• Title/Summary/Keyword: adaptive model

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Adaptive Control Scheme of Air Tanker Ground Waiting Time Based on a Multi-Server Queuing Model (다중서버 큐잉 모델을 이용한 공중급유기 지상 대기시간 적응적 제어 기법)

  • Sohn, Yong-Sik;Chung, Jong-Moon
    • Journal of Internet Computing and Services
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    • v.23 no.5
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    • pp.33-46
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    • 2022
  • This paper, in order to minimize the ground waiting time of an Air tanker, the queuing theory, that is, a queue that calculates the waiting time under single-server and multi-server situations, was used in the study. Since the national budget and resources are limited, the unlimited increase of the logistics support service team is limited. Therefore, the number of logistic support service teams that can adaptively control the ground waiting time according to the wartime preparation stage or war environment was calculated. The results of this study provide a stipulated standard for calculating the optimal number of air tanker logistic support service teams of the Air Force, providing a basis for the logistical commander to assign logistic support service teams to each stage from peacetime to wartime.

Transfer Learning Technique for Accelerating Learning of Reinforcement Learning-Based Horizontal Pod Autoscaling Policy (강화학습 기반 수평적 파드 오토스케일링 정책의 학습 가속화를 위한 전이학습 기법)

  • Jang, Yonghyeon;Yu, Heonchang;Kim, SungSuk
    • KIPS Transactions on Computer and Communication Systems
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    • v.11 no.4
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    • pp.105-112
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    • 2022
  • Recently, many studies using reinforcement learning-based autoscaling have been performed to make autoscaling policies that are adaptive to changes in the environment and meet specific purposes. However, training the reinforcement learning-based Horizontal Pod Autoscaler(HPA) policy in a real environment requires a lot of money and time. And it is not practical to retrain the reinforcement learning-based HPA policy from scratch every time in a real environment. In this paper, we implement a reinforcement learning-based HPA in Kubernetes, and propose a transfer leanring technique using a queuing model-based simulation to accelerate the training of a reinforcement learning-based HPA policy. Pre-training using simulation enabled training the policy through simulation experience without consuming time and resources in the real environment, and by using the transfer learning technique, the cost was reduced by about 42.6% compared to the case without transfer learning technique.

Common and differential effects of docosahexaenoic acid and eicosapentaenoic acid on helper T-cell responses and associated pathways

  • Lee, Jaeho;Choi, Yu Ri;Kim, Miso;Park, Jung Mi;Kang, Moonjong;Oh, Jaewon;Lee, Chan Joo;Park, Sungha;Kang, Seok-Min;Manabe, Ichiro;Ann, Soo-jin;Lee, Sang-Hak
    • BMB Reports
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    • v.54 no.5
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    • pp.278-283
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    • 2021
  • Our understanding of the differential effects between specific omega-3 fatty acids is incomplete. Here, we aimed to evaluate the effects of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on T-helper type 1 (Th1) cell responses and identify the pathways associated with these responses. Naïve CD4+ T cells were co-cultured with bone marrow-derived dendritic cells (DCs) in the presence or absence of palmitate (PA), DHA, or EPA. DHA or EPA treatment lowered the number of differentiated IFN-γ-positive cells and inhibited the secretion of IFN-γ, whereas only DHA increased IL-2 and reduced TNF-α secretion. There was reduced expression of MHC II on DCs after DHA or EPA treatment. In the DC-independent model, DHA and EPA reduced Th1 cell differentiation and lowered the cell number. DHA and EPA markedly inhibited IFN-γ secretion, while only EPA reduced TNF-α secretion. Microarray analysis identified pathways involved in inflammation, immunity, metabolism, and cell proliferation. Moreover, DHA and EPA inhibited Th1 cells through the regulation of diverse pathways and genes, including Igf1 and Cpt1a. Our results showed that DHA and EPA had largely comparable inhibitory effects on Th1 cell differentiation. However, each of the fatty acids also had distinct effects on specific cytokine secretion, particularly according to the presence of DCs.

