• Earthquakes and Structures
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• v.3 no.5
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• pp.749-766
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• 2012

Structural control through integration of passive damping devices within the building structure has been increasingly implemented internationally in the last years and has proven to be a most promising strategy for earthquake safety. In the present paper an alternative configuration of an innovative energy dissipation mechanism that consists of slender tension only bracing members with closed loop and a hysteretic damper is investigated in its dynamic behavior. The implementation of the adaptable dual control system, ADCS, in frame structures enables a dual function of the component members, leading to two practically uncoupled systems, i.e., the primary frame, responsible for the normal vertical and horizontal forces and the closed bracing-damper mechanism, for the earthquake forces and the necessary energy dissipation. Three representative international earthquake motions of differing frequency contents, duration and peak ground acceleration have been considered for the numerical verification of the effectiveness and properties of the SDOF systems with the proposed ADCS-configuration. The control mechanism may result in significant energy dissipation, when the geometrical and mechanical properties, i.e., stiffness and yield force of the integrated damper, are predefined. An optimum damper ratio, DR, defined as the ratio of the stiffness to the yield force of the hysteretic damper, is proposed to be used along with the stiffness factor of the damper's- to the primary frame's stiffness, in order for the control mechanism to achieve high energy dissipation and at the same time to prevent any increase of the system's maximum base shear and relative displacements. The results are summarized in a preliminary design methodology for ADCS.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.204-209
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• 2003

Recently, The TCN(Train Communication Network} as the distributed control systems for electric vehicles, which is the international standard of the intra vehicle communication, actively recognizes variations and supports reconfiguration of the train network when a vehicle is separated or recombined. The technique of reconfiguration to take variety and interoperability of a vehicle constitution is used when the vehicle constitution is changed. At the time, each node making up vehicle network shares the information about the variation of vehicle constitutions and the state of nodes. In the hierarchical TCN structure, an exchange of data becomes available as a work to transmit information between components is performed at the node playing a role of gateway. This paper proposes a protocol to transmit the information of the train reconfiguration. The protocol gives an application to renew a list for transmitting information and to perform the transmission that can guarantee periodic and non-periodic data transmission between nodes when the network nodes changed by a variation of the network state are reconfigured. If use this protocol, can use functions that are offered in the electric railcar at the same time that composition of vehicles is completed without delay. And when driver of the electric railcar inspect before running of vehicles, can confirm state of vehicles visually through monitor in driver's room.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2126-2128
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• 2001

This paper suggests that the immune network algorithm based on fuzzy set can effectively be used in tuning of a PID controller for multivariable process or nonlinear process. The artificial immune network always has a new parallel decentralized processing mechanism for various situations, since antibodies communicate to each other among different species of antibodies/B-cells through the stimulation and suppression chains among antibodies that from a large-scaled network. In addition to that, the structure of the network is not fixed, but varies continuously. On the other hand, a number of tuning technologies have been considered for the tuning of a PID controller. As a less common method, the fuzzy and neural network or its combined techniques are applied. However, in the case of the latter, yet, it is not applied in the practical field, in the former, a higher experience and technology is required during tuning procedure. Along with these, this paper used the fuzzy set in order that the stimulation and suppression relationship between antibody and antigen can be more adaptable controlled against the external condition, including noise or disturbance of plant. The immune network based on fuzzy set suggested here is applied for the PID controller tuning of multivariable process with two inputs and one output and is simulated.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.2
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• pp.127-134
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• 2004

In this paper, human motor behaving model based sensory motor coordination(SMC) algorithm is implemented on robotic grasping task. Compare to conventional SMC models which connect sensor to motor directly, the proposed method used biologically inspired human behaving system in conjunction with SMC algorithm for fast grasping force control of robot arm. To characterize various grasping objects, pressure sensors on hand gripper were used. Measured sensory data are simultaneously transferred to perceptual mechanism(PM) and long term memory(LTM), and then the sensory information is forwarded to the fastest channel among several information-processing flows in human motor system. In this model, two motor learning routes are proposed. One of the route uses PM and the other uses short term memory(STM) and LTM structure. Through motor learning procedure, successful information is transferred from STM to LTM. Also, LTM data are used for next moor plan as reference information. STM is designed to single layered perception neural network to generate fast motor plan and receive required data which comes from LTM. Experimental results showed that proposed method can control of the grasping force adaptable to various shapes and types of greasing objects, and also it showed quicker grasping-behavior lumining time compare to simple feedback system.

