• Title/Summary/Keyword: Branch History

Search Result 210, Processing Time 0.021 seconds

Parametric study on dynamic behavior of rectangular concrete storage tanks

  • Yazdanian, Mohsen;Fu, Feng
    • Coupled systems mechanics
    • /
    • v.6 no.2
    • /
    • pp.189-206
    • /
    • 2017
  • Tanks are used to store a wide variety of liquids such as oil, gasoline and water. It is reported that, a large number of tanks have been damaged during severe earthquakes. Therefore, understanding their behavior under earthquake is an important subject for structural engineers. In this paper, a comprehensive study is presented on dynamic response of tanks. A parametric study has been completed on the rectangular storage tanks with aid of finite element method (FEM). Various parameters are investigated, such as; liquid height, density and earthquake with different peak ground acceleration (PGA). When investigating these parameters, modal and time history method is used. Six different earthquake records are used for time history analysis. The analysis results show that when the PGA increases by 10.7 times, the maximum displacements, stress, sloshing and base shear increase by 11.4, 22.6, 5.46 and 17.8 times, respectively and when the liquid height increases by two times, the absolute maximum values of stress, displacements, base shear and sloshing increase 1.65, 2.04, 2.05 and 1.34. Furthermore, values of sloshing increase with decrease in density.

A prediction model of low back pain risk: a population based cohort study in Korea

  • Mukasa, David;Sung, Joohon
    • The Korean Journal of Pain
    • /
    • v.33 no.2
    • /
    • pp.153-165
    • /
    • 2020
  • Background: Well-validated risk prediction models help to identify individuals at high risk of diseases and suggest preventive measures. A recent systematic review reported lack of validated prediction models for low back pain (LBP). We aimed to develop prediction models to estimate the 8-year risk of developing LBP and its recurrence. Methods: A population based prospective cohort study using data from 435,968 participants in the National Health Insurance Service-National Sample Cohort enrolled from 2002 to 2010. We used Cox proportional hazards models. Results: During median follow-up period of 8.4 years, there were 143,396 (32.9%) first onset LBP cases. The prediction model of first onset consisted of age, sex, income grade, alcohol consumption, physical exercise, body mass index (BMI), total cholesterol, blood pressure, and medical history of diseases. The model of 5-year recurrence risk was comprised of age, sex, income grade, BMI, length of prescription, and medical history of diseases. The Harrell's C-statistic was 0.812 (95% confidence interval [CI], 0.804-0.820) and 0.916 (95% CI, 0.907-0.924) in validation cohorts of LBP onset and recurrence models, respectively. Age, disc degeneration, and sex conferred the highest risk points for onset, whereas age, spondylolisthesis, and disc degeneration conferred the highest risk for recurrence. Conclusions: LBP risk prediction models and simplified risk scores have been developed and validated using data from general medical practice. This study also offers an opportunity for external validation and updating of the models by incorporating other risk predictors in other settings, especially in this era of precision medicine.

A Study on the Association of Samcho-gyeong(Triple Energizer Meridian) and the Lower Branch of Meridian system (삼초경(三焦經)의 하부 경맥 연관성에 대한 고찰)

  • Kim, Do-Hoon
    • Korean Journal of Acupuncture
    • /
    • v.25 no.4
    • /
    • pp.1-15
    • /
    • 2008
  • Objectives : This study is designed to investigate the association between Samcho-gyeong(TE) and the lower branch of Meridian system. Methods : The base of the study was established by searching for the historic conception of Samcho. Thereafter the meaning of lower correlation was considered and the property of lower part of Samcho Meridian system studied. Results : Samcho is a kind of Yug-Bu(Six hollow viscera, 六腑). It is a functional internal organ, which has been continuously controversial in history. It covers wide range of the internal organs and plays various kinds of roles. Samcho and Simpo lack in interrelation of obverse and reverse. The conception of Sanghap(Upper correlation, 上合) in Naegyeong supplements the deficiency. To establish the conception of Sanghap between Yug-Bu and Hand meridians, there should be established the conception of Hahap(Lower correlation, 下合) between Yug-Bu and foot meridians for treating lower parts. The existence of Hahaphyeol(Lower confluent points, 下合穴) reveals that there were a lot of limits in treating JungHa-cho(Middle and Lower energizers, 中下焦) diseases only with the acupoints of the Hand meridians. Jogsamcho(Triple energizer of foot, 足三焦) meridian written in Taeso(太素), corresponds to the lower leg, and it is believed that it engages in treating diseases in the trunk of the body and Hacho(Lower energizer, 下焦). Conclusions : Therefore, it is believed that the lower part of meridian of Samcho can deal with the symptoms of lower back pain, leg pain, bladder disease, and so on. This study is meaningful in that it expands the range of treatment in acupoints of the regular meridians.

