• Structural Engineering and Mechanics
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• v.18 no.4
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• pp.517-539
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• 2004

Many types of passive control devices have been recognized as effective tools for improving the seismic resistance of structures. A lot of past research has been carried out to study the response of structures equipped with energy-absorbing devices by assuming that the behavior of the beam-column systems are linearly elastic. However, linear theory may not be adequate for beams and columns during severe earthquakes. This paper presents the results of research on the nonlinear responses of structures with and without added passive devices under earthquakes. A new material model based on the plasticity theory and the two-surface model for beams and columns under six components of forces is proposed to predict the nonlinear behavior of beam-column systems. And a new nonlinear beam element in consideration of shear deformation is developed to analyze the beams and columns of a structure. Numerical results reveal that linear assumption may not be appropriate for beams and columns under seismic loadings, especially for unexpectedly large earthquakes. Also, it may be necessary to adopt nonlinear beam elements in the analysis and design process to assure the safety of structures with or without the control of devices.

• Proceedings of the Technology Innovation Conference
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• 1997.07a
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• pp.57-82
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• 1997

This paper empirically examines various personal characteristics and preferences of HRM (Human Resorce Mamagement) systems using data from 968 R&D professionals in 9 private R&D organizations. It identifies different patterns of reward and career development needs associated with 4 types of R&D professionals, who are categorized by personal characteristics: personality and attitude. A productive leader type shows active personal traits (which encompass high scores of need for achievement, risk-taking propensity, tolerance for ambiguity, and self-efficacy) and positive attitudes (which include high scores of job satisfaction, organizational commitment, and low scores of turnover intention), while a cynical bystander type exhibits passive personal traits and negative attitudes toward a job. A passive adapter, who has passive personal characteristics but positive attitudes, and a frustrated champion, who is active in personality but negative in current job attitude, lie in between them. The results reveal that: 1) These four different types of R&D professionals show differences in their education, age and tenure level, and technical performance. 2) They have different career orientations and problem solving styles. 3) They also exhibit different preferences in performance appraisal criteria and rater, and reward structures. Based on these findings, this study suggests a contingent type of human resource management in terms of selection and staffing of R&D professionals, performance appraisal, incentive systems, and career development plans.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.4
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• pp.1-7
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• 2011

In this paper, we design rectifing circuits at 910MHz, which is used for passive RFID system, for wireless power transmission system by using two types of schottkey diodes HSMS_2822 and HSMS 2852, and the RF-DC conversion efficiencies for the curcuits are compared and analyzed in terms of input power and load resistance. When the input power is -20 to 17dBm, the conversion efficiency for HSMS_2852 is larger than in case of HSMS_2822. The output voltage and current at the load of the fabricated rectifying circuit are measured through a dipole antenna when input power is transmitted by a RFID reader and the diatance varies. The measured ouput volatge and current for the distance of 50cm are 2.5V and 5.75mA.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.4
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• pp.189-197
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• 2003

The problem of designing a parallel feedforward compensator (PFC) is considered for a class of non-square linear systems such that the closed-loop system is strictly passive. If a given square system has (vector) relative degree one and is weakly minimum phase, the system can be rendered passive by a state feedback. However, when the system states are not always measurable and the given output is considered, passivation (i.e. rendering passive) of a non-minimum phase system or a system with high relative degree cannot be achieved by any other methodologies except by using a PFC. To passivate a non-square system we first determine a squaring gain matrix and design a PFC such that the composite system has relative degree one and is minimum phase. Then the system is rendered strictly passvie by a static output feedback law. Necessary and sufficient conditions for the existence of the PFC and the squaring gain matrix are given by the static output feedback formulation, which enables to utilize linear matrix inequality (LMI). As an application of the scheme, an alternative way of replacing the role of velocity measurements is provided for the PD-control law of a convey-crane system.

• The Journal of Information Systems
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• v.32 no.4
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• pp.69-94
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• 2023

Purpose Social networking service (SNS) platforms employ distinct networking strategies to meet the varying needs of their users, resulting in divergent sets of technological functionalities offered by each platform. Consequently, unique features on various SNSs give rise to distinct social issues. Moreover, the available technical coping mechanisms for users vary significantly across platforms. Design/methodology/approach Therefore, this study analyzes the factors affecting technical coping intention based on technical functions of SNSs for users exposed to cybercrime, such as sexual harassment. We divide coping intention into active and passive coping intention. Furthermore, this research focuses on trust as an antecedent of coping intention and verifies how human and system-like trust affects two coping intentions in different directions. Findings Findings reveal that system-like trust significantly affects both active and passive coping intention as a belief in whether the technology will work properly. However, in the case of human-like trust, trust in the platform provider was found to negatively affect passive coping, which is considered unsocialized behavior on SNS platforms. Therefore, both human-like and system-like trust for the platform must be appropriately applied to cope with the problem while activating the platform.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.879-884
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• 2007

Flywheel energy storage systems have advantages over other types of energy storage devices in such aspects as unlimited charge/discharge cycles and environmental friendliness. In this paper we propose a millimeter scale flywheel energy storage device. The flywheel is supported by a pair of passive magnetic bearings and rotated by a toroidally wound electric motor/generator. The geometry of the bearings is optimized for the maximum dynamic performance.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.99-104
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• 1989

A practical filter is suggested for ground-Dasea missile tracking in a capture guidance mode, utilizing angle-only measurements from a passive sensor and its performance is evaluated by a realistic system simulation study. Also suggested is a missile acceleration model that provides inputs to the filter. The suggested filter has a decoupled structure of independent azimuth and elevation channels with efficiency in commutation time and memory requirements.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.199-202
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• 1999

In this paper, a possibility of building various types of RF passive components using the silicon micromachining technique has been examined with special emphasis on the wireless and mobile communication applications. Silicon micromachining technique is compatible with conventional silicon IC process and could provide a possibility of integrating base-band signal processing units and RF passive and active circuit components all in one silicon wafer rendering implementation of system-on-chip paradigm for future mobile and wireless communication systems.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.184-187
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• 2003

To solve the problems of operating passive mine drainage treatment systems, the In Adit Sulfate Reducing System(IASRS) was suggested. By placing the SAPS inside the adit, the condition of constant temperature of 10~15$^{\circ}C$ can be maintained. The experiments using the models made up by four sections showd good efficiencies in pH control and metal removal rate, but showed still low sulfate removal rate of about 30% with high COB in the begining of the operation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.11
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• pp.2266-2268
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• 2009

In this paper, a simple method of angle velocity estimation is presented for a passive dynamic biped robot. The estimation problem is not an easy task because its dynamic model is a hybrid system involved with an impact condition. Instead of designing a complex observer for hybrid systems we simply utilize the impact condition to reset the initial condition of the high-pass filter when the non-support leg hits the slope. The approach has been verified by simulation results.