• Title/Summary/Keyword: Experimental Design Technique

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An Analysis of Educational Capacity Prediction according to Pre-survey of Satisfaction using Random Forest (랜덤 포레스트를 활용한 만족도 사전조사에 따른 교육 역량 예측 분석)

  • Nam, Kihun
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.6
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    • pp.487-492
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    • 2022
  • Universities are looking for various methods to enhance educational competence level suitable for the rapidly changing social environment. This study suggests a method to promote academic and educational achievements by reducing drop-out rate from their majors through implementation of pre-survey of satisfaction that revised and complemented survey items. To supplement the CQI method implemented after a general satisfaction survey, a pre-survey of satisfaction was carried out. To consolidate students' competences, this study made prediction and analysis of data with more importance possible using the Random Forest of the machine learning technique that can be applied to AI Medici platform, whose design is underway. By pre-processing the pre-survey of satisfaction, the students information enrolled in classes were defined as an explanatory variable, and they were classified, and a model was created and learning was conducted. For the experimental environment, the algorithms and sklearn library related in Jupyter notebook 3.7.7, Python 3.7 were used together. This study carried out a comparative analysis of change in educational satisfaction survey, carried out after classes, and trends in the drop-out students by reflecting the results of the suggested method in the classes.

Evaluation of delamination in the drilling of CFRP composites

  • Feroz, Shaik;Ramakrishna, Malkapuram;K. Chandra, Shekar;P. Dhaval, Varma
    • Advances in materials Research
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    • v.11 no.4
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    • pp.375-390
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    • 2022
  • Carbon Fiber Reinforced Polymer (CFRP) composite provides outstanding mechanical capabilities and is therefore popular in the automotive and aerospace industries. Drilling is a common final production technique for composite laminates however, drilling high-strength composite laminates is extremely complex and challenging. The delamination of composites during the drilling at the entry and exit of the hole has a severe impact on the results of the holes surface and the material properties. The major goal of this research is to investigate contemporary industry solutions for drilling CFRP composites: enhanced edge geometries of cutting tools. This study examined the occurrence of delamination at the entry and exit of the hole during the drilling. For each of the 80°, 90°, and 118°point angle uncoated Brad point, Dagger, and Twist solid carbide drills, Taguchi design of experiments were undertaken. Cutting parameters included three variable cutting speeds (100-125-150 m/min) and feed rates (0.1-0.2-0.3 mm/rev). Brad point drills induced less delamination than dagger and twist drills, according to the research, and the best cutting parameters were found to be a combination of maximum cutting speed, minimum feed rate, and low drill point angle (V:150 m/min, f: 0.1 mm/rev, θ: 80°). The feed rate was determined to be the most efficient factor in preventing hole entry and exit delamination using analysis of variance (ANOVA). Regression analysis was used to create first-degree mathematical models for each cutting tool's entrance and exit delamination components. The results of optimization, mathematical modelling, and experimental tests are thought to be reasonably coherent based on the information obtained.

Seismic Performance Evaluation of Dry Precast Concrete Beam-Column Connections with Special Moment Frame Details (특수모멘트골조 상세를 갖는 건식 프리캐스트 콘크리트 보-기둥 접합부의 내진성능평가)

  • Kim, Seon Hoon;Lee, Deuck Hang;Kim, Yong Kyeom;Lee, Sang Won;Yeo, Un Yong;Park, Jung Eun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.27 no.5
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    • pp.203-211
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    • 2023
  • For fast-built and safe precast concrete (PC) construction, the dry mechanical splicing method is a critical technique that enables a self-sustaining system (SSS) during construction with no temporary support and minimizes onsite jobs. However, due to limited experimental evidence, traditional wet splicing methods are still dominantly adopted in the domestic precast industry. For PC beam-column connections, the current design code requires achieving emulative connection performances and corresponding structural integrity to be comparable with typical reinforced concrete (RC) systems with monolithic connections. To this end, this study conducted the standard material tests on mechanical splices to check their satisfactory performance as the Type 2 mechanical splice specified in the ACI 318 code. Two PC beam-column connection specimens with dry mechanical splices and an RC control specimen as the special moment frame were subsequently fabricated and tested under lateral reversed cyclic loadings. Test results showed that the seismic performances of all the PC specimens were fully comparable to the RC specimen in terms of strength, stiffness, energy dissipation, drift capacity, and failure mode, and their hysteresis responses showed a mitigated pinching effect compared to the control RC specimen. The seismic performances of the PC and RC specimens were evaluated quantitatively based on the ACI 374 report, and it appeared that all the test specimens fully satisfied the seismic performance criteria as a code-compliant special moment frame system.