  • PDF

Surgical Treatment of an Aneurysm on a Branch of the Subclavian Artery, and the Mass Presented as a Neck Mass - A case report - (목 부위 종괴로 발현된 우측 쇄골하 동맥 분지에 발생한 동맥류의 수술적 치험 - 1예 보고 -)

  • Lee, Woo-Surng;Kim, Yo-Han;Chee, Hyun-Keun;Hwang, Jae-Joon;Kim, Jun-Seok;Lee, Song-Am
    • Journal of Chest Surgery
    • /
    • v.42 no.3
    • /
    • pp.380-383
    • /
    • 2009
  • Subclavian artery aneurysms are a very rare disease and the common causes are trauma, infection and atherosclerosis. A 69-year-old female, who had no history of trauma and infection, underwent surgical treatment for an aneurysm on a branch of the subclavian artery, and this aneurysm presented as a neck mass.

Numerical Computation of the Mass Transfer between Gaseous and Particulate Materials Considering the Hysteresis Phenomena of Atmospheric Aerosol (에어로솔의 이력현상을 고려한 대기 중 기체상/입자상 간의 물질전달 수치모사)

  • Kim, Du-Eil;Yoo, Kee-Youn
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.26 no.2
    • /
    • pp.202-218
    • /
    • 2010
  • It is well known that the atmospheric inorganic aerosol has the hysteresis phenomena depending on the history of relative humidity. However, the current computational researches have assumed that the physical/chemical state of atmospheric aerosol is only determined by a branch of hysteresis, efflorescence or deliquescence. In this work, we applied the MATLAB-based UHAEROm thermodynamics module to simulate the dynamic interaction between gaseous species $NH_3$ and $HNO_3$, and the two mono-disperse particulate populations in the course of efflorescence and deliquescence, respectively. We conducted the 10 case studies considering the particulate phase with the atmospherically prevailing chemical composition and found that the final states of the particles are determined through the qualitatively five different trajectories by the dynamic interaction between gaseous and two different kinds of particulates. As a result, we show that the coexistence of meta-stable and stable particles drives the different physical/chemical destination comparing with the ones generated from the solitary efflorescence or deliquescence branch.

Shu-gyo-ryoku: An Academic and Career Skills' Enhancement Program for Engineering Students at Gunma University

  • Matsumoto, Hiroyuki;Amagai, Kenji;Yuminaka, Yasushi;Keith, Barry
    • Journal of Engineering Education Research
    • /
    • v.15 no.5
    • /
    • pp.14-18
    • /
    • 2012
  • Shu-gyo-ryoku, a program to enhance students' academic and career skills, was begun in the academic year 2011. Under the new program, "Career Planning" and "Career Design" were introduced as part of the liberal arts education for incoming freshmen. Approximately 500 students majoring in engineering enrolled in "Career Planning" in which they study a "curriculum map" and how it relates to their future fields of employment. The curriculum map illustrates the connections between classes and increases students'understanding of the curriculum structure. In small groups, students discussed the curriculum in order to develop sketches of their career paths. In addition, students answered a career anchor test and though several communicative activities, improved their communication skills. A portfolio system was built into the university network to record the learning history of each student. Students are able to check their learning histories and reflect on the change in themselves during their academic careers.

Risk of Breast Cancer in Relation to Reproductive Factors in North-west of Iran, 2013-2014

  • Veisy, Afsaneh;Lotfinejad, Shirin;Salehi, Kamal;Zhian, Faegh
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.2
    • /
    • pp.451-455
    • /
    • 2015
  • More than one million new patients suffer from breast cancer annually in the world. In developed countries, breast cancer is the most common malignancy diagnosed among women, and in developing regions, it often ranks second to cervical cancer. This study aimed to investigate the relationship between incidence of breast cancer and reproductive factors in North-West of Iran. This retrospective analytical control-case study was conducted with 235 breast cancer patients and 235 women in the control group. Data collection tools included a set of questions with interviews and patient medical records. Data were analyzed using statistical tests: t-test, Chi-square, Fisher, and Pearson correlation coefficient. Significantly increased risks were associated between breast cancer and older age at first pregnancy, age at menopause and history of contraceptive use. A trend for decreasing risk were observed with increasing parity. Findings of this study showed no association between breast cancer and age at menarche. The study results suggested that physiological and reproductive factors may play important roles in the development breast cancer among Iranian women.

