• ETRI Journal
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• v.39 no.3
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• pp.364-372
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• 2017

For the reliability of controllers in a software defined network (SDN), a dynamic and self-learning schedule method (DSL) is proposed. This method is original and easy to deploy, and optimizes the combination of multiple controllers. First, we summarize multiple controllers' combinations and schedule problems in an SDN and analyze its reliability. Then, we introduce the architecture of the schedule method and evaluate multi-controller reliability, the DSL method, and its optimized solution. By continually and statistically learning the information about controller reliability, this method treats it as a metric to schedule controllers. Finally, we compare and test the method using a given testing scenario based on an SDN network simulator. The experiment results show that the DSL method can significantly improve the total reliability of an SDN compared with a random schedule, and the proposed optimization algorithm has higher efficiency than an exhaustive search.

• Journal of Information Processing Systems
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• v.14 no.5
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• pp.1286-1292
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• 2018

To support and protect firefighters in the scene of disaster, this research suggests an Internet of Things (IoT) system architecture that can be configurable and applicable to firefighting and rescue in various disaster situations. The proposed approach provides increased adaptability and reusability of systems compared to existing approaches. To validate the feasibility of the approach, a system of systems based on the architecture was developed and successfully tested for a specific firefighting and rescue scenario in a given test environment.

• Journal of Auto-vehicle Safety Association
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• v.9 no.2
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• pp.26-32
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• 2017

This paper presents the lateral stability criteria for integrated chassis control. To determine the intervention timing of chassis control system, the lateral stability criteria is needed. The proposed lateral stability criteria is based on velocity-yawrate gain domain to determine whether vehicle is stable. If the yawrate gain violates the proposed criteria, the stability of the vehicle is considered as unstable. Characteristic velocity and critical velocity are employed to distinguish lateral stability criteria. The inside of the two boundaries is stable and the outside is unstable. If yawrate gain of vehicle violates the lateral stability criteria, the chassis control begin to intervene. To validate the lateral stability criteria, both computer simulations and vehicle test are conducted with respect to circular turn scenario. The proposed lateral stability criteria makes it possible to reduce intervention of chassis control system.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.1551-1554
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• 2012

차량전장용 운영체제는 안전중요(safety-critical) 소프트웨어로써 엄밀한 검증과 테스트를 필요로 한다. 엄밀한 검증은 시스템의 모든 사용 가능한 시나리오의 도출을 필요로 하며, 이것을 수작업으로 생성하는 데에는 비용과 효율성에 문제가 있다. 본 연구에서는 차량전장용 운영체제의 국제표준인 OSEK/VDX 에 명시된 제약사항을 고려한 테스트 시나리오 자동 생성기와 이를 보조하는 OSEK/VDX 시뮬레이터를 개발하여 테스트 효율의 향상과 자동화를 도모하였다. 개발된 도구는 OSEK/VDX 기반 개방형 운영체제인 Trampoline 에 적용하여 효과를 입증하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.1418-1420
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• 2012

클라우드 서비스는 네트워크 환경을 통해 사용자가 원하는 서비스를 장소에 구애받지 않고 수행될 수 있도록 지원하는 소프트웨어 응용의 일종이다. 이와 같은 클라우드 서비스의 개발과정에 서비스가 정확하게 실행된다는 것을 확인하는 것은 매우 중요하다. 그러나 신규 서비스 또는 새로운 패러다임의 클라우드 서비스를 개발하는 과정에서는 사용자 단말에서 서버까지 사용자가 원하는 서비스가 정확히 실행되는 가를 확인하는 것은 어려운 일이다. 왜냐하면 서비스 실행을 위해 다양한 경로에 존재할 수 있는 소프트웨어 컴포넌트가 올바르게 동작할 수 있는 가를 확인할 수 있어야 하기 때문이다. 본 연구에서는 이와 같이 클라우드 서비스의 개발과정에서 서비스 실행을 위한 경로 상에 존재하는 컴포넌트를 고려하는 시나리오 기반의 테스트 케이스 생성 기법을 제안한다.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.39.3-40
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• 2018

