• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.2
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• pp.105-111
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• 2006

Cryptographic application and coding theory require operations in finite field $GF(2^m)$. In such a field, the area and time complexity of implementation estimate by memory and time delay. Therefore, the effort for constructing an efficient multiplier in finite field have been proceeded. Massey-Omura proposed a multiplier that uses normal bases to represent elements $CH(2^m)$ [11] and Agnew at al. suggested a sequential multiplier that is a modification of Massey-Omura's structure for reducing the path delay. Recently, Rayhani-Masoleh and Hasan and S.Kwon at al. suggested a area efficient multipliers for modifying Agnew's structure respectively[2,3]. In [2] Rayhani-Masoleh and Hasan proposed a modified multiplier that has slightly increased a critical path delay from Agnew at al's structure. But, In [3] S.Kwon at al. proposed a modified multiplier that has no loss of a time efficiency from Agnew's structure. In this paper we will propose a multiplier by modifying Rayhani-Masoleh and Hassan's structure and the area-time complexity of the proposed multiplier is exactly same as that of S.Kwon at al's structure for type-II optimal normal basis.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.2
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• pp.177-184
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• 2008

In this study, in order to reduce appeals regarding vibration and noise from blasts, the optimum delay-time of the electronic detonator, which can minimize blast vibration, is found through blast-waveform composition and blasting simulation, and we have developed the full-face Sequential Blasting Method based on the studies of damping properties of full-face section blasting. The optimum delay-time of the electronic detonator and Full-face Sequential Blasting Method using electronic detonator was applied to the Gyeongbu high-speed railway construction site to test the feasibility of this method.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.10
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• pp.1131-1138
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• 2015

As the size of the internet market grows rapidly, the number of IPv4 addresses available is being exhausted, while transition to IPv6 is being delayed. As the best alternative solution, Network Address Translation(NAT) scheme is being used. It connects the public internet network with the private internet network in order to reduce the waste of IPv4 addresses space. The purpose of this paper is to study the effective example of network based on common virtual network using Packet Tracer with topology designed rather than usual theoretical approach in Dynamic NAT and PAT, which allows more efficient use of address space.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.5
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• pp.167-174
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• 2002

This paper analyzes the characteristics of three multipliers and squarers in finite fields GF(2/sup m/) from the point of view of processing time and area complexity. First, we analyze structures of three multipliers and squarers: 1) Systolic array structure, 2), LFSR structure, and 3) CA structure. To make performance analysis, each multiplier and squarer was modeled in VHDL and was synthesized for FPGA implementation. The simulation results show that CA structure is the best from the point view of processing time, and LFSR structure is the best from the point of view of area complexity.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.226-235
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• 1998

This study proposes the analysis and evaluation of method of time series of ultrasonic signal using the chaotic feature extraction for ultrasonic pattern recognition. The features are extracted from time series data for analysis of weld defects quantitatively. For this purpose, analysis objectives in this study are fractal dimension, Lyapunov exponent, and strange attractor on hyperspace. The Lyapunov exponent is a measure of rate in which phase space diverges nearby trajectories. Chaotic trajectories have at least one positive Lyapunov exponent, and the fractal dimension appears as a metric space such as the phase space trajectory of a dynamical system. In experiment, fractal(correlation) dimensions and Lyapunov exponents show the mean value of 4.663, and 0.093 relatively in case of learning, while the mean value of 4.926, and 0.090 in case of testing in slag inclusion(weld defects) are shown. Therefore, the proposed chaotic feature extraction can be enhancement of precision rate for ultrasonic pattern recognition in defecting signals of weld zone, such as slag inclusion.

• Journal of Internet Computing and Services
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• v.10 no.1
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• pp.33-41
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• 2009

Signals transmitted from access point (AP) or stations in different wireless LANs (WLAN) interfere each other when the WLANs are closely installed. When they are configured to use the same channel, signals from an WLAN get collided with signals from other WLANs so that the delay increases to user stations and the throughput decreases. In this paper, we propose a method in which an AP in a basic service set (BSS) detects other BSSs using the same channel and switches to a different channel not being occupied by any other BSS. We can avoid using the same channel with other BSS in spacially overlapped BSS environment. The proposed scheme is simulated and its characteristics are described with the analysis of the result. The results measured in terms of throughput show that the problems in overlapped wireless LANs can be resolved with the proposed method.

