• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.217-218
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• 2006

This paper presents an investigation on the characteristics for new micro tool dynamometer by using the ultrahigh-speed air turbine spindle. Recently, the ultrahigh-speed micro flat endmilling has been investigated actively due to request of accuracy improvement and productivity of die and mould manufacturing. To perform efficient ultrahigh-speed micro flat endmilling, evaluation of ultrahigh-speed machinability must be studied preferentially and it can be identified by investigation of cutting force. The cutting forces in ultrahigh-speed micro flat endmilling can be measured by micro tool dynamometer. But general dynamometer has low natural frequency and so is improper for measuring very high frequency cutting forces in ultrahigh-speed micro flat endmilling. In this study, the micro tool dynamometer which has very high natural frequency is newly designed.

• International Journal of Knowledge Content Development & Technology
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• v.11 no.3
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• pp.63-79
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• 2021

The KJC and KCI services operated by the National Research Foundation of Korea (NRF) need to refer to the global citation index database to set the service direction that researchers want and develop new functions. Therefore, in this study, the usability of Korea's KJC and KCI web databases was evaluated. In addition, FGI verification was performed for a group of experts on KJC and KCI improvement measures derived by academic information experts. The evaluation committee consisted of the researcher group, the society related group, the publisher (academic information distribution organization) group, and the policy-making organization group. A total of 16 experts performed usability evaluation and service improvement proposals for KJC and KCI services. As a result of usability evaluation of KJC and KCI web database using SUS measurement tool, KJC service was evaluated as 73.44, and KCI service was evaluated as good as 64.38. KJC improvement proposals were evaluated positively with 4 points or more for all improvement items, and KCI improvement proposals were positively evaluated with 3.5 points or more for all improvement items. Overall, KJC and KCI error improvements were evaluated with a score of 4 or more, showing strong affirmations. In the future, it is hoped that the improvement proposals and improvements proposed in this study will be applied to the development of KJC and KCI services, so that more quality services will be used by domestic researchers.

• Journal of the Korean Professional Engineers Association
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• v.33 no.2
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• pp.62-67
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• 2000

The trouble rank of business management of the small-medium manufacturing enterprises in Korea is constituted by that average 28.6% of production management in the worst trouble of business management from 1982 to 1999. The status of production management approaching problem is analyzed for Korean small-medium manufacturing enterprises and it us checked productivity improvement and requirement facts impede productivity improvement. It is expected to contribute much productivity improvement through a new established model of production management system and technique or tool for small-medium manufacturing enterprises in Korea.

• Korea Journal of Hospital Management
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• v.19 no.2
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• pp.22-33
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• 2014

The purpose of this study was to support for quality improvement of educational curriculum on hospital administrator through the comparison of competence of new employee and need of field experts based on NCS. The participants of this study were implemented the self-report survey about competency and need on job skills of hospital administrator. According to the comparison, it is defined the point that is needed curriculum improvement and the competency gap between hospital and university hospital. This is support to be establish the base for the qualified education and training program for hospital administrators. NCS is useful as standardized tool for identify the gap between need and competency and as suggestion for education improvement of hospital administrator.

• Journal of Fisheries and Marine Sciences Education
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• v.22 no.4
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• pp.633-646
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• 2010

The purpose of this study was to actually analyze students' sociability using sociometry and effectiveness of students' sociability improvement. To accomplish this purpose, subjects of this study were selected as follow. First, how students' sociability style are actually identified. And second, when teachers give additional concern, opportunity, care, praise to experiment group(reject, isolate, neglectee), what is the effectiveness of students' sociability improvement. As sampling, from fourth to sixth grades 270 students(215 control group, 55 experiment group) of 8 classrooms of 8 elementary schools were sampled. As a tool of investigation, questionnaires about students' sociability style and effectiveness of sociability improvement had made by researcher of this study were used. And as processing of data, ANCOVA were used. The result of this study is as follow. When teachers gave additional concern, opportunity, care, praise to experiment group(reject, isolate, neglectee), students' sociability were improved. In other words, student's self-concept, proactive behavior, human relationship were improved significantly.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.239-241
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• 2012

The major industrialized nations have continued to develop industrialized construction techniques based on automated production processes in factories, and are applying them to a wide range of building. However, the unit modular construction system has had a shorter history of development and application in Korea compared to advanced countries, and consequently, Korean modular builders have a relatively poor technical capacity. So this study is draw a conclusion on the target of priority improvement for idea creation. It study on the enhancement of the functionality of the tool for assemble of Unit Modular that choose the enhancement of the functionality through the analysis of function on the three-level of functional definition and classification, functional arrangement, functional appraisal.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.6
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• pp.122-128
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• 2015

Recently, as the demand for high efficiency, multi-function machine tools has increased, domestic machine tool industries are investing in research and development for Gantry-Type Machining centers. In this thesis, for the purpose of evaluating machining accuracy and designing a machine tool structure, a simplified model of the main frame is suggested. The results show the general characteristics of the optimum design, and the approach is shown as practicable for the preliminary design analysis and improvement of a conceptual design of a Gantry-Type Machining center. This paper's results are expected to improve the static characteristics of Gantry-Type Machine centers. The three-dimensional finite element models proved that the modeling method might be applied to real machine tool structures.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.93-98
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• 2004

A reasonable analysis of cutting force in end milling may give much advantage to improvement of productivity and cutting tool life. In order to analyze cutting force, the cutting dynamics was modelled mathematically by using chip load, cutting geometry, and the relationship between cutting forces and the chip load. Specific cutting constants of the cutting dynamics model were obtained by average cutting forces, tool diameter, cutting speed, feed, axial depth, and radial depth of cut. The effects of the cutting conditions on the specific cutting force constants in milling were studied. The model is verified through comparisons of model predicted cutting forces with measured culling forces obtained from machining experiments

• Journal of the Korean Society for Heat Treatment
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• v.7 no.4
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• pp.318-327
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• 1994

According to conventional nitriding of tool steels, it was very difficult to produce a high surface hardness. This study has been conducted to investigate the influence of initial structures on the nitriding characteristics of tool steels in gas-nitrided for the improvement in surface hardness. The specimens (SACM645, STD61 steels) have been quenching and tempering at various temperature and then gas-nitrided for 30, 45 and 60hr at 500, 530 and $550^{\circ}C$ respectively in gasatmosphere of 30%$NH_3-70%N_2$ As hardness of initial structure was higher, the nitriding layer was deeper and hardness of the nitriding layer was higher. Deeper nitriding layers was due to higher diffusion rate by fine initial microstructure. Also the reason of high surface hardness was associated with formation of dispersed fine carbonitrides of nitrides.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.389-394
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• 1993

Die making process is classified into design,manufacturing,polishing,assembly, and performance test. Die polishing is not a machining process by cutting edge of tool, but it is finishing by relative cutting movement under the surface contact between grinding particles and workpiece, and this process comprised 30~40% of total manufacturing hours. However, die polishing process is still performed by the skilled workers. Now a days, it is very difficult to secure skilled workers due to the hardworking environment and this situation will be getting worse in the future which has great difficulty of dies and molds industries.This process has the common problem on the elimination of tedious manual polishing among the tool making industries. Therefore this study is aimed at the development of an automatic polishing attachment which could be attached onthe spindle of CNC machine tool and controlled by the NC program data created by CAD/CAM system. As a result, this study will contribute the realization of automatic fine polishing process and improvement of quality level of dies and molds.