The presence of double red clump (RC) in the Milky Way bulge is widely accepted as evidence for a giant X-shaped structure originated from the bar instability. We suggested, however, a drastically different interpretation based on the multiple stellar populations phenomenon as is observed in globular clusters. Our discovery of a significant difference in CN-band between two RCs strengthens our scenario. On the other hand, recent Gaia survey provides trigonometric parallax distances for more than one billion stars in our Galaxy. These distance measurements would provide the important test as to the origin of the double RC in the Milky Way bulge. In this talk, we will present our preliminary results from Gaia DR2.

• Journal of Korea Multimedia Society
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• v.22 no.12
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• pp.1447-1456
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• 2019

As artificial intelligence technology is actively used in image processing, it is possible to generate high-quality fake images based on deep learning. Fake images generated using GAN(Generative Adversarial Network), one of unsupervised learning algorithms, have reached levels that are hard to discriminate from the naked eye. Detecting these fake images is required as they can be abused for crimes such as illegal content production, identity fraud and defamation. In this paper, we develop a deep-learning model based on CNN(Convolutional Neural Network) for the detection of StyleGAN fake images. StyleGAN is one of GAN algorithms and has an excellent performance in generating face images. We experiment with 48 number of experimental scenarios developed by combining parameters of the proposed model. We train and test each scenario with 300,000 number of real and fake face images in order to present a model parameter that improves performance in the detection of fake faces.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.41-44
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• 2007

In this paper, we introduce a system in which car navigation scenario is plugged multimodal interface based on multimodal middleware. In map-based system, the combination of speech and pen input/output modalities can offer users better expressive power. To be able to achieve multimodal task in car environments, we have chosen SCXML(State Chart XML), a multimodal authoring language of W3C standard, to control modality components as XHTML, VoiceXML and GPS. In Network Manager, GPS signals from navigation software are converted to EMMA meta language, sent to MultiModal Interaction Runtime Framework(MMI). Not only does MMI handles GPS signals and a user's multimodal I/Os but also it combines them with information of device, user preference and reasoned RDF to give the user intelligent or personalized services. The self-simulation test has shown that middleware accomplish a navigational multimodal task over multiple users in car environments.

• Journal of Auto-vehicle Safety Association
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• v.9 no.4
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• pp.7-13
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• 2017

As automotive industry develops, the demand for increasing traffic safety is growing. Lots of researches about vehicle convenience and safety technology have been implemented. Now, the autonomous driving test is being conducted all over the world, and the autonomous driving regulations are also being developed. Autonomous vehicles are being commercialized, but autonomous vehicle safety has not been guaranteed yet. This paper presents scenarios that assess the safety of autonomous vehicles by identifying the minimum requirements to ensure safety for a variety of situations on highway. In assessing driving safety, seven scenarios were totally selected. Seven scenarios were related to lane keeping and lane change performance in certain situations. These scenarios were verified by analyzing the driving data acquired through actual vehicle driving. Data analysis was implemented via computer simulation. These scenarios are developed based on existing ADAS evaluation and simulation of autonomous vehicle algorithm. Also Safety evaluation factors are developed based on ISO requirements, other papers and the current traffic regulations.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.117-122
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• 2020

In this paper, we study the electromagnetic interference in adjacent antenna aperture of multi-function radar for Integrated MAST of naval ship, which is operating plural radars, with test result of two different X-band antennas. Two antennas is placed in the test fixture copying the part of Integrated MAST for the experiment. The test figure is modeled to see the electromagnetic interference when antenna beam is steered by using electromagnetic analysis tool. Also, 6 test scenarios is determined to verify experimentally and each test scenario is run in an anechoic chamber. At the test antenna #1 radiates a pulse signal and the signal from the antenna #2 is stored and analyzed in the optic data format through a receiving device. Based on the result, the effect of electromagnetic interference is suggested when multi-function radars in the Integrated MAST are operating in adjacent distance.