• Mass Spectrometry Letters
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• 제14권4호
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• pp.166-172
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• 2023

The utilization of methyl 2-aminobenzoate as a biocide and pesticide has raised concerns regarding its potential toxicity. To assess its safety, it is crucial to determine its quantity and related toxicity using reference materials (RMs) or certified reference materials (CRMs). As an RM and CRM containing methyl 2-aminobenzoate within a biocidal product matrix is currently unavailable, this study aimed to produce a high-quality RM containing methyl 2-aminobenzoate, ensuring its homogeneity and stability, following the ISO Guide 35 and ISO 17034. The study determined that the produced RM exhibited homogeneity, as indicated by a calculated F-value (1.91) smaller than the critical F-value (3.02). In the assessment of isochronous short-term stability, the slope of the linear regression for the RM showed no statistically significant difference from zero when stored at temperatures of 4, 18, and 60 ℃ for 4 weeks. Regarding classical long-term stability, the RM demonstrated sustained stability over the course of one year when stored at 4 ℃. This study has successfully developed an RM for monitoring methyl 2-aminobenzoate in biocides and pesticides. Its quality underwent rigorous evaluation, confirming both homogeneity and stability.

• Journal of the Korean Statistical Society
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• 제26권4호
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• pp.453-465
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• 1997

The family of power-divergence statistics conditional on margins is considered for testing homogeneity of .tau. multinomial populations with equal sample size and the exact Bahadur slope is obtained. It is shown that the likelihood ratio test conditional on margins is the most Bahadur efficient among the family of power-divergence statistics.

• 한국자기학회지
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• 제8권2호
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• pp.86-92
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• 1998

플라스틱 자석에는 균일한 자장분포와 높은 자기특성을 얻기 위해서는 균질화된 혼합물이 요구되며, 이를 위해서는 적절한 혼합경로와 혼합물의 균질도 평가방법이 필수적이다. 본 연구에서는 Sr-ferrite/EVA 플라스틱 자석에서 혼합균질도의 평가방법과 혼합균질도가 자기특성에 미치는 영향을 조사하였다. 회분식 혼합기와 단축압출기를 이용하여 균질도가 서로 다른 혼합균질도를 조사하였다. 토크센서를 이요한 혼합시 토크변화 측정방법은 임계분말충전율 결정에는 효과적인데 반해 혼합균질도 평가에는 적합하지 않았다. 이그이방성 플라스틱 자석의 분말이방화율을 이용한 균질도 평가방법은 정밀도는 높으나, 시편제조와 측정에 고가의 장비와 필요하고 자성분말 혼합물 이외에는 이용될수 없다. 모세관 레오미터를 이용한 압출압력변화 측정방법은 정밀도가 높고 측정이 간편하여 효과적이었다. 혼합물의 균질도가 증가함에 따라 분말이방화율이 증가하였으며, 분말이방화율의 증가에 따라 잔류자속밀도는 직선적으로 증가하였다.

• Journal of applied mathematics & informatics
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• 제39권5_6호
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• pp.751-760
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• 2021

We study in this paper the right Rényi mean for a quantum divergence induced from the α - z Rényi relative entropy. Many properties including homogeneity, invariance under permutation, repetition and unitary congruence transformation, and determinantal inequality have been presented. Moreover, we give the identity of two right Rényi means with respect to tensor product.

• Communications for Statistical Applications and Methods
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• 제16권2호
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• pp.389-396
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• 2009

Approximations for the null distribution of a test statistic arising in multivariate analysis to test homogeneity of variances and a mixture of two beta distributions by making use of a product of beta baseline density function and a polynomial adjustment, so called beta-polynomial density approximant, are discussed. Explicit representations of density and distribution approximants of interest in each case can easily be obtained. Beta-polynomial density approximants produce good approximation over the entire range of the test statistic and also accommodate even the bimodal distribution using an artificial example of a mixture of two beta distributions.

• Imaging Science in Dentistry
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• 제54권3호
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• pp.264-270
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• 2024

Purpose: This study aimed to propose a methodological approach for reducing the radiation dose in pediatric cone-beam computed tomography (CBCT), focusing exclusively on balancing image quality with dose optimization. Materials and Methods: The dose-area product (DAP) for exposure was reduced using copper-plate attenuation of an X-ray source. The thickness of copper (Cu) was increased from 0 to 2.2 mm, and 10 different DAP levels were used. The QUART DVT_AP phantom and pediatric radiologic dentiform were scanned under the respective DAP levels. The contrast-to-noise ratio (CNR), image homogeneity, and modulation transfer function (MTF) were analyzed using the QUART DVT_AP phantom. An expert evaluation (overall image grade, appropriateness of field of view, artifacts, noise, and resolution) was conducted using pediatric dentiform images. The critical DAP level was determined based on phantom and dentiform analysis results. Results: CNR and image homogeneity decreased as the DAP was reduced; however, there was an inflection point of image homogeneity at Cu 1.6 mm (DAP=138.00 mGy·cm²), where the value started increasing. The MTF showed constant values as the DAP decreased. The expert evaluation of overall image grades showed "no diagnostic value" for dentiform images with Cu 1.9-2.2 mm (DAP=78.00-103.33 mGy·cm²). The images with Cu 0-1.6 mm (DAP=138.00-1697.67mGy·cm²) had a "good," "moderate," or "poor but interpretable" grade. Conclusion: Reducing DAP beyond a 1.6-mm Cu thickness degraded CBCT image quality. Image homogeneity and clinical image grades indicated crucial decision points for DAP reduction in pediatric CBCT scans.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.25-28
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• 2006

