• Journal of the Chungcheong Mathematical Society
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• v.24 no.4
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• pp.825-832
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• 2011

In this paper, we make a minute and detailed proof of a part which is omitted in the process of obtaining the value of the curvature tensor for an invariant affine connection at the point {H} of a reductive homogeneous space G/H in the paper 'Invariant affine connections on homogeneous spaces' by K. Nomizu.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.3
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• pp.529-536
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• 2001

We investigate a surface-micromachined capacitive accelerometer with the grid-type electrodes surrounded by a perforated proof-mass frame. An electromechanical analysis of the microaccelerometer has been performed to obtain analytical formulae for natural frequency and output sensitivity response estimation. A set of prototype devices has been designed and fabricated based on a 4-mask surface-micromachining process. The resonant frequency of 5.8$\pm$0.17kHz and the detection sensitivity of 0.28$\pm$0.03mV/g have been measured from the fabricated devices. The parasitic capacitance of the detection circuit with a charge amplifier has been measured as 3.34$\pm$1.16pF. From the uncertainty analysis, we find that the major uncertainty in the natural frequency of the accelerometer comes from the micromachining error in the beam width patterning process. The major source of the sensitivity uncertainty includes uncertainty of the parasitic capacitance, the inter-electrode gap and the resonant frequency, contributing to the overall sensitivity uncertainty in the portions of 75%, 14% and 11%, respectively.

• Journal of the Korean Operations Research and Management Science Society
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• v.27 no.4
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• pp.185-205
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• 2002

In this study, we consider infinite supply of raw materials and backlogged demands as given two boundary conditions. And we need not make any specific assumptions about the inter-arrival of external demand and service time distributions. Under these situations, the ultimate objective of this study is to prove the variability propagation principle in a pull serial line and is to measure it in terms of the first two moments of the inter-departure process subject to number of cards in each cell. Two preparations are required to achieve this objective : The one is to derive a true lower bound of variance of the inter-departure process. The other is to establish a constrained discrete minimax problem for the no backorder (backlogging) probabilities in each cell. We may get some fundamental results necessary to a completion for the proof through the necessary and sufficient conditions for existence of optimal solution of a constrained discrete minimax problem and the implicit function theorem. finally, we propose a numeric model to measure the variability propagation principle. Numeric examples show the validity and applicability of our study.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.67-75
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• 2021

As pass the three revised bills, the Personal Information Protection Act was revised to have a larger application for personal information. For an industrial development through an efficient and secure usage of personal information, there is a need to revise the existing anonymity processing method. This paper modifies the Zero Knowledge Proofs algorithm among the anonymity processing methods to modify the anonymity process calculations by taking into account the reliability of the used service company. More detail, the formula of ZKP (Zero Knowledge Proof) used by ZK-SNAKE is used to modify the personal information for pseudonymization processing. The core function of the proposed algorithm is the addition of user variables and adjustment of the difficulty level according to the reliability of the data user organization and the scope of use. Through Setup_p, the additional variable γ can be selectively applied according to the reliability of the user institution, and the degree of agreement of Witness is adjusted according to the reliability of the institution entered through Prove_p. The difficulty of the verification process is adjusted by considering the reliability of the institution entered through Verify_p. SimProve, a simulator, also refers to the scope of use and the reliability of the input authority. With this suggestion, it is possible to increase reliability and security of anonymity processing and distribution of personal information.

• Journal of the Korean Graphic Arts Communication Society
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• v.20 no.1
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• pp.79-90
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• 2002

Recently, the research about color matching for the input/output devices of printing process is progressing rapidly by the digitization. The calibration method of flatbed scanner widely used as an input device for prepress process is especially important for color proofing of high quality color prints. In this paper, scanner calibration method using 3-dimensional look-up table and tetrahedral interpolation was examined and analysed comparatively on the three kinds of original copies, such as photograph, dye sublimation proof and ink jet print for IT8.T/2 target.

• Journal of the Korean Statistical Society
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• v.36 no.4
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• pp.471-477
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• 2007

In this paper, we provide a new proof to correct the asymptotic normality for the estimate $\hat{C}_{pmk}\;of\;C_{pmk}$, which is one of the well-known definitions of the process capability index. Also we comment briefly on the correction of the limiting distribution for $\hat{C}_{pmk}$ and on the use of re-sampling methods for the inference of $C_{pmk}$. Finally we discuss the concept of asymptotic unbiasedness.

• The Mathematical Education
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• v.41 no.2
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• pp.215-225
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• 2002

In this paper we consider some properties of. bisector of interior angle(theorem 1) and exterior angle(theorem 2) in triangle by using analogy. As a result of analyzing various mathematics textbooks we have known that they focused not on relation between two theorems, but on describing two theorems. We have seen that theorem 2 is able to be inferred from theorem 1 by using analogy. After proving theorem 1 by some methods we analyze proof process, extract proof ideas, and analogize some ideas for proving theorem 2. From this we are able to find relationships between theorem 1 and 2.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.777-781
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• 1997

One of the spring-link mechanisms, the air circuit breaker(ACB), was studied to improve the shock-proof characteristics of it. The low-cycle fatigue fracture phenomenon was occurred on the critical link, called h-link, of ACB for the repeated rapid closing and opening operations. To analyze the cause of failure, dynamic FE-analysis on the h-link part of ACB was accomplished with considered the velocity and acceleration of the links per time as boundary conditions, which were obtained by using ADAMS. Then, to reduce the maximum tensile stress on the h-link, three types of h-link were suggested and one of them was selected. Fmm this study, we suggested the process of analysis on the high-speed motion behavior part related low-cycle fatigue fractures.

• Journal of Fashion Business
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• v.15 no.6
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• pp.101-112
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• 2011

Three-dimensional(3D) virtual clothing simulation system may require the use of physical, mechanical, and configurational data in order to mimic the actual clothing with high degree of realism. Therefore the 3-dimensional scanning system based on optical methods was adopted to extract the 3-dimensional data of the fabric surface. In this study, the appearances of the 3-dimensionally transformed textile fabrics via several finishing procedures were investigated using a 3D scanning system. The wool gauze fabrics treated with the shrink-proof finishing and the felting process showed height changes up to 4.5mm. The 3-dimensional configuration may be objectively described by the use of mesh generation from the scanned output. The generated mesh information may further be utilized in the 3D virtual clothing simulation system for accurate description of the fashionable textile materials used in the simulation system.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.589-594
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• 2002

In manufacturing of welded parts which require a proof on acceptance close observation of the process is mandatory. The manufacturer is obliged to document the welding process. An approach for monitoring and recording the process of laser beam welding combining theoretical knowledge, process monitoring and welding experience will be presented. The range of application of a device for co-axial process monitoring was extended up to 20 mm sheet thickness welded in one pass at beam powers of up to 20 kW. Crucial features of the process which refer to the formation of failures were observed. The results presented give rise to the general applicability of the approach for process monitoring and recording as well as failure management.