• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.671-674
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• 2012

Recently, depending on the development of smart devices, a variable services have been offered to meet user's convenience. Due to these advance, the needs of users are extremely being diversified and more specific. In that situation, the needs for the N-Screen system has been varied and gradually evolved. An existing N-Screen system that use the way of video streaming upload its multimedia contents to their own cloud server so that might take a long play-reaction time and the number of user is limited by the server's performance. Because of the web based protocol adopted by existing N-Screen system, there are many different problems like high delay, overhead and something caused by simplex data communications. Therefore, to solve the problems above, this study proposes an application based on HTML5. This application supports Video tag and Progressive download via HTML5 so that improves the play-reaction time for multimedia contents. This system can also get rid of the chronic problems such as an access limitation for lots of users as per video streaming encoding. Also, through web sockets, this study proposes a system that has lower delay than the existing system and communicates in full duplex to be able to link dynamically.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1243-1244
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• 2022

In recent years, the growing interest in off-site construction has led to factories scaling up their manufacturing and production processes in the construction sector. Consequently, continuous large-scale site monitoring in low-variability environments, such as prefabricated components production plants (precast concrete production), has gained increasing importance. Although many studies on computer vision-based site monitoring have been conducted, challenges for deploying this technology for large-scale field applications still remain. One of the issues is collecting and transmitting vast amounts of video data. Continuous site monitoring systems are based on real-time video data collection and analysis, which requires excessive computational resources and network traffic. In addition, it is difficult to integrate various object information with different sizes and scales into a single scene. Various sizes and types of objects (e.g., workers, heavy equipment, and materials) exist in a plant production environment, and these objects should be detected simultaneously for effective site monitoring. However, with the existing object detection algorithms, it is difficult to simultaneously detect objects with significant differences in size because collecting and training massive amounts of object image data with various scales is necessary. This study thus developed a large-scale site monitoring system using edge computing and a small-object detection system to solve these problems. Edge computing is a distributed information technology architecture wherein the image or video data is processed near the originating source, not on a centralized server or cloud. By inferring information from the AI computing module equipped with CCTVs and communicating only the processed information with the server, it is possible to reduce excessive network traffic. Small-object detection is an innovative method to detect different-sized objects by cropping the raw image and setting the appropriate number of rows and columns for image splitting based on the target object size. This enables the detection of small objects from cropped and magnified images. The detected small objects can then be expressed in the original image. In the inference process, this study used the YOLO-v5 algorithm, known for its fast processing speed and widely used for real-time object detection. This method could effectively detect large and even small objects that were difficult to detect with the existing object detection algorithms. When the large-scale site monitoring system was tested, it performed well in detecting small objects, such as workers in a large-scale view of construction sites, which were inaccurately detected by the existing algorithms. Our next goal is to incorporate various safety monitoring and risk analysis algorithms into this system, such as collision risk estimation, based on the time-to-collision concept, enabling the optimization of safety routes by accumulating workers' paths and inferring the risky areas based on workers' trajectory patterns. Through such developments, this continuous large-scale site monitoring system can guide a construction plant's safety management system more effectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.83-94
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• 2016

Recent cloud, big data, there is a problem for the architectural security vulnerability to the server platforms of various fields such as artificial intelligence occurs consistently, but using the virtualization technology. In addition, most secure virtualization technology is known to be dependent on the type is limited and the platform provider. This paper presents a method for mutual authentication for secure data between multiple instances of a shared virtualized environment. The proposed method was designing a security architecture in consideration of the mutual authentication between multiple independent instances, and enhance the safety of a security protocol for sharing data by applying a key chain techniques. Performance analysis results and the existing security architecture demonstrated that protect each virtualized instances of the session and the other way, a compliance effectiveness for each instance of the mutual authentication process.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.93-99
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• 2017

The elevator system combines various convergence technologies with the development of ICT technology. Emergency call devices which are safety related devices is applied as an obligation of the elevator and those scope also varies. In this paper, we propose an integrated model that overcomes the limitations of existing voice emergency call devices and efficiently manages and manages video call based service structures in VoIP based on wired and wireless environments. This method effectively manages and operates various lift data and video records in the elevator between the manager, the server and the user. And also It is possible to secure the quality of video call in VoIP and cloud service environment and increase the reliability of safety management and enhance various service environment by creating an integrated structure utilizing various data and additional services in the elevator.

