• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.717-719
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• 2003

Recently Neural Network techniques have widely used in adaptive and learning control schemes for production systems. However, generally it costs a lot of time for learning in the case applied in control system. Furthermore, the physical meaning of neural networks constructed as a result is not obvious. And in practice since it is difficult to the PID gains suitably lots of researches have been reported with respect to turning schemes of PID gains. A Neural Network-based PID control scheme is proposed, which extracts skills of human experts as PID gains. This controller is designed by using three-layered neural networks. The effectiveness of the proposed Neural Network-based PID control scheme is investigated through an application for a production control system. This control method can enable a plant to operate smoothy and obviously as the plant condition varies with any unexpected accident.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
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• pp.89-91
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• 2004

Recently Neural Network techniques have widely used in adaptive and learning control schemes for production systems. However, generally it costs a lot of time for learning in the case applied in control system. Furthermore, the physical meaning of neural networks constructed as a result is not obvious. And in practice since it is difficult to the PID gains suitably lots of researches have been reported with respect to turning schemes of PID gains. A Neural Network-based PID control scheme is proposed, which extracts skills of human experts as PID gains. This controller is designed by using three-layered neural networks. The effectiveness of the proposed Neural Network-based PID control scheme is investigated through an application for a production control system. This control method can enable a plant to operate smoothy and obviously as the plant condition varies with any unexpected accident. This paper goal is convergence speed progress about applied gain of PID controller using the neural networks.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2006년도 학술발표회 논문집
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• pp.589-596
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• 2006

Torsional behavior of eccentric structures under seismic loading may cause stress and/or strain concentration, which result in the failure of the structures in an unexpected manner. This study propose how to assess the seismic capacity of plan-irregular RC wall structures. The seismic capacities ate expressed in terms of lateral displacement capacity of each wall. The seismic demands for displacement are assessed by so called displacement-based design approach. Those seismic capacity and demands are combined D-R coordinate, which is made up of lateral displacement and rotation angle. To expand these concepts to the inelastic region the adaptive modal analysis method is used. In addition, the failure mechanisms including torsional failure are defined on D-R coordinate. Finally, seismic assessments of two 3-story plan-irregular wall structures ate presented.

• ETRI Journal
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• 제43권6호
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• pp.1004-1012
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• 2021

The collaboration productively interacting between multi-agents has become an emerging issue in real-world applications. In reinforcement learning, multi-agent environments present challenges beyond tractable issues in single-agent settings. This collaborative environment has the following highly complex attributes: sparse rewards for task completion, limited communications between each other, and only partial observations. In particular, adjustments in an agent's action policy result in a nonstationary environment from the other agent's perspective, which causes high variance in the learned policies and prevents the direct use of reinforcement learning approaches. Unexpected social loafing caused by high dispersion makes it difficult for all agents to succeed in collaborative tasks. Therefore, we address a paradox caused by the social loafing to significantly reduce total returns after a certain timestep of multi-agent reinforcement learning. We further demonstrate that the collaborative paradox in multi-agent environments can be avoided by our proposed effective early stop method leveraging a metric for social loafing.

• 대한신경집중치료학회지
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• 제11권2호
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• pp.119-123
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• 2018

Background: Since the first report of a rapidly resolved subdural hemorrhage (SDH) in 1986, few additional case reports have been presented in the literature. Case Report: An 82-year-old female patient presented with a SDH over the left convexity. The SDH was removed via catheter drainage through a burr hole trephination. Post-operative computed tomography (CT) following 300 mL drainage from the chronic SDH demonstrated a newly developed SDH along the right convexity. A follow-up CT performed 2 hours later revealed an unexpected significant resolution of the acute SDH. Conclusion: The spontaneous resolution of acute SDH is believed to result from redistribution by washout of the hematoma by cerebrospinal fluid dilution. However, its exact pathophysiology is not well understood. When surgical evacuation is considered in acute SDH, conservative management should also be considered because spontaneous resolution of hemorrhage remains a possibility.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1240-1240
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• 2022

Construction projects are fraught with risks from cost or other overruns to accidents along with other issues. This is true whether the relevant organization is an owner, general contractor, CM, specialty-trade contractor, or other entity. When cost issues or other issues confront arise, how should an organization proceed whether attempting to gain additional compensation in terms of cost/other damages or protecting the same against such claims if they do not appear to be warranted? Enter construction cost forensics. This presentation will focus on strategies/techniques with construction cost forensics in these areas in order to be successful. Covered techniques include those to develop and analyze claims including fundamental construction cost analysis techniques. When an unexpected event disrupts a construction project, using sound analytical methods to identify the cause and quantify the extent of the issue will be important for negotiating a fair result or for obtaining a successful outcome in arbitration or litigation. Key examples of uncovering issues via construction cost forensics will be covered in this presentation.

