• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.551-564
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• 2016

High-speed flight vehicles (HSFVs) such as space launch vehicles and missiles undergo severe dynamic loads which are generated during the launch and in in-flight environments. A typical vehicle is composed of thin plate skin structures with high-performance electronic units sensitive to such vibratory loads. Such lightweight structures are then exposed to external dynamic loads which consist of random vibration, shock, and acoustic loads created under the operating environment. Three types of dynamic loads (acoustic loads, rocket motor self-induced excitation loads and aerodynamic fluctuating pressure loads) are considered as major components in this study. The estimation results are compared to the design specification (MIL-STD-810) to check the appropriateness. The objective of this paper is to study an estimation methodology which helps to establish design specification for the dynamic loads acting on both vehicle and electronic units at arbitrary locations inside the vehicle.

• Journal of Sensor Science and Technology
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• v.27 no.5
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• pp.340-344
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• 2018

Electrodes are an important part of electrocardiography (ECG); disposable electrodes have been extensively used. However, personal ECG monitoring devices for Internet of Things applications require reusable electrodes. As there have been no systematic studies on the characteristics of reusable electrodes to date, we conducted this study to assess the performance and feasibility of electrodes with different materials. We built reusable electrodes using twelve different metallic materials, including commonly used copper, silver, zinc, plating materials, chemically inert titanium, stainless steel, and aluminum. Each electrode was fabricated to a size of $5{\times}10mm$. Their characteristics such as offset, baseline drift, stabilization time, and chemical inertness were compared. A personal ECG monitoring system was used to test the manufactured electrodes. The performances of the Ag, Cu, and Zn electrodes were better than the performances of other electrodes. However, these materials may not be used owing to the chemical changes that occur when the electrodes are in contact with the skin, such as discoloration and corrosion, which deteriorate their electrical characteristics. Titanium, stainless steel, and aluminum are chemically stable. The titanium electrode showed the best performance among the three, and it is our recommendation as a material for manufacturing reusable electrodes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.1
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• pp.52-58
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• 2004

Magneto-Impedance(MI) sensor is a highly sensitive sensor, which was able to detect a weak geomagnetic field. It also has a merit to be able to build in the low power system. In this study, their magnetic permeability and anisotropy field(H$\sub$k/) as a function of some different thickness of sputtered amorphous CoZrNb films with zero-magnetostriction and soft magnetic property are investigated. In order to make a uniaxial anisotropy, film was subjected to the post annealing in a static magnetic field with 1KOe intensity at 250, 300, and 320$^{\circ}C$ respectively for 2 hours. Magnetic properties of films are measured by using a M-H loop tracer. Magnetic permeability of a film is measured over the frequency range from 1 ㎒ to 750㎒. By thickening a CoZrNb film relatively, magnetic permeability and impedance are examine to design the. MI sensor which drives at 50㎒, and thereof fabricated the MI sensor which drives at the 50㎒.

• Progress in Medical Physics
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• v.30 no.4
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• pp.150-154
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• 2019

The objective of this study is to monitor the radiation doses delivered to a cardiac implantable electronic device (CIED) by comparing the absorbed doses calculated by a commercial treatment planning system (TPS) to those measured by an in vivo dosimeter. Accurate monitoring of the radiation absorbed by a CIED during radiotherapy is necessary to prevent damage to the device. We conducted this study on three patients, who had the CIED inserted and were to be treated with radiotherapy. Treatment plans were generated using the Eclipse system, with a progressive resolution photon optimizer algorithm and the Acuros XB dose calculation algorithm. Measurements were performed on the patients using optically stimulated luminescence detectors placed on the skin, near the CIED. The results showed that the calculated doses from the TPS were up to 5 times lower than the measured doses. Therefore, it is recommended that in vivo dosimetry be conducted during radiotherapy for CIED patients to prevent damage to the CIED.