An Improved ViBe Algorithm of Moving Target Extraction for Night Infrared Surveillance Video

  • Feng, Zhiqiang;Wang, Xiaogang;Yang, Zhongfan;Guo, Shaojie;Xiong, Xingzhong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.12
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    • pp.4292-4307
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    • 2021
  • For the research field of night infrared surveillance video, the target imaging in the video is easily affected by the light due to the characteristics of the active infrared camera and the classical ViBe algorithm has some problems for moving target extraction because of background misjudgment, noise interference, ghost shadow and so on. Therefore, an improved ViBe algorithm (I-ViBe) for moving target extraction in night infrared surveillance video is proposed in this paper. Firstly, the video frames are sampled and judged by the degree of light influence, and the video frame is divided into three situations: no light change, small light change, and severe light change. Secondly, the ViBe algorithm is extracted the moving target when there is no light change. The segmentation factor of the ViBe algorithm is adaptively changed to reduce the impact of the light on the ViBe algorithm when the light change is small. The moving target is extracted using the region growing algorithm improved by the image entropy in the differential image of the current frame and the background model when the illumination changes drastically. Based on the results of the simulation, the I-ViBe algorithm proposed has better robustness to the influence of illumination. When extracting moving targets at night the I-ViBe algorithm can make target extraction more accurate and provide more effective data for further night behavior recognition and target tracking.

Development of Security Anomaly Detection Algorithms using Machine Learning (기계 학습을 활용한 보안 이상징후 식별 알고리즘 개발)

  • Hwangbo, Hyunwoo;Kim, Jae Kyung
    • The Journal of Society for e-Business Studies
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    • v.27 no.1
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    • pp.1-13
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    • 2022
  • With the development of network technologies, the security to protect organizational resources from internal and external intrusions and threats becomes more important. Therefore in recent years, the anomaly detection algorithm that detects and prevents security threats with respect to various security log events has been actively studied. Security anomaly detection algorithms that have been developed based on rule-based or statistical learning in the past are gradually evolving into modeling based on machine learning and deep learning. In this study, we propose a deep-autoencoder model that transforms LSTM-autoencoder as an optimal algorithm to detect insider threats in advance using various machine learning analysis methodologies. This study has academic significance in that it improved the possibility of adaptive security through the development of an anomaly detection algorithm based on unsupervised learning, and reduced the false positive rate compared to the existing algorithm through supervised true positive labeling.

Application of AI models for predicting properties of mortars incorporating waste powders under Freeze-Thaw condition

  • Cihan, Mehmet T.;Arala, Ibrahim F.
    • Computers and Concrete
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    • v.29 no.3
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    • pp.187-199
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    • 2022
  • The usability of waste materials as raw materials is necessary for sustainable production. This study investigates the effects of different powder materials used to replace cement (0%, 5% and 10%) and standard sand (0%, 20% and 30%) (basalt, limestone, and dolomite) on the compressive strength (fc), flexural strength (fr), and ultrasonic pulse velocity (UPV) of mortars exposed to freeze-thaw cycles (56, 86, 126, 186 and 226 cycles). Furthermore, the usability of artificial intelligence models is compared, and the prediction accuracy of the outputs is examined according to the inputs (powder type, replacement ratio, and the number of cycles). The results show that the variability of the outputs was significantly high under the freeze-thaw effect in mortars produced with waste powder instead of those produced with cement and with standard sand. The highest prediction accuracy for all outputs was obtained using the adaptive-network-based fuzzy inference system model. The significantly high prediction accuracy was obtained for the UPV, fc, and fr of mortars produced using waste powders instead of standard sand (R2 of UPV, fc and ff is 0.931, 0.759 and 0.825 respectively), when under the freeze-thaw effect. However, for the mortars produced using waste powders instead of cement, the prediction accuracy of UPV was significantly high (R2=0.889) but the prediction accuracy of fc and fr was low (R2fc=0.612 and R2ff=0.334).

Classifying the severity of pedestrian accidents using ensemble machine learning algorithms: A case study of Daejeon City (앙상블 학습기법을 활용한 보행자 교통사고 심각도 분류: 대전시 사례를 중심으로)

  • Kang, Heungsik;Noh, Myounggyu
    • Journal of Digital Convergence
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    • v.20 no.5
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    • pp.39-46
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    • 2022
  • As the link between traffic accidents and social and economic losses has been confirmed, there is a growing interest in developing safety policies based on crash data and a need for countermeasures to reduce severe crash outcomes such as severe injuries and fatalities. In this study, we select Daejeon city where the relative proportion of fatal crashes is high, as a case study region and focus on the severity of pedestrian crashes. After a series of data manipulation process, we run machine learning algorithms for the optimal model selection and variable identification. Of nine algorithms applied, AdaBoost and Random Forest (ensemble based ones) outperform others in terms of performance metrics. Based on the results, we identify major influential factors (i.e., the age of pedestrian as 70s or 20s, pedestrian crossing) on pedestrian crashes in Daejeon, and suggest them as measures for reducing severe outcomes.

