• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.5
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• pp.55-60
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• 2021

We applied an artificial neural network (ANN) and evaluated surface roughness prediction in lateral milling using an endmill. The selected workpiece was AL6061-T4 to obtain data of surface roughness measurement based on the spindle speed, feed, and depth of cut. The Bayesian optimization algorithm was applied to the number of nodes and the learning rate of each hidden layer to optimize the neural network. Experimental results show that the neural network applied to optimize using the Expected Improvement(EI) algorithm showed the best performance. Additionally, the predicted values do not exactly match during the neural network evaluation; however, the predicted tendency does march. Moreover, it is found that the neural network can be used to predict the surface roughness in the milling of aluminum alloy.

• Korean Journal of Heritage: History & Science
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• v.53 no.3
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• pp.224-243
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• 2020

The rock-cut relief of two Buddhas seated side-by-side in Wonpungri is a large Buddha sculpture in relief on the side of a cliff in Wonpung-ri, Goesan. This Buddha sculpture is from the Buddhist scripture Sutra of the Lotus. <法華經> Two seated Buddhas statues were prevalent in the Balhae Kingdom, but this was not popular in Silla and Goryeo. In the main text, the time that the two seated Buddhas in Wonpung-ri was created is identified as being during the 10th century. King Gwangjong created a Buddha statue for political purposes. The relief of two seated Buddha image carved on a cliff is located on an important traffic route over the Sobaek Mountain Range. After King Gwangjong took the throne, he paid close attention to the reigning powers of Jincheon and Cheongju because the people of Jincheon and Cheongju were engaged in a power struggle against Gwangjong. The huge relief of two seated Buddhas statue shows the authority of King Gwangjong. In particular, the people of Jincheon and Cheongju had to see this Buddha statue when crossing the Sobaek Mountain Range. The image contained in the relief of the two seated Buddhas features many characteristics of the sculpture style of the Balhae Kingdom. After the fall of Balhae, many of the Balhae people settled in Mungyeong. Balhae people from Mungyeong participated in the production of the relief of the two seated Buddhas. Through the relief of the two seated Buddhas, King Gwangjong wanted to show the people of Jincheon and Cheongju that the Balhae people were supporting him. The relief of two seated Buddhas reflects the historical situation of the King Gwangjong era in the late 10^th century and the style of sculpture.

• Physical Therapy Korea
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• v.12 no.4
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• pp.33-40
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• 2005

The purpose of this study was to define more precisely the anatomy of the thumb flexor pulley system and to determine the relative contribution of each of the pulleys to the biomechanics of thumb motion at the metacarpophalangeal (MP) and interphalangeal (IP) joints. For this, 22 hands from 11 cadavers were used and randomly assigned to two groups. In the first group, the first annular (A1) pulley was cut first followed by the variable annular (Av) pulley and then the oblique pulley. In the second group, the oblique pulley was cut first followed by the, pulley and then the Av pulley. In 7 of 22 hands, it was a transverse structure parallel to the, pulley with a gap between the A1 and Av pulleys, referred to here as type I. In 9 hands, the A1 and Av pulleys were connected without any gap (type II). In 6 hands, the space between the A1 and Av pulleys were triangular in shape with fibers of the Av pulley converging toward the radial side (type III). In biomechanical study of both first and second experiments, there was no significant difference in MCP joint flexion between the all intact, A1 section, A1/Av section, A2 intact (A1/Av/oblique section), and no pulley configuration (p>.05). In occurring displacements less than 10 mm, there was no significant difference in IP joint flexion (p>.05). However, there was a significant decrease in IP joint flexion occurred in both 15 mm and 20 mm excursion (p<.05), when the oblique pulley was resected additionally after cutting the A1 and Av pulleys in first experiment, and when the A1 pulley was resected additionally after cutting the oblique pulley. According to the results, the injury of only the oblique pulley does not decrease thumb motion significantly. The oblique pulley injury with both the A1 and Av pulleys laceration decreased thumb motion significantly. The additional laceration of the A2 pulley does not decrease thumb motion.

