여 최근에 급속하게 발전하는 스마트 센서 기술을 이용하여 스마트 센서 장치를 개발하였고 다양한 실험을 통하여 개발한 스마트 센서의 기본적 성능 평가와 모형 구조물을 이용한 손상 검출 실험을 실시하였다. 본 논문은 Part 1로써 스마트 센서의 개발과 성능 평가에 관한 것이고 Part 2에서는 스마트 센서를 이용한 손상 검출 결과를 유선 계측 시스템을 이용한 실험결과와 비교하였다. 스마트 센서는 고 출력의 무선 모뎀과 고 성능 MEMS 센서, AVR 마이크로컨트롤러를 이용하여 개발하였으며 센서의 제어와 운영을 위한 임베디드 프로그램을 개발하였다. 스마트 센서의 성능을 검증하기 위하여 민감도와 분해능 분석 실험과 캔틸레버 보와 가진기를 이용한 데이터 획득 실험, 실 구조물을 이용한 현장 적용 실험을 실시하였다. 실험 결과, 개발한 스마트 센서의 성능에 대한 만족스런 결과를 얻었다.

• Smart Structures and Systems
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• 제4권3호
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• pp.367-389
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• 2008

Shape Memory Alloys (SMAs) are unique materials with a paramount potential for various applications in bridges. The novelty of this material lies in its ability to undergo large deformations and return to its undeformed shape through stress removal (superelasticity) or heating (shape memory effect). In particular, Ni-Ti alloys have distinct thermomechanical properties including superelasticity, shape memory effect, and hysteretic damping. SMA along with sensing devices can be effectively used to construct smart Reinforced Concrete (RC) bridges that can detect and repair damage, and adapt to changes in the loading conditions. SMA can also be used to retrofit existing deficient bridges. This includes the use of external post-tensioning, dampers, isolators and/or restrainers. This paper critically examines the fundamental characteristics of SMA and available sensing devices emphasizing the factors that control their properties. Existing SMA models are discussed and the application of one of the models to analyze a bridge pier is presented. SMA applications in the construction of smart bridge structures are discussed. Future trends and methods to achieve smart bridges are also proposed.