• Title/Summary/Keyword: Time and Motion Studies

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Effects of curvature radius on vulnerability of curved bridges subjected to near and far-field strong ground motions

  • Naseri, Ali;Roshan, Alireza MirzaGoltabar;Pahlavan, Hossein;Amiri, Gholamreza Ghodrati
    • Structural Monitoring and Maintenance
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    • v.7 no.4
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    • pp.367-392
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    • 2020
  • The specific characteristics of near-field earthquake records can lead to different dynamic responses of bridges compared to far-field records. However, the effect of near-field strong ground motion has often been neglected in the seismic performance assessment of the bridges. Furthermore, damage to horizontally curved multi-frame RC box-girder bridges in the past earthquakes has intensified the potential of seismic vulnerability of these structures due to their distinctive dynamic behavior. Based on the nonlinear time history analyses in OpenSEES, this article, assesses the effects of near-field versus far-field earthquakes on the seismic performance of horizontally curved multi-frame RC box-girder bridges by accounting the vertical component of the earthquake records. Analytical seismic fragility curves have been derived thru considering uncertainties in the earthquake records, material and geometric properties of bridges. The findings indicate that near-field effects reasonably increase the seismic vulnerability in this bridge sub-class. The results pave the way for future regional risk assessments regarding the importance of either including or excluding near-field effects on the seismic performance of horizontally curved bridges.

A Study on the Aesthetic Characteristics of the Digital Rotoscoping Images in Jonas Odell's Animations (요나스 오델(Jonas Odell)의 작품 세계에 나타난 디지털 로토스코핑 이미지의 특성)

  • Kim, Young-Ok
    • Cartoon and Animation Studies
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    • s.39
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    • pp.111-132
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    • 2015
  • Although Rotoscoping technique has been used for a long time to mimic the natural and smooth motion since the early 20th century, its artistic value was devalued as tricks because it traces the already recorded images. But the fact that the rotoscoping images can cross the boundaries between animation and live action in an infinite integral freedom in the digital era became rather expansive new aesthetic possibilities of representation of the reality. In addition, Jonas Odell's animations such as (2010), (2008), (2006) are good example to prove that the rotoscoping images also can serve as means to enhance its narrative. This study is to analyze how rotoscoping images act as a unique role in relation with the narrative based on the said person's real stories and realistic images. I argue that his animated films constantly contain these three characteristics -Images to mediate Auditory sensitivity as a record of inner metaphysical reality, anonymous images to represent a specific existential character, and images that act as physical representation that holds the physical space/time and related memory. This reveals that rotoscoping images in this digital era went beyond reproduction for natural movements or special type of style. It rather suggests new layers of experience, and acquires new value in animation. I hope that this study could serve as a foundation to rediscover and re-position the value of rotoscoping images as well as good opportunity to introduce very talented swedish animation artist who already received global attention with his unique philosophical and aesthetic style.

Dynamic soil-structure interaction studies on 275m tall industrial chimney with openings

  • Jayalekshmi, B.R.;Thomas, Ansu;Shivashankar, R.
    • Earthquakes and Structures
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    • v.7 no.2
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    • pp.233-250
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    • 2014
  • In this paper, a three dimensional soil-structure interaction (SSI) is numerically simulated using finite element method in order to analyse the foundation moments in annular raft of tall slender chimney structures incorporating the effect of openings in the structure and the effect of soil flexibility, when the structure-soil system is subjected to El Centro (1940) ground motion in time domain. The transient dynamic analysis is carried out using LS-DYNA software. The linear ground response analysis program ProShake has been adopted for obtaining the ground level excitation for different soil conditions, given the rock level excitation. The radial and tangential bending moments of annular raft foundation obtained from this SSI analysis have been compared with those obtained from conventional method according to the Indian standard code of practice, IS 11089:1984. It is observed that tangential and radial moments increase with the increase in flexibility of soil. The analysis results show that the natural frequency of chimney decreases with increase in supporting soil flexibility. Structural responses increase when the openings in the structure are also considered. The purpose of this paper is to propose the need for an accurate evaluation of the soilstructure interaction forces which govern the structural response.

