• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.1
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• pp.52-58
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• 2014

This study consists of two parts. The first discusses the development of a single production forming machine which was reported in earlier papers. The second outlines the development of a multi-production forming machine, which consists primarily of a film feeding unit, an unwinding unit, and a heating block unit. The heating block unit of the multi-production forming machine has 30 members per die. An analysis of the stress deformation and temperature deviation of this machine is carried out using ANSYS Workbench and CFX-11 under the design conditions. According to this analysis, the maximum deflection in the Z-direction is $0.05104{\mu}m$ and the maximum temperature deviation is $0.7^{\circ}C$ when the temperature of the heating block unit is $175^{\circ}C$. It was also found that these values are structurally safe. The advantage of the developed multi-production forming machine is demonstrated to be in its offering of a proper voice test.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1172-1179
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• 2010

In this paper, we analyze and design requirements of Network Function block and System Function block of MiTS network protocol based on Light-Weight Ethernet, also implement and test the protocol and library files. Light-Weight Ethernet Protocol consists of Network Function block and System Function block. NF receives and sends datagram based on UDP multi-casting communication. SF processes messages after distinguished Sentence and Binary Image Data.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.6
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• pp.626-631
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• 2012

In this study, fatigue life of the motor block bracket units for KTX-Sancheon trains was assessed. Design evaluation for railway structures was performed based on the UIC 566 regulation, and test and evaluation of fatigue life in welded parts was performed in accordance with standard ERRI B 12/RP17 and ERRI B 12/RP60. The actual vehicle dynamic stress testing was executed in KTX-Sancheon service line with the service operating speed. The dynamic stress was measured with commercial data acquisition system (MGC plus). The cumulative damage was evaluated by applying standard BS 7608 - Class F and cycle counting was used rain-flow counting method. As a result, the motor block bracket units for KTX-Sancheon trains was designed to fit the regulation and the safety of fatigue life for 30 years, assuming that KTX-Sancheon trains travels 600,000km annually, were confirmed under current operating conditions.

• Journal of the Korean Data and Information Science Society
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• v.24 no.1
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• pp.95-103
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• 2013

Nonparametric procedure in randomized block design (RBD) was proposed by Friedman (1937) for general alternatives. Also Page (1963) suggested the test for ordered alternatives in RBD. In this paper, we proposed the new nonparametric method in randomized block design using aligned method suggested by Hodges and Lehmann (1962) and the joint placement described in Chung and Kim (2007). Also, Monte Carlo simulation study was adapted to compare the power of the proposed procedure with those of previous procedure.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.1
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• pp.41-46
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• 2018

Background: The purpose of this prospective randomized single-blind clinical trial was to evaluate the effect of tilting the head on the anesthetic efficacy of inferior alveolar nerve block (IANB) in patients with symptomatic irreversible pulpitis. Methods: Ninety-two patients were divided into two groups: the first group received IANB and the head was tilted in the direction of the block for 15 min, whereas the second group received IANB and the head was tilted to the opposite side. Access cavity preparation was initiated after 15 min. Success was defined as no pain or faint/weak/mild pain during endodontic access preparation and instrumentation. The anesthetic success rates were analyzed by Pearson chi-square test at 5% significance levels. Results: The same side position and opposite side position yielded 41% and 30% anesthetic success rates, respectively; there was no significant difference between the two sides. Conclusions: Relative head position has no effect on the anesthetic success rate of IANB.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.3
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• pp.694-701
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• 2004

In this paper, we proposed a feature-based tracking system that traces moving objects with a pan-tilt camera after separating the global motion of an active camera and the local motion of moving objects. The tracking system traces only the local motion of the comer features in the foreground objects by finding the block motions between two consecutive frames using a block-based motion estimation and eliminating the global motion from the block motions. For the robust estimation of the camera motion using only the background motion, we suggest a dominant motion extraction to classify the background motions from the block motions. We also propose an efficient clustering algorithm based on the attributes of motion trajectories of corner features to remove the motions of noise objects from the separated local motion. The proposed tracking system has demonstrated good performance for several test video sequences.

