• Title/Summary/Keyword: LED sensor

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Theoretical Aspects of PTC Thermistors

  • Cho, Sang-Hee
    • Journal of the Korean Ceramic Society
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    • v.43 no.11 s.294
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    • pp.673-679
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    • 2006
  • The discovery of ferroelectric barium titanate (BaTiO$_3$) in 1942 began the present era of dielectrics-based electronic ceramics. Ferroelectric barium titanate has a high dielectric constant and after the recognition of BaTiO$_3$ as a new ferroelectric compound, various attractive electrical properties have been extensively studied and reported. Since then, pioneering work on valence-compensated semiconduction led to the discovery of the positive temperature coefficient (PTC) of the resistance effect found in doped BaTiO$_3$. Significant progress has since followed with respect to understanding the PTC phenomena, advancing materials capabilities, and developing devices for sensor and switching applications. In this paper, the theoretical aspects of the various PTC models are discussed and the future trends of practical applications for PTC devices are briefly mentioned.

Application of Controller Area Network to Humanoid Robot (휴머노이드 로봇에 대한 CAN(Controller Area Network) 적용)

  • Ku, Ja-Bong;Huh, Uk-Youl;Kim, Jin-Geol
    • Proceedings of the KIEE Conference
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    • 2004.05a
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    • pp.77-79
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    • 2004
  • Because robot hardware architecture generally is consisted of a few sensors and motors connected to the central processing unit, this type of structure is led to time consuming and unreliable system. For analysis, one of the fundamental difficulties in real-time system is how to be bounded the time behavior of the system. When a distributed control network controls the robot, with a central computing hub that sets the goals for the robot, processes the sensor information and provides coordination targets for the joints. If the distributed system supposed to be connected to a control network, the joints have their own control processors that act in groups to maintain global stability, while also operating individually to provide local motor control. We try to analyze the architecture of network-based humanoid robot's leg part and deal with its application using the CAN(Controller Area Network) protocol.

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2-Dimensional colloidal micropatterning of cholesteric liquid crystal microcapsules for temperature-responsive color displays

  • Lee, Woo Jin;Kim, Bohyun;Han, Sang Woo;Seo, Minjeong;Choi, Song-Ee;Yang, Hakyeong;Kim, Shin-Hyun;Jeong, Sohee;Kim, Jin Woong
    • Journal of Industrial and Engineering Chemistry
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    • v.68
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    • pp.393-398
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    • 2018
  • This work offers a promising approach for development of a temperature-responsive colorimetric display platform. For this purpose, uniform thermochromic microcapsules consisting of a cholesteric liquid crystal (CLC) core and a thin polyurethane shell layer were fabricated by conducting in-situ condensation polymerization at the interface of monodisperse CLC-in-water emulsion drops. Colloidal packing-driven microcapsule registry led to exact 2-dimensional positioning of CLC microcapsules into a holes-patterned flexible film stencil. Furthermore, we showed that the designated registry of different color types of CLC microcapsules on the stencil enabled development of a microwriting display technology capable of reversible text representation according to temperature change.

A Fall Detection Technique using Features from Multiple Sliding Windows

  • Pant, Sudarshan;Kim, Jinsoo;Lee, Sangdon
    • Smart Media Journal
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    • v.7 no.4
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    • pp.79-89
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    • 2018
  • In recent years, falls among elderly people have gained serious attention as a major cause of injuries. Falls often lead to fatal consequences due to lack of prompt response and rescue. Therefore, a more accurate fall detection system and an effective feature extraction technique are required to prevent and reduce the risk of such incidents. In this paper, we proposed an efficient feature extraction technique based on multiple sliding windows and validated it through a series of experiments using supervised learning algorithms. The experiments were conducted using the public datasets obtained from tri-axial accelerometers. The results depicted that extraction of the feature from adjacent sliding windows led to high accuracy in supervised machine learning-based fall detection. Also, the experiments conducted in this study suggested that the best accuracy can be achieved by keeping the window size as small as 2 seconds. With the kNN classifier and dataset from wearable sensors, the experiments achieved accuracy rates of 94%.

Simple image artifact removal technique for more accurate iris diagnosis

  • Kim, Jeong-lae;Kim, Soon Bae;Jung, Hae Ri;Lee, Woo-cheol;Jeong, Hyun-Woo
    • International journal of advanced smart convergence
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    • v.7 no.4
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    • pp.169-173
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    • 2018
  • Iris diagnosis based on the color and texture information is one of a novel approach which can represent the current state of a certain organ inside body or the health condition of a person. In analysis of the iris images, there are critical image artifacts which can prevent of use interpretation of the iris textures on images. Here, we developed the iris diagnosis system based on a hand-held typed imaging probe which consists of a single camera sensor module with 8M pixels, two pairs of 400~700 nm LED, and a guide beam. Two original images with different light noise pattern were successively acquired in turns, and the light noise-free image was finally reconstructed and demonstrated by the proposed artifact removal approach.

