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Purpose: This study aims to investigate the impact of AI chatbots on customer trust in AI chatbots for hotel services. Design/methodology/approach: The probability sampling method was employed to develop a research sample. The research uses correlation analysis and structural equation modeling to analyze the data of 413 valid observations collected in the structured questionnaire survey in Vietnam. Findings: The paper reports that empathy response, anonymity and customization significantly impact interaction. Empathy response is found to be the strongest influence on interaction. Meanwhile, empathy response and anonymity were revealed to indirectly affect customer trust. This paper also contributes several implications for hotel providers in emerging economies. Originality/value: To the best of the authors’ knowledge, this is the first study to shed light on the role of AI chatbots in explaining customers’ behavior. The results provide an enhanced understanding of how the AI chatbot system influences customers’ decision-making. It has been used to plan the chatbot application and highlight which implementation issues need the most attention in the hospitality industry.

The rapid development of the Internet of Things (IoT) devices led to new era in the maritime and road transportation industry and research. This article studies the critical determinants of Drone delivery services (personal innovativeness, outcome expectancy, positive anticipated emotions, and perceived risk) on customer willingness to use Drone in an emerging economy. The article employs correlation analysis and structural equation modeling (SEM) to analyze the data of 602 valid observations collected in the structured questionnaire survey in Vietnam. Empirical results indicate that outcome expectancy and personal innovativeness positively impact customer attitude and anticipated emotion, while outcome expectancy has the strongest influence. These findings also show that outcome expectancy and personal innovativeness have an effect on customer willingness to use Drone through their positive attitude and positive anticipated emotions. Interestingly, the perceived risk of Drone is considered a moderator in reducing the relationship between customer attitude and willingness to use Drone while it has an insignificant impact on customer emotion and willingness to use.

We propose an algorithm for decentralized optimization in wireless device-to-device (D2D) networks of pervasive devices such as sensors or 5G handsets, in which the signs of stochastic gradient are used for descent steps. Our algorithm has the convergence rate of ${O}$ (1/(nT)) in which ${n}$ is the number of devices and ${T}$ is the number of learning iterations, saving the communication efficiency by at least 64 times when compared with previous results, and being relatively robust to unexpected errors of adversarial scaling in communication. Theoretical claims are verified by numerical results on a standard benchmark dataset.

Purpose: This study examines the direct and indirect impact of environmental belief, nature-based destination image and time perspective on tourist attitude towards ecotourism. Design/methodology/approach: Data was collected through a structured questionnaire survey conducted in Vietnam. The dataset consists of 479 valid responses by Vietnamese tourists. Correlation analysis and structural equation modeling (SEM) were used to test the causal relationships among time perspective, environmental belief, nature-based destination and ecotourism attitude. Confirmatory factor analysis (CFA) is conducted to verify the reliability and validity of each latent construct, and to evaluate the discriminant validity, convergent validity, composition reliability and average variance extracted (AVE) for the latent constructs. Findings: This study finds statistically significant and positive effects of time perspective, environmental belief and nature-based destination image on ecotourism attitude. The results also indicate that environmental belief is found to have statistically significant effects both direct and indirect on ecotourism attitude; its indirect effect is transmitted through nature-based destination image. Our findings demonstrate empirically that tourists are mainly attracted by natural environment sites and that tourists having environmental beliefs are likely to engage in ecotourism than other types of tourism by first influencing their attitude. Research limitations/implications: One limitation is associated with our measurement method, which relies on respondents’ self-ratings of their activities. Second, our study is based on internal consistency assessments for establishing construct reliability and validity, which might be the problem of measurement misspecification in tourism research and hinder us to adequately capture the dynamic nature of the variables and the underlying relationships. Third, the survey is conducted in one specific ecotourism nation like Vietnam, and thus, the findings must also be explained in this case. Practical implications: Policymakers need to pay careful attention to the planning and conservation of local resources, as well as infrastructure, for ecotourism development. Moreover, the management of eco-site needs to maintain ecology properly, provide an authentic ecotourism experience to improve ecotourism destination. Otherwise, ecotourism operators should focus on marketing strategies to increase traditional and natural values and promote eco-friendly social standards for fostering demand. Originality/value: This study examines an integrated model analyzing the impact of time perspective, environmental belief and nature-based destination on tourist attitude towards ecotourism. This study reveals the understanding of how individuals’ view towards belief in environment and location image, influences their attitude to engage in ecotourism. The study provides several implications for practice.

Many identity-based encryption schemes under the k-LIN assumption contain 2k+ 1 group elements in the ciphertext overhead and private keys. In this paper, we push the limit further by constructing an IBE scheme under the k-LIN assumption with 2kgroup elements in the ciphertext overhead and private keys. The schemes have variants with shorter public parameters under the k-SCasc assumption, which is a close assumption to k-LIN. Furthermore, via additional refinements, we also put efforts in reducing the public parameter size of our schemes, under either k-LIN or k-SCasc. While we mainly consider securities in the standard model for our schemes, we also show how to make relatively more efficient schemes secure in the random oracle model. Our technique additionally expands to the scheme of Boneh et al. (CRYPTO 2013) to yield more efficient function-private IBE under the 2-LIN (aka, DLIN) assumption. Overall, the shortened size in ciphertexts and private keys inherently leads to fewer exponentiations and pairings in encryption and decryption, and hence yields schemes with better computational efficiency.

