• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.284-287
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• 2020

현재 자율주행은 Stand Alone 으로 차량 자체적인 센서만을 이용해서 자율주행을 하고 있다. 이번 연구로 Stand Alone 하지 않은 서버 제어 방식의 자율주행 차량 개발이 가능해져 자율주행 차량의 센서와 연산장치가 줄어 차량의 가격이 줄어들며 이 시스템의 궁극적 목표인 자율주행 차량의 사고 감소에 큰 도움을 줄 것을 기대한다.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.703-709
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• 2023

It is most desirable to train with a real crane in an environment similar to that of a port for crane operation training in charge of loading and unloading in a port, but it has time and space limitations and cost problems. In order to overcome these limitations, VR(Virtual Reality) based crane training programs and related devices are receiving a lot of attention. In this paper, we designed and implemented a VR-based harbor crane simulator operating on an HMD. The simulator developed in this paper consists of a crane simulator program that operates on the HMD, an IoT driving terminal that processes trainees' crane operation input, and a training server that stores trainees' training information. The simulator program provides VR-based crane training scenarios implemented with Unity3D, and the IoT driving terminal developed based on Arduino is composed of two controllers and transmits the user's driving operation to the HMD. In particular, the crane simulator in this paper uses a training server to create a database of environment setting values for each educator, progress and training time, and information on driving warning situations. Through the use of such a server, trainees can use the simulator in a more convenient environment and can expect improved educational effects by providing training information.

• Journal of Internet of Things and Convergence
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• v.7 no.2
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• pp.47-53
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• 2021

In order to transmit video data stored in servers with limited bandwidth in IoT environments to many clients, a transmission plan must be established by considering factors such as the number of transmission rate changes, peak transmission rate, and transmission rate changes. This transmission plan is called smoothing, and includes CBA that minimizes the number of transmission rate increases, MCBA that minimizes the number of transmission rate changes, and MVBA to minimize the transmission rate changes. In this work, to evaluate the performance of the proposed algorithm[16], we compare the proposed algorithm with the existing smoothing algorithms with the peak rate, the number of transmission rate changes, the rate increase, the peak rate utilization, and the average transmission rate with various video data and buffer sizes. The evaluation results show that the proposed algorithm helps to efficiently use the server's finite network resources by establishing a transport plan with the lowest average transfer rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.46-54
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• 2018

The Internet of Things (IoT) is an environment in which various devices provide services to users through communications. Because of the nature of the IoT, data are stored and distributed in heterogeneous information systems. In this situation, IoT end applications should be able to access data without having information on where the data are or what the type of storage is. This mechanism is called Service Discovery (SD). However, some problems arise, since the current SD architectures search for data in physical devices. First, turnaround time increases from searching for services based on physical location. Second, there is a need for a data structure to manage devices and services separately. These increase the administrator's service configuration complexity. As a result, the device-oriented SD structure is not suitable to the IoT. Therefore, we propose an SD structure called Name-based Service-centric Service Discovery (NSSD). NSSD provides name-based centralized SD and uses the IoT edge gateway as a cache server to speed up service discovery. Simulation results show that NSSD provides about twice the improvement in average turnaround time, compared to existing domain name system and distributed hash table SD architectures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.602-608
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• 2020

Development of Internet technology and the spread of various smart devices provide a convenient computing environment for people, which is becoming common thanks to the Internet of Things (IoT). However, attacks by hackers have caused various problems, such as leaking personal information or violating privacy. In the IoT environment, various smart devices are connected, and network attacks that are used in the PC environment are occurring frequently in the IoT. In fact, security incidents such as conducting DDoS attacks by hacking IP cameras, leaking personal information, and monitoring unspecified numbers of personal files without consent are occurring. Although attacks in the existing Internet environment are PC-oriented, we can now confirm that smart devices such as IP cameras and tablets can be targets of network attacks. Through performance evaluation, the proposed protocol shows 11% more energy efficiency on servers than RSA, eight times greater energy efficiency on clients than Kerberos, and increased efficiency as the number of devices increases. In addition, it is possible to respond to a variety of security threats that might occur against the network. It is expected that efficient operations will be possible if the proposed protocol is applied to the IoT environment.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.01a
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• pp.239-242
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• 2015

CoAP은 IoT(Internet of Things, 사물인터넷)를 위해 설계된 HTTP 메카니즘을 기반의 응용 계층 프로토콜로 M2M 통신을 위해 만들어 졌다. 이로 인해 WSN과 같은 제한적인 환경에서의 전송과 프로세싱을 효율적으로 처리 할 수 있고, CoAP과 HTTP사이의 맵핑 또한 가능하다. 본 논문에서는 HTTP 클라이언트가 CoAP 서버 혹은 CoAP 클라이언트가 HTTP 서버에게 직접적인 연결을 제공하는 방안을 제시한다. 또한, 전력 수급에 제한이 있어 데이터 전송률을 최소화 할 필요가 있기 때문에 캐싱을 사용한다. 제안하는 방안의 성능을 수학적 모델링을 통해 평가, 분석한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.779-780
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• 2016

해당 개발 연구기기는 스마트그리드와 같은 에너지 IoT에 적용할 수 있는 다중통신기반 게이트웨이로 정보를 수집하는 무선 구간과 이를 상위 서버로 전달하는 무선 또는 유선 구간을 복합적으로 적용한 장치이다. 에너지를 효율적으로 관리하는 시스템 구축에 있어 여러 정보를 수집하고 상위 관리 서버로 전달하는 중요 역할을 담당한다. 현재는 연구단계로 정보 수집 및 전달은 시험을 완료하였으며, 성능 개선을 진행 중에 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.839-842
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• 2016

최근 사물인터넷에 대한 관심과 투자가 크게 증가하고 있으나 보안 측면에서 문제가 지속적으로 제기되고 있다. 그 해결책으로서 기업에서는 기업 내에서 구현한 클라이언트와 서버들로만 구성되어진 자체 IoT 생태계를 구축하고 있다. 그러나 이러한 방식의 단점으로는 다양한 서드파티 어플리케이션이 해당 IoT 서버들의 자원을 활용할 수 없다는 것이다. 따라서 본 논문에서는 이를 보안한 OAuth 2.0 기반 CoAP 인증 프레임워크의 설계를 제안한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.570-572
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• 2016

Recent people start to attention about IoT(Internet of Things) and applying IoT on many fields is rising. In this paper we have implemented to control things via web so we used SimpleHTTPServer with Python. Client was used POST, one of web request method which passes through web server and developed a remote control system.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.569-571
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• 2015

본 논문에서는 IoT(Internet of Things) 표준 프로토콜인 IETF(Internet Engineering Task Force) CoAP(Constrained Application Protocol)을 이용한 실내 자원 제어 구조를 제시한다. 제안한 웹 기반 실내 환경 제어 구조에서는 웹 서버에 프록시(proxy)와 자원 디렉토리(RD : Resource Directory) 기능을 포함하고 있다. 이를 통해 CoAP 프로토콜을 통해 저전력, 소규모의 노드를 웹 서버에 등록하고, 프록시의 HTTP과 CoAP 메시지 변환 기능을 이용하여 사용자가 웹브라우즈를 이용하여 실내 환경을 제어할 수 있다.