• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.3-7
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• 2005

A lighting method of our county is ordinary center concentration form. Therefore, it is usally used the Five Point Method, Multiplicity Method of KS, and Four Point Method of IES to measure a space illuminance. We can use the Five Point Method of KS when we measure a uniformity ratio or activities that happen in space is more sensitive than whole illumination. In addition, we can use the Multiplicity Method of KS and Four Point Method of IES when we measure whole illuminance like mean illuminance. Such method of measurements should be used exactly according to the kinds of space and activities.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.4
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• pp.33-39
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• 2014

To establish the reliability of a packaging structures, adhesion testing of key interfaces is a critical task. Due to the material mismatch, the interface may be prone to delamination failure due to conditions during the manufacturing of the product or just from the day-to-day use. To assess the reliability of the interface adhesion strength testing can be performed during the design phase of the product. One test method of interest is the four-point bending (4PB) adhesion strength test method. This test method has been implemented in a variety of situations to evaluate the adhesion strength of interfaces in bimaterial structures to the interfaces within thin film multilayer stacks. This article presents a review of the 4PB adhesion strength testing method and key implementations of the technique in regards to semiconductor packaging.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.325-330
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• 2015

With approval from the Asia Pacific Metrology Program Working Group on Materials Metrology (APMP WGMM), an international comparison for sheet resistance standards for silicon wafers was firstly conducted among Korea Research Institute of Standards and Science (KRISS) in Korea, CMS/ITRI in Taiwan, and NIM in China, which are national metrology institutes (NMIs), from August 2011 to January 2012. The sheet resistance values of the standards are $10{\Omega}$, $100{\Omega}$, and $1000{\Omega}$; the measurement was conducted in sequence at KRISS, CMS/ITRI, NIM, and KRISS again using the four-point probe method with single and dual configuration techniques. The reference value for the measurement results of the three NMIs was obtained through averaging the values of the three results for each sheet resistance range. The differences between the reference value and the measured values is within 0.22% for $10{\Omega}$, 0.17% for $100{\Omega}$, and 0.12% for $1000{\Omega}$. Therefore, the international consistency for conducting sheet resistance measurements is confirmed within 0.22% through the APMP WGMM approved comparison.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1314-1319
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• 2017

A handheld sheet resistance meter that can easily and quickly measure the sheet resistance of indium tin oxide films was developed. The dual-configuration four-point probe method was adopted for this instrument, which measured sheet resistance in the range from $0.26{\Omega}/sq$. to $2.6k{\Omega}/sq$. with 0.3 % ~ 0.5 % uncertainty. The screen of the instrument displayed the sheet resistance when the probe was in contact with the sample surface and the value continued to be displayed during the probe contact. Even after separating the probe from the surface, the value was still displayed on the screen and could be read easily. A feature of the instrument was the use of the dual-configuration technique to reduce edge effects markedly compared with the single-configuration technique and its ease of operation without applying correction factors for sample size and thickness.

• Water for future
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• v.15 no.4
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• pp.39-44
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• 1982

A numerical computation of unsteady flow in the open channel was studied with the linearized four-point method of characteristics. A seiche test for this model was fulfilled and its result was very close to the exact solution. The effect of linearization to the accuracy of the result was small enough for the analysis of nearly horizontal flow, and this model would be applicable for the real unsteady flow problem because of its convenience.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.576-584
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• 2009

Up to now, it has been said that no satisfactory computer solution has been found for synthesizing four-bar linkage based on the prescribed coupler link curve. In our study, an algorithm has been developed to improve the design synthesis of four bar linkage based on the 5 precision points method. The suggested algorithm generates the desired coupler curve by using NURBS, and then the generated curve approximates as closely as possible to the desired curve representing coupler link trajectory. Also, when comparing each generated curve by constructing the control polygon, rapid comparison is easily achieved by applying convex hull of the control polygon. Finally, an optimization process using ADS is incorporated into the algorithm based on the 5 precision point method to reduce the total optimization process time. As for examples, two four bar linkages were tested and the result well demonstrated the effectiveness of the algorithm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.4 s.175
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• pp.874-880
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• 2000

In this paper, a DC potential drop measurement system was used to find the position of the flaw on a simple thin plate. Four-point probe test was evaluated and used for this study. In the four-point probe test, the more distance between current pins provides the more measurable scope, the less voltage difference, and the more voltage difference rate. In the other hand, the more distance between voltage pins provides the less voltage difference and the less voltage difference rate. An optimized four-point probe was applied to measure the relation between voltage and the relative position of flaw to the probe. The Maxwell 21) simulator was used to analyze the electromagnetic field, and it showed that the analytical result was similar to the experimental result within 11.4% maximum error.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.173-174
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• 2008

The four-point bending test is a widely used method to determine material parameters. The aim of the present study was to evaluate the flexural strength (or modulus of rupture) and the Weibull modulus of cordierite ceramic substrate by means of four-point bending tests. The strength data from experiments followed Weibull statistics. These data indicate that the fatigue effects are more severe when the substrate temperature in the peripheral region is near $200^{\circ}$. At temperatures well above $200^{\circ}C$ the available design strength can be as high as 65% as substrate's initial strength.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.688-693
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• 2002

Adhesive bonding is becoming one of the popular joining techniques in metal industries, since it has some advantages over other techniques such as welding and diffusion bonding, e.g., any dissimilar metals are easily adhesive-bonded together. In this study, the experiments were carried out in order to provide the statistical data with strength evaluation methods: tension, shear and four-point bending tests for thermoplastic epoxy resin based adhesive-bonded metal joints. We should certificate on the probability of the adhesive strength that has the tendency of brittle fracture, the adhesive bonding strength between metals with thermoplastic adhesive has the best probability at four-point bending test. The strength testing method that has higher probability is four-point bending test, shear test and tensile test in order.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.10
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• pp.126-131
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• 1999

Up until now, it is said that no satisfactory computer solutions have been found for synthesizing four-bar linkage based on the prescribed coupler link curve. In our study, an algorithm has been developed to improve the design synthesis of four-bar linkage automatically generating prescribed path by using B-spline interpolation. The suggested algorithm generates the desired coupler curve by using B-spline interpolation, and hence the generated curve approximates as closely as to the desired curve representing coupler link trajectory. Also, when comparing each generated polygon with the control polygon, rapid comparison by applying convex hull concept. finally, optimization process using ADS is incorporated into the algorithm based on the 5 precision point method to reduce the total optimization process time. As for examples, three different four-bar linkages were tested and the results showed the effectiveness of the algorithm.