• Journal of the Korean Society for Railway
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• v.2 no.2
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• pp.21-30
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• 1999

This study proposes the analysis and evaluation method of time series ultrasonic signal using the phase space-frequency domain. Features extracted from time series signal analyze quantitatively characteristics of weld defects. For this purpose, analysis objectives in this study are features of time domain and frequency domain. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics resulting from distance shifts such as parts of head and flange even though the types of defects are identified. These differences in characteristics of weld defects enables the evaluation of unique characteristics of defects in the weld zone. In quantitative fractal feature extraction, feature values of 3.848 in the case of part of head(crack) and 4.102 in the case of part of web(side hole) and 3.711 in the case of part of flange(crack) were proposed on the basis of fractal dimension. Proposed phase space-frequency domain method in this study can integrity evaluation for defect signals of rail weld zone such as side hole and crack.

• Journal of Korean Association for Spatial Structures
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• v.17 no.4
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• pp.115-122
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• 2017

In this study, performance based seismic design was performed on the shear wall structural system and the beam-column system as a variable general rebar and seismic rebar, and comparing the capacity of the two models of each system. From nonlinear analyses, the capacity of the shear wall structural system applying seismic rebar has shown a stable behavior after the maximum strength, but there is little difference. Furthermore, both models showed similar capacity between story drift and story shear force and capacity of members. These results are attributed to the fact that the seismic rebar, which is highly ductile under the seismic load applied to the target structure, does not render sufficient capacity.

• 한국HCI학회:학술대회논문집
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• 2006.02b
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• pp.33-38
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• 2006

뉴미디어의 특성을 지니며 더욱 다양한 가능성과 관계를 열어나가게 된 오늘날의 현대 건축은 근대 이전의 구축적 양식 중심의 형식으로부터의 탈피, 디자인 분야의 심미적 발달, 자연 친화적인 관점으로의 발달, 그리고 무엇보다 인간 중심의 건축 발달 등으로 인해 구조, 실체와의 관련성 이외에 표면(surface)으로의 관심이 집중되면서 감상적인 공간 구조를 낳고 있다. 이는 표면이 공간적인 효과를 내는 표면을 통해 새로운 소통의 길이 열리게 되고 건축물 그 자체의 자율성을 표현하는 동시에 주변 컨텍스트에 동참하게 되므로 경계 영역으로서의 의미를 전달하는 인터페이스로 발전해 가고 있음을 시사한다. 또한 최근에는 더욱 적극적인 미디어 재료의 사용으로 건축의 표면이라기보다는 오히려 독립된 스크린으로써의 모습을 보여주고 있고, 그에 더해 다양한 미디어 아트 작업의 차용으로 표면의 스크린화는 더욱 진화하며 이전과는 또 다른 효과와 의미를 전달하고 있는데, 이는 공간 사용자의 능동적인 수용 형태를 인지하고 건축을 완성하는데 있어서 중요한 주체가 됨을 시사한다. 본 논문에서는 이러한 건축 표면이 가진 인터페이스로서의 특성과 최근의 적극적인 미디어 재료 사용 및 미디어 아트 차용을 통한 다양하고 새로운 소통의 시도를 분석해 봄으로써 건축 표면이 가지는 더욱 넓은 범위에서의 가능성과 잠재력을 건축 그 자체가 가지는 특성 안에서 뿐만 아니라 수용자와의 상호관계 안에서 또한 연구해 보고자 하였다.

• Korean Institute of Interior Design Journal
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• no.41
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• pp.96-103
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• 2003

The historical separation between organization studies and architecture area created a design environment in which wort processes are evaluated separately from setting where they occur. The impact of separation has been parallel yet disconnected development in th two disciplines in which the advance in one arena have not precipitated advances in the other. This is the unfortunate loss as each discipline has the potential to contribute directly to the other. With the emergence of new economy the opportunity to realign the tow disciplines is once again presented as new ways of working have enhanced this opportunity. It is important to revisit the historical development of the tow disciplines and to discuss how the misalignment of their respective concerns contributed to the establishment of our current situation. What happened to create an environment in which organizations assume that one of their largest capital expenditures the cost of providing work spaces for employees is unrelated to their work process\ulcorner what recent developments offer opportunities to rectify this dilemma\ulcorner In this study it is presented a historical review of organization studies and architecture. Through examination of these areas across time it becomes quite apparent that it is now appropriate to pose new questions about organization and their architecture. The comparison of two parallel developments explains how the current design environment is separated from organization studies and offers compelling evidence for why it is important to revisit this separation in light of contemporary theories on collaborative work, organizational learning and communities of practice.