• Title/Summary/Keyword: Virginia type

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Effect of flexural and shear stresses simultaneously for optimized design of butterfly-shaped dampers: Computational study

  • Farzampour, Alireza;Eatherton, Matthew R.;Mansouri, Iman;Hu, Jong Wan
    • Smart Structures and Systems
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    • v.23 no.4
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    • pp.329-335
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    • 2019
  • Structural fuses are made up from oriented steel plates to be used to resist seismic force with shear loading resistance capabilities. The damage and excessive inelastic deformations are concentrated in structural fuses to avoid any issues for the rest of the surrounding elements. Recently developed fuse plates are designed with engineered cutouts leaving flexural or shear links with controlled yielding features. A promising type of link is proposed to align better bending strength along the length of the link with the demand moment diagram is a butterfly-shaped link. Previously, the design methodologies are purely based on the flexural stresses, or shear stresses only, which overestimate the dampers capability for resisting against the applied loadings. This study is specifically focused on the optimized design methodologies for commonly used butterfly-shaped dampers. Numerous studies have shown that the stresses are not uniformly distributed along the length of the dampers; hence, the design methodology and the effective implementation of the steel need revisions and improvements. In this study, the effect of shear and flexural stresses on the behavior of butterfly-shaped links are computationally investigated. The mathematical models based on von-Mises yielding criteria are initially developed and the optimized design methodology is proposed based on the yielding criterion. The optimized design is refined and investigated with the aid of computational investigations in the next step. The proposed design methodology meets the needs of optimized design concepts for butterfly-shaped dampers considering the uniform stress distribution and efficient use of steel.

A Comparative Study of Communication Type and Stress Coping Style between Hwabyung Patients Group and Non-Hwabyung Patients Group (화병군과 비화병군의 의사소통 유형 및 스트레스 대처 방식 비교 연구)

  • Choi, Yoon-Hee;Jin, Mu-Kyoung;Kim, Bo-Kyung
    • Journal of Oriental Neuropsychiatry
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    • v.26 no.4
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    • pp.365-382
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    • 2015
  • Objectives: Interpersonal stress is a major cause and aggravating factor of Hwabyung. The purpose of this study was to compare communication type and stress coping style between the Hwabyung patients group and non-Hwabyung patients group. Methods: The total number of study participants was 101. Based on the Hwabyung symptom scale, the study participants were divided into Hwabyung patients group (30 patients) and non-Hwabyung patients group (43 patients; control group), and the others were excluded from the study . All included patients were administered the Virginia Satir’s communication type questionnaire and stress coping scale based on Folkman & Lazarus’s theory. The independent t-test was used to determine the statistical significance between the features of communication types and stress coping styles in each group. In addition, Spearman correlation analysis was used to identify the relationship between communication types and stress coping styles. Results and Conclusions: 1. Communication types differed significantly between the Hwabyung patients group and non-Hwabyung patients group. 2. Hwabyung patients scored significantly higher in each dysfunctional communication type than functional communication type. Scores of placating stance and super-reasonable stance, which were subtypes of dysfunctional communication type, were high in the Hwabyung patients group. The non-Hwabyung patients group scored the highest in Congruent stance, classified as functional communication type. 3. Stress coping style was not significantly different between the two groups.

A New Short Stem, Lodging Resistance and High Yielding Vegetable Peanut cultivar, "Jopyeong" (조숙 단경 내도복 다수성 풋땅콩 "조평")

  • Pae, Suk-Bok;Park, Chang-Hwan;Cheong, Young-Keun;Jung, Chan-Sik;Lee, Myung-Hee;Lee, Yu-Young;Hwang, Chung-Dong;Oh, Se-Kwan;Kim, Jung-Tae;Park, Keum-Yong;Kim, Wook-Han;Choi, Gyu-Hwan;Lee, Jae-Chul;Jeong, Byung-Joon;Kim, Ho-Young
    • Korean Journal of Breeding Science
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    • v.40 no.1
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    • pp.63-67
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    • 2008
  • A new peanut cultivar "Jopyeong" (Arachis hypogaea ssp. hypogaea L.) was developed at the Yeongnam Agricultural Research Institute, NICS, in Milyang in 2006. It was developed from the cross between the very short stem cultivar "CUP brittle" and the high-yielding cultivar "Daekwang". "Jopyeong" which is Virginia plant type has 23 branch number per plant with early maturing and ellipse-shaped large kernel. Each pod has two grains with brown testa and 100 seed weight was 87g in the regional yield trials (RYT). This variety also showed more resistant to late leaf spots compared with check one. Especially it has resistance to lodging owing to short stem and erect plant type. In the regional yield trials "Jopyeong" was out-yielded than check variety by 11% with 8.37 ton/ha for fresh pod and by 4% with 3.95 ton/ha for grain.