This study investigated pre-mixed cement combined with ordinary portland cement, BF and SF, in order to manufacture cement binder, which is possible to produce 150MPa ultra high strength concrete. The BF used in this study reduces and control hydration heat. It can also improve concrete fluidity, while AP increases hydration product and accelerates reaction of BF. SF has micro filler effect and makes pozzolanic reaction. It also fabricates high density internal organization. This developed pre-mixed cement can reduce hydration heat and increase hydration product. It is possible to fabricate high density organization and to secure homogeneity. The mock-up test of ultra high strength concrete showed excellent dispersibility and workability and indicated compressive strength more than 150MPa at 28 days.

• 대한전자공학회논문지SP
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• 제49권4호
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• pp.120-128
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• 2012

본 논문에서는 불균일한 클러터 환경에서 다중 표적탐지 성능을 향상시키기 위한 변형된 반복 백색화 투영 통계(modified iterative pre-whitening projection statistics: MIPPS) 기법을 제안하였다. MIPPS 기법은 항공기용 레이더에서 사용하는 시공간 적응 처리(space-time adaptive processing) 알고리듬의 불균일성 검출(non-homogeneity detection: NHD) 기법으로 반사신호 세기가 서로 다른 다수의 표적이 근접거리에 혼재되어 있는 환경에서 우수한 표적탐지 성능을 나타낸다. 모의실험을 통해 기존의 다양한 NHD 기법들의 성능을 분석하고, 본 논문에서 제안하는 MIPPS 기법이 강한 표적신호에 의해 야기되는 마스킹 효과(masking effect)를 최소화하면서 반사신호 세기가 약한 표적에 대한 평균 탐지 확률을 향상시킬 수 있음을 확인하였다.

• 한국의류산업학회지
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• 제26권1호
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• pp.88-98
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• 2024

With the growing preference among Chinese consumers for purchasing beauty products through social media networks (SNS), influencer marketing has recently emerged as a crucial strategy for maximizing word-of-mouth effects. This study aims to ascertain the impact of SNS beauty influencers' characteristics on trustworthiness and consumers' intentions to engage in word-of-mouth promotion. Furthermore, the study seeks to explore the moderating role of consumer involvement in the relationship between SNS beauty influencer characteristics and the trust consumers place in them. As part of an empirical analysis, an online survey was administered to 259 Chinese female consumers who had previously purchased beauty products through influencers on SNS. The data gathered were scrutinized by conducting multiple and hierarchical regression analysis to test the proposed hypotheses. The findings indicated that the attributes of "expertise,"' "intimacy," and "homogeneity" in SNS beauty influencers significantly affect influencer trust, whereas "charm" does not have a significant impact. Moreover, consumer involvement was found to moderate the relationship between SNS beauty influencer characteristics (expertise, intimacy, charm, and homogeneity) and influencer trust. Additionally, influencer trust positively influenced the intention to engage in word-of-mouth activities. These findings signify that leveraging influencers possessing qualities such as expertise, intimacy, and homogeneity can help enhance product exposure, popularity, and sales of the beauty industry. This study contributes valuable insights into the strategic utilization of influencer characteristics in the beauty industry and digital marketing, highlighting their pivotalrole in consumer engagement and the success of marketing strategies.

• Journal of Korea Trade
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• 제24권8호
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• pp.81-100
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• 2020

Purpose - Based on complexity theory, this study develops a configurational model to predict the profitability of Halal cosmetics firms in the Indonesian and Malaysian markets. The proposed research model involves two level configurations-industry context and selling strategies-to predict high and low scores of a firm's profitability. The industry context configuration model comprises industry stability, product homogeneity, price sensitivity, and switching cost. Selling strategies include customer-focused, competitor-focused, and margin-focused approaches. Design/methodology - This is the first empirical study that calculates causal models using a combination of industry context and selling strategy factors to predict profitability. Data obtained from the marketing managers of cosmetics firms are used to test the proposed configurational model using fuzzy-set qualitative comparative analysis (fsQCA). It contributes to the current knowledge of business marketing by identifying the factors necessary to achieve profitability using analysis of condition (ANC). Findings - The results revealed that unique and distinct models explain the conditions for high and low profitability in the Indonesian and Malaysian halal cosmetic markets. While customer-focused selling strategy is necessary to attain a higher profit in both the markets, margin-focused selling strategy appears to be an essential factor only in Malaysia. Complexity of the interactions of selling strategies with industry factors and differences between across two study markets confirmed that complexity theory can support the research configurational model. The theoretical and practical implications are also illustrated. Originality/value - Despite the rapid growth of the global halal industry, there is little knowledge about the halal cosmetic market. This study contributes to the current literature of the halal market by performing a set of asymmetric analytical approaches using a complex theoretical model. It also deepens our understating of how the Korean firms can approach the Muslim consumer's needs to generate more beneficial turnover/revenue.