• Asia pacific journal of information systems
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• 제25권1호
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• pp.1-24
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• 2015

Electronic Commerce or e-commerce implies such an industry where goods and services are bought and sold over electronic systems. This is rapidly growing sectors in Bangladesh which influence local and international trade. Government of Bangladesh has also initiated quite a good number of measures for the expansion of e-commerce. However, low adoption of e-commerce is not uncommon in Bangladesh. The objective of this study is to determine the factors that influence the adoption of e-commerce services in Bangladesh. Extended version of Technology Acceptance Model (TAM) is envisaged as the theoretical backbone of the study. Reliability analysis using Cronbach's Alpha test indicates that the research model is internally consistent. The study reveals that 35 percent of respondents became interested in e-commerce services from advertisement on Internet or other electronic media. The findings of the study shows that all the four constructs, namely-Computer Self Efficacy, Perceived Credibility, Perceived Usefulness and Perceived Ease of Use have significant effect on the adoption of e-commerce. The study has also demonstrated that Perceived Usefulness appeared as the most important factor in describing user's adoption of e-commerce.

• ETRI Journal
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• 제45권5호
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• pp.822-835
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• 2023

Recent semantic segmentation frameworks usually combine low-level and high-level context information to achieve improved performance. In addition, postlevel context information is also considered. In this study, we present a Context ReFinement Network (CRFNet) and its training method to improve the semantic predictions of segmentation models of the encoder-decoder structure. Our study is based on postprocessing, which directly considers the relationship between spatially neighboring pixels of a label map, such as Markov and conditional random fields. CRFNet comprises two modules: a refiner and a combiner that, respectively, refine the context information from the output features of the conventional semantic segmentation network model and combine the refined features with the intermediate features from the decoding process of the segmentation model to produce the final output. To train CRFNet to refine the semantic predictions more accurately, we proposed a sequential training scheme. Using various backbone networks (ENet, ERFNet, and HyperSeg), we extensively evaluated our model on three large-scale, real-world datasets to demonstrate the effectiveness of our approach.

• 한국안전학회지
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• 제34권6호
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• pp.50-57
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• 2019

In this study, various types of deep learning models that have been proposed recently are classified according to data input / output types and analyzed to find the deep learning model suitable for constructing a crack detection model. First the deep learning models are classified into image classification model, object segmentation model, object detection model, and instance segmentation model. ResNet-101, DeepLab V2, Faster R-CNN, and Mask R-CNN were selected as representative deep learning model of each type. For the comparison, ResNet-101 was implemented for all the types of deep learning model as a backbone network which serves as a main feature extractor. The four types of deep learning models were trained with 500 crack images taken from real concrete structures and collected from the Internet. The four types of deep learning models showed high accuracy above 94% during the training. Comparative evaluation was conducted using 40 images taken from real concrete structures. The performance of each type of deep learning model was measured using precision and recall. In the experimental result, Mask R-CNN, an instance segmentation deep learning model showed the highest precision and recall on crack detection. Qualitative analysis also shows that Mask R-CNN could detect crack shapes most similarly to the real crack shapes.

• 한국지진공학회논문집
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• 제7권5호
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• pp.47-56
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• 2003

본 논문에서는 기존 IWAN 모델을 수정하여 사질토 지반의 반복경화 현상을 나타낼 수 있는 지반의 반복경화모델을 개발하였다. 일반적으로 동적하중을 받는 지반재료는 하중 반복회수에 따라 동적 거동특성이 변화하게 되며 이는 반복 경화 및 연화현상으로 나타난다. 본 논문에서는 등방 경화 또는 등방 연화 거동을 하는 스프링슬라이더 요소를 기존 병렬 IWAN 모델에 추가함으로써 지반의 동적 변형특성 표현이 가능하였다. 등방 경화 거동을 보이는 요소들의 항복 응력은 각각 반복 경화함수에 의하여 증가하도록 정의되었으며, 반복 경화함수는 대칭 한계를 가지는 동적 비틂전단 시험결과로부터 정의되었다. 이렇게 정의된 반복 경화함수는 지반의 동적 변형 특성을 묘사하기 위하여 하나의 독립 변수를 가지게 되며, 사용된 독립변수는 지반의 동적 한계 변형률의 특성을 포함하는 누적전단변형률로 사용되었다. 누적 전단변형률은 반복 전단한계 변형률 이상의 변형률의 누적으로 정의되며, 역재하 및 재재하 곡선에서는 Masing의 법칙을 적용하여 계산될 수 있다. 본 논문에서는 모델의 개발과정을 서술하였고, 모델에 대한 검증은 동반논문인 검증편에 설명하였다.

