• Title/Summary/Keyword: cross sectional

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Evaluation of Utilization through Various Accuracy Analysis of Drone Photogrammetry (드론사진측량의 다양한 정확도 분석을 통한 활용성 평가)

  • Doo-Pyo Kim;Hye-Won Choi;Jae-Ha Kwak
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.1
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    • pp.121-131
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    • 2023
  • Although the utilization of drone photogrammetry that can generate spatial information using ultra-high-resolution images is increasing in the civil engineering and construction fields, analysis of areas that can be used is insufficient. Therefore, this study attempted to determine how far drone photogrammetry can be used in the civil engineering and construction fields by applying a detailed analysis method. The status map and cross-sectional map were actually vectorized using drone photogrammetry outcomes, compared and analyzed with the results acquired in the field, and the qualitative aspects of traffic safety facilities were analyzed to determine their usability. As a result, the accuracy of the plane position using drone photogrammetry was reliable, but the height accuracy was difficult to trust. Accordingly, although there is a possibility of preparing a status map, the use of it in areas requiring high accuracy such as cross-sectional plans was limited, and it is believed that it can be used in the construction management field where qualitative analysis is conducted.

THE VALIDITY OF HEALTH ASSESSMENTS: RESOLVING SOME RECENT DIFFERENCES

  • Hyland Michael E.
    • 대한예방의학회:학술대회논문집
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    • 1994.02b
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    • pp.137-141
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    • 1994
  • The purpose of this paper is to examine what is meant by a ralid measure of health. Guyatt, Kirshner and Jaeschke propose that health tests should be designed so as to have one of several kinds of validity: 'longitudinal construct validity' for those which are used for longitudinal research designs, and 'cross-sectional construct validity' for those which are used for cross-sectional designs. Williams and Naylor argue that this approach to test classification and validation confuses what a test purports to measure with the purpose for which it is used, and that some tests have multiple uses. A review of the meanings of validity in the psychologica test literature shows that both sets of authors use the term validity in an idiosyncratic way. Although the use of a test (evaluated by content validity) should not be conflated with whether the test actually measures a specified construct (evaluated by construct validity);' if health is actually made up of several constructs (as suggested in Hyland's interactional model) then there may be an association between types of construct and types of purpose. Evidence is reviewed that people make several, independent judgements about their health: cognitive perceptions of health problems are likely to be more sensitive to change in a longitudinal research design. whereas emotional evaluations of health provide less bias in cross-sectional designs. Thus. a classification of health measures in terms of the purpose of the test may parallel a classification in terms of what tests purport to measure.

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Prevalence of chronic pain and contributing factors: a cross-sectional population-based study among 2,379 Iranian adolescents

  • Maryam Shaygan;Azita Jaberi;Marziehsadat Razavizadegan;Zainab Shayegan
    • The Korean Journal of Pain
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    • v.36 no.2
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    • pp.230-241
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    • 2023
  • Background: This study aimed to determine the prevalence of chronic pain and its contributing factors among teenagers aged 12-21 years in Shiraz, Iran. Methods: This cross-sectional study was conducted on adolescents aged 12-21 years. Demographic variables of the adolescents and their parents as well as the pain characteristics were assessed. Descriptive statistics, multinomial logistic regression, and regression models were used to describe the characteristics of the pain and its predictive factors. Results: The prevalence of chronic pain was 23.7%. The results revealed no significant difference between the male and female participants regarding the pain characteristics, except for the home medications used for pain relief. The results of a chi-square test showed that the mother's pain, education, and occupation, and the father's education were associated significantly with chronic pain in adolescents (P < 0.05). Multinomial logistic regression also showed the mother's history of pain played a significant role in the incidence of adolescents' chronic pain. Conclusions: The prevalence of chronic pain was relatively high in these adolescents. The results also provided basic and essential information about the contributing factors in this area. However, consideration of factors such as anxiety, depression, school problems, sleep, and physical activity are suggested in future longitudinal studies.

