• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.3
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• pp.477-484
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• 1997

This paper describes the build-up force measuring system of 9.9 MN capacity which consists of nine force transducers of each having 1.1 MN capacity. We have specially designed a force transducer for a build-up force measuring system to reduce the uncertainty of a build-up system and to accomodate the new test procedure for a build-up system. It reveals that the relative uncertainty of the force measuring system is less than 1.5*10$^{-4}$ in the ran9e of 1-4.5 MN irrespective of loading direction. The force measuring system may be used to calibrate a 10 MN force standard machine to be used as a large force standard in Korea.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.25-27
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• 2006

This paper proposes a new full ZVS-range asymmetrical half bridge converter. It uses the variable transient current build-up technique with the load variations. The current build-up is accomplished by using the secondary synchronous switch control. Due to the blocking capacitor in secondary side, the voltage applied to leakage inductor varies with the load variations during current build-up period. Therefore, the unnecessary current build-up of leakage inductor current in heavy load condition is prevented and more current build-up in medium and light load condition is achieved for ZVS operation. That is, the variant current build-up with the load variation is accomplished for the ZVS operation. Furthermore, the DC offset of the transformer magnetizing current is also eliminated and the utilization of magnetic core is maximized.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.12 s.255
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• pp.1139-1146
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• 2006

Light Oil Flow Standard System(LOFSS) in Korea Research Institute of Standards and Science(KRISS) was designed for oil flowmeter calibration. In order to extend the flow range from 120 $m^3/h$ to 200 $m^3/h$, the build-up technique was applied with two positive displacement flowmeters as master flowmeter. The master flowmeters were calibrated against with LOFSS, which has 0.04 % uncertainty of flow quantity determination, then the test flowmeter is calibrated against two master flowmeters. For uncertainty analysis, the repeatability of master flowmeters, the variation of the fluid density and the pipe volume due to temperature change were scrutinized. The contribution of each uncertainty factors to the calibrator and the correlation of each factors were discussed. For investigating the feasibility of uncertainty analysis, a turbine flowmeter as a transfer package was tested with LOFSS and two reference flowmeter. The hypothesis test for both results was coincide with a 95 % significant level. This means that the uncertainty analysis procedure of the calibrator is reasonable and the extension of flow range with master meters was carry out successfully.

• Journal of Radiation Protection and Research
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• v.14 no.2
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• pp.37-44
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• 1989

An improved water chemistry technique was studied to reduce radioactivity build-up in reactor coolant system. The technique is convering the current coordinated lithium-boron chemistry regime to the elevated lithium chemistry regime in order to maintain high pH. Correlations between reactor coolant pH and radioactivity build-up were analized by using pH data from domestic PWRs. Consequently, it was founded that high pH chemistry was moer effective for radioactivity build-up reduction than current chemistry regime. This fact had revealed that much portion of reactor coolant corrosion products were nickel ferrite rather than magnetite, and that pH value ranging 7.0-7.4 was appropriate for high-pH chemistry operation.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.6
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• pp.757-764
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• 2000

Statement of the problem. All-ceramic post-and-core restorations offer a number of advantages compared with systems that use metal build-ups. In certain clinical cases, however, fractures at the joint between the post and core build-up have been reported. Purpose. The objective, therefore, is to improve the joint between the post and the core build-up. Material and methods. Three different methods were used to prepare all-ceramic post-and-core restorations; pressing IPS Empress core build-ups to CosmoPost zirconia posts, cement-ing IPS Empress core build-ups to CosmoPost zirconia posts and Celay-milling of zirconia blanks. A series of ten restorations was prepared for each of the three methods. The post-and-core complexes were tested to failure with the load applied perpendicular to the post axis. The load and deflection at fracture were recorded. Results. The highest breaking load and highest deflection were recorded for the cementing technique with values of 25.3 N and $394{\mu}m$, respectively, The corresponding values for the pressed core build-ups and the milled zirconia core build-ups were 22 N and $301{\mu}m$, and 13 N and $160{\mu}m$, respectively. All the differences are statistically significant (p=0.05). Regarding the load-dependence of the deflection, the cemented core build-ups again demonstrated the highest value with $15.5{\mu}m/N$. The difference in the values of $13.6{\mu}m/N\;and\;13{\mu}m/N$ recorded for the pressed-on and milled core build-ups, respectively, were statistically insignificant. Conclusion. In regard to the high fracture resistance of zirconia post, adhesive cementing the core build-up to the post offers a viable alternative to the conventional pressing technique. The elastic bond between the rigid high-strength zirconia post and the core build-up presents an additional advantage.

