• Journal of Electrical Engineering and Technology
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• v.2 no.3
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• pp.408-412
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• 2007

It is almost impossible to secure the reproductibility and stability of a commercial Thick-Film Metal Oxide Semiconductor Gas Sensor since it is very difficult to keep the consistency of the manufacturing environment. Thus it is widely known that the general Semiconductor-Oxide Gas Sensors are not appropriate for precise measurement systems. In this paper, the output characteristic analyzer of the various Thick-Film Metal Oxide Semiconductor Gas Sensors that are used to recognize the air quality within an automobile are proposed and examined. The analyzed output characters in a normal air chamber are grouped by sensor ranks and used to fill out the characteristic table of the Thick-Film Metal Oxide Semiconductor Gas Sensors. The characteristic table is used to determine the rank of the sensor that is equipped in the current air cleaner system of an automobile. The proposed air control system can also adapt the on-demand operation that recognizes the history of the passenger's manual-control.

• Smart Structures and Systems
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• v.24 no.5
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• pp.641-648
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• 2019

The authors investigate the feasibility of applying a vision-based displacement-measurement technique in the characterization of a SMA damper recently introduced in the literature. The experimental campaign tests a steel frame on a uni-axial shaking table driven by sinusoidal signals in the frequency range from 1Hz to 5Hz. Three different cameras are used to collect the images, namely an industrial camera and two commercial smartphones. The achieved results are compared. The camera showing the better performance is then used to test the same frame after its base isolation. U-shaped, shape-memory-alloy (SMA) elements are installed as dampers at the isolation level. The accelerations of the shaking table and those of the frame basement are measured by accelerometers. A system of markers is glued on these system components, as well as along the U-shaped elements serving as dampers. The different phases of the test are discussed, in the attempt to obtain as much possible information on the behavior of the SMA elements. Several tests were carried out until the thinner U-shaped element went to failure.

• Journal of IKEEE
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• v.24 no.4
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• pp.991-997
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• 2020

Reinforcement learning has been applied mainly in sequential decision-making problems. Especially in recent years, reinforcement learning combined with neural networks has brought successful results in previously unsolved fields. However, reinforcement learning using deep neural networks has the disadvantage that it is too complex for immediate use in the field. In this paper, we implemented path planning algorithm for mobile robots using Q-learning, one of the easy-to-learn reinforcement learning algorithms. We used real-time Q-learning to update the Q-table in real-time since the Q-learning method of generating Q-tables in advance has obvious limitations. By adjusting the exploration strategy, we were able to obtain the learning speed required for real-time Q-learning. Finally, we compared the performance of real-time Q-learning and DQN.

• Journal of Information Display
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• v.13 no.1
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• pp.21-30
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• 2012

Active-matrix electrophoretic display (AMEPD) is commonly used for the applications of smart handheld reading devices such as e-books and e-news. This paper presents a new reduced waveform lookup table storage method that reduces the associated lookup table by approximately 2n (n is the number of gray levels employed) times the conventional one. The paper also proposes a driving method for image display. The method provides high-speed performance for image display and also effectively eliminates the image residue, achieving high image quality. The prototyped controller was connected to a 6" AMEPD panel, whose excellent display quality demonstrated the effectiveness of the proposed controller design.

• Smart Structures and Systems
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• v.14 no.4
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• pp.501-516
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• 2014

The rocking pier system (RPS) allows the columns to rock on beam or foundation surfaces during the attacks of a strong earthquake. Literatures have proved that seismic energy dissipated by the RPS through the column impact is limited. To enhance the energy dissipation capacity of a RPS bridge substructure, frictional hinge dampers (FHDs) were installed and evaluated by shaking table tests. The supplemental FHDs consist of two brass plates sandwiched by three steel plates. The strategy of self-centering design is to isolate the seismic energy by RPS at the columns and then dissipate the energy by FHDs at the bridge deck. Component tests of FHD were first conducted to verify the friction coefficient and dynamic characteristic of the FHDs. In total, 32 shaking table tests were conducted to investigate parameters such as wave forms of the earthquake (El Centro 1940 and Kobe 1995) and normal forces applied on the friction dampers. An analytical model was also proposed to compare with the tested damping of the bridge sub-structure with or without FHDs.

