• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.2
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• pp.209-216
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• 1992

Deafs train articulation by observing mouth of a tutor, sensing tactually the motions of the vocal organs, or using speech training aids. Present speech training aids for deafs can measure only single speech parameter, or display only frequency spectra in histogram of pseudo-color. In this study, a speech training aids that can display subject's articulation in the form of a cross section of the vocal organs and other speech parameters together in a single system is to be developed and this system makes a subject know where to correct. For our objective, first, speech production mechanism is assumed to be AR model in order to estimate articulatory motions of the vocal organs from speech signal. Next, a vocal tract profile model using LP analysis is made up. And using this model, articulatory motions for Korean vowels are estimated and displayed in the vocal tract profile graphics.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.1016-1020
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• 2001

The spinning is a very effective manufacturing technology for short production runs in a variety of sizes and shapes, because it can form the cross-section or tubular parts various shapes. However extensive experimental and analytical research has not been carried out. In this study, and fundamental experiment was conducted to improve productivity with process parameter such as tool path, angle of roller holder(a), feed rate(v) and corner radius of forming roller(Rr). These factors were selected as variables in the experiment because they were most likely expected to have and effect on spring back. The clearance was controlled in order to achieve the precision product which is comparable to deep drawing one. And also thickness and diameter distribution of a multistage cup obtained by shear spinning process were observed and compared with those of a commercial product produced by conventional deep drawing.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.292-294
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• 2006

The aluminum Subframe for automobile chassis part was developed using hybrid process, i.e. extruforming, press stamping and MIG welding. To achieve a 30 % weight reduction compared with convensional steel subframe keeping satisfactory performance, the design of cross-section of extruforming part was introduced, then forming simulation was performed and the final design was determined. In addition, we tried to estibilish optimun aluminum welding conditions for good penetration depth and few pore defect, finally the prototype of aluminum subframe was assembled using MIG welding method. Furthermore, we will adapt this technology to mass production and apply to the other chassis parts.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.746-751
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• 1991

Deafs train articulation by observing mouth of a tutor. sensing tactually the notions of the vocal organs, or using speech training aids. Present speech training aids for deafs can measure only single speech ter, or display only frequency spectra in histogrm or pseudo-color. In this study, a speech training aids that can display subject's articulation in the form of a cross section of the vocal organs and other speech parameters together in a single system Is aimed to develop and this system makes a subject to know where to correct. For our objective, first, speech production mechanism is assumed to be AR model in order to estimate articulatory notions of the vocal tract from speech signal. Next, a vocal tract profile mode using LPC analysis is made up. And using this model, articulatory notions for Korean vowels are estimated and displayed in the vocal tract profile graphics.

• Journal of Radiation Protection and Research
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• v.26 no.3
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• pp.231-236
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• 2001

A brief introduction is presented on the radiation safety studies at Tohoku University Cyclotron & Radioisotope Center. Studies on two subject are described; (1) measurement of the thick target neutron yield and radioisotope production / activation cross section for ten's of MeV neutrons and ions using K=110 Tohoku University cyclotron to provide basicdata for accelerator shielding, and (2) development of techniques for high sensitive radiation detection and profile measurement using an Imaging Plate which is a high sensitive two-dimensional radiation sensor. Application of the Imaging Plate techniques to localization of very weak radioactivity and to neutron profile measurement is described.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.651-654
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• 2001

In the dismantling process of nuclear spent fuels, the spent fuel rod cutting process, followed immediately by the decladding process, performs the cutting the spent fuel rods to a proper length for fast decladding operation. In this paper, we analyzed the chemical compositions, mechanical properties, and physical characteristics for SUS and zircaloy tubes in order to identify the feasibility of cutter-blade type in cutting SUS and zircaloy tubes. It is considered that material, shape and angle, and heat treatment for fabricating the highly durable cutter blade and also it is investigated that the round-shape sustenance of cross-section, amount of debris production, and fire occurrence for measuring the cutting performance on SUS and zircaloy tubes, spent fuel rod cutting device is designed to be operated automatically through the remote control system for use in Hot Cell(radioactive) area and the electro-driven mechanical parts are modularized for easy maintenance. Results from various experiments confirm the efficiency of this device.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.416-421
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• 1997

This study presents a way to construct 3D shape in STL format from 2D slice data. Nowadays ahape reconstruct has been done in many ares, the application of this method is important especially in Reverse Engineering which reconstructs original shape from cross-section data. Current RP (Rapid Prototyping) is used not only for the verification of a part designed but also for the production and tooling in more effective way. In RP technology, data should be prepared in STL format. In this paper, the way to make 3D shape data in STL format form 2D slice data is described which can be used to reconstruct an original shape in RP equipment.

• Laser Solutions
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• v.2 no.1
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• pp.51-60
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• 1999

In this paper, weldability and formability of Tailored-Blank (TB) and the structural impact testing of bump beam were investigated to apply TB to automobile bumper beam. The optimal $CO_2$ laser welding condition for TB of SPFC and SPRC steel plates with different thicknesses was obtained. Before welding, the cross section of butt joint was prepared only by shearing without milling process. Real type bump beam was produced by two kind of forming processes such as roll-forming and press-forming, and the good formability of TB was obtained. Impact test results of bump by using pendulum and barrier were satisfied the impact regulation of bump. Finally. It may be confirmed that laser welded TB is well-balanced material in both weight reduction and production cost of automobile bump.

• Journal of the Korean Society for Heat Treatment
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• v.16 no.1
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• pp.16-25
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• 2003

Recently, semi-solid forming (SSF) Process has been applied in many automobile parts for improved weight reduction, better environmental protection and energy savings. SSF process was well developed for high volume production of light weight aluminum components. In this paper, knuckle has been manufactured by SSF and then the microstructures and mechanical properties were investigated followed by various heat-treatment conditions. It was found that the examined microstructure was equiaxed at the whole cross-section area.

• KDI Journal of Economic Policy
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• v.37 no.2
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• pp.40-63
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• 2015

Anthracite exports have special value within the DPRK's economy. In this paper, we focus on what determines the DPRK's anthracite exports to China. We use panel data consisting of cross-section data from 30 provinces in China and quarterly time-series data from 1998 to 2013. Controlling for all other variables that affect anthracite imports, the variable for steel production in China is robust and statistically significant. This is consistent with on-site interviews which indicate that much of North Korean anthracite is consumed by China's steel industry. This implies that the North Korean authorities need to make adjustments to the foreign trade structure, as the import demand for anthracite in China may decline further.