Effects of Abdominal Breathing on Preterm Labor Anxiety (복식호흡이 조기진통 임부의 불안에 미치는 효과)

  • Shim, Joung-Ohn;Chang, Soon-Bok
    • Women's Health Nursing
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    • v.12 no.2
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    • pp.106-114
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    • 2006
  • Purpose: The purpose of this study was to explore the effects of abdominal breathing on relieving anxiety in women diagnosed with preterm labor. Method: This was a pilot study, which was based on a repeated pre-post experiment design without a control group. Seven patients with preterm labor who were admitted to Y university medical center, Seoul, Korea, participated in the experiment. They were under receiving ritodrine hydrochloride(Yutopa) as tocolytic therapy and did not have any other complications. The patients were taught abdominal breathing, which is a modified version of Mason's breathing technique. The experimental treatments were done 33 times from February 18 to June 19 in 2005. Result: After abdominal breathing, the average psychological anxiety level decreased significantly. The physical anxiety levels of preterm labor patients were measured by blood pressure, pulse, and skin temperature. After abdominal breathing, the average systolic and diastolic blood pressure decreased from 117.3mmHg to 107.6 mmHg (z=-3.85, p<.001) and from 67.3mmHg to 62.7 mmHg (z=-3.14, p<.005), respectively. The average pulse rate also decreased from 97.2/min to 89.8/mim (z=-4.76, p<.001). The average skin temperature increased from 94.0 to 94.9(z=-4.80. p<.001). Conclusion: Abdominal breathing is effective for relieving anxiety of women diagnosed with preterm labor. This study, however, has been limited to short-term effects, and therefore further studies are required in order to examine the long-term effects of abdominal breathing.

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Shaping Formation and Behaviour Characteristic for SCST Structure by Cable-tensioning (Cable-tensioning에 의한 SCST 구조의 형상 형성과 거동 특성)

  • Kim, Jin-Woo;Kwon, Min-Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6A
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    • pp.819-825
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    • 2008
  • This paper describes the shaping formation and the erection of SCST structure by cable-tensioning. It could be a fast and economical method for constructing the space structure consisted with uniform pyramids by cable-tensioning of the cable in bottom chords. In the initial layout, the top chords and web members are left at their true length, the bottom chords are given gaps in proportion to the desired final shape. The feasibility of the proposed shaping method and the reliability of the established geometric model were confirmed with nonlinear finite element analysis and an experimental investigation on small scale and full size test models. As a result, the behaviour characteristic of MERO joint is very significant in shaping analysis of space structure. This study suggests the most reasonable modeling technique for the prediction of shaping in practices. And it is shown the characteristic of the behavior in shaping test for practical design purposes.

Marked Corridor 20 Meters Brief Walking Aerobic Exercise Improves the Quality of Life and Functional Capability of Stroke Survivor Outpatients in Tertiary Hospitals in Osogbo, Nigeria

  • Ojo, Israel Arogundade;Dominic, Olufunmilola Leah;Adeyemi, Wale Johnson
    • Journal of the Korean Society of Physical Medicine
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    • v.17 no.2
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    • pp.41-51
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    • 2022
  • PURPOSE: The functional limitations in stroke survivors promote sedentary lifestyles and quality of life inadequacies, but there is increasing evidence that this could be minimized by physical exercise. Therefore, this study examined the effects of physical exercise on the quality of life (QoL) and functional capacity (ability to stand up from a sitting position) among stroke survivors drafted from two tertiary hospitals in Osogbo, Nigeria. METHODS: A purposive sampling technique was used to select 21 registered right or left outpatient hemiplegic stroke survivors in a pre- and post-test experimental research design. The research questions were presented using descriptive statistics of frequency, percentage, mean and standard deviation, while an Analysis of Variance (ANOVA) was used to test the study hypothesis at the .05 alpha level for significance. RESULTS: Compared to the baseline (week 0), there were significant increases in the general quality of life, healthy well-being, physical exercise, pain perception, and environmental domains of QOL among the survivors in week four. Moreover, a significant increase was observed in these indices in week eight, compared to week four, except for the pain perception domain. Compared to the baseline, there was a significant decrease in the time it took the stroke survivors to stand up from a sitting position in week four. A significant decrease was observed in this index in week eight compared to week four. CONCLUSION: Marked corridor 20 meters brief walking exercise for eight weeks significantly improved the quality of life and ability to stand up from a sitting position in stroke survivors in Osogbo, Nigeria.

Cascade Fusion-Based Multi-Scale Enhancement of Thermal Image (캐스케이드 융합 기반 다중 스케일 열화상 향상 기법)

  • Kyung-Jae Lee
    • The Journal of the Korea institute of electronic communication sciences
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    • v.19 no.1
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    • pp.301-307
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    • 2024
  • This study introduces a novel cascade fusion architecture aimed at enhancing thermal images across various scale conditions. The processing of thermal images at multiple scales has been challenging due to the limitations of existing methods that are designed for specific scales. To overcome these limitations, this paper proposes a unified framework that utilizes cascade feature fusion to effectively learn multi-scale representations. Confidence maps from different image scales are fused in a cascaded manner, enabling scale-invariant learning. The architecture comprises end-to-end trained convolutional neural networks to enhance image quality by reinforcing mutual scale dependencies. Experimental results indicate that the proposed technique outperforms existing methods in multi-scale thermal image enhancement. Performance evaluation results are provided, demonstrating consistent improvements in image quality metrics. The cascade fusion design facilitates robust generalization across scales and efficient learning of cross-scale representations.

