• 산업경영시스템학회지
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• 제45권2호
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• pp.12-19
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• 2022

Artificial intelligence is driving the Fourth Industrial Revolution and is in the spotlight as a general-purpose technology. As the data collection from the battlefield increases rapidly, the need to us artificial intelligence is increasing in the military, but it is still in its early stages. In order to identify maritime targets, Republic of Korea navy acquires images by ISAR(Inverse Synthetic Aperture Radar) of maritime patrol aircraft, and humans make out them. The radar image is displayed by synthesizing signals reflected from the target after radiating radar waves. In addition, day/night and all-weather observations are possible. In this study, an artificial intelligence is used to identify maritime targets based on radar images. Data of radar images of 24 maritime targets in Republic of Korea and North Korea acquired by ISAR were pre-processed, and an artificial intelligence algorithm(ResNet-50) was applied. The accuracy of maritime targets identification showed about 99%. Out of the 81 warship types, 75 types took less than 5 seconds, and 6 types took 15 to 163 seconds.

• 한국전자파학회논문지
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• 제29권1호
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• pp.68-76
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• 2018

표적 우선순위 할당은 다수의 표적이 존재하는 전술 환경에서 다기능 레이다(Multifunction Radar: MFR)가 중요한 표적을 추적하고 레이다 자원을 효율적으로 관리하기 위해 필요한 기능이다. 본 논문에서는 레이다에서 수집한 정보로부터 표적에 대한 우선순위를 산출하는 인공 신경망(Artificial Neural Network: ANN) 모델을 구현한다. 더 나아가, 기존의 경사 하강법(gradient descent) 기반 역전파(backpropagation) 알고리즘을 발전시켜 표적 우선순위 할당에 더욱 적합한 최급 강하법(steepest descent) 기반 신경망 학습 알고리즘을 제안한다. 시뮬레이션에서는 훈련 데이터와 신경망의 결과값 사이의 오차와 특정 테스트 시나리오에서 할당된 우선순위의 합리성을 분석하여 제안된 방법의 성능을 확인한다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.177-179
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• 2022

Google Deepmind Challenge match에서, Alphago가 바둑 대결에서 4승1패로 한국의 이세돌(인간)에 승리하였다. 드디어, 인공지능은 인간 지능의 활용을 넘어서고 있는 것이다. 한국 정부의 디지털뉴딜의 사업예산은 2022년 9조원이며, 인공지능 학습용 data 구축사업은 301종을 추가로 확보한다. 2023년부터는 산업의 전 분야에서 인공지능의 학습의 활용과 적용으로 산업 패러다임이 변화될 것이다. 본 논문은 인공지능 알고리즘을 활용하기 위한 연구를 한다. 인공지능 학습에서 data의 분석과 판단을 중심으로, 인공지능 머신러닝과 딥러닝 학습에서의 알고리즘의 적절한 활용 대상과 활용 범위에 대한 연구를 한다. 본 연구는 4차산업혁명기술의 인공지능과 5차산업혁명기술의 인공지능로봇 활용의 기초자료를 제공할 것이다.

• Smart Structures and Systems
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• 제32권1호
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• pp.49-59
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• 2023

A bridge transportation network supplies products from various source nodes to destination nodes through bridge structures in a target region. However, recent frequent earthquakes have caused damage to bridge structures, resulting in extreme direct damage to the target area as well as indirect damage to other lifeline structures. Therefore, in this study, a surrogate model-based comprehensive framework to estimate the seismic resilience of bridge transportation networks is proposed. For this purpose, total system travel time (TSTT) is introduced for accurate performance indicator of the bridge transportation network, and an artificial neural network (ANN)-based surrogate model is constructed to reduce traffic analysis time for high-dimensional TSTT computation. The proposed framework includes procedures for constructing an ANN-based surrogate model to accelerate network performance computation, as well as conventional procedures such as direct Monte Carlo simulation (MCS) calculation and bridge restoration calculation. To demonstrate the proposed framework, Pohang bridge transportation network is reconstructed based on geographic information system (GIS) data, and an ANN model is constructed with the damage states of the transportation network and TSTT using the representative earthquake epicenter in the target area. For obtaining the seismic resilience curve of the Pohang region, five epicenters are considered, with earthquake magnitudes 6.0 to 8.0, and the direct and indirect damages of the bridge transportation network are evaluated. Thus, it is concluded that the proposed surrogate model-based framework can efficiently evaluate the seismic resilience of a high-dimensional bridge transportation network, and also it can be used for decision-making to minimize damage.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.61-68
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• 1999

In the nonlinear dynamic structural analysis the given ground excitation as an input should be well defined. Because of the lack of recorded accelerograms in Korea it is required to generate an artificial earthquake by a stochastic model of ground excitation with various dynamic properties rather than recorded accelerograms. It is well known that earthquake motions are generally non-stationary with time-varying intensity and frequency content. Many researchers have proposed non-stationary random process models. Yeh and Wen (1990) proposed a non-stationary modulation function and a power spectral density function to describe such non-stationary characteristics. Satio and Wen(1994) proposed a non-stationary stochastic process model to generate earthquake ground motions which are compatible with design reponse spectrum at sites in Japan. this paper shows the process to modify power spectrum compatible with target design response spectrum for generating of nonstationary artificial earthquake ground motions. Target reponse spectrum is chosen by ATC14 to calibrate the response spectrum according to a give recurrence period.

