Using mobile sinks in wireless sensor networks to improve building emergency response.

We propose an opportunistic routing scheme for wireless sensor networks operating in volatile environments. In particular, we consider a sensor field for sensing and reporting on buildings during fires, where sensors are progressively being destroyed by the fire. We envisage firefighters equipped with small computers which can act as mobile sink nodes, offering transient shorter routes for relaying data, and offering connectivity to disconnected areas of the network. We examine different ways in which these uncontrolled mobile sinks could enhance performance, and develop protocols for advertising the presence of the mobile sinks, gathering data for forwarding, and prioritising disconnected regions. We evaluate the performance in simulation, and on randomly damaged networks, we show that we can increase the data delivery by up to 50%

Doctor of Philosophy

dissertationThe behavior of foam films is significant in many areas such as mineral flotation, food processing, and oil recovery. The film stability between two bubbles in foams has been motivated by different research interests. This dissertation contributes to the understanding of the film stability based on several methods of evaluation. First, the structure of thin water films during the rupture process was investigated by a new approach, which combines molecular dynamics simulation (MDS) with image processing analysis. The procedure was developed to convert the MDS trajectories to readable 3D images. The films were studied at different thicknesses by MDS to determine the critical thickness at which film ruptures. The potential energy of each thickness during simulation time was analyzed. A new procedure involving the calculation of molecular porosity was developed. Results indicate a critical molecular porosity value of 49% for film rupture. Second, disjoining pressure (DP) in thin films was examined by using Matlab. The surface charge regulation approach was applied to develop a new model for computing of DP. The case of sodium dodecyl sulfate (SDS) adsorption from NaCl solution was studied. A model of film drainage rate was developed accordingly which showed a good agreement with experimental data from the literature. Finally, features of interfacial water at air-water interfaces of anionic SDS and cationic dodecyl amine hydrochloride (DDA) solutions were examined by combining sum frequency generation (SFG) vibrational spectroscopy measurements and MDS. The SFG spectra and MDS results revealed that interfacial waters for SDS solutions was highly-ordered compared with those for DDA solutions. SFG results revealed that interfacial waters at pH 9 in both SDS and DDA solutions showed less-ordered than at pH 7. Experiments on foam stability and foam weight were conducted under the same conditions. Results revealed that for SDS solutions, foams were more stable at pH 7 than at pH 9. The opposite was observed for DDA solutions, in which case stability decreased when pH increased. Results were explained based on the extent of surfactant hydration at interfaces which is thought to account for film stability as revealed from results on foam stability

Epidemiology of rotavirus in Southern Vietnam : results of a sentinel surveillance from 2013 to 2018

Rotavirus infects nearly every child by the age of 3–5 years and is the leading cause of severe, dehydrating diarrhea in children aged <5 years worldwide. In Vietnam, nearly haft of diarrhea-related deaths are accounted for Rotavirus; the country also had one of the highest Rotavirus hospitalization figures in South East Asia. The two Rotavirus vaccines (Rotarix and Rotateq) were licensed in the state and available in the private sector, as well as Rotavin-M1 - a local licensed vaccine. In 1998, the Rotavirus sentinel surveillance was initiated in Vietnam. This study aimed to describe the Rotavirus sentinel surveillance findings from 2013 to 2018, including epics profile, clinical features, and genotyping information among hospitalized children under five years of age. Methods: A hospital-based study was performed from the Rotavirus sentinel surveillance at Paediatric Hospital No.1 in Ho Chi Minh city, Vietnam. Data were collected from children between 0 and 59 months of age whose primary reason for hospitalization was acute watery diarrhea. Children were included in the vaccine effectiveness analysis (VE) if they were at least six months old at the time of notification. Results: During 2013-2018, of 5,179 acute diarrhea cases included in the study, Rotavirus was detected in 2,424 cases (46.80%), a downward trend was observed from 2013 (55.27%) to 2018 (43.54%). Dry season months (from November to April) witnessed a 2.4 times higher occurrence of Rotavirus positive cases compared to rainy season months (May to October) (OR=2.4, 95% CI: 2.14 - 2.692, p<0.001). The mortality rate was 0.04%. The typical symptoms associated with Rotavirus AGE were vomiting (present of vomiting, average max number per day, duration), dehydration status, present of fever, diarrhea (average max number per day) (p<0.05). Rotavirus AGE was more likely to be severe than the negative group (p<0.001). Of 1,107 Rotavirus positive cases had PCR isolated for genotyping, G3P[8] was the most common G-P combined genotype (43.18%), followed by G8P[8], G1P[8], G2P[4] (constituted 19.69%, 12.92%, and 12.83%, respectively). We observed an enormous genotyping shift from 2013 to 2018: G3P[8] became more frequent during 2014-2018, with the rise from 8.13% in 2013 to a peak of 60.65% in 2017, then decreased to 41.15% in 2018. In contrast, G1P[8] considerably dropped from 69.92% in 2013 to no case in 2018. There also occurred a change in G8P[8] and G2P[4] prevalence. From no case in 2013, G8P[8] leaped to a peak of 47.21% in 2016 and was the predominant genotype at that year, before went down to 23.92% in 2018. G2P[4] showed a slight upward trend from 2013 to 2014 (from 15.45% to 37.41%), then dropped to 0.43% in 2016, before went up to 16.27% in 2018. The percentage of vaccinees among the study population was meager (3.84%). Among children ≥ 6 months of age, getting a completed schedule of Rotavirus vaccine in general, and the Rotarix vaccine in particular, had vaccine effectiveness against Rotavirus AGE at 82.34% (95% CI: 70.33%-89.49%), and 85.90% (95% CI: 74.10%-92.30%), respectively. Rotarix VE for G3P[8] was 88.35% (95% CI: 52.50%-97.14%). Conclusions: The findings in our study suggested that Rotavirus infection was still a significant cause of acute watery diarrhea among hospitalized children younger than five years old in Vietnam. There is a need to consider the recommended vaccine to use in the National Immunization Program in the dramatic genotyping shift situation. In addition to monitoring genotypes, whole genomic characterization of circulating Rotavirus strains before and after vaccine introduction will help to assess the vaccines' efficacy.open석

