Logistics Service Quality, Customer Satisfaction, and Loyalty During the COVID-19 Pandemic in Vietnam

Xuan Hung NGUYEN(Xuan Hung NGUYEN ),Thuy Dương TRAN(Thuy Dương TRAN ),Phan Hoai Diem VU(Phan Hoai Diem VU ),Yen Chi DINH(Yen Chi DINH ),Thi Mai Huong DUONG(Thi Mai Huong DUONG ),Thi Ngoc Hien THAN(Thi 한국유통과학회 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.9

The goal of the study is to examine and assess how the factors of logistics service quality provided by logistics service providers influence customer loyalty and satisfaction in Vietnam. This study employs samples of the Kansei technique. The article’s data was gathered through an online survey of 388 distinct Vietnamese customers who used logistics services before and during the Covid-19 outbreak. After the data was obtained, it was evaluated using SmartPLS 3.0’s Cronbach’s Alpha test and structural equation model (SEM). Staff service quality, operational service quality, and technical service quality are the three factors that determine the quality of logistics services in the study. Out of the 10 proposed hypotheses, research findings show that five are acceptable. The Covid-19 Pandemic in Vietnam had a significant impact on all dimensions, but it had no effect on how satisfied customers were with the logistics service providers. Nevertheless, loyalty is considerably influenced by only one factor, which is customer satisfaction, and customer trust moderates the relationship between these two factors. As a consequence of that, several managerial implications have been proposed to help logistics service providers improve their services to attract and keep Vietnamese customers using their service in the long term.

Dynamic analysis and improvement of the sinking performance of the Vietnamese tuna purse seine using numerical methods

HUNG, Dinh Xuan,LEE, Chun Woo,PARK, Subong The Korean Society of Fisheries and Ocean Technolo 2016 수산해양기술연구 Vol.52 No.1

In this study, numerical method was used to assess technical properties and improve the Vietnamese tuna purse seine. The data were extracted from the two national level projects. The study results showed that average lead-line sinking speed reached 0.139 m/s and 0.143 m/s and maximum sinking depth was 61.6 m and 65.8 m for The gears 2003 and 2014 respectively. The maximum tension on ring line of The gear 2003 was 4,742 kgf and 2014 was 4,219 kgf. The improved tuna purse seines I, III and IV showed similar sinking speed results with 0.220 m/s, 0.219 m/s and 0.219 m/s respectively. The average lead-line sinking speed of the improved gear II was lowest with 0.215 m/s. The maximum lead-line sinking depth of the four improved gears I, II, III and IV were 116 m, 112 m, 115 m and 114.9 m respectively. Maximum tension on ring line of the improved gears I, II, III and IV were 5,657 kgf, 5,406 kgf, 5,645 kgf and 5,654 kgf respectively. The improved tuna purse seine IV is the most suitable for Vietnamese tuna purse seine fishery, Which corresponds with tuna purse seiner scale and its fishing supporting equipment at the present.

Sensitive Colorimetric Detection of Prostate Specific Antigen Using a Peroxidase-Mimicking Anti-PSA Antibody Coated Au Nanoparticle

Xuan-Hung Pham,함은일,Kim-Hung Huynh,Byung Sung Son,김형모,전봉현 한국바이오칩학회 2020 BioChip Journal Vol.14 No.2

The use of colorimetric bioassays for protein detection is one of the most promising diagnostic approaches, but their relatively poor detection limits have been a critical issue. In this study, we developed an efficient colorimetric bioassay based on antibody-coated peroxidase-mimicking Au nanoparticles (Au NPs) for the detection of prostate-specific antigen (PSA), which is one of the most widely used protein biomarkers for the diagnosis of prostate and breast cancers. Anti-PSA antibody adsorption on the Au NP surface result in 65% of the peroxidasemimicking properties of Au NPs was suppressed to maximize sensitivity of the assay. Anti-PSA antibody adsorption on the Au NP was optimized at 150 µg/mL anti-PSA4 antibody for 1 h incubation, and their surface was blocked with 2% BSA. The experimental conditions of the immunoassay detection were also investigated. A highest assay value was obtained at 10 µg/mL anti-PSA1 capture antibody using 3% BSA for surface blocking and at 2.5 pM anti- PSA4-Ab coated Au NPs for 1 h incubation with PSA antigen. As a result, PSA was detected at a wide range of 0.25 to 2,500 ng/mL with a detection limit of 0.23 ng/mL. The anti-PSA-Ab coated Au NP- based assay was simple, easy to operate, and sensitive. The proposed peroxidase-mimicking anti-PSA Ab-coated Au NPbased assay could be further developed to detect other protein biomarkers.

