• Title/Summary/Keyword: external forces

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NSGT-based acoustical wave dispersion characteristics of thermo-magnetically actuated double-nanobeam systems

  • Ebrahimi, Farzad;Dabbagh, Ali
    • Structural Engineering and Mechanics
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    • v.68 no.6
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    • pp.701-711
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    • 2018
  • Herein, the thermo-magneto-elastic wave dispersion answers of functionally graded (FG) double-nanobeam systems (DNBSs) are surveyed implementing a nonlocal strain gradient theory (NSGT). The kinematic relations are derived employing the classical beam theory. Also, scale influences are covered precisely in the framework of NSGT. Moreover, Mori-Tanaka homogenization model is introduced in order to obtain the effective material properties of FG nanobeams. Meanwhile, effects of external forces such as thermal and Lorentz forces are included in this research. Also, based upon the Hamilton's principle, the Euler-Lagrange equations are developed; afterwards, these equations are incorporated with those of NSGT to reach the nonlocal governing equations of FG-DNBSs. Furthermore, according to an analytical approach, the governing equations are solved to obtain the wave frequencies and phase velocities of FG-DNBSs. At the end, some illustrations are rendered to clarify the influences of a wide range of involved parameters.

Success Factors of Paris Baguette's Bakery Franchise Business: Industry Competition and Core Competence Analysis

  • Jeong, Jaeseok;Jeong, Hannara;Ko, Kihyeon;Moon, Junghoon;Kang, Hyoung Goo
    • Asia Marketing Journal
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    • v.15 no.2
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    • pp.1-27
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    • 2013
  • The main goal of this study is to examine the competition intensity in the Korean bakery franchise industry and to identify the core competencies of the industry's leading company, Paris Baguette. The frameworks of PEST analysis, Cross Impact analysis, a Five Forces Model, a Value Chain, and VRIO analysis. PEST and Cross Impact analysis were employed to investigate the industry's external environment, and the results indicated that 'increased attention on corporate's Creating Shared Value (CSV) activities' is the most influential factor among others. The analysis using the Five Forces Model found industry rivalry and substitutes were the greatest threats. Finally, the results of Value Chain and VRIO analysis identified four core competencies of Paris Baguette: its CEO's craftsmanship, e-procurement system, quality of dormant dough, and hub system. Multiple managerial implications are suggested for practitioners in the marketing area, especially in the saturated market environment.

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Beach Deformation Caused by Typhoon Chaba in 2016 Along the Manseongri Coast Related Coastal Improvement Project (연안정비사업이 수행된 만성리 해수욕장에서 2016년 태풍 차바에 의한 해빈변화)

  • Park, Il Heum;Park, Wan-Gyu;Jeong, Seung Myong;Kang, Tae-Soon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.6
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    • pp.710-718
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    • 2017
  • After Typhoon Chaba (No.18, 2016) collided with Manseongri Beach, a coastal improvement project was carried out since strong external forces such as waves, storm surges and wave-induced currents were observed to cause beach deformation. The shoreline, beach area and beach volume were periodically surveyed. On the basis of this field data, the beach deformation that occurred at Manseongri Beach has been formally described. Over three months after beach nourishment work began, the beaches were gradually stabilized in terms of natural external forces. However, this stabilization was interrupted by Typhoon Chaba. After two months of typhoon weather, the beach returned to a stable state and no changes were observed until one year after the beach recovery work. Just after the typhoon hit, the shoreline receded from the northern side, where no reduction of external forces occurred, while the rear beach area submerged by breakwater advanced. Also, the beach volume decreased by $3,395m^3$ after the typhoon, due to erosion that occurred on the northern beach, with deposition taking place on the southern backshore area. Therefore, it has been concluded that the coastal improvement project undertaken at Manseongri Beach has significantly contributed to conservation in areas of wave-dominant sediment transport.

A Study on the Effect of External Electromagnetic force in MIG Welding (MIG 용접 시 외부 전자기력이 미치는 영향에 관한 연구)

  • Kim Jae Seong;Kim Yong;Ryu Deok Hui;Lee Bo Yeong
    • Proceedings of the KWS Conference
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    • v.43
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    • pp.171-173
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    • 2004
  • Electromagnetic force is one of the most important factor that effect on metal transfer mode, short-circuit rate, spatter generation rate and mechanical properties of weld metal etc. Also, shielding gas and welding current have influence on metal transfer mode in GMAW. In this paper, different ways for external electromagnetic forces are applied by attaching cylindrically rounded conducting wire solenoid on touch tip holding. With the applied electromagnetic field, the arc transfer mode changes from normal mode to rotating mode and spatter generation decreased in electromagnetic fields(N-pole). In MIG welding, the influences of electromagnetic force on the spatter generation showed different tendency as in the $CO_2$ welding. It is possible reasons were discussed.

