Deconvolution problem of cumulative distribution function with heteroscedastic errors

Thuy Le Thi Hong,Phuong Cao Xuan 한국통계학회 2023 Journal of the Korean Statistical Society Vol.52 No.2

We study the nonparametric deconvolution problem of cumulative distribution func-tion when measurement errors are heteroscedastic and have known distributions. Using a Fourier-type deconvolution method, we propose an estimator for the tar-get function that depends only on a regularization parameter. Our estimator achieves minimax optimal convergence rates when the errors are all either ordinary smooth or supersmooth. A simulation study is also conducted to illustrate the effectiveness of the proposed estimator.

The Antecedents of Online Purchase Intention of Generation Z and Millennials toward Organic Cosmetics in an Emerging Economy

Thi Thu Ha Nguyen,Hiep-Hung Pham,Ngoc Linh Dao,Hong Hanh Dao,Thi Thuy Nuong Duong,Thi Ha Chu The International Academy of Global Business and T 2023 The International Academy of Global Business and T Vol.19 No.6

Purpose - Based on the extended theory of planned behavior (TPB), this study aims to investigate the antecedents of online purchase behavior toward organic cosmetics for Generation Z (Gen Z) and Millennials by focusing on the impact of subjective norms, health consciousness, trust, attitude, and intention. Design/Methodology/Approach - A survey method using an online questionnaire was adopted to collect data from 341 Gen Z and Millennial consumers in Vietnam. The collected data were then analyzed using structural equation modeling (SEM). Findings - The results of the study showed that, among antecedents, that attitude has the strongest impact on the purchase intention of online customers toward organic cosmetics, followed by trust and subjective norms. Interestingly, health consciousness has also been found to significantly impact Gen Z and Millennial online purchase intention toward organic cosmetics. Research Implications - This paper extends the academic literature on purchase intention toward green products. More importantly, to the best of the authors’ knowledge, this study is among the first to examine the antecedents of online purchase intention toward the organic cosmetics of Gen Z and Millennials in an emerging economy, Vietnam. The findings offer important implications for cosmetics companies, retailers, and other stakeholders to have deeper insights into factors influencing young Vietnamese consumer intentions toward purchasing organic beauty products online.

Leaching of Black Dross by Hydrochloric Acid Solutions

Thi Thuy Nhi Nguyen,Thi Hong Nguyen,이만승 한국자원리싸이클링학회 2017 資源 리싸이클링 Vol.26 No.6

Leaching of black dross with HCl solution was conducted to find a suitable process to recover valauble materials. In this work, the leaching behavior of the components was compared between black dross and the residues after water treatment. All the components except TiO2 in the black dross were dissolved by HCl solution in the experimental ranges. Treatment of the black dross with water to recover the salts has negative effect on the leaching of Al2O3, MgO and SiO2. The reactions occuring during the leaching were discussed. At an optimum leaching condition of 3 M HCl and 90oC, the leaching percentage of Al2O3, MgO and SiO2 was 85, 100 and 40%, respectively.

Hydrochloric Acid Leaching Behavior of Mechanically Activated Black Dross

Thi Hong Nguyen,Thi Thuy Nhi Nguyen,이만승 한국자원리싸이클링학회 2018 資源 리싸이클링 Vol.27 No.3

Effect of ball milling treatment on the hydrochloric acid leaching performance of black dross was investigated to recover alumina. Ball milling time and speed showed limited effect on the leaching behavior of the alumina in the mechanically dross. Under the optimum mechanical activation condition (for 1h at 700 rpm), the leaching of alumina in hydrochloric acid solution was significantly affected by leaching time and reaction temperature. MgO was completely dissolved in most of the leaching conditions, while a small amount of Ca, Fe, Si and Ti oxides was dissolved. Although 80% of alumina was dissolved, the dissolved minor components such as Ca, Fe, Mg, Si and Ti oxides should be separated to recover pure alumina solution.

