• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권11호
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• pp.3892-3912
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• 2021

The recent rapid growth of mobile network traffic places multi-access edge computing in an important position to reduce network load and improve network capacity and service quality. Contrasting with traditional mobile cloud computing, multi-access edge computing includes a base station cooperative cache layer and user cooperative cache layer. Selecting the most appropriate cache content according to actual needs and determining the most appropriate location to optimize the cache performance have emerged as serious issues in multi-access edge computing that must be solved urgently. For this reason, a cache placement algorithm based on comprehensive utility in big data multi-access edge computing (CPBCU) is proposed in this work. Firstly, the cache value generated by cache placement is calculated using the cache capacity, data popularity, and node replacement rate. Secondly, the cache placement problem is then modeled according to the cache value, data object acquisition, and replacement cost. The cache placement model is then transformed into a combinatorial optimization problem and the cache objects are placed on the appropriate data nodes using tabu search algorithm. Finally, to verify the feasibility and effectiveness of the algorithm, a multi-access edge computing experimental environment is built. Experimental results show that CPBCU provides a significant improvement in cache service rate, data response time, and replacement number compared with other cache placement algorithms.

• Geomechanics and Engineering
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• 제18권4호
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• pp.439-448
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• 2019

The bearing capacity of roadside support is the key problem in gob-side entry retaining technology. To study the cooperative bearing characteristics of the roof-roadside support-floor along the gob-side entry retaining, a mechanical model of the composite structure of the roof-roadside support-floor was first established. A method for determining the structural parameters of gob-side entry retaining was then proposed. Based on this model, adaptability analysis of roadside support was carried out. The results showed that the reasonable width of the gob-side entry roadway was inversely proportional to the mining height, and directly proportional to the bearing strength of the roof and floor. And the reasonable width of the "flexible-hard" roadside support was directly proportional to its own strength, and inversely proportional to the width of the gob-side entry retaining. When determining the position and size of the roadside support along the gob-side entry retaining, the surrounding rock environment should be fully considered. Measured results from case study also show the rationality of the model and calculation method.

• 한국건설관리학회논문집
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• 제16권3호
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• pp.132-142
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• 2015

건설산업은 다양한 참여자를 통해 하나의 시설물을 생산하는 것으로 계약의 망에 의해 움직이는 기업생태계의 특성을 가진다. 그간 국내 건설생산체계는 건설기업간 협력적 관계 형성 미비로 고비용, 저효율을 초래해 왔다. 이에 정부는 다양한 정책적 노력을 기울여 왔으나, 실질적인 협력의 성과는 아직 미흡한 실정이다. 본 연구에서는 기업생태계(business ecosystem)의 시각에서 건설생산체계를 근간으로 하는 건설기업간의 네트워크 방식을 기업생태계로 정의하고, 건설산업의 협력적 기업생태계를 진단하였다. 건설산업의 협력적 기업 생태계 조성을 위해서는 역량형 신뢰 또는 가치공유형 신뢰에 기반을 둔 협력 생태계의 형성이 필요하고, 건설업체간 상호의존도가 높고 협력관계가 지속되어야 하며, 무엇보다도 건설참여자의 수익 공유를 위해 적정공사비를 확보할 수 있는 여건이 마련되어야 한다.

• 한국지능시스템학회논문지
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• 제16권1호
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• pp.72-78
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• 2006

군집 로봇시스템에서 협조 행동을 위기 위해서는 로봇의 센싱과 통신 기능은 필수적이다. 일반적으로 대역적 통신 시스템에서는 로봇의 대수가 증가하면 통신 자원의 제한과 정보의 범람이 발생한다. 따라서 이 경우 지역적 통신방법이 유리하다. 따라서 본 논문에서는 지역적 통신에 의한 정보의 전파 해석을 통하여 최적의 통신 반경을 결정하는 방법을 제안하고, 이를 이용하여 인공면역계에 기반한 군집 로봇시스템의 협조 전략과 군 행동 알고리즘을 제안한다.

• 한국인터넷방송통신학회논문지
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• 제18권2호
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• pp.49-54
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• 2018

본 논문에서는 복호 후 재전송 기반의 중계기 시스템에서 협력 다이버시티와 재머를 사용했을 때의 보안 불능 확률을 연구한다. 협력 다이버시티를 얻기 위해서 수신자와 도청자에서 MRC 기법을 사용한다. MRC 기법을 사용하기 위해서 송신자와 수신자, 송신자와 도청자 사이의 직접 링크를 사용한다. 보안용량을 증가시키기 위해서 의도적인 잡음 신호를 발생 시키는 재머를 사용한다. 재머는 의도적인 잡음을 발생시켜 도청자의 채널 품질을 떨어뜨리고 물리 계층 보안이 실현될 수 있도록 돕는다. 보안 성능을 평가하기 위해서 보안 불능 확률이 사용된다. 시스템은 레일리 페이딩 채널 하에 있다고 가정한다.

• 지역사회간호학회지
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• 제18권4호
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• pp.593-600
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• 2007

Purpose: This research was carried out to present an ideal cooperative model between the public and private health sectors for the management of community dementia patients. Method: In this study a public-private cooperative council was formed, basic data for dementia patients and their families were collected, and a dementia service program was carried out in cooperation between the two sectors. Results: The survey data shows the majority of the registered patients were undergoing a chronic diseases which would make the dementia health service inefficient. The cooperative public-private council adopted the reinforcement of medical service to the public enrolled dementia patients. The intensive medical service program showed effects on the health status of the dementia patients. Conclusion: The results of this study pointed out that change of the health insurance program supportive to the private sectors to be made; a referral system for the public health sector to the private sector should be established; and expanding the capacity of the visiting health program in the public health sector is needed.

