• Title/Summary/Keyword: solution accuracy

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Vulnerabilities and Attack Methods in Visible Light Communications Channel (가시광 통신 채널의 취약성 및 공격 방법)

  • Park, So-Hyun;Joo, Soyoung;Lee, Il-Gu
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.469-471
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    • 2021
  • As wireless communication technology advances to ensure high accuracy and safety at high speeds, research and development of Visible Light Communication (VLC) technology has been accelerated as an alternative to traditional radio frequency (RF) technology. As the radio spectrum of RF communication becomes more congested and demand for bandwidth continues to increase, VLCs that can use unlicensed frequency band are proposed as a solution. However, VLC channels have broadcasting characteristics that make them easily exposed to eavesdropping and jamming attacks, and are vulnerable to MITM (Man-In-The-Middle) due to their line of sight (LOS) propagation characteristics. These attacks on VLC channels compromise the confidentiality, integrity, and availability of communications links and data, resulting in higher data retransmission rates, reducing throughput and increasing power consumption, resulting in lower data transmission efficiency. In this work, we model vulnerable VLC channels to analyze the impact of attacks and communications vulnerabilities by malicious jammers.

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Preparation and assessment of airborne fibrous reference sample for a proficiency test (국내 공기 중 섬유상 분진 숙련도 시험용 표준시료 제조 및 평가)

  • Lim, Hoju;Ryu, Jaihyuk;Choi, Sungho;Choi, Arum;Jung, Hyunsung;Ryu, Jungmin;Kim, Hyunwook;Jang, Seongki
    • Analytical Science and Technology
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    • v.22 no.5
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    • pp.369-375
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    • 2009
  • We evaluated the homogeneity and accuracy of low level airborne fibrous standard, and accomplished the proper proficiency test. We had found that the correlation of concentration of standard solution and asbestos density was 0.9863~0.9968, and concluded that the proper guideline of the analysis result was ${\mid}Z{\mid}{\leq}2$ interval of Z-score.

Mechanical and thermal stability investigation of functionally graded plates resting on visco-Pasternak foundation

  • Samira Hassiba Tagrara;Mohamed Mehdi hamri;Mahmoud Mohamed Selim Saleh;Mofareh Hassan Ghazwani;Abdelbaki Chikh;Abdelmoumen Anis Bousahla;Abdelhakim Kaci;Fouad Bourada;Abdelouahed Tounsi
    • Steel and Composite Structures
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    • v.46 no.6
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    • pp.839-856
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    • 2023
  • This work presents a simple four-unknown refined integral plate theory for mechanical and thermal buckling behaviors of functionally graded (FG) plates resting on Visco-Pasternak foundations. The proposed refined high order shear deformation theory has a new displacement field which includes indeterminate integral variables and contains only four unknowns in which any shear correction factor not used, with even less than the conventional theory of first shear strain (FSDT). Governing equations are deduced from the principle of minimum total potential energy and a Navier type analytical solution is adopted for simply supported FG plates. The Visco-Pasternak foundations is considered by adding the impact of damping to the usual foundation model which characterized by the linear Winkler's modulus and Pasternak's foundation modulus. The accuracy of the present model is demonstrated by comparing the computed results with those available in the literature. Some numerical results are presented to show the impact of material index, elastic foundation type, and damping coefficient of the foundation, on the mechanical and thermal buckling behaviors of FG plates.

Study on stability and free vibration behavior of porous FGM beams

  • Bennai, Riadh;Atmane, Redhwane Ait;Bernard, Fabrice;Nebab, Mokhtar;Mahmoudi, Noureddine;Atmane, Hassen Ait;Aldosari, Salem Mohammed;Tounsi, Abdelouahed
    • Steel and Composite Structures
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    • v.45 no.1
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    • pp.67-82
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    • 2022
  • In this paper, buckling and free vibration of imperfect, functionally graded beams, including porosities, are investigated, using a higher order shear strain theory. Due to defects during the manufacturing process, micro porosities may appear in the material, hence the appearance of this imperfection in the structure. The material properties of the beams are assumed to vary regularly, with power and sigmoid law, in the direction of thickness. A novel porosity distribution affecting the functionally graded volume fraction is presented. For the compact formulation used for cementite-based materials and already used in P-FGM, we have adapted it for the distribution of S-FGM. The equations of motion in the FG beam are derived using Hamilton's principle. The boundary conditions for beam FG are assumed to be simply supported. Navier's solution is used to obtain the closed form solutions of the FG beam. The numerical results of this work are compared with those of other published research to verify accuracy and reliability. The comparisons of different shear shape functions, the influence of porosity, thickness and inhomogeneity parameters on buckling and free vibration of the FG beam are all discussed. It is established that the present work is more precise than certain theories developed previously.