Phenolic Constituents from Balanophora laxiflora with their Anti-inflammatory and Cytotoxic Effects

Nguyen Thi Hong Anh,Nguyen Thuy Duong,Pham Duc Vinh,Do Thi Ha 한국생약학회 2021 Natural Product Sciences Vol.27 No.1

Balanophora laxiflora Hemsl. (Balanophoraceae) is a traditional medicinal plant with a diverse array of biological activities. In our exploration of new bioactive constituents from B. laxiflora, we isolated five compounds, including a new lignan, balanophorone (5), and four known phenolic compounds (1–4). The chemical structures of these compounds were determined by extensive spectroscopic analyses, including 1D and 2D NMR, HR-ESI-MS, and CD. In addition, we evaluated the effects of each of the isolates (1–5) on the messenger RNA expression levels of tumor necrosis factor (TNF)-α and cyclooxygenase (COX)-2 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and cytotoxicity against MCF-7 and MDA-MB-231 breast cancer cells. Compound 2 showed significant inhibition of LPS-induced COX-2 and TNF-α expression in RAW 264.7 macrophages, while compound 4 showed moderate cytotoxicity against MCF-7 and MDA-MB-231 breast cancer cells, with IC50 values of 18.3 and 30.7 μM, respectively. No significant effects on the viability of normal mammary epithelial cells were observed.

Development of a SCAR Marker Linked to Bacterial Wilt (Ralstonia solanacearum) Resistance in Tomato Line Hawaii 7996 Using Bulked-Segregant Analysis

Hai Thi Hong Truong,김수연,Hung Ngoc Tran,Thuy Thi Thu Nguyen,Long Tien Nguyen,Toan Kim Hoang 한국원예학회 2015 Horticulture, Environment, and Biotechnology Vol.56 No.4

We report the development of a codominant sequence characterized amplified region (SCAR) marker linked to resistance to a Korean R. solanacearum isolate in tomato line Hawaii 7996. Bulked segregant analysis was employed for rapid identification of RAPD markers linked to resistance genes. Genomic DNA from six resistant F9 recombinant inbred lines (RILs) and six susceptible F9 RILs, which derived from a cross between S. lycopersicum Hawaii 7996 (resistant parent) and S. pimpinellifolium WVa 700 (susceptible parent) were pooled in to an R-pool and an S-pool, respectively. A total of 800 RAPD primers were screened and only six primers (UBC#176, 205, 287, 317, 350, and 676) showed polymorphism between R- and S- pools. Of these, only two markers UBC#176 and 317 revealed a 100% linkage in the individual plants comprising the contrasting bulks. Of these, the marker UBC#176 was converted into a co-dominant SCAR marker and designated as SCU176-534. The marker SCU176-534 was confirmed by genotyping the individual of the R- and S- pools and gave the same result as UBC#176. When the marker SCU176-534 was further validated for association with resistance and its potential for maker-assisted selection (MAS) in 92 tomato lines and cultivars, the results showed that none of these carries the resistance gene. Thus, SCAR marker SCU176-534 can be used in early selection of resistant lines when Hawaii 7996 is used as a parent in a breeding program.

Determinants Influencing Entrepreneurial Intention among Undergraduates in Universities of Vietnam

BUI, Thi Hong Viet,NGUYEN, Thi Le Thuy,TRAN, Manh Dung,NGUYEN, Thi Anh Thu Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.7

The paper aims to identify the determinants that influence entrepreneurial intention among National Economics University graduates. For the sample size, we conducted a questionnaire survey of 250 full-time third-year undergraduates at the National Economics University, with convenience sampling technique. Of those 250 undergraduates, 150 were Business Administration students and 100 Economy Management students. After eliminating invalid responses due to lack of information or low quality information, 215 responses were used (93.07% of respondents) for data analysis. The results show that the factor "Perceived desirability" has the strongest impact on the intention to start a business. It is followed by the factor "Perceived feasibility" in which the "ability to search and plan for start-up" has a stronger influence on undergraduates' entrepreneurial intention than the "leadership and ability to overcome adversity". The hypothesis of a positive relationship between undergraduates' propensity to act and their intention to start a business is also supported in this study. Based on the results, we suggest some recommendations for the university and State management agencies to nurture and develop entrepreneurial intention of undergraduates, forming the young generation of potential entrepreneurs to contribute to the development of emerging countries such as Vietnam, the case study.