Personalized Media Control Method using Probabilistic Fuzzy Rule-based Learning (확률적 퍼지 룰 기반 학습에 의한 개인화된 미디어 제어 방법)

  • Lee, Hyong-Euk;Kim, Yong-Hwi;Lee, Tae-Youb;Park, Kwang-Hyun;Kim, Yong-Soo;Cho, Joon-Myun;Bien, Z. Zenn
    • Journal of the Korean Institute of Intelligent Systems
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    • v.17 no.2
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    • pp.244-251
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    • 2007
  • Intention reading technique is essential to provide personalized services toward more convenient and human-friendly services in complex ubiquitous environment such as a smart home. If a system has knowledge about an user's intention of his/her behavioral pattern, the system can provide mote qualified and satisfactory services automatically in advance to the user's explicit command. In this sense, learning capability is considered as a key function for the intention reading technique in view of knowledge discovery. In this paper, ore introduce a personalized media control method for a possible application iii a smart home. Note that data pattern such as human behavior contains lots of inconsistent data due to limitation of feature extraction and insufficiently available features, where separable data groups are intermingled with inseparable data groups. To deal with such a data pattern, we introduce an effective engineering approach with the combination of fuzzy logic and probabilistic reasoning. The proposed learning system, which is based on IFCS (Iterative Fuzzy Clustering with Supervision) algorithm, extract probabilistic fuzzy rules effectively from the given numerical training data pattern. Furthermore, an extended architectural design methodology of the learning system incorporating with the IFCS algorithm are introduced. Finally, experimental results of the media contents recommendation system are given to show the effectiveness of the proposed system.

Design of Microstrip Array Antenna for Satellite Reception (위성수신용 마이크로스트립 어레이 안테나 설계)

  • Kim, Jang-Wook;Jeon, Joo-Seong
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.10
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    • pp.71-79
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    • 2014
  • In this paper, the microstrip array antenna is studied to replace the parabolic antenna in the direct satellite reception. A microstrip array antenna has been used in extremely limited area, but if it is applied to practical life like a direct satellite reception antenna, we expect that it will be used in various way. First of all, if we use a microstrip array antenna for a direct satellite reception antenna, it should be guaranteed characteristics of broadband frequency. Therefore, the goal of this paper is designing technique an antenna which guarantees broadband frequency band for a direct satellite reception. In this paper, the proposed microstrip antenna is fed by orthogonal two feed lines to a rectangular patch and a sequentially rotated feeding technique is designed proposed for a good axial ratio in broadband frequency band. The rectangular patch is designed to satellite reception band, and the width and length are W=L=8.9 mm ($0.352{\lambda}o$) respectively. The antenna's ground plane has dimensions of $250{\times}250mm$. The experimental results verify that the proposed antenna had the axial ratio of above 1dB broader than that of the conventional feeding antenna. In order to verify the performance, a $8{\times}8$ array having two pairs was fabricated and tested. The maximum gain is 20.8 dB, the sidelobe level confirm less than -10 dB. It is verified by link budget calculation that C/N=6.7 dB can be obtained for domestic use if this proposed antenna is used in Koreasat reception system.

Prediction of Mean Water Level Rise Behind Low-Crested Structures and Outflow Velocity from Openings by Using a Hybrid Method Based on Two Dimensional Model Test and Hydrodynamic Numerical Modeling (단면수리모형 및 해수유동모델링 결합기법에 의한 저마루 구조물 배후의 평균수위 상승 및 개구부 유출유속 예측)

  • Lee, Dal Soo;Lee, Ki-Jae;Yoon, Jae Seon;Oh, Sang-Ho
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.6
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    • pp.410-418
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    • 2017
  • The stability of low-crested structure (LCS) and overtopping discharge over a seawall behind the LCS are influenced by the water level behind the structure. Hence, the experimental results can be distorted unless the increase of water level is known when two-dimensional experiment is carried out. In order to estimate increase of the mean water level behind the low-crested structure, this study applied a hybrid technique that combined results of two-dimensional model test and hydrodynamic numerical modeling based on the relationship between the water level and discharge. By using this technique, the mean water level increase and flow field can be obtained almost at the same time, which resolved the above problem considerably. In addition, this method can provide an approximate information about the outflow velocity from the openings of the structure, which is helpful for selecting appropriate planar configuration of the low-crested structure.