• Journal of Information Processing Systems
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• v.19 no.3
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• pp.323-333
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• 2023

Facial expression recognition can aid in the development of fatigue driving detection, teaching quality evaluation, and other fields. In this study, a facial expression recognition method was proposed with a residual masking reconstruction network as its backbone to achieve more efficient expression recognition and classification. The residual layer was used to acquire and capture the information features of the input image, and the masking layer was used for the weight coefficients corresponding to different information features to achieve accurate and effective image analysis for images of different sizes. To further improve the performance of expression analysis, the loss function of the model is optimized from two aspects, feature dimension and data dimension, to enhance the accurate mapping relationship between facial features and emotional labels. The simulation results show that the ROC of the proposed method was maintained above 0.9995, which can accurately distinguish different expressions. The precision was 75.98%, indicating excellent performance of the facial expression recognition model.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.540-543
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• 2020

기존의 초해상도 딥러닝 기법은 모델의 깊이가 깊어지면서, 좋은 성능을 내지만 점점 더 복잡해지고 있고, 실제로 사용하는데 있어 많은 시간을 요구한다. 이를 해결하기 위해, 우리는 딥러닝 모델의 가중치를 양자화 하여 추론시간을 줄이고자 한다. 초해상도 모델은 feature extraction, non-linear mapping, reconstruction 세 부분으로 나누어져 있으며, 레이어 사이에 많은 skip-connection 이 존재하는 특징이 있다. 따라서 양자화 시 최종 성능 하락에 미치는 영향력이 레이어 별로 다르며, 이를 감안하여 강화학습으로 레이어 별 최적 bit 를 찾아 성능 하락을 최소화한다. 본 논문에서는 Skip-connection 이 많이 존재하는 MSRN 을 사용하였으며, 결과에서 feature extraction, reconstruction 부분과 블록 내 특정 위치의 레이어가 항상 높은 bit 를 가짐을 알 수 있다. 기존에 영상 분류에 한정되어 사용되었던 혼합 bit 양자화를 사용하여 초해상도 딥러닝 기법의 모델 사이즈를 줄인 최초의 논문이며, 제안 방법은 모바일 등 제한된 환경에 적용 가능할 것으로 생각된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.36-41
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• 2017

The mobile mapping system first introduced at Ohio State University in 1991 is being developed in various forms as sensor technology develops. The mobile mapping system can acquire geospatial information around amoving object quickly using the information gathered using the position and attitude information of the moving object and the data from various sensors. The mobile mapping system can rapidly acquire large amounts of Geospatial information and MMS provides maximum productivity in the same measurement methods as existing GNSS and total stations. Currently, a variety of systems are being launched, mainly by foreign companies, and they are applied to the construction of geospatial information. On the other hand, the application of domestic technology development or production is insufficient. This paper provides basic data for the introduction of a mobile mapping system to geospatial information related business by conducting the status survey and feature analysis of a commercialized system focusing on the ground-based mobile mapping system. The research identified the current status and characteristics of high-priced, low-priced, indoor, and handheld mobile mapping systems based on vehicles and suggest that the recent system development trends are moving toward lowering the unit prices. The mobile mapping system is currently being developed as a platform for the application of geospatial information construction and the launch of low-cost models. The development of data processing technologies, such as automatic matching and the launch of low-cost models, are forming a basis for the application of mobile mapping systems in the field of geospatial information construction.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.761-764
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• 1998

본 논문에서는 CCCD 카메라로부터 획득한 영상시퀀스들에서 인접한 두 영상 사이의 차영상과 얼굴이 가지는 컬러정보를 이용하여 분리한 얼굴 영역에서 양쪽 눈과 입의 위치좌표를 특징점으로 이용하여 입력된 얼굴에 자동정합된 변형가능 템플리트(deformable template)를 가지고 연속된 다음 프레임에서 얼굴 전체를 트래킹하는 알고리듬을 제안한다. 실제 입력영상의 얼굴 영역과 변형 가능 템플리트의 차이를 비교하기 위해 텍스쳐 매핑(Texture mapping)을 도입하여 트래킹의 정확도를 살펴본다.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.1169-1174
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• 1991

In conventional geographic mapping system, it is needed to input many already existing geographic map into computer system for secure and efficient maintence. Because of large map data, it is required to construct layers from map image for easy display, fast retreval and efficient storage. Thus this paper represents a method of the extracting features from contour map and constructing three layers. The layers are symbol, building, contour line. Experimental results are presented confirming the method's high extraction.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.320-324
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• 2003

The Andong batholith is a Jurassic plutonic complex intruding metamorphic rocks of the RRyeongnam massif that extends from NE to SW in the southern Korean Peninsula. Detailed mapping and petrographic studies show that the batholith exhibits five sparate plutons: Andong, Dosan, Pungsan, Imha, and Nokjeon. The oldest Andong pluton among them exhibits reverse zoning. This feature contrasts with typical modal and chemical zoning trends in calc-alkaline plutons in which higher color index and more mafic rocks in the outer rim surround lower color index felsic rocks in the interior. (omitted)