Optimization of a genotyping scheme for Treponema pallidum subsp. pallidum including markers for macrolide resistance

Syfilis er en seksuelt overførbar infeksjon, og er et viktig folkehelseproblem både i Norge og i verden. Forekomst av syfilis har økt i de senere årene, spesielt blant menn som har sex med menn (MSM). Bakterien Treponema pallidum subspecies pallidum (TPA), en spiroket som ikke lar seg dyrke, er årsaken til syfilis. Diagnostisering av syfilis gjøres ved hjelp av antistofftest mot TPA antigen, eller ved direkte identifisering av TPA DNA med polymerasekjedereaksjon (PCR). Ubehandlet syfilisinfeksjon, kan deles inn i ulike stadier som gir forskjellige symptomer: primær, sekundær, latent og tertiær. Det er ikke utviklet noen vaksine mot TPA. Penicillin er førstevalg ved behandling av syfilis. Azitromycin, et makrolidantibiotikum, har også vært anvendt i behandling av syfilis og brukes også i behandling av andre kjønnssykdommer. Resistens mot makrolidantibiotika i TPA har imidlertid blitt detektert globalt. TPA kan deles inn i to hovedgrupper utfra molekylær subtyping: Nichols- og SS14- stammer. Kombinasjonen av molekylær genotyping av TPA og resistens mot makrolidantibiotika er viktig for å forstå epidemiologien ved syfilis i Norge, og overvåkning av antibiotikaresistens. Genotypiskbestemmelse av TPA, inkludert markører for makrolidresistens, må først optimaliseres og etableres. Molekylær subtyping av TPA utføres ved multilokus sekvens typing (MLST) av tre loci: TP0136, TP0548 og TP0705. MLST består av en nested PCR etterfulgt av Sanger sekvensering for hvert locus. Allele profiler og sekvenstyper blir bestemt av PubMLST. For deteksjon av makrolidresistente TPA, som skyldes punktmutasjonene A2058G eller A2059G i ett eller begge kopier av 23S rRNA-genet, ble det utviklet en SimpleProbe real-time PCR analyse etterfulgt av en smeltepunktsanalyse. Makrolidresistente TPA har en lavere smeltepunkts-temperatur enn villtype TPA. Det ble samlet inn 81 pasientprøver fra oktober 2020 til september 2022. Ved molekylær subtyping ble det avdekket ni forskjellige sekvenstyper, deriblant tre nye sekvenstyper. Makrolidresistens kan også bekreftes blant disse prøvene.Syphilis, a sexually transmitted disease, is an important public health problem, both in Norway and worldwide. The incidence of syphilis has increased in the recent years, particularly among men who have sex with men (MSM). Infection with the uncultivated spirochaete bacteria Treponema pallidum subsp. pallidum (TPA), is the cause of syphilis. Syphilis can be diagnosed with antibody test against TPA antigen or by directly identification of TPA DNA with polymerase chain reaction (PCR). Untreated syphilis infection can be divided into different stages that give different symptoms: primary, secondary, latent, and tertiary. No vaccine against TPA has been developed yet. Penicillin is the first choice of antibiotic treatment for syphilis. Azithromycin, a macrolide antibiotic, has shown to be an effective treatment of early syphilis in many cases as well as treating infections with other venereal diseases. However, macrolide antibiotic resistance in TPA has been detected globally. By molecular characterization, TPA can be divided into two main lineages: Nichols- and SS14-like strains. The combination of molecular genotyping of TPA and macrolide antibiotic resistance is important for understanding the epidemiology of syphilis in Norway, and the surveillance of antibiotic resistance. Thus, a genotyping scheme for TPA including markers for macrolide resistance, need to be established and optimized. Molecular characterization of TPA was performed by multi-locus sequence typing (MLST) of three loci: TP0136, TP0548, and TP0705. MLST consists of a nested PCR followed by Sanger sequencing of each of the three loci. The allelic profiles and sequence type can be determined by PubMLST. For detection of macrolide resistance in TPA, due to point mutations in position A2058G or A2059G in one or both copies of the 23S rRNA gene, a SimpleProbe real-time PCR assay was developed followed by a melting point analysis. Macrolide resistance in TPA is detected by having a lower melting temperature than the wild-type. Eighty-one clinical samples were collected from October 2020 to September 2022. Molecular characterization of TPA revealed nine different sequence types, including three novel sequence types. Macrolide resistance was also confirmed among the collected samples