• Transactions of Materials Processing
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• v.7 no.1
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• pp.81-93
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• 1998

Identification of forming limits of sheet metals is an important task to be done before the sheet metal forming processes. The information of the forming limit is indispensable for design of deformed shapes and related forming processes. This procedure becomes more important than ever as the auto-body becomes complicated and the number of auto-body parts is reduced for lower production cost. To identify the forming limit of sheet metals stretching with a hemispherical punch has gained popularity because of the convenient experimental procedure. The stretching experiment however has localized deformation or the shear band is originated from the non-unifrom deformation in the critical circum-stance instead of the absolute criterion. More accurate information of the forming limit therefore could be obtained by a more appropriate experiment to the real process. In this papaer an experiment program is devised to practivally identify the forming limits of sheet metals for auto-body parts. The experiment program contains not only stretching but deep-drawing Both forming experiments use the same hemispherical punch while they use different specimens. Deep-drawing experiments use speci-mens cut out in circular arc on both sides of circular blank to make it torn during the deep-drawing They also use speciments cut out straight in one side of a circular blank to make it deformed unevenly which causes local deformation during the deep-drawing. The experimental result demonstrates that the forming limit diagrams in the two cases show difference in their effective magnitude. The forming limit curve from deep-drawing is located lower than that from stretching. It is noted from the result that the deep-drawing process causes acceleration of localized deformation in comparison with the stretching process. From the experimental result the maximum value of forming limit could be pre-dicted for safe design.

• Korean Journal of Oriental Medicine
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• v.11 no.2
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• pp.141-154
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• 2005

The following is a taxonomic list of the specific features of external and internal shape and pattern analysis of Paeonia lactiflora PALL. and P. obovata MAX as the standard of herbal medicine. 1. External shape of original plant P. lactiflora has lancelate and elliptical leaves with no hair on both sides. It bears a flower bud at the shoot apex or leaf axil. On the other hand, P. obovata has obovate leaves with hair on the back side. It has a single flower bud at the shoot apex. 2. Physical characteristics of herbal states P. lactiflora has a bright and smooth external surface whose color is light red brown, light gray on its section and it is not easy to cut. On the other hand, P. obovata has a coarse external surface whose color is dark brown, pinkish on its section and it is easy to cut. 3. Physical characteristics of herbal state in currents Paeonia Radix Alba is brown on the external surface, and whitish on its section. On the other hand, Paeonia Radix Rubra is dark brown on the external surface, and yellowish-white on its section. 4. Internal characteristics Internal shape is correspond to that of Paeonia Radix described in literatures. Only P. lactoflora has a concentrated vascular bundle toward centeral cylinder. On the other hand, P. obovata has a scattered vascular bundle at the cortex. 5. Physicochemical pattern by HPLC Both P. lactoflora and P. obovata showed the same pattern. Paeoniforin, a main component, appears upon 13.68 in retention time (Rt) in both. In addition, both contain a large amount of paeoniflorin. Such results will, in the future, be used as basic source for the additional research, such as biological reactions and genetic discrimination.

• Journal of Broadcast Engineering
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• v.9 no.2
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• pp.151-163
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• 2004

In this paper, we propose a content-based video indexing and retrieval system using MPEG-7 standard to retrieve and manage videos efficiently. The proposed system consists of video indexing module for a video DB and video retrieval module to allow various query methods on a web environment. Video indexing module stores metadata such as manually typed in keywords, automatically recognized character names, and MPEG-7 visual descriptors extracted by indexing module into a DB in a sever side. A user can access to retrieval module by a web and retrieve desired videos through various query methods like keywords, faces, example and sketch. For this retrieval system, we propose ATC(Adaptive Twin Comparison) as a cut detection method for efficient video indexing and QBME(Query By Modified Example) as an improved content-based query method for the convenience of users. Experimental results show that the proposed ATC method detects cuts well and the proposed QBME method provides the conveniences better than existing query methods such as QBE(Query By Example) and QBS(Query By Sketch).

