• 대한간호학회지
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• 제32권2호
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• pp.243-253
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• 2002

The purpose of this study was to develop Nurse's Suffering Experience Scale and to test the reliability and validity of the instrument. Method: The subjects used to verify the scale's reliability and validity were 220 nurses who were taking care of the end stage cancer patients, while working at university and general hospitals in Daegu and Kyungbuk province from April 20. to July 10, 2001. The data was analyzed by the SPSS/WIN 8.0 program. Results: A factor analysis was conducted, and items that had a factor loading more than .40, and an eigen value more than 1.0. were selected. The factor analysis classified a total of seven factors statistically, and it's communality was 44%. The explanation of factors based on the conceptual framework and item content are as follows: The first factor was expanding self consciousness, the second factor was forming empathy with family, the third factor was professional challenge, the fourth factor was change of values, the fifth factor was spiritual sublimation, the sixth factor was helplessness, and finally the seventh factor was rejection to death. Cronbach's coefficient to test reliability of the scale was .8665 for total of 44 items. The Scale for Nurse's Suffering Experience developed in the study was identified as a tool with a high degree of reliability and validity. Therefore this scale can be effectively utilized for the evaluation of the degree of nurse's suffering experience in clinical settings.

• 한국항행학회논문지
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• 제14권1호
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• pp.119-126
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• 2010

지난 30여년간 개발소프트웨어의 잔여결함, 결함률 및 신뢰도와 같은 신뢰도 척도를 분석하기 위해 소프트웨어의 신뢰도 성장 모델이 개발되어 왔다. 이들 대부분은 개발중 검출되는 소프트웨어의 오류가 완벽하게 수정되는 것으로 가정하였다. 즉, 이들은 테스트중에 검출되는 오류가 완벽하게 제거되는 것을 가정하여 그들의 연구를 진행해왔던 것이다. 그러나 오류를 검출하는 것이 어려울 뿐만 아니라 그 과정에서 새로운 오류가 도입되기도 하기 때문에 오류를 완벽하게 제거하기는 대단히 어렵다. 따라서 본 논문에서는 그동안 가장 보편 타당한 것으로 평가되어 왔던 웨이불형과 비교하여 로지스틱 테스트 노력함수를 적용한 불왼전한 소프트웨어의 테스트 노력을 제안하여 연구 검토한다.

• 전기학회논문지P
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• 제58권4호
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• pp.410-415
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• 2009

With the implementation of electric power industry reform, the utilities are looking for effective ways to improve the economic efficiency. One area in particular, the equipment maintenance, is being scrutinized for reducing costs while keeping a reasonable level of the reliability in the overall system. Here the conventional RCM requires the tradeoff between the upfront maintenance costs and the potential costs of losing loads. In this paper we describe the issues related to applying so-called the "Reliability-centered Maintenance" (RCM) method in managing electric power distribution equipment. The RCM method is especially useful as it explicitly incorporates the cost-tradeoff of interest, i.e. the upfront maintenance costs and the potential interruption costs, in determining which equipment to be maintained and how often. In comparison, the "Time-based Maintenance" (TBM) method, the traditional method widely used, only takes the lifetime of equipment into consideration. In this paper, the modified Markov model for maintenance is developed. First, the existing Markov model for maintenance is explained and analyzed about transformer and circuit breaker, so on. Second, developed model is introduced and described. This model has two different points compared with existing model: TVFR and nonlinear customer interruption cost (CIC). That is, normal stage at the middle of bathtub curve has not CFR but the gradual increasing failure rate and the unit cost of CIC is increasing as the interruption time is increasing. The results of case studies represent the optimal maintenance interval to maintain the equipment with minimum costs. A numerical example is presented for illustration purposes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권7호
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• pp.1585-1609
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• 2013

Over recent years, enormous amounts of research in wireless sensor networks (WSNs) have been conducted, due to its multifarious applications such as in environmental monitoring, object tracking, disaster management, manufacturing, monitoring and control. In some of WSN applications dependent the energy-efficient and link reliability are demanded. Hence, this paper presents a routing protocol that considers these two criteria. We propose a new mechanism called Reliable Routing Scheme for Energy-Balanced (RRSEB) to reduce the packets dropped during the data communications. It is based on Swarm Intelligence (SI) using the Ant Colony Optimization (ACO) method. The RRSEB is a self-adaptive method to ensure the high routing reliability in WSNs, if the failures occur due to the movement of the sensor nodes or sensor node's energy depletion. This is done by introducing a new method to create alternative paths together with the data routing obtained during the path discovery stage. The goal of this operation is to update and offer new routing information in order to construct the multiple paths resulting in an increased reliability of the sensor network. From the simulation, we have seen that the proposed method shows better results in terms of packet delivery ratio and energy efficiency.

• 한국가스학회지
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• 제22권6호
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• pp.52-58
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• 2018

신뢰도 기반 접근법(RBDA)에서, 신뢰도 목표는 설계 및 유지관리 단계에서 관계되는 한계상태를 충족할 수 있는 정도의 안전 수준을 가지는 지 확인하기 위해서 사용된다. 우리나라의 경우 가연성 가스 배관에 대한 신뢰도 목표는 아직 개발되거나 활용되지 못하고 있다. 다만 신뢰도 목표 대신에 사회적 위험과 개인적 위험과 같은 위험 측정지표에 대한 허용가능(tolerable) 판단기준이 배관의 위험관리에 적용되어 왔다. 본 논문에서는 고압천연가스 배관에 대한 정량적 위험평가 시 판단기준으로 삼는 사회적, 개인적 위험 판단기준을 사용하여 신뢰도 기반 접근법의 핵심요소인 목표 신뢰도를 개발하는 절차를 소개하고 자 한다. 또한 소개된 절차를 통해 천연가스와 수소가스 수송배관에 대한 신뢰도 목표를 제안한다.