Photovoltaic Hot Spot Detection Method Integrated into a Boost Converter

Xuan Hung Mai(매준훙),Katherine A. Kim(김예린) 전력전자학회 2015 전력전자학술대회 논문집 Vol.2015 No.07

Comprehensive Electric-Thermal Photovoltaic Modeling for Power-Hardware-in-the-Loop Simulation (PHILS) Applications

Xuan Hung Mai,Sang-Kyu Kwak,Jee-Hoon Jung,Kim, Katherine A. Institute of Electrical and Electronics Engineers 2017 IEEE transactions on industrial electronics Vol.64 No.8

<P>This paper presents a dynamic, electricthermal model for a photovoltaic (PV) cell that combines electrical and thermal parameters to accurately emulate PV panels in real time for power-hardware-in-the-loop simulation (PHILS). In this model, the irradiance and ambient temperature are used to calculate the PV cell temperature based on a five-layer thermal model. The cell temperature is then used in the electrical model to accurately adjust the PV electrical characteristics. A custom experimental setup is built to test and verify the electrical and thermal characteristics of the PV cell model. This electric-thermal model is validated using experimental data in realistic scenarios. The model is also tested with PHILS using a real-time simulator and a programmable dc power supply to emulate PV power generation under various load changes. The model is well matched to the experimental measurements with an error within 2.4% for the electrical aspects and within 1.5% for the thermal aspects in the tested scenarios.</P>

Metabolism of dl-Praeruptorin A in Rat Liver Microsomes using HPLC-Electrospray Ionization Tandem Mass Spectrometry

Hang Ruan,Xuan Zhu,Zhen Zhang,Xin-fang Liang,Yan Fu,Mei-qin Su,Qi-lin Liu,Xiu-min Wang 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.8

dl-Praeruptorin A (Pd-Ia) is the major active constituent of the traditional Chinese medicine Peucedanum praeruptorum Dunn. Recently it has been identified as a novel agent in the treatment and prevention of cardiovascular diseases. Accordingly, we investigated the metabolism of Pd-Ia in rat liver microsomes. The involvement of cytochrome P450 (CYP) and CYP isoforms were identified using a CYP-specific inhibitor (SKF-525A), CYP-selective inhibitors (α-naphthoflavone, metyrapone, fluvastatin, quinidine, disulfiram, ketoconazole and ticlopidine) and CYP-selective inducers (phenobarbital, dexamethasone and β-naphthoflavone). Residual concentrations of the substrate and metabolites were determined by HPLC, and further identified by their mass spectra and chromatographic behavior. These experiments showed that CYP450 is involved in Pd-Ia metabolism, and that the major CYP isoform responsible is CYP3A1/2, which acts in a concentration-dependent manner. Four Pd-Ia metabolites (M1, M2, M3, and M4) were detected after incubation with rat liver microsomes. Hydroxylation was the primary metabolic pathway of Pd-Ia, and possible chemical structures of the metabolites were identified. Further research is now needed to link the metabolism of Pd-Ia to its drug-drug interactions.

Multi-scale object-based fuzzy classification for LULC mapping from optical satellite images

Hang T. Do,Venkatesh Raghavan,Luan Xuan Truong,Go Yonezawa 대한공간정보학회 2019 Spatial Information Research Vol.27 No.2

In this paper, a multi-scale object-based fuzzy approach is demonstrated for land use/land cover (LULC) classification using high-resolution multi-spectral optical RapidEye and IKONOS images of Lao Cai and Can Tho areas in Vietnam respectively. Optimal threshold for segmentation procedure is selected from rate of change-local variance graph. Object-based fuzzy approach is implemented to identify LULC classes and LULC initial sets, and then the initial sets are classified to final LULC classes. In case of Lao Cai area, normalized difference vegetation index (NDVI), normalized difference water index (NDWI), water index (WI) in object-based are used to generated water, terrace field classes, and built-up and vegetation sets. NDVI, soil index (SI) and red band are used to distinguish built-up set to building, bare land and road classes. NDVI and RedEgde band are inputs to classify rice field and forest classes from vegetation set. In case of Can Tho area, NDWI and WI are generated to water, vegetation, paddy field classes and built-up set, and then built-up set is classified to building, bare land, road, and paddy field classes. The technique is able to create LULC maps of Lao Cai and Can Tho areas with (90.8%, 0.84), and (92.3%, 0.90) classification accuracy and kappa coefficient, correspondingly.

