• 한국융합학회논문지
• /
• 제11권12호
• /
• pp.15-22
• /
• 2020

본 논문은 채널 강조(Channel Attentin)와 공간 강조(Spatial Attention) 방법을 결합한 딥 러닝 기반의 초해상도 방법을 제안하였다. 초해상도 과정에서 질감, 특징과 같은 주변 픽셀의 변화량이 큰 고주파 성분의 복원이 중요하다. 채널 강조와 공간 강조를 결합한 특징 강조를 이용한 초해상도 방법을 제안하였다. 기존의 CNN(Convolutional Neural Network) 기반의 초해상도 방법은 깊은 네트워크의 학습이 어려우며, 고주파 성분의 강조가 부족하여 윤곽선이 흐려지거나 왜곡이 발생한다. 문제를 해결하기 위해 스킵-커넥션(Skip Connection)을 적용한 채널 강조와 공간 강조를 결합한 강조 블록과 잔차 블록(Residual Block)을 사용하였다. 방법으로 추출한 강조된 특징 맵을 부-픽셀 컨볼루션(Sub-pixel Convolution)을 통해 특징맵을 확장하여 초해상도를 진행하였다. 이를 통해 기존의 SRCNN과 비교하여 약 PSNR는 5%, SSIM은 3% 향상되었으며 VDSR과 비교를 통해 약 PSNR는 2%, SSIM은 1% 향상된 결과를 보였다.

• 사물인터넷융복합논문지
• /
• 제8권2호
• /
• pp.79-84
• /
• 2022

본 논문은 문서의 보안과 손실 및 오염에 대하여 복원능력을 향상시키는 방안을 제안한다. 이를 위해서 암호화로 DnCNN(DeNoise Convolution Neural Network)을 제시한다. 암호화 방법을 구현하기 위하여 2D이미지정보를 광학에 사용되는 공간주파수 전달함수(Spatial Frequency Transfer Function)의 수학적 모델을 적용한다. 공간 주파수 전달함수를 사용하여 광학적 간섭 패턴을 암호화로 사용하고 공간 주파수 전달함수의 수학적 변수를 복호화하는 암호로 사용하는 방법을 제안하였다. 또한, 딥러닝을 적용한 DnCNN 방법을 적용하여 노이즈 제거하여 복원 성능을 개선한다. 실험결과, 65%의 정보 손실이 있는 경우에도 Pre-Training DnCNN Deep Learning을 적용한 결과 공간 주파수 전달함수만을 활용한 복원 결과 와 비교하여 PSNR(Peak Signal-to-noise ratio)을 11% 이상 우수한 성능을 확인할 수 있다. 또한, CC(Correlation Coefficient)의 특성도 16% 이상 우수한 결과를 보이고 있다.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2017년도 추계학술대회
• /
• pp.313-315
• /
• 2017

최근 머신 러닝을 이용한 적용 분야가 광범위하게 확대되고 있다. 또한 스마트 기기의 보급과 더불어 위치 기반 서비스를 이용한 응용 서비스 역시 다양하게 요구되고 있다. 그러나 측위를 위한 정보를 수집할 수 없는 재난 상황과 실내용 위치 측위 정보를 사용할 수 없는 특정 공간과 같은 실내 환경에서는 측위를 통한 응용 서비스의 제공이 어렵다. 이러한 상황에서 증강현실 환경에 등록된 주변의 마커 정보와 마커들이 구성된 공간 정보를 이용하면 특정 상황 또는 위치에서의 측위 및 응용 서비스의 제공이 가능하게 된다. 이때 마커 기반 공간 정보의 구성과 실제 위치가 대응되도록 하는 연산을 머신 러닝을 통해 학습하고 오차를 최소화하면 최적의 측위 결과를 얻을 수 있다. 본 논문은 증강현실의 마커들과 공간 정보의 학습을 위해 머신 러닝을 이용하여 특정 상황에서 요구되는 측위 방법에 대해 연구하였다.

• 한국수학교육학회지시리즈D:수학교육연구
• /
• 제16권2호
• /
• pp.91-106
• /
• 2012

Spatial ability has been valued as a talent domain and important skill in mathematics education because it enhanced an intuitive view and an understanding in many areas of mathematic. In addition, spatial ability highly correlates with mathematics achievement, indicating its crucial role in success in mathematics education. Some researchers founded gender differences in mathematics and spatial ability, and indicated that spatial ability served as a mediator of gender difference in mathematics. This study explored the spatial ability of 349 Korean middle school students (Grade 7-9), and investigated the association among students' spatial ability and their mathematics achievement, gender, and grade. The result of this study shows that spatial ability correlates positively with mathematics achievement. While gender difference did not exist in mathematics, significant gender difference existed in spatial ability favoring male students.