Development of Cross-sectional Information Conversion System from STL file for Stereolithography (Stereolithography를 위한 STL파일로부터 단면정보 변환시스템의 개발)

  • Choi, Hong-Tae;Kim, Jun-An;Lee, Seok-Hee;Paik, In-Hwan
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.11
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    • pp.140-147
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    • 1995
  • This paper deals with conversion from the STL file to the Slice to the Slice cross-sectional information for Stereolithography. The STL file is widely used for Stereolithography, but it is very difficult to convert STL file into Slice file directly. Because it consists of an ordered list of triangular net without any topological information other than the orientation of each facet. So, The system is accomplished by data flow through several intermediate stages such as Reference. SL1. .SL2L. .SL3. and .SLC file. The data processing is performed in 5 steps: 1) Create a Reference file including common information. 2) Modify STL file within the effective range of SL machine. 3) Calculate a point of intersection between plane equation and line equation. 4) Sort z values in ascending order using quick sort algorithm. 5) Search the adjacent points and formulate a closed loop usingsingly linked linear list. The system is developed by using Borland C++ 3.1 compiler in the environment of Pentium PC, and verified to be satisfactory by making some prototypes of electric household appliances.

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Development and cross-sectional morphology of the recurrent laryngeal nerves in human fetuses

  • Maria Cecilia Baratela;William Paganini Mayer;Josemberg da Silva Baptista
    • Anatomy and Cell Biology
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    • v.57 no.3
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    • pp.392-399
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    • 2024
  • The recurrent laryngeal nerve is a bilateral branch of the vagus nerve that is mainly associated with the motor innervation of the intrinsic muscles of the larynx. Despite its bilateral distribution, the right and left recurrent laryngeal nerves display unequal length due to embryological processes related to the development of the aortic arches. This length asymmetry leads to theories about morphological compensations to provide symmetrical functions to the intrinsic muscles of the larynx. In this study we investigated the developmental and cross-sectional morphometrics of the recurrent laryngeal nerves in human fetuses. Fifteen stillbirth fetuses donated to anatomical and medical research were used for investigation. Fetuses had intrauterine age ranging from 30 to 40 weeks estimated by biometry methods. Specialized anatomical dissection of the visceral block of the neck was performed to prepare histological samples of the recurrent laryngeal nerves in its point of contact with the larynx, and morpho-quantitative techniques were applied to evaluate the epineurium and perineural space of the recurrent laryngeal nerves. No statistical difference in the cross-sectional morphology of the epineurium and perineural space between right and left recurrent laryngeal nerves intra-individually was confirmed, however, we found evidence that these structures are under greater development in the left recurrent laryngeal nerve during 30 to 40 weeks of intrauterine life. Our data suggest that the nerves are under morphological development that possibly set the stage for accommodation of larger diameter and myelinization of the left recurrent laryngeal nerve during post-natal life.

General Worker's Sleep Disturbances and the Degree of Cold-Heat Symptoms: a national cross-sectional survey

  • Min Kyung Hyun
    • Journal of Pharmacopuncture
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    • v.27 no.3
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    • pp.199-210
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    • 2024
  • Objectives: Few studies have examined the impact of healthy sleep among general workers on individuals and society. Therefore, the status and risk factors of sleep disturbances among general workers were investigated. In addition, this study assessed the degree to which cold and heat symptoms are associated with sleep disturbances. Methods: A nationwide cross-sectional study was conducted through an online questionnaire focused on sleep disturbances of the general public in 2021. The degree of cold-heat pattern Identification (CHPI) of the general public was also surveyed. Descriptive statistics and multivariate logistic regression were used to derive the study results. Results: Data from 2,822 workers out of 3,900 valid questionnaires were analyzed. Approximately half of the respondents (49.93%) had sleep disturbances. Among the types of work, self-employed, two-shift work, and working more than 53 hours were associated with sleep disturbances. Sleep disturbances were positively associated with six cold and heat symptoms: three cold symptoms (coldness of the abdomen, coldness of body, and pale face) and three heat symptoms (body feverishness, feverishness of the limbs, and drinking cold water). Conclusion: Customized policies to maintain healthy work are needed for self-employed work, two-shift work, and long working hours, which are risk factors for workers' sleep disturbances. In addition, medical personnel can effectively diagnose and treat sleep disturbances considering the worker's cold and heat symptoms.

