• 한국분말재료학회지
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• 제24권4호
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• pp.285-291
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• 2017

We propose a custom analysis technique for the dark field (DF) image based on transmission electron microscopy (TEM). The custom analysis technique is developed based on the $DigitalMicrograph^{(R)}$ (DM) script language embedded in the Gatan digital microscopy software, which is used as the operational software for most TEM instruments. The developed software automatically scans an electron beam across a TEM sample and records a series of electron diffraction patterns. The recorded electron diffraction patterns provide DF and ADF images based on digital image processing. An experimental electron diffraction pattern is recorded from a IrMn polycrystal consisting of fine nanograins in order to test the proposed software. We demonstrate that the developed image processing technique well resolves nanograins of ~ 5 nm in diameter.

• 디지털콘텐츠학회 논문지
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• 제16권1호
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• pp.113-121
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• 2015

디지털 기술을 이용한 유물의 문양표현 방법은 크게 디지털 탁본기술과 디지털 명암기술의 두 가지가 있다. 디지털 탁본기술은 유물에 새겨진 명문이나 문양을 원형의 훼손 없이 3차원으로 스캐닝하고 이를 객관적 수치로 입체화시켜 명암효과를 표현함으로써 디지털 탁본 데이터를 구축하여 육안으로 확인하기 어려운 원래의 명문이나 문양을 명확하게 나타낼 수 있는 디지털 기술을 말한다. 디지털 명암기술은 유물 표면의 유리질 피막으로 인해서 대상물의 깊이정보를 계산할 수 없는 경우 3차원으로 스캐닝하고 이를 실감이미지 맵핑기술을 응용하여 디지털 명암이미지를 생성하는 디지털 기술을 말한다. 디지털 탁본기술은 주로 토기나 기와 그리고 비석 등 음각 또는 양각으로 표현된 명문이나 문양을 표현하는데 유용하며, 디지털 명암기술은 디지털 탁본기술이 적용될 수 없는 자기나 유리 등의 유물에 효과적으로 이용될 수 있다.

• Journal of Power Electronics
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• 제15권6호
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• pp.1517-1523
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• 2015

The wavelet PWM (WPWM) technique has been applied in two-level inverters successfully, but directly applying the WPWM technique to three-level inverters is impossible. This paper proposes a WPWM technique suitable for a single-phase three-level inverter. The work analyzes the control strategy with the WPWM and obtains the design of its parameters. Compared with the SPWM technique for a single-phase three-level inverter under the same conditions, the WPWM can obtain high magnitudes of the output fundamental frequency component, low total harmonic distortion, and simpler digital implementation. The feasibility experiment is given to verify of the proposed WPWM technique.

• Steel and Composite Structures
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• 제23권2호
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• pp.161-172
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• 2017

A new composite tube connection method called the pre-tightened teeth connection technique is proposed to improve the composite tube connection efficiency. This paper first introduces the manufacturing process of the proposed technique. It then outlines how the mechanical properties of this technology were tested using four test groups. The factors that influence the load-bearing capacity and damage model of the connection were analyzed, and finally, the transfer load mechanism was investigated. The following conclusions can be obtained from the research results. (1) The new technique improves the compressive connection efficiency by a maximum of 79%, with the efficiency exceeding that of adhesive connections of the same thickness. (2) Changing the depth of teeth results in two types of damage: local compressive damage and shear damage. The bearing capacity can be improved by increasing the depth, length, and number of teeth as well as the pre-tightening force. (3) The capacity of the technique to transfer high loads is a result of both the relatively high interlaminar shear strength of the pultruded composite and the interlaminar shear strength increase provided by the pre-tightening force. The proposed technique shows favorable mechanical properties, and therefore, it can be extensively applied in the engineering field.

• 대한치과기공학회지
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• 제25권1호
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• pp.103-109
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• 2003

The purpose of this study is to ensure natural restoration of gingiva's form by making effective use of materials in a bid to improve the technique of festooning for denture base. 1. The improved technique is expected to prevent the degradation and deformation of cavity structure and restore it. 2. The improved technique is expected to prevent the change of facial appearance from esthetic viewpoint and restore it. 3. The improved technique is expected to impress again the deformed part on wax denture for additional festooning.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권11호
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• pp.3658-3679
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• 2022

Classification of persons wearing and not wearing face masks in images has emerged as a new computer vision problem during the COVID-19 pandemic. In order to address this problem and scale up the research in this domain, in this paper a hybrid technique by employing ResNet-101 and multi-layer perceptron (MLP) classifier has been proposed. The proposed technique is tested and validated on a self-created face masks classification dataset and a standard dataset. On self-created dataset, the proposed technique achieved a classification accuracy of 97.3%. To embrace the proposed technique, six other state-of-the-art CNN feature extractors with six other classical machine learning classifiers have been tested and compared with the proposed technique. The proposed technique achieved better classification accuracy and 1-6% higher precision, recall, and F1 score as compared to other tested deep feature extractors and machine learning classifiers.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.951-956
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• 1990

The present paper describes a new technique for associating images employing a set of local constraints among pixels on an image. The technique describes the association problem in terms of consistent labeling which is an abstraction of various kinds of network constraints problems. In this particular research, a pixel and its gray value correspond to a unit and a label, respectively. Since constraints among units on an image are defined with respect to each n-tuple of pixels, performance of the present association technique largely depends on how to choose the n-tuples on an image plane. The main part of this paper is devoted to discussing this selection scheme and giving a solution to it as well as showing the algorithm of association. Also given are some results of the simulation performed on synthetic binary images to examine the performance of proposed technique, followed by the argument on further studies.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.727-730
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• 2002

This paper proposes the interference cancellation improvement in smart antenna system by using Applebaum array covariance matrix adjustment. This technique adds the specific adjustable multipliers with both desired signal covariance matrix and interference signal covariance matrices in order to overcome some disadvantages and improve the interference cancellation efficiency of Applebaum array. It is based on the desired and undesired signal power or desired signal-to-interference-plus-thermal noise ratio (SINR). As the result from demonstration, the proposed technique can improve and increase the interference cancellation efficiency in smart antenna better than the conventional technique.

• International Journal of Advanced Culture Technology
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• 제1권1호
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• pp.19-22
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• 2013

The basic principle of the product manufacturing technology using the 3D printing technique materializes the material including the high molecular substance or plastic and metallic dust, and etc. the product into the laminate additive manufacturing according to the design diagram gradually. It is applied to the various industrial field including the field of food division, field of home appliances, field of medicine, field of mechanical department and construction, etc.. The global development case of 3D printing technique is the next. This study described global technology and market trends. Afterward, 3D printing technique manages the important role when it exceeds the product manufacturing view just and is grafted with the various technology including the biotechnology, nanotechnology, and etc. and it improves the quality of the human life.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1375-1384
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• 2014

Flashover of power transmission line insulators is a major threat to the reliable operation of power system. This paper deals with the flashover prediction of polymeric insulators used in power transmission line applications using the novel condition monitoring technique developed by PD signal time-frequency map and neural network technique. Laboratory experiments on polymeric insulators were carried out as per IEC 60507 under AC voltage, at different humidity and contamination levels using NaCl as a contaminant. Partial discharge signals were acquired using advanced ultra wide band detection system. Salient features from the Time-Frequency map and PRPD pattern at different pollution levels were extracted. The flashover prediction of polymeric insulators was automated using artificial neural network (ANN) with back propagation algorithm (BPA). From the results, it can be speculated that PD signal feature extraction along with back propagation classification is a well suited technique to predict flashover of polymeric insulators.