• Bulletin of the Society of Naval Architects of Korea
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• v.7 no.2
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• pp.27-40
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• 1970

The distribution of stress and strain in elastic stages is investigated by the experiments of two dimensional photoelastic coating and Moire fringe method. Center block type and cover plate type of fillet welds are used as specimens in the test. The results are as follows. 1) Center block type gets less uniform stress distribution than cover plate type. And its stress concentration factor, especially at root, is larger than that at toe. 2) When main plate and cover plate closely contact and it cause friction, stress concentration decreases more than that in case of slit. That is because stress can be transmitted on the contact surface. 3) When slit is made, the outside of fillet gets more stress than the inside of it. 4) While the plastic strain distribution of center block type reaches the maximum at root and differs very slightly from that under lower loading, the plastic strain distribution of cover plate type is inclined to get the maximum at the outside of fillet rather than at root. 5) When the plastic strain value of cover plate type is compared with that of center block type at toe and root, the relations between the former and the latter shows root<toe and root>toe. 6) Because stress distribution becomes changed according to loading, fracture angle cannot be estimated by the peaks of elastic stress distribution. 7) The strain distribution just before fracture can be found by Moire fringe method.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.6
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• pp.377-384
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• 2022

In the design of composite aircraft structures, it is very important to set material allowables and design values, which take into account certification. And when determining the material allowable and design value of composite structures, the static strength, damage tolerance requirements, and environmental effects should be considered. The building block approach has been applied to the civil and military aviation industry for a long time and provides the principal certification methodology. This current certification methodology is based on extensive testing including coupon, element, sub-component, and full scale test. In this paper, some examples of composite allowable tests have been presented and the fundamental background and application methods of the building block approach have been presented.

• The Transactions of the Korea Information Processing Society
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• v.4 no.4
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• pp.1141-1151
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• 1997

In this paper the Maximum Block Method is suggested for the Feature Extraction of stokes of off-line Chinese characters.The Maximum Block Method is a technique which enlarges the block from the first found pixel that wxtracts the skeleton and features of the input characters.The maximum Block mthod is an adequate technique for the correct extraction of the features since the exsting thining methods have shortcomings of making the feature extraction difficult from the distoritions generated from the effiects of the parial noises,inflection points and blemishes. The printed outputs and chinese books of the middle and high school students,and other materials are used for the test.It was found that the Maxthod is also an effective technique for the extraction of skeleton line and features,which is the preoprocessing of the pattern recognition,for the Korean chracters and English as well as chinese chracters.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.2
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• pp.459-470
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• 2014

During ship design, welding-induced distortions are roughly estimated as a function of the size of the component as well as the welding process and residual stresses are assumed to be locally in the range of the yield stress. Existing welding simulation methods are very complex and time-consuming and therefore not applicable to large structures like ships. Simplified methods for the estimation of welding effects were and still are subject of several research projects, but mostly concerning smaller structures. The main goal of this paper is the application of a multi-layer welding simulation to the block joint of a ship structure. When welding block joints, high constraints occur due to the ship structure which are assumed to result in accordingly high residual stresses. Constraints measured during construction were realized in a test plant for small-scale welding specimens in order to investigate their and other effects on the residual stresses. Associated welding simulations were successfully performed with fine-mesh finite element models. Further analyses showed that a courser mesh was also able to reproduce the welding-induced reaction forces and hence the residual stresses after some calibration. Based on the coarse modeling it was possible to perform the welding simulation at a block joint in order to investigate the influence of the resulting residual stresses on the behavior of the real structure, showing quite interesting stress distributions. Finally it is discussed whether smaller and idealized models of definite areas of the block joint can be used to achieve the same results offering possibilities to consider residual stresses in the design process.