• Journal of Welding and Joining
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• v.17 no.6
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• pp.84-89
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• 1999

Most of ferrous b.c.c weld materials may experience martensitic transformation during rapid cooling after welding. It is well known that volume expansion due to the phase transformation could influence on the relaxation of welding residual stress. To apply this effect practically, it is a prerequisite to establish a numerical model which is able to estimate the effect of phase transformation on residual stress relaxation quantitatively. For this purpose, the analysis is carried out in two regions. i.e., heating and cooling, because the variation of material properties following a phase transformation in cooling is different in comparison with the case in heating, even at the same temperature. The variation of material properties following phase transformation is considered by the adjustment of specific heat and thermal expansion coefficient, and the distribution of residual stress in analysis is compared with that of experiment by previous study. consequently, in this study, simplified numerical procedures considering phase transformation, which based on a commercial finite element package was established through comparing with the experimental data of residual stress distribution by other researcher. To consider the phase transformation effect on residual stress relaxation, the transition of mechanical and thermal property such as thermal expansion coefficient and specific heat capacity was found by try and error method in this analysis.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.1
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• pp.165-176
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• 2013

This paper introduces the high density discrete wavelet transform using quincunx sampling, which is a discrete wavelet transformation that combines the high density discrete transformation and non-separable processing method, each of which has its own characteristics and advantages. The high density discrete wavelet transformation is one that expands an N point signal to M transform coefficients with M > N. The high density discrete wavelet transformation is a new set of dyadic wavelet transformation with two generators. The construction provides a higher sampling in both time and frequency. This new transform is approximately shift-invariant and has intermediate scales. In two dimensions, this transform outperforms the standard discrete wavelet transformation in terms of shift-invariant. Although the transformation utilizes more wavelets, sampling rates are high costs and some lack a dominant spatial orientation, which prevents them from being able to isolate those directions. A solution to this problem is a non separable method. The quincunx lattice is a non-separable sampling method in image processing. It treats the different directions more homogeneously than the separable two dimensional schemes. Proposed wavelet transformation can generate sub-images of multiple degrees rotated versions. Therefore, This method services good performance in image processing fields.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.3
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• pp.133-145
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• 2012

This paper describes the high density discrete wavelet transformation which is one that expands an N point signal to M transform coefficients with M > N. The double-density discrete wavelet transform is one of the high density discrete wavelet transformation. This transformation employs one scaling function and two distinct wavelets, which are designed to be offset from one another by one half. And it is nearly shift-invariant. Similarly, triple-density discrete wavelet transformation is a new set of dyadic wavelet transformation with two generators. The construction provides a higher sampling in both time and frequency. Specifically, the spectrum of the first wavelet is concentrated halfway between the spectrum of the second wavelet and the spectrum of its dilated version. In addition, the second wavelet is translated by half-integers rather than whole-integers in the frame construction. This arrangement leads to high density wavelet transformation. But this new transform is approximately shift-invariant and has intermediate scales. In two dimensions, this transform outperforms the standard and double-density discrete wavelet transformation in terms of multiple directions. Resultingly, the proposed wavelet transformation services good performance in image and video processing fields.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.241-251
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• 2021

This research explores and develops digital transformation factors influencing the logistics service-provider sector in Thailand while also examining the impact sustainability factors associated with digital transformation. Divided into two parts, Part one of the theoretical study framework covers 21 factors relating to logistics, including drivers, objectives, implications, and success factors. The second part concerns 23 factors associated with logistics sustainability, including economic, environmental, and social aspects. This quantitative empirical research was conducted using an online questionnaire instrument, and a structural equation modeling (SEM) technique was used to test the proposed model. The findings from 545 samples collected between August and November 2020 from respondents working in logistics service-provider companies in Thailand show that digital transformation drivers and objectives seem likely to impact success factors and implications in digital transformation positively. Digital transformation success factors also positively impact logistics sustainability. In comparison, logistics sustainability has a significant impact on Thailand's logistics service-provider sector's economic, environmental, and social aspects. Lastly, this research highlights the significance of digital transformation success factors and extends the current knowledge about digital transformation factors and their potential impact on logistics sustainability.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.3
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• pp.133-141
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• 2023