Photo induced NO₂ sensing properties of bismuth triiodide (BiI₃) nanoplates at room temperature

Hung, Pham Tien,Hien, Vu Xuan,Hoat, Phung Dinh,Lee, Sangwook,Lee, Joon-Hyung,Kim, Jeong-Joo,Heo, Young-Woo Elsevier 2019 Scripta materialia Vol.172 No.-

<P><B>Abstract</B></P> <P>Herein we report on the growth of layered BiI<SUB>3</SUB> nanoplates materials and their sensing properties of NO<SUB>2</SUB> under violet light illumination. The BiI<SUB>3</SUB> nanoplates were grown on a glass substrate using a chemical vapor deposition (CVD) system, with an average thickness of 30 nm and the lateral dimension of 150–170 nm. Their photo-induced sensing response for 20 ppm NO<SUB>2</SUB> and the response/recovery time are approximately ~11.2% and 18/36 s, respectively. The limit of detection (LOD) of NO<SUB>2</SUB> for the BiI<SUB>3</SUB> sensor is 25 ppb. A possible light-induced gas-sensing mechanism was proposed and investigated for the BiI<SUB>3</SUB> nanoplate.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Experimental investigation of the vertical pullout cyclic response of bucket foundations in sand

Hung, Le Chi,Lee, Sihoon,Tran, Nghiem Xuan,Kim, Sung-Ryul Elsevier 2017 Applied ocean research Vol.68 No.-

<P><B>Abstract</B></P> <P>A series of 1g model tests was conducted to investigate the accumulated vertical pullout displacement and unloading stiffness of bucket foundations embedded in dry and saturated sands. The foundations were subjected to vertical pullout cyclic loading with different load amplitudes. Cyclic load was applied up to 10<SUP>4</SUP> cycles. Test results showed that the accumulated vertical pullout displacement increased with the increase in the number of load cycles and cyclic load amplitudes. The unloading stiffness of the bucket foundations decreased with the increase in load amplitude and number of cycles. Empirical equations were proposed based on the test results to evaluate the accumulated vertical pullout displacement and unloading stiffness of the bucket foundations in saturated sand. These equations can be used for the preliminary design of single or tripod bucket foundations.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cyclic response of bucket foundations in saturated sand under cyclic vertical pullout load was examined by 1 <I>g</I> model tests. </LI> <LI> Accumulated displacement increased with the increase in number of load cycles and load magnitude. </LI> <LI> Unloading stiffness decreased with the increase in number of load cycles and load magnitude. </LI> <LI> Empirical equations have been proposed. </LI> </UL> </P>

A Cell-based Smoothed Finite Element Method for Three Dimensional Solid Structures

Hung Nguyen-Xuan,Hiep Vinh Nguyen,Stephane Bordas,Timon Rabczuk,Marc Duflot 대한토목학회 2012 KSCE JOURNAL OF CIVIL ENGINEERING Vol.16 No.7

This paper extends further the strain smoothing technique in finite elements to 8-noded hexahedral elements (CS-FEM-H8). The idea behind the present method is similar to the cell-based smoothed 4-noded quadrilateral finite elements (CS-FEM-Q4). In CSFEM,the smoothing domains are created based on elements, and each element can be further subdivided into 1 or several smoothing cells. It is observed that: 1) The CS-FEM using a single smoothing cell can produce higher stress accuracy, but insufficient rank and poor displacement accuracy; 2) The CS-FEM using several smoothing cells has proper rank, good displacement accuracy, but lower stress accuracy, especially for nearly incompressible and bending dominant problems. We therefore propose 1) an extension of strain smoothing to 8-noded hexahedral elements and 2) an alternative CS-FEM form, which associates the single smoothing cell issue with multi-smoothing cell one via a stabilization technique. Several numerical examples are provided to show the reliability and accuracy of the present formulation.