• The Journal of Advanced Prosthodontics
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• 제6권3호
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• pp.224-232
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• 2014

PURPOSE. The purpose of the present study was to evaluate the effect of thermocycling and mechanical loading on the biaxial flexural strength and the phase transformation of one Ce-TZP/$Al_2O_3$ and two Y-TZP core materials. MATERIALS AND METHODS. Thirty disc-shaped specimens were obtained from each material. The specimens were randomly divided into three groups (control, thermocycled, and mechanically loaded). Thermocycling was subjected in distilled water for 10000 cycles. Mechanical loading was subjected with 200 N loads at a frequency of 2 Hz for 100000 times. The mean biaxial flexural strength and phase transformation of the specimens were tested. The Weibull modulus, characteristic strength, 10%, 5% and 1% probabilities of failure were calculated using the biaxial flexural strength data. RESULTS. The characteristic strengths of Ce-TZP/$Al_2O_3$ specimens were significantly higher in all groups compared with the other tested materials (P<.001). Statistical results of X-ray diffraction showed that thermocycling and mechanical loading did not affect the monoclinic phase content of the materials. According to Raman spectroscopy results, at the same point and the same material, mechanical loading significantly affected the phase fraction of all materials (P<.05). CONCLUSION. It was concluded that thermocycling and mechanical loading did not show negative effect on the mean biaxial strength of the tested materials.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.79-84
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• 2004

Strain energy due to the mechanical interaction between self-accommodation groups of martensitic phase transformation is called interaction energy. Evaluation of the interaction energy should be accurate since the energy appears in constitutive models for predicting the mechanical behavior of shape memory alloy. In this paper, the interaction energy is evaluated in terms of theoretical formulation and explicit finite element calculation. A simple example with two habit plane variants was considered. It was shown that the theoretical formulation assuming elastic interaction between the self-accommodation group and matrix gives larger interaction energy than explicit finite element calculation in which transformation softening is accounted for.

• 한국수산과학회지
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• 제50권2호
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• pp.195-206
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• 2017

Joint time-frequency images of the broadband echo signals of six fish species were obtained using the smoothed pseudo-Wigner-Ville distribution in controlled environments. Affine transformation and principal component analysis were used to obtain eigenimages that provided species-specific acoustic features for each of the six fish species. The echo images of an unknown fish species, acquired in real time and in a fully automated fashion, were identified by finding the smallest Euclidean or Mahalanobis distance between each combination of weight matrices of the test image of the fish species to be identified and of the eigenimage classes of each of six fish species in the training set. The experimental results showed that the Mahalanobis classifier performed better than the Euclidean classifier in identifying both single- and mixed-species groups of all species assessed.

• 공학교육연구
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• 제14권5호
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• pp.67-74
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• 2011

The object of this study is to examine the process of the birth and transformation of civil engineering education as well as of modern civil engineers, called 'State noblesse', in the state engineer groups of France. For this, we will look into the background of founding the civil engineer corps and the civil engineering school, the transformation process of the civil engineering school into the applied school of Ecole Polytechnique, the activities of civil engineers in the industrialization process, and finally the organization and identity of the civil engineer group.

• 한국방사선학회논문지
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• 제13권4호
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• pp.509-516
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• 2019

전산화단층촬영에서 선형 및 비선형변환방법을 이용하여 탐색밀도에 따른 압축률과 최대신호대 잡음비를 구하여 의료영상 압축의 화질에 대하여 알고자 한다. 선형변환방법은 원 영상을 여러 개의 레인지블록으로 나눈 후 각각의 레인지블록에 대하여 영상내의 존재하는 최적의 도메인블록을 찾는 부분변환시스템을 사용하여 닮은 블록을 찾아서 압축율과 화질의 성능을 조정가능 하므로 비선형변환방법은 8개의 셔플변환 중에서 회전변환만을 이용하는데, 한정된 도메인블록에서만 탐색이 이루어지므로 영상내의 임의의 블록에 대하여 도메인블록을 탐색하는 선형변환방법보다는 부호화 시간이 빠르나 실제 영상에서 레인지블록에 대한 최적의 도메인블록을 선택할 수 없기 때문에 성능은 다른 방법에서 보다 떨어질 수 있어서 비선형변환방법은 최적의 도메인블록을 선택하는 대신 밝기계수 변환의 근사화 정도를 높여서 성능을 개선하고, 블록의 크기가 작을수록 최대신호대 잡음비(PSNR;peak signal to noise ratio)값은 높아지며 블록의 크기가 클수록 압축비가 높아지므로 최적으로 영상을 부호화하기 위해 퀴드트리 블록분할을 하였다.

• Mycobiology
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• 제47권1호
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• pp.59-65
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• 2019

Agrobacterium tumefaciens-mediated transformation (ATMT), as a simple and versatile method, achieves successful transformation in the yeast-like cells (YLCs) of Tremella fuciformis with lower efficiency. Establishment of a more efficient transformation system of YLCs is important for functional genomics research and biotechnological application. In this study, an enzymolysis-assisted ATMT method was developed. The degradation degree of YLCs depends on the concentration and digestion time of Lywallzyme. Lower concentration (${\leq}0.1%$) of Lywallzyme was capable of formation of limited wounds on the surface of YLCs and has less influence on their growth. In addition, there is no significant difference of YLCs growth among groups treated with 0.1% Lywallzyme for different time. The binary vector pGEH under the control of T. fuciformis glyceraldehyde-3-phosphate dehydrogenase gene (gpd) promoter was utilized to transform the enzymolytic wounded YLCs with different concentrations and digestion time. The results of PCR, Southern blot, quantitative real-time PCR (qRT-PCR) and fluorescence microscopy revealed that the T-DNA was integrated into the YLCs genome, suggesting an efficient enzymolysis-assisted ATMT method of YLCs was established. The highest transformation frequency reached 1200 transformants per $10^6$ YLCs by 0.05% (w/v) Lywallzyme digestion for 15 min, and the transformants were genetically stable. Compared with the mechanical wounding methods, enzymolytic wounding is thought to be a tender, safer and more effective method.