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.263-265
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• 2020

본 논문에서는 다중 스케일로 구성된 뉴럴 네트워크를 이용하여 영상 내 모아레 무늬을 제거하는 기법을 제안한다. 제안하는 기법은 영상 피라미드를 생성하여 모아레 무늬를 구성하는 다양한 주파수 범위의 정보를 제거한다. 각 branch는 Multi-scale Feature Block (MFB)과 Tone-Mapping Block (TMB)으로 구성하여 효과적으로 모아레 현상을 제거하고 저하된 색상 저하를 복원한다. 컴퓨터 모의실험을 통해 제안하는 기법이 기존 기법에 비해서 높은 모아레 제거 성능을 보이는 것을 확인한다.

• Korean Journal of Radiology
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• v.22 no.6
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• pp.880-889
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• 2021

Objective: This study aimed to investigate the regional amyloid burden and myocardial deformation using T1 mapping and strain values in patients with cardiac amyloidosis (CA) according to late gadolinium enhancement (LGE) patterns. Materials and Methods: Forty patients with CA were divided into 2 groups per LGE pattern, and 15 healthy subjects were enrolled. Global and regional native T1 and T2 mapping, extracellular volume (ECV), and cardiac magnetic resonance (CMR)-feature tracking strain values were compared in an intergroup and interregional manner. Results: Of the patients with CA, 32 had diffuse global LGE (group 2), and 8 had focal patchy or no LGE (group 1). Global native T1, T2, and ECV were significantly higher in groups 1 and 2 than in the control group (native T1: 1384.4 ms vs. 1466.8 ms vs. 1230.5 ms; T2: 53.8 ms vs. 54.2 ms vs. 48.9 ms; and ECV: 36.9% vs. 51.4% vs. 26.0%, respectively; all, p < 0.001). Basal ECV (53.7%) was significantly higher than the mid and apical ECVs (50.1% and 50.0%, respectively; p < 0.001) in group 2. Basal and mid peak radial strains (PRSs) and peak circumferential strains (PCSs) were significantly lower than the apical PRS and PCS, respectively (PRS, 15.6% vs. 16.7% vs. 26.9%; and PCS, -9.7% vs. -10.9% vs. -15.0%; all, p < 0.001). Basal ECV and basal strain (2-dimensional PRS) in group 2 showed a significant negative correlation (r = -0.623, p < 0.001). Group 1 showed no regional ECV differences (basal, 37.0%; mid, 35.9%; and apical, 38.3%; p = 0.184). Conclusion: Quantitative T1 mapping parameters such as native T1 and ECV may help diagnose early CA. ECV, in particular, can reflect regional differences in the amyloid deposition in patients with advanced CA, and increased basal ECV is related to decreased basal strain. Therefore, quantitative CMR parameters may help diagnose CA and determine its severity in patients with or without LGE.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.11
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• pp.1098-1102
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• 2014

Localization of aerial vehicles and map building of flight environments are key technologies for the autonomous flight of small UAVs. In outdoor environments, an unmanned aircraft can easily use a GPS (Global Positioning System) for its localization with acceptable accuracy. However, as the GPS is not available for use in indoor environments, the development of a SLAM (Simultaneous Localization and Mapping) system that is suitable for small UAVs is therefore needed. In this paper, we suggest a vision-based SLAM system that uses vision sensors and an AHRS (Attitude Heading Reference System) sensor. Feature points in images captured from the vision sensor are obtained by using GPU (Graphics Process Unit) based SIFT (Scale-invariant Feature Transform) algorithm. Those feature points are then combined with attitude information obtained from the AHRS to estimate the position of the small UAV. Based on the location information and color distribution, a Gaussian process model is generated, which could be a map. The experimental results show that the position of a small unmanned aircraft is estimated properly and the map of the environment is constructed by using the proposed method. Finally, the reliability of the proposed method is verified by comparing the difference between the estimated values and the actual values.

• The Journal of the Acoustical Society of Korea
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• v.22 no.3
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• pp.182-187
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• 2003

In this thesis, we propose the algorithm to improve the performance of speaker verification that is mapping feature parameters by using RBF neural network. There is a big difference between wire vector region and wireless one which comes from the same speaker. For wire/wireless speakers model production, speaker verification system should distinguish the wire/wireless channel that based on speech recognition system. And the feature vector of untrained channel models is mapped to the feature vector(LPC Cepstrum) of trained channel model by using RBF neural network. As a simulation result, the proposed algorithm makes 0.6%∼10.5% performance improvement compared to conventional method such as cepstral mean subtraction.