• 한국항해항만학회지
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• 제34권2호
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• pp.145-152
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• 2010

The management of safety at sea is based on a set of internationally accepted regulations and codes, governing or guiding the design and operation of ships. The regulations most directly concerned with human safety and protection of the environment are, in general, agreed internationally through the International Maritime Organization(IMO). IMO has continuously dealt with safety problems and, recognized that the human element is a key factor in both safety and pollution prevention issues(IMO, 2010). This paper proposes a human error analysis methodology which is based on the human error taxonomy and theories (SHELL model, GEMS model and etc.) that were discussed in the IMO guidelines for the investigation of human factors in marine casualties and incidents. In this paper, a cognitive process model, a human error analysis technique and a marine accident causal chains focused on human factors are discussed, and towing vessel collision accidents are analyzed as a case study in order to examine the applicability of the human error analysis technique to marine accidents. Also human errors related to those towing vessel collision accidents and their underlying factors are discussed in detail.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권8호
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• pp.2663-2674
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• 2014

For cognitive radio sensor networks (CRSNs) that use underlay-based spectrum access, the location of the primary user (PU) plays an important role in the power control of the secondary users (SUs), because the SUs must keep the minimum interference level required by the PU. Received signal strength (RSS)-based localization schemes provide low-cost implementation and low complexity, thus it is suitable for the PU localization in CRSNs. However, the RSS-based localization schemes have a high localization error because they use an inexact path loss exponent (PLE). Thus, applying a RSS-based localization scheme into the PU localization would cause a high interference to the PU. In order to reduce the localization error and improve the channel reuse rate, we propose a RSS-based PU localization scheme that uses distance calibration for CRSNs using underlay model-based spectrum access. Through the simulation results, it is shown that the proposed scheme can provide less localization error as well as more spectrum utilization than the RSS-based PU localization using the mean and the maximum likelihood calibration.

• 성인간호학회지
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• 제26권1호
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• pp.34-45
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• 2014

Purpose: The purpose of this study was to investigate the effect of laughter therapy and cognitive reinforcement program on self-efficacy, depression and cognitive functions of the elderly with mild cognitive impairments (MCI). Methods: The study design was a non-equivalent control group pre and posttest design. Thirty-six subjects over the age of 65 with a diagnosis of mild cognitive impairment were assigned either to a treatment or a comparison group. Data were collected from February 7 to March 27, 2012 in the dementia supporting center. An eight week treatment program that included laughter therapy coupled with a cognitive reinforcing program including hand exercise, laughter dance routine, laughter technic and cognitive training for attention, memory, orientation and execution skill. Results: MoCA-K (t=-6.86, p<.001) and Stroop test CW correct (t=-2.54, p=.008), self-efficacy (t=-3.62, p=.001) in the treatment group were significantly higher than those of the comparison group. Reported depression (t=2.29, p=.014), Stroop test CW error (U=53.50, p<.001) in the treatment group was significantly less than the comparison group. Conclusion: In this study, the treatment was effective in improving self-efficacy, cognitive function and reducing depression in the elderly with MCI.

• International Journal of Internet, Broadcasting and Communication
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• 제8권3호
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• pp.69-77
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• 2016

Maximum utilization of unused license spectrum is one of key factor in cognitive radio network which can handle the large number of systems and devices connected on smart grid AMI network. The central intelligence control system has responsibility to accept new technologies and users for automation. To ensure a reliable communication in smart grid system through cognitive network, a minimum mean square error (MSE) signal using unused licensed spectrum (or frequency) is necessary to be detected with small decision error. In this paper, we introduce a user control wireless smart grid system with minimum MSE using LMS algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권4호
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• pp.649-664
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• 2011

Cooperative spectrum sensing (CSS) with decision fusion is considered as a key technology for tackling the challenges caused by fading/shadowing effects and noise uncertainty in spectrum sensing in cognitive radio. However, most existing solutions assume an error-free decision transmission, which is obviously not the case in realistic scenarios. This paper extends the general decision-fusion-based CSS scheme by considering the fading/shadowing effects and noise corruption in the common control channels. With this more practical model, the fusion centre first estimates the local decisions using a binary minimum error probability detector, and then combines them to get the final result. Theoretical analysis and simulation of this CSS scheme are performed over typical channels, which suggest some performance deterioration compared with the pure case that assumes an error-free decision transmission. Furthermore, the fusion strategy optimization in the proposed cooperation model is also investigated using the Bayesian criteria. The numerical results show that the total error rate of noisy CSS is higher than that of the pure case, and the optimal values of fusion parameter in the counting rule under both cases decrease as the local detection threshold increases.

• 한국기계가공학회지
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• 제19권10호
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• pp.68-73
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• 2020

The proportion of airline accidents caused by human factors is steadily increasing. The aviation industry has made considerable progress in reducing the accident rate; however, since the early 1980s, the accident rate has remained constant. Due to airspace congestion, the safety margins of these existing safety promotion methods are gradually decreasing; thus, new methods to prevent accidents and quasi-accidents must be devised. Causative factors of aviation accidents include increased air traffic due to increased air demand, increased cumulative working hours due to long-distance flights, and complicated flight environments. Accidents often occur when several small errors accumulate in the normal course of operation, rather than after a single error. Accordingly, in this study, the impacts on air navigation due to human error by aviation maintenance personnel and varying international standards (i.e., KOCA vs. F.A.A vs. EASA) analyzed, and the relationship between human decision-making and behavior was investigated. The resulting safety analysis and alternatives were presented to prevent aviation maintenance accidents and cognitive ergonomics errors.

