270 research outputs found
Assessment of Fire Safety for Intermediate Floors in the New Zealand Acceptable Solution C/AS1
This research project aims to investigate the level of risk/safety inherent in intermediate floors of buildings designed to the Compliance Document for the New Zealand Building Code, Fire Safety Clauses C1, C2, C3, C4 (C/AS1), and develop guidance for Fire Engineers on designing fire safety for firecells containing intermediate floors. The project also aims to develop a new set of prescriptive fire safety requirements for intermediate floors and proposes an outline of a verification method for designing fire safety for intermediate floors.
This study includes a literature review of the fire safety requirements for intermediate floors (mezzanines) of prescriptive requirements in New Zealand and other countries such as USA, Canada, UK and Australia. The results of this literature review found that the intermediate floor size is limited and varies with country. An intermediate floor that has an area exceeding the limit set out by the prescriptive requirements is considered as a storey in all the countries prescriptive requirements reviewed including the New Zealand prescriptive requirements prior to 1991. Since 1991, in New Zealand Acceptable Solutions, the intermediate floor that has an area exceeding the limit will not be treated as a storey, however, a smoke control system is required.
The level of risk was quantified using a factor of safety (FoS) - the ratio of Available Safe Egress Time (ASET) to Required Safe Egress Time (RSET). Two fire models; BRANZFIRE and FDS were used to calculate ASET and SIMULEX, an evacuation program, was used to calculate movement times of the occupants of the studied buildings. Unlike the traditional method in which RSET and FoS are assessed using single value, in this project the distribution of RSET and FoS were assessed using the @RISK software package. The analysis showed that the level of risk to the occupants of the firecells containing intermediate floors is always higher than that of the equivalent firecells without intermediate floors with the same occupant load and the differences in FoS range from 10% to 60%. The analysis also highlighted that the level of risk to the occupants of firecells having intermediate floors increases as the intermediate floor size increases, however, there are no clear cut-off points at which a higher level of fire safety precaution should be provided. The cut-off points in C/AS1 of 20% for a closed intermediate floor and 40% for an open intermediate floor, are not justified by this analysis. Occupant load has significant impact on the level of safety of the occupants of the firecells containing intermediate floors. The higher the occupant load the lower the level of safety is.
The definitions for open and closed intermediate floors are proposed to which open and closed intermediate floors are clearly distinguished. The term “limited area intermediate floor” in the current C/AS1 is proposed be removed and all related clauses are proposed to be amended or deleted accordingly. A proposed new set of prescriptive fire safety requirements for intermediate floors has been developed based on the occupant load of intermediate floors and not the intermediate floor size in the form of a table similar to the current Table 4.1 of C/AS1. The occupant load and fire safety precautions (FSPs) of the intermediate floors are determined based on the occupant load and their required FSPs of the equivalent firecells without intermediate floors that have the same factor of safety with the firecells containing intermediate floors. With the proposed FSPs, a firecell with lower occupant load would require lesser fire safety requirements than a firecell with higher occupant load regardless of intermediate floor size. Moreover, with the proposed FSPs for intermediate floors, the level of safety of the occupants of the firecells having intermediate floors would be very similar to the level of safety of the equivalent firecells without intermediate floors. In addition to the proposed tables of FSPs, some clauses regarding the changes in the fire safety requirement and definitions for intermediate floors are proposed.
Guidance for designers in designing fire safety for firecells containing intermediate floors in which the methods of modelling using BRANZFIRE and Fire Dynamics Simulator (FDS) are presented in detail, has been developed. The analysis has pointed out that the location of the exits is critical in designing fire safety for firecells containing intermediate floors and majority of exits from the lower floor should not be located under intermediate floors.
Although one of the main objectives of this research project was to propose an outline of a verification method for designing fire safety for intermediate floors, the analysis showed that it is very difficult to develop a rational verification method for designing fire safety for firecells containing intermediate floors.
