• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.461-464
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• 2014

As smart phones have became popular in recent years, use rate of smart phones application of mobile subscribers is now gradually increasing. Smart phones have a considerable effect on real life of users. Especially, mobile payment service using smart phones is outstanding in convenience because of its simple way to check out online. Therefore, in this paper, the database was designed for inquiring and making pre-order for take-out products based on connivence. This paper offers pre-order design to have order information standardized, menus which store owners can register and manage, and statistical data based on sales. It can be cost and time-efficient by using integrated pre-order system across all franchises. If this take-out pre-order system becomes more widely available, it will increase profit for both users and franchises due to cost and time efficiency.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.1
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• pp.23-33
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• 2002

A hysteresis control is widely used to control output current of inverter. A hysteresis bandwidth is affected by system parameters such as source voltage, device on/off time, load inductance and resistance. The frequency limiter is used to protect switching devices overload. In the conventional hysteresis controller, a lock-out circuit with D-latch and timer is used to device protection circuit. But switching delay time and harmonic components are appeared in output current. In this paper the performance of lock-out circuit is tested, and new circuit for switching device fault protection is proposed ad it's performance is simulated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.04a
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• pp.425-428
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• 1994

Non-uniform minute deformation of a cylinderical workpiece resulted from the heat treatment process prior to the grinding makes it diffeclt to control the approaching feedrate of a grinding wheelto a workpiece optimallywithout on-site detection of the grinding states in the plunge grinding. The 4-stage model of the plunge grinding process is proposed according to the state of contact between grinding wheel and workpiece ; precontact, partial contact, entire contact and spark-out. Despite of being scrious to the precision of workpiece finished, the duration of spark-out is determined empirically. The purpose of this research is to develop a monitoring/control system for saving non- production time and setting the optimal spark-out time based on sensor information in the plunge grinding using AE and ultra sonic sensor.

• Journal of the Korean Society of Safety
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• v.14 no.2
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• pp.155-162
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• 1999

reliability from components reliability. In this case, it assumes that components failure is mutually independent, but it may not true in real systems. In this study, the mean cost per unit time is computed as the ratio of mean life to the mean cost. The mean life is obtained by the reliability function under power rule model. The mean cost is obtained by the mathematical model based on the inspection interval. A heuristic method is proposed to determine the optimal number of redundant units and the optimal inspection interval to minimize the mean cost per unit time. The assumptions of this study are as following : First, in the load-sharing k-out-of-n:G system, total loads are applied to the system and shared by the operating components. Secondly, the number of failed components affects the failure rate of surviving components as a function of the total load applied. Finally, the relation between the load and the failure rate of surviving components is set by the power rule model. For the practical application of the above methods, numerical examples are presented.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.06a
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• pp.119-128
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• 1994

Until recently, Stamping tool manufacturing depend on skilled designers and technicians, because it has many parameters. So, Try-out time not controlled. We now apply CAE, preliminary experiment, material database and automated stain measurement in stamping tool manufacturing for concurrent engineering that decreases product development circle time, saves cost, improves product reliability. Automated strain analysis and measurement environment gives very accurately informations to technicians of stamping tool manufacturing. They analysed the part in problem and appled to results in Try-out step.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.3
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• pp.250-260
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• 2004

This study considers a linear connected-(r,s)-out-of-(m,n):F lattice system whose components are ordered like the elements of a linear (m,n )-matrix. We assume that all components are in the state 1 (operating) or 0 (failed) and identical and s-independent. The system fails whenever at least one connected (r,s)-submatrix of failed components occurs. The purpose of this paper is to present an optimization scheme that aims at minimizing the expected cost per unit time. To find the optimal threshold of maintenance intervention, we use a genetic algorithm for the cost optimization procedure. The expected cost per unit time is obtained by Monte Carlo simulation. The sensitivity analysis to the different cost parameters has also been made.

• International Journal of Advanced Culture Technology
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• v.8 no.3
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• pp.325-333
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• 2020

In the past, eating outside was usually the purpose of eating. However, it has recently expanded into a restaurant culture market. In particular, a dessert culture is being established where people can talk and enjoy. Each consumer has a different tendency to buy chocolate such as health, taste, and atmosphere. Therefore, it is time to recommend chocolate according to consumers' tendency to eat out. In this paper, we propose a chocolate recommendation application based on the tendency to eat out using data on social networks. To collect keyword-based chocolate information, Textom is used as a text mining big data analysis solution.Text mining analysis and related topics are extracted and modeled. Because to shorten the time to recommend chocolate to users. In addition, research on the propensity of eating out is based on prior research. Finally, it implements hybrid app base.

• Journal of Korean Home Economics Education Association
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• v.13 no.3
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• pp.13-22
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• 2001

The Purpose of this study is to enhance the efficiency of clothing-making units in the textbook of Home Economics for the high school students. I handed out a research paper with several questions to 75 teachers and 87 students to find out the realities of the education. There are several problems of making clothes at class: lack of time, appropriate equipment and efficient learning material. To solve these problems. I made a half-sized skirt kit utilizing OPTI Tex. a type of CAD in fashion design and copied it by silkscreen. and let the students use it. Both of the teachers and students showed positive response to the newly made kit of my own. saying that \"it is very handy to prepare and it\`s very helpful to figure out how to make skirt. \" Using the kit. we could reduce the time to make clothes by about 60 % and do well in the classroom without any sewing machines.

• Proceedings of the Korean Reliability Society Conference
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• 2004.07a
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• pp.201-206
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• 2004

The linear consecutive-k-out-of-n:F system consists of n components ordered linearly and fails if and only if at least k consecutive components fail. We assume that the failure times of components are independent and identical exponentially distributed. This paper develops a model to calculate the expected cost per unit time of a linear consecutive-k-out-of-n:F system. The optimization problem to find the system structure parameter k to minimize the expected cost per unit time is considered.

• Elastomers and Composites
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• v.34 no.4
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• pp.332-340
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• 1999

Hydrogenations of BR and NR performed by a noncatalytic method using p-toluenesulphonylhydrazide were carried out by reactive processing. The experimental procedures for carrying out the reaction were established. Two steps comprising premixing of the rubber with TSH followed by hydrogenation in compression mould were proved to be suitable. The percentages of hydrogenation attained by reactive processing were higher than those of the reaction carried out in solution at the same [TSH]/[C=C] ratio, reaction temperature and time. In-creasing the reaction temperature and reaction time resulted in increases of the percentage of hydrogenation. For BR, the maximum percentage of hydrogenation obtained was 36% at [TSH]/[C=C]=1/1.5. For NR, the highest percentage of hydrogenation was 34% at [TSH]/[C=C]=1/1.5. Cis-trans isomerisation was also observed to occur during hydrogenation of both BR and NR. Thermal stabilities of the hydrogenated BR and NR were shown to improve over those or the unhydrogenated counterparts.