• Title/Summary/Keyword: mass uncertainty

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Evaluation and Adjustment of Lateral Displacement of Complex-shaped RC Tall Buildings Considering the Displacement by Tilt Angle of Each Floor (층경사각에 의한 횡변위를 고려한 비정형 고층건물의 횡변위 평가/보정)

  • Kim, Yungon
    • Journal of the Korea Concrete Institute
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    • v.27 no.5
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    • pp.551-558
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    • 2015
  • Lateral displacement in the most complex-shaped tall buildings is caused by eccentric gravity loads which are induced by the difference in location between a center of mass and a center of stiffness. The lateral displacements obtained from analysis, using conventional procedures, are prone to overestimate the actual values because much of realignment efforts made during construction phase are ignored. In construction sequence analysis, the self-leveling of slab and the verticality of columns/walls could be considered at each construction stage. Moreover, the displacement compensation can be achieved by manual process such as re-centering - locating to global coordinates through surveying. Because the lateral displacement increases with the building height, it is necessary to set up adjustment plan through construction stage analysis in advance in order to result in displacements less than the allowable limits. Because analytical solution includes lots of assumptions, the pre-adjusting displacement should be reasonably controlled with considerations for the uncertainty due to these assumptions.

An Exploratory Study on the Interaction among Local Broadcast Stations based on Market Environment (시장 환경에 입각한 지역 지상파 방송사 조직의 상호작용 특성에 대한 탐사적 연구)

  • Kwon, Jang-Won
    • Korean journal of communication and information
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    • v.52
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    • pp.27-47
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    • 2010
  • This study analyzes the latest statistics for 3 years based on the traits of market environment, internal organization characteristics(the size and distribution of workforce), and financial structure, and then, investigates the interactivity traits and drawbacks between organization and market environment, among the local broadcast stations, and, among the type of work in the internal organization, by interviewing with broadcasters working at the local stations. Major findings of this studies are : at first, statistically, the conditions of local market environment, the size of local station workforce, financial structure are very poor. And, the interactivity among the local broadcast stations have so many difficulties because of a conflict of interest. So, for getting over a difficult situation at the local stations, in addition to planning to support local stations with various policies, government and local stations should seek for solution to overcome the conflict of interest jointly.

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Pulmonary Infarction Associated with Fracture of Right Clavicle and Multiple Ribs (우측 쇄골 및 늑골골절과 동반된 폐경식 1례)

  • 김수성;이종임
    • Journal of Chest Surgery
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    • v.30 no.9
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    • pp.941-944
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    • 1997
  • Pulmonary infarction is rarely diagnosed with certainty except at postmortem examination. Part of this uncertainty is because of the inability to distinguish between hemorrhage, congestive a electasis, and necrosis clinically and radiographically. The pathogenesis of pulmonary infarction is poorly understood. It is dif%cult to induce pulmonary infarction in animals by ligation of the arterial supply to the lung. Many factors seem to be important in its pathogenesis, in addition to congestive heart failure, malignant tumor, thrombophlebitis, chronic obstructive lung disease, nephrotic syndrome, and postopeiative state. However, pulmonary infarction have not been reported in association with chest trauma. We report a case of pulmonary infarction associated with fractures of right clavicle and multiple ribs. A 45-year-old male had admitted due to right chest pain and dyspnea, which developed after right chest trauma occurred at about 3 weeks ago. He was treated at local clinics under the diagnosis of fractures of right clavicle and ribs until the admission. Chest CT disclosed a huge mass with central low density in right upper lobe, and small masses were also seen on both l ng fields. Open lung biopsy resulted in negativity for the malignancy. Clinical symptoms and radiological findings were not improved by conservative treatment. Right upper lobectomy was done eventually. The final diagnosis was pulmonary infarction. And, the patient has been well after operation.

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Investigation of Error Factors from an Impact Hammer Test for Developing a Statistic Based Technique for Model Updating (통계 기반 모델 개선을 위한 임팩트 해머 실험의 오차 요인 분석)

  • Lee, Su;Lee, Jin Woo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.2
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    • pp.185-198
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    • 2016
  • In this work, experimental errors from an impact hammer test were investigated to develop a statistic-based technique for updating a finite element model. Digital signal processing was analyzed by using theoretical models and experiments when errors occurred during the experimental procedure. First, the duration time and peak level of the excitation signal, the stiffness and position of elastic springs connecting the specimen as well as the support, position and mass of the accelerometer were considered as error factors during the experiment. Then the picket fence effect, leakage, and exponential window function were considered as candidate error factors during the digital signal processing. Finally, methods to reduce errors are suggested.

