• Journal of Computational Design and Engineering
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• v.2 no.4
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• pp.206-217
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• 2015

This paper presents a complete S-shape feed rate scheduling approach (CSFA) with confined jerk, acceleration and command feed rate for parametric tool path. For a Non-Uniform Rational B-Spline (NURBS) tool path, the critical points of the tool path where the radius of curvature reaches extreme values are found firstly. Then, the NURBS curve is split into several NURBS sub-curves or blocks by the critical points. A bidirectional scanning strategy with the limitations of chord error, normal/tangential acceleration/jerk and command feed rate is employed to make the feed rate at the junctions between different NURBS blocks continuous. To improve the efficiency of the feed rate scheduling, the NURBS block is classified into three types: short block, medium block and long block. The feed rate profile corresponding to each NURBS block is generated according to the start/end feed rates and the arc length of the block and the limitations of tangential acceleration/jerk. In addition, two compensation strategies are proposed to make the feed rate more continuous and the arc increment more precise. Once the feed rate profile is determined, a second-order Taylor's expansion interpolation method is applied to generate the position commands. Finally, experiments with two free-form NURBS curves are conducted to verify the applicability and accuracy of the proposed method.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.72-81
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• 2016

There can be included a variety of uncertainties in all measurement results whether we can perceive or not on the causes. These uncertainties may end up in lowering the reliability of measurement results and also deteriorate the level of quality. For the purpose, we tried to combine the strengths of measurement uncertainty and measurement system analysis together to present a practical flowchart so as to verify those potential variation factors in general measurement processes. As a case study, we did an experiment and gathered data on the length between two holes of an engine cylinder head which is a core part for vehicles with a coordinate measuring machine and estimated nine uncertainty factors of it. Consequently, it was identified that the four primary factors among the nine which were related to the measurement standard, random errors or spread of the repeat measurements, differences between the coefficients of thermal expansion and the environment especially had been the influence around the laboratory. Since it is impossible to analyze the equipment and appraisal variations respectively through the only measurement uncertainty, we have used the measurement system analysis following the flowchart. Showing the result of being just about 0.5% lower for the appraisal variation, and the equipment variation occupied about 7% for the total Gage R&R. Through this research, we have come to a conclusion that much more detail analysis on variation factors can be possible to be identified in measurement processes by using the developed flowchart which is composed of measurement uncertainty and measurement system analysis. Therefore, we expect engineers who are involved in quality and measurements to utilize this developed method.

• Journal of Animal Environmental Science
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• v.2 no.2
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• pp.155-164
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• 1996

The objective of this study was to estimate the investment limit in equipment capital by Capital Recovery Method. The data used was collected from 23 Hanwoo(Korean Native Cattle) farms in 1994. The necessary time for herd size expansion was average 5 years from opening(9.7 heads) to 50 heads, 4 years from 50 to 100heads, 3 years from 100 to 150 heads, and 2 years from 150 to 200 heads, respectively. It took 14 years from opening to 200 heads of herd size. The debts for fattening cattle farms were 15.2million won for the size of 50 heads, 37.1 million won for the size of 100 heads and 89.0 million won for the size 200 heads, respectively. Average rates of debt interest were 5.1 % 7.2 and 10.8, correspendingly. As the hear size increased, debt interest rates also increased due to government funds limit. The investment limits in equipment capital perfarm household were 77.7 million won for 50 heads, 135.1 for 100 heads, and 294.3 for 200 heads for 5,500 won per kg liveweight, 70.7 million won for 50 heads, 122.6 for 100 heads and 269.3 for 200 heads for 5,000 won per kg liveweight, 63.6 million won for 50 heads 110.0 for 100 heads and 244.2 for 200 heads for 4,500 won per kg liveweight.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.12
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• pp.34-40
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• 1999

In conventional color television systems color edges of highly saturated color pictures are deteriorated because of bandwidth limitation of the color-difference signal. In this paper a modified hue-weighted luminance demodulation method with low noise is proposed for the edge correction. The weighting coefficients are given by ratios of the gadient of color-difference signal to the gradient of band-limited luminance signal. Proposed method is theoretically complete for the 1st order lowpassed color-difference signals and well separated luminance/chrominance signal. Noise reduction technique is also considered because of impulse noise generation in the gradient ratio processing of noisy pictures. In computer simulation with noisy pictures proposed technique gives a visual effect of the bandwidth expansion and detail improvement in highly saturated color edge area.

