• 대한전자공학회논문지TE
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• 제39권3호
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• pp.90-96
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• 2002

역할기반 접근통제(RBAC：Role-Based Access Control)는 사용자의 역할에 기반을 둔 접근통제 방법으로 다양한 컴퓨터, 네트워크 보안 분야에 있어서 유연성을 제공한다. 그러나 역할기반 접근통제는 역할이나 허가 등을 적용하는 대상으로 사용자만을 고려하고 있으므로 실제의 응용 시스템 상에서 정확한 접근통제를 위해서는 사용자뿐만 아니라 주체 및 객체를 추가로 고려할 필요성이 있다. 본 논문에서는 다단계 보안시스템을 위하여 역할기반 접근통제 모델에 사용자, 주체, 객체, 역할에 대한 보안등급을 추가로 고려하여 확장된 역할기반 접근통제 모델 $ERBAC_3$를 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.921-940
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• 2015

In this paper, we investigate the multi-resource allocation problem, a unique feature of which is that the multiple resources can compensate each other while achieving the desired system performance. In particular, power and time allocations are jointly optimized with the target of energy efficiency under the resource-limited constraints. Different from previous studies on the power-time tradeoff, we consider a multi-server case where the concurrent serving users are quantitatively restricted. Therefore user selection is investigated accompanying the resource allocation, making the power-time tradeoff occur not only between the users in the same server but also in different servers. The complex multivariate optimization problem can be modeled as a variant of 2-Dimension Bin Packing Problem (V2D-BPP), which is a joint non-linear and integer programming problem. Though we use state decomposition model to transform it into a convex optimization problem, the variables are still coupled. Therefore, we propose an Iterative Dual Optimization (IDO) algorithm to obtain its optimal solution. Simulations show that the joint multi-resource allocation algorithm outperforms two existing non-joint algorithms from the perspective of energy efficiency.

• 한국조경학회지
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• 제34권3호
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• pp.23-31
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• 2006

Multi-sensory design results from sensory design paradigm and image centricism, which stimulates 5 sensation; visual, auditory, haptic, smell and taste sensation when we experience environment. This is helpful for designing outdoor space considering integrated sensation not only visual and auditory sensation as well as for improving visitor's satisfaction. Therefore, this study mainly intended to analyse the multi-sensory preference and the image influence of outdoor leisure space. For these purpose, this study selected 3 leisure spaces around Seoul city; Gwan-ak mountain(the type oriented natural resource), Insa-dong(the type oriented cultural resource) and Seoul land as theme park(the type oriented facility) and a survey was performed with a total of 204 visitors at the above spaces in winter and summer. The results of this study indicate that visual sensation was evaluated most high at 3 outdoor leisure spaces in both winter and summer. Visitors at Gwan-ak mountain and Seoul land prefer visual and haptic sensation, but visitors at Insa-dong prefer visual and haptic sensation in summer, visual and taste sensation in winter. Above all, this study led the designer to consider diverse sensation to access leisure space, especially haptic sense, which can be an effective design strategy to satisfy visitors.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권10호
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• pp.4117-4135
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• 2020

Due to the angle of view, illumination and scene diversity, real-time dynamic face detection and recognition is no small difficulty in those unrestricted environments. In this study, we used the intrinsic correlation between detection and calibration, using a multi-task cascaded convolutional neural network(MTCNN) to improve the efficiency of face recognition, and the output of each core network is mapped in parallel to a compact Euclidean space, where distance represents the similarity of facial features, so that the target face can be identified as quickly as possible, without waiting for all network iteration calculations to complete the recognition results. And after the angle of the target face and the illumination change, the correlation between the recognition results can be well obtained. In the actual application scenario, we use a multi-camera real-time monitoring system to perform face matching and recognition using successive frames acquired from different angles. The effectiveness of the method was verified by several real-time monitoring experiments, and good results were obtained.