E-Business and Simulation

  • Park, Sung-Joo
    • Proceedings of the Korea Society for Simulation Conference
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    • 2001.10a
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    • pp.9-10
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    • 2001
  • Simulation has been evolved with the advance of computer and technique of modeling application systems. Early simulations were numerical analysis of engineering models known as continuous simulation, analysis of random events using various random number generators thus named as Monte Carlo simulation, iud analysis o(\\\\`queues which are prevalent in many real world systems including manufacturing, transportation, telecommunication. Discrete-event simulation has been used far modeling and analyzing the systems with waiting lines and inefficient delays. These simulations, either discrete-event, continuous, or hybrid, have played a key role in industrial age by helping to design and implement the efficient real world systems. In the information age which has been brought up by the advent of Internet, e-business has emerged. E-business, any business using Internet, can be characterized by the network of extended enterprises---extended supply and demand chains. The extension of value chains spans far reaching scope in business functions and space globally. It also extends to the individual customer, customer preferences and behaviors, to find the best service and product fit for each individual---mass customization. Simulation should also play a key role in analyzing and evaluating the various phenomena of e-business where the phenomena can be characterized by dynamics, uncertainty, and complexity. In this tutorial, applications of simulation to e-business phenomena will be explained and illustrated. Examples are the dynamics of new economy, analysis of e-business processes, virtual manufacturing system, digital divide phenomena, etc. Partly influenced by e-business, a new trend of simulation has emerged called agent-based simulation, Agent-based simulation is a technique of simulation using software agent that have autonomy and proactivity which are useful in analyzing and integrating numerous individual customer's behavior. One particular form of agent-based simulation is swarm. This tutorial concludes with the illustration of swarm or swarm Intelligence applied to various e-business applications, and future directions and implications of this new trend of simulation.

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Development of the Integrated Fuel Cell Monitoring System (통합 연료전지모니터링 시스템 개발)

  • KIM, HYUNJUN;YEOM, SANGCHUL;AHN, BYUNGKI;KIM, SAEHOON;KUM, YEONGBEOM
    • Transactions of the Korean hydrogen and new energy society
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    • v.26 no.3
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    • pp.241-246
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    • 2015
  • The interest of New Renewable Energy is increasing globally because of the increment of the uncertainty for the energy's supply and demand, and the increment of the frequency in weather anomaly and its damages. One of the New Renewable Energies, Hydrogen receives attention as the future energy that can deal with global environment regulation. Fuel Cell Electric Vehicle (FCEV) is an environment-friendly vehicle that uses Hydrogen as fuel. The electric power for FCEV is generated by chemical reaction with Oxygen from the air and Hydrogen. Hyundai Motor Company (HMC) has developed a proprietary fuel cell system since 2005. In 2012, HMC is the first car maker that mass-produces the ix35 FCEV to the worldwide such as North America, Europe, etc. In order to develop and improve the FCEV technology, data acquisition and analysis of the driving vehicle information is essential. Therefore, the monitoring system is developed, which is consist of datalogger, Automatic Vehicle Location (AVL) server and main server. Especially, WCDMA technology is integrated into the system which enables the data analysis without any restriction of time and region. The main function of the system is the analysis of the driving pattern and the component durability, and the safety monitoring. As a result, ix35 FCEV has successfully developed by using the developed monitoring system. The system is going to take an advantage of development in the future FCEV technology.

Design and Experimental Evaluation of a Robust Force Controller for a 6-Link Electro-Hydraulic Manipulator via H$_{\infty}$ Control Theory

  • Ahn, Kyoung-Kwan;Lee, Byung-Ryong;Yang, Soon-Yong
    • Journal of Mechanical Science and Technology
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    • v.17 no.7
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    • pp.999-1010
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    • 2003
  • Uninterrupted power supply has become indispensable during the maintenance task of active electric power lines as a result of today's highly information-oriented society and increasing demand of electric utilities. This maintenance task has the risk of electric shock and the danger of falling from high place. Therefore it is necessary to realize an autonomous robot system using electro-hydraulic manipulators because hydraulic manipulators have the advantage of electric insulation and power/mass density. Meanwhile an electro-hydraulic manipulator using hydraulic actuators has many nonlinear elements, and its parameter fluctuations are greater than those of an electrically driven manipulator. So it is relatively difficult to realize not only stable contact work but also accurate force control for the autonomous assembly tasks using hydraulic manipulators. In this paper, the robust force control of a 6-link electro-hydraulic manipulator system used in the real maintenance task of active electric lines is examined in detail. A nominal model for the system is obtained from experimental frequency responses of the system, and the deviation of the manipulator system from the nominal model is derived by a multiplicative uncertainty. Robust disturbance observers for force control are designed using this information in an H$\_$$\infty$/ framework, and implemented on the two different setups. Experimental results show that highly robust force tracking by a 6-link electro-hydraulic manipulator could be achieved even if the stiffness of environment and the shape of wall change.