• 대한금속재료학회지
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• 제49권1호
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• pp.46-51
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• 2011

Real-time formation of $L1_0$ phase of FePt nanoparticles in the gas phase during ultrasonic-spray pyrolysis is first discussed in the present study. Without any post heat treatment, $L1_0$ phase of FePt nanoparticles appeared at the temperature above $900^{\circ}C$ in the gas phase synthesis. X-ray diffractometry (XRD) and transmission electron microscopy (TEM) studies revealed that FePt nanoparticles less than 10 nm in size contained small volume of $L1_0$ fct phase. However, in other samples obtained at the temperature below $900^{\circ}C$, iron oxide phase co-existed and no evidence of phase transformation was found. Thus, it is anticipated that the time of flight of particles required for crystallization and phase transformation was extended according to the increase of the collision rate. Finally, magnetic properties represented by coercivity and saturation magnetization and functional groups on the particle surface were discussed based on VSM and FT-IR results.

• 아태비즈니스연구
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• 제14권3호
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• pp.1-16
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• 2023

Purpose Despite the ongoing digital transformation, it is not clear whether emerging market firms follow their manufacturing FDI path in the emerging digital industries. This paper examines how digital orientation affects the location strategies in internationalization and how the existing innovation capacities moderate the link between digital orientation and the location strategies. Design/methodology/approach This study chooses the Chinese setting for research design because digital transformation is already prevalent in the society and the cases of outward expansion are salient among the emerging markets. It uses the panel dataset of 976 Chinese listed firms that consists of 6,648 observations spanning from 2007 to 2017. Ordinary least square regression is used for the statistical approach with a one-year lag in the model. Findings Digital orientation increases a likelihood of emerging multinationals' entries in developed countries, and a high level of innovative capacities strengthens the link. Two groups seem to prefer entries in developed countries: firms with a high level of digital orientation with a high level of innovative capacities and firms with a low level of digital orientation, if with a low level of innovative capacities. The former reflects the context of digital transformation and the latter hints at the tax avoidance or interests in real estate. Research implications or originality While emerging multinationals are known to prefer entries in developing countries for capacity arbitrage, our results forecast that their FDI strategies may have a drastic change as digital transformation deepens.

• 대한미생물학회지
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• 제18권1호
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• pp.59-65
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• 1983

To investigate the effects of placental serum to in vitro culture of the normal human lymphocytes the peripheral blood lymphocytes were isolated by ficoll-hypaque separation method in 20 healthy human adults. The blast transformation respone of lymphocytes to mitogens were observed by stimulation with PHA($25{\mu}g/ml$) and Con A($25{\mu}g/ml$) using RPMI 1640 media containing 20% placental serum(PS), tetal calf serum(FCS), or humans AB serum(AB). And one-way mixed lymphocyte culture test was performed between these unrelated person compounded into stimulators and responders to investigate the effect of placental serum. The following results were obtained. 1. In 20 experimental cases, these were no significant diffenence between FCS, AB, and PS in untreated control cultures. 2. In PHA-treated cultures, whereas the blast transformation rate of the FCS groups and AB groups were $40.8{\pm}4.3%$ and $44.6{\pm}4.3%$ respectively, that of PS groups were $21.7{\pm}3.4%$, Similar results were obtained in Con A-meated cultures. Therefore, placental serum inhibited the mitogenic response of lymphocytes significantly. 3. In MLC tests, stimulation index of the FCS groups and AB groups were $18.5{\pm}3.5$ and $20.1{\pm}3.3$ respectively. But placental serum inhibited MLC response of lymphocytes significantly($7.4{\pm}1.9$).

• 산업경영시스템학회지
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• 제40권4호
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• pp.67-77
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• 2017

With the advent of the fourth industrial revolution, the digital transformation craze has intensified in diverse industries, such as finance, automotive, health care and agriculture. However, relative to industry demand, there is only few domestic research on digital transformation of small traders and no one has implemented empirical study on this field at all. Thus, the study conducted an empirical study to measure the digital transformation intention of domestic small traders. In the early days of domestic business start-ups, we searched for factors affecting the digital conversion intention of small business owners and designed an integrated framework to explain the causal relationship between factors. This study not only expanded and refined the scope of related research but also suggested the direction of another research that was not presented in previous research. However, there are limitations in many ways as much as the initial stage of a specific field of small business owners. There are limitations in explaining the overall perception of Korean small business owners. Therefore, in future studies, it is necessary to study more deeply by presenting more specific and various variables. In addition, although the number of respondents was sufficient in the process of empirical analysis, it is considered that the respondents are not enough to universalize the research result as a traditional small business person who did not convert all digital. It is necessary to carry out a comparative analysis by dividing the two groups in more detail and more specifically in the future study. The result of this study can suggest the direction for accelerating small traders' digital transformation intention in terms of practical view, and provide useful references which can support the theoretical foundation for researchers who will perform future related research in terms of academic view.