• Smart Structures and Systems
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• v.4 no.2
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• pp.153-169
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• 2008

The use of pre-tensioned shape memory alloy (SMA) wires to retrofit historic masonry structures is investigated. A small wall, serving as a prototype masonry specimen, is constructed to undergo a series of shaking-table tests. It is first studied in its original state, and its dynamic characteristics (in terms of modal frequencies) are extracted from the recorded signals. The results are then compared with those obtained when an increasing number of couples of pre-stressed SMA wires are introduced in the specimen to link the bricks together. A three-dimensional finite element model of the specimen is developed and calibrated according to the modal parameters identified from each experimental test (with and without SMA wires). The calibration process is conducted by enhancing the masonry mechanical behaviour. The results and the effectiveness of the approach are presented.

• Smart Structures and Systems
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• v.15 no.3
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• pp.863-879
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• 2015

This paper experimentally investigates the effectiveness and applicability of the time delay control (TDC) algorithm, which is simple and robust to unknown system dynamics and disturbance, for an active mass damper (AMD) system to mitigate the excessive vibration of a building structure. To this end, the theoretical background including the mathematical formulation of the control system is first described; and then, a thorough experimental study using a shaking table system with a small-scale three-story building structural model is conducted. In the experimental tests, the performance of the proposed control system is examined by comparing its structural responses with those of the uncontrolled system in the free vibration and forced vibration cases. It is clearly verified from the test results that the TDC algorithm embedded AMD system can effectively reduce the structural response of the building structure.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.715-724
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• 2017

Today all kinds of smart devices are being developed with various researches on wearable devices that support smart computing on the human body. Skin diseases continue to rise including freckles, pimples, atopy, and scalp trouble due to the environmental and genetic factors, and people pay bigger medical bills to treat their skin diseases. There is thus a need to develop a smart-phone or table-based smart healthcare imaging system of high portability and diagnostic accuracy capable of analyzing and managing various skin problems related to skin care. This study proposed an integrated system combining the Smart Mi Band, a wearable device using moisture and UV sensors based on IoT, on the hardware part with the sensor information monitoring software.

• Journal of the Korea Convergence Society
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• v.9 no.2
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• pp.165-170
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• 2018

The purpose of this study is to recognize the necessity of smart furniture for single - person households and to suggest final design. It is assumed that smart furniture that meets the demand can be released in the future. To this end, we intend to solve the needs of the smart technology of the subject through in-depth interviews and persona establishment through demand research. Currently, the number of single-person households is expected to increase steadily and become the most important form of household composition in the future. In the future, it will be analyzed based on the in-depth interview after the target selection for the target needs research. Then, after insights are gathered through in-depth interviews, we apply the applicable smart technology to create the expected scenarios and draw conclusions about how smart furniture will function in the future.

• Journal of Korean Society of Disaster and Security
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• v.13 no.1
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• pp.25-39
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• 2020

Despite the global promotion of Smart City, there is currently no standard for smart water grid development, and it is not possible to judge the success of Smart City. There is a clear need to establish the requirements and goals of the Smart Water Grid and accurately diagnose and improve the limitations and problems of the existing Smart Water Grid. For this purpose, it is very important to use the index suitable for Smart Water Grid goals. In this study, we developed Smart Water Grid Index which can be used to evaluate the target measurement and attainment of Smart Water Grid and can be utilized based on the implementation plan for Smart Water Grid in the future. Through the development of the Smart Water Grid Key Performance Index (SWG KPI), we will lay the groundwork for continuous capacity evaluation of the Smart Water Grid and improve the reliability of the Index. It is expected that it will be possible to prepare and evaluate a Challenge Evaluation Card for the planned Smart Water Grid by providing an evaluation table for grid competency evaluation.