• Title/Summary/Keyword: surface acting

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Analysis of Load Value acting Free Falling Object according to Disturbance using Nonlinear Load Control Model (비선형 하중 제어 모델에서 외란에 따른 자유낙하 물체에 작용하는 하중값 분석)

  • Wang, Hyeon-Min;Woo, Kwang-Joon
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.47 no.2
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    • pp.55-59
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    • 2010
  • Recently it is tried to use load control model for maneuver moving object. MIN design method proposed to solve control problem of nonlinear system using load concept. The Min design method shows direct method for finding control value on the load control model. In this paper, is shown realization free falling model using nonlinear load control model and analysis of load values acting falling object according to disturbance. And made a trajectory according to acting load values due to disturbance. This paper's result is able to be applied to design algorithm for improvement accuracy of MLRS, GPS air-to-surface missile(ASM) and returning spacecraft with nonlinear model predictive control.

An Empirical Analysis of the Impact of Hospital Employees' Emotional Intelligence on Emotional Labor Strategies and Innovative Activities (병원근로자의 감성지능이 감정노동전략 및 혁신활동에 미치는 영향에 관한 실증분석)

  • Kang, Hyeon Jin;Jeon, Hyeon Gyu;Kim, Min-Yong
    • The Journal of the Korea Contents Association
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    • v.15 no.12
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    • pp.387-406
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    • 2015
  • Recently emotional labor is an essential situation for hospital employees in relation to surface and deep acting as the core of emotional labor strategies. This study empirically examines the relation between hospital employees' emotional intelligence and emotional labor strategies in the context of emotional labor. For empirical experiments, we conducted a questionnaire survey targeting hospital employees, and we employed the method of Partial Least Squares (PLS) for data analysis. Major findings are as follows. Hospital employees' emotional intelligence including self emotion appraisal, others' emotion appraisal, regulation of emotion, and use of emotion, have a significantly positive effect on hospital employees' deep acting. And hospital employees' deep acting has a significantly positive effect on hospital employees' organizational attachment, knowledge sharing intentions, and innovative activities.

Tractor Design for Rotary Tillage Considering Lift Resistance (상승저항력을 고려한 로터리경운작업을 위한 승용트랙터의 설계)

  • Sakai, J.;Yoon, Y.D.;Choe, J.S.;Chung, C.J.
    • Journal of Biosystems Engineering
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    • v.18 no.4
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    • pp.344-350
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    • 1993
  • The purpose of this study is to develop design equations to calculate optimum specifications and dimensions such as weight, engine horsepower, etc. of the tractor necessary to perform stable rotary tillage. The main results of this study are as follows. 1. A wheel-lug ought to receive a special resistance in downward direction which resists the lug's upward motion on wet sticky soil surface. The authors introduce a new academic name of the "lift resistance(上昇抵抗力, 상승저항력)" for such a force which resists retraction of a wheel lug from the soil in the upward trochoidal motion. This force is composed of the frictional force acting on the trailing and the leading lug side, and the "perpendicular adhesion(鉛直付着力, 연직부착력)" acting on the lug face and the undertread face on adhesive soil. 2. The "lift resistance ratio(上昇抵抗力係數, 상승저항력계수)" and the "perpendicular adhesion ratio(鉛直付着力係數, 연직부착력계수)" were defined, which are something similar to the definition of the motion resistance ratio, the traction coefficient, etc. 3. The design equation of the optimum weight of a rotary tiller mounted on the tractor derived by calaulating the forces acting on the rotary blades. 4. The design equations to calculate optimum specifications and dimensions such as weight, engine horsepower, etc. of the tractor necessary to perform stable rotary tillage were derived. It becomes clear that the optimum weight of a rotary tiller and a tractor can be estimated in planning design by means of putting about 21 design factors of the target into the equation. These equations are useful for planning design to estimate the optimum dimensions and specifications of a rotary tiller as well as a tractor by the use of known and/or unknown design parameters.

