• Title/Summary/Keyword: Constraints Theory

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Issues and Challenges in the Extraction and Mapping of Linked Open Data Resources with Recommender Systems Datasets

  • Nawi, Rosmamalmi Mat;Noah, Shahrul Azman Mohd;Zakaria, Lailatul Qadri
    • Journal of Information Science Theory and Practice
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    • v.9 no.2
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    • pp.66-82
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    • 2021
  • Recommender Systems have gained immense popularity due to their capability of dealing with a massive amount of information in various domains. They are considered information filtering systems that make predictions or recommendations to users based on their interests and preferences. The more recent technology, Linked Open Data (LOD), has been introduced, and a vast amount of Resource Description Framework data have been published in freely accessible datasets. These datasets are connected to form the so-called LOD cloud. The need for semantic data representation has been identified as one of the next challenges in Recommender Systems. In a LOD-enabled recommendation framework where domain awareness plays a key role, the semantic information provided in the LOD can be exploited. However, dealing with a big chunk of the data from the LOD cloud and its integration with any domain datasets remains a challenge due to various issues, such as resource constraints and broken links. This paper presents the challenges of interconnecting and extracting the DBpedia data with the MovieLens 1 Million dataset. This study demonstrates how LOD can be a vital yet rich source of content knowledge that helps recommender systems address the issues of data sparsity and insufficient content analysis. Based on the challenges, we proposed a few alternatives and solutions to some of the challenges.

A Study on Autonomous Stair-climbing System Using Landing Gear for Stair-climbing Robot (계단 승강 로봇의 계단 승강 시 랜딩기어를 활용한 자율 승강 기법에 관한 연구)

  • Hwang, Hyun-Chang;Lee, Won-Young;Ha, Jong-Hee;Lee, Eung-Hyuck
    • Journal of IKEEE
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    • v.25 no.2
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    • pp.362-370
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    • 2021
  • In this paper, we propose the Autonomous Stair-climbing system based on data from ToF sensors and IMU in developing stair-climbing robots to passive wheelchair users. Autonomous stair-climbing system are controlled by separating the timing of landing gear operation by location and utilizing state machines. To prove the theory, we construct and experiment with standard model stairs. Through an experiment to get the Attack angle, the average error of operating landing gear was 2.19% and the average error of the Attack angle was 2.78%, and the step division and status transition of the autonomous stair-climbing system were verified. As a result, the performance of the proposed techniques will reduce constraints of transportation handicapped.

Optimal design of a lightweight composite sandwich plate used for airplane containers

  • Al-Fatlawi, Alaa;Jarmai, Karoly;Kovacs, Gyorgy
    • Structural Engineering and Mechanics
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    • v.78 no.5
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    • pp.611-622
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    • 2021
  • Composite material-due to low density-causes weight savings, which results in lower fuel consumption of transport vehicles. The aim of the research was to change the existing base-plate of the aluminum airplane container with the composite sandwich plate in order to reduce the weight of the containers of cargo aircrafts. The newly constructed sandwich plate consists of aluminum honeycomb core and composite face-sheets. The face-sheets consist of glass or carbon or hybrid fiber layers. The orientations of the fibers in the face-sheets were 0°, 90° and ±45°. Multi-objective optimization method was elaborated for the newly constructed sandwich plates. Based on the design aim, the importance of the objective functions (weight and cost of sandwich plates) was the same (50%). During the optimization nine design constraints were considered: stiffness, deflection, facing stress, core shear stress, skin stress, plate buckling, shear crimping, skin wrinkling, intracell buckling. The design variables were core thickness and number of layers of the face-sheets. During the optimization both the Weighted Normalized Method of the Excel Solver and the Genetic Algorithm Solver of Matlab software were applied. The mechanical properties of composite face-sheets were calculated by Laminator software according to the Classical Lamination Plate Theory and Tsai-Hill failure criteria. The main added-value of the study is that the multi-objective optimization method was elaborated for the newly constructed sandwich structures. It was confirmed that the optimal new composite sandwich construction-due to weight savings and lower fuel consumption of cargo aircrafts - is more advantageous than conventional all-aluminum container.