Ecological Characteristics of Paralebeda plagifera femorata (Lepidoptera: Lasiocampidae) in Korea (한국산 대만나방(나비목: 솔나방과)의 생태적 특성)

  • 심상준;이기영;황환준;한상섭;변봉규
    • Korean journal of applied entomology
    • /
    • v.39 no.2
    • /
    • pp.83-87
    • /
    • 2000
  • This study was carried out to investigate the life history of Paralebeda plagifera femorata in 1998 and 1999. Ginkgo biloba was newly known to be a host plant for the species in this study. The moth has one generation a year. It overwinted as 6th instar larva on branches of the host plant. The 9th instar larva made a rough cocoon by webbing two or three leaves, and pupated on the branch on late June. The moths emerged from early July through early August with a peak around late July. A female oviposited 205 eggs on an average on the branch, twig, or leaf margin.

  • PDF

New insights on the origin of multiple stellar populations in globular clusters

  • Kim, Jaeyeon;Lee, Young-Wook
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.43 no.1
    • /
    • pp.46.1-46.1
    • /
    • 2018
  • In order to investigate the origin of multiple stellar populations in the halo and bulge of the Milky Way, we have constructed chemical evolution models for the low-mass proto-Galactic subsystems such as globular clusters. Unlike previous studies, we assume that supernova blast waves undergo blowout without expelling the pre-enriched gas, while relatively slow winds of massive stars, together with the winds and ejecta from low and intermediate mass asymptotic-giant-branch stars, are all locally retained in these less massive systems. We find that the observed Na-O anti-correlations in metal-poor GCs can be reproduced when multiple episodes of starbursts are allowed to continue in these subsystems. A specific form of star formation history with decreasing time intervals between the stellar generations, however, is required to obtain this result, which is in good agreement with the parameters obtained from our stellar evolution models for the horizontal-branch. The "mass budget problem" is also much alleviated by our models without ad-hoc assumptions on star formation efficiency and initial mass function. We also applied these models to investigate the origin of super helium-rich red clump stars in the metal-rich bulge as recently suggested by Lee et al. (2015). We find that chemical enrichments by the winds of massive stars can naturally reproduce the required helium enhancement (dY/dZ = 6) for the second-generation stars. Disruption of proto-globular clusters in a hierarchical merging paradigm would have provided helium enhanced stars to the bulge field.

  • PDF

The length of plastic hinge area in the flanged reinforced concrete shear walls subjected to earthquake ground motions

  • Bafti, Farzad Ghaderi;Mortezaei, Alireza;Kheyroddin, Ali
    • Structural Engineering and Mechanics
    • /
    • v.69 no.6
    • /
    • pp.651-665
    • /
    • 2019
  • Past earthquakes have shown that appropriately designed and detailed buildings with shear walls have great performance such a way that a considerable portion of inelastic energy dissipation occurs in these structural elements. A plastic hinge is fundamentally an energy diminishing means which decrease seismic input energy through the inelastic deformation. Plastic hinge development in a RC shear wall in the areas which have plastic behavior depends on the ground motions characteristics as well as shear wall details. One of the most generally used forms of structural walls is flanged RC wall. Because of the flanges, these types of shear walls have large in-plane and out-of-plane stiffness and develop high shear stresses. Hence, the purpose of this paper is to evaluate the main characteristics of these structural components and provide a more comprehensive expression of plastic hinge length in the application of performance-based seismic design method and promote the development of seismic design codes for shear walls. In this regard, the effects of axial load level, wall height, wall web and flange length, as well as various features of earthquakes, are examined numerically by finite element methods and the outcomes are compared with consistent experimental data. Based on the results, a new expression is developed which can be utilized to determine the length of plastic hinge area in the flanged RC shear walls.