• Transactions on Electrical and Electronic Materials
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• v.11 no.5
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• pp.226-229
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• 2010

Many methods exist that promote wound healing, including light therapy, which consists of light beams that assist the human body in treating and sterilizing wounds, as well as regenerating cells. Irradiation with specific wavelengths of either laser or LED light has been shown to induce beneficial proliferation of fibroblasts that, depending on the size of the wound, can be effective in promoting wound healing. The experiments in this study utilized 8 week old 250~300 g Male Sprague Dawley Rats (ILAR Code: NTacSam:SD) and included a non-irradiation group and a 525 nm green LED irradiation group (n of each group = 7). In experiments animals were allowed to rest for 24 hours after wounds had been excised, which was followed by non- irradiation or 525 nm green LED irradiation therapy one hour per day for 9 days. Immunohistochemical staining was conducted for cytokeratin in order to precisely measure the defect size. In addition, Masson's trichrome staining was utilized in order to compare levels of collagen between the 525 nm green LED irradiation group and the non-irradiation group. Animals exposed to 525 nm green LED irradiation (p<0.05) healed at a faster rate and had increased collagenosis compared with the non-irradiated control group. Thus, treatment with 525 nm green LED irradiation had a beneficial effect on wound healing and should be considered as a possible alternative to low power laser treatment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.776-781
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• 2008

In this study, ubiquitous health care system attaching in chair to monitor ECG for health care was developed at the unconsciousness state. The system conveniently and simple measured ECG at non-consciousness. We measured the contact impedance to skin-electrode of metal mesh electrodes of the system. Contact impedance enable the electrode to use for ECG measurement. The results are that the impedance of the metal mesh electrodes according to sizes is low when the size is 4$cm^2$. As the result, when the size of the metal mesh electrode is 4$cm^2$, the electrode is fit for ECG measurement. We can acquired by positing the arm on the metal mesh electrode. The ECG signal was detected using a high-input-impedance bio-amplifier, and then passed filter circuitry. The measured signal transmitted to a PC through the bluetooth wireless communication and monitored. Data of the non-constrained ECG system attaching in chair is noise-data when comparing metal mesh electrode with the Ag/Agcl electrode but the data is significant to monitor ECG for check the body state.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.132-135
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• 2002

MI(Magneto-Impedance) sensor which is made by thin films has significantly high detecting sensitivity in weak magnetic field. It also has a merit to be able to build in the low power system. Its structure is simple, which makes it easier to prepare a miniature. In this study, its magnetic permeability and anisotropy field($H_{k}$) as a function of a thickness of sputtered amorphous CoZrNb films with zero-magnetostriction and soft magnetic property are investigated. In order to make a uniaxial anisotropy, film was subjected to the post annealing in a static magnetic field with 1KOe intensity at 250, 300, and $320^{\circ}C$ respectively for 2 hours. Magnetic properties of film are measured by using a MH loop tracer. Its magnetic permeability of a film is measured over the frequency range 1 MHz to 750MHz. And, it was examined on the permeability and impedance to design the MI sensor which acts at 50MHz by thickening a CoZrNb film relatively, and fabricated the MI sensor which acts at the 50MHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.447-450
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• 2013

This paper proposes the way to prevent drowsy driving by recognizing drivers eyes and yawn using a front camera. The method uses the Viola-Jones algorithm to detect eyes area and mouth area from detection face region. In the eyes area, it uses the Hough transform to recognize eye circle in order to distinguish drowsy driving. In the mouth area, it determines whether for the driver to yawn through a sub-window testing by applying a HSV-filter and detecting skin color of the tongue. The test result shows that the recognition rate of yawn reaches up to 90%. It is expected that the method introduced in this paper might contribute to reduce the number of drowsy driving accidents.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.897-902
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• 2018

The purpose of this study is to develop a bioinformatic diagnostic system that diagnoses the patient 's health condition by using the output waveform generated by applying the impulse voltage of 13Hz to 7 body parts based on DFM (Diagnose Fure Funktionelle Medizine) theory. It is expected that the data acquired by the diagnostic system will be served as a device for diagnosing the status of the body organ as well as the mesenchymal tissue through inductive reasoning based on artificial intelligence. In this paper, we will limit the system to acquire and manage bio-signals.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.4
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• pp.733-738
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• 2020

In the recent years, the development of coastal zone has been advancing, and the chance of leisure activity has increased near the sea. However, the destruction of ozone layer has resulted in an increase in the amount of ultraviolet radiation reaching the earth surface. The human body is harmfully influenced as skin cancer and eye damage by ultraviolet radiation. Especially, the effect of ultraviolet radiation on beach is higher than that inland area due to the reflection from the sand. This study is expected to use basic data on the method of measuring ultraviolet reflections on east coast beaches using remote sensing.