• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1434-1439
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• 2004

CFRP composite materials have wide application in structure materials of airplane, ships, and aero space vehicles because of their high strength and stiffness. This paper is to study the effects of curvature and orientation angle on the penetration characteristics of CFRP laminate shell. They are staked with 8 Ply specimens [0$_2$/90$_2$]$_{s}$, [0/90$_2$/0]$_{s}$ and the stacked of outer plates degree with 12 Ply specimens [0$_3$/90$_3$]$_{s}$, [0$_2$/90$_2$/0]$_{s}$ and [90$_3$/0$_3$], [90$_2$/0$_2$/90]S. They are manufactured to varied curvature radius (R=100,150,200mm and $\infty$). They are cured by heating to the appropriate harding temperature(13$0^{\circ}C$) by mean of a heater at the vaccum bag of the autoclave. Test specimens were prepared with dimensions 100mm$\times$140mm. When the specimen is subjected to transverse impact by a steel ball, the velocity of the steel ball was measured both before and after impact by determining the time for it to pass two ballistic-screen sensor located a known distance apart. In general, kinetic energy after impact-kinetic energy before impact rised in all specimens. This study observed a fracture mode inside the specimen after a penetration test using a digital camera and it examined a fracture mode and a penetration mode to stack of outer orientation angle and curvature.rvature.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.211-216
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• 2012

Proton Exchange Membrane Fuel Cells (PEMFC) are the most appropriate for energy source of small robot applications. PEMFC has superior in power density and thermodynamic efficiency as compared with the Direct Methaol Fuel Cell (DMFC). Furthermore, PEMFC has lighter weight and smaller size than DMFC which are very important factors as small robot power system. The most significant factor of mobile robots is weight which relates closely with energy consumption and robot operation. This research tried to find optimum specifications in terms of type, number of cell, active area, cooling method, weight, and size. In order to find optimum 500W PEMFC, six options are designed in this paper and studied to reduce total stack weight by applying new materials and design innovations. However, still remaining problems are thermal management, robot space for energy sources, and so on. For a thermal management, design options need to analysis of Computational Fluid Dynamics (CFD) for determining which option has the improved performance and durability.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.119-126
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• 2017

Developing the TCP/IP standard IBA which is higher organization of IETF decided to attach the TCP/IP protocol stack to small things, such as sensor. This means small object is also considered as on of the communication node, it has symbolic meaning that expand smart object has all five layer. Under this background, IoT/WoT configure the intelligent network between objects based on the internet to communication was introduced. Things has own IP address on IoT environment and are smart object that a lot of people communicate over the internet on Application Layer. In other words, IoT is that smart object are commercialized space. According to the interest of IoT, IETF establish CoAP for use as IoT protocol. CoAP is expected that standard protocols created by things is connected to the Internet protocol that can be used within a constrained environment. Accordingly, in this paper, we proposed Middleware API that can manage and collect the data of objects that connected CoAP network.

• Journal of the Korea Society of Computer and Information
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• v.15 no.12
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• pp.93-100
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• 2010

In this paper, we propose a technique which makes it faster to delete prefixes in an IP address lookup architecture based on parallel TCAMs. In previous deletion schemes, more than one memory movement is needed for the prefix ordering and keeping the available memory space consecutive. For deletion, our scheme stores the address of the deleted prefix in a stack implemented by SRAM instead of actual movement in TCAM. Since SRAM has very short latency compared to TCAM, the proposed scheme can accomplish fast updating. From the experiment with the real forwarding table and update trace, we evaluate the performance of our scheme in terms of the memory access time for the prefix insertion and deletion. The experiment result also shows good performance with considerably small size of stack.

• Journal of Advanced Navigation Technology
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• v.14 no.6
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• pp.975-983
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• 2010

In this paper, we introduce extended problems of Tower of Hanoi (ToH) and propose a novel visualization method to express a state space of ToH. As for the extended problems, we introduce multi-peg ToH, multi-stack ToH, and regular state ToH. The novel visualization method in this paper is a natural extension of Hanoi graph visualization. In the proposed method, we assign one Cartesian coordinate point per each disk to provide an unified visualization that the marks on a link and the changes of a state should correspond with a peg position of a disk. Compared with Hanoi graph, the generated graph by the proposed method is isomorphic if we remove links of forbidden move, which indicates that our method is a generalization of Hanoi graph and thus is more expressive. To help the understanding of the readers, we show the generated graphs by our method when the number of disks is 2 and 3.

• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.288-296
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• 2021

Automated face recognition in a runtime environment is gaining more and more important in the fields of surveillance and urban security. This is a difficult task keeping in mind the constantly volatile image landscape with varying features and attributes. For a system to be beneficial in industrial settings, it is pertinent that its efficiency isn't compromised when running on roads, intersections, and busy streets. However, recognition in such uncontrolled circumstances is a major problem in real-life applications. In this paper, the main problem of face recognition in which full face is not visible (Occlusion). This is a common occurrence as any person can change his features by wearing a scarf, sunglass or by merely growing a mustache or beard. Such types of discrepancies in facial appearance are frequently stumbled upon in an uncontrolled circumstance and possibly will be a reason to the security systems which are based upon face recognition. These types of variations are very common in a real-life environment. It has been analyzed that it has been studied less in literature but now researchers have a major focus on this type of variation. Existing state-of-the-art techniques suffer from several limitations. Most significant amongst them are low level of usability and poor response time in case of any calamity. In this paper, an improved face recognition system is developed to solve the problem of occlusion known as FRS-OCC. To build the FRS-OCC system, the color and texture features are used and then an incremental learning algorithm (Learn++) to select more informative features. Afterward, the trained stack-based autoencoder (SAE) deep learning algorithm is used to recognize a human face. Overall, the FRS-OCC system is used to introduce such algorithms which enhance the response time to guarantee a benchmark quality of service in any situation. To test and evaluate the performance of the proposed FRS-OCC system, the AR face dataset is utilized. On average, the FRS-OCC system is outperformed and achieved SE of 98.82%, SP of 98.49%, AC of 98.76% and AUC of 0.9995 compared to other state-of-the-art methods. The obtained results indicate that the FRS-OCC system can be used in any surveillance application.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.435-437
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• 2004

In this paper, we aim to design and implement supporting IPv6 Bluetooth Access point(AP) in Linux. Bluetooth is a cable replacement technology designed for short range ad-hoc connections, which most likely change the way we handle and access information in the near future. In Personal Area Network(PAN) mobile devices need many IP address space, then we need next generation Internet Protocol(IPv6). We designed Bluetooth Access Point with Bluetooth stack and MAC bridge function in Linux. The implementation tested on Linux system based on Bluetooth Access Point with other Bluetooth devices.

• Journal of information and communication convergence engineering
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• v.12 no.1
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• pp.46-52
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• 2014

This article presents key research needs in three-dimensional integrated circuit (3D IC) architectural floorplanning. Architectural floorplaning is done at a very early stage of 3D IC design process, where the goal is to quickly evaluate architectural designs described in register-transfer level (RTL) in terms of power, performance, and reliability. This evaluation is then fed back to architects for further improvement and/or modifications needed to meet the target constraints. We discuss the details of the following research needs in this article: block-level modeling, through-silicon-via (TSV) insertion and management, and chip/package co-evaluation. The goal of block-level modeling is to obtain physical, power, performance, and reliability information of architectural blocks. We then assemble the blocks into multiple tiers while connecting them using TSVs that are placed in between hard IPs and inside soft IPs. Once a full-stack 3D floorplanning is obtained, we evaluate it so that the feedback is provided back to architects.

• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.3023-3032
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• 1997

This study examined individual differences in navigating in hyperspace learning environment where a minimum structure is provided. Using a hypercard stack called "Pearl Harbor", Field Dependent people used guidance more often than those in Field Indepedent; FI achieved scored higher at the end of the study; and FI people had some type of pattern showing from them audit trail when FD people did not show any trail of patterns. Also people with higher visual thinking scores achieved higher scores in hyperspace environment.

• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.4
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• pp.175-184
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• 2010

This paper designs a virtual USB drive for mobile devices which gives an illusion of a traditional USB flash memory drive and provides capacity-free storage space over IP network. The virtual USB drive operating with a S3C2410 hardware platform and embedded linux consists of USB device driver, an iSCSI-enabled network stack, and a seamless USB/iSCSI tunneling module. For performance enhancement, it additionally provides a kernel-level seamless USB/iSCSI tunneling module and data sharing with symbol references among kernel modules. Experiments reveal that the kernel-level implementation can improve the I/O performance up to 8 percentage, as compared with the user-level implementation.