• Composites Research
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• v.29 no.3
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• pp.104-110
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• 2016

This paper reports a novel method for simultaneous exfoliation of graphene and dispersion of carbon nanotube by using intercalation method. In common, graphene flake and carbon nanotubes can be produced through individual exfoliation or debundling process, but the process require significant amount of time. Here, potassium sodium tartrate was thermally intercalated into graphite and carbon nanotube bundle for simultaneous exfoliation and dispersion of graphene and carbon nanotubes. We confirmed expansion of interlayer distance via XRD, and also found that oxidation level of the exfoliated materials were significantly low (below 8.3 at%). The produced materials are fabricated in to conductive composite film via vacuum filtration and spray deposition to show enhancement of conductive properties.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.735-743
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• 2015

The major component with a significant impact on the thermodynamic efficiency of the organic Rankine cycle is the turbine. Many difficulties occur in the turbine design of an organic Rankine cycle because the expansion process in an organic Rankine cycle is generally accompanied by a dramatic change in the working fluid properties. A precise preliminary design for a radial inflow turbine is hard to obtain using the classic method for selecting the loading and flow coefficients from the existing performance chart. Therefore, this study proposed a method to calculate the loading and flow coefficient based on the number of rotor vanes and thermodynamic design requirements. Preliminary design results using the proposed models were in fairly good agreement with the credible results using the commercial preliminary design software. Furthermore, a numerical analysis of the preliminary design results was carried out to verify the accuracy of the proposed preliminary design models, and most of the dependent variables, with the exception of the efficiency, were analyzed to meet the preliminary design conditions.

• Journal of the Korea Computer Industry Society
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• v.7 no.3
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• pp.135-144
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• 2006

According th expansion of computer technology and fast spread of network today, change is accelerated to electronic filing document in information carrier that use existent paper. Accord ingly, it became very important issue that create electronic filing document, and manage information that is included to electronic filing document. XML is expected to act important role in electronic commerce, electronic library, construction of point application system of imagination college and so on furthermore as well as can be complicated in Internet and ease storage of structured document data, administration, search. It is not easy work that peon makes out this XML document. This dissertation is research about edit method to make out XML document as more easy and convenient. Introduced concept that input XML document using document form for this, and separated input process by process and process that make out actuality XML document using made XML document form that make XML document form. Such detached input method can improve efficiency of XML input because can input easily XML document if use XML document form that offer input person who do not know well about XML specialist or system.

• The Journal of Industrial Distribution & Business
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• v.11 no.5
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• pp.35-44
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• 2020

Purpose: The purpose of this study is to present a plan to expand the employment of the elderly in Small business as one of the ways to solve the problem of the supply and demand of the company due to the aging population and the problem of the elderly poverty. Research design, data and methodology: The method of this study is a qualitative research method, and the researcher visited a small and medium-sized company directly and collected data by conducting an in-depth interview with a business owner. The interview period was conducted on a total of 15 business owners from November 5, 2013 to November 18, 2013. Results: First, the reason why companies hire the elderly is because they are suitable people, and the reason why they are not employed is because the elderly are not suitable. Second, it was found that the most recruiting paths continued to work after retirement. Third, the strengths of the elderly in their businesses were diligence, integrity, leadership, wisdom, warmth, and skill. Disadvantages the elderly in their businesses include wanting to be treated as an adult, poor productivity, poor accuracy, and health risks. Fourth, in case of hiring the elderly, they were considering convergence with young employees, and it was suggested that there are no difficulties in being an elderly because the companies hiring the elderly use the elderly according to the characteristics of the elderly. Fifth, It is realistic to actively utilize the employment system after retirement. Sixth, it was found that, unlike young people, it is not easy to recruit people on the Internet, so it is necessary to improve the system. Lastly, some industries clearly distinguished between the jobs of the elderly and the jobs of the young, but in many industries, it was desirable to create jobs for the elderly by harmonizing the main and secondary jobs. Conclusion: Ultimately, the work of the elderly in small and medium-sized enterprises should be reborn as a high-quality job that can solve the poverty of the elderly by working as a regular worker in the enterprise, rather than simply working for the elderly.

• Korean Journal of Cognitive Science
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• v.19 no.4
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• pp.499-517
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• 2008

In this paper, we propose an effective emotion feature extraction method for Korean and evaluate their availability in sentiment classification. Korean emotion features are expanded from several representative emotion words and they play an important role in building in an effective sentiment classification system. Firstly, synonym information of English word thesaurus is used to extract effective emotion features and then the extracted English emotion features are translated into Korean. To evaluate the extracted Korean emotion features, we represent each document using the extracted features and classify it using SVM(Support Vector Machine). In experimental results, the sentiment classification system using the extracted Korean emotion features obtained more improved performance(14.1%) than the system using content-words based features which have generally used in common text classification systems.

• Journal of Korea Multimedia Society
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• v.9 no.10
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• pp.1322-1331
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• 2006

Concurrency control is one of the important factors to maintain consistent conditions of a game because most participants of the game should be shared information to play the game through a distributed network system. replay delay times should establish in every event and the received event should be saved and performed simultaneously for Concurrency Control. However, it is not easy to practice the event with same speed in environment having various moving speed. Therefore, expansion have to be provided. In other words, one of the most important factors of a game's efficiency is the process of bandwidth and delay. the process of concurrency control method based on scalable prediction for Multi-platform games would minimize the loss rate of a event and then would improve the interaction capacity of a game. It also might get reliability between clients. This paper analyzes some problems in terms of a layout of a game that integrates a cable and a wireless system. In addition, this paper provides methods to expand bandwidth and delay that might be an obstacle of a On-line game and to ensure reliability between a server and a client.