• 조명전기설비학회논문지
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• 제19권1호
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• pp.9-14
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• 2005

Fabry-Perot 레이저 다이오드의 missing mode의 원인으로 의심되는 활성층 내의 구조적 결함과 리플의 영향을 TDLM(time domain laser model)방식을 사용하여 모델링하였다. 보다 정확한 모델링의 결과를 얻기 위하여 여러가지 비선형 효과를 추가 고려하였다. 이를 이용하여 레이저 다이오드를 시뮬레이션하였고, 모드 스펙트럼(mode spectrum)을 구하였다. 실제 레이저 다이오드의 missing mode를 측정하기 위한 실험 장비를 구성하여 측정 결과를 추출하였고, 시뮬레이션과 측정 실험 결과로부터 결론을 내렸다.

• International Journal of Contents
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• 제12권3호
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• pp.22-28
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• 2016

Tensor with missing or incomplete values is a ubiquitous problem in various fields such as biomedical signal processing, image processing, and social network analysis. In this paper, we considered how to reconstruct a dataset with missing values by using tensor form which is called tensor completion process. We applied Tucker factorization to solve tensor completion which was built base on optimization problem. We formulated the optimization objective function using components of Tucker model after decomposing. The weighted least square matric contained only known values of the tensor with low rank in its modes. A first order optimization method, namely Nonlinear Conjugated Gradient, was applied to solve the optimization problem. We demonstrated the effectiveness of the proposed method in EEG signals with about 70% missing entries compared to other algorithms. The relative error was proposed to compare the difference between original tensor and the process output.

• 한국지구과학회지
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• 제38권6호
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• pp.427-441
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• 2017

Theory of Earth's free oscillation is revisited. Firstly, we summarized the underlying formulations, such as the equation of motion and its conversion into numerically integrable form and then explained computational procedures including the treatment of inner core-outer core boundary and core-mantle boundary, while the latter information has not been explicitly given in most publications. Secondly, we re-calculated the periods of Earth's free oscillation modes (period >200 s) for PREM model. In doing so we acquired the values of modes missing in Dziewonski and Anderson (1981). As a case observation, one seismogram after 2011 Tohoku earthquake recorded at Daejeon, Korea (KIGAM seismic station) was briefly analyzed to identify free oscillation mode excitations on its spectra. The material in this article will be most clear guide for those on calculating the Earth's free oscillation mode.

• Smart Structures and Systems
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• 제17권5호
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• pp.795-817
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• 2016

A non-contact, in-situ and non-invasive technique for health monitoring of submerged fiber reinforced polymers (FRP) laminates has been developed using ultrasonic guided waves. A pair of mobile transducers at specific angles of incidence to the submerged FRP specimen was used to excite Lamb wave modes. Lamb wave modes were used for comprehensive inspection of various types of manufacturing defects like air gaps and missing epoxy, introduced during manufacturing of FRP using Vacuum Assisted Resin Infusion Molding (VARIM). Further service induced damages like notches and surface defects were also studied and evaluated using guided waves. Quantitative evaluation of transmitted ultrasonic signal in defect ridden FRPs $vis-{\grave{a}}-vis$ healthy signal has been used to relate the extent of damage in FRPs. The developed technique has the potential to develop into a quick, real time health monitoring tool for judging the service worthiness of FRPs.

• Earthquakes and Structures
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• 제2권4호
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• pp.323-336
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• 2011

The problem of reconstruction of complete building response from a limited number of response measurements is considered. The response at the intermediate degrees of freedom is reconstructed by using piecewise cubic Hermite polynomial interpolation in time domain. The piecewise cubic Hermite polynomial interpolation is preferred over the spline interpolation due to its trend preserving character. It has been shown that factorization of response data in variable separable form via singular value decomposition can be used to derive the complete set of normal modes of the structural system. The time domain principal components can be used to derive empirical transfer functions from which the natural frequencies of the structural system can be identified by peak-picking technique. A reduced-rank approximation for the system flexibility matrix can be readily constructed from the identified mass-orthonormal mode shapes and natural frequencies.