A Study of a Dike Design Considering a Leakage Velocity at an Opening Hole in Case of a Leakage Accident (누출사고 시 저장탱크 위험물 누출속도를 고려한 방유제 설계에 관한 연구)

  • Lee, Jae Yeol;Kim, Dong Hyun;Ban, Soon Hee;Lee, Chang Jun
    • Journal of the Korean Society of Safety
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    • v.32 no.6
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    • pp.40-45
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    • 2017
  • Chemical accidents generated during maintenance, repair, and normal operation, such as dispersion, fire, and explosions, can cause massive losses like a 2012 hydro fluorine leak in Gumi, South Korea. Since this accident, many researches have studied physical mitigation systems. However, due to many difficulties including potential costs and lack time, it is really hard for many companies to install mitigation systems without prior knowledge. Thus, the efficacy of mitigation system should be evaluated. This study assesses a dike design considering the fluid velocity at an open hole when a leakage accident occurs. It is assumed that leakage materials follow a free fall motion. Throughout case studies, a current KOSHA guide for a dike design was evaluated and new guidelines handling various conditions were proposed.

Passive Suppression of Nonlinear Panel Flutter Using Piezoelectric Materials with Resonant Circuit

  • Moon, Seong-Hwan;Yun, Chul-Yong;Kim, Seung-Jo
    • Journal of Mechanical Science and Technology
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    • v.16 no.1
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    • pp.1-12
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    • 2002
  • In this study, a passive suppression scheme for nonlinear flutter problem of composite panel, which is believed to be more reliable than the active control methods in practical operations, is proposed. This scheme utilizes a piezoelectric inductor-resistor series shunt circuit. The finite element equations of motion for an electromechanically coupled system is derived by applying the Hamilton\\`s principle. The aerodynamic theory adopted for the present study is based on the quasi-steady piston theory, and von-barman nonlinear strain-displacement relation is also applied. The passive suppression results for nonlinear panel flutter are obtained in the time domain using the Newmark-$\beta$ method. To achieve the best damping effect, optimal shape and location of fille piezoceramic (PZT) patches are determined by using genetic algorithms. The effects of passive suppression are investigated by employing in turn one shunt circuit and two independent shunt circuits. Feasibility studies show that two independent inductor-resistor shunt circuits suppresses flutter more effectively than a single shunt circuit. The results clearly demonstrate that the passive damping scheme that uses piezoelectric shunt circuit can effectively attenuate the flutter.

Vibration control of an SDOF structure using semi-active tuned mass damner (준능동 TMD를 이용한 단자유도 구조물의 진동제어)

  • Kim, Hyun-Su;Lee, Dong-Guen
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.424-431
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    • 2006
  • Many types of tuned mass dampers (TMDs), such as active TMDs, multiple TMDs, hybrid TMDs etc., have been studied to effectively reduce the dynamic responses of a structure subjected to various types of dynamic loads. In this study, we replace a passive damper by a semi-active tuned mass damper to improve the control performance of conventional TMDs (STMD). An idealized variable damping device is used as semi-active dampers. These semi-active dampers can change the properties of TMDs in real time based on the dynamic responses of a structure. The control performance of STMD is investigated with respect to various types of excitation by numerical simulation. Groundhook control algorithm is used to appropriately modulate the damping force of semi-active dampers. The control effectiveness between STMD and a conventional passive TMD, both under harmonic and random excitations, is evaluated and compared for a single-degree-of-freedom (SDOF) structure. Excitations are applied to the structure as a dynamic force and ground motion, respectively. The numerical studies showed that the control effectiveness of STMD is significantly superior to that of the passive TMD, regardless of the type of excitations.

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A Study on the life of Yoon Cho Chang(尹草窓) and Cho-Chang-Kyeul(草窓訣) (윤초창(尹草窓)의 생애(生涯)와 초창결(草窓訣)에 관(關) 연구(硏究))

