• Title/Summary/Keyword: back analysis method

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Analysis of Vibration Characteristics of Modular Unit by Road Test (도로 주행 시험을 통한 모듈러 유닛의 진동 특성 분석)

  • Kwak, Myong Keun;Back, Jung Hoon;Seol, Wook Je
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.1
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    • pp.29-35
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    • 2019
  • The unit modular system is a type of prefabricated construction method that completes the building by uniting the modular units on site by transporting the unit module structure manufactured in the factory to the site. Since the unit module structure is not only the frame but also the finished form including the inner and outer materials, it is most likely to be brought into the field. Therefore, not only the damage of the inner and outer materials but also deformation of frame structure due to the vibration generated during the transportation of the vehicle, And it is necessary to take appropriate methods when transporting the module structure. However, there are no methods to prevent modular structure damage due to vehicle vibration in domestic and foreign modular transportation guidelines or standards. In this study, we investigate the vibrations during the vehicle transportation of the module structure through the road driving test, identify the vibration frequency characteristics of the vehicle through FFT analysis, and propose a vibration reduction methods for module transportation.

Study on the influence of Alpha wave music on working memory based on EEG

  • Xu, Xin;Sun, Jiawen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.2
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    • pp.467-479
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    • 2022
  • Working memory (WM), which plays a vital role in daily activities, is a memory system that temporarily stores and processes information when people are engaged in complex cognitive activities. The influence of music on WM has been widely studied. In this work, we conducted a series of n-back memory experiments with different task difficulties and multiple trials on 14 subjects under the condition of no music and Alpha wave leading music. The analysis of behavioral data show that the change of music condition has significant effect on the accuracy and time of memory reaction (p<0.01), both of which are improved after the stimulation of Alpha wave music. Behavioral results also suggest that short-term training has no significant impact on working memory. In the further analysis of electrophysiology (EEG) data recorded in the experiment, auto-regressive (AR) model is employed to extract features, after which an average classification accuracy of 82.9% is achieved with support vector machine (SVM) classifier in distinguishing between before and after WM enhancement. The above findings indicate that Alpha wave leading music can improve WM, and the combination of AR model and SVM classifier is effective in detecting the brain activity changes resulting from music stimulation.

Dynamic and static structure analysis of the Obermeyer gate under overflow conditions

  • Feng, Jinhai;Zhou, Shiyue;Xue, Boxiang;Chen, Diyi;Sun, Guoyong;Li, Huanhuan
    • Computers and Concrete
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    • v.29 no.4
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    • pp.209-217
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    • 2022
  • In order to analyze the static and dynamic structural characteristics of the Obermeyer gate under overflow conditions, the force characteristics and vibration characteristics of the shield plate structure are studied based on the fluid-solid coupling theory. In this paper, the effects of the flow rate, airbag pressure and overflow water level on the structural performance of shield plate of air shield dam are explored through the method of controlling variables. The results show that the maximum equivalent stress and total deformation of the shield plate decrease first and then increase with the flow velocity. In addition, they are positively correlated with the airbag pressure. What's more, we find that the maximum equivalent stress of the shield plate decreases first and then increases with the overflow water level, and the total deformation of the shield plate decreases with the overflow water level. What's more importantly, the natural frequency of the shield structure of the Obermeyer gate is concentrated at 50 Hz and 100 Hz, so there is still the possibility of resonance. Once the resonance occurs, the free edge of the shield vibrates back and forth. This work may provide a theoretical reference for the safe and stable operation of the shield of the Obermeyer gate.

Health Problems and Work impairment in Nurses Working at Community Health Centers (보건소 근무 간호사의 건강문제와 업무성과 손실)

  • Cho, Chung-Min;Kim, Kyu-Sung;Kim, Mee-Hye
    • Journal of Korean Public Health Nursing
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    • v.23 no.1
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    • pp.69-77
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    • 2009
  • Purpose: This study was conducted to investigate health problems and factors related to work impairment of nurses working at community health centers. Method: Data were collected from May 2008 to July 2008 using a structured, self - reported questionnaire for general characteristics, work-related characteristics, health problems and work impairment. The subjects were composed of 434 nurses from 25 community health centers in Seoul. Data were analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient and multiple regression analysis. Results: For present health problems, shoulder, back and neck pain were ranked the highest at (54.6%), followed by cold, GI trouble, and visual disorders. The average score of work impairment was 24.71($\pm7.14$) out of 50.0. Multiple regression analysis revealed that the major factors that affect work impairment were age and number of health problems, and that these factors explained 15% of the work impairment. Conclusion: Age and number of health problems are the factors that have the greatest influence on work impairment. These findings indicate that the health condition of nurses at community health centers must be considered to improve the overall quality of nursing service.