• 응용통계연구
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• 제28권2호
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• pp.159-174
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• 2015

최근에 Dragomiretskiy와 Zosso (2014)는 경험적모드분해의 단점을 보완하여 새로운 신호 분해방법인 변동모드분해법(Variational Mode Decomposition)을 고안하였다. 기본적으로 변동모드분해법은 경험적모드분해법에 비하여 주파수 탐색 및 분리(tone detection and tone separation)에 탁월한 성능을 보인다. 또한 고속퓨리에변환을 기반으로 한 알고리즘을 사용하여 경험적모드분해법보다 잡음에 강건하다는 장점이 있다. 하지만 변동모드분해법은 결측 등으로 신호가 동일한 시간간격 혹은 공간적 간격으로 측정되지 않은 경우 제대로 동작하지 않는 단점이 있다. 이를 보완하기 위해서 본 논문에서는 변동모드분해법에 다단계우도함수를 조합하는 새로운 방법을 제안한다. 여기에서 다단계우도함수는 변동모드분해법이 신호를 적절한 내재모드함수로 분해하기 전에 결측치를 대체하는 효율적인 방법을 제시한다. 모의실험과 실제 자료의 사례연구를 통하여 변동모드분해법이 기존의 방법보다 더 효율적으로 신호를 분해한다는 것을 보일 것이다.

• 대한장애인치과학회지
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• 제3권1호
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• pp.1-5
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• 2007

Patients of mental disorder have more missing teeth than general population because of the difficulty of oral hygiene management. In addition, especially Down syndrome patients etc., congenital dental problems develop more frequently. Therefore, prosthetic rehabilitation treatments for missing teeth in mental disorder patients are required more urgently. In other words, a removable partial denture may be very difficult for such patients to wear and manage. So in this review article we reviewed implant therapeutic modes for mental disorder patients based on previous reports. It should be understood that implant treatments are not impossible for mental disorder patients, and if implants could be a good method that could provide them good quality care, so implant should be included in treatment plans before surgery. Before surgery it should be evaluated that patients ability to manage themselves their ability to manage themselves should be evaluated and also should be evaluated whether general anesthesia or sedative treatment is required for the treatment, and whether their cooperation is good enough.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권8호
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• pp.2473-2489
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• 2022

Urban development has brought about the increasing saturation of urban traffic demand, and traffic congestion has become the primary problem in transportation. Roads are in a state of waiting in line or even congestion, which seriously affects people's enthusiasm and efficiency of travel. This paper mainly studies the discrete domain path planning method based on the flow data. Taking the traffic flow data based on the highway network structure as the research object, this paper uses the deep learning theory technology to complete the path weight determination process, optimizes the path planning algorithm, realizes the vehicle path planning application for the expressway, and carries on the deployment operation in the highway company. The path topology is constructed to transform the actual road information into abstract space that the machine can understand. An appropriate data structure is used for storage, and a path topology based on the modeling background of expressway is constructed to realize the mutual mapping between the two. Experiments show that the proposed method can further reduce the interpolation error, and the interpolation error in the case of random missing is smaller than that in the other two missing modes. In order to improve the real-time performance of vehicle path planning, the association features are selected, the path weights are calculated comprehensively, and the traditional path planning algorithm structure is optimized. It is of great significance for the sustainable development of cities.

• Journal of Information Processing Systems
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• 제17권4호
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• pp.754-771
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• 2021

In the task of continuous dimension emotion recognition, the parts that highlight the emotional expression are not the same in each mode, and the influences of different modes on the emotional state is also different. Therefore, this paper studies the fusion of the two most important modes in emotional recognition (voice and visual expression), and proposes a two-mode dual-modal emotion recognition method combined with the attention mechanism of the improved AlexNet network. After a simple preprocessing of the audio signal and the video signal, respectively, the first step is to use the prior knowledge to realize the extraction of audio characteristics. Then, facial expression features are extracted by the improved AlexNet network. Finally, the multimodal attention mechanism is used to fuse facial expression features and audio features, and the improved loss function is used to optimize the modal missing problem, so as to improve the robustness of the model and the performance of emotion recognition. The experimental results show that the concordance coefficient of the proposed model in the two dimensions of arousal and valence (concordance correlation coefficient) were 0.729 and 0.718, respectively, which are superior to several comparative algorithms.

• 한국군사과학기술학회지
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• 제15권1호
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• pp.9-15
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• 2012

This paper shows an effective scanning trajectory for a mine detection device that is one of the mission equipments of unmanned ground vehicle. The mine detection device is composed of a mine-detection sensor, and a 4 DOF manipulator enabling sensor position control. There are three modes that manage the mine detection device: passive, semi-automatic, and automatic. The automatic mode is used the most. This paper suggests a scanning method that makes shape of 8. This method prevents missing target area and enhances scanning speed when the mine detection device scans the ground surface in automatic mode. The suggested method is verified by simulations and experiments.