Using the proposed FSPs for intermediate floors which are based on the occupant load of the intermediate floors in designing fire safety for firecells containing intermediate floors is recommended by this study. These recommendations do not preclude the use of specific fire engineering design for designing fire safety for firecells having intermediate floors
DYNAMIC MODEL WITH A NEW FORMULATION OF CORIOLIS/CENTRIFUGAL MATRIX FOR ROBOT MANIPULATORS
The paper presents a complete generalized procedure based on the Euler-Lagrange equations to build the matrix form of dynamic equations, called dynamic model, for robot manipulators. In addition, a new formulation of the Coriolis/centrifugal matrix is proposed. The link linear and angular velocities are formulated explicitly. Therefore, the translational and rotational Jacobian matrices can be derived straightforward from definition, which makes the calculation of the generalized inertia matrix more convenient. By using Kronecker product, a new Coriolis/centrifugal matrix formulation is set up directly in matrix-based manner and guarantees the skew symmetry property of robot dynamic equations. This important property is usually exploited for developing many control methodologies. The validation of the proposal formulation is confirmed through the symbolic solution and simulation of a typical robot manipulator
BUILDING TEAM OF EMPLOYEES OF ETHNIC MINORITIES IN THE MOUNTAIN DISTRICTS OF THANH HOA TODAY
During the development period, training and human resource development in general, building a contingent of ethnic minority cadres in particular in mountainous districts has been identified by the Party and State as a special feature. enmity in the overall policy towards ethnic regions. The article, based on clarifying the position, role and current problems in building a contingent of ethnic minority cadres in mountainous districts of Thanh Hoa province, has proposed some solutions. improve the quality of building a contingent of ethnic minority cadres in the mountainous districts of Thanh Hoa
Etiology and epidemiology of diarrhea in children in Hanoi, Vietnam
SummaryObjectivesThis paper provides a preliminary picture of diarrhea with regards to etiology, clinical symptoms, and some related epidemiologic factors in children less than five years of age living in Hanoi, Vietnam.MethodsThe study population included 587 children with diarrhea and 249 age-matched healthy controls. The identification of pathogens was carried out by the conventional methods in combination with ELISA, immunoseparation, and PCR. The antibiotic susceptibility was determined by MIC following the NCCLS recommendations.ResultsOf those with diarrhea, 40.9% were less than one year old and 71.0% were less than two years old. A potential pathogen was identified in 67.3% of children with diarrhea. They were group A rotavirus, diarrheagenic Escherichia coli, Shigella spp, and enterotoxigenic Bacteroides fragilis, with prevalences of 46.7%, 22.5%, 4.7%, and 7.3%, respectively. No Salmonella spp or Vibrio cholerae were isolated. Rotavirus and diarrheagenic E. coli were predominant in children less than two years of age, while Shigella spp, and enterotoxigenic B. fragilis were mostly seen in the older children. Diarrheagenic E. coli and Shigella spp showed high prevalence of resistance to ampicillin, chloramphenicol, and to trimethoprim/sulfamethoxazole. Children attending the hospitals had fever (43.6%), vomiting (53.8%), and dehydration (82.6%). Watery stool was predominant with a prevalence of 66.4%, followed by mucous stool (21.0%). The mean episodes of stools per day was seven, ranging from two to 23 episodes. Before attending hospitals, 162/587 (27.6%) children had been given antibiotics. Overall, more children got diarrhea in (i) poor families; (ii) families where piped water and a latrine were lacking; (iii) families where mothers washed their hands less often before feeding the children; (iv) families where mothers had a low level of education; (v) families where information on health and sanitation less often reached their households.ConclusionsGroup A rotavirus, diarrheagenic Escherichia coli, Shigella spp, and enterotoxigenic Bacteroides fragilis play an important role in causing diarrhea in children in Hanoi, Vietnam. Epidemiological factors such as lack of fresh water supply, unhygienic septic tank, low family income, lack of health information, and low educational level of parents could contribute to the morbidity of diarrhea in children
Vitali's theorem without uniform boundedness
Let {fm}m≥1 be a sequence of holomorphic functions defined on a bounded domain D ⊂ Cn or a sequence of rational functions (1 ≤ deg rm ≤ m) defined on Cn. We are interested infinding sufficient conditions to ensure the convergence of {fm}m≥1 on a large set provided the convergence holds pointwise on a not too small set. This type of result is inspired from a theorem of Vitali which gives a positive answer for uniformly bounded sequence
Тектоническая эволюция южной части Центрального Вьетнама и прилегающей территории
