• Kyungpook Mathematical Journal
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• v.48 no.2
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• pp.195-206
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• 2008

The purpose of this note is to compare the rings of continuous functions, integer-valued or real-valued, in pointfree topology with those in classical topology. To this end, it first characterizes the Boolean frames (= complete Boolean algebras) whose function rings are isomorphic to a classical one and then employs this to exhibit a large class of frames for which the functions rings are not of this kind. An interesting feature of the considerations involved here is the use made of nonmeasurable cardinals. In addition, the integer-valued function rings for Boolean frames are described in terms of internal lattice-ordered ring properties.

• Journal of Korean Society of Forest Science
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• v.111 no.2
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• pp.242-250
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• 2022

Here we aimed to date the year and season of the resin collection from Korean red pines at Worak mountain and investigate the natural healing ability of the wounds using the tree-ring analysis technique. We determined the dating of the resin collection based on the synchronization between the ring-width time series from the wound surface of the experimental trees and the local master chronology, which is the mean time series from the sound surface on the opposite side of the wounds. For the dating of resin collection, we selected thirteen Korean red pines with resin wounds. For the investigation on the annual healing ability of the wounds, we sampled three dead trees out of 13 trees as disks. Through the comparison of the individual ring-width time series from the wounds with the local master chronology, it was verified that the resin collection was undertaken between the spring of 1962 and the autumn of 1975. The mean healing length of the wounds was 15.8 cm over the preceding 42 years, making their annual mean healing 0.38 cm. Through our study we successfully verified the healing ability of the wounded Korean red pines for the resin collection as well as the undocumented resin collection history.

• The Journal of Korean Association of Computer Education
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• v.5 no.3
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• pp.19-25
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• 2002

Bluetooth, in radio network environment, is a small local radio communication that is available with low expense and little power use. It is specified for the wireless connect in a small area between Network Excess Point, portable devices such as mobile phones. PDAs and portable PCs, and other per peripheral equipment. Bluetooth is consisted of a master and a piconet having seven slaves in a maximum and finally has a scatternet gathering lot of piconet. The thesis tries to design the most effective structure of a scatternet by the number of nodes and the type of scatternet such as linear and ring for its mechanism. then the performance evaluation is realized through the Bluehoc simulator based on the NS. Finally the most appropriate radio network environment is made by the comparison and analysis of the characteristics of liner and ring scatternets.

• Korean Journal of Optics and Photonics
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• v.5 no.1
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• pp.84-89
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• 1994

A tunable pulsed dye laser was operated in a single longitudinal mode by injection locking with a cw ring dye laser. A doubled Nd:YAG laser was used as the pumping source. Phase sensitive detection technique was applied to maintain the required match between the master laser frequency and the slave resonator cavity length. The fluctuation of the center frequency of the pulsed laser was < 10 MHz, and the pulse duration (FWHM) was 6 ns. The linewidth measured by scanning confocal interferometer was 130 MHz. When pumped by 50 mJ of the doubled Nd:YAG laser, the output energy of the pulsed dye laser was 2 mJ and the peak power was 330 kW. 30 kW.

• Korean Journal of Heritage: History & Science
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• v.47 no.1
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• pp.152-163
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• 2014

In this study, Gwanghanru Pavilion (Namwon-si, Cheonbuk Province) was dated by tree rings of pines (Pinus densiflora Sieb. et Zucc., 'sonamu' in Korean). The present Gwanghanru Pavilion is composed of three parts: main, wing and entrance parts. The main part is known to have been built in 1626 and the entrance hall in 1879, but the date of construction of the wing part is still unknown. We dated a total of 55 wood samples which were replaced during the repair process in 2001~2002. Tree-ring dates indicated that both main and wing parts were built in 1626. Tree rings also revealed that the entrance hall was constructed in 1880~1881, and both main and wing parts were heavily repaired together while appending the entrance hall. In conclusion, dendrochronology, i.e., tree-ring dating, was a useful and accurate method to identify the critical dates-such as the dates of original construction, reconstruction, repairs and extensions-for the history of Korean traditional buildings.

• Electrical & Electronic Materials
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• v.8 no.4
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• pp.504-508
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• 1995

The purpose of this research is to study on characteristics of corona ignitor which was designed for ignition of plasma, used at hard coating, surface treatment and thin film preparation, at high pressure. Corona ignitor composed of hollow type inner electrode and ring type external electrode. Though corona voltage increased with increasing distance between electrodes, corona discharge can be controlled stably. The gas flow in hollow type inner electrode and the construction between electrodes affect a length of corona flame and corona phenomenon. It is possible to ignite the . plasma, usually generated at low pressure(10 Torr), at high pressure(100 Torr) by corona ignitor.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.193-200
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• 2003

In this study a general Galerkin FE formulation of the incompressible Reynolds equation is derived for lubrication analyses of noncontacting mechanical face seals. Then, the formulation is applied to analyze the flexibly mounted stator-type reactor coolant pump seals of local nuclear power plants, which have deep straight grooves or plane coning on their primary seal ring faces. Their various lubrication performances have been predicted. Results show that the analyzed deep straight groove seal should have a net coning of less than $0.6\;{\mu}m$ to satisfy the leakage limit. And for the same amount of equilibrium opening force the plane coning seal requires to have a 3 times higher dimensionless coning than the deep straight groove seal.

• Journal of Magnetics
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• v.18 no.2
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• pp.90-94
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• 2013

We designed a model composed of a ring type magnet, a yoke, and a sensing coil embedded in a projectile for simulating the muzzle velocity. The muzzle velocity was obtained from the master curve for the induced voltage at sensing coil and the velocity as the projectile pass through the magnetic field. The induced voltage and the projectile's velocity are fitted by the $2^{nd}$ order polynomial. The skin effect difference between projectiles which consist of aluminum-aluminum and aluminum-steel was small. The projectile will surely be burst at the pre-determined target area using the flight time and the projectile muzzle velocity calculated from the voltage induced at the sensing coil on the projectile.

• IEMEK Journal of Embedded Systems and Applications
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• v.16 no.6
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• pp.247-251
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• 2021

We propose a protocol for Ethernet-based industrial real-time communication networks. In the protocol, the master periodically transmits control frames to all slaves, and the ring-type network topology is selected to achieve high-speed transmission speed. The proposed protocol is implemented in the form of both firmware and Linux kernel modules. To improve the transmission speed, the MAC address table is disabled in the firmware implementation, and the NAPI function of the Ethernet driver is removed in the Linux kernel module implementation. A network experiment environment is built with four ARM processor-based embedded systems and network operation experiments are performed for various frame sizes. From the experimental results, it is verified that the proposed protocol normally operates, and the firmware implementation shows better transmission speed than the Linux kernel module implementation.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.3
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• pp.56-62
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• 1996

This paper presented a new measuring system to improve circular motion accuracy by using two-dimensonal probe and master ring for NC machine tools. This measuring system reduced the circular motion error conspicuously by eliminating the influence of the acceleration/deceleration range and compensating the friction force whose influences were significant while measuring the motion. Experimental results show that this system had enough accuracy to measure a circular motion for NC machine tools, compared with the circular test method and the r .theta. method.