• 한국가시화정보학회지
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• 제21권1호
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• pp.26-30
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• 2023

Interaction of a droplet and substrate is important to determine the coating and final deposition pattern in inkjet printing system. In particular, an accurate deposition of the droplet should be guaranteed for high-resolution patterning. In this study, we performed high-speed shadowgraph experiments on droplet train impact in inkjet system. From the high-speed images, we observed an unexpected bouncing phenomenon. We have found two factors affecting bouncing regime; the Weber number and the curvature of deposited droplet. Experimental results indicate that there is a critical curvature diameter of deposited droplet, which splits into bouncing and merging regime. From this result, we obtained a power-law behavior between the Weber number and the curvature. The understanding of bouncing phenomena helps to improve the accuracy and productivity of inkjet printing.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.97-100
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• 2015

Analysis of construction tender documents in overseas projects is a very important issue from a risk management point of view. Unfortunately, majority of construction firms are biased by winning contracts without in-depth analysis of tender documents. As a result, many contractors have incurred loss in overseas projects. Although a lot of risk analysis techniques have been introduced, most of them focus project's external unexpected risks such as country conditions and owner's financial standing. However, because those external risks are difficult to control and take preemptive action, we need to concentrate on project inherent risks. Based on this premise, this paper proposes a project-oriented risk mining approach which could detect and extract project risk factors automatically before they are materialized and assess them. This study presents a methodology regarding how to extract potential risks which exist in owner's project requirements and project tender documents using state of the art data analysis method such as text mining, data mining, and information visualization. The project-oriented risk mining approach is expected to effectively reflect project characteristics to the project risk management and could provide construction firms with valuable business intelligence.

• Communications for Statistical Applications and Methods
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• 제31권1호
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• pp.129-142
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• 2024

In various industries, especially manufacturing and chemical industries, it is often observed that the distribution of a specific process, initially having followed a normal distribution, becomes skewed as a result of unexpected causes. That is, a process deviates from a normal distribution and becomes a skewed distribution. The skew-normal (SN) distribution is one of the most employed models to characterize such processes. The shape of this distribution is determined by the asymmetry parameter. When this parameter is set to zero, the distribution is equal to the normal distribution. Moreover, when there is a shift in the asymmetry parameter, the mean and variance of a SN distribution shift accordingly. In this paper, we propose procedures for monitoring the asymmetry parameter, based on the statistic derived from the noncentral t-distribution. After applying the statistic to Shewhart and the exponentially weighted moving average (EWMA) charts, we evaluate the performance of the proposed procedures and compare it with previously studied procedures based on other skewness statistics.

• 여성건강간호학회지
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• 제15권1호
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• pp.43-53
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• 2009

Purpose: This study was to identify what experience meant for the wives that attempted IVF-ET(In Vitro Fertilization-Embryo Transfer) program due to the spouse's infertility and provide fundamental materials to improve nursing interventions. Method: Giorgi's phenomenological method was employed, the subjects were five wives who had ever attempted IVF-ET program due to the infertility of their spouses. In-depth interview and observation method were utilized to gather information from April to December 2003. Result: The significant results from analyzing the interviews can be grouped into 34 themes, 8 categories. The essential themes for the experiences of the wives were 'shocked by the unbelievable reality', 'can't give up the connection to the blood', 'Lack of social education on pregnancy, and childbirth', 'self-pity', 'feelings of both families', 'Being afraid of the unexpected result', 'physical and mental agony', 'Positively coping with the reality. Conclusion: The results show that infertility is not a mere personal matter, and infertile people, their families and society should team up with in tackling it. The physical, psychological and social problems triggered by infertility could be ironed out by making both personal and collaborative approaches to that.