• Title/Summary/Keyword: Combined forces

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Position and Force Control for Two Robots with Application to Load Distribution (두 로보트의 위치 및 힘 제어의 부하분배에 관한 응용)

  • Kim, Kab-Il;Jeon, Hun-Jong;Kim, Dong-Jun
    • Proceedings of the KIEE Conference
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    • 1992.07a
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    • pp.414-416
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    • 1992
  • Stability analysis and load distribution problem of two coordinating robots using full dynamic model is studied in this paper. Dynamic models of two robots are combined with the position force control strategy and the Liapunov 2nd method is used for the proof of the stability. This analysis shows that the position and force control of two coordinating robot is always stable. Also, load distribution problem is mentioned with respect to the end-effector forces minimizing joint torques.

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Seismic Qualification of the Air Cleaning Units for Nuclear Power Plant Ulchin 5&6 (울진 원자력발전소 5,6 호기용 공기정화기에 대한 내진검증)

  • Kim, Jin-Young;Rhee, Hui-Nam;Lee, Joon-Keun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.7
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    • pp.1376-1383
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    • 2002
  • Seismic qualification of the Air Cleaning Units for nuclear power plant Ulchin 5&6 has been performed with the guideline of ASME Section III and IEEE 344 code. By using the structural and geometrical similarity analysis, the three models to be analyzed are condensed into a single model and, at the same time, the excitation forces and other operating loads for each model are encompassed with respect to different loading conditions. As the fundamental frequencies of the structure are found to be less than 33Hz, which is the upper frequency limit of the seismic load, response spectrum analysis using ANSYS is performed in order to combine the modal stresses within the frequency limit. In order to confirm the structural and electric stability of the major components, modal analysis theory is adopted to derive the required response spectrum at the component locations. As the all combined stresses obtained from the above procedures are less than allowable stresses and no mechanical or electrical failures are found from the seismic testing, the authors confirm the safety of the nuclear equipments Air Cleaning Units studied in this paper.

Influence of Foreign Culture and Hybrid Culture: The Case of Kandyan Kingdom of Sri Lanka

  • Ranathunga, Gayathri Madubhani
    • International Journal of Costume and Fashion
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    • v.13 no.2
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    • pp.53-64
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    • 2013
  • Culture has played a pivotal role in fashion from time immemorial. The objective of this research is to explore the power of cultural affiliation in fashion. The selected study setting is the Kandyan Kingdom of Sri Lanka. The Kandyan Kingdom of Sri Lanka lasted almost 3 1/2 centuries from 1474-1815. The whole period faced different foreign cultural forces. As a result of such diverse cultural influences the Kandyan dress showed a hybrid formation of Western and South Indian and Sinhalese traditional sartorial features. Sewing techniques and unsewn dress arrangement methods were mixed together. The dress became an amazing blend of Eastern and Western dress items. They combined different aspects of foreign dress together to yield a unique result. The analysis comprises observational study of actual descriptions made by observer- participants, historical records, murals of the period review of ancient literature and research papers relevant to the subject. Reliability of the data was ensured. The pictorial data were cross checked from different literary sources. Many original sources were used. Results: Culture and fashion have strong interconnection. When features of culture change, trends of fashion are gradually correspondingly changed.

Relational Characteristics and Satisfaction of Foodservice Businesses in Association to Distribution Channels (외식업체의 유통경로상 관계특성과 만족에 관한 경로모형 연구)

  • Jeon Hyo-Jin
    • Korean journal of food and cookery science
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    • v.22 no.2 s.92
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    • pp.250-257
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    • 2006
  • Foodservice industry and distribution business could make mutual prpgress when they join forces in responding to environmental uncertainty in an efficient manner. The purpose of this study was to examine the relational characteristics of domestic food service businesses and distribution firms in conjunction with the distribution channels and ensuing conflicts between them, to present possible alternatives on and how they should communicate with each other to achieve a satisfactory result. The relational characteristics and ensuing conflicts of food service businesses and distribution firms appeared to be significantly characterized by incongruities of target, role and perception. The types of relational characteristics that were triggered by the disagreement of roles and perception combined to decrease the intensity of the relational commitment. A satisfactory transactional relationship served to ease their conflicts caused by perceptual disagreement, and the soos of conflicts that were rooted in the discord of roles and of perception that increased the degree of relational commitment. As for relational performance, relational commitment, satisfaction with distribution channel and satisfaction with suppliers allowed them to maintain their relationship on a long-term basis.