Factors that Influence Sexual Intercourse among Middle School Students: Using Data from the $8^{th}$ (2012) Korea Youth Risk Behavior Web-based Survey (중학생의 성관계 경험 영향요인: 제8차(2012년) 청소년건강행태온라인조사 통계를 이용하여)

  • Gwon, Seok Hyun;Lee, Chung Yul
    • Journal of Korean Academy of Nursing
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    • v.45 no.1
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    • pp.76-83
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    • 2015
  • Purpose: The purpose of this study was to investigate factors that influence sexual intercourse among middle school students in South Korea. Methods: Using statistics from the 8th (2012) Korea Youth Risk Behavior Web-based Survey, hierarchical logistic regression analysis was conducted. The study sample comprised 37,297 middle school students aged primarily 12 to 15. Results: The significant predictors of sexual intercourse were grade, ever smoking, ever drinking, habitual or purposeful drug use, economic status, weekly allowance, cohabitation with family, and type of school. Conclusion: The results suggest that intensified sex education is needed not only in the 1st grade of middle school, but also in the upper grades of elementary school. Sexual health interventions for high-risk groups may be needed, given the factors predicting sexual intercourse.

Computational Methods for On-Node Performance Optimization and Inter-Node Scalability of HPC Applications

  • Kim, Byoung-Do;Rosales-Fernandez, Carlos;Kim, Sungho
    • Journal of Computing Science and Engineering
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    • v.6 no.4
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    • pp.294-309
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    • 2012
  • In the age of multi-core and specialized accelerators in high performance computing (HPC) systems, it is critical to understand application characteristics and apply suitable optimizations in order to fully utilize advanced computing system. Often time, the process involves multiple stages of application performance diagnosis and a trial-and-error type of approach for optimization. In this study, a general guideline of performance optimization has been demonstrated with two class-representing applications. The main focuses are on node-level optimization and inter-node scalability improvement. While the number of optimization case studies is somewhat limited in this paper, the result provides insights into the systematic approach in HPC applications performance engineering.

A Study of Hospital Infection in the Postoperative Patients (수술후 병원 감염 발생과 입원일수 및 수술 소요 시간과의 관계)

  • 박정호;윤혜상
    • Journal of Korean Academy of Nursing
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    • v.16 no.2
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    • pp.70-76
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    • 1986
  • This study was aimed to observe the incidences and types of hospital infections and to compare the length of hospitalization and of the operation between the infected Patients and those of non-infected after the operations. The subject of study were 465 patients who had been operated surgically in a University Hospital from March 1 to April 30, 1985. The data were collected by reviewing medical charts of subjects. The criteria to diagnose hospital infection for this study had been revised the one utilized at University of Virginia Hospital in the U.S. Summary of the results were as follows: 1. The incidence rate of hospital infection was 6 %. The type of infection with higher incidence rate in order were wound infection(28.5%)urinary infection(28.5%), fever of unknown origin (25%) and septicemia (18%). 2. There was a statistically significant difference in the duration of hospitalization between the patient group without it (t=265.2, p<0.005). 3. There was a statistically significant difference in the duration of operation between the patient group with it (t=75.0, p<0.005).

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Occurrance of Peanut Web Blotch Caused by Phoma arachidicola Marasas, in Korea (Phoma arachidicola Marasas 에 의한 땅콩 그물무늬병의 발생)

  • Park, Kyung-Seok;Chung, Bong-Koo
    • The Korean Journal of Mycology
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    • v.19 no.3
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    • pp.226-230
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    • 1991
  • Since it was firstly identified in Suweon during the growing season in 1986, this fungus of peanut web blotch, Phoma arachidicola, has been widely distributed to the major peanut growing areas throughout the whole country. Disease symptoms appeared on the adaxial surface of peanut like ink drop lesion with net form, and finally turned to dark brown blotch. The fungus isolated was revealed to form dark brown colonies on PD agar at $28^{\circ}C$, resulting 4.5 mm mycelial extension per day. Hyaline conidia were observed to be either aseptate or single septeted, and sized with the ellipsoidal to cylindrical shape $3.0{\times}14.5\;{\mu}m$. The optimum temperature was ranged 24 to $26^{\circ}$ in the grwoth. Virginia type peanut was more resistant to the fungus than Spainish type in the field reaction.

