• Title/Summary/Keyword: Pressure down

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Material structure generation of concrete and its further usage in numerical simulations

  • Husek, Martin;Kala, Jiri
    • Structural Engineering and Mechanics
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    • v.68 no.3
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    • pp.335-344
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    • 2018
  • The execution of an experiment is a complex affair. It includes the preparation of test specimens, the measurement process itself and also the evaluation of the experiment as such. Financial requirements can differ significantly. In contrast, the cost of numerical simulations can be negligible, but what is the credibility of a simulated experiment? Discussions frequently arise concerning the methodology used in simulations, and particularly over the geometric model used. Simplification, rounding or the complete omission of details are frequent reasons for differences that occur between simulation results and the results of executed experiments. However, the creation of a very complex geometry, perhaps all the way down to the resolution of the very structure of the material, can be complicated. The subject of the article is therefore a means of creating the material structure of concrete contained in a test specimen. Because a complex approach is taken right from the very start of the numerical simulation, maximum agreement with experimental results can be achieved. With regard to the automation of the process described, countless material structures can be generated and randomly produced samples simulated in this way. Subsequently, a certain degree of randomness can be observed in the results obtained, e.g., the shape of the failure - just as is the case with experiments. The first part of the article presents a description of a complex approach to the creation of a geometry representing real concrete test specimens. The second part presents a practical application in which the numerical simulation of the compressive testing of concrete is executed using the generated geometry.

Kinematic Comparative Analysis of Long Turns between Experienced and Inexperienced Ski Instructors

  • Jo, Hyun Dai
    • Korean Journal of Applied Biomechanics
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    • v.30 no.1
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    • pp.17-25
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    • 2020
  • Objective: The purpose of this study is to provide a better understanding of long turn mechanism by describing long turns after kinematic analysis and provide skiers and winter sports instructors with data through which they are able to analyze right postures for turns in skiing in a systematic, rational and scientific manner. Method: For this, a mean difference of kinematic variables (the center of gravity (CG) displacement of distance, trajectory, velocity, angle) was verified against a total of 12 skiers (skilled and unskilled, 6 persons each), regarding motions from the up-start to down-end points for long turns. Results: First, concerning the horizontal displacement of CG during a turn in skiing, skilled skiers were positioned on the right side at the upstart and edge-change points at a long turn. There was no difference in anteroposterior and vertical displacements. Second, in terms of CG-trajectory differences, skilled skiers revealed a significant difference during a long turn. Third, regarding skiing velocity, skilled skiers were fast at the edge-change and maximum inclination points in long turns. Fourth, there was no difference in a hip joint in terms of a lower limb joint angle. In a knee joint, a large angle was found at the up-start point among skilled skiers when they made a long turn. Conclusion: In overall, when skilled and unskilled skiers were compared, to make a good turn, it is required to turn according to the radius of turn by reducing weight, concerning the CG displacement. Regarding the CG-trajectory differences, the edge angle should be adjusted via proper inclination angulation. In addition, a skier should be more leaned toward the inside of a turn when they make a long turn. In terms of skiing velocity, it is needed to reduce friction on snow through the edging and pivoting of the radius or turn according to curvature and controlling ski pressure. Regarding a lower limb joint angle, it is important to make an up move by increasing ankle and knee angles instead of keeping the upper body straight during an up motion.

Effects of Electroacupuncture on Immune Function (전기침이 면역증진에 미치는 효과)

  • Kang, Se-Young;Jeong, Eun-Woo;Lee, Sang-Kwan;Sung, Kang-Keyng
    • Journal of Acupuncture Research
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    • v.24 no.6
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    • pp.29-36
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    • 2007
  • Electroacupuncture(EA) is known to affect various autonomic functions such as blood pressure regulation, immune modulation and the improvement of disorders concerning autonomic functions. The aim of the present study was to establish whether EA has an immune-enhancing effect. ICR mice weighing 20 to 25g were divided into four groups: Group I(n=6), blank; Group II(n=6), control; Group III(Zusanli, n=6), low frequency-EA(10Hz of electrical stimulation), and Group IV(Zusanli, n=6), high frequency-EA (100Hz of electrical stimulation). For this study, we investigated expressions of spleen heat shock protein (HSP)70, HSP90 and secretions of cytokines. A Forced Swimming Test(FST) was performed as a model of activity test in mice. After three days of the FST, 10Hz EA($114.8{\pm}7.27s$) and 100Hz EA($147.5{\pm}1.29s$) immobility time significantly decreased compared with the control group($157.2{\pm}1.48s$). After seven days, 10Hz EA($124{\pm}1s$) and 100Hz EA($141{\pm}4.24s$) also significantly decreased immobility time compared with the control group($168{\pm}7.93s$). 10Hz EA and 100Hz EA increased the expression of HSP70 but did not change that of HSP90. 100Hz EA increased secretions of IL-6 and IL-12 compared with the control group however, 10Hz EA failed to change those of IL-6 and IL-12. The present results suggest that EA may be useful for down-regulated immune diseases.