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Clinical Nurses' Experience of Emotional Labor (임상간호사의 감정노동 경험)

  • Yom, Young-Hee;Lee, Hyunsook Zin;Son, Heesook
    • Journal of Korean Clinical Nursing Research
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    • v.22 no.3
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    • pp.314-326
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    • 2016
  • Purpose: The purpose of this study was to understand the experience of emotional labor of clinical nurses in medical institutes. Methods: A total of 26 nurses from 11 hospitals participated in the study. Six focus groups were organized and 4 to 5 nurses took part in each group. The compositional factors of groups included clinical experience, age, gender, work place and position. Data collection was conducted through focus group interview and it was proceeded by the time of data saturation. In this qualitative study, content analysis was conducted. Results: Five themes, 14 categories, and 33 subcategories, were emerged. The themes were 'Restrain themselves', 'Communion to the patients', 'Working environment provoking emotional tension', 'Respond to emotional events', 'Recovery of emotional energy'. Conclusion: Results indicated that surface acting of emotional labor such as, repression of personal desire and presenting the emotions that the organization ask nurse to express was related to psychosomatic symptoms, depression, burnout, poor job performance, increased mistakes, and low job satisfaction which eventually leads to nurses' turnover. In order to reduce negative influence of emotional labor, it is necessary to build positive organizational culture, to provide support from managers and co-workers. It is also important to improve work environment in order to do more deep acting since sharing emotions with patients can reduce the negative influence of emotional labor.

Numerical investigation of truck aerodynamics on several classes of infrastructures

  • Alonso-Estebanez, Alejandro;del Coz Diaz, Juan J.;Rabanal, Felipe P.A lvarez;Pascual-Munoz, Pablo;Nieto, Paulino J. Garcia
    • Wind and Structures
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    • v.26 no.1
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    • pp.35-43
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    • 2018
  • This paper describes the effect of different testing parameters (configuration of infrastructure and truck position on road) on truck aerodynamic coefficients under cross wind conditions, by means of a numerical approach known as Large Eddy Simulation (LES). In order to estimate the air flow behaviour around both the infrastructure and the truck, the filtered continuity and momentum equations along with the Smagorinsky-Lilly model were solved. A solution for these non-linear equations was approached through the finite volume method (FVM) and using temporal and spatial discretization schemes. As for the results, the aerodynamic coefficients acting on the truck model exhibited nearly constant values regardless of the Reynolds number. The flat ground is the infrastructure where the rollover coefficient acting on the truck model showed lowest values under cross wind conditions (yaw angle of $90^{\circ}$), while the worst infrastructure studied for vehicle stability was an embankment with downward-slope on the leeward side. The position of the truck on the road and the value of embankment slope angle that minimizes the rollover coefficient were determined by successfully applying the Response Surface Methodology.

Numerical determination of wind forces acting on structural elements in the shape of a curved pipe

  • Padewska-Jurczak, Agnieszka;Szczepaniak, Piotr;Bulinski, Zbigniew
    • Wind and Structures
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    • v.30 no.1
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    • pp.15-27
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    • 2020
  • This paper reports the study on development and verification of numerical models and analyzes of flow at high speed around structural elements in the shape of a curved pipe (e.g., a fragment of a water slide). Possibility of engineering estimation of wind forces acting on an object in the shape of a helix is presented, using relationships concerning toroidal and cylindrical elements. Determination of useful engineering parameters (such as aerodynamic forces, pressure distribution, and air velocity field) is presented, impossible to obtain from the existing standard EN 1991-1-4 (the so-called wind standard). For this purpose, flow at high speed around a torus and helix, arranged both near planar surface and high above it, was analyzed. Analyzes begin with the flow around a cylinder. This is the simplest object with a circular cross-section and at the same time the most studied in the literature. Based on this model, more complex models are analyzed: first in the shape of half of a torus, next in the shape of a helix.

