• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.6
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• pp.1179-1194
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• 1992

QUICKER scheme has several attractive properties. However, under highly convective conditions, it produces overshoots and possibly some oscillations on each side of steps in the dependent variable when the flow is convected at an angle oblique to the grid line. Fortunately, it is possible to modify the QUICKER scheme using non-linear and linear functional relationship. Details of the development of polynomial upwinding scheme are given in this paper, where it is seen that this non-linear scheme has also third order accuracy. This polynomial upwinding scheme is used as the basis for the SHARPER and SMARTER schemes. Another revised scheme was developed by partial modification of QUICKER scheme using CDS and UPWIND schemes(QUICKUP). These revised schemes are tested at the well known bench mark flows, Two-Dimensional Pure Convection Flows in Oblique-Step, Lid Driven Cavity Flows and Buoyancy Driven Cavity Flows. For pure convection oblique step flow test problem, QUICKUP, SMARTER and SHARPER schemes remain absolutely monotonic without overshoot and oscillation. QUICKUP scheme is more accurate than any other scheme in their relative accuracy. In high Reynolds number Lid Driven Cavity Flow, SMARTER and SHARPER schemes retain lower computational cost than QUICKER and QUICKUP schemes, but computed velocity values in the revised schemes produced less predicted values than QUICKER scheme which is strongly effected by overshoot and undershoot values. Also, in Buoyancy Driven Cavity Flow, SMARTER, SHARPER and QUICKUP schemes give acceptable results.

• Journal of computational fluids engineering
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• v.2 no.1
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• pp.73-83
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• 1997

이 논문은 최근에 개발된 네가지 종류의 고차 유계 대류항 처리법인 SOUCUP, HLPA, SMARTER 그리고 COPLA 해법들을 비교 분석한다. 모든 해법들을 실제적인 공학적인 문제에의 적용을 위하여 비균일, 비직교 좌표에 공식화 하였다. 해법들의 상대적인 검증을 위하여 여러 가지 종류의 시험 문제들에 적용하여 검증하였다. 수치실험의 결과는 시험한 4종류의 해법들이 유계성을 만족하고 고차 해법의 정확도를 유지하는 것으로 나타났다. HLPA, SMARTER와 COPLA 해법들은 거의 같은 정도의 해의 정확성을 보였으며, SCOCUP 해법은 조금 부정확한 것으로 나타났다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.8
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• pp.2083-2100
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• 2023

The rise of Industry 5.0 has led to a smarter and more digital way of doing business, but with it comes the issue of user privacy and security. Only when privacy and security issues are addressed, will users be able to transact online with greater peace of mind. Thus, to address the security and privacy problems associated with industry blockchain technology, we propose a privacy protection scheme for online financial transactions based on verifiable ring signatures and blockchain by comparing and combining the unconditional anonymity provided by ring signatures with the high integrity provided by blockchain technology. Firstly, we present an algorithm for verifying ring signature based on distributed key generation, which can ensure the integrity of transaction data. Secondly, by using the block chain technique, we choose the proxy node to send the plaintext message into the block chain, and guarantee the security of the asset transaction. On this basis, the designed scheme is subjected to a security analysis to verify that it is completely anonymous, verifiable and unerasable. The protection of user privacy can be achieved while enabling online transactions. Finally, it is shown that the proposed method is more effective and practical than other similar solutions in performance assessment and simulation. It is proved that the scheme is a safe and efficient online financial transaction ring signature scheme.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.1-9
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• 2011

Nowadays it is necessary to replace electrical wires with another intelligent connection method because the consumers, who have much experience with mobile smart devices, are expecting easier and smarter connectivity in their home electronics such as wireless linking. In this paper a bidirectional CEC control scheme is newly proposed to expand the controllability from one to two way in a millimeter band image transmission system because two degree of freedom controllability presents more intelligent convenience in HDMI interface systems. Experimental study shows the feasibility of the proposed system as an advanced image transmission solution in millimeter band including an intelligent 2 DOF CEC interface with the performance result of 3.0 Gbps transmission band for 1080p full-HD image steaming.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.4
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• pp.418-423
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• 2014

Intelligent Transportation Systems (ITS) are advanced applications which, without embodying intelligence as such, aim to provide innovative services relating to different modes of transport and traffic management and enable various users to be better informed and make safer, more coordinated, and 'smarter' use of transport networks. However, ITS has the different size and shapes according to the city environment policy to adjust the city scene and it has to be displayed by different message on the information display device in real-time. And the information service providers must make the information display system which has the different information and data each time. That is very time and workers consuming and auto message frame generation system is necessary. In this paper, we design and develop the message frame generation system which can set several parameters easily for the generation of the message frame automatically on the windows environment and we do not need to go the field to get the test data.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.183-183
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• 2023

Smart water cities (SWC) are urban municipalities that utilizes modern innovations in managing and preserving the urban water cycle in the city; with the purpose of securing sustainability and improving the quality of life of the urban population. Understanding the different urban water characteristics and management strategies of cities situate a baseline in the development of evaluation scheme in determining whether the city is smart and sustainable. This research herein aims to develop measurements and evaluation for SWC Key Performance Indicators (KPIs), and set up a unified global standard and certification scheme. The assessment for SWC is performed in technical, as well as governance and prospective aspects. KPI measurements under Technical Pillar assess the cities' use of technologies in providing sufficient water supply, monitoring water quality, strengthening disaster resilience, minimizing hazard vulnerability, and maintaining and protecting the urban water ecosystem. Governance and Prospective Pillar on the other hand, evaluates the social, economic and administrative systems set in place to manage the water resources, delivering water services to different levels of society. The performance assessment is composed of a variety of procedures performed in a quantitative and qualitative manner, such as computations through established equations, interviews with authorities in charge, field survey inspections, etc. The developed SWC KPI measurements are used to evaluate the urban water management practices for Busan Eco Delta city, a Semulmeori waterfront area in Gangseo district, Busan. The evaluation and scoring process was presented and established, serving as the basis for the application of the smart water city certification all over the world. The established guideline will be used to analyze future cities, providing integrated and comprehensive information on the status of their urban water cycle, gathering new techniques and proposing solutions for smarter measures.