• ETRI Journal
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• 제44권3호
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• pp.400-412
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• 2022

In cognitive radio networks (CRNs), the computational complexity of resource allocation algorithms is a significant problem that must be addressed. However, the high computational complexity of the optimal solution for tackling resource allocation in CRNs makes it inappropriate for use in practical applications. Therefore, this study proposes a power-based pricing algorithm (PPA) primarily to reduce the computational complexity in downlink CRN scenarios while restricting the interference to primary users to permissible levels. A two-stage approach reduces the computational complexity of the proposed mathematical model. Stage 1 assigns subcarriers to the CRN's users, while the utility function in Stage 2 incorporates a pricing method to provide a power algorithm with enhanced reliability. The PPA's performance is simulated and tested for orthogonal frequency-division multiplexing-based CRNs. The results confirm that the proposed algorithm's performance is close to that of the optimal algorithm, albeit with lower computational complexity of O(M log(M)).

• 정보보호학회논문지
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• 제33권3호
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• pp.577-589
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• 2023

국방부는 국방혁신 4.0 계획에 기반한 첨단과학기술군 육성을 위해 AI를 향후 전력 증강의 핵심 기술로 활용할 계획이다. 그러나 AI의 특성에 따른 보안 위협은 AI 기반의 국방정보시스템에 실질적인 위협이 될 수 있다. 이를 해소하기 위해서는 최초 개발 단계에서부터 체계적인 보안 활동의 수행을 통한 보안 내재화가 필요하다. 이에 본 논문에서는 AI 기반 국방정보시스템 개발 시 단계별로 수행해야 하는 보안 활동 수행 방안을 제안한다. 이를 통해 향후 국방 분야에 AI 기술 적용에 따른 보안 위협을 예방하고 국방정보시스템의 안전성과 신뢰성을 확보하는데 기여할 수 있을 것으로 기대한다.

• Geomechanics and Engineering
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• 제29권2호
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• pp.193-205
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• 2022

The face stability of shield tunnelling is the most important control index for safety risk management. Based on the reliability of the transparent clay (TC) model test, a series of TC model tests under different buried depth were conducted to investigate the progressive failure mechanism of tunnel face. The support pressure was divided into the rapid descent stage, the slow descent stage and the basically stable stage with company of the local failure and integral failure in the internal of the soil during the failure process. The relationship between the support pressure and the soil movement characteristics of each failure stage was defined. The failure occurred from the soil in front of the tunnel face and propagated as the slip zone and the loose zone. The fitted formulas were proposed for the calculation of the failure process. The failure mode in clay was specified as the basin shape with an inverted trapezoid shape for shallow buried and appeared as the basin shape with a teardrop-like shape in deep case. The implications of these findings could help in the safety risk management of the underground construction.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권3호
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• pp.494-507
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• 2011

In this paper, we propose two schemes to reduce the complexity of fixed-complexity sphere decoder (FSD) algorithm in the ordering and tree-search stages, respectively, while achieving quasi-ML performance. In the ordering stage, we propose a QR-decomposition-based FSD signal ordering based on the zero-forcing criterion (FSD-ZF-SQRD) that requires only a few number of additional complex flops compared to the unsorted QRD. Also, the proposed ordering algorithm is extended using the minimum mean square error (MMSE) criterion to achieve better performance. In the tree-search stage, we introduce a threshold-based complexity reduction approach for the FSD depending on the reliability of the signal with the largest noise amplification. Numerical results show that in 8 ${\times}$ 8 MIMO system, the proposed FSD-ZF-SQRD and FSD-MMSE-SQRD only require 19.5% and 26.3% of the computational efforts required by Hassibi's scheme, respectively. Moreover, a third threshold vector is outlined which can be used for high order modulation schemes. In 4 ${\times}$ 4 MIMO system using 16-QAM and 64-QAM, simulation results show that when the proposed threshold-based approach is employed, FSD requires only 62.86% and 53.67% of its full complexity, respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권2호
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• pp.330-343
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• 2011

In this paper, we propose two schemes to reduce the complexity of fixed-complexity sphere decoder (FSD) algorithm in the ordering and tree-search stages, respectively, while achieving quasi-ML performance. In the ordering stage, we propose a QR-decomposition-based FSD signal ordering based on the zero-forcing criterion (FSD-ZF-SQRD) that requires only a few number of additional complex flops compared to the unsorted QRD. Also, the proposed ordering algorithm is extended using the minimum mean square error (MMSE) criterion to achieve better performance. In the tree-search stage, we introduce a threshold-based complexity reduction approach for the FSD depending on the reliability of the signal with the largest noise amplification. Numerical results show that in $8{\times}8$ MIMO system, the proposed FSD-ZF-SQRD and FSD-MMSE-SQRD only require 19.5% and 26.3% of the computational efforts required by Hassibi’s scheme, respectively. Moreover, a third threshold vector is outlined which can be used for high order modulation schemes. In $4{\times}4$ MIMO system using 16-QAM and 64-QAM, simulation results show that when the proposed threshold-based approach is employed, FSD requires only 62.86% and 53.67% of its full complexity, respectively.