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Analysis of Researches on the Warming Therapy for Surgical Patients (수술 환자에게 적용한 가온요법 연구논문 분석)

  • Jun, Jum-Yi
    • Korean Journal of Adult Nursing
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    • v.22 no.3
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    • pp.260-270
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    • 2010
  • Purpose: The main question is systematic review of the published in Korea and foreign countries on warming therapy for surgical patients. Methods: The researchers searched at Medline, CINAHL, KERIS, Adult Nursing Association, Korean Society of Nursing Science, Korean Academy of fundamentals of Nursing, and National Assembly Library web site for the published on warming therapy for surgical patients from 1980 to 2008. Words for search were operation/surgery, warming, operation/surgery and warming. Studies were included randomized controlled trial, and there were no restrictions regarding operative phase and outcome measures. Results: 36 published researches that met the criteria were mostly published in foreign countries between 2000 and 2008 and focused on surgery with general anesthesia. Sample size ranged from 21 to 60 subjects, age range between 21 and 60 years of age. Thirty different warming therapies were reported, fifty-two different dependent variables. Outcome indicators included active external warming, intra-operative, and body temperature. 'Positive effects' and 'no effects' equaled. The most frequently reported 'positive effects' were body temperature, shivering, and acid-base balance. No effects were more likely to be heart rate, blood pressure, and hemodynamics. Conclusion: Many types of warming therapy, are reported in the literature with little information about the efficacy of each, many different dependant variables were studied. There were no consistent reports as to length of time used for warming procedures. Overall, the effects of warming therapy are inconsistent. And additional research must be down before any particular method of warming can be used with confidence as to its effectiveness. Attention must be made as to the research design, better measurement of the dependent variables. This review may serve as a base.

The Study for Correlation Characteristics on Radial Artery and Floating/sinking Pulse with BMI (BMI에 따른 요골동맥의 혈관특성과 부/침맥과의 상관관계 연구)

  • Lee, Yu-Jung;Lee, Jeon;Lee, Hae-Jung;Kim, Jong-Yeol
    • Korean Journal of Oriental Medicine
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    • v.14 no.3
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    • pp.121-126
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    • 2008
  • Pulse diagnosis refers to the process of diagnosing a patient by feeling an artery on the wrist based on the shape that the pulse take s while the hold-down pressure increase. The styloid process artery on the wrist is usually felt, and the pulse is taken on Chon, Gwan and Cheok using three fingers. This study is to examine the structural difference in the location of pulse diagnosis by measuring and analyzing blood diameter, blood depth, and blood flow velocity of the location of pulse diagnosis by using ultrasonic wave (VOLUSION730 PRO, GE Medical, U.S.A). This study also attempted to grasp whether the characteristics of blood vessels differ depending on Body Mass Index (BMI) and analyzed their correlation with Oriental medical pulse diagnosis. The male subjects without cardiovascular diseases were divided into the normal BMI group, the underweight group and the overweight group and 10 people of each group were measured, Blood depth, blood diameter and blood flow velocity at the location of pulse diagnosis (Chon, Gwan, Cheok) of the wrists of left and right hands were measured and the pulse wave was measured by using pulse diagnosis instrument (3-D Mac, DaeyoMedi, Korea).The results of this study showed that the characteristics of blood vessels differ depending on the degrees of obesity, and the characteristics of floating pulse and sinking pulse of Oriental medical pulses were related to the degrees of obesity. This shows that the characteristics of the blood vessels of subjects and BMI information are the major indicators for diagnosis and are the matters that must always be considered when developing the algorithm of pulse diagnosis.

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A Comparative Experiment on Thermal Stress Failure of Vacuum Glazing applied in Curtain Wall at Spandrel area (커튼월 스팬드럴용 진공유리의 열파손에 대한 비교실험)

  • Kim, Seung-Chul;Yoon, Jong-Ho;Shin, U-Cheol;Ahn, Jung-Hyuk
    • KIEAE Journal
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    • v.16 no.3
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    • pp.121-128
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    • 2016
  • Purpose: The vacuum glazing should constantly retain the gap in vacuum state to maintain high thermal performance. To do so, pillars are used to prevent the glazing from clinging to each other by the atmospheric pressure and therefore surface of the vacuum glazing is consistently affected by residual stress. The vacuum glazing could be applied to curtain wall systems at spandrel area to fulfill a rigorous domestic standard on U-value of the external wall. However, this can lead to high glazing temperature increase by heat concentration at a back panel and finally thermal stress breakage. This study experimentally determined weakness of the vacuum glazing systems on the thermal stress breakage and investigated effect of the residual stress. Method: The experiment first built two scale-down mock-up facilities that replicate the spandrel area in curtain wall, and then installed single low-e glass and vacuum glazing respectively. The two mock-up facilities were exposed to outside to induce the thermal stress breakage. Result: The experiment showed that the temperature occurred the thermal stress breakage was $114.4^{\circ}C$ for the single low-e glass and $118.9^{\circ}C$ for the vacuum glazing respectively. The result also showed the vacuum glazing reached the critical point earlier than the single low-e glass, which means that the vacuum glazing has high potential to occur the thermal shock breakage. In addition, the small temperature difference between two glazing indicates that the residual stress scarcely affects breakage of the vacuum glazing.