In the recent context of the Fourth Industrial Revolution, there is growing interest in digital transformation and smart factory as a focal point. But, the Aerospace and Defense (A&D) sector has seen limited research on digital transformation, primarily concentrating on digitally-driven areas. The study validates hypotheses pertaining to the factors that facilitate successful digital transformation within the A&D sector and the influence of digital leadership and dynamic capabilities, employing statistical tools like SPSS and AMOS. The comprehensive analysis reveals that, similar to manufacturing industries, digital leadership in A&D companies exerts an influence on successful digital transformation through dynamic capabilities. Furthermore, digital transformation within the A&D sector has a positive impact on firm performance. This paper offers empirical insights into digital transformation within the A&D sector, shedding light on how successful digital transformation can be achieved within the domestic A&D industry.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.3A
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• pp.231-239
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• 2002

This paper presents a new fractal coding scheme to find sub-optimal transformation by performing an iterative encoding process. An optimal transformation can be defined as the transformation generating the attractor which is closest to an original image. Unfortunately, it has been well-known that it is actually impossible to find the optimal transformation due to heavy computation. In this paper, however, by means of some new theorems related with the fractal transformation due the attractor, it is shown that for a special case the optimal transformation can be obtained as well as for a general case the sub-optimal transformation. The proposed method based on the theorems obtains the sub-optimal transformation performing an iterative process as if done in decoding. Thus, it requires more computation than the conventional method but improves the image quality. We verify the superiority of the proposed method through the experimental results fur real images, which shows that the proposed method approaches to the optimal method in the performance and is superior to the conventional method.

• Information Systems Review
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• v.5 no.2
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• pp.23-36
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• 2003

This study proposed the approaches to business process redesign and business network redesign in e-business environment through the case analysis of e-Transformation performed in Kolon Gloteck, Inc. which has been managed and operated in a traditional mode. The proposed e-Transformation approaches of the traditional firm in this study were as following: 1) Network-focused business process redesign; 2) Introducing ERP(Enterprise Resource Planning) as e-Business backbone; 3) Establishing transparence of business functions through using shared database; 4) Understanding customer and constructing IT(Information Technology) infrastructure for customer satisfaction; 5) Performing data and process standardization; 6) Applying the best suitable IT(Information Technology) such as JSP(Java Server Pages) and VPN(Virtual Private Network). The findings of this case study are thought to be useful as a practical guideline in carrying, out e-Transformation of the typical traditional firm and to provide significant basis for constructing the theoretical framework of e-Transformation methodology.

• Journal of Welding and Joining
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• v.28 no.3
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• pp.104-113
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• 2010

In this study, to predict the microstructure in weld HAZ of low alloyed steel, prediction model for the phase transformation considering the influence of prior austenite grain size and cooling rate was developed. For this study, six low alloyed steels were designed and the effect of alloying elements was also investigated. In order to develop the prediction model for ferrite transformation, isothermal ferrite transformation behaviors were analyzed by dilatometer system and 'Avrami equation' which was modified to consider the effect of prior austenite grain size. After that, model for ferrite phase transformation during continuous cooling was proposed based on the isothermal ferrite transformation model through applying the 'Additivity rule'. Also, start temperatures of ferrite transformation were predicted by $A_{r3}$ considering the cooling rate. CCT diagram was calculated through this model, these results were in good agreement with the experimental results. After ferrite transformation, bainite transformation was predicted using Esaka model which corresponded most closely to the experimental results among various models. The start temperatures of bainite transformation were determined using K. J. Lee model. Phase fraction of martensite was obtained according to phase fractions of ferrite and bainite.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.527-530
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• 1998

In this paper, a transformation-based English part of speech tagging system is designed and implemented. The tagging system tags raw corpus at first and the transformation rule correct the errors. Apart from traditional rule based tagging system, this system makes rules automatically. Using 60,000 words of corpus as a training corpus, the transformation rules are generated automatically by iterative training. The idea how to calculate positive effect of transformation and select transformation rules is proposed to generate more effective and correct transformations. In this paper, part of the Brown corpus and English text is used for experimental data. And the performance of transformation based tagging system is demonstrated by the calculation of accuracy.

• Journal of Plant Biotechnology
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• v.4 no.4
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• pp.135-141
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• 2002

Agrobacterium-mediated transformation has been unsuccessful for monocot plants except for a few important crops such as barley, rice, maize and wheat. We discussed here that a successful transformation of monocots demands certain critical conditions. The requirements for an efficient transformation are a selection of target tissues competent for plant regeneration and Agrobacterium-infection, and various factors promoting Agrobacterium-infection. The factors were divided into two to activate Agrobacterium and to increase plant cell's susceptibility against Agrobacterium. Optimization of these factors significantly increased transformation efficiency of zoysia grass and rice plants. A technical improvement in transformation system for monocots will promote improvement of the breed as well as a study of gene functions in monocots.