Characteristics of Evacuation Guidance Sounds for the Visually-Impaired during Fire Alarms

Recently, various intelligent evacuation guidance systems that can be applied in buildings were studied. Technology development for the evacuation of vulnerable people such as the visually-impaired is necessary. Voice guidance is a method used to lead the visually-impaired toward the evacuation route. However, it is necessary to review whether it is possible to hear and understand the voice guidance during the sounding of fire alarms. In this study, simulations were conducted to predict the sound power level of the voice guidance device that can secure an acceptable sound transmission index of the guide sound and the appropriate distance from the voice guidance device, when a fire alarm sound is generated in a hallway space. The study found that an acceptable sound transmission index was achieved when the sound power level was 100 dB and the appropriate type of sound device was found to be a necklace-type headset or a regular headphone.

Acoustic quality assessment in a classroom through simulations and measurements

The acoustic quality in a classroom directly impacts the educational relationship between the student and the teacher, reducing speech intelligibility. In addition, inadequate acoustic comfort burdens the vocal health of teachers. This study evaluated a classroom at the Federal University of Paraná, Campus Centro Politécnico, to verify its acoustic quality. The measurements of the acoustics descriptors: Reverberation Time (RT), Definition (D50), Central Time (Ts), Early Decay Time (EDT) were performed according to the ISO 3382-2 standard, concerning Noise Curves (NC) and Background Noise (BGN) these were evaluated by the NBR 10152 and S12.2 standards. The Speech Transmission Index (STI) was measured according to IEC 60268-16 and evaluated according to ISO 9921. The useful-detrimental ratio (U50) and the other descriptors were simulated in the ODEON software version 11. Thus, the results showed that the evaluated room did not meet the minimum requirements in terms of acoustic quality, for the descriptors RT, STI, Ts, D50, RF, and NC. Simultaneously, the RT and STI were also outside the limits established by the German and Finnish standards. Therefore, it is concluded that the evaluated classroom did not reach the minimum acoustic quality requirements.

Environmental noise perception by students and teachers and simulation of the Speech Transmission Index

As diverse as the knowledge transmission techniques aided by multimedia resources are, nothing replaces the teacher-student relationship, which is developed in the classrooms. Therefore, classrooms must offer the necessary conditions for the satisfactory development of teaching and learning activities. In this context, the importance of classroom acoustics is highlighted. The Speech Transmission Index (STI) is one of the broadest and most important parameters to measure speech intelligibility. STI weighs the effects that can cause deterioration on the voice signal, such as the reverberation time and background noise. This work presents an evaluation of the acoustic performance of classrooms using the STI. For that, three constructive patterns were evaluated. The constructive models were named 010, 022 and 023. Students and teachers answered a questionnaire about the perception of noise in the classroom and at school, and the constructive pattern 023 was studied. Computer simulations were performed with ODEON software to precited STI. The results of the measurements and the questionnaires revealed that the noise that disturbs the activities in the classroom comes from the school itself, not only from the other classrooms, corridors and adjacent patios, but also from inside the classroom itself.

Deteksi Transmisi Transovarial Virus Dengue PadaAedes AegyptiPada Wilayah Endemis Kota Pontianak

Dengue virus is highly pathogenic in humans and spreads rapidly through Aedes aegypti and Aedes albopictus mosquitoes. More than half a billion people from 100 countries in the world are at serious risk of dengue virus infection. The purpose of this study was to prove the existence of transovarial transmission of dengue virus in Aedes aegypti mosquitoes with a transovarial transmission index (TTI) in endemic areas in Pontianak, West Kalimantan. This research method is descriptive observational with a cross-sectional study. The results of the Microscopic Examination of Head Squash Preparations on the Aedes