• 대한임베디드공학회논문지
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• 제15권6호
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• pp.281-287
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• 2020

In this paper, we propose a method for estimating a walking direction by which a mobile robots follows a person using TRT (Tensor RT) pose, which is motion recognition based on deep learning. Mobile robots can measure individual movements by recognizing key points on the person's pelvis and determine the direction in which the person tries to move. Using these information and the distance between robot and human, the mobile robot can follow the person stably keeping a safe distance from people. The TRT Pose only extracts key point information to prevent privacy issues while a camera in the mobile robot records video. To validate the proposed technology, experiment is carried out successfully where human walks away or toward the mobile robot in zigzag form and the robot continuously follows human with prescribed distance.

• 식물조직배양학회지
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• 제25권3호
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• pp.183-187
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• 1998

한란(Cymbidium kanran)의 근경에 돌연변이 물질인 EMS를 처리하여 엽록소변이 식물체를 유도하였다. 한란종자를 발아시켜서 근경을 유도할 때 종자에 40분간 초음파 처리한 것이 무처리구에 비하여 발아율이 5.5배 정도 높았다. EMS 0.2%를 포함한 근경증식용 액체배지에서 3주간 배양하였을 경우에 50-60%정도의 근경이 갈변되었다. 갈변된 근경을 근경증식용 고체배지에서 배양하였을 경우에 근경조직의 일부분으로부터 새로운 근경의 증식의 관찰되었고, 이러한 근경조직을 절단하여 1년간 계단배양하던중에 분열조직의 일부분에서 색소변이 근경이 관찰되었다. 색소변이 근경은 나선형의 줄무늬가 가장 많았고, 그 외 엷은 노란색과 흰색의 근경이 분리되었다. 나선형의 근경에서 유도된 식물체는 잎에 무늬가 전혀 없는 녹색의 식물체 또는 줄무늬가 들어 있는 식물체가 유도되었다. 그러나 엷은 노란색 근경에서 유도된 식물체는 노란색 줄무늬가 있는 식물체로, 흰색 근경으로부터 유도된 식물체는 백화된 식물체로만 분화하였다. 이상의 결과 한란근경을 이용한 색소변이식물체의 유도에 있어서 배양중인 근경에 EMS처리가 효과적인 것을 보여주었다. 이러한 방법을 다른 식물에 적용하면 색소변이 식물체를 개발할 수 있으리라 생각된다.

• The Journal of Advanced Prosthodontics
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• 제14권2호
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• pp.88-95
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• 2022

PURPOSE. This study investigated the accuracy of full-arch intraoral scans obtained by various scan strategies with the segmental scan and merge methods. MATERIALS AND METHODS. Seventy intraoral scans (seven scans per group) were performed using 10 scan strategies that differed in the segmental scan (1, 2, or 3 segments) and the scanning motion (straight, zigzag, or combined). The three-dimensional (3D) geometric accuracy of scan images was evaluated by comparison with a reference image in an image analysis software program, in terms of the arch shape discrepancies. Measurement parameters were the intermolar distance, interpremolar distance, anteroposterior distance, and global surface deviation. One-way analysis of variance and Tukey honestly significance difference post hoc tests were carried out to compare differences among the scan strategy groups (α = .05). RESULTS. The linear discrepancy values of intraoral scans were not different among scan strategies performed with the single scan and segmental scan methods. In general, differences in the scan motion did not show different accuracies, except for the intermolar distance measured under the scan conditions of a 3-segmental scan and zigzag motion. The global surface deviations were not different among all scan strategies. CONCLUSION. The segmental scan and merge methods using two scan parts appear to be reliable as an alternative to the single scan method for full-arch intraoral scans. When three segmental scans are involved, the accuracy of complete arch scan can be negatively affected.

• Advances in nano research
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• 제14권1호
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• pp.1-15
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• 2023

Driven by the scaling down of transistor node technology, graphene became of interest to many researchers following the success of its fabrication as graphene nanoribbons (GNRs). However, during the fabrication of GNRs, it is not uncommon to have defects within the GNR structures. Scaling down node technology also changes the modelling approach from the classical Boltzmann transport equation to the quantum transport theory because the quantum confinement effects become significant at sub-10 nanometer dimensions. The aim of this study is to examine the effect of Stone-Wales defects on the electronic properties of GNRs using a tight-binding model, based on Non-Equilibrium Green's Function (NEGF) via numeric computation methods using MATLAB. Armchair and zigzag edge defects are also implemented in the GNR structures to mimic the practical fabrication process. Electronic properties of pristine and defected GNRs of various lengths and widths were computed, including their band structure and density of states (DOS). The results show that Stone-Wales defects cause fluctuation in the band structure and increase the bandgap values for both armchair GNRs (AGNRs) and zigzag GNRs (ZGNRs) at every simulated width. In addition, Stone-Wales defects reduce the numerical computation DOS for both AGNRs and ZGNRs. However, when the lengths of the structures increase with fixed widths, the effect of the Stone-Wales defects become less significant.

