• Convergence Security Journal
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• v.5 no.3
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• pp.23-32
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• 2005

This paper presents a 128-bit Reversible Cellular Automata (RCA) based lightweight block cipher for Ubiquitous computing security. To satisfy resource-constraints for Ubiquitous computing, it is designed as block architecture based on Cellular Automata with high pseudo-randomness. Our implementation requires 704 clock cycles and consumes 2,874 gates for encryption of a 128-bit data block. In conclusion, the processing time outperformed that of AES and NTRU by 31%, and the number of gate was saved by 20%. We evaluate robustness of our implementation against both Differential Cryptanalysis and Strict Avalanche Criterion.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.339-344
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• 2007

이동통신 단말기의 그래픽 유저 인터페이스 환경은 다양한 요인에 의하여 그 변화를 자극 받고 있다. 한정된 디스플레이 공간 안에서의 다 기능화로 인한 사용성의 문제, 정적이고 지시적인 상황에 익숙한 문자 중심의 세대에서 자율적이고 동적인 영상 중심의 세대로의 사용자 세대의 변화, 합리적 소비 보다는 감성적 만족을 중요하게 여기는 사용자 가치의 변화, 그래픽 디자인 트랜드의 변화, 서비스 컨텐츠의 변화, 기술의 발전 등 이동통신 단말기를 둘러싼 모든 측면에서 변화가 진행되고 있다. 여기에 이동통신 단말기 제조사, 서비스 업체, 컨텐츠 업체, 칩 제조사 등 이동통신 서비스와 관련된 다양한 사업 주체들의 복잡한 이해관계 속에서의 경쟁 또한 이러한 변화를 부추기는 요인의 하나로 볼 수 있다. 본 연구에서는 이러한 변화요인들을 적절히 수렴하여 제공할 수 있는 보다 효과적인 그래픽 유져 인터페이스 디자인 방법을 모색하고자 하였으며, 보다 효율적이고 적극적인 개선을 위해 현재 이동통신 단말기의 GUI 디자인의 주요 디자인 수단인 Bitmap 또는 Vector 그래픽 대신 보다 다양한 시각적 표현 방법을 내재하고 있는 3D 기반의 Motion 그래픽을 활용한 이동통신 단말기의 GUI 디자인 방법을 제안 하고자 한다. 하지만 아직 여러가지 제약 조건들로 인하여 이동통신 단말기 내에서 3D Motion 그래픽의 적용이 완전히 자유롭지 않은 것이 사실이다. 그러나 기술의 발전 속도로 볼 때 머지 않아 3D Motion GUI 제공을 위한 이동통신 단말기의 기술적 환경은 충분히 발전될 것이며, 이에 따라 본 연구와 같이 3D 그래픽이나 Motion 그래픽을 등을 활용한 이동통신 단말기의 사용자 인터페이스 연구의 선행은 매우 필요하다고 볼 수 있다.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.11
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• pp.601-610
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• 2002

Intra-task voltage scheduling (IntraVS), which adjusts the supply voltage within an individual task boundary, is an effective technique for developing low-power applications. In this paper, we propose a novel intra-task voltage scheduling algorithm for hard real-time applications based on average-case execution time. Unlike the conventional IntraVS algorithm where voltage scaling decisions are based on the worst-case execution cycles, tile proposed algorithm improves the energy efficiency by controlling the execution speed based on average-case execution cycles while meeting the real-time constraints. The experimental results using an MPEG-4 decoder program show that the proposed algorithm reduces the energy consumption by up to 34% over conventional IntraVS algorithm.

• Water for future
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• v.25 no.4
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• pp.61-73
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• 1992

There are needs to examine the consequences of a regulation in effect to control the migration of leachates from disposal sites. The main objective of this study is to illustrate the methodology to evaluate basic disposal designs for compliance with a certain regulation, The "100/100 rule" is selected for demonstration purpose which dictates that the time for the leachates to travel a horizontal distance of 100feet (30.5m) away from the property where the landfill or pond is located must exceed 100 years. The two primary methods for disposal of ash from coal-fired utility plants, landfill and pond, are studied, Numerical groundwater flow analysis resulted in pressure head distribution and flux information in the cross-section of the domain while path line analysis provided travel path and time of leachate migration to compliance zone.ance zone.