Development of Contact-Type Thickness Measurement Machine using LVDT Sensors (LVDT센서를 이용한 접촉식 두께자동측정기 개발)

  • Shin, Ki-Yeol;Hwang, Seon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.4
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    • pp.151-159
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    • 2015
  • In this study, we developed an automated contact-type thickness measurement machine that continuously and precisely measures the thickness of a PCB module product using multi-LVDT sensors. The system contains a measurement part to automatically measure the thickness in real time according to the set conditions with an alignment supply unit and unloading unit to separate OK and NG products. The sensors were calibrated before assembly in the measuring machine, and precision and accuracy performance tests were also performed to reduce uncertainty errors in the measurement machine. In the calibration test, the precision errors of the LVDT sensor were determined to be $1-3{\mu}m$ as 0.1% at the measuring range. A measurement error of 0.8 mm and 1.0 mm thickness test standards were found to be $1{\mu}m$ and $4{\mu}m$, and the standard deviations of two 1.0 mm products were measured as $14{\mu}m$ and $8{\mu}m$, respectively. In the measurement system analysis, the accuracies of test PCB standards were found to be $2{\mu}m$ and $3{\mu}m$, respectively. From the results of gage repeatability and reproducibility (R & R) crossed, we found that the machine is suitable for the measurement and process control in the mass production line as 7.92% of total gage R & R and in seven distinct categories. The maximum operating speed was limited at 13 pcs/min, showing a value good enough to measure.

A Study on the Attraction Factors of the Enetertainment Industry (엔터테인먼트산업의 어트랙션 요소에 관한 연구)

  • 이호숭
    • Archives of design research
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    • v.15 no.2
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    • pp.59-70
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    • 2002
  • The psychological system of human beings has gone through changes from material satisfaction to spiritual satisfaction. That is, $\ulcorner$From real goods to feel goods$\lrcorner$: much attention is not paid to physical consumption of real products but to consumption of time containing information value such as services capable of enriching and entertaining life. Entertainment is a cultural industry based on mass consumption culture. In this context, this research is designed to look into the entertainment tendency of the industrial areas and to take a look at various forms of attraction serving as the factor of absorption to users. The study indicates that the moderns impose much value on invisible goods such as experience. And the most popularized method is to appeal to clients for sensory interaction by presenting the experience of joy. Entertainment in a true sense is generated on the basis of creativity, which is a product of intuition and efforts directed toward the understanding of emotional ties with the general public characterized by uncertainty.

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Study on Representation of Pollutants Delivery Process using Watershed Model (수질오염총량관리를 위한 유역모형의 유달 과정 재현방안 연구)

  • Hwang, Ha Sun;Rhee, Han Pil;Lee, Sung Jun;Ahn, Ki Hong;Park, Ji Hyung;Kim, Yong Seok
    • Journal of Korean Society on Water Environment
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    • v.32 no.6
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    • pp.589-599
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    • 2016
  • Implemented since 2004, TPLC (Total Pollution Load Control) is the most powerful water-quality protection program. Recently, uncertainty of prediction using steady state model increased due to changing water environments, and necessity of a dynamic state model, especially the watershed model, gained importance. For application of watershed model on TPLC, it needs to be feasible to adjust the relationship (mass-balance) between discharged loads estimated by technical guidance, and arrived loads based on observed data at the watershed outlet. However, at HSPF, simulation is performed as a semi-distributed model (lumped model) in a sub-basin. Therefore, if the estimated discharged loads from individual pollution source is directly entered as the point source data into the RCHRES module (without delivery ratio), the pollutant load is not reduced properly until it reaches the outlet of the sub-basin. The hypothetic RCHRES generated using the HSPF BMP Reach Toolkit was applied to solve this problem (although this is not the original application of Reach Toolkit). It was observed that the impact of discharged load according to spatial distribution of pollution sources in a sub-basin, could be expressed by multi-segmentation of the hypothetical RCHRES. Thus, the discharged pollutant load could be adjusted easily by modification of the infiltration rate or characteristics of flow control devices.