Effective ChatGPT Prompts in Mathematical Problem Solving : Focusing on Quadratic Equations and Quadratic Functions (수학 문제 해결에서 효과적인 ChatGPT의 프롬프트 고찰: 이차방정식과 이차함수를 중심으로)

  • Oh, Se Jun
    • Communications of Mathematical Education
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    • v.37 no.3
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    • pp.545-567
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    • 2023
  • This study investigates effective ChatGPT prompts for solving mathematical problems, focusing on the chapters of quadratic equations and quadratic functions. A structured prompt was designed, following a sequence of 'Role-Rule-Example Solution-Problem-Process'. In this study, an artificial intelligence model combining GPT-4, Wolfram plugin, and Advanced Data Analysis was utilized. Wolfram was used as the primary tool for calculations to reduce computational errors. When using the structured prompt, the accuracy rate for problems from nine high school mathematics textbooks on quadratic equations and quadratic functions was 91%, showing higher performance compared to zero-shot prompts. This confirmed the effectiveness of the structured prompts in solving mathematical problems. The structured prompts designed in this study can contribute to the development of intelligent information systems for personalized and customized education.

Research on Developing a Conversational AI Callbot Solution for Medical Counselling

  • Won Ro LEE;Jeong Hyon CHOI;Min Soo KANG
    • Korean Journal of Artificial Intelligence
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    • v.11 no.4
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    • pp.9-13
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    • 2023
  • In this study, we explored the potential of integrating interactive AI callbot technology into the medical consultation domain as part of a broader service development initiative. Aimed at enhancing patient satisfaction, the AI callbot was designed to efficiently address queries from hospitals' primary users, especially the elderly and those using phone services. By incorporating an AI-driven callbot into the hospital's customer service center, routine tasks such as appointment modifications and cancellations were efficiently managed by the AI Callbot Agent. On the other hand, tasks requiring more detailed attention or specialization were addressed by Human Agents, ensuring a balanced and collaborative approach. The deep learning model for voice recognition for this study was based on the Transformer model and fine-tuned to fit the medical field using a pre-trained model. Existing recording files were converted into learning data to perform SSL(self-supervised learning) Model was implemented. The ANN (Artificial neural network) neural network model was used to analyze voice signals and interpret them as text, and after actual application, the intent was enriched through reinforcement learning to continuously improve accuracy. In the case of TTS(Text To Speech), the Transformer model was applied to Text Analysis, Acoustic model, and Vocoder, and Google's Natural Language API was applied to recognize intent. As the research progresses, there are challenges to solve, such as interconnection issues between various EMR providers, problems with doctor's time slots, problems with two or more hospital appointments, and problems with patient use. However, there are specialized problems that are easy to make reservations. Implementation of the callbot service in hospitals appears to be applicable immediately.

A Study on Automatic Vehicle Extraction within Drone Image Bounding Box Using Unsupervised SVM Classification Technique (무감독 SVM 분류 기법을 통한 드론 영상 경계 박스 내 차량 자동 추출 연구)

  • Junho Yeom
    • Land and Housing Review
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    • v.14 no.4
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    • pp.95-102
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    • 2023
  • Numerous investigations have explored the integration of machine leaning algorithms with high-resolution drone image for object detection in urban settings. However, a prevalent limitation in vehicle extraction studies involves the reliance on bounding boxes rather than instance segmentation. This limitation hinders the precise determination of vehicle direction and exact boundaries. Instance segmentation, while providing detailed object boundaries, necessitates labour intensive labelling for individual objects, prompting the need for research on automating unsupervised instance segmentation in vehicle extraction. In this study, a novel approach was proposed for vehicle extraction utilizing unsupervised SVM classification applied to vehicle bounding boxes in drone images. The method aims to address the challenges associated with bounding box-based approaches and provide a more accurate representation of vehicle boundaries. The study showed promising results, demonstrating an 89% accuracy in vehicle extraction. Notably, the proposed technique proved effective even when dealing with significant variations in spectral characteristics within the vehicles. This research contributes to advancing the field by offering a viable solution for automatic and unsupervised instance segmentation in the context of vehicle extraction from image.

