• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.5
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• pp.413-420
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• 2014

Although the transfer forming process has various advantages, it is also inefficient for the use of multiple press machines, especially for small part sizes. In this study, a new forming process was proposed to use multiple tandem dies in a single press machine. A rotary transfer forming device was developed to combine the advantages of the progressive and transfer forming process. In this study, a detailed forming process using this device was analyzed, and the device was designed to perform four series of tandem forming processes in a single press. In order to analyze the feasibility of this forming process, simple forming dies were made. As a result, the position accuracy was 4 arcsec, and the forming speed reached up to 20 strokes per minute. It is thought that this rotary transfer forming device can help to save initial setup costs through the more efficient use of space in a press machine.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.1
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• pp.72-78
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• 2008

Metal stamping is widely used in the mass-production process of the automobile. During the stamping process, air may be trapped between the draw die and the panel and/or between the punch and the panel. Air pocket rapidly not only increases forming load in the final stage, but also deforms the product just formed by compressive air inside the air pocket in knockout process. To prevent these problems air bent holes are drilled in the die to exhaust the trapped air but all processes associated with air bent holes are performed by empirical know-how of workers in the field due to lack of researches. Therefore this study developed an automated design system for predicting the shape and position, and volume of air pocket on the draw die by using the AutoLISP language under AutoCAD circumstance. The system is able to display the shape of air pocket occurred in the draw die and to calculate automatically its volume by strokes. So it makes a stepping stone to calculate theoretical size of an air bent hole and numbers according to it by predicting and analyzing the position and volume of air pocket. Results obtained from the system enable the designers or manufacturers of the stamping die to be more efficient in this field.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.4
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• pp.526-533
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• 2007

In this paper, we study to the pattern of job satisfaction using four theories of transactional analysis-egogram, life positions, strokes, time structuring-for organizational members. The tool of pattern analysis is used fuzzy TAM network which Is especially effective for pattern analysis. The input data of fuzzy TAM network ate values of four theories in transactional analysis, the output data is the classes which is divided by two groups from score of job satisfaction. From the result of this study, the correct rates of training data and checking data are 85-100% and 60%, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.2
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• pp.112-123
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• 1990

This paper presents a vertex-detecting of Hanguel patterns using nested contour shape. Inputed binary character patterns are transformed by distance transformation method and make a new file of transferred data by analysis of charactersitcs. A new vertex-detecting algorithm for recognizing Hanguel patterns using the two data files is proposed. This algorithm is able to reduce the projecting parts of Hanguel pattern, separate the connecting parts between different strokes, set the code number by transformed value of coorked features. It makes the output of results in order to apply the Hanguel recognition.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.10
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• pp.479-484
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• 2002

Recently it is reported that many a malfunction of ELB which is represented by non-operated type ELB for an impulse wave, is caused by lightning impulse and transient ground potential rise due to nearby lightning strokes. In order to examine the cause of malfunction, 5 samples were investigated experimentally in this study. As each ELB has a different leakage current detecting circuit and wiring method, various characteristics were measured. As a result, all of them brought about malfunctions under the lightning impulse voltage less than 7 kV and the surge current less than 3 kA. Also the different aspects were measured with a polarity of injected surge and a position of MOV to protect the inner circuit of ELB. The Position and effects of protecting devices were suggested as a remedy.

• KIEE International Transactions on Power Engineering
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• v.4A no.4
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• pp.236-242
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• 2004

Previous research results indicated that the designed current reduction device could effectively reduce the sheath circulating current and that its RDP protection device could shield it against both fault and lightning strokes. In this paper, cable impedance is analyzed using wavelet analysis and distance relay algorithm following the installation of these devices so that the operation of distance relay can be estimated. The test results confirm that in these devices, the fault inception angle and SVL bonding types have no impact on the change of cable impedance. In other words, the conventional distance relay can be used without a new relay setting. Thus we can finally assert that the designed current reduction device and its protection device are effective and can be safely installed on the cable transmission system without disturbance.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.3
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• pp.91-98
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• 2003

The importance of improving the quality of electric power is being strongly raised, owing to an increasing use of sensitive and small-sized electronic devices and systems. The transient over-voltages on low-voltage power distribution systems are induced by direct or indirect lightning return strokes. These can cause damage and/or malfunction of the utility systems for home automation, office automation, factory automation, medical automation, etc. The behaviors of lightning overvoltages transferred through the transformer to the low-voltage distribution systems using a Marx generator were experimentally investigated. Furthermore, the coupling mechanisms of lightning overvoltages transferred to the low-voltage systems were clearly illustrated through a theoretical simulation using a Pspice program. The overvoltages in low-voltage ac power systems are rarely limited by the application of the surge arrester to the primary side of the distribution transformer. A superior surge protection scheme is to install surge protection devices at the service entrance switchboard and/or at the load devices in TN power systems.

• Journal of Information Processing Systems
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• v.8 no.4
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• pp.653-668
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• 2012

In this study, an improved HMM based recognition model is proposed for online English and Korean handwritten characters. The pattern elements of the handwriting model are sub character strokes and ligatures. To deal with the problem of handwriting style variations, a modified Hierarchical Clustering approach is introduced to partition different writing styles into several classes. For each of the English letters and each primitive grapheme in Korean characters, one HMM that models the temporal and spatial variability of the handwriting is constructed based on each class. Then the HMMs of Korean graphemes are concatenated to form the Korean character models. The recognition of handwritten characters is implemented by a modified level building algorithm, which incorporates the Korean character combination rules within the efficient network search procedure. Due to the limitation of the HMM based method, a post-processing procedure that takes the global and structural features into account is proposed. Experiments showed that the proposed recognition system achieved a high writer independent recognition rate on unconstrained samples of both English and Korean characters. The comparison with other schemes of HMM-based recognition was also performed to evaluate the system.

• Journal of Korean Physical Therapy Science
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• v.18 no.1
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• pp.61-67
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• 2011

Background: The purpose of the present study was to determine correlations between the Berg Balance Scale (BBS), Modified Barthel Index(MBI), Mini-Mental State Examination(MMSE) and Fugl-Meyer motor function Assessment(FMA) in persons with strokes. Methods: We recruited 77 stroke patients from the Seoul Bukbu Geriatric Hospital in Seoul, Korea. Balance was measured by BBS. Activity of Daily Living was assessed using MBI. Cognitive function was examined using MMSE. Motor Recovery was measured using FMA. Data was analyzed using Pearson' correlation. Resurts: There were a statistically significant correlation between BBS and MBI, BBS and MMES, BBS and FMA upper extremity, BBS and FMA lower extremity. There were a statistically significant correlation between MBI and MMSE, MBI and FMA upper extremity, MBI and FMA lower extremity. There were a statistically significant correlated between FMA upper extremity and FMA lower extremity. Conclusions: This study will help rehabilitation program for stroke patients and will be the reference data for selection of therapy and evaluation method.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.3
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• pp.97-124
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• 2012

This paper analyzes qualitatively the stereo 3D content factors causing viewer's discomfort. For this, we perform a subjective test that each subject strokes a specific key whenever he (she) feels discomfort during watching a stereo 3D contents. Also we extract the data for the factors in the 3D contents to obtain their quantitative values and the amounts of the temporal changes. Those two sets of data are used to analyze the contents to find the factors which cause viewer's discomfort. The factors to be considered are the amount and the frequency of the disparity changes, story of the contents, situation or environments of a scene, movement and the position of the camera, color and luminance information as well as disparities themselves. We analyse the various strong and weak factors and their composites to find how much discomfort each factor or composite causes. We also show the situations and their related factors that causes less discomfort than the amount of their disparities.