Probabilistic analysis of anisotropic rock slope with reinforcement measures

  • Zoran Berisavljevic;Dusan Berisavljevic;Milos Marjanovic;Svetlana Melentijevic
    • Geomechanics and Engineering
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    • v.34 no.3
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    • pp.285-301
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    • 2023
  • During the construction of E75 highway through Grdelica gorge in Serbia, a major failure occurred in the zone of reinforced rock slope. Excavation was performed in highly anisotropic Paleozoic schist rock formation. The reinforcement consisted of the two rows of micropile wall with pre-stressed anchors. Forces in anchors were monitored with load cells while benchmarks were installed for superficial displacement measurements. The aim of the study is to investigate possible causes of instability considering different probability distributions of the strength of discontinuities and anchor bond strength by applying different optimization techniques for finding the critical failure surface. Even though the deterministic safety factor value is close to unity, the probability of failure is governed by variability of shear strength of anisotropic planes and optimization method used for locating the critical sliding surface. The Cuckoo search technique produces higher failure probabilities compared to the others. Depending on the assigned statistical distribution of input parameters, various performance functions of the factor of safety are obtained. The probability of failure is insensitive to the variation of bond strength. Different sampling techniques should yield similar results considering that the sufficient number of safety factor evaluations is chosen to achieve converged solution.

Somatotype of Women's Upper Body in their thirties through a Development Figure of the Surface of the Body (체표면 전개도에 의한 30대 여자 상반신의 유형분석)

  • 최은주
    • Journal of the Korean Society of Clothing and Textiles
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    • v.22 no.2
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    • pp.203-214
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    • 1998
  • The purpose of this study is to classify the upper body of women into several kinds of somatotypes, using the method of Surgical Tape and making their shells. The subjects are 53 females 30 to 39 years-old. Fifty-three anthropometric data are measured per shell of bodysurface; six somatotype factors are obtained through principal component analysis and orthogonal rotation by the method of Varimax, Somatotype of women's upper body is achieved by cluster analysis, using the standardized factor score as an independent variable and the FASTCLUS of SAS by Kmeans. The results are as follows: 1. The number of the factors which explain the somatotype is six and those factors comprise 76.12 percent of total variance. Factor 1: related to the size of shape in the front of upper body Factor S: related to the size of shape in the back of upper body Factor 3: related to the type of the upper chest over the chest circumference line Factor 4: related to the length of·the upper body Factor 5: related to the part of the neck Factor 6: related to the type of the lower chest under the chest circumference line 2. Cluster analysis results in classification of upper body into five clusters. Cluster L: the length is the largest and the circumference is small. The part of waist is the largest and widest among surface areas. Cluster 2: Slender body line from chest to waist is characteristic. The length is longer. The part of upper and lower chest is larger among surface areas. Cluster S: the circumference is the smallest and armhole is small. The length and surface area are small. Cluster 4: the circumference and armhole is the largest. The length is the smallest. Cluster 5: the circumference is average and the length is a little long. The body line(silhouette) from chest to waist is curved slightly.

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Classification of Side Somatotype of Upper Lateral Torso Analyzing 3D Body Scan Image of American Females (미국 여성의 3차원 바디 스캔 이미지 분석을 통한 상반신 측면체형 분류)

  • Na, Hyun-Shin
    • Journal of the Korean Society of Costume
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    • v.57 no.4 s.113
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    • pp.9-17
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    • 2007
  • Somatotype is human body shape and physique type which can be classified not only by the size, but also by the shape or posture of the body. Postural variations in the alignment of the back, shoulder, and neck can have an adverse effect on the fit of garments designed to hang from the shoulders. There have been some previous studies about the lateral upper torso by analyzing photographic measurements. In this study, 3D body scan images were used to classify the side somatotype of upper lateral method even though they are major data in the classification of upper torso. This study focused on following objective.; 1) To apply new and developing technology into the apparel industry analyzing 3D body scan images. 2) To classify upper laterla torso using the data through the new improver technology, 3D body scanner. 3) To propose basic materials for well fitted garments for each type of figure. The test subjects for this study were two hundreds nine female aged 19 years and up who were recruited in Cornell university body scan research team. Seventeen Variables(12 angles, 5 lengths) out of 3D body scan data were measured based on these landmarks and applied to analyze. The result of factor analysis indicated that 6 factors were extracted through factor analysis and orthogonal rotation by the method of Varimax and those factors comprise 62.5% of total variance. And the somatotype of upper body is classified into 3 types of figures according to cluster analysis; Bent forward posture, Straight posture, Swayback posture. Future study could be addressed about the somatotype of body by the age group based on the large database with wide variety of age.