Sensitivity Evaluation and Approximate Optimization Analysis for Structure Design of Module Hull Type Trimaran Pontoon Boat (모듈 선체형 삼동 폰툰 보트의 구조설계 민감도 평가와 근사 최적화 해석)

  • Bo-Youp Choi;Chang-Ryeon Son;Joon-Sik Son;Min-Ho Park;Chang-Yong Song
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.6_3
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    • pp.1279-1288
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    • 2023
  • Recently, domestic leisure boats have been actively researching eco-friendly product development to enter the global market. Since the hulls of existing leisure boats are mainly made of fiber reinforced plastic (FRP) or aluminum, design techniques for securing structural safety by applying related materials have been mainly studied. In this study, an initial structural design safety assessment of a trimaran pontoon leisure boat with a modular hull structure and eco-friendly high-density polyethylene (HDPE) material was conducted, and sensitivity evaluation and optimization analysis for lightweight design were performed. The initial structural design safety assessment was carried out by creating a finite element analysis model and applying the loading conditions specified in the ship classification regulation to check whether the specified allowable stresses are satisfied. For the sensitivity evaluation, the influence of stress and weight of each hull structural member was evaluated using the orthogonal array design of experiments method, and an approximate model based on the response surface method was generated using the results of the design of experiments. The optimization analysis set the thickness of the hull structural members as the design variable and considered the optimal design formulation to minimize the weight while satisfying the allowable stress. The algorithm of the optimization analysis applied the Gradient-population Based Optimizer (GBO) to improve the accuracy of the optimal solution convergence while reducing the numerical cost. Through this study, the optimal design of a newly developed eco-friendly trimaran pontoon leisure boat with a weight reduction of 10% was presented.

Evaluation of the Feasibility of the Sample Pretreatment and Nile Red Fluorescence Staining Methods for Quantification of Microplastics in Wastewater Samples (하수처리장 유입⋅유출⋅공정수 내 미세플라스틱 분석을 위한 시료 전처리 기법과 Nile Red 형광염색법 적용성 평가)

  • Jae In Kim;Nguyen Thu Huong;Byung Joon Lee
    • Journal of Korean Society on Water Environment
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    • v.40 no.1
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    • pp.36-46
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    • 2024
  • Microplastics in water resources have been recognized as a serious problem. The discharge of microplastics from wastewater treatment plants is considered a major contributor to environmental pollution in water resources. However, a reliable analytical method for quantifying microplastics in wastewater treatment plants has not yet been established. This study proposes a reliable, quick, and easy analytical method for quantifying microplastics. For the removal of organic particles, preprocessing steps were applied including oxidation, sonication, washing, and sieving. Nile Red staining was used to visualize microplastics, and quantitative analysis was conducted using fluorescent imaging. The stained microplastics were ultimately quantified through image analysis software. Among the preprocessing steps, sonication and washing stages were particularly effective in efficiently removing interfering substances from wastewater, enhancing the accuracy of the microplastic analysis. Additionally, various solvents (methanol, acetone, and N-hexane) for the Nile Red staining solution were tested. When N-hexane was applied as the solvent, the quantity of stained microplastics was lower compared to methanol and acetone. This suggests that N-hexane has a greater potential of reducing false staining and counting of non-plastic particles. In summary, this research demonstrates a robust method for quantifying microplastics in wastewater treatment plants by employing effective preprocessing steps and optimizing the staining process with Nile Red and N-hexane.

A Design and Implementation of Generative AI-based Advertising Image Production Service Application

  • Chang Hee Ok;Hyun Sung Lee;Min Soo Jeong;Yu Jin Jeong;Ji An Choi;Young-Bok Cho;Won Joo Lee
    • Journal of the Korea Society of Computer and Information
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    • v.29 no.5
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    • pp.31-38
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    • 2024
  • In this paper, we propose an ASAP(AI-driven Service for Advertisement Production) application that provides a generative AI-based automatic advertising image production service. This application utilizes GPT-3.5 Turbo Instruct to generate suitable background mood and promotional copy based on user-entered keywords. It utilizes OpenAI's DALL·E 3 model and Stability AI's SDXL model to generate background images and text images based on these inputs. Furthermore, OCR technology is employed to improve the accuracy of text images, and all generated outputs are synthesized to create the final advertisement. Additionally, using the PILLOW and OpenCV libraries, text boxes are implemented to insert details such as phone numbers and business hours at the edges of promotional materials. This application offers small business owners who face difficulties in advertising production a simple and cost-effective solution.