• 한국의류학회지
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• 제42권3호
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• pp.474-485
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• 2018

Smart sensors and connected devices have changed the concept of garments along with IT technology convergent garments that transform the performance of basic functions. Various types of products have been researched and developed due to the increased interest in smart clothing; in addition, studies based on physical and mechanical properties have also been actively studied to improve accuracy and reliability. This study represents a basic study for the development of smart textiles based on motion recognition for the surfing practice of beginners interested in IT convergence type. A physical durability evaluation of conductive yarn according to sewing method was later carried out. This study is a conditional specimen sewn with cotton lower thread and 100mm pattern length based on the results of previous studies. The durability of the conductive yarn according to the sewing method was evaluated according to the sewing method. Durability was evaluated by two kinds of repeated strain and abrasion tests. The specimen with applied cotton in a lower thread zigzag pattern 2mm stitch size 100mm stitch length was shown to have the most suitable durability for smart textile.

• 정보처리학회논문지A
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• 제12A권4호
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• pp.321-326
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• 2005

본 논문에서는 질점-스프링 모델(mass-spring model)에 기반한 대화형 천 시뮬레이션(interactive cloth simulation) 기법을 제시하며, 특히 소수의 질점들(mass-points)에 상대적으로 강한 힘이 가해졌을 경우 사실적으로 천을 시뮬레이션하는 방법에 초점을 맞추었다. 본 논문에서 제시하는 방법은 소수의 점들에 대해 가해진 힘을 모든 질점들에 분산시킴으로써 의사 실시간(pseudo real-time) 내에 시뮬레이션을 수행하며, 이는 기존의 방법들에 비해 수행속도 면에서 매우 효율적이다. 또한, Provot[9]의 역동역학 방법(inverse dynamic method)을 사용하여 초탄성(super-elasticity) 현상을 해결한 뒤, 인접한 질점 간의 각도를 조정함으로써 초탄성 효과에 의해 발생하는 지그재그(zigzag) 현상을 제거하여 사실적으로 천을 시뮬레이션한다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 추계학술발표대회 논문집
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• pp.191-194
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• 2001

A partially coupled thermo-piezoelectric-mechanical triangular finite element model of composite laminates with surface bonded piezoelectric actuators, subjected to externally applied mechanical load, temperature change load, electric field load is developed. The governing differential equations are obtained by applying the principle of free energy and variational techniques. A higher order zigzag theory displacement field is employed to accurately capture the transverse shear and normal effects in laminated composite plates of arbitrary thickness. Nonconforming shape functions by Specht are employed in the transverse displacement variables. Numerical examples demonstrate the accuracy and efficiency of the proposed triangular plate element.

• 한국자동차공학회논문집
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• 제6권5호
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• pp.146-152
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• 1998

Recently, for the development of vehicle structures and components there is a tendency to increase using numerical simulation methods compared with practical tests for the estimation of the fatigue strength. In this study, an integrated powerful methodology is suggested for fatigue strength evaluation through development of the interface program to integrate dynamic analysis quasi-static stress analysis and fatigue analysis, which were so far used independently. To verify the presented evaluation method, a single and zigzag bump run test, 4-post road load simulation and driving durability test have been performed. The prediction results show a good agreement between analysis and test. This research indicates that the integrated life prediction methodology can be used as a reliable design tool in the pre-prototype and prototype development stage, to reduce the expense and time of design iteration.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.442-442
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• 2011

Electronic and magnetic properties of bilayer zigzag graphene nanoribbon (bZGNR) are studied using pseudopotential density functional method. The edge atoms in the top and bottom layers of bZGNR make a weak hybridization, which leads to electronic structures different from monolayer ZGNR. For asymmetric bZGNR, where the top and bottom layers have different widths, one edge is pinched by the interlayer bonding and the other sustains antiferromagnetic ordering. A small amount of charge transfer occurs from narrower to wider layer, producing spin-polarized electron and hole pockets. External electric field produces asymmetric energy-gap opening for each spin component, inducing half-metallicity in bZGNR.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.663-668
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• 2007

An enhanced first shear deformation theory for composite plate is developed. The detailed process is as follows. Firstly, the theory is formulated by modifying higher order zigzag theory. That is, the higher order theory is separated into the warping function representing the higher order terms and lower order terms. Secondly, the relationships between higher order zig-zag field and averaged first shear deformation field based on the Reissner-Mindlin's plate theory are derived. Lastly, the effective shear modulus is calculated by minimizing error between higher order energy and first order energy. Then the governing equation of FSDT is solved by substituting shear modulus into effective shear modulus. The recovery processing with the nodal unknown obtained from governing equation is performed. The accuracy of the present proposed theory is demonstrated through numerical examples. The proposed method will serve as a powerful tool in the prediction of laminated composite plate.