The Determinants of Accessibility of Financial Services in Vietnam

TRINH, Thi Thuy Hong,NGUYEN, Hoang Phong Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.3

The study aims to assess the impact of factors on the access to financial services by Vietnamese farmers. The number of respondents in this study is 402 household heads participating in six diverse agricultural value chains in Vietnam. The explanatory variables of the Multinomial Logit model estimates variables at the individual characteristics while the Mixed Logit model can combine the two types of variables together to estimate the effects simultaneously. On the other hand, the Ordinal Logit model is used to evaluate the determinants of the increase in the quantity of financial services used by individuals. The estimation results show that male-headed households have more access to financial services than females. Younger farmers are more likely to use formal financial services than the elderly. Financial literacy, land ownership, and shocks in agricultural production all have a positive impact on the probability of dealing with banks. In addition, the degree of linkage and credibility of the value chain have a significant positive impact on the accessibility of financial services to farmers. The findings of this study suggest that limiting gender inequality, focusing on youth marketing and developing agricultural value chains will have a positive impact on farmers' access to financial services.

Double burden of malnutrition in ethnic minority school-aged children living in mountainous areas of Vietnam and its association with nutritional behavior

Truong Duong Thuy Thi,Tran Trang Huyen Thi,Nguyen Tam Thanh Thi,Tran Van Hong Thi 한국영양학회 2022 Nutrition Research and Practice Vol.16 No.5

BACKGROUND/OBJECTIVES Although children of ethnic minority groups are experiencing a transition from a predominance of undernutrition to overnutrition, there is little evidence of a dual-malnutrition burden. Therefore, this study examined the double burden of malnutrition among school-aged ethnic minority children living in mountainous areas and its association with their diets. SUBJECTS/METHODS A cross-sectional study was conducted from September 2019 to March 2020 in 3 mountainous areas of Northern Vietnam among 1,556 ethnic minority school-aged children. The prevalence of under-nutrition (stunting and thinness) and over-nutrition (overweight and obesity) were measured using the WHO 2006 child growth standards (height-for-age and BMI-for-age Z-score). Nutritional practices were evaluated by the frequency of food consumption based on a 4-level scale. RESULTS The percentage of children with stunting and thinness were 14.0% and 5.4%, respectively, while the figure for overweight/obesity was 9.4%. The factors positively associated with stunting were living in a family with more than 2 children or being Muong/other ethnicities compared to the Tay ethnicity. Children who consumed fish/shrimps/crabs or milk weekly/daily were less likely to be undernourished compared to those who never consumed these foods. By contrast, children who never consumed foods rich in vitamin A precursors and vitamin A and fruit or consumed daily snacks/junk food were more likely to be overweight/obese. CONCLUSIONS Undernutrition remains a common issue among school-aged children and adolescents of ethnic minority groups, while over-nutrition exists simultaneously. Public health nutrition programs promoting adequate diets and positive lifestyle changes related to nutrition are essential to tackle the double burden of malnutrition among ethnic minority children.

Chemical constituents of the Annona glabra fruit and their cytotoxic activity.

Hien, Nguyen Thi Thu,Nhiem, Nguyen Xuan,Yen, Duong Thi Hai,Hang, Dan Thi Thuy,Tai, Bui Huu,Quang, Tran Hong,Tuan Anh, Hoang Le,Kiem, Phan Van,Minh, Chau Van,Kim, Eun-Ji,Kim, Seung Hyun,Kang, Hee Kyoun Swets Zeitlinger 2015 PHARMACEUTICAL BIOLOGY Vol.53 No.11

<P>Traditional Chinese medicines have attracted increasing interest as potential sources of novel drugs with a wide range of biological and pharmacological activities. Annona glabra Linn (Annonaceae) is used in traditional medicine as an anticancer drug. Phytochemical investigation of this plant led to the isolation of acetogenins, ent-kauranes, peptides, and alkaloids. In addition, compounds exhibited anticancer, anti-HIV-reserve, and antimalaria.</P>