• 동의생리병리학회지
• /
• 제20권2호
• /
• pp.471-476
• /
• 2006

Chongmyung-tang(CMT, 聰明湯), oriental herbal medicine which consists of Polygaglae Radix(遠志), Acori Graminei Rhizoma(石菖蒲) and Hoelen(白茯神) has effect on amnesia, dementia. In order to evaluate effect of CMT on memory and learning in mice, CMT extract was used for studies. This paper describes the effects of CMT extract on memory and learning processes by using the passive and active avoidance performance tests, novel object recognition task and water maze task. The CMT extract ameliorated the memory retrieval deficit induced by ethanol in the passive avoidance responses but did not affect ambulatory activity of normal mice. These results suggest that CMT has an ameliorating effect on memory retrieval impairment. CMT extract decreased spontaneous motor activity(SMA) in the latter sessions of memory registration in active avoidance responses. These results suggest that CMT has partly transquilizing or antianxiety effects. In novel object recognition task to measure visual recognition memory, CMT-administered mice enhanced in long term memory for 1-3 days. In water maze task to measure spatial learning, which requires the activation of NMDA receptors in the hippocampus, spatial learning in CMT-administered mice was faster than in wild-type mice. These results suggest that CMT enhances memory and activates NMDA receptors.

• 대한지구과학교육학회지
• /
• 제8권1호
• /
• pp.76-86
• /
• 2015

The purpose of this study is to take advantage of the smart teaching - learning programs about the unit of 'Earth and Moon' and find out how to apply the effect appears. Teaching-Learning program was conducted over eight lessons. And we analyzed the effect of the program at any time through the evaluation and interview. The results are as follows. First, this study proposed a method to assist in the teaching and learning of spatial ability for students' movement of the Earth and the Moon. The program takes advantage of N-Screen Applications were configured to allow both Earth observation insider perspective and the external multilateral perspective. This improves students' understanding qualitatively. Second, we applied the teaching and learning programs utilizing smart smart devices, and the result was a lot of low rank students' average score rises. In addition, we were able to see that many students' understanding and interest, self-confidence are improved.

• ETRI Journal
• /
• 제42권5호
• /
• pp.686-699
• /
• 2020

In this paper, we propose a supervised-learning-based spatial performance prediction (SLPP) framework for next-generation heterogeneous communication networks (HCNs). Adaptive asset placement, dynamic resource allocation, and load balancing are critical network functions in an HCN to ensure seamless network management and enhance service quality. Although many existing systems use measurement data to react to network performance changes, it is highly beneficial to perform accurate performance prediction for different systems to support various network functions. Recent advancements in complex statistical algorithms and computational efficiency have made machine-learning ubiquitous for accurate data-based prediction. A robust network performance prediction framework for optimizing performance and resource utilization through a linear discriminant analysis-based prediction approach has been proposed in this paper. Comparison results with different machine-learning techniques on real-world data demonstrate that SLPP provides superior accuracy and computational efficiency for both stationary and mobile user conditions.

• 한국공간구조학회논문집
• /
• 제18권4호
• /
• pp.69-80
• /
• 2018

In this study, an algorithm applying deep learning to the truss structures was proposed. Deep learning is a method of raising the accuracy of machine learning by creating a neural networks in a computer. Neural networks consist of input layers, hidden layers and output layers. Numerous studies have focused on the introduction of neural networks and performed under limited examples and conditions, but this study focused on two- and three-dimensional truss structures to prove the effectiveness of algorithms. and the training phase was divided into training model based on the dataset size and epochs. At these case, a specific data value was selected and the error rate was shown by comparing the actual data value with the predicted value, and the error rate decreases as the data set and the number of hidden layers increases. In consequence, it showed that it is possible to predict the result quickly and accurately without using a numerical analysis program when applying the deep learning technique to the field of structural analysis.

• 한국공간구조학회논문집
• /
• 제21권4호
• /
• pp.73-80
• /
• 2021

A mid-story isolation system was proposed for seismic response reduction of high-rise buildings and presented good control performance. Control performance of a mid-story isolation system was enhanced by introducing semi-active control devices into isolation systems. Seismic response reduction capacity of a semi-active mid-story isolation system mainly depends on effect of control algorithm. AI(Artificial Intelligence)-based control algorithm was developed for control of a semi-active mid-story isolation system in this study. For this research, an practical structure of Shiodome Sumitomo building in Japan which has a mid-story isolation system was used as an example structure. An MR (magnetorheological) damper was used to make a semi-active mid-story isolation system in example model. In numerical simulation, seismic response prediction model was generated by one of supervised learning model, i.e. an RNN (Recurrent Neural Network). Deep Q-network (DQN) out of reinforcement learning algorithms was employed to develop control algorithm The numerical simulation results presented that the DQN algorithm can effectively control a semi-active mid-story isolation system resulting in successful reduction of seismic responses.

• 한국공간구조학회논문집
• /
• 제22권2호
• /
• pp.39-46
• /
• 2022

Recently, machine learning is widely used to solve optimization problems in various engineering fields. In this study, machine learning is applied to development of a control algorithm for a smart control device for reduction of seismic responses. For this purpose, Deep Q-network (DQN) out of reinforcement learning algorithms was employed to develop control algorithm. A single degree of freedom (SDOF) structure with a smart tuned mass damper (TMD) was used as an example structure. A smart TMD system was composed of MR (magnetorheological) damper instead of passive damper. Reward design of reinforcement learning mainly affects the control performance of the smart TMD. Various hyper-parameters were investigated to optimize the control performance of DQN-based control algorithm. Usually, decrease of the time step for numerical simulation is desirable to increase the accuracy of simulation results. However, the numerical simulation results presented that decrease of the time step for reward calculation might decrease the control performance of DQN-based control algorithm. Therefore, a proper time step for reward calculation should be selected in a DQN training process.