• Wind and Structures
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• v.20 no.6
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• pp.739-749
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• 2015

Field measurement of wind characteristics is of great significance for the wind engineering community. High-frequency anemometers such as ultrasonic anemometers are widely used to obtain the high-frequency fluctuating wind speed time history. However, conventional instrumentation systems may suffer from low efficiency, non-real time transmission and higher maintenance cost, and thus are not very appropriate in the field measurement of strong winds in remote areas such as mountain valleys. In order to improve the field measurement performance in those remote areas, a wireless high-frequency anemometer instrumentation system for field measurement has been developed. In this paper, the architecture of the proposed instrumentation system, and measured data transmission and treatment will be presented firstly. Then a comparison among existing instrumentation systems and the proposed one is made. It shows that the newly-developed system has considerable advantages. Furthermore, the application of this system to the bridge site located in the mountain valley is discussed. Finally, typical samples of measured data from this area are presented. It can be expected that the proposed system has a great application potential in the wind field measurement for remote areas such as the mountainous or island or coastal area, and hazardous structures such as ultra-voltage transmission tower, due to its real-time transmission, low cost and no manual collection of data and convenience.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.2
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• pp.11-19
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• 2015

Since CMOS device scaling has stalled, three-dimensional (3-D) integration allows extending Moore's law to ever high density, higher functionality, higher performance, and more diversed materials and devices to be integrated with lower cost. 3-D integration has many benefits such as increased multi-functionality, increased performance, increased data bandwidth, reduced power, small form factor, reduced packaging volume, because it vertically stacks multiple materials, technologies, and functional components such as processor, memory, sensors, logic, analog, and power ICs into one stacked chip. Anticipated applications start with memory, handheld devices, and high-performance computers and especially extend to multifunctional convengence systems such as cloud networking for internet of things, exascale computing for big data server, electrical vehicle system for future automotive, radioactivity safety system, energy harvesting system and, wireless implantable medical system by flexible heterogeneous integrations involving CMOS, MEMS, sensors and photonic circuits. However, heterogeneous integration of different functional devices has many technical challenges owing to various types of size, thickness, and substrate of different functional devices, because they were fabricated by different technologies. This paper describes new 3-D heterogeneous integration technologies of chip self-assembling stacking and 3-D heterogeneous opto-electronics integration, backside TSV fabrication developed by Tohoku University for multifunctional convergence systems. The paper introduce a high speed sensing, highly parallel processing image sensor system comprising a 3-D stacked image sensor with extremely fast signal sensing and processing speed and a 3-D stacked microprocessor with a self-test and self-repair function for autonomous driving assist fabricated by 3-D heterogeneous integration technologies.

• Journal of Korea Game Society
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• v.20 no.1
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• pp.121-132
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• 2020

This paper is about development of AR board game, "ZOOCUS", combined with board game and AR application for students with intellectual disabilities to improve their sociability, concentration, and working memory. This game, conducted with the support of the Netmarble Foundation in 2019, allows user to select different game level for individual intellectual level. Through the cloud server with network, student's experience can be shared with each other, and play data can be accumulated for objective evaluation of student's capabilities.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.5
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• pp.803-813
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• 2013

As the developments of smart devices and social network services, the amount of data has been exploding. The world is facing Big data era. For these reasons, the Big data processing technology which is a new technology that can handle such data has attracted much attention. One of the most representative technologies is Hadoop. Hadoop Distributed File System(HDFS) designed to run on commercial Linux server is an open source framework and can store many terabytes of data. The initial version of Hadoop did not consider security because it only focused on efficient Big data processing. As the number of users rapidly increases, a lot of sensitive data including personal information were stored on HDFS. So Hadoop announced a new version that introduces Kerberos and token system in 2009. However, this system is vulnerable to the replay attack, impersonation attack and other attacks. In this paper, we analyze these vulnerabilities of HDFS security and propose a new protocol which complements these vulnerabilities and maintains the performance of Hadoop.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.2
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• pp.315-327
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• 2017

Security threats such as unauthorized access and data tampering can occur during the virtual machine migration process. In particular, since virtual machine migration requires users to transfer important data and infrastructure information, it is relatively risky to other cloud services in case of security threats. For this reason, there is a need for dynamic authentication for virtual machine migration. Therefore, this paper proposes an OTP-based dynamic authentication framework to improve the vulnerabilities of the existing authentication mechanism for virtual machine migration. It consists of a virtual machine migration request module and an operation module. The request module includes an OTP-based user authentication process and a migration request process to a data center when a user requests a migration. The operation module includes a secure key exchange process between the data centers using SPEKE and a TOTP-based mutual authentication process between the data center and the physical server.

• Smart Media Journal
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• v.5 no.4
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• pp.18-25
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• 2016

Virtualized hardware resources provides efficiency in use and easy of management. Based on the benefits, virtualization techniques are used to build large server clusters and cloud systems. The performance of a virtualized system is significantly affected by the virtual machine scheduler. However, the existing virtual machine scheduler have a problem in that the I/O response is reduced in accordance with the scheduling delay becomes longer. In this paper, we introduce the Loan/Redemption mechanism of a virtual machine scheduler in order to improve the responsiveness to I/O events. The proposed scheme gives additional credits for to virtual machines and classifies the task characteristics of each virtual machine by analyzing the credit consumption pattern. When an I/O event arrives, the scheduling priority of a virtual machine is temporally increased based on the analysis. The evaluation based on the implementation shows that the proposed scheme improves the I/O response 60% and bandwidth of virtual machines 62% compared to those of the existing virtual machine scheduler.