• Journal of Information Technology Applications and Management
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• v.19 no.2
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• pp.97-116
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• 2012

Since 2008 when IPTV service entered the broadcasting market, the competition among interactive broadcasting media has been growing more and more fierce. To make a market strategy under the harsh competition, this study tried to make an IPTV customer segmentation based on the characteristics of interactive broadcasting media. From previous literature, this study drew five characteristics of interactive broadcasting media : ease of use, two-way communications, active control, variety of content, and economic efficiency. Two-step clustering based on these characteristics identified four customer segments. There were statistically significant differences in the five characteristics among the customer segments. This study profiled the customer segments and proposed competitive strategies for each customer segment.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1236-1240
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• 2004

Thermal vacuum test for satellites should be performed before launch to verify the feasibility of satellites' operation in a harsh space environment which is represented as an extremely cold temperature and vacuum condition. A large space simulator(${\Phi}8m{\times}L10m$) has been demanded to accomplish the thermal vacuum test for the huge satellites designed in compliance with the national space program of Korea. In this paper, the design and calculation of thermal shroud which is the core part of large space simulator were discussed. The characteristics of the large space simulator being constructed at Korea Aerospace Research Institute(KARI) were depicted.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.510-514
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• 2002

The 3-dimensional measuring machine by using an ultrasonic sensor is used one of the NDE(Non Destructive Examination). It is applied to the inspection of pipelines, boreholes, pressure vessel and tank, and so on. In particular when a harsh environment prohibits the use of moving mechanical parts. The 3-dimensional measuring machine by using an ultrasonic sensor, which measure 1-dimensional information and 2-dimensional information simultaneously from a target of inspection, and then reembody 3-dimensional information. So we can find the situation in progress and predict remaining life and corrosion without destructive examination. It's a point of excellence that the 3-dimensional measuring machine is portable.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.196-200
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• 2005

Piezoelectric underwater acoustic transducer is a kind of device for underwater detection working as not only an actuator but also a sensor. The technique that can predict acoustical characteristics of transducer is important for robust design of transducer in harsh underwater environment. This paper represents the dynamic analysis of piezoelectric acoustic transducers based on finite element method through USAP software. Two dimensional model of Tonpilz transducer and three dimensional model of Flextensional transducer are generated for the dynamic analysis and some results obtained by USAP are compared with those by ANSYS.

• Korean Journal of Veterinary Research
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• v.53 no.4
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• pp.207-210
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• 2013

Fifteen dry dentate and complete mandible samples from the White Rasquera goat breed were studied for symmetry. Thirty-one landmarks were digitally located on the images of the lateral and medial aspects of each hemimandible. Distances between these landmarks allowed the evaluation of the whole hemimandible and also the neural mandible. In the studied samples, the mandible was rather symmetrical, especially in the medial neural part, and in general, there was no side dominance. Only the diastema differed significantly between the sides, and this was related to the rostral part (incisive arch). The incisive region was the least symmetrical region of the caprine mandible, indicating a modular structure more conservative for the neural part. If unsigned asymmetry is interpreted as a measure of developmental stability, then the studied breed presented a marked ability to develop in good fitness despite the harsh environment. The measurements presented here can also be used as a reference for researchers designing experimental studies, especially on mandibular catch-up growth, and as an aid for zooarchaeologists comparing results from dead animals with those from living goat populations.

• Journal of Korean Society for Quality Management
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• v.27 no.4
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• pp.266-279
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• 1999

Today, Companies are facing the harsh realities of a competitive environment. This is no time for revolutionary change. Instead, Companies are instituting revolutionary change meant to have impact within a very short time frame. Bold steps are required to lead the industry into a future of improved efficiency and significant productivity gains. GE, as well as Intel, Motorola, and other companies adopted a program called Six Sigma, in order to make fundamental changes in the way the company operated to fulfill customers'expectations. Six sigma reduces the occurrence of defects from a 3 sigma level of 66,800 defects per million to a 6 sigma level-less than 4defects per million. The goals and metrics of the company's Six Sigma process clearly have had a positive effect on customer satisfaction and customer perception of the company.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.142-144
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• 2003

The suspension insulators are subjected to harsh environment in service for a long time. Long term reliability of the insulators is required for both mechanical and electrical performances. We studied HRB characteristics to find out a deformation of suspension porcelain with alumina contents. These experimental results show that HRB intensity was affected severely by alumina contents, and the propagation properties was affected mainly by a distribution and shape of micro pores on porcelain samples.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.1
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• pp.120-130
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• 1993

In the analysis of automobile exhaust system, the exciting forces from the engine determine the dynamic behavior of the system and the dynamic characteristics influence the riding quality. Therefore, the identification of the force in numeric value is quite important for the vibrational reduction. However, the value is difficult to obtain by experiments due to harsh conditions around the engine. In this research, an optimization technology is adopted to evaluate the exciting forces. An experimental method is conducted for the verification of the finite element modeling. Displacements on the end of the exhaust system are measured under the idling environment. cost function is set up to minimize the differences between the displacements of the numerical simulation and the experiment. Design variables are the components of the exciting forces. That is, optimization is utilized to estimate the forces with existing data. Excellent estimations have been calculated efficiently and the information is used again for the forced vibration of the exhaust system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1248-1252
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• 2014

In this study, we designed a signal processing module using a radiation hardened technology that can be applied to the all measurement sensors inside nuclear power plant containment. Also, for verification that it can be used for high-level radiation environment (Harsh environmental zone inside containment of NPP), we carried out evaluation tests for a designed module using a $Co^{60}$ gamma-ray source up to 12 kGy(Si). And, we had checked radiation hardening level that it has been satisfied up to 12 kGy(Si).

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.10
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• pp.37-42
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• 2014

This paper discusses study of sensorless control of a variable speed switched reluctance motor (SRM) for electric AC compressors on electrical vehicles. A typical SRM drive requires a position sensor such as an encoder or hall sensor to measure the angular rotor position. However, harsh environment in electrical AC compressors for electric vehicles makes it difficult to use the position sensor in their motor drive system. Therefore, a sensorless control scheme for electric compressor motors utilizing magnetic characteristics of SRM with respect to position angle and phase current is proposed. The overall variable speed SRM drive with position sensorless control scheme has been modeled using Matlab/Simulink software and closed loop current control simulation is presented to validate the proposed sensorless drive control.