Development of Drift Design Method Considering Characteristics of Member Forces (부재력 특성을 고려한 변위조절설계법 개발)

  • 서지현;박효선
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.123-129
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    • 2003
  • Drift design using resizing techniques can be a very practical method in drift design of high-rise buildings since it cannot require sensitivity analysis and structural re-analysis. Resizing techniques has used the cross sectional areas as design variable and supposed that displacement participation factors are inversely proportional to structural weights. Efficiency of resizing techniques based on displacement participation factors may depend on proper selection of sectional properties as design variables. In this study, two different drift design methods with the different sectional properties as design variables are presented and applied to a 20-story structure.

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Free vibrations of circular arches with variable cross-section

  • Wilson, James F.;Lee, Byoung Koo;Oh, Sang Jin
    • Structural Engineering and Mechanics
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    • v.2 no.4
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    • pp.345-357
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    • 1994
  • The differential equations governing free, in-plane vibrations of linearly elastic circular arches with variable cross-sections are derived and solve numerically for quadratic arches with three types of rectangular cross sections. Frequencies, mode shapes, cross-sectional load distributions, and the effects of rotatory inertia on frequencies are reported. Experimental measurements of frequencies and their corresponding mode shapes agree closely with those predicted by theory. The numerical methods presented here for computing frequencies and mode shapes are efficient and reliable.

A Short-Term Longitudinal Study on Parental Bonding & Participant Roles in Bullying Situations : Focused on Children's Gender (아동이 지각한 부모의 양육행동과 또래 괴롭힘에 관한 단기종단연구 : 아동의 성을 중심으로)

  • Sim, Hee-Og
    • Korean Journal of Child Studies
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    • v.31 no.1
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    • pp.1-17
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    • 2010
  • This study explored the differences in gender, developmental period and parents in terms of parenting, the cross-sectional and longitudinal relationships in parenting by gender, and the cross-sectional and longitudinal relationships between participant roles in bullying situations and parenting by gender. The subjects were 498 4-5th grade children and the instruments utilized in this study were the Parental Bonding Instrument (Bowers, Smith, & Binney, 1994) and the Participant Roles Scale (Sutton & Smith, 1999). The subjects were contacted again one year after the first contact. Results showed that the relationships between parents were longitudinally quite stable. Girls whose fathers had higher levels of accurate monitoring were more likely to be defenders cross-sectionally. Girls whose parents had more accurate monitoring were less likely to be victims longitudinally. The results underscore the importance of examining both gender and participant roles in bullying situations.

The effect of air-shafts on reducing the pressure fluctuations in the tunnel with small cross sectional area on conventional line (소단면 기존 철도터널에서 통풍공 개수에 따른 터널내 풍압변동 저감효과에 대한 연구)

  • 김동현;강부병;이재환;신민호;이성욱
    • Proceedings of the KSR Conference
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    • 2000.11a
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    • pp.382-389
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    • 2000
  • The purpose of present study is to investigate for reducing pressure fluctuations in tile case of installing tile air-shafts on the side wall of the tunnel with small cross-sectional area on conventional line. Experiments were performed with a 1/61-scale moving model rig for the tunnel of 0.764km length in the condition of tunnel cross-section area of 28 ㎡ According to the results, the maximum pressure fluctuation is reduced by 45% for 19 air-shafts. This results have the speed-up effects of about 33.4km/h for the train running in tunnel.

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