RESULTS OF THERMAL CREEP TEST ON HIGHLY IRRADIATED ZIRLO

Quecedo, M.,Lloret, M.,Conde, J.M.,Alejano, C.,Gago, J.A.,Fernandez, F.J. Korean Nuclear Society 2009 Nuclear Engineering and Technology Vol.41 No.2

This paper presents a thermal creep test under internal pressure and post-test characterization performed on high burnup (68 MWd/kgU) ZIRLO. This research has been done by the CSN, ENRESA, and ENUSA in order to investigate the behavior of advanced cladding materials in contemporary PWRs at higher burnup under dry cask storage conditions. Also, to investigate the hydride reorientation, the cool-down of the samples after the test has been done in a coordinated manner with the internal pressure. The creep results obtained are consistent with the expected behavior from reference CWSR material, Zr-4. During the test, the material retained significant ductility: one specimen leaked during the test at an engineering strain of the tube section of 17%; remarkably, the crack closed due to de-pressurization. Although significant hydride reorientation occurred during the cool-down under pressure, no specimen failed during the cool-down.

RESULTS OF THERMAL CREEP TEST ON HIGHLY IRRADIATED ZIRLO

M. QUECEDO,M. LLORET,J. M. CONDE,C. ALEJANO,J.A. GAGO,F.J. FERNÁNDEZ 한국원자력학회 2009 Nuclear Engineering and Technology Vol.41 No.2

This paper presents a thermal creep test under internal pressure and post-test characterization performed on high burnup (68 MWd/kgU) ZIRLO. This research has been done by the CSN, ENRESA, and ENUSA in order to investigate the behavior of advanced cladding materials in contemporary PWRs at higher burnup under dry cask storage conditions. Also, to investigate the hydride reorientation, the cool-down of the samples after the test has been done in a coordinated manner with the internal pressure. The creep results obtained are consistent with the expected behavior from reference CWSR material, Zr-4. During the test, the material retained significant ductility: one specimen leaked during the test at an engineering strain of the tube section of 17%; remarkably, the crack closed due to de-pressurization. Although significant hydride reorientation occurred during the cool-down under pressure, no specimen failed during the cool-down.

Efficient Conversion of Deep Features to Compact Binary Codes Using Fourier Decomposition for Multimedia Big Data

Ahmad, Jamil,Muhammad, Khan,Lloret, Jaime,Baik, Sung Wook IEEE 2018 IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS - Vol.14 No.7

<P>Exponential growth of multimedia data has been witnessed in recent years from various industries, such as e-commerce, health, transportation, and social networks, etc. Access to desired data in such gigantic datasets require sophisticated and efficient retrieval methods. In the last few years, neuronal activations generated by a pretrained convolutional neural network (CNN) have served as generic descriptors for various tasks including image classification, object detection and segmentation, and image retrieval. They perform incredibly well compared to hand-crafted features. However, these features are usually high dimensional, requiring a lot of memory and computations for indexing and retrieval. For very large datasets, utilization of these high dimensional features in raw form becomes infeasible. In this paper, a highly efficient method is proposed to transform high dimensional deep features into compact binary codes using bidirectional Fourier decomposition. This compact bit code saves memory and eases computations during retrieval. Further, these codes can also serve as hash codes, allowing very efficient access to images in large datasets using approximate nearest neighbor (ANN) search techniques. Our method does not require any training and achieves considerable retrieval accuracy with short length codes. It has been tested on features extracted from fully connected layers of a pretrained CNN. Experiments conducted with several large datasets reveal the effectiveness of our approach for a wide variety of datasets.</P>

적극적 교육

Petra de Llanos,Lloret, Gemma 한국외국어대학교 1993 한국외국어대학교 논문집 Vol.26 No.-

SIR performance evaluation of MB-OFDM UWB system with residual timing offset

Islam, S. M. R.,Ullah, S.,Lloret, J.,Ullah, N.,Kwak, K. S. IET 2015 Electronics letters Vol.51 No.5

<P>Signal-to-interference ratio (SIR) performance of a multiband orthogonal frequency division multiplexing ultra-wideband system with residual timing offset is investigated. To do so, an exact mathematical derivation of the SIR of this system is derived. It becomes obvious that, unlike a cyclic prefixing based system, a zero padding based system is sensitive to residual timing offset.</P>

Collaborative Creation with Soundcool for Socially Distanced Education

Jorge Sastre(호르헤 사스트레),Nuria Lloret(누리아 로렛),Stefano Scrani(스테파노 스크라니),Roger B. Dannenberg(로저 비 다넨베르그),Jesus Jara(헤수스 하라) 한국전자음악협회 2020 에밀레 Vol.18 No.-