• 한국통신학회논문지
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• 제40권2호
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• pp.253-263
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• 2015

최근 다수의 후 순위 사용자(Secondary User)가 각각의 검출 결과를 융합 센터(Fusion Center)에 보고하여 대역 검출의 성능을 향상시키기 위한 협력 대역 검출 기법이 이루어지고 있다. 또한 선 순위 사용자(Primary User)에게 할당된 주파수 대역을 융합 센터가 공유하는 인지 무선(Cognitive Radio)기술이 개발되고 있다. 이 논문에서는 분산 협력 대역 검출 환경에서 후 순위 사용자의 검출 정보가 융합 센터로 보고되는 채널의 오류 확률을 고려한 기존 분산 협력 대역 검출 기법의 성능 저하를 보완하는 새로운 분산 협력 대역 검출 기법을 제안하였다. 또한 분산 협력 대역 검출 기법의 오류 확률을 최소화 하는 검출 문턱값의 최적화 방법을 수식의 유도를 통해 제안하였다. 최적의 검출 문턱값은 분산 협력 대역 검출의 성능을 최대화 하는 것을 확인하였다.

• 인지과학
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• 제33권4호
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• pp.205-228
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• 2022

본 연구는 인간 로봇 상호작용에서 로봇의 사회적이고 관계적인 행동 유형이 인간의 인식에 끼치는 영향을 확인하고자 하였다. 이를 위한 실험에서는 연구 참여자들이 로봇 나오가 인간과 상호작용 하면서 로봇이 오류를 일으키고 신뢰회복을 위한 행동을 영상으로 시청한 후 로봇에 대한 신뢰를 평가하였다. 신뢰회복 행동은 로봇이 오류를 인정하고 사과하는 내부 귀인, 오류가 있었음을 사과하지만 외부로 귀인하는 조건, 오류 자체를 부인, 오류에 대해 아무런 사후 행동을 하지 않는 비 행동 조건으로 설정하였다. 이후 로봇에 대한 인간의 평가를 3가지 측면에서 분석하였다. 첫째, 로봇의 유능함과 정직성에 기반한 신뢰, 둘째 로봇에 대한 지각된 유능함과 정직성, 그리고 로봇의 오류로 인한 신뢰 위반에 대하여 오류의 심각성을 어떻게 지각하는지 탐색하였다. 실험의 결과는 3가지 모든 경우에서 로봇이 사과하지 않을 때보다 사과할 때 오류가 덜 심각하다고 지각하였으며 로봇에 대한 능력 또한 높이 평가하였다. 이러한 연구 결과는 로봇의 행동유형과 오류 극복 방법에 따라 로봇에 대한 인간의 태도가 민감하게 반응 할 수 있다는 근거를 제공하며 로봇에 대한 인간의 지각이 변할 수 있음을 시사한다. 특히 로봇이 스스로의 오류를 인정하고 사과하는 것이 더 신뢰를 높인다는 결과는 로봇이 인간처럼 사회적이고 매너있는 행동을 통해 긍정적인 인간 로봇상호작용을 증진시킬 수 있음을 보여준다.

• 한국항공운항학회지
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• 제26권1호
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• pp.10-24
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• 2018

This paper tried to analyze the response of air traffic controller(ATC) against abnormal situations using survey based on cognitive strategies suggested by Malakis et al.(2010). The survey designed to empirically analyze the effect of the cognitive strategy factors on organizational effectiveness. The main purpose of this research was as follows: First, it was analyzed both the individual-scale and team-scale factors which constructed the cognitive strategy against abnormal situations. Secondly, how seriously impact the ATC's cognitive strategies on their organizational effectiveness. The organizational effectiveness was divided into such two latent variables as job absorption and job satisfaction. According to the a analysis, it was proven that premeditated act of ATC had a positive significant effect on team-scale cognitive strategies such as teamwork, communication and error management. Moreover, it was found out the team-scale cognitive strategies had also a positive significant effect on job absorption. On the other hands, individual-scale cognitive strategies had no or negative effect on job absorption. Job absorption was proven to have a significant effect on job satisfaction of ATC.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권2호
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• pp.782-795
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• 2019

Safety is always acritical focus of exploration of ocean resources, and it is well recognized that human factor is one of the major causes of accidents and breakdowns. Our research developed a dynamic human reliability assessment approach, Predicted Mean Vote-Cognitive Reliability and Error Analysis Method (PMV-CREAM), that is applicable to monitoring the cognitive reliability of oceanauts during deep-sea missions. Taking into account the difficult and variable operating environment of manned submersibles, this paper analyzed the cognitive actions of oceanauts during the various procedures required by deep-sea missions, and calculated the PMV index using human factors and dynamic environmental data. The Cognitive Failure Probabilities (CFP) were calculated using the extended CREAM approach. Finally, the CFP were corrected using the PMV index. This PMV-CREAM hybrid model can be utilized to avoid human error in deep-sea research, thereby preventing injury and loss of life during undersea work. This paper verified the method with "Jiaolong" manned submersible 7,000 m dive test. The"Jiaolong" oceanauts CR(Corrected CFP) is dynamic from 3.0615E-3 to 4.2948E-3, the CR caused by the environment is 1.2333E-3. The result shown the PMV-CREAM method could describe the dynamic human reliability of manned submersible caused by thermal environment.