Sewing-enabled electric button for smart fabric

  • Lee, Kang-Ho;Lee, Dongkyu;Lee, Yong-Goo;Kwon, Ohwon
    • Journal of Sensor Science and Technology
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    • v.30 no.2
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    • pp.67-70
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    • 2021
  • A new button-shaped electrical device was developed for a smart fabric. This electric button can be sewn anywhere on the garment, similar to a traditional button fastener. t not only performs a decorative function but also makes the fabric suitable for use in Internet of Things (IoT) applications. It has metallic through-holes such that it can be fastened onto a fabric by conductive sewing threads. When threaded through metallic holes, the button can communicate with the external device by transmitting and receiving data. In addition, it adds specific functions by stacking a detachable application layer on the base layer. It is robust to frequent washing, and thus has excellent repeatability for use as an IoT device. The feasibility of the electric button was successfully demonstrated by its ability to identify the physical activities of walking and running, monitoring ambient temperature, and turning on LED lights.

Vibration Control of Moving Structures by Neural Network (신경회로망을 이용한 구조물의 운동 중 진동의 제어에 관한 연구)

  • Lee, Sin-Young;Jeong, Heon-Sul
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.9
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    • pp.138-148
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    • 1996
  • In moving structures such as robots and feeders of production lines, vibrations may not be ignored. Recently it becomes a big problem to control the vibration in a motion because moving structures are in higher speed, larger size and lighter weight. In this study a nonlinear system was model- led and identified by using neural networks and the vibration in motions was controlled actively by using a neural network controller. To investigate vilidity of this method, an experimental apparatus was made and tested. The model was composed of a DC servomotor, a carrier and a flexible plate. Its motion was measured by a gap sensor and an encoder. Trapezoidal, cycloid and trapecloid type trajectories were used in this exper- riment. Computer simulations and experiments weredone for each trajectory.

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A Smart Fire Detector System for Fire Prevention (화재 예방을 위한 스마트 화재 감지기 시스템)

  • Park, Cha-Hun;Kang, Yun-ho;Jang, Min-sung;Seo, Hee-jun;Kim, Yun-min
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2022.01a
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    • pp.293-294
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    • 2022
  • 본 프로젝트에서는 화재 발생 시 발견하기 어려운 곳이나 화재가 빈번한 곳에 구축하는 것을 목적으로 하고 있다. 가스와 불꽃을 감지하는 센서로 화재를 감지하고, 디스플레이와 LED 그리고 소리를 통해 화재발생을 알려준다. 그 후, 스프링클러가 작동하여 초기화재에 대응에 도움을 주고 119에 자동으로 신고가 된다. 일정 수치의 센서에 대한 감지 값을 인식하고 인식한 감지 값에 반응하여 화재 대처를 가능하게 구현하는 시스템을 제안한다. 감지센서를 통한 화재장소에서의 불꽃과 가스를 감지하게 되어 스프링클러가 1차적으로 화재의 번짐을 지연해 주고 은근 소방서에 자동적으로 신고를 하게 되는 자동화 프로그램 이행을 목표로 하고 있다.

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The Rise of Drone Swarms: Military Applications, Countermeasures, and Strategic Implications

  • Hwang Hyun-Ho
    • International Journal of Advanced Culture Technology
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    • v.12 no.2
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    • pp.318-325
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    • 2024
  • The rapid advancement of drone technology has led to the emergence of drone swarms, a game-changing concept in modern warfare. This study explores the military applications, countermeasures, and strategic implications of drone swarms. By examining the current trends in drone swarm development and deployment, this research highlights the potential of this technology to revolutionize the battlefield. The study also investigates the challenges and vulnerabilities associated with drone swarms, emphasizing the need for effective countermeasures. Through an analysis of multi-sensor fusion, directed energy weapons, and artificial intelligence, this research proposes comprehensive strategies to counter the threats posed by drone swarms. Furthermore, the study delves into the ethical and legal issues surrounding the use of autonomous drone swarms, underscoring the necessity for international norms and regulations. The findings of this research contribute to the understanding of the transformative impact of drone swarms on military strategy and national security, while providing valuable insights for policymakers, military strategists, and researchers in the field.

Clothing Management System Using the Smart Hanger Embedded RFID (RFID가 내장된 스마트 옷걸이를 이용한 의류 관리 시스템)

  • Chung, Sung Boo
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.8
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    • pp.185-194
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    • 2014
  • In this paper, we proposed the clothing management system using the smart hanger. Proposed system consists of smart hanger, base module, and server, and the smart hanger consists of MCU, LED, RFID reader, RF chip, ring sensor, and battery. The smart hanger reads the RFID tag attached to the clothes and wirelessly transmitted to the server. The server associated base module communicates with the smart hanger and transmits information to the server. The server manages clothing through the DB, and can display various information through the web page and the smart phone. In order to verify the usefulness of the proposed system, we did experiment with the management system for clothing store and laundry where using a lot of hangers. Performance tests of the smart hanger are applied to check the current consumption and can be predicted the battery life with the proposed low power algorithm. The clothing store management system can be increased sales and convenience of the consumer. The laundry management system can be increased the efficiency of laundry category and convenience of the consumer.