Experimental study on the vibration mitigation of offshore tension leg platform system with UWTLCD

  • Lee, Hsien Hua;Juang, H.H.
    • Smart Structures and Systems
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    • v.9 no.1
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    • pp.71-104
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    • 2012
  • In this research, a typical tension-leg type of floating platform incorporated with an innovative concept of underwater tuned liquid column damper system (UWTLCD) is studied. The purpose of this study is to improve the structural safety by means of mitigating the wave induced vibrations and stresses on the offshore floating Tension Leg Platform (TLP) system. Based on some encouraging results from a previous study, where a Tuned Liquid Column Damper (TLCD) system was employed in a floating platform system to reduce the vibration of the main structure, in this study, the traditional TLCD system was modified and tested. Firstly, the orifice-tube was replaced with a smaller horizontal tube and secondly, the TLCD system was combined into the pontoon system under the platform. The modification creates a multipurpose pontoon system associated with vibration mitigation function. On the other hand, the UWTLCD that is installed underwater instead would not occupy any additional space on the platform and yet provide buoyancy to the system. Experimental tests were performed for the mitigation effect and parameters besides the wave conditions, such as pontoon draught and liquid-length in the TLCD were taken into account in the test. It is found that the accurately tuned UWTLCD system could effectively reduce the dynamic response of the offshore platform system in terms of both the vibration amplitude and tensile forces measured in the mooring tethers.

A new and simple analytical approach to determining the natural frequencies of framed tube structures

  • Mohammadnejad, Mehrdad;Kazemi, Hasan Haji
    • Structural Engineering and Mechanics
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    • v.65 no.1
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    • pp.111-120
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    • 2018
  • This paper presents a new and simple solution for determining the natural frequencies of framed tube combined with shear-walls and tube-in-tube systems. The novelty of the presented approach is based on the bending moment function approximation instead of the mode shape function approximation. This novelty makes the presented solution very simpler and very shorter in the mathematical calculations process. The shear stiffness, flexural stiffness and mass per unit length of the structure are variable along the height. The effect of the structure weight on its natural frequencies is considered using a variable axial force. The effects of shear lag phenomena has been investigated on the natural frequencies of the structure. The whole structure is modeled by an equivalent non-prismatic shear-flexural cantilever beam under variable axial forces. The governing differential equation of motion is converted into a system of linear algebraic equations and the natural frequencies are calculated by determining a non-trivial solution for the system of equations. The accuracy of the proposed method is verified through several numerical examples and the results are compared with the literature.

Innovation in how to combat the Army's military strategy for future combat victory (미래전 승리를 위한 육군의 군사전략과 싸우는 방법 혁신)

  • Jung, Min-Sub;NamKung, Seung-Pil;Park, Sang-Hyuk
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.3
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    • pp.105-109
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    • 2020
  • The Future Army in 2050 should prepare for various future threats and effectively utilize its superintelligence and hyper-connected weapons systems to develop ways of fighting new concepts to dominate multi-regional battlefields and achieve victory. First, the establishment of active and offensive military strategies based on ability. Second, the battle of central strike for enemy combat will paralysis. Third, the battle of simultaneous integrated mosaic using multidisciplinary areas. Fourth, cyber warfare based on artificial intelligence that transcends time and space. Fifth, Combined Platform War. After all, future wars will be won or lost by invisible wars on cyber space.

