• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.254-258
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• 2008

Dimensional accuracy is very important quality in micro forged part, especially on forged part. Dimension of forged part is changed continuously during forging process. Loading, unloading and ejecting stage affects dimensional of the forged tool. The elasto-plastic material model for billet and elastic model for die were used to analyze these changes. At same time, the calculated results were compared and analyzed by the experiment on same conditions. From the experimental and analytical studies, we can calculated the amount of difference between die and forged part, that is 0.49% based on the die dimension. The dimensional change is smaller than that of general sized-forged part,0.6%.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.1964-1968
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• 2007

The river water heat source heat pump has the advantage in the performance compared to air source heat pump. Although its better performance, the large temperature difference between load and source makes system performance worse by nature. In this study, 2-stage compression is considered as the solution of this problem. Generally, heat pump is designed for maximum capacity rate, but it actually operates at part load condition in many cases. Therefore, an information on the part-load character is very important in view of the system overall performance. In this study, part-load performance tests of a R134a 2-stage compression heat pump were carried out over the river water and supply heating water temperature changes. The experimental results show that the system performance is influenced by the part load rates, river water temperature, load temperature, etc.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.399-406
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• 2001

This study describes the geometric characteristic and the 5-axis machining method of end mill body with insert tip. The geometry of end mill body is consisted of the flute part and the insert tip part. Thus, this study defines the flute part as ruled surface with constant helix angle and the insert tip part as rectangular plane on general direction. The geometric algorithm and the 5-axis NC part program were calculated by our programmed software and a sampled end mill body was machined on 5-axis machining center equipped with two index tables. The machined end mill body with insert tip was very agreeable to the designed end mill body with insert tip. Thus, the method proposed in this study may be very useful for the machining of end mill body with insert tip.

• Journal of the Korean Society of Food Culture
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• v.19 no.6
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• pp.611-619
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• 2004

This study was conducted to investigate the job characteristics of foodcoordinator. 34.56% of subjects have the part of food as a speciality in college or University. 50.67% of subjects don't have any licence which is related with food. 30.67% of subjects have 1-3year or under career in the food part. Upon investigation the educational period by the period of career in food part, Subjects who had 5 year over career in the food part have 60.34month educational period. Upon investigation the speciality in college or University by the period of career in food part, 58.33% of 5 year over career in the food part respondents have food speciality in college or University. As the period of career in food was increased, the importance of cooking was increased.

• The Journal of the Korea Contents Association
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• v.2 no.2
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• pp.98-102
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• 2002

In this paper i offer a new part-of-speech tagging method for Korean, it can solve difficulty of statistical data acquisition and ambiguities due to same part-of-speech stream input and make good use of the Corpus. This method can solve that the corpus don't have huge. This method uses pattern information about part-of-speech among eojols and constraint-rules in order to perform part-of-speech tagging. The Constraint-rule is used to select appropriate part-of-speech pattern.

• Journal of Applied Reliability
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• v.12 no.3
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• pp.225-238
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• 2012

In this paper determined is the quantity of repairable concurrent spare parts(CSP) of a new equipment system to maximize the operational availability under budget constraint and cannibalization allowed. When a part fails, the part is replaced and the failed part is repaired for later use while cannibalization is allowed. The failure of a part is assumed to follow a Poisson process and the availability in CSP is defined. The solution procedure consists of two parts. Firstly, a mathematical model is developed under the assumption that the failure rate is constant during the CSP period and cannibalization is not allowed. Secondly, proposed is a simulation search procedure which improves the heuristic solution to the near optimal solution in a reasonable amount of time under the assumption that the cannibalization is allowed.

• Advances in materials Research
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• v.3 no.2
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• pp.91-103
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• 2014

A study that demonstrates how to investigate the molded part quality and the consistency of injection process based on the rheological concept is proposed. It is important for plastic material whose melt viscosity is variable with respect to the processing condition. The formulations to couple the melt viscosity with injection pressure and fill time are derived first. Taking calculations of the measured pressure and the time by using these formulations, the melt viscosity in injection process can be determined on machine. As the relation between the injection speed and the melt viscosity is constructed, the influences of the setting parameter of injection machine on the molded part quality can be investigated through evaluating the state of the melt viscosity. In addition, a pressure sensor bushing (PSB) designed with a quick installation feature is also provided and validated. The results show that a higher injection speed improves the tensile strength of the molded part but also the consistency of the molded part quality. This work provides an alternative to evaluate the molding quality scientifically.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.7
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• pp.327-333
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• 2002

In this study, we developed a snoring detection algorithm that detects snores automatically. It consists of preprocessing and snoring detection part. The preprocessing part is composed of a noise removal part using spectrum subtraction, and segmentation part, and computation part of temporal and spectral features. And the snoring detection part decides whether detected blocks are snores with BPNN(Back-Propagation Neural Network). BPNN with one hidden layer and one output layer, is trained with data of 7 subjects and tested with data of 11 subjects of total 18 subjects. The proposed algorithm showed a Sensitivity of 90.41% and a Predictive Positive Value of 84.95%.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.87-90
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• 2004

Telematics is an emerging industrial field made up of the convergence of technologies. The key technologies for Telematics are server-side technology, terminal-side technology, communication-related technology, and positioning technology. Standardization in Telematics is now getting more notice these days. Domestic situation is explained for several related facilities such as ETRI, TTA, and Telematics Standardization Forum. In this paper, we will focus especially on the standard reference model that is the most fundamental framework of Telematics technology standardization. In the reference model, the Telematics system is composed of Telematics client part, communication part, and Telematics server part. The Telematics client part consists of terminal, positioning device, and car electronic devices. Communication part can be composed of various telecommunication channels such as CDMA, WLAN, DMB, WiBro, etc. which can guarantee the seamless two-way communication. Telematics server part is composed of TSP(Telematics Service Provider) server and CP(Contents Provider) servers gathering and managing the various Telematics services. This Telematics reference model is expected to be utilized as the base architecture in developing the technology and standards from now on.

• Proceedings of the KWS Conference
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• 2008.05a
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• pp.14-14
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• 2008