• 교육시설 논문지
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• 제21권2호
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• pp.25-32
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• 2014

Many Korean university campuses are located on hilly terrain where the hierarchy of the path system is unclear. Therefore, it is difficult to analyze the pedestrian network through space syntax, in which only horizontal direction changes are considered as depths of space. The purpose of this study is to compare pedestrian movement patterns and space syntax analysis in order to find their relevance to each other and the relationship between them. We conducted a survey regarding the most-visited buildings and pathways at S-University, which is located on a hilly area in Seoul. The survey results were compared with the Space Syntax integration map by regression analysis. For the segments where the relationship between pedestrian volume and integration was weak, field observations were conducted. As a result, topographical aspects, functional aspects, and location aspects were observed as the main influential factors. In addition, the research proposes that adding an extra axial line per vertical directional change can potentially compensate for the low relevance of stairs. This study suggests the possibility and the necessity of three-dimensional space syntax programs and emphasizes the importance of campus planning for the pedestrian environment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권10호
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• pp.3851-3866
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• 2015

The dynamic nature of opportunistic networks results in long delays, low rates of success for deliveries, etc. As such user experience is limited, and the further development of opportunistic networks is constrained. This paper proposes a prediction-based routing method for opportunistic networks (PB-OppNet). Firstly, using an ARIMA model, PB-OppNet describes the historical contact information between a node pair as a time series to predict the average encounter time interval of the node pair. Secondly, using an optimal stopping rule, PB-OppNet obtains a threshold for encounter time intervals as forwarding utility. Based on this threshold, a node can easily make decisions of stopping observing, or delivering messages when potential forwarding nodes enter its communication range. It can also report different encounter time intervals to the destination node. With the threshold, PB-OppNet can achieve a better compromise of forwarding utility and waiting delay, so that delivery delay is minimized. The simulation experiment result presented here shows that PB-OppNet is better than existing methods in prediction accuracy for links, delivery delays, delivery success rates, etc.

• Advances in Computational Design
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• 제8권3호
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• pp.237-253
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• 2023

Torque ripple content and variable switching frequency operation of conventional direct torque control (DTC) are reduced by the integration of space vector modulation (SVM) into DTC. Integration of space vector modulation to conventional direct torque control known as SVM-DTC. It had been more frequently used method in renewable energy and machine drive systems. In this paper, SVM-DTC is used to control the rotor side converter (RSC) of a wind driven doubly-fed induction generator (DFIG) because of its advantages such as reduction of torque ripples and constant switching frequency operation. However, flux and torque ripples are still dominant due to distorted current waveforms at different operations of the wind turbine. Therefore, to smoothen the torque profile a Neural Network Controller (NNC) based SVM-DTC has been proposed by replacing the PI controller in the speed control loop of the wind turbine controller. Also, stability analysis and simulation study of DFIG using process reaction curve method (RRCM) are presented. Validation of simulation study in MATLAB/SIMULINK environment of proposed wind driven DFIG system has been performed by laboratory developed prototype model. The proposed NNC based SVM-DTC yields superior torque response and ripple reduction compared to other methods.

• International Journal of Computer Science & Network Security
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• 제24권4호
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• pp.11-25
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• 2024

The proliferation of IoT devices has presented an unprecedented challenge in managing device identities securely and efficiently. In this paper, we introduce an innovative Hybrid Blockchain-Based Approach for IoT Identity Management that prioritizes both security and efficiency. Our hybrid solution, strategically combines the advantages of direct and indirect connections, yielding exceptional performance. This approach delivers reduced latency, optimized network utilization, and energy efficiency by leveraging local cluster interactions for routine tasks while resorting to indirect blockchain connections for critical processes. This paper presents a comprehensive solution to the complex challenges associated with IoT identity management. Our Hybrid Blockchain-Based Approach sets a new benchmark for secure and efficient identity management within IoT ecosystems, arising from the synergy between direct and indirect connections. This serves as a foundational framework for future endeavors, including optimization strategies, scalability enhancements, and the integration of advanced encryption methodologies. In conclusion, this paper underscores the importance of tailored strategies in shaping the future of IoT identity management through innovative blockchain integration.

• 대한전자공학회논문지TC
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• 제43권11호
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• pp.16-24
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• 2006

본 논문에서는 서비스 통합 모델에 적용할 수 있는 유비쿼터스 헬스케어 시스템을 설계한다. 이것은 댁내 및 댁외에서 사용자의 체지방, 혈압, 운동량, SPO2의 건강정보를 측정하기 위한 센서 모듈과 데이터 수집 장치로 무선 센서 네트워크를 구성하였고, 사용자의 인증과 보안, VOD 서비스 등과의 연동을 위해 서비스 통합 서버를 구성하였고, 사용자의 건강정보를 실시간으로 수집, 진단하여 사용자의 건강 상태나 위급 상황을 의사나 보호자에게 알리도록 하는 헬스케어 서버를 구성하야 헬스케어 시스템을 구현하였다.