Content Analysis of Wormwood Smoke(Ssukjahun) Experiences in Women (여성의 쑥좌훈 경험에 대한 내용분석)

  • Lee, Kwang-Ok;Jang, Sun-Bok;Yoo, Ji-Soo
    • Journal of East-West Nursing Research
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    • v.14 no.1
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    • pp.68-77
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    • 2008
  • Purpose: This Study aims to explore the Wormwood smoke(Ssukjahun) experiences of women and to provide the data to develop Korean traditional nursing intervention for women. Methods: A sample of 15 women aged between 20 to 60 years with Ssukjahun experiences was interviewed and content analysis was used to analyze the data. Results: Six categories and Thirty attributes were derived for Ssukjahun experiences in women. The reason of Ssukjahun is related to illness included vaginitis, insomnia, mental depression, circulation down of hand and feet, repeat abortion, dysmenorrhea, hemorrhoids, disc, rheumatism, and asthma. The place of Ssukjahun was home, oriental hospital and Ssukjahun room. Also method of Ssukjahun included steam methods and burn the wormwood. The time-consuming of Ssukjahun was about 30 minutes. The response and effect in Ssukjahunincluded relax, decreasing rhinitis, weight reduction, feel better, increasing circulation, sleep well, reducing constipation, insomnia, hemorrhoid, back pain, asthma, and dysmenorrhea. The negative effect of Ssukjahun included vesicle, headache, itching sense, generalache, acne, and edema. However, women who did Ssukjahun believed that is the belligerent reaction because it is gone after several times. The preference of Ssukjahun than hospital treatment is related to side effect of medication, temporary method for reducing symptom. Recommends: It is recommended for nurses to understand experience of Ssukjahun in women. If Ssukjahun is to be own nursing intervention, it has to find solutions to encourage positive experiences and overcome negative experiences. Also it recommended research for experience of men.

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Analysis of Chemical Compounds of Gaseous and Particulate Pollutants from the Open Burning of Agricultural HDPE Film Waste

  • Kim, Tae-Han;Choi, Boo-Hun;Kook, Joongjin
    • Journal of People, Plants, and Environment
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    • v.24 no.6
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    • pp.585-593
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    • 2021
  • Background and objective: Illegal open-air incineration, which is criticized as a leading source of air pollutants among agricultural activities, currently requires constant effort and attention. Countries around the world have been undertaking studies on the emission of heavy metal substances in fine dust discharged during the incineration process. A precise analytical method is required to examine the harmful effects of particulate pollutants on the human body. Methods: In order to simulate open-air incineration, the infrastructure needed for incineration tests complying with the United States Environmental Protection Agency (EPA) Method 5G was built, and a large-area analysis was conducted on particulate pollutants through automated scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDS). For the test specimen, high-density polyethylene (HDPE) waste collected by the DangJin Office located in Choongcheongnam-do was used. To increase the identifiability of the analyzed particles, the incineration experiment was conducted in an incinerator three times after dividing the film waste into 200 g specimens. Results: Among the metal particulate matters detected in the HDPE waste incineration test, transition metals included C (20.8-37.1 wt%) and O (33.7-37.9 wt%). As for other chemical matters, the analysis showed that metal particulate matters such as metalloids, alkali metals, alkaline earth metals, and transition metals reacted to C and C-O. Si, a representative metalloid, was detected at 14.8-20.8 wt%, showing the highest weight ratio except for C and O. Conclusion: In this study, the detection of metal chemicals in incinerated particulate matters was effectively confirmed through SEM-EDS. The results of this study verified that HDPE waste adsorbs metal chemicals originating from soil due to its own properties and deterioration, and that when incinerated, it emits particulate matters containing transition metals and other metals that contribute to the excessive production and reduction of reactive oxygen species.

Crack detection in folded plates with back-propagated artificial neural network

  • Oguzhan Das;Can Gonenli;Duygu Bagci Das
    • Steel and Composite Structures
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    • v.46 no.3
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    • pp.319-334
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    • 2023
  • Localizing damages is an essential task to monitor the health of the structures since they may not be able to operate anymore. Among the damage detection techniques, non-destructive methods are considerably more preferred than destructive methods since damage can be located without affecting the structural integrity. However, these methods have several drawbacks in terms of detecting abilities, time consumption, cost, and hardware or software requirements. Employing artificial intelligence techniques could overcome such issues and could provide a powerful damage detection model if the technique is utilized correctly. In this study, the crack localization in flat and folded plate structures has been conducted by employing a Backpropagated Artificial Neural Network (BPANN). For this purpose, cracks with 18 different dimensions in thin, flat, and folded structures having 150, 300, 450, and 600 folding angle have been modeled and subjected to free vibration analysis by employing the Classical Plate Theory with Finite Element Method. A Four-nodded quadrilateral element having six degrees of freedom has been considered to represent those structures mathematically. The first ten natural frequencies have been obtained regarding healthy and cracked structures. To localize the crack, the ratios of the frequencies of the cracked flat and folded structures to those of healthy ones have been taken into account. Those ratios have been given to BPANN as the input variables, while the crack locations have been considered as the output variables. A total of 500 crack locations have been regarded within the dataset obtained from the results of the free vibration analysis. To build the best intelligent model, a feature search has been conducted for BAPNN regarding activation function, the number of hidden layers, and the number of hidden neurons. Regarding the analysis results, it is concluded that the BPANN is able to localize the cracks with an average accuracy of 95.12%.