A Study on the Blockchain-Based Insurance Fraud Prediction Model Using Machine Learning (기계학습을 이용한 블록체인 기반의 보험사기 예측 모델 연구)

  • Lee, YongJoo
    • Journal of Convergence for Information Technology
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    • v.11 no.6
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    • pp.270-281
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    • 2021
  • With the development of information technology, the size of insurance fraud is increasing rapidly every year, and the method is being organized and advanced in conspiracy. Although various forms of prediction models are being studied to predict and detect this, insurance-related information is highly sensitive, which poses a high risk of sharing and access and has many legal or technical constraints. In this paper, we propose a machine learning insurance fraud prediction model based on blockchain, one of the most popular technologies with the recent advent of the Fourth Industrial Revolution. We utilize blockchain technology to realize a safe and trusted insurance information sharing system, apply the theory of social relationship analysis for more efficient and accurate fraud prediction, and propose machine learning fraud prediction patterns in four stages. Claims with high probability of fraud have the effect of being detected at a higher prediction rate at an earlier stage, and claims with low probability are applied differentially for post-reference management. The core mechanism of the proposed model has been verified by constructing an Ethereum local network, requiring more sophisticated performance evaluations in the future.

A simplified directly determination of natural frequencies of CNT: Via aspect ratio

  • Banoqitah, Essam Mohammed;Hussain, Muzamal;Khadimallah, Mohamed A.;Ghandourah, Emad;Yahya, Ahmad;Basha, Muhammad;Alshoaibi, Adil
    • Advances in nano research
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    • v.13 no.3
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    • pp.207-216
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    • 2022
  • In this paper, a novel model is developed for frequency behavior of single walled carbon nanotubes. The governing equation of motion is constructed method based on the Sander theory using Rayleigh-Ritz's method The frequencies enhances on increasing the power law index using simply supported, clamped and clamped free end conditions. The frequency curve for C-F is less than other conditions. It is due to the physical constraints which are applied on the edge of the CNT. It is observed that the C-F boundary condition have less frequencies from the other two conditions. The frequency phenomena for zigzag are insignificant throughout the aspect ratio. Moreover when index of power law is increased then frequencies increases for all boundary conditions. The natural frequency mechanism for the armchair (10, 10) for various values of power law index with different boundary conditions is investigated. Here frequencies decrease on increases the aspect ratio for all boundary conditions. The frequency curves of SS-SS edge condition is composed between the C-C and C-F conditions. The curves of frequency are less significant from small aspect ratio (L/d = 4.86 ~ 8.47) and decreases fast for greater ratios. It is found that the frequencies via aspect ratios, armchair (10, 10) have higher values from zigzag (10, 0). It is due to the material structure which is made by the carbon nanotubes. The power law index have momentous effect on the vibration of single walled carbon nanotubes. The present frequency result is also compared numerically experimentally with Raman Spectroscopy.

Putting Images into Second Language: Do They Survive in the Written Drafts?

  • Huh, Myung-Hye
    • Journal of English Language & Literature
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    • v.56 no.6
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    • pp.1255-1279
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    • 2010
  • Much has already been learned about what goes on in the minds of second language writers as they compose, yet, oddly enough, until recently little in the L2 research literature has addressed writing and mental imagery together. However, images and imaging (visual thinking) play a crucial role in perception (the basis of mental imagery), in turn, affecting language, thinking, and writing. Many theorists of mental imagery also agree that more than just language accounts for how we think and that imagery is at least as crucial as language. All of these demands, to be sure, are compounded for EFL students, which is why I investigate EFL students' writing process, focusing on the use of mental imagery and its relationship to the writing. First I speculate upon some ways that imagery influences EFL students' composing processes and products. Next, I want to explore how and whether the images in a writer's mind can be shaped effectively into a linear piece of written English in one's writing. I studied two university undergraduate EFL students, L and J. They had fairly advanced levels of English proficiency and exhibited high level of writing ability, as measured by TOEFL iBT Test. Each student wrote two comparison and contrast essays: one written under specified time limitations and the other written without the pressure of time. In order to investigate whether the amount of time in itself causes differences within an individual in imagery ability, the students were placed under strict time constraints for Topic 1. But for Topic 2, they were encouraged to take as much time as necessary to complete this essay. Immediately after completing their essays, I conducted face-to-face retrospective interviews with students to prompt them for information about the role of imagery as they write. Both L and J have spent more time on their second (untimed) essays. Without time constraint, they produced longer texts on untimed essay (149 vs. 170; 186 vs 284 words). However, despite a relatively long period of time spent writing an essay, these students neither described their images nor detailed them in their essays. Although their mental imagery generated an explosion of ideas for their writings, most visual thinking must merely be a means toward an end-pictures that writers spent in purchasing the right words or ideas.