Implementation of Marine Optical Sensor System Using A Line-CCD (Line-CCD를 이용한 수중광학 센서 시스템의 구현)

  • Jeong, Ui-Seok;Lee, Dong-Ho;Lee, Kyoung-Woon;Lim, A-Ram;Jeong, Jae-Wook;Park, Jung-Ho
    • Journal of IKEEE
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    • v.14 no.3
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    • pp.244-249
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    • 2010
  • We fabricated optical sensor system that take a measurement particles using a line-CCD in ocean. To measure particles, we used 680nm laser diode which is appropriate. we tested to operate optical system in water tank and ocean. It has performance that detected signal of sensors transfer microprocessor, FPGA as long as move up and down it's motion. The system algorithm also analysis output -pressure, temperature, particle numbers in depth.-For experiment, our particle sensor system has high accuracy counter. therefore, we proposed that a line-CCD is available on optical sensor system in ocean.

Analysis of the Long-term Trend of PM10 Using KZ Filter in Busan, Korea (KZ 필터를 이용한 부산지역 PM10의 장기 추세 분석)

  • Do, Woo-gon;Jung, Woo-Sik
    • Journal of Environmental Science International
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    • v.26 no.2
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    • pp.221-230
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    • 2017
  • To determine the effect of air pollution reduction policies, the long-term trend of air pollutants should be analyzed. Kolmogorov-Zurbenko (KZ) filter is a low-pass filter, produced through repeated iterations of a moving average to separate each variable into its temporal components. The moving average for a KZ(m, p) filter is calculated by a filter with window length m and p iterations. The output of the first pass subsequently becomes the input for the next pass. Adjusting the window length and the number of iterations makes it possible to control the filtering of different scales of motion. To break down the daily mean $PM_{10}$ into individual time components, we assume that the original time series comprises of a long-term trend, seasonal variation, and a short-term component. The short-term component is attributable to weather and short-term fluctuations in precursor emissions, while the seasonal component is a result of changes in the solar angle. The long-term trend results from changes in overall emissions, pollutant transport, climate, policy and/or economics. The long-term trend of the daily mean $PM_{10}$ decreased sharply from $59.6ug/m^3$ in 2002 to $44.6ug/m^3$ in 2015. This suggests that there was a long-term downward trend since 2005. The difference between the unadjusted and meteorologically adjusted long-term $PM_{10}$ is small. Therefore, we can conclude that $PM_{10}$ is unaffected by the meteorological variables (total insolation, daily mean temperature, daily mean relative humidity, daily mean wind speed, and daily mean local atmospheric pressure) in Busan.

Case of making maxillary palatal augmentation complete denture for patient with dysphagia after partial glossectomy (부분 혀 절제술로 인해 연하 장애가 있는 환자에서 상악 구개 증대 총의치 제작 증례)

  • Kim, Hyung-Seok;Park, Ji-Young;Yim, Sun-Young;Heo, Yu-Ri;Son, Mee-Kyoung
    • Journal of Dental Rehabilitation and Applied Science
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    • v.34 no.3
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    • pp.239-245
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    • 2018
  • If complication arises after glossectomy which leads to trouble in forming food bolus or transfer of the food, it is possible that either food bolus may block the airway or dysphagia may occur as the food bolus goes down into the airway. To solve the issue, palatal augmentation prosthesis could be used. In this case, the patient with an oral cancer is having difficulties swallowing food after glossectomy. Through taking impressions of polishing surface of his denture referring his tongue movement, the complete denture for the upper jaw was created using the concept of palatal augmentation prosthesis. This new upper denture increases the palatal-tongue contact pressure, allowing the patient to perform better swallowing and better pronunciation.

Improvement of Soil Strength by Injection of Water-Glass Chemical Grout (물유리계 주입재(注入材)를 주로 한 지반강도증대(地盤強度增大))

  • Jin, Byung Ik;Chun, Byung Sik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.4 no.2
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    • pp.89-99
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    • 1984
  • Engineering properties of soils is studied by permeating injection of water-glass chemical grout by use of a large sized grouting equipment of 1.5 shot system. Furthermore, the effectiveness of chemical groutinig by taking water-glass chemical grout combined with portland-cement for the purpose of improving the soil strength is confirmed. Relationships between main factors which cause the effectiveness of chemical grouting are described, and the factors are velocity and temperature of flowing water; grain size distribution and density of soils; density, viscosity, gel time and volume of grouts; injection pressure and grouting process. Improvement of the effectiveness of chemical grouting in flowing water by preventing the dilution and flowing down of grouts is investigated. Moreover, local shear failures and upheaval phenomena of ground are also investigated by field measurement.

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