• 한국융합학회논문지
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• 제8권2호
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• pp.15-20
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• 2017

본 논문에서는 Esp8266 모듈과 Node.js, TCP/IP 소켓 통신을 이용하여 소형경량 데이터 통합장치를 설계하였다. 본 장치는 Wifi연결 기능을 지원하는 Esp8266모듈을 사용하여 서버와 클라이언트를 구성하고, TCP/IP의 소켓 통신을 사용하여 양방향 데이터 전송을 지원하도록 구성하였다. 서버는 Node.js 운영체제를 사용하여 구성하고 Mysql을 사용하여 데이터를 통합할 수 있게 하였으며, 네트워크는 홈 네트워크와 같이 공유기를 중심으로 사설 IP를 부여하여 Esp8266이 각각 독립적인 IP를 가지게 설계하였다. 본 장치는 양방향으로 데이터를 전송 할 수 있고, 서버 측에서 각각의 클라이언트 데이터들을 저장할 수 있으며 또한 Wire-Shark를 통해 양방향으로 전송되어지는 데이터의 흐름을 확인할 수 있어서 소형의 실시간 데이터 통합 및 융합 장치로 활용할 수 있다.

• International Journal of Computer Science & Network Security
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• 제23권12호
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• pp.194-198
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• 2023

The current electricity networks will undergo profound changes in the years to come to be able to meet the growing demand for electricity, while minimizing the costs of consumers and producers, etc. The electricity network of tomorrow or even the intelligent « Smart Grids » network will be the convergence of two networks: the electricity network and the telecommunications network. In this context falls our work which aims to study the impact of the integration of energy decentralization into the electricity network. In this sense, we have implemented a new smart grid model where several coexisting suppliers can exchange information with consumers in real time. In addition, a new approach to energy distribution optimization has been developed. The simulation results prove the effectiveness of this approach in improving energy exchange and minimizing consumer purchase costs and line losses.

• 한국기계가공학회지
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• 제14권3호
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• pp.15-20
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• 2015

After the US government declared 3D printing technology a next-generation manufacturing technology, there have been many practical studies conducted to expand 3D printing technology to manufacturing technologies, called AMERICA MAKES. In particular, the Keck Center, located at the University of Texas at El Paso, has studied techniques for easily combing the 3D stacking process with space mobility and expanded these techniques to simultaneous staking techniques for multiple materials. Additionally, it developed convergence manufacturing techniques, such as direct inking techniques, in order to produce a module structure that combines electronic circuits and components, such as CUBESET. However, in these studies, it is impossible to develop a unified system using traditional independent through simple sequencing connections. This is because there are many problems in the integration between the stacking modeling of 3D printers and post-machining, such as thermal deformations, the precision accuracy of 3D printers, and independently driven coordinate problems among process systems. Therefore, in this paper, the integration method is suggested, which combines these 3D printers and subsequent machining process systems through an Internet-based cloud. Additionally, the sequential integrated system of a 3D printer, an NC milling machine, machine vision, and direct inking are realized.

• 조명전기설비학회논문지
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• 제17권4호
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• pp.64-73
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• 2003

빌딩자동제어시스템은 여러 서브시스템의 통합을 통한 고도의 서비스 제공, 관리비의 절감 등을 효과적으로 실현할 수 있다. 통합운전의 전제조건은 표준 프로토콜을 가진 개방형 네트워크를 이용하여 합리적인 네트워크 설계에 있다. 따라서 본 논문에서는 BAS에 가장 걸림돌이 되었던 화재경보시스템(소방법 명칭)을 ANSI/FIA 709.1인 LonTalk 프로토콜을 이용하여 BAS에서의 통합을 위한 개념적인 새로운 설계방안을 제시하였다. 기존 시스템에서 사용되는 중계기를 대체하는 지능형제어모듈을 개발하고 이를 이용하여 개방된 지능형 화재경보시스템의 설계방안을 제안한 것이다. 이는 오보률의 저감 실현은 물론 빌딩의 통합운전에도 크게 기여할 것으로 판단된다.

• International Journal of Computer Science & Network Security
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• 제21권12호
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• pp.356-364
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• 2021

In the formation of a socially oriented economy in the context of European integration, the development of tourism is one of the priority areas that positively affects the socio-economic situation of the country as a whole and its regions in particular, stimulates important economic activities and strengthens Ukraine's positive image in Europe and the world. In view of this, in the framework of a thorough study of the tourism industry it is necessary to assess its potential. This study proposes an assessment of tourism potential in the regional context, which consists of consistent implementation of six steps, namely: first, the definition of research objects for which the tourism potential is determined; secondly, the formation of a set of basic features for assessing tourism potential of certain objects; thirdly, the collection of information on individual indicators, which are selected to assess the tourism potential of the objects; fourth, the calculation of parametric indices by comparing the indicators of each individual object of study (region) with the average values in the set of objects under study; fifth, the definition of a generalized index of tourism potential of the region; sixth, grouping regions by the values of the generalized index of tourism potential. Execution of the stated algorithm involves the use of various methods, in particular, statistical, graphical, parametric, the analysis of hierarchies, matrix and cartographic. Approbation of the proposed assessment of tourism potential at the regional level in Ukraine allowed to group regions according to the values of the generalized index of tourism potential, which can be used as a basis for developing measures to increase and enhance their tourism potential in Ukraine in terms of European integration.