Performance Evaluation of ResNet-based Pneumonia Detection Model with the Small Number of Layers Using Chest X-ray Images (흉부 X선 영상을 이용한 작은 층수 ResNet 기반 폐렴 진단 모델의 성능 평가)

  • Youngeun Choi;Seungwan Lee
    • Journal of radiological science and technology
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    • v.46 no.4
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    • pp.277-285
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    • 2023
  • In this study, pneumonia identification networks with the small number of layers were constructed by using chest X-ray images. The networks had similar trainable-parameters, and the performance of the trained models was quantitatively evaluated with the modification of the network architectures. A total of 6 networks were constructed: convolutional neural network (CNN), VGGNet, GoogleNet, residual network with identity blocks, ResNet with bottleneck blocks and ResNet with identity and bottleneck blocks. Trainable parameters for the 6 networks were set in a range of 273,921-294,817 by adjusting the output channels of convolution layers. The network training was implemented with binary cross entropy (BCE) loss function, sigmoid activation function, adaptive moment estimation (Adam) optimizer and 100 epochs. The performance of the trained models was evaluated in terms of training time, accuracy, precision, recall, specificity and F1-score. The results showed that the trained models with the small number of layers precisely detect pneumonia from chest X-ray images. In particular, the overall quantitative performance of the trained models based on the ResNets was above 0.9, and the performance levels were similar or superior to those based on the CNN, VGGNet and GoogleNet. Also, the residual blocks affected the performance of the trained models based on the ResNets. Therefore, in this study, we demonstrated that the object detection networks with the small number of layers are suitable for detecting pneumonia using chest X-ray images. And, the trained models based on the ResNets can be optimized by applying appropriate residual-blocks.

A Qualitative Study on the Experience of Emotion Focused Psychology Coaching (정서중심심리코칭 경험에 관한 질적연구)

  • Kim, Hyun Jin;Jeong, Hyun-sub;Na, Eun Hye;Shin, Jin Young
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.3
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    • pp.203-212
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    • 2022
  • The purpose of this study is to investigate the nature of the experience of Emotion Focused Psychology Coaching, and what kind of changes happened for the participants through the experience. For this, in-depth interviews were conducted with four participants who had experienced five sessions of Emotion Focused Psychology Coaching. The interviews were analyzed using the phenomenological analysis method of Colaizzi. Emotion Focused Psychology Coaching is a new coaching psychology model that combines Greenberg's Emotion-Focused Therapy (EFT) and the ICF Core Competencies. The findings show that prior to the experience of Emotion Focused Psychology Coaching, the participants had avoided or suppressed their emotions, which in turn prevented them from exploring effective interpersonal relationships or alternatives in their actions. On the other hand, after they experienced Emotion Focused Psychology Coaching, their perception of emotions, emotion regulation, emotional expression, empathy for the other, etc. were developed in adaptive ways and the participants could present effective alternatives.

Soft computing based mathematical models for improved prediction of rock brittleness index

  • Abiodun I. Lawal;Minju Kim;Sangki Kwon
    • Geomechanics and Engineering
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    • v.33 no.3
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    • pp.279-289
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    • 2023
  • Brittleness index (BI) is an important property of rocks because it is a good index to predict rockburst. Due to its importance, several empirical and soft computing (SC) models have been proposed in the literature based on the punch penetration test (PPT) results. These models are very important as there is no clear-cut experimental means for measuring BI asides the PPT which is very costly and time consuming to perform. This study used a novel Multivariate Adaptive regression spline (MARS), M5P, and white-box ANN to predict the BI of rocks using the available data in the literature for an improved BI prediction. The rock density, uniaxial compressive strength (σc) and tensile strength (σt) were used as the input parameters into the models while the BI was the targeted output. The models were implemented in the MATLAB software. The results of the proposed models were compared with those from existing multilinear regression, linear and nonlinear particle swarm optimization (PSO) and genetic algorithm (GA) based models using similar datasets. The coefficient of determination (R2), adjusted R2 (Adj R2), root-mean squared error (RMSE) and mean absolute percentage error (MAPE) were the indices used for the comparison. The outcomes of the comparison revealed that the proposed ANN and MARS models performed better than the other models with R2 and Adj R2 values above 0.9 and least error values while the M5P gave similar performance to those of the existing models. Weight partitioning method was also used to examine the percentage contribution of model predictors to the predicted BI and tensile strength was found to have the highest influence on the predicted BI.