• Journal of Sensor Science and Technology
• /
• v.23 no.1
• /
• pp.24-28
• /
• 2014

A lock-in amplifier was proposed for capacitive sensor applications. This amplifier was based on a general-purpose microcontroller and had only a charge amplifier as analog circuits. All the other functions of lock-in amplifier except for the charge amplifier were implemented with firmware and the internal resources of the microcontroller. A rectangular signal, generated by the microcontroller, was used in a sensor-driving signal instead of a conventional sinusoidal signal. This makes it possible that the phase comparison circuit in the lockin amplifier is made with analog-to-digital converter, a timer and an interrupt controller. Using the oversampling method and the rectangular driving signal, we can make it easy to implement the peak detection function with software and sample the peak-to-peak signal at charge amplifier output. A charge amplifier was proposed to cancel out the base capacitance existing in capacitive sensors structurally. The experimental results show that the lock-in amplifier operating in the supply voltage of 3.0 V cancels out the base capacitance and has good linearity.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.33 no.1
• /
• pp.40-45
• /
• 2013

The purpose of this study was to detect the pin hole defect of dental composite restoration using lock-in thermography method. Amplitude and phase images of the composite resin specimens were analyzed according to the lock-in frequency and the diameter of defect area. Through the amplitude image analysis, at lock-in frequency of 0.05 Hz, defect diameters 2-5 mm exhibited the highest amplitude contrast value between defective area and sound area. The lock-in frequency range of 0.3-0.5 Hz provided good phase angle contrast for the defect area. At lock-in frequency range of 0.5 Hz, defect diameter of 5 mm exhibited the highest phase contrast value. It is concluded that the infrared lock-in thermography method verified the effectiveness for detecting the pin hole defect of dental composite restoration.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.30 no.1
• /
• pp.37-41
• /
• 2017

In this paper, the fault current limiting characteristics of the flux-lock type SFCL (superconducting fault current limiter) using magnetic application circuit were analyzed. The flux-lock type SFCL has the structure to install the magnetic application circuit, which can increase the resistance of HTSC ($high-T_C$ superconducting element comprising) the SFCL. To analyze the fault current limiting effect of the flux-lock type SFCL through the magnetic flux application circuit, the flux-lock type SFCL either with the magnetic flux circuit or without the magnetic flux circuit was constructed and the fault current limiting characteristics of the SFCL were compared each other through the short-circuit tests.

• Journal of the Semiconductor & Display Technology
• /
• v.16 no.4
• /
• pp.63-67
• /
• 2017

In this study, We developed a simple and low cost capacitive pressure mapping sensor and microcontroller-base lock-in amplifier array. We developed capacitive type pressure mapping sensor by forming the electrode and adhesives on plastic films using only the printing process, and the finishing the process by bonding the two films. Lock-in amplifier array was based on a general purpose microcontroller and had only a charge amplifier as analog circuits. In this study, a $10{\times}10$ capacitive type pressure mapping sensor and lock-in amplifier array was fabricated and its characteristics were analyzed.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.6 no.1
• /
• pp.47-80
• /
• 1984

The aim of this paper is to study the classification and arrangement system, the original texts, and the bibliographic deseription of Dae-Jang-Mock-Lock. The results of this study can be summarized as followings; 1. The first carving of Dae-Jang-Mock-Lock was assumed to be completed at latest by 1087 (King Sun-Jong 4, Koryo) when the first carving of Dae-Jang-Kyong, the complete collection of Buddhist Sutra, mas finished. Henee, Dae-Jang-Mock-Lack is safely said to be the oldest catalog in Korea. 2. The major function of Dae-Jang-Mock-Lock mas to facilitate the job of printing, managing, or arranging the Sutra tablets, rather than to serve as its references. 3. Dae-Jang-Mock-Lock mas classified in accordance with the classification sys tern of Gae-Woon-Suck-Kyo-Lock, a chinese Buddhist catalog. This system classified the complete collection of Buddhist Sutra into the three categories of "Mah$\={a}$y$\={a}$na Tripitaka", "Hinayan$\={a}$ Tripitaha", and "collected Biographies of Samgha", at the first gradation. And then the Mah$\={a}$yan$\={a}$ Tripitaka mas divided into the three categories of "Mah$\={a}$y$\={a}$na Sutra", "Mah$\={a}$y$\={a}$na Uparaksa", and "Mah$\={a}$y$\={a}$na Upadesa", at the second gradation. In the same manner the "Hinayan$\={a}$ Tripitaka was divided into "Hinayan$\={a}$ Sutra", "Hinayan$\={a}$ Uparaksa", and "Hinayan$\={a}$ Upadesa". The "Collected Biographies of Samgha" was divided into Brahman Samgha and Chinese Samgha. For this reason we Can name this main classification system as a Tripitaka Classification. 4. The first carving tablets of the Buddhist Sutra from Choen Shelf (天函) to Young Shelf (英函) were the same Sutra that were included in Gae-Woen-Suck-Kyo-Lock (開元釋敎錄), except those 4 omitted sutras of 22 volumes. But the other 7 sutras of 24 volumes were included as an extra addition in "Dae-Jang-Mock-Lock." 5. The 40 shelves and 376 volumes of Buddhist Sutra from the Doo Shelf (杜函) to the Kyong Shelf (輕函) in Dae-Jang-Mock-Lock were copied from the texts of Guran Edition (契丹本) 6. The 36 shelves of Buddhist Sutras from the Bun shelf (磻函) to the Mil shelf (密函) in Dae-Jang-Mock-Lock were the same as those included in Sock-Jung-Woen-Suck-Kyo-Lock (續貞元釋敎錄), except the 3 omitted sutras.