Interpretations of seismic, gravity and magnetic anomalies and structural data on the coastal zone of southern part of Central Viet Nam (SCVN) and the adjacent Tertiary basins suggest several phases in the tectonic evolution of the study region since the Late Cretaceous to Quaternary. In this paper, we try to clarify the tectonic evolution of SCVN and the adjacent continental margin. The Cretaceous – Paleocene tectonic phase commenced after cessation of the West Pacific plutonic magmatic activity that produced numerous diabases and aplite dykes of mainly sub-meridian orientation. It was characterized by N–S compression and E–W extension. The geomorphology and geology ofSE Asiawere considerably changed during the Neotectonic phases caused by collision between the Indian plate and the Eurasian continent. Two tectonic phases – Early and Late Neotectonic – are separated by a regional unconformity represented by a boundary surface between below strongly deformed strata (synrift) and above less deformed formations (post-rift). The Early Neotectonic phase was related to the left-lateral movement of the Red River Fault Zone (RRFZ) and includes two tectonic sub-phases: Eocene – Oligocene (NW–SE compression), and Oligocene – Miocene (E–W compression). Activity in the Oligocene-Miocene sub-phase gave birth to rift basins in the continental margin of the SCVN. The Late Neotectonic phase began since the RRFZ stopped left-lateral movement and the East Viet Nam (orSouth China) Sea stopped spreading. The Late Neotectonic phase is also divided into two tectonic sub-phases: Late Early Miocene (sub-meridian compression), and Late Miocene – Pliocene (NE–SW compression). The Late Miocene – Pliocene sub-phase is characterized by vertical movements that caused episodic uplifting of the onland terrains, and subsidence of the offshore Phu Khanh basin. Besides, Miocene – Pliocene-Quarternary basaltic eruptions were widespread all over the southern Indosinian terrain and the continental margin.Путем интерпретации данных о сейсмических, гравитационных и магнитных аномалиях, а также данных о структуре прибрежной зоны южной части Центрального Вьетнама и прилегающих к нему третичных впадин можно выделить несколько этапов тектонической эволюции изучаемого региона, с позднего мелового до четвертичного периода. Цель статьи – получить более точную картину тектонической эволюции южной части Центрального Вьетнама и прилегающей территории. Тектоническая фаза, датируемая как мел – палеоцен, началась после прекращения глубинного магматизма в западной части Тихого океана, приведшего к образованию многочисленных диабазов и аплитовых даек, ориентированных в основном субмеридионально. В течение этой фазы происходило меридиональное сжатие (С-Ю) и расширение в широтном направлении (З-В). В геоморфологическом и геологическом отношении ЮЗ Азия значительно изменилась в течение неотектонических фаз вследствие столкновения между Индийской плитой и Евразийским континентом. Ранняя и поздняя неотектонические фазы разделены региональным несогласием, которое установлено как поверхность, разграничивающая сильнодеформированные толщи (синрифтовые) и перекрывающие, менее деформированные формации (пострифтовые). Ранняя неотектоническая фаза, связанная с левосторонним смещением в зоне разлома Ред-Ривер, может быть разделена на две тектонические подфазы: эоцен – олигоцен (сжатие в СЗ-ЮВ направлении) и олигоцен – миоцен (широтное сжатие, В-З). В течение подфазы, датируемой как олигоцен – миоцен, возникли рифтовые впадины на континентальной окраине южной части Центрального Вьетнама. Поздняя неотектоническая фаза началась после прекращения сдвигового смещения в зоне разлома Ред-Ривер и прекращения расширения Восточного (Южно-Китайского) моря. Поздняя неотектоническая фаза также может быть разделена на две тектонические подфазы: поздний ранний миоцен (субмеридиональное сжатие) и поздний миоцен – плиоцен (сжатие в СВ-ЮЗ направлении). В течение подфазы, датируемой как поздний миоцен – плиоцен, происходили вертикальные движения, приведшие к формированию ряда поднятий на суше, а также опускания в районе морской впадины Фухань. При этом по всей южной части Индокитая и на континентальной окраине широко распространены миоцен-плиоцен-четвертичные базальтовые извержения
Anti-DreamBooth: Protecting users from personalized text-to-image synthesis
Text-to-image diffusion models are nothing but a revolution, allowing anyone,
even without design skills, to create realistic images from simple text inputs.
With powerful personalization tools like DreamBooth, they can generate images
of a specific person just by learning from his/her few reference images.
However, when misused, such a powerful and convenient tool can produce fake
news or disturbing content targeting any individual victim, posing a severe
negative social impact. In this paper, we explore a defense system called
Anti-DreamBooth against such malicious use of DreamBooth. The system aims to
add subtle noise perturbation to each user's image before publishing in order
to disrupt the generation quality of any DreamBooth model trained on these
perturbed images. We investigate a wide range of algorithms for perturbation
optimization and extensively evaluate them on two facial datasets over various
text-to-image model versions. Despite the complicated formulation of DreamBooth
and Diffusion-based text-to-image models, our methods effectively defend users
from the malicious use of those models. Their effectiveness withstands even
adverse conditions, such as model or prompt/term mismatching between training
and testing. Our code will be available at
\href{https://github.com/VinAIResearch/Anti-DreamBooth.git}{https://github.com/VinAIResearch/Anti-DreamBooth.git}.Comment: Project page: https://anti-dreambooth.github.io
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