• 한국통신학회논문지
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• 제32권12A호
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• pp.1251-1259
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• 2007

A scheme for selecting the mode with the maximum system capacity is proposed for cooperative relaying. Three possible modes are presented based on decode-and-forward relaying, and the time required by each mode is evaluated. Based on these results, a method is then developed for selecting the optimal mode with the minimum time duration (or maximum channel capacity). Computer simulations confirm that the optimal mode outperforms the other modes.

• 비교교육연구
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• 제24권3호
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• pp.1-23
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• 2014

본 연구는 고교 다양화 및 특성화고 육성 정책으로 인해 상대적으로 불이익을 받고 있는 일반고의 교육역량 강화 필요성을 인식하고, 현재 일반고가 안고 있는 문제점 등을 진단하여 장 단기적인 관점에서 경상북도의 일반고 육성방안을 다각적으로 마련 제시하는 데 그 목적이 있다. 이를 위해 먼저, 박근혜정부의 교육정책기조와 경상북도 교육정책 방향, 경북지역 일반고 교육현황, 일반고 교육역량 강화방안의 주요 내용 등을 살펴보았다. 교육부의 일반고 교육역량 강화방안에 기초하여 제시된 경상북도 일반고 교육역량 제고의 주요 추진과제로는 (1) 진로별 맞춤형 교육과정 편성 운영의 자율성 확대, (2) 일반고 학생을 위한 진로직업 교육 확대, (3) 위기학생 지원 프로그램 강화, (4) 일반고 High-up 프로그램 지원 강화 등을 들 수 있다. 이와 같은 일반고 교육역량 강화를 위한 주요 추진과제들이 학교현장에서 성공적으로 정착 운영되기 위해서는 개별 일반고의 지역적 환경과 특성을 고려한 학교단위 책임경영제의 정착, 학교경영에 있어 총체적 질 관리 적용, 그리고 협동적 학교조직문화 형성이 구축되어야 할 것이다. 그리고 글로벌 민주시민 양성, 2009 개정 교육과정에서 추구하는 인간상, 그리고 경상북도교육청에서 제시하고 있는 '새로운 생각과 참된 마음을 지닌 인재'를 육성하기 위한, 즉 경상북도 일반고 교육역량 제고를 위한 구체적인 실천과제와 전략들도 제시하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.3967-3983
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• 2014

The performance of an partial relay selection on the decode-and-forward (DF) mode cognitive radio (CR) relay networks is studied, with some important factors, including the outage probability, the bit error ratio (BER), and the average channel capacity being analyzed. Different from the conventional relay selection schemes, the impact of spectrum sensing process as well as the spectrum utilization efficiency of primary users on the performance of DF-based CR relaying networks has been taken into consideration. In particular, the exact closed-form expressions for the figures of merit such as outage probability, BER, and average channel capacity over independent and identically distributed (i.i.d.) Rayleigh fading channels, have been derived in this paper. The validity of the proposed analysis is proven by simulation, which showed that the numerical results are consistent with the theoretical analysis in terms of the outage probability, the BER and the average channel capacity. It is also shown that the full spatial diversity order can always be obtained at the signal-to-noise ratio (SNR) range of [0dB, 15dB] in the presence of multiple potential relays.

• Steel and Composite Structures
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• 제49권4호
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• pp.381-392
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• 2023

This study experimentally investigates the flexural behavior of steel-UHPC composite slabs composed of an innovative negative Poisson's ratio (NPR) steel plate and Ultra High Performance Concrete (UHPC) slab connected via demountable high-strength bolt shear connectors. Eight demountable composite slab specimens were fabricated and tested under traditional four-point bending method. The effects of loading histories (positive and negative bending moment), types of steel plate (NPR steel plate and Q355 steel plate) and spacings of high-strength bolts (150 mm, 200 mm and 250 mm) on the flexural behavior of demountable composite slab, including failure mode, load-deflection curve, interface relative slip, crack width and sectional strain distribution, were evaluated. The results revealed that under positive bending moment, the failure mode of composite slabs employing NPR steel plate was distinct from that with Q355 steel plate, which exhibited that part of high-strength bolts was cut off, part of pre-embedded padded extension nuts was pulled out, and UHPC collapsed due to instantaneous instability and etc. Besides, under the same spacing of high-strength bolts, NPR steel plate availably delayed and restrained the relative slip between steel plate and UHPC plate, thus significantly enhanced the cooperative deformation capacity, flexural stiffness and load capacity for composite slabs further. While under negative bending moment, NPR steel plate effectively improved the flexural capacity and deformation characteristics of composite slabs, but it has no obvious effect on the initial flexural stiffness of composite slabs. Meanwhile, the excellent crack-width control ability for UHPC endowed composite members with better durability. Furthermore, according to the sectional strain distribution analysis, due to the negative Poisson's ratio effect and high yield strength of NPR steel plate, the tensile strain between NPR steel plate and UHPC layer held strain compatibility during the whole loading process, and the magnitude of upward movement for sectional plastic neutral axis could be ignored with the increase of positive bending moment.