• International journal of advanced smart convergence
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• 제10권3호
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• pp.122-130
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• 2021

This study is about an Artificial Intelligence-based fake news identification system and its methods to determine the authenticity of content distributed over the Internet. Among the news we encounter is news that an individual or organization intentionally writes something that is not true to achieve a particular purpose, so-called fake news. In this study, we intend to design a system that uses Artificial Intelligence techniques to identify fake content that exists within the news. The proposed identification model will propose a method of extracting multiple unit factors from the target content. Through this, attempts will be made to classify unit factors into different types. In addition, the design of the preprocessing process will be carried out to parse only the necessary information by analyzing the unit factor. Based on these results, we will design the part where the unit fact is analyzed using the deep learning prediction model as a predetermined unit. The model will also include a design for a database that determines the degree of fake news in the target content and stores the information in the identified unit factor through the analyzed unit factor.

• 한국콘텐츠학회논문지
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• 제20권11호
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• pp.292-300
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• 2020

인공지능 기술이 발전함에 따라 경제, 사회, 과학 분야 등 실세계 다양한 분야의 현상을 가상의 인공 에이전트를 활용한 컴퓨터 시뮬레이션을 통해 해석하려는 시도가 이어져 왔다. 기존의 인공 에이전트 기반 교섭 게임 해석에서는 실세계의 교섭 게임에서 단계가 진행될 때 발생하는 비용 및 시간이 지남에 따라 교섭 대상이 감가상각 되는 것을 반영하지 않은 문제가 있었다. 본 연구에서는 기존의 인공 에이전트 기반 교섭 게임 모델에 교섭 단계에서 발생하는 비용 및 교섭 대상 감가상각을 (교섭 비용)을 반영하여 그 효과를 관찰하였다. 실험 결과 교섭 단계에서 발생하는 비용이 커질수록 게임에 참여하는 두 인공 에이전트는 반반 비율에 가까운 몫을 가졌으며 이른 단계에서 협상을 타결하는 현상을 관찰하였다.

• Ocean Systems Engineering
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• 제4권1호
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• pp.53-62
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• 2014

The detection of ship wakes image can demonstrate substantial information regarding on a ship, such as its tonnage, type, direction, and speed of movement. Consequently, the wake target recognition is a favorable way for ship identification. This paper proposes a Local Binary Pattern (LBP) approach to extract image features (wakes) for training an Improved Back Propagation Artificial Neural Network (IBPANN) to identify ship speed. This method is applied to sort and recognize the ship wakes of five different speeds images, the result shows that the detection accuracy is satisfied as expected, the average correctness rates of wakes target recognition at the five speeds may be achieved over 80%. Specifically, the lower ship's speed, the better accurate rate, sometimes it's accuracy could be close to 100%. In addition, one significant feature of this method is that it can receive a higher recognition rate than the nearest neighbor classification method.

• Structural Engineering and Mechanics
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• 제26권6호
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• pp.709-723
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• 2007

Considering the vast usage of time-history dynamic analyses to calculate structural responses and lack of sufficient and suitable earthquake records, generation of artificial accelerograms is very necessary. The main target of this paper is to present a novel method based on nonstationary Kanai-Tajimi model and wavelet transform to generate more artificial earthquake records, which are compatible with target spectrum. In this regard, the generalized nonstationary Kanai-Tajimi model to include the nonstationary evaluation of amplitude and dominant frequency of ground motion and properties of wavelet transform is used to generate ground acceleration time history. Application of the method for El Centro 1940 earthquake and two Iranian earthquakes (Tabas 1978 and Manjil 1990) is presented. It is shown that the model and identification algorithms are able to accurately capture the nonstationary features of these earthquake accelerograms. The statistical characteristics of the spectral response of the generated accelerograms are compared with those for the actual records to demonstrate the effectiveness of the method. Also, for comparison of the presented method with other methods, the response spectra of the synthetic accelerograms compared with the models of Fan and Ahmadi (1990) and Rofooei et al. (2001) and it is shown that the response spectra of the synthetic accelerograms with the method of this paper are close to those of actual earthquakes.

• 한국건축시공학회지
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• 제22권3호
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• pp.317-326
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• 2022

건설 분야에서 머신러닝(Machine learning)에 필요한 방대한 공사비 자료를 확보하는 데 어려움이 있어, 아직은 실용적으로 활용되지는 못하고 있다. 본 연구에서는 이러한 공사비 예측을 위하여 최신의 인공신경망(ANN) 방법을 사용하여, 공사비 예측성능을 향상 시키기 위한 방법을 제시하고자 한다. 특히 타겟변수를 로그 변환하는 방식, 피처스케일링 방식을 적용하고자 하였으며, 이들의 공사비 예측성능을 비교 분석하고자 한다. 이는 향후 다양한 조건을 갖는 공사비 예측과 적정 공사비 검증에 도움을 줄 수 있을 것으로 예측된다.