• 대한전자공학회논문지TC
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• 제44권5호
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• pp.33-39
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• 2007

본 논문은 cognitive radio (CR) 기능을 갖는 무선 멀티홉 릴레이 네트워크의 throughput 용량에 대한 연구 결과이다. 본 논문에서는 TDMA/FDMA에 기반한 프레임 구조를 갖는 릴레이가 기지국과 통신할 때 CR 기술을 이용하여 현재 사용되고 있지 않는 주파수 자원을 측정하여 동적으로 이용하는 시스템을 제안하고 이의 throughput 용량 모델을 제안 하였다. 특히, 본 논문에서는 Utilization factor를 이용하여 제안된 시스템을 위한 throughput 용량 모델을 제안하였다. 해석 모델링 결과 본 논문에서 제안한 CR 기반 멀티홉 릴레이 시스템은 throughput 용량을 매우 향상하는 결과를 보였다.

• 폴리머
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• 제32권4호
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• pp.322-327
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• 2008

본 연구에서 제조한 다중층 펠렛은 수팽윤성 고분자를 포함하는 시드층, 모델 약물인 독사조신을 함유한 약물층, 약물의 방출을 제어하는 다공성막 그리고 지질층으로 구성되어 있으며, 유동층 코팅 방법을 이용하여 제조하였다. 펠렛을 구성하는 각각의 층에 다양한 특성을 가지는 고분자들의 블렌딩에 따른 독사조신의 약물방출 거동을 확인하기 위하여 히드록시프로필메틸셀룰로오스(HPMC)와 에틸셀룰로오스(EC)의 양을 달리하여 약물층을 제조하였고, 셀룰로오스 아세테이트(CA)와 $Eudragit^{(R)}$ RS의 비율을 달리하여 다공성막을 제조하였다. 그리고 지질층에 의한 방출 거동을 확인하고자 피마자유의 두께를 다르게 하여 펠렛을 제조한 결과, 대략 $1500{\mu}m$의 균일한 크기를 가지는 구형의 펠렛을 얻었다. 수용액에서 용출시험을 통하여 시간에 따른 약물방출량을 확인한 결과, 약물층에 첨가된 고분자 중, EC의 비율과 다공성막에서 CA의 비율이 증가하고, 피마자유층의 두께가 두꺼워지면 약물의 방출이 감소함을 알 수 있었다. 그리고 약물방출을 제어하는데 가장 큰 역할을 하는 다공성막의 다공형성거동 역시 SEM을 통해 확인하였다.

• Structural Engineering and Mechanics
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• 제61권6호
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• pp.747-754
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• 2017

Exact solutions for stresses for an infinite rectangular plate perforated by two circular holes of different radii subjected to uni-axial or bi-axial uniform loads are investigated using the Airy stress function. The hoop stresses occurring at the edge of the circular hole are computed and plotted. Comparisons are made for the stress concentration factors for several types of loading conditions.

• 한국통신학회:학술대회논문집
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• 한국통신학회 2006년도 하계종합학술발표회 논문 초록집
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• pp.563-563
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• 2006

• KIEE International Transactions on Power Engineering
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• 제5A권4호
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• pp.412-415
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• 2005

The recent requirement for faster and more frequent solutions has encouraged the consideration of parallel implementations using decentralized processors. Distributed multi-processor environments can potentially greatly increase the available computational capacity and decrease the communication burden, allowing for faster Optimal Power Flow (OPF) solutions. This paper presents a mathematical approach to implementing distributed OPF using the alternating direction method (ADM) to parallelize the OPF. Several IEEE Reliability Test Systems were adopted to demonstrate the proposed algorithm.

• 비만대사연구학술지
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• 제1권2호
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• pp.47-52
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• 2022

Digital therapeutics (DTx) are emerging as a novel solution to improve lifestyle and prevent non-communicable diseases. Obesity is a complex, multi-factorial, chronic condition that requires patient-centered lifestyle modification. DTx, such as mobile applications and wearables, may offer easily accessible, efficient, and personalized care in the field of obesity and metabolic diseases. Yet, there is controversy over its clinical usefulness. This review will provide a comprehensive overview of DTx, including its potential role and current limitation in obesity care, based on recent literature.