• Journal of Welding and Joining
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• v.22 no.1
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• pp.65-70
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• 2004

A soldering process with longitudinal ultrasonic is conducted in this work using the Au bump and substrate. Localized heating of the solder is achieved and the stirring action due to the ultrasonic is found to influence the bond strength and microstructure of the eutectic solder The acceptable bonding condition is determined from the tensile strength. Since the multiple bonds can be formed simultaneously with localized heating, the proposed ultrasonic soldering method appears to be applicable to the high-density electronic package.

• Journal of the Korean institute of surface engineering
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• v.54 no.3
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• pp.158-163
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• 2021

Some studies on electrochemical additive manufacturing of metals were summarized in this technical report, and development status of selective electrochemical 3D printing technology was introduced. In order to apply it to the PCB mass production process, essential considerations how to overcome the fundamental problems, such as the sizing, process sequence and PCB process design have been described.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.18 no.1_2
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• pp.1-8
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• 2012

Kimchi, a Korean fermented vegetable is packaged without pasteurization and distributed with live bacteria actively working to produce lactic acid and carbon dioxide gas in the product. The $CO_2$ production consisting of two distinct phases of initial fast and later slow rates depends on kimchi type, salt content and storage temperature. The $CO_2$ produced from kimchi is accumulated in the product package causing volume expansion and pressure buildup. The dependence of $CO_2$ production rate on salt content and storage temperature has been published formerly and can be used for estimating the package volume and pressure under a variety of storage conditions. As methods to alleviate the problems from the produced $CO_2$, package designs with controlled diffusion pinhole, high $CO_2$ permeable film or $CO_2$ absorber have been tried by several researchers. Properly designed packages adopting the device or tool were shown to have high dissolved $CO_2$ in kimchi without volume expansion and pressure buildup, giving good sensory quality with carbonic taste. Advantages and limitations of each method have been discussed.

• The Korean Journal of Applied Statistics
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• v.28 no.2
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• pp.343-351
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• 2015

We introduce how to fit random effects models via a SRC-Stat statistical package. This package has been developed to fit double hierarchical generalized linear models where mean and dispersion parameters for the variance of random effects and residual variance (overdispersion) can be modeled as random-effect models. The estimates of fixed effects, random effects and variances are calculated by a hierarchical likelihood method. We illustrate the use of our package with practical data-sets.

• Journal of Ecology and Environment
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• v.46 no.3
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• pp.183-189
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• 2022

Background: Radio-telemetry is a useful method to investigate the spatial ecology of species in the wild, by tracking the signal of a transmitter attached to an individual. The method of attaching a transmitter to a snake is representatively divided into surgical implantation, and external attachment, which latter is often used in small snake species. Results: In this study, we evaluated and compared the utility of two external attachment methods, the nylon thread method and the tape method, applied to a small grassland snake species of approximately 50 cm snout-vent length, the Slender racer (Orientocoluber spinalis), on an island in the Republic of Korea. The nylon thread method and the tape method were applied to four and five individuals, and radio-tracked for an average of eight and eleven days, respectively. The nylon thread method caused individual injury and disturbed their movement, while using the tape method, the transmitter package sometimes dropped off, but no injury or movement problems occurred. Conclusions: Considering that poor understanding of how to attach the transmitter makes it difficult to investigate the spatial ecology of small snake species, the tape method, evaluated in this study, could be applied to attach a transmitter and to study spatial ecology of such snakes.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.91-94
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• 2014

In this study, the laminar burning velocities of SNG fuel were studied using both experimental measurements and kinetic simulations. They were measured using the angle method of Bunsen flame configuration and the annular diverging channel combustor. And they were also numerically calculated by CHEMKIN Package with GRI 3.0 mechanisms. Spectrometer was used for characteristics of flame chemiluminescence of SNG fuels. From results of this work, first, we found that according to adding $H_2$ contents in the fuels the laminar burning velocities of SNG fuels were increased. And second, we also discovered existence of OH*, CH*, $C_2*$, HCO*, $CH_2*$ radicals and their correlation.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.244-246
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• 2008

EMTP-RV is the very powerful program to analyze the dynamic operation of the power system. To use this package in the large complex power system, it is very important to simplify the power system to simple equivalent network. In our study the 100 MVA STATCOM is placed at 345kV "MIGUM" which is the one of the 345kV substations of the Korean Electric Power System that is consist of more than 1000 bus. MIGUM substation is connected with 7 separated transmission lines to main Korean Electric power system. We developed a new method to simplify the network except the substation that we want to analysis. The power system outside the 345kV substation is modeled into the equivalent network. The loop network outside the substation can be modeled to simplified Thevenin equivalent network. The proposed method is applied to IEEE-14 Reliability Test System and the results shows the effectiveness of the method.

• Tribology and Lubricants
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• v.3 no.1
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• pp.18-25
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• 1987

The influence of one sided striated surface roughness on load carrying capacity of a slider bearing is analyzed for very low clearance films. A Reynolds equation appropriate for slider bearing is derived and analyzed by the method of finite difference method. For a slider bearing with several simple roughness form, the pressure, load capacity and other parameters can be revealed and also this results can be stored in sequential data file. After all, their distribution can be displayed easily by using the CADG(Computer Aided Design and Graphics) program. Also exact solutions with this nemerical method are compared with those of the theory attributed to Tonder and White. The results reported here should find application in the computer peripherals where computer aided design and graphic package is needed.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.190-192
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• 2006

The 3-dimensional(3D) chip stacking technology is one of the leading technologies to realize a high density and high performance system in package(SIP). It could be found that it is the advanced process of through-hole via formation with the minimum damaged on the Si-wafer. Laser ablation is very effective method to penetrate through hole on the Si-wafer because it has the advantage that formed under $100{\mu}m$ diameter through-hole via without using a mask. In this paper, we studied the optimum method for a formation of through-hole via using femto-second laser heat sources. Furthermore, the processing parameters of the specimens were several conditions such as power of output, pulse repetition rate as well as irradiation method and time. And also the through-hole via form could be investigated and analyzed by microscope and analyzer.

• Journal of the Korean Society of Costume
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• v.31
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• pp.89-99
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• 1997

In order to know what sorts of features of neck fore may be required to make plans for tight fitting collars the neck form of young japanese women were measured three deme-nsionally using. GRASP(Grating projection System for Profiling) and plaster torso. The following results were obtained: 1. We could be known the features of neck form for tight fitting collars by using both plaster torso method and GRASP method. 2. By the BASIC language in NEC computer and EXCEL package program in macin-TOSHI computer it became possible to draft a numble of neck surface automatically there-fore we got analysis of a mass of subjects.