Vibration Fatigue for the Bogie frame of the Rubber Wheel AGT (고무차륜형 AGT 주행장치의 진동피로해석)

  • 유형선;윤성호;변상윤;편수범
    • Journal of the Korean Society for Railway
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    • v.3 no.3
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    • pp.117-124
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    • 2000
  • The rubber wheel-type AGT has two major kinds of bogie; one is the bogie type and the other steering one. Both are important vehicular structure to support the whole running vehicle and passenger loads. This paper deals with the static analysis for the two types of bogie frame subjected to combined external forces, as well as independent ones specified in UIC 515-4. Furthermore, the dynamic analysis is performed under vibrational loading conditions so as to compare dynamic characteristics, Numerical results by using commercial packages, I-DEAS and NASTRAN show that maximum stresses do not exceed the yield strength level of material used for both bogies. From an overall viewpoint of strength, the bogie type turns out to be superior to the steering type except for the case of a lateral loading. It is also observed that the steering type shows a characteristics of low frequency behavior during a course of searching for structurally weak areas to be stiffened. The vibrational fatigue analysis for each bogie frame depends on the loading time history conditions which is applied. Time History Central Database List in the NASTRAN package. Subsequent1y, the fatigue life of bogie type is longer than the steering type.

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Seismic Analysis of the Main Control Boards for Nuclear Power Plant (원자력발전소의 Main Control Boards에 대한 내진 해석)

  • Byeon, Hoon-Seok;Lee, Joon-Keun;Kim, Jin-Young
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11a
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    • pp.498-498
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    • 2001
  • Seismic qualification of the Main Control Boards for nuclear power plants has been performed with the guideline of AS ME Section III. US NRC Reg. Guide and IEEE 344 code. The analysis model of the Main Control Boards is consist of beam. shell and mass element by using the finite element method. and, at the same time. the excitation forces and other operating loads for each model are encompassed with respect to different loading conditions. As the fundamental frequencies of the structure are found to be less than 33Hz. which is the upper frequency limit of the seismic load, the response spectrum analysis using ANSYS is performed in order to combine the modal stresses within the frequency limit. In order to confirm the structural and functional integrity of the major components, modal analysis theory is adopted to derive the required response spectrum at the component locations. As all the combined stresses obtained from the above procedures are less than allowable stresses and no mechanical or electrical failures are found from the seismic testing, it concludes the Main Control Boards is dynamically qualified for seismic conditions. Although the authors had confirmed the structural and functional integrity of both Main Control Boards and all the component, in this paper only the seismic analysis of the Main Control Board is introduced.

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Development of a methodology for damping of tall buildings motion using TLCD devices

  • Diana, Giorgio;Resta, Ferruccio;Sabato, Diego;Tomasini, Gisella
    • Wind and Structures
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    • v.17 no.6
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    • pp.629-646
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    • 2013
  • One of the most common solutions adopted to reduce vibrations of skyscrapers due to wind or earthquake action is to add external damping devices to these structures, such as a TMD (Tuned Mass Damper) or TLCD (Tuned Liquid Column Damper). It is well known that a TLCD device introduces on the structure a nonlinear damping force whose effect decreases when the amplitude of its motion increases. The main objective of this paper is to describe a Hardware-in-the-Loop test able to validate the effectiveness of the TLCD by simulating the real behavior of a tower subjected to the combined action of wind and a TLCD, considering also the nonlinear effects associated with the damping device behavior. Within this test procedure a scaled TLCD physical model represents the hardware component while the building dynamics are reproduced using a numerical model based on a modal approach. Thanks to the Politecnico di Milano wind tunnel, wind forces acting on the building were calculated from the pressure distributions measured on a scale model. In addition, in the first part of the paper, a new method for evaluating the dissipating characteristics of a TLCD based on an energy approach is presented. This new methodology allows direct linking of the TLCD to be directly linked to the increased damping acting on the structure, facilitating the preliminary design of these devices.