• Korean Journal of Optics and Photonics
• /
• v.34 no.2
• /
• pp.76-83
• /
• 2023

In this paper, the results of analyzing the frequency lock-in breaking characteristics of a ring laser gyroscope with random dithering through numerical experiments are presented. By observing the variant features in the frequency lock-in characteristics according to the dithering amplitude noise, it was possible to analyze the minimum noise condition that causes the frequency lock-in to be broken. It was confirmed that the result is closely related to the relative difference between the dynamic frequency lock-in corresponding to the average dithering amplitude and the frequency determined by the Sagnac effect corresponding to an input rotational angular velocity.

• Transactions on Electrical and Electronic Materials
• /
• v.7 no.2
• /
• pp.87-89
• /
• 2006

We investigated the current limiting characteristics of flux-lock type superconducting fault current limiter(SFCL) according to inductance variation of coil 2. The flux-lock type SFCL consists of two coils. The primary coil is wound in parallel to the secondary coil through an iron core, and the secondary coil is connected to the superconducting element in series. The operation of the flux-lock type SFCL can be divided into the subtractive and the additive polarity winding operations according to the winding directions between the coil 1 and coil 2. The current limiting characteristics in two winding directions were dependent of on the ratio of the number of turns of coil I and coil 2. The fault current increased when the number of turns of coil 2 increased in the subtractive polarity winding. On the contrary, the fault current decreased under the same conditions in case of the additive polarity winding.

• Journal of Korea Game Society
• /
• v.20 no.5
• /
• pp.53-64
• /
• 2020

Supporting NNS method in KD-Tree algorithm is essential in multidimensional data applications. In this paper, we propose HD-Tree, a high-performance Lock-Free KD-Tree that supports NNS in situations where reads and writes occurs concurrently. HD-Tree reduced the number of synchronization nodes used in NNS and requires less atomic operations during Lock-Free method execution. Comparing with existing algorithms, in a multi-core system with 8 core 16 thread, HD-Tree's performance has improved up to 95% on NNS and 15% on modifying in oversubscription situation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.8
• /
• pp.747-753
• /
• 2005

We Investigated the current limiting characteristics of the flux-lock type superconducting fault current limiter(SFCL) by fault angles. The flux-lock type SFCL consists of the primary and the secondary copper coils wound in parallel through the iron core and YBCO thin film. In this paper, the current limiting characteristics of the flux-lock type SFCL by fault angles in case of the subtractive and the additive polarity windings were compared and analyzed. The flux-lock type SFCL limited fault current more quickly as the fault angles increased. On the other hand, the initial power burden of the superconducting element during the fault increased as the fault angles increased. In addition, we found that the resistance of the flux-lock type SFCL in case of the subtractive polarity winding was more increased than that of the additive polarity winding. The peak current of the fault current in case of the subtractive polarity winding was larger than that of the additive polarity winding.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.9
• /
• pp.856-862
• /
• 2005

A flux-lock type SFCL consists of two coils, which are wound in parallel each other through an iron core, and a HTSC thin film connected in series with coil 2. If the current of the HTSC thin film exceeds its critical current by the fault accident, the resistance generated of the HTSC thin film, and thereby the fault current can be limited by the impedance of the flux-lock type SFCL. The amplitude of fault current can be set by the impedance of the flux-lock type SFCL. In this paper, we investigated the variance of the limiting current due to the ratio of inductances between coil 1 and coil 2 in the flux-lock type SFCL through the computer simulations and short circuit tests. In addition, both the simulation results and experimental ones were compared each other. From the comparison of both the results, the simulation results agreed well with the experimental ones.