• Journal of the Korean GEO-environmental Society
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• v.9 no.5
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• pp.15-20
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• 2008

Compressibility of the marine clay was mainly studied velocity of consolidation and numerical analysis by this time but studies of reevaluated from the field measurement data was a little. For last three years, areal fills and extensive field instrumentations including settlement and pore water pressure were performed in the site of the Youngsan River estuary site, South Korea. From the settlement data, field consolidation curves for sub-layers were reconstructed. Effective surcharge loads during the staged loadings were calculated using the fill heights and the excess pore water pressures in the ground. In the numerical analysis (PLAXIS), prefabricated vertical drains were also simulated. Laboratory, field, and numerical analysis showed good agreements in compressibility. Due to different conditions and limitations of the clay was the same range of the oedometer tests.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.5
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• pp.60-70
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• 2007

As Republic of Korea community nears to old age society rapidly, various kinds problem about old mans is risen. Can speak that item connected with medical treatment is more serious in the importance aspect among them Therefore, many-sided effort is consisting to ready countermeasure in reply, but economical method is not presented clearly as being realistic yet. Also, medical treatment service that more users through diffusion of fast internet are little more better effort that serve consist. But, in the case of old age, by difficulty of the use, restriction condition happens. In this paper proposed system that is prevailing already and user-friendly can cope curtly in old mans' emergency situation more rapidly and conveniently using mobile phone of CDMA way relatively.

• The Transactions of the Korea Information Processing Society
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• v.6 no.12
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• pp.3703-3709
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• 1999

We propose a new approach to reconstruct the surface shape of an object from a shaded image. We use genetic algorithm instead of gradient descent algorithm which is apt to take to local minima and also proposes genetic representation and suitable genetic operators for manipulating 2-D image. And for more effective execution, we suggest hierarchical process to reconstruct minutely the surface of an object after coarse and global reconstruction. A modified Lambertian illumination model including the distance factor was herein adopted to get more reasonable result and an experiment was performed with synthesized and real images to demonstrate the devised method, of which results show the usefulness of our method.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.11
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• pp.771-781
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• 2022

Sequential convex programming based performance analysis of the designed UAV is performed. The nonlinear optimization problems generated by aerodynamics are approximated to socond order program by discretization and convexification. To improve the performance of the algorithm, the solution of the relaxed problem is used as the initial trajectory. Dive trajectory optimization problem is analyzed through iterative solution procedure of approximated problem. Finally, the maximum final velocity according to the performance of the actuator model was compared.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.212-215
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• 2009

옷감 시뮬레이션은 지금까지 게임, 애니메이션, 영화 등에 많이 사용되어왔고, 현재 증강현실(Augmented Reality) 환경에서의 교육자료, 쇼핑몰 뿐만 아니라 휴대용 게임기, 휴대폰 등 모바일 기기에서도 그 응용이 점점 증가하는 추세다. PC에 비해 그래픽스 하드웨어의 성능이 떨어지는 기기에서 3차원 시뮬레이션을 가능하게 하기 위해서는 모델의 움직임을 최대한 근사(Approximation)하면서 계산 속도를 보장하는 방법이 필요하다. 즉, 상호작용(Interaction)이 필요한 사용자 입장에서는 최소한의 정확성만 보장한다면 실시간 시뮬레이션이 더 큰 이슈가 된다. 따라서 이 논문에서는 증강현실 환경에서 실시간 시뮬레이션을 보장하는 옷감 시뮬레이션 방법을 제안한다. 안정성과 정확성이 보장되는 적분법(Integration)을 사용하였고, 옷감의 길이가 비사실적으로 늘어나지 않게 하기 위해 제약 조건(Constraints)을 주었다. 또한 각 지점에서의 곡률(Curvature)을 고려하여 충돌 검사를 함으로써 옷감 내부 충돌 검사로 요구되는 많은 계산량을 효율적으로 처리하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.2
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• pp.138-145
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• 2000

A identification algorithm that finds optimal fuzzy membership functions and rule base to fuzzy model isproposed and a fuzzy controller is designed to get more accurate position and velocity control of wheeled mobile robot. This procedure that is composed of three steps has its own unique process at each step. The elements of output term set are increased at first step and then the rule base is varied according to increase of the elements. The adjusted system is in competition with system which doesn't include any increased elements. The adjusted system will be removed if the system lost. Otherwise, the control system is replaced with the adjusted system. After finished regulation of output term set and rule base, searching for input membership functions is processed with constraints and fine tuning of output membership functions is done.