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Polyetherimide/Dicyanate Semi-interpenetrating Polymer Networks Having a Morphology Spectrum

  • Kim, Yu-Seung;Min, Hyun-Sung;Kim, Sung-Chun
    • Macromolecular Research
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    • v.10 no.2
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    • pp.60-66
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    • 2002
  • The morphology, dynamic mechanical behavior and fracture behavior of polyetherimide (PEI)/dicyanate semi-interpenetrating polymer networks (semi-IPNs) with a morphology spectrum were analyzed. To obtain the morphology spectrum, we disported PEI particles in the procured dicyanate resin containing 300 ppm of zinc stearate catalyst. The semi-IPNs exhibited a morphology spectrum, which consisted of nodular spinodal structure, dual-phase morphology, and sea-island type morphology, in the radial direction of each dispersed PEI particle due to the concentration gradient developed by restricted dissolution and diffusion of the PEI particles during the curing process of the dicyanate resin. Analysis of the dynamic mechanical data obtained by the semi-IPNs demonstrated that the transition of the PEI-rich phase was shifted toward higher temperature as well as becoming broader because of the gradient structure. The semi-IPNs with the morphology spectrum showed improved fracture energy of 0.3 kJ/$m^2$, which was 1.4 times that of the IPNS having sea-island type morphology. It was found that the partially introduced nodular structure played a crucial role in the enhancement of the fracture resistance of the semi-IPNs.

The role of extensional rheology in polymer processing

  • Baird, Donald G.
    • Korea-Australia Rheology Journal
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    • v.11 no.4
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    • pp.305-311
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    • 1999
  • The shear behavior of polymers obtained by means of devices such as capillary and cone-and-plate rheo-meters is commonly used to assess their processing performance and as a characterization tool. However, the number of instances when two polymers have the same shear properties but perform differently during certain types of processing operations (e.g. film blowing and sheet extrusion) indicate that shear properties alone may not be sufficient to characterize polymeric fluids. We begin by defining the kinematics of shear-free or extensional flow and the associated material functions. The extensional and shear behavior of three different types of polyethylene (PE) are then compared to illustrate the points that one cannot ascertain the extensional properties of polymer melts from their shear properties and, furthermore, there may not be a simple relation between properties obtained from one type of extensional flow and those of another type. The kinematics of most processing flows are extensional rather than shear in nature, and , hence, the performance of polymers during processes such as fiber spinning, film casting, film blowing, thermoforming, blow molding, and even extrusion is more readily accounted for through extensional viscosity measurements. Methods for carrying out extensional flow measurements are then reviewed including approximate methods. To illustrate the sensitivity of extensional viscosity measurements to subtle changes in the molecular architecture of PEs, results are presented for samples with a narrow molecular weight distribution but with varying numbers of long chain branches. Finally, constitutive equations which allow one to separate shear and extensional flow behavior are discussed as any attempts to simulate the subtle processing differences between two polymers will require constitutive equations of this nature.

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Modelling Growth and Yield for Intensively Managed Forests

  • Burkhart, Harold E.
    • Journal of Forest and Environmental Science
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    • v.24 no.3
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    • pp.119-126
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    • 2008
  • Growth and yield prediction methods, ranging from whole-stand models to individual-tree models, have been developed for forest types managed for wood production. The resultant models are used for a host of purposes including inventory updating, management planning, evaluation of silvicultural alternatives, and harvest scheduling. Because of the large investment in developing growth and yield models for improved genotypes and silvicultural practices for loblolly pine (Pinus taeda) in the Southern United States, this region serves to illustrate approaches for modelling intensively managed forests. Analytical methods and computing power generally do not restrict development of reliable growth and yield models. However, long-term empirical observations on stand development, which are time consuming and expensive to obtain, often limit modelling efforts. Given that growth and yield models are used to project present volumes and to evaluate alternative treatment effects, data of both the inventory type and the experimental type are needed. Data for developing stand simulators for loblolly pine plantations have been obtained from a combination of permanent plots in operational forest stands and silvicultural experiments; these data collection efforts are described and summarized. Modelling is essential for integrating and synthesizing diverse information, identifying knowledge gaps, and making informed decisions. The questions being posed today are more complex than in the past, thus further accentuating the need for comprehensive models for stand development.

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