An Evaluation of Satisfaction Levels Among Chinese Tourists in Vietnam

This paper examines the extent to which Vietnam satisfi es the various destination attributes sought by Chinese tourists. The research investigates a number of variables, including socio-demographics and travel characteristics, and compares the importance that travellers attach to various destination attributes with their associated satisfaction with Vietnam’s various tourism products. By investigating the relationship between importance and satisfaction from the perspective of Chinese tourists, the paper makes a contribution to the literature. The fi ndings should provide Vietnamese service providers with insights into the perceptions and satisfaction levels of Chinese tourists

Building forecast maps of water quaůity for main rivers and canals in Tien Giang province, Vietnam

This study aims to enhance the mapping of forecast for water quality assessment in Mekong Delta provinces. The data from 32 sites from main rivers and canals in an area of around 2,482 km2 in Tien Giang Province, Vietnam, were used for calculation and mapping. The ArcGIS 9.3 software, Inverse Distance Weighting (IDW) interpolation method, hydrologic data, and water quality parameters in March (2010-2014) were applied to build the maps showing 2020 water quality predictions for main rivers and canals in Tien Giang Province. The estimation was based on the Water Quality Index (WQI) with 6 parameters such as pH, total suspended solid (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD), total nitrogen (T_N), and coliform. The results showed that water quality in the studied area in dry season will not be improved by the year 2020. The finding could be a scientific reference for the selection of effective approaches to improve water quality in main rivers and canals in Tien Giang Province

Input Adjustment Between and Within Equity Sensitivity Groups

Previous research on Equity Sensitivity have focused on each type’s (Entitled, Benevolents, and Equity Sensitives) reaction to inequity based on preferences for input/output ratios in comparison to a referent other and sensitivity to the norm of reciprocity (Huseman et al., 1987). The purpose of this study is to better understand how individuals in each of the Equity Sensitivity categories act on their preferences for input/output ratios when paired with referents from the same or different ES categories. We will examine whether the individual will react in the expected manner regardless of the category to which the referent belongs, or whether social comparison or social desirability impact their behavior. Participants’ levels of equity sensitivity will be measured using the Equity Sensitivity Instrument (ESI, Huseman et al., 1985, 1987). They will then be presented with three hypothetical situations that pair them with an individual from one of the Equity Sensitivity categories. The participant will then be asked how much work (input) they will put into the task and how satisfied they would be working with that individual. Results could provide insight into how levels of Equity Sensitivity in dyadic relationships impact the level of effort an individual is willing to put into a collaborative task, and ultimately whether, and potentially why, ES impacts performance

Modern Architecture in Vietnam or Vietnamese Modern Architecture?

Architecture is one of the keys to the values of a society, a reflection of a people’s aspiration, and a society’s ideas and technological experiments over periods in its history. This paper will address “modern architecture in Vietnam” focusing on the general course of its development: its practice, discourse and the built environment throughout history. The guiding questions for the main content of this paper are very fundamental: How can we define modern architecture in Vietnam? How was it formed and developed through the modern history of the country? Can we call modern architecture in Vietnam “Vietnamese modern architecture”

Research on Factors Affecting the Intention to Maintain a Long-Term Relationship in Franchising in Vietnam

Purpose: This study examines the factors in franchising that influence satisfaction and intention to maintain a long-term relationship.   Theoretical framework: This study applies the theory of consumer behavior to prove that the factors of cooperation, support, trust, commitment, brand value, and commitment are the factors that affect customer satisfaction through table design.   Design/Methodology/Approach: This study obtained 386 valid answers that were coded and cleaned using SPSS and AMOS software, after cleaning and coding, the reliability test, exploratory factor analysis, and confirmatory factor analysis were carried out to determine CFA and test the SEM hypothesis.   Findings:  This study shows that four independent factors are trust, cooperation, brand value, and cost, which are factors that indirectly affect the intention to maintain the relationship in franchising, franchise through the intermediate variable is satisfaction.   Research, Practical &amp; Social implications: This study proposes a number of governance implications to increase the intention to maintain the franchisor-franchise relationship.   Originality/Value: This study examined the factors that indirectly affect the intention to maintain the relationship in the franchise system through the mediating variable. At the same time, the study also tries to clarify how the influence of the identified factors has an indirect effect on the intention to maintain a relationship in the franchise