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Inspecting Driving Forces of Business Cycles in Korea

  • Jung, Yongseung
    • East Asian Economic Review
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    • v.23 no.4
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    • pp.409-427
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    • 2019
  • This paper sets up a new Keynesian model with external habit to explore the role of each shock over business cycles in Korea. The estimated model via maximum likelihood shows that the productivity shock plays a pivotal role in explaining the output variations before and after the financial crisis since mid-1970s. It also shows that the model with external habit is more successful in explaining the business cycles in Korea after the Asian financial crisis than the model without habit. The monetary policy shock which dominates by accounting for more than 70 percent of the unconditional variance of the inflation rate before the financial crisis is less important in the inflation rate fluctuations after the financial crisis. This partly reflects the regime change of the monetary policy to the inflation targeting rule after the financial crisis.

A study on the Manoeuvring Motion Under the Condition of External Forces in Restricted Waterways

  • Lee Chun Ki;Kang Il Kwon;Yoon Jeom Dong
    • Proceedings of KOSOMES biannual meeting
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    • 2003.11a
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    • pp.123-126
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    • 2003
  • In the present paper, the analysis is on the safe navigation between ships moving each other in restricted waterways under the external force, such as wind or current The numerical simulation of manoeuvring motion was carried out to propose an appropriate safe speed and distance between ships, which is required to avoid marine disasters from the viewpoint of marine safety. From the inspection q this investigation, it indicates the following result In case of proximal navigation between ships under the wind and current, the low-speed vessel is potentially hazardous because the rudder force if low-speed vessel needed for steady-state course-keeping is not sufficient, compared to the high-speed vessel The manoeuvring characteristic based on this investigation will be very useful for keeping the safety of navigation from the practical point of ships design and traffic control in restricted waterways.

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An Experimental Study on the Spray Characteristics of Deflector Nozzle (충돌형 노즐의 분무특성에 관한 실험적 연구)

  • Kim K. H.;Choi Y. H.;Yoon S. J.
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.291-294
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    • 2002
  • This study describes the external spray characteristics of deflector nozzle such as the breakup procedures of liquid sheet, spray angle, discharge coefficient and bubble behaviors of spray and SMD at deflector nozzle. In order to visualize the spray behaviors shadow graphy technique were used. According to the increase of injection pressure, development of the spray passes through the dribbling, distoted jet, closed bubble due to the contraction by surface tension forces, the bubble opens into hollow tulip shape, and the curved surface straightened to form a conical sheet like as the simplex swirl atomizer. Spray cone angle was nearly 90 deg. Variations of SMD were examined in order to describe the dependency of SMD on the injection pressure and orifice diameter. The shape of deflector and oriffice diameter had an effect on the discharge coefficient.

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Analysis of leakage factors affecting ECV performance in variable compressor

  • Mahmud, Md. Iqbal;Cho, Haeng Muk
    • Journal of Energy Engineering
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    • v.23 no.4
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    • pp.183-188
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    • 2014
  • Solenoid operated electromagnetic control valve (ECV) using in an external variable displacement swash plate type compressor is widely used for air conditioning control system because of its low energy consumption and high efficient characteristics. ECV controls the entire vehicle air conditioning system by means of a pulse width modulation (PWM) system that supplied from an external controller. Different pressure ports located within ECV has important functions to control the air/refrigerant flow through its internal passages. The flow paths are preciously maintained with acceptable ranges of leakage (gap) between the parts inside it which is followed by effective design and critical dimensioning of its internal features. Therefore, it saves energy losses from the solenoid operation as well as ensures the balance of forces within it. The research paper highlights analysis of the leakages (at different pressure ports) and dimensioning tolerance factors that affects the ECV performance.

Chaotic Vibration of a Straight Pipe Conveying Oscillatory Flow (조화진동유동을 포함한 직선파이프계의 혼돈운동 연구)

  • Pak, Chul-Hui;Hong, Sung-Chul;Jung, Wook
    • Journal of KSNVE
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    • v.6 no.2
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    • pp.233-244
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    • 1996
  • In this paper chaotic mothions of a straight pipe conveying oscillatory flow and being subjected to external forces such as earthquake are theoretically investigated. The nonlinear partial differential equation of motion is derived by Newton's method. In this equation, the nonlinear curvature of the pipe and the thermal expansion effects are contained. The nonlinear ordinary differential equation transformed from that partial differential equation is a type of Hill's equations, which have the parametric and external exciation term. This original system is transfered to the averaged system by the averaging theory. Bifurcation curves of chaotic motion of the piping system are obtained in the general case of the frequency ratio, n by applying Melnikov's method. Numerical simulations are performed to demonstrate theorectical results and show strange attactors of the chaotic motion.

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The effect of external electromagnetic force on droplet in GMAW (가스메탈 아크용접법에서 전자기력이 아크 현상에 미치는 영향에 관한 연구)

  • Lee, Sung-Ho;Lee, Jae-Yoon;Kim, Yong;Kim, Jae-Sung;Lee, Bo-Young
    • Proceedings of the KWS Conference
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    • 2003.11a
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    • pp.221-223
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    • 2003
  • Effects of electromagnetic force which is one of the most important factor of metal transfer that affects bead geometry and microstructure of weld metal in GMAW(gas metal arc welding). In this paper, different ways of external electromagnetic forces were applied on GMAW process and their effects on the welding were studied. On certain conditions, better bead geometry, better influence on the arc and metal transfer mode and higher welding efficiency could be obtained. Experimental methods and their results will be presented.

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