Wave force Acting on the Artificial Rock installed on a Submerged Breakwater in a Regular Wave field (잠제상에 설치된 표식암(의암)에 작용하는 규칙파파력의 실험적 연구)

  • 배기성;허동수
    • Journal of Ocean Engineering and Technology
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    • v.16 no.6
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    • pp.7-17
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    • 2002
  • Recently, artificial rocks, instead of buoys, have been placed on the submerged breakwater to indicate its location. The accurate estimation of wave forces on these rocks is deemed necessary for their stability design. Characteristics of the wave force, however, are expected . to be very complicated because of the occurrence of breaking or post-breaking waves. In this regard, wave forces exerted on an artificial rock have been investigated in this paper. The maximum wave force has been found to strongly dependent on the location and shape of the artificial rock that is placed on the submerged breakwater. The plunging breaker occurs near the loading cram edge of a submerged breakwater, which cause impulsive breaking wave force on the rock. Using the Morison equation, with the velocity and acceleration at the front face of the artificial rock and varying water surface level, it is possible to estimate wave forces, even impulsive breaking wave forces, that are acting on the rock installed on a submerged breakwater. The vertical wave force is also found to depend, significantly, on the buoyant force.

A Computational Study About Behavior of an Underwater Projectile and Prediction of Surficial Pressure Loading (수중 운동체의 거동 및 표면 압력하중 예측에 관한 수치적 연구)

  • Jo, Sung Min;Kwon, Oh Joon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.3
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    • pp.405-412
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    • 2017
  • In the present study, two phase flows around a projectile vertically launched from an underwater platform have been numerically investigated by using a three dimensional multi-phase RANS flow solver based on pseudo-compressibility and a homogeneous mixture model on unstructured meshes. The relative motion between the platform and projectile was described by six degrees of freedom(6DOF) equations of motion with Euler angles and a chimera technique. The propulsive power of the projectile was modeled as the fluid force acting on the lower surface of the body by the compressed air emitted from the platform. Qualitative analysis was conducted for the time history of vapor volume fraction distributions. Uncorking pressure around the projectile and platform was analyzed to predict impact force acting on the surfaces. The results of 6DOF analysis presented similar tendency with the surficial pressure distributions.

The Moderating Effects of Social Support between Emotional Labor and Job Satisfaction in Clinical Nurses (임상간호사의 감정노동과 직무만족 간의 관계에서 사회적 지지의 조절효과)

  • Han, Hye-Yul;Lee, Ji-Young;Jang, Insun
    • Korean Journal of Occupational Health Nursing
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    • v.24 no.4
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    • pp.331-339
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    • 2015
  • Purpose: The purpose of this study was to investigate the moderating effects of social support between emotional labor and job satisfaction in clinical nurses. Methods: Participants were 311 clinical nurses and data were collected from July 11th to 18th, 2014. The data were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficient and hierarchical multiple regression with SPSS 21.0. Results: The job satisfaction indicated a significant relationship to surface-acting (r=-.191, p=.001), deep-acting (r=.179, p=.002) and social support (r=.342, p<.001) respectively. Emotional labor significantly affected job satisfaction (F=11.592, p<.001), and explained 5.4% of the variance in job satisfaction. The social support acted as a moderator on the relationship between emotional labor and job satisfaction at significant level (F=11.416, p<.001). Conclusion: The results of this study suggest that it is important to develop social support promoting and stress relief program for clinical nurses to improve job satisfaction.

On the Improved Numerical Method for Hydrodynamic Forces Acting on an Arbitrary Cylinder in the Time Domain (2차원 주상체의 강제 동요시 동유체력의 시간 영역 해석법에 관하여)

  • Y.S.,Shin;K.P.,Rhee
    • Bulletin of the Society of Naval Architects of Korea
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    • v.27 no.1
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    • pp.63-72
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    • 1990
  • The linear hydrodynamic forces, acting on a forced oscillating cylinder from its mean position on a free surface with a small amplitude, are calculated in the time domain. The integral equation method using a time dependent Green function is employed. The numerical results for the heaving and swaying circular cylinder are shown and give good agreements with others Furthermore it is shown that the use of the Green function, which is expressed by a series expansion or asymptotic expansion according to time range, reduces computing time greatly.

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