Study of a Mixed Finite Element Model for the Analysis of a Geometrically Nonlinear Plate (기하학적 비선형 판재 해석을 위한 혼합형 FE Model 연구)

  • Kim, Woo-Ram;Choi, Youn-Dae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.10
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    • pp.1427-1435
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    • 2010
  • A mixed finite element model was developed using the classical plate theory to analyze the nonlinear bending of a plate. The appropriate weight functions for the constraints integrated over the domain were determined by the Lagrange multiplier method by using the principle of minimum virtual energy; which provides the constitutive relations between force-like variables and strains. All of detail terms of element wise coefficient matrices and associate tangent matrices to be used in the Newton iterative method are presented. Then, the linear solutions of the current model and those of the traditional displacement model under the SS (simple support) boundary conditions were compared with the existing analytical solution. The post-processed images of the nonlinear results of the force-like variables are presented to show the continuity of the solutions at the joint of the element boundaries. Finally, the converged nonlinear finite element solutions of the current model are compared with those of existing traditional displacement model.

The E-Learning for Practice Training Using Augmented Reality in the College Education (증강현실을 이용한 대학 e-Learning 실습교육)

  • Lee, Ki-Ho
    • Cartoon and Animation Studies
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    • s.40
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    • pp.443-476
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    • 2015
  • The university e-learning classes give a major focused on practical training in the art and design field are opened such as theory classes. The cyber universities that fully gives on-line classes even open as theory classes. They speak about difficulty and limitation of operating cyber class with practice. So, many of them organize off-line special lecture at the classroom in weekend. In the reason of studying that has the constraints of time and space, the student wastage rates in cyber universities are going higher. This research focused on giving an efficient e-learning practice environment in college e-learning courses, and operated scholastic achievement test between the augmented reality(AR) based practice education and the existing classroom based practice education. The subjects of study were totally 84 people who are the freshmen of the design department in the two-year diploma course college. They were divided 3 groups which one was treated AR based practice e-learning and two others groups were existing classroom based practice. Each of the group took the same treated lecture during 7 weeks. The first of the outcome was the AR based practice e-learning was more effective than existing classroom based practice on the side of scholastic achievement. The second, the AR based practice e-learning aroused increasing in the interest in class on the side of attribute factors. The third, the AR based practice e-learning group made higher level of studying immersion than others. In consideration of this experiment was processed in the regular college academic course, the finding by this research shows AR based major practice e-learning is an alternative lecturing strategy what can be supplemented existing classroom based academic teaching methods.

Fatigue Constrained Topological Structure Design Considering the Stress Correction Factor (응력 수정 계수를 고려한 피로 제약 조건 구조물의 위상최적설계)

  • Kim, Daehoon;Ahn, Kisoo;Jeong, Seunghwan;Park, Soonok;Yoo, Jeonghoon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.31 no.2
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    • pp.97-104
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    • 2018
  • In this study, a structure satisfying the fatigue constraint is designed by applying the topology optimization based on the phase field design method. In order to predict life based on the stress value, high cycle fatigue failure theory in which stress acts within the range of elastic limit is discussed and three fatigue theories of modified-Goodman, Smith-Watson-Topper and Gerber theory are applied. To calculate the global maximum stress, a modified P-norm stress correction method is used. As a result, it is possible to obtain topology optimization results that minimize the volume while satisfying the fatigue constraints. By applying the phase field design method, a simple shape with a minimized gray scale was obtained, and the maximum stress value acting on the optimization result became very close to the allowable stress value due to the modified P-norm stress method. While previous studies does not consider the stress correction factor, this study proposes the determination method regarding the stress correction factor considering loading effects related to axial stress components.

A Qualitative Study on the Mental Health Social Workers' Experiences Concerning Client's Self-determination (클라이언트의 자기결정에 관한 정신보건사회복지사의 실천 경험에 대한 연구)

  • Kim, Gi-duk;Jang, Eun-sook
    • Korean Journal of Social Welfare Studies
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    • no.39
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    • pp.83-113
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    • 2008
  • The purpose of the study is to explore the mental health social workers' experiences concerning client's self-determination by grounded theory, one of the qualitative method. Although a lot of previous studies has proved that the practitioners have suffered from the ethical considerations in their practice, on which the matter of client's self-determination is centered, little attention is paid to deep exploration of practitioners' real experience about those aspects. To carry out the research question, first, through literature reviews focusing on clarify the underlying issues about client's self-determination, three intrinsic clues are found out; incompetence, medical benefits, the harm to the third party. Data obtained by in-depth interview with 10 participants are analyzed by employing the methode developed by Corbin and Strauss, which could categorize the raw data into several high-level concepts and constructs. The findings of the study show that most practitioners would consider the clients as the intrinsic subject of self-determination. Therefore, in practice, they are trying to support the client's self-determination even within the some constraints. In addition, they also experience the clients' latent potential in actualizing autonomy and self-determination, and identifies the positive effect of self-determination not only on the client's self-help and mental health but also on the practitioners themselves. The results of the study clearly suggests that it is critical to provide the practitioners with adequate ethical education and training to help them to overcome their ethical suffering concerning clients self-determination.