Background: In 2005, more than 90% of Vietnamese households were using adequately iodized salt, and urinary iodine concentration among women of reproductive age was in the optimal range. However, household coverage declined thereafter to 45% in 2011, and urinary iodine concentration levels indicated inadequate iodine intake.Objective: To review the strengths and weaknesses of the Vietnamese universal salt iodization program from its inception to the current day and to discuss why achievements made by 2005 were not sustained.Methods: Qualitative review of program documents and semistructured interviews with national stakeholders.Results: National legislation for mandatory salt iodization was revoked in 2005, and the political importance of the program was downgraded with consequential effects on budget, staff, and authority.Conclusions: The Vietnamese salt iodization program, as it was initially designed and implemented, was unsustainable, as salt iodization was not practiced as an industry norm but as a government-funded activity. An effective and sustainable salt iodization program needs to be reestablished for the long-term elimination of iodine deficiency, building upon lessons learned from the past and programs in neighboring countries. The new program will need to include mandatory legislation, including salt for food processing; industry responsibility for the cost of fortificant; government commitment for enforcement through routine food control systems and monitoring of iodine status through existing health/nutrition assessments; and intersectoral collaboration and management of the program. Many of the lessons would apply equally to universal salt iodization programs in other countries and indeed to food fortification programs in general.

The synthesis and cytotoxicity evaluation of fourteen new chalcones containing 5-fluorouracil were introduced in which nine chalcones as Mannich bases 8a-i were synthesized from 2'-hydroxyacetophenone (1) in three steps including chloromethylation, N-alkylation and Claisen-Schmidt reactions. Other chalcones 14a-e were obtained from Click reaction between 1,3-dipropargyl-5-fluorouracil and azide derivatives of 2',4'-dihydroxychalcone. The bio-assay results showed that 11 chalcones (excluding 8d, 8f and 8h) exhibited cytotoxicity against four human cancer cell lines including Hep-G2, RD, LU-1 and FL in which compound 14e exhibited the most potent cytotoxicity against Hep-G2, RD, LU-1 and FL with IC50 values of 1.48, 10.59, 3.64 and 7.02 μg/mL, respectively.

Twenty-one new chalcones 9a-m (excluding 9e, 9j and 9l) and 10a-m (excluding 10j and 10l), containing nucleobases were synthesized from 2-hydroxyacetophenone (1) by the reactions including chloromethylation, nucleophilic substitution with thymine and uracil, and Claisen-Schmidt reactions. These new chalcones were evaluated for in vitro cytotoxicity against five human cancer cell lines: SK-LU-1, Hep-G2, MCF7, SW480 and P388. The results showed that most of the tested chalcones exhibited inhibitory activity against five cancer cell lines except 10h, and 10i. Among the synthesized chalcones, compound 10c exhibited most potent cytotoxicity against MCF-7, SK-LU-1, SW480, HepG2 and P388 with IC50 values of 4.42, 4.81, 5.27, 3.67 and 4.11μg/mL, respectively.

Chiral bis(oxazolinylphenyl)amines proved to be efficient auxiliary ligands for iron and cobalt catalysts with high activity for asymmetric hydrosilylation of ketones and asymmetric conjugate hydrosilylation of enones.

mesoChlorinated bicyclo[2.2.2]octadienefused porphyrins 2ClnTBCODPs; n= 1–4 have been synthesized by chlorination of the free base TBCODPH21H2 using Nchlorosuccinimide NCS. The chlorinated derivatives were easily separated by column chromatography on silica gel to give 2H2in good yields. This method for the chlorination of porphyrin using NCS is mild, safe, and economic compared with the established procedure for the mesochlorination of porphyrins. We also discovered the unexpected mesochlorination of the porphyrin with dichlorodicyanobenzoquinone DDQ by singleelectron transfer. ClnTBCODPs 2were converted into tetrabenzoporphyrins ClnTBPs 3in 100  yields by retroDiels–Alder reaction. The derived compounds were characterized by NMR spectroscopy, UVVis spectrophotometry, cyclic voltammetry CV, Xray crystallography, and organic fieldeffect transistor OFET characteristics. The introduction of chlorine at the mesopositions of the TBPs drastically changed their electronic and structural properties. The maxima of protonated Cl4TBPH23dH2; λmax= 494, 649, and 707 nm were redshifted by around 50–65 nm relative to those of protonated TBPH2λmax= 431, 605, and 660 nm. The two Qband maxima of the Cl4TBP dication are similar to those of a tetraacenaphthoporphyrin dication λmax= 525, 646, and 702 nm, which has one of the most redshifted Qbands.© WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009

Cobalt ferrite nanoparticles (CFNPs) are emerging as a potential candidate for biomedical applications, such as magnetic hyperthermia therapy (MHT), due to their high saturation magnetisation (MS) and effective magnetic anisotropy constant (Keff) at the nanoscale. For MHT, heating efficiency depends considerably on applied AC magnetic field, particle diameter, and inter-particle interaction. Our study is aimed at developing a superparamagnetic nanosystem based on CFNPs with enhanced specific absorption rate (SAR) for advanced MHT. The CFNPs were synthesised using thermal decomposition of organometallic precursors. Transmission electron microscopy reveals a narrow size distribution of the CFNPs, with average particle sizes of 8 and 11 nm. Magnetic measurements showed high values of MS(~70 emu g?1) and Keff(2-3 × 106erg cm?3). The ferromagnetic behaviour and strong interaction between particles at room temperature are also observed. Large SAR values of the CFNPs are achieved, which are superior to those reported previously in the literature. The high heating efficiencies of the present CFNPs make them a promising candidate for advanced MHT.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.