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.1
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• pp.73-81
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• 1991

The purpose of this study was to analyze the position of mandibular condyle on the submentovertex radiograph, thereafter to evaluate the usefulness of submentovertex radiograph in diagnosis of temporomandibular joint dysfunction, and to check the best method of tomographic techniques. Submentovertex radiographs which were taken in 75 temporomandibular joint dysfunction patients and 75 normal persons were used as the sample for this study. The obtained results were as follows: The submentovertex radiograph was a improper method in diagnosis of temporomandibular joint dysfunction and discrimination of affected side. The selective tomography was a better method than any other tomographic techniques in diagnosis of temporomandibular joint dysfunction.

• Economic and Environmental Geology
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• v.2 no.3
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• pp.58-67
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• 1969

Songgwang lead zinc mine is located in about 12km to the north-east of Jeonju City. Geology of the mine and its visinity is consisted of Jeonju series belonged to so-called Okcheon system, Seodaesan tuff formation, Silla series, and the quartz porphyry intruded into these formations. Jeonju series comprising 3 formations; that is, of Sadaeri, Sindong, and Girinbong. Jeonju series is generally distributed in southern part of the area, striking NNW, and diping NE $30^{\circ}$, or NW $30^{\circ}$. It is deformed to form synclinorium and anticlinorium plunging to the north with low angle. In the northern part of the area, Jeonju series was cut by Sinpeongri-fault of NEE direction near Sinpeongri. In the north side of the fault, it is overturned and shows NEE or NWW strikes and NW $60^{\circ}$ dips. At the west of Songgwangri, it is cut by 3 thrusts; the two are almost parallel each other, and the third oneis manifested by the fact that the lower black shale zone thrusted over the upper limestone. Songgwangri thrust, so named, is a post-mineral fault and its plane represents a premineral slip plane. Enrichment of are took place along the bedding plane or fissure parallel to it, as seen in adit No. 1 or No. 2 along the floor of the thrust, and along the sheared zone or the brecciated zone oblique to the plane near the thrust in crystalline limestone of Sindong formation as observed in the underground levels of inclined slope. Ore minerals are chiefly zincblende, galena, pyrrhotite, arsenopyrite, acompanied pyrite and chalcopyrite, and contain Au and Ag. In earlier stage of mineralization, the limestone was recrystalized, and sulphide minerals were enriched in the· permiable zone said above by pyrometasomatism, and in later stage the limestone was affected chloritization and sericitization. However hydrothermal replacement was weak, so that enrichment did not took place. It seems that minerallizing materials came up through the premineral slip plane and injected, and replaced the limestone in permiable zone said above with sulphide are minerals. Then Songgwangri thrust took place and, the lower black shale zone thrusted upon crystalline limestone.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.3
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• pp.51-58
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• 2008

This paper is a study of a prevention of power folding controller's thermal degradation. Power folding technology has been applied for many fields such as side rear vision mirror of vehicles, windshield wiper, antenna, power window. These controllers have been comprised with traditional DC moors, Switching electronic devices, and relays. But this methods have a limitation to overcome such problems of product reliability, endurance, noise margins. Therefore on this paper, to detect the movement of motor, sensing motor brush noise on a load sensing part has been used and controlling a precise RC timing control minimizes the thermal deterioration of motor. And using MOS FETs as a electronic switching device increases life-time and liability of control circuit. After testing such circuit and control method, repetition of operating time, cut-off time, wide operation voltage, power noise margin ware increased over eleven-fold.

• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.3
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• pp.251-260
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• 2003

Tunnel blasting has been performed with V-cut to investigate the characteristics. Blasting vibrations were measured at two directions, the proceed direction and side direction. Propagation characteristics were determined by regression analysis; square root scaled distance and cube root scaled distance with maximum charge per delay of the blast. Testing result, The cross point was 62m in the allowable vibration velocity of 3mm/sec and 46m in 5mm/sec. Also, vibration level with measuring point was highest and decayed fastest, adapting to cube root scaled distance, for the proceed direction on ground.