사운드쿨<SUB>Soundcool</SUB>은 음악 교육을 위해 제작된 유연하면서 모듈식의 컴퓨터 음악 소프트웨어 시스템이다. 또한, 사운드쿨은 교사가 연구과제 기반의 학습을 지도하는 수업에서 협동과 발견 단계를 아우르는 교육적 접근방법도 가지고 있다. 협동을 실현하기 위해서, 사운드쿨은 처음부터 각 스마트폰이나 태블릿앱을 와이파이를 통해 사용하여 개별 모듈 단위로 제어할 수 있도록 설계되었다. 이러한 협동과정은 장거리에서도 네트워크 기반의 실행이 가능하다. 특히, 최근 사회적 거리두기의 요구로 인해 사운드쿨이 원격 교육에 활용되고 젊은 음악가들이 창의적인 방식으로 함께 공연할 수 있도록 더욱 많은 연구를 시도하였다. 저자들은 사운드쿨의 교육적 접근법과 아이들의 네트워크 공연 경험하기, 웹 기반의 사회적 네트워크 기반 협동 음악 창작 시스템에 대한 향후 계획에 대하여 논의한다. Soundcool is a flexible, modular computer music software system created for music education. Moreover, Soundcool is an educational approach that embraces collaboration and discovery in which the teacher serves as a mentor for project‐based learning. To enable collaboration, Soundcool was designed from the beginning to allow individual modules to be controlled over Wi‐Fi using smartphone and tablet apps. This collaborative feature has enabled network‐based performance over long distances. In particular, the recent demand for social distancing motivated further explorations to use Soundcool for distance education and to enable young musicians to perform together in a creative way. We describe the educational approach of Soundcool, experience with network performances with children, and future plans for a web‐based social‐network‐inspired collaborative music creation system.

Secure Surveillance Framework for IoT Systems Using Probabilistic Image Encryption

Muhammad, Khan,Hamza, Rafik,Ahmad, Jamil,Lloret, Jaime,Wang, Haoxiang,Baik, Sung Wook IEEE 2018 IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS - Vol.14 No.8

<P>This paper proposes a secure surveillance framework for Internet of things (IoT) systems by intelligent integration of video summarization and image encryption. First, an efficient video summarization method is used to extract the informative frames using the processing capabilities of visual sensors. When an event is detected from keyframes, an alert is sent to the concerned authority autonomously. As the final decision about an event mainly depends on the extracted keyframes, their modification during transmission by attackers can result in severe losses. To tackle this issue, we propose a fast probabilistic and lightweight algorithm for the encryption of keyframes prior to transmission, considering the memory and processing requirements of constrained devices that increase its suitability for IoT systems. Our experimental results verify the effectiveness of the proposed method in terms of robustness, execution time, and security compared to other image encryption algorithms. Furthermore, our framework can reduce the bandwidth, storage, transmission cost, and the time required for analysts to browse large volumes of surveillance data and make decisions about abnormal events, such as suspicious activity detection and fire detection in surveillance applications.</P>

OBPF: Opportunistic Beaconless Packet Forwarding Strategy for Vehicular Ad Hoc Networks

( Kashif Naseer Qureshi ),( Abdul Hanan Abdullah ),( Jaime Lloret ),( Ayman Altameem ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.5

In a vehicular ad hoc network, the communication links are unsteady due to the rapidly changing topology, high mobility and traffic density in the urban environment. Most of the existing geographical routing protocols rely on the continuous transmission of beacon messages to update the neighbors` presence, leading to network congestion. Source-based approaches have been proven to be inefficient in the inherently unstable network. To this end, we propose an opportunistic beaconless packet forwarding approach based on a modified handshake mechanism for the urban vehicular environment. The protocol acts differently between intersections and at the intersection to find the next forwarder node toward the destination. The modified handshake mechanism contains link quality, forward progress and directional greedy metrics to determine the best relay node in the network. After designing the protocol, we compared its performance with existing routing protocols. The simulation results show the superior performance of the proposed protocol in terms of packet delay and data delivery ratio in realistic wireless channel conditions.

IoTEC: IoT based Efficient Clustering Protocol for Wireless Sensor Network

Amjad Mehmood,S. Khan,Daqiang Zhang,Jaime Lloret,Syed Hassan Ahmed 한국산업정보학회 2014 한국산업정보학회 학술대회논문집 Vol.2014 No.1

Enhancing Security in Mobile IPv6

Hero Modares,Amirhossein Moravejosharieh,Rosli Bin Salleh,Jaime Lloret 한국전자통신연구원 2014 ETRI Journal Vol.36 No.1

In the Mobile IPv6 (MIPv6) protocol, a mobile node(MN) is a mobile device with a permanent home address(HoA) on its home link. The MN will acquire a care-ofaddress (CoA) when it roams into a foreign link. It thensends a binding update (BU) message to the home agent(HA) and the correspondent node (CN) to inform them ofits current CoA so that future data packets destined for itsHoA will be forwarded to the CoA. The BU message,however, is vulnerable to different types of security attacks,such as the man-in-the-middle attack, the sessionhijacking attack, and the denial-of-service attack. Thecurrent security protocols in MIPv6 are not able toeffectively protect the BU message against these attacks. The private-key-based BU (PKBU) protocol is proposed inthis research to overcome the shortcomings of someexisting MIPv6 protocols. PKBU incorporates a method toassert the address ownership of the MN, thus allowing theCN to validate that the MN is not a malicious node. Theresults obtained show that it addresses the securityrequirements while being able to check the addressownership of the MN. PKBU also incorporates a methodto verify the reachability of the MN.