• Progress in Medical Physics
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• v.10 no.2
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• pp.83-88
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• 1999

Purpose: TLD experiments were set up to measure the dose distribution and to analyze the influence on dose measurement of thin metal plate and solid water phantom. The aim of the present study was to investigate the build-up effect of metal plate loaded on TLD chip and depth dose in the controlled environment of phantom measurements. Materials and Methods: Measurements were done by using LiF TLD-100 loaded by a thin metal plate with the same surface area (3.2$\times$3.2 $\textrm{mm}^2$) as TLD chip. TLD chips loaded with one metal plate from three different metal plate (Tin, Copper, Gold) of different thicknesses (0.1, 0.15, 0.2, 0.3 mm) were used respectively to measure radiation dose. Using the TLD loaded with one metal plate, surface dose and the depth dose at the build-up maximum region were investigated. Results: Using a metal plate on TLD chip increased the surface dose. Surface dose curve shows the dose build-up against equivalent thickness of metal to water. The values of TL reading obtained by using metal plate at depth of build-up maximum are about 8% to 13% lower than those obtained by normal TLD chip. Conclusion: The metal technique used for TLD dosimetry could provide clinicals information about the build-up of dose up to 4.2mm depth in addition to a depth dose distribution. The results of TLD with a metal plate measurements may help with decisions to boost or bolus certain areas of the skin.

• Journal of Technologic Dentistry
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• v.33 no.4
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• pp.313-321
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• 2011

Purpose: The purpose of this study was to compare color parameters of different fabrication method of Lava ceram powder, Lava DVS blocks, IPS e.max ceram and IPS e.max zirpress. Methods: The three available shades(A1, A2, A3.5) of Lava & Kavo zirconia blocks were examined. For each of three colors, three different thickness were tested, 5 times of measurement frequency. The measurements were made using a spectrophotometer equipped with an integrating sphere using the CIE $L^*$, $a^*$, $b^*$ colorimetric system. Results: Lava build-up group and Lava DVS group showed clinically perceived color difference, on the other hand IPS e.max build-up group and IPS e.max zirpress group did not show clinically perceived color difference to shade allowed on core. When the thickness of porcelain veneer increased from Lava and IPS e.max groups, color differences(${\Delta}E$) were decreased. Conclusion: All-ceramic system has color characteristics that clinicians have to consider when selecting materials. Also, manufacturers of different porcelain systems must make every effort to achieve color reproducibility.

• Radiation Oncology Journal
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• v.1 no.1
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• pp.25-28
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• 1983

Anterior and posterior parallel opposed field technique covering entire neck is desirable for elimination of junctional problems in treating upper neck with bilateral parallel opposed fields and lower neck with anterior one field. For good dose distribution in neck, dose in build-up region should be high for anterior field and should be low for posterior field. And so, with 10 MV X-ray, lead absorber was used for anterior field only. The adequate thickness of lead absorber, absorber-skin separation, width of central cord block for posterior field and anterior & posterior field weight were studied using film dosimery. The results are as follows. 1. As the thickness of the lead absorber increased the dose in build-up region increased. 2. As the absorber-skin separation decreased the dose in build-up region increased. 3. The adequate thickness of lead absorber was around 5.6mm. 4. The adequate absorber-skin separation was around 5cm. 5. The adequate posterior cord block width was 3cm. 6. 4:1 weighting for anterior and posterior field was adequate. And so with this technique, adequate dose distribution could be made as well as elimination junction problems.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.251-254
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• 2005

The flow forming has been used to produce long thin walled tube parts, with reduced forming load and enhanced mechanical and surface quality for a good finished part compared with other method formed parts. So flow forming technique is used widely in industrial production. Especially spinning and flow farming techniques an used frequently in automotive, aerial, defense industry. In this paper, FEM analysis of three-roller backward flow forming of a workpiece is carried out to study effects of forming depth and feed rate on forming force. The axial and radial forces on several forming depth and feed rate conditions are obtained. The phenomena such as bell mouth, build up and bulging during simulation are observed as well.

• Journal of the Korea Furniture Society
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• v.16 no.1
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• pp.27-37
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• 2005

Opening 21th Century, all the Countries of the world has been focusing on build up the foundation of cultural infrastructure in a various way, since the awareness of importance for cultural design products has been turnover. For this reason, all the countries in the world, recognize that it is more important than any other things to plan to establish a structure which is suitable to the real conditions of a region in order to efficiently manage or operate their cultural environment, in particular, they think it is urgent they should contrive to develop their regional industries with new information media, introduction and spread of the up-to-date technique of design. However, our regional related industries very difficulty for the moment for them to apply new, designing technique or to settle technical bottlenecks themselves. Accordingly, in order to resolve such a structural point at issue, this study has carried the newly designed and developed, wooden, cultural craft items that were produced by utilizing the ultramodern digital technology installed at TIDIC, it would contribute to achieve some global cultural products.