• Journal of Internet of Things and Convergence
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• v.2 no.4
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• pp.27-34
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• 2016

In this paper, we designed and implemented a system to easily check and manage book inventory using web and Android mobile device. In the previous conventional method, the user visits the bookstore directly and then checks the inventory. However, in this case, the user accessibility is inconvenient, and it is troublesome to check or reconfirm the inventory. In order to solve these inconveniences, we provide book inventory management system for requesting book purchase and inquiring bulletin board by book field, and then providing real time inventory check with book application and purchase functions. In addition, through the push notification function, we can catch up with the purchase status of the ordered books on the web and Android mobile device in real time. Therefore, we designed and implemented a function that enables bookstore operators and users to easily and conveniently manage by providing statistical information on inventory data.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.101-104
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• 2008

The cost of repairing the deterioration of concrete structures due to corrosion of the reinforcement steel has been the prominent figure in the maintenacne of the reinforced-concrete infrastructures. As an alternative material to steel reinforcement, the use of Fiber Reinforced Polymer (FRP) bar in concrete is being actively studied for the high resistance of chemical environment and high strength to weight ratio properties of FRP. However, there remain various aspects of FRP properties that still need to be studied before the standard design criteria can be established. One of the imminent issues is the bond between FRP and concrete. In this study, the bond-behavior of FRP bars in concrete is investigated via the pullout test with three varying parameters: surface condition of FRP bars, concrete compression strength, and cyclic loading patterns. As a result of experiment, the bond strength of GFRP increased with the concrete compression strength increasing and decreased with applying cyclic load.

• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.1
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• pp.9-16
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• 2020

Recently, the capacity of SSD has been increasing rapidly due to the improvement of flash memory density. To take full advantage of these SSDs, first of all, FTL's prompt adaptation is necessary. The FTL is a translation layer existing in SSDs to overcome the drawback of the SSD that cannot be modified in place, and has garbage collection and caching functions in addition to the map table management function. In this study, we focus on caching function, compare and analyze the cache implementation methodologies, and propose improved methods. Typical cache implementations divide the cache into groups, manage and retrieve the caches in the group as a linked list. Thus, searches are made in the order of the linked list. In contrast, we propose a method of sequential searching using the search area group of a cache registered in the map table regardless of the linked list and cache group. Experimental results show that the proposed method has a 2.5 times improvement over the conventional method.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.1
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• pp.71-76
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• 2013

A computer worm is a standalone malware computer program that probes and exploits vulnerabilities of systems. It replicates and spreads itself to other computers via networks. In this paper, we study how to detect and prevent worms. First, we generated Codered II traffic on the emulated testbed called Deterlab. Then we identified dubious parts using Earlybird and wrote down Snort rules using Wireshark. Finally, by applying the Snort rules to the traffic, we could confirmed that worm detection was successfully done.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.8
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• pp.867-875
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• 2009

A wireless sensor network inherently comprises a plurality of sensor nodes widely deployed for sensing environmental information. To add new functions or to correct some faulty functions of an existing wireless sensor network, the firmware for each sensor node needs to be updated. Firmware update would be quite troublesome if it requires the gathering, reprogramming, and redeploy of all of already deployed sensor nodes. Over-the-air programming (OTA) facilitates the firmware update process, thereby allowing convenient maintenance of an already-deployed sensor network. This paper proposes and implements a remote firmware update mechanism for a TDMA-based wireless sensor network, in which the firmware for sensor nodes constituting the TDMA-based sensor network can be easily updated and the update process can be conveniently monitored from a remote site. We verify the validity of the proposed firmware update method via experiments and introduce three wireless sensor networks installed in outdoor sites in which the proposed firmware update mechanism has been exploited.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.01a
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• pp.73-76
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• 2015

최근 스마트 단말을 통한 유해 콘텐츠의 보급이 확산되면서 스마트 단말에서 유해 콘텐츠를 차단하기 위한 소프트웨어의 필요성이 증가하고 있다. 이에 본 논문에서는 안드로이드 기반 스마트 단말에서 실행 이벤트의 분석을 통하여 유해 콘텐츠를 탐지 할 수 있는 방법을 제안한다. 본 논문에서는 안드로이드기반 스마트 단말에서 스트리밍 서비스가 실행되는 구조 및 관련 실행 이벤트들의 연관성을 분석하였으며, 분석 결과를 토대로 스마트 단말에서 유해 콘텐츠의 실행 여부를 판단할 수 있는 소프트웨어를 개발하였다.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.3
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• pp.139-150
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• 2015

The major components of IoT(Internet of Things) environment are IoT devices rather than the conventional desktop computers. One of the intrinsic characteristics of IoT devices is diversity in view of data type and data access method. In addition, IoT devices usually deal with real-time data. In order to use such IoT data for internal business or cloud services, an IoT platform capable of easy domain management and consistent data access interface is required. This paper proposes a Linux FUSE-based virtual file system connecting IoT devices on POSIX file system view. It is possible to manage IoT domain with the native Linux utilities such as mkdir, mknod, ls and find in the file system. Also, the file system makes it possible to access or control IoT devices through POSIX interface such as open(), read(), write() or close() without any separate APIs or utilities. A test result shows that the management performance of the file system is lower than that of linux file system negligibly.

• Korean Journal of Head & Neck Oncology
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• v.27 no.1
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• pp.88-91
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• 2011

Our case presents unusual case of Bilateral second brachial cleft fistulas The brachiogenic anomalies usually arise from an imcomplete obliteration of branchial appartus are common congenital cervical anomalies. But Bilateral manifestation are very rare. We treated it with surgical excision and it has not occurred recurrence until now. So we report about its character and treatment of Bilateral second brachial cleft fistulas.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.4
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• pp.337-342
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• 2001

A natural disaster occupies a considerable part among various damages, and the damage of human lifes and property by heavy rain extends to hundreds, and billions in every you. In old times, flood was mainly occurred in big river or sudden slope, but these days, the damage of concentrated heavy rain is being extended to a city. Recently, very big floods occurred continuously, so real time submersion expectation system which can expect the inundation boundary according to the scale is needed so as to protect lifes and property. In this study, in and around Jungrang river, where the damage of flood is big, is chosen as a sample, and the submersion of that area is expected by analyzing the flux and overflowing using DEM, and connecting with Web GIS in real time.

• Transactions of Materials Processing
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• v.13 no.3
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• pp.285-289
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• 2004

Micro tensile test specimens of thin film single crystal silicon for the most useful structural materials in MEMS (Micro Electro Mechanical System) devices were fabricated using SOI (Silicon-on-Insulator) wafers and MEMS processes. Dimensions of micro tensile test specimens were thickness of $7\mu\textrm{m}$, width of 50~$350\mu\textrm{m}$, and length of 2mm. Top and bottom silicon were etched using by deep RIE (Reactive Ion Etching). Thin film aluminum markers on testing region of specimens with width of $5\mu\textrm{m}$, lengths of 30~$180\mu\textrm{m}$ and thickness of 200 nm for measuring tensile strain were fabricated by aluminum wet etching method. Fabricated side wall angles of aluminum marker were about $45^{\circ}~50^{\circ}$. He-Ne laser with wavelength of 633nm was used for checking fringed patterns.