• Journal of the Korea Institute of Building Construction
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• v.16 no.1
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• pp.87-96
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• 2016

More than half of Korea's urban population currently lives in multi-unit dwellings. This particular residence structure inevitably positions the living spaces of residents in close proximity to one another. Because of this proximity, the sounds of a particular household will transfer to other residents' units creating conflict between tenants. Efforts to alleviate this problem have been made in both the public and private sector. A prominent method of noise analysis between living units has been to make an actual sound measurement and obtain qualitative measurements from questionnaires. Although this method has been most widely used, such analysis requires a large amount of human effort and time. In addition, the questionnaire method fails to provide the objective information needed to accurately assess the noise situation. To overcome the inadequacies of this previous method, this study seeks to evaluate the applicability of an acoustic simulation method. Three types of living noises were analyzed to assess the noise levels passed between multi-unit dwellings. The acoustic simulation method was found to be more economical, efficient, and adaptable in information processing. The results of this study can be further applied to design and control living-noise through procedures such as acoustic absorption or space redesign.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1921-1936
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• 2017

Internet of Thing (IoT) and NFC (Near Field Communication) have got a good adaptable structure that it can be easily combined with any wireless network. Since IoT/NFC can be used to communicate wirelessly with all the transactions that can be done remotely without any physical connections. In this paper, we propose an enhanced secure IoT/NFC protocol based on LTE network that enhances the original security level provided by the LTE. Our approach is new in a sense that it covers LTE in contrast to old networks like GSM and 3G, which substantially treated in the literature. Moreover, both GSM and 3G have several drawbacks when they are combined with the NFC technology, which has potential weakness in confidentiality, integrity, and authentication. Hence our new approach will resolve the security of the new LTE system. We expect that our protocol will result in new secure applications for the smart phone markets.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.573-574
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• 2006

The planarization technology of Chemical-mechanical polishing(CMP), used for the manufacturing of multi-layer various material interconnects for Large-scale Integrated Circuits (LSI), is also readily adaptable as an enabling technology in MicroElectroMechanical System (MEMS) fabrication, particularly polysilicon surface micromachining. However, general LSI device CMP has partly distinction aspects, the pattern scale and material sorts in comparison with MEMS CMP. This study performed preliminary CMP tests to identify slurry characteristic used in general IC device. The experiment result is possible to verify slurry characteristic in MEMS structure material.

• Geomechanics and Engineering
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• v.13 no.6
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• pp.997-1010
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• 2017

The black box model is a relatively new option for nonlinear dynamic system identification. It can be used for prediction problems just based on analyzing the input and output data without considering the changes of the internal structure. In this paper, a black box model was presented to solve unconstrained overlying strata movement problems in coal mine production. Based on the black box theory, the overlying strata regional system was viewed as a "black box", and the black box model on overburden strata movement was established. Then, the rock mechanical properties and the mining thickness and mined-out section area were selected as the subject and object respectively, and the influences of coal mining on the overburden regional system were discussed. Finally, a corrected method for height prediction of the fractured zone was obtained. According to actual mine geological conditions, the measured geological data were introduced into the black box model of overlying strata movement for height calculation, and the fractured zone height was determined as 40.36 m, which was comparable to the actual height value (43.91 m) of the fractured zone detected by Double-block Leak Hunting in Drill. By comparing the calculation result and actual surface subsidence value, it can be concluded that the proposed model is adaptable for height prediction of the fractured zone.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.1
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• pp.145-164
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• 2023

Cloud computing offers a platform that is both adaptable and scalable, making it ideal for outsourcing data for sharing. Various organizations outsource their data on cloud storage servers for availing management and sharing services. When the organizations outsource the data, they lose direct control on the data. This raises the privacy and security concerns. Cryptographic encryption methods can secure the data from the intruders as well as cloud service providers. Data owners may also specify access control policies such that only the users, who satisfy the policies, can access the data. Attribute based access control techniques are more suitable for the cloud environment as they cover large number of users coming from various domains. Multi-authority attribute-based encryption (MA-ABE) technique is one of the propitious attribute based access control technique, which allows data owner to enforce access policies on encrypted data. The main aim of this paper is to comprehensively survey various state-of-the-art MA-ABE schemes to explore different features such as attribute and key management techniques, access policy structure and its expressiveness, revocation of access rights, policy updating techniques, privacy preservation techniques, fast decryption and computation outsourcing, proxy re-encryption etc. Moreover, the paper presents feature-wise comparison of all the pertinent schemes in the field. Finally, some research challenges and directions are summarized that need to be addressed in near future.

• Advances in nano research
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• v.13 no.4
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• pp.351-368
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• 2022

Recently, promising structural technologies like multi-function, ultra-load bearing capacity and tailored structures have been put up for discussions. Finite Element (FE) modelling is probably the best-known option capable of treating these superior properties and multi-domain behavior structures. However, advanced materials such as Functionally Graded Material (FGM) and nanocomposites suffer from problems resulting from variable material properties, reinforcement aggregation and mesh generation. Motivated by these factors, this research proposes a unified shape function for FGM, nanocomposites, graded nanocomposites, in addition to traditional isotropic and orthotropic structural materials. It depends not only on element length but also on the beam's material properties and geometric characteristics. The systematic mathematical theory and FE formulations are based on the Timoshenko beam theory for beam structure. Furthermore, the introduced element achieves C1 degree of continuity. The model is proved to be convergent and free-off shear locking. Moreover, numerical results for static and free vibration analysis support the model accuracy and capabilities by validation with different references. The proposed technique overcomes the issue of continuous properties modelling of these promising materials without discarding older ones. Therefore, introduced benchmark improvements on the FE old concept could be extended to help the development of new software features to confront the rapid progress of structural materials.