• 로봇학회논문지
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• 제3권4호
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• pp.315-322
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• 2008

A new soft finger mechanism using a spring as a backbone is proposed in this work. It is a 4 DOF mechanism that consists of a spring and 3 cylinders, which behave like joints with 3 up-and-down rotations and 1 left-and-right rotation. To control each joint, cylinders have small holes in their cross-sectional areas, and wires of different length are penetrated into these holes. We can control each joint by pulling the corresponding wire. The forward kinematics is solved by using the geometry of mechanism. And the relationship (Jacobian) between the linear velocity of the wires and the joint angular rate is obtained. A virtual simulator is developed to test the validity of the kinematic model. In the experiment, first, the position control is conducted by tracking a given trajectory. Second, to verify the flexibility and safety, we show that the soft finger deflects in a safe manner, in spite of the collision with environment.

• 전자공학회논문지A
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• 제28A권12호
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• pp.1-11
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• 1991

Multi rate circuit switching ISDN which assumes a star topology consisting of LANs(local area networks) interconnected through a backbone MAN (metropolitan area network) is considered. The stations are classified into two categories data and voice stations they are characterized by different arrival rate and session-length (holding time) statistics. We first model the data and voice terminals as finite-source stations and derive analytically exact expressions for the end-to-end blocking probabilities. For more exact evaluation, these probabilities are calculated in terms of three components:circuit blocking probability, destination busy probability and concurrent busy probability. For large size systems, we develop an develop an iterative algorithm that provides a computationally efficient and fast method for the calculation of the end-to-end blocking probabilities.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.242-243
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• 2006

In this work, we report the synthesis and characterization of azomethineester polymers that consist of banana-shaped mesogen in their backbone. Two parts of the key structure of five-ring bent-core mesogen were modified by connecting different angle of central unit (Ar), and introducing lateral substituent into the outer ring (X). The synthetic details includes (1) placing the dioxydodecamethylene unit as a flexible spacer, (2) possessing 2,3- or 2,7-naphthylene, or 1,2-phenylene connection on the central unit, and (3) introducing fluorine or chlorine substituent (X = F or Cl) into the outer phenylene unit.

• Macromolecular Research
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• 제8권5호
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• pp.224-230
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• 2000

Molecular mechanics technique has been used for finding energy-minimized conformation to understand the mechanism of yielding of glassy polymers in atomistic level. As a model polymer, amor- phous isotactic polypropylene (iPP) was generated by molecular mechanics and molecular dynamics methods. The stress-strain cone was successfully obtained by using molecular mechanics technique. The torsional angle distribution showed no significant change during extension, although the torsional angles of certain bonds in polymer backbone changed more largely than other bonds. No significant change in the van der Waals interaction is observed at yielding point, whereas the torsional angle energy starts to decrease at yield strain.

• Macromolecular Research
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• 제15권6호
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• pp.491-497
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• 2007

NPT Monte Carlo simulations were performed to calculate the molecular properties of syndiotactic poly(vinyl chloride) (PVC) and syndiotactic poly(vinyl alcohol) (PVA) melts using the configurational bias Monte Carlo move, concerted rotation, reptation, and volume fluctuation. The density, mean square backbone end-to-end distance, mean square radius of gyration, fractional free-volume distribution, distribution of torsional angles, small molecule solubility constant, and radial distribution function of PVC at 0.1 MPa and above the glass transition temperature were calculated/measured, and those of PVA were calculated. The calculated results were compared with the corresponding experimental data and discussed. The calculated densities of PVC and PVA were smaller than the experimental values, probably due to the very low molecular weight of the model polymer used in the simulation. The fractional free-volume distribution and radial distribution function for PVC and PVA were nearly independent of temperature.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.772-775
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• 2006

Cinnamate polymers are well known photoreactive polymers due to [2+2] cycloaddition reaction of cinnamate side group. In this work, we have found that the cinnamate side groups could be also reacted by thermal energy, and this reaction is presumed to attribute to the radical reaction of carbon double bond in the cinnamate groups. Contrary to the photocycloaddition reaction of the cinnamate side groups, the thermal reaction of cinnamate side group was closely related to the flexibility of polymer backbone. The difference of the mechanism between the photocycloaddition reaction and thermal crosslinking reaction was confirmed by $^1H-NMR$$ and $^{13}C-NMR$ analysis of the model compound.