  • Kim, Joon Tae;Yoon, Chang Yeul
    • Journal of Korean Medical classics
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    • v.6
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    • pp.189-227
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    • 1993
  • I have studied life of Yoon-Dong-Li(尹東里), who applied Un-Ki(運氣) theory to medicine during Suk-Jong(肅宗) to Joong-Jo(正祖) in Yi-Dynasty and also studied his existing writings named ${\ll}$Cho-Chang-kyeol${\gg}$ (草窓訣). The referenced original work prints were based on 1980's print of Chung-Ku oriental medical society and National Central Library and The academy a korean studies possessed print. Studied with these books, I have concluded as follows. 1. Yoon-Dong-Li(尹東里) courtesy name is Ja-Mi(子美), pen name is Cho-Chang(草窓). He was born in 1705, Suk-Jong(肅宗) 31yrs, and died in 1784, Jeong-Jo(正祖) 8yrs in Yi-Dynasty. He had lineage of third-generationed-doctor and learned medicine from his uncle, Yoon-Woo-Kyo(尹雨敎). His father Yoon-Yi-Kyo(尹이敎) gaved him second influence. 2. Confucianal physician in Ming Dynasty You-Bu(劉溥) respected Ju-Ryeom-Kye(周溓溪), confucianist in Song-Dynasty and You-Bu(劉溥) does not removed grass in front of window (because in chinese, Cho-Charig(草窓) means grass in front of window), and named himself Cho-Chang(草窓). Yoon-Dong-Li(尹東里) followed this suit so called himself Cho-Chang (草窓). 3. The main contents of ${\ll}$Cho-Chang-Kyeol${\gg}$ (草窓訣), (運氣衍論) was written in 1725, when Yoon-Dong-Li(尹東里) was 21yrs old and printed in 1736. The other part of ${\ll}$Cho-Chang-Kyeol${\gg}$ (草窓訣), (用藥篇) was written in 1746. These two parts were not written in the satre time. The (運氣衍論) was written llyears earlier than (用藥). Two parts were combined another day and named (草窓訣). 4. Existing ${\ll}$Cho-Chang-Kyeol${\gg}$ (草窓訣) is transcribed printing with the con tent of "Five elements motion and the six kind of natural factors theory" (五運六氣設). Each edition is generally similar in content, but also has different points each other so naw we hardly finds a complete set of works. 5. ${\ll}$Cho-Chang-Kyeol${\gg}$ (草窓訣) is a first technical book which treats of Un-Ki(運氣) theory in korea. 6. The contents of (運氣衍論) of ${\ll}$Cho-Chang-Kyeol${\gg}$ (草窓訣) is mechanism of diease according to excess and insuffciency of five elements motion and six kinds of nalural faclors.and symploms and priscriptions, includes variated priscriptions. 7. Two parts in (運氣衍論) of ${\ll}$Cho-Chang-Kyeol${\gg}$ (草窓訣), 'Sang-tong' (相通) and 'Kak-Tong' (各通), threats of mochanisim of the disease according to five elements. with the principle of inter-promoting and inter-acting, in the change of ten heavenly stems and five elements motion. 8. In the (用藥篇) of ${\ll}$Cho-Chang-Kyeol${\gg}$ (草窓訣) describes priscription for clinical application according to Un-Ki(運氣) and also records about misuse of medicine. 9. In the ${\ll}$Cho-Chang-Kyeol${\gg}$ (草窓訣), most of priscription are common using one, which also found in ${\ll}$Dong-$\breve{U}$i-Bo-Garm${\gg}$ (東醫寶鑑) and there are few of priscriptions hy Yoon-Dong-Li(尹東里).

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An Experimental Study for the Design of Household-Storage Facilities (부엌 수납장 설계 기준 설정을 위한 기초적 연구)

  • 최재순
    • Journal of the Korean Home Economics Association
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    • v.20 no.4
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    • pp.155-168
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    • 1982
  • What is attempted here is to find out an optimum method for the design of physical environments that could save human energy expenditures and safely perform household duties. There are, if any, very little amount of research done in this area. This is particulary so when the work relates to the designing of household storage facilities in the light of the energy metabolism of human body. The first step to this study, therefore, is to find out the ways by which we can determine the energy metabolism of human body accurately. To measure the volume and the concentration of human respiration continuously and automatically, a new apparatus is selected here. This includes the recording system with the Wright Respirometer and the Expired Gas Analyzer as well as the computer system to multiply volume by concentration of human respiration and to integrate them for a given time. Then, the author experimented on the reliability of this apparatus and came to the conclusion that this apparatus satisfied our need to research the energy metabolism of human body. Next, the general plan and procedures to experiment with this apparatus have been determined as follows: 1) subjects are three young and sound females. Their physical characteristics are shown in Table 1 and most approximates the standard characteristics of Japanese females, 2) height of open shelves is selected in such away as to correspond to the respective height of each subject(see Table 2), 3) utensils to be stored are box shaped object, which weight is 0.5kg, 1.0kg, 2.0kg or 3.0kg, 4) working motions are given while one or two hands as to place utensil on each shelf from the standard working board, 85 cm in height and then to place back it on the board from the shelf and repeated in constant velocity as 10 times per a minute, 5) each posture of motion is chosen by each subject in free, 6) procedures of measurement of human energy metabolism ard shown at(6), 1, Section 3 as specific methods for using this apparatus. Findings of this study are as follows: 1. Human energy expenditures for storing utensils on shelves by each subject are shown in quantity more accurately than in any other studies, under varying conditions about height of shelves, load of utensils and working motion with one hand and two hands (see Fig. 8~13 and Table 3). 2. Experimental formulae of human energy expenditure for that work are shown as formula (8), (9) and (10), to generalize results of 1. and to apply those for working motion under given conditions. 3. As results of analysis on gained data, we are able to show the standard model of human energy expenditures for storing untensils on shelves by the standard Japanese female (see Table 7 and Fig. 14).

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The Types of Secondary School Students' Preconceptions on the Motion of the Earth and the Moon (계통도를 이용한 중.고등학생의 지구와 달의 운동에 관한 개념 유형 연구)

  • Woo, Jong-Ok;Lee, Hang-Ro;Min, Jun-Gyu
    • Journal of The Korean Association For Science Education
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    • v.15 no.4
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    • pp.379-393
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    • 1995
  • In spite of school science learning, the students' conceptions have not been changed easily. Therefore, to make students overcome their non scientific conceptions has been an important issue in science education. The purpose of this study was to identify the conceptions of students and teachers on the motion of the earth and the moon. The instrument was developed for estimating students' understandings of the concepts related to the motion of the earth and the moon. The validity of the instrument was examined by the specialists in Science Educator and Astronomer. At the same time, the two field trials had been executed, and the items were modified. Also, it consists of 12 items including 9 two-tier multiple choice items and 3 multiple choice items. The population of this study consists of 250 eighth-, 299 tenth-, 292 eleventh-grade students, 134 science teachers in secondary school. SPSS/PC+ was adopted for the statistical analysis. The type of misconceptions possessed students were as follows: 1) At 12:00 noon, the sun is directly overhead. 2) First quarter moon is a half of overall surface of the moon. 3) Air don't rotate with the earth surface because it keeps apart from the earth surface. 4) Summer is warmer than winter, because the earth is nearer from the sun in summer. 5) Whenever season is changed, the direction of rotation axis of the earth is changed. 6) The moon is the brightest at the position of new moon, because the distance between the moon and the sun is the shortest and the moon is received strongest sunlight. 7) The moon is not seen at the position of real full moon, because it is covered with shadow of the earth. 8) When the moon is not seen in the earth, sunlight is not reached at the moon. The major findings were as follows : 1) The middle school students had more misconceptions than those of high school students. And female students had more misconceptions than those of male ones. 2) The rate of correct answer and the type of conception in the tenth grade students were very similar with eleventh grade students. 3) The higher cognitive level, the better development of scientific conception and the less misconception. Also, the correlation coefficient between scientific conception score and GALT score was 0.57. 4) The students in scientific part had higher the rate of correct answer than those of students in human part and the former had less misconception than the latter. 5) The rate of correct answer about model and figure items was lower than descriptive ones, because they did not understand about figures itselves. These types of misconceptions will be used for science instruction and studies of other conceptions need.

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One Case of Subluxation of the Head of the Radius treated with Carthami Flos Herbal-Acupuncture(CF) (홍화약침(紅花藥鍼)을 사용한 요골두 아탈구 환자 치험 1례)

  • Lee, Yoon-kyoung;Lim, Seong-chul;Jung, Tae-young;Seo, Jung-chul;Han, Sang-won
    • Journal of Acupuncture Research
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    • v.21 no.6
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    • pp.291-298
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    • 2004
  • Objective : This study was designed to investigate the effect of Carthami Flos Herbal-Acupuncture(CF) on Subluxation of the Head of the Radius. Methods : CF was administered one time per 2days. The following points were selected : TE10(天井), LI11(曲池), LI10(手三里). After CF administration conventional body-acupuncture was performed at the same points. We evaluated the patient through Visual Analogue Scale(VAS) and Elbow Range of Motion(ROM). Results : After 6 times of treatment, the patient showed that clinical symptoms was disappeared, VAS changed from 10 to 1 and there was no limitation of ROM. Conclusions : According to the results, CF and early Exercising may have rapid effects on the Subluxation of the Head of the Radius. But further studies are required to prove the effect of CF on Subluxation of the Head of the Radius.

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