• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.5 no.1
• /
• pp.14-19
• /
• 2009

NDE(Nondestructive examination) detects a flaw or discontinuity in materials. Flaws detected by the examination shall be evaluated for the decision basis of the integrity. The internal flaws of forging products can be detected by UT. However, UT has detection limits because of its reflected signal weakness. Normally, a 1mm or less flaw is known as the limit. If a flaw was detected, the size of flaw would be evaluated by AVG(or DGS) technique. To verify the evaluation data, alternative examination methods are needed. But there is no alternative examination methods until now. In this study, Phased array ultrasonic technique can be used to size the flaws in the generator rotor with focused beam of ultrasonic wave as a supplement method of AVG. Also, the phased array ultrasonic technique described enables the shape of flaw to be depicted exactly.

• The Journal of the Korea Contents Association
• /
• v.11 no.2
• /
• pp.13-21
• /
• 2011

It is not easy to develop the system as the subjective-type evaluation has the difficulty in natural language processing. This thesis designs and implements the automatic evaluation system with natural language processing technique. To solve the degradation of general evaluation system, we define the question type and improve the performance of evaluation through the adaptive process for each question type. To evaluate the system, we analyze the correlation between human evaluation and term-based evaluation, and between human evaluation and this system evaluation. We got the better result than term-based evaluation. It needs to expand the question type and improve the adaptive processing technique for each type.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 1998.11a
• /
• pp.172-177
• /
• 1998

For making high-functional illumination environment and pleasantness to human beings, it is needed to analyze optical characteristics from lightsource as well as to analyze and examine emotional characteristics which respond to optical characteristics systematically. Also, it is Possible to classify lightsource according to function and use based on optical and emotional characteristics systematically and these results can be applied to practical data for professional illumination design field. The aim of this study is to develop technique for evaluating sensibility as well as to accumulate sensibility database through measuring and evaluating emotional reaction to optical characteristics from lightsource. Final aim of this study is to develop simulation and evaluation technique for interior illumination environment, the outline of this paper : 1) operating simulator for various illumination environment 2) developing evaluation methodology for evaluating illumination environment 3) preparing sensibility index through evaluation and analysis The process of this study is as follows. 1) Developing optical evaluation item of lightsource 2) Developing emotional evaluation item of lightsource 3). Analyzing, correlation between optical evaluation item and emotional eveluation item 4) Classifying and selecting object for evaluation 5) Optical measuring and evaluating for lightsource 6) Operating Simulator for illumination environment 7) Emontional measuring and evaluating lightsource and color 8) Developing estimative formula and sensibility index of emotional reaction The results of this study are as follows. 1. Simulator is operated for various illumination environment, and it is proved to be applicable to actual environment. 2. Evaluation and Analysis Techniques is developed for emotional measurement about illumination environment. 3. Estimative formula and sensibility index are prepared, which can estimate the characteristic of lightsource and emotional reaction to interior color

• Journal of Ocean Engineering and Technology
• /
• v.13 no.4 s.35
• /
• pp.98-104
• /
• 1999

The crank shafts need anti-corrosion materials. So STS 304 is the essential material to manufacture this shaft. However, it costs more to manufacture the shafts by using only STS 304 than welding of STS 304 to other carbon steels. And it has been difficult to weld this sort of dissimilar materials. They could be unstable in the quality by the conventional arc welding. And also they have a lot of technical problems in manufacturing. But by the friction welding technique, it will be able to be made without such problems. Then, this study aimed not only to develop the optimization of dissimilar friction welding of crank shafts steels of STS 304, SM35C, but also to develop the application technique of the acoustic emission to accomplish in-process real-time quality(such as tensile) evaluation during friction welding of the shafts by the AE technique.

• Journal of Mechanical Science and Technology
• /
• v.19 no.3
• /
• pp.820-825
• /
• 2005

This paper proposes non-destructive ESPI technique to evaluate inside defects of semiconductor package quantitatively. Inspection system consists of ESPI system, thermal loading system and adiabatic chamber. The technique has high feasibility in non-destructive testing of semiconductor and gives solutions to the drawbacks in previous technique, time-consuming and the difficulty of quantitative evaluation. In result, most of defects are classified in delamination, from which it is inferred to the insufficiency of adhesive strength between layers and nonhomogeneous heat spread. The $90\%$ of tested samples have a delamination defect started at the around of the chip which may be related to heat spread design.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.45-48
• /
• 2005

The purpose of this study is to investigate evaluation technique of damaged depth of concrete exposed at high temperature. In order to evaluate damaged depth of core picked at member under fire, the 12 specimens have been made with variables of concrete strength(20Mpa, 40Mpa, 60Mpa). Water absorption after heating has been measured and split tensile stress test was performed. The results show that the deeper of the depth from heating face, water absorption ratio is smaller and tensile failure stress is larger. Using this technique at damage evaluation of fired structure, We evaluate damaged depth of member under fire and determine the reasonable strengthening range.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.5 no.2
• /
• pp.67-76
• /
• 2010

Although both functional verification and performance evaluation are necessary for the development of effective and reliable communication systems, they have been often performed independently; by functional modeling with formal language tools and by performance modeling with professional network performance evaluation tools, respectively. Separate and repeated modeling of one system, however, would often result in cost increase and inconsistency between the models. This paper proposes an integrated model design approach in order to overcome this problem that evaluates the performance of a communication protocol designed in SDL with SDL-OPNET model conversion. The proposed technique generates OPNET skeleton code from Tau-generated C code of the SDL model by analyzing the relations between SDL and OPNET models. IEEE 802.2 LLC protocol was used as an example of model conversion to show the applicability and effectiveness of the proposed technique.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.57 no.3
• /
• pp.291-295
• /
• 2008

We have developed an evaluation technique for ratio errors of current transformer (CT) comparator by using the precise standard capacitors. By applying this technique for equivalent circuit of CT comparator evaluation system, we can obtain the calculated and measured ratio errors in the CT comparator. Thus we can evaluate ratio errors of CT comparator by comparing the calculated and measured ratio errors. Because this method requires only the standard capacitors, it is simple and easy method to reliability and accuracy maintenance of CT comparator. The method was applied to CT comparator under test with the ratio error ranges of $0{\sim}{\pm}10%$. The ratio error of the CT comparator under test theoretically obtained in this method are consistent with that measured for same CT comparator under test by using wide ratio error CT within an estimated expanded uncertainty (k = 2) in the overall ratio error ranges.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.2032-2033
• /
• 2008

We have developed an evaluation technique for phase displacement of current transformer (CT) comparator by using the precise standard capacitors and resistors. By applying this technique for equivalent circuit of CT comparator evaluation system, we can obtain the calculated and measured phase displacement in the CT comparator. Thus we can evaluate phase displacement of CT comparator by comparing the calculated and measured phase displacement. The method was applied to CT comparator under test with the phase displacement ranges of $0{\sim}{\pm}7.5$ crad. Finally we have compared the phase displacement of the CT comparator under test theoretically obtained in this method with the specification.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.57 no.4
• /
• pp.437-443
• /
• 2008

We have developed an evaluation technique for both ratio error and phase displacement of current transformer (CT) comparator by using the precise standard capacitors and resistors. By applying this technique to equivalent circuit of CT comparator evaluation system, we can obtain the calculated and measured ratio errors (or phase displacements) in the CT comparator. Thus we can evaluate ratio errors and phase displacement of CT comparator by comparing the calculated and measured ratio errors (or phase displacements). The method was applied to CT comparator under test with the ratio errors and phase displacement ranges of $0{\sim}{\pm}10%$ and $0{\sim}{\pm}7.5$ crad, respectively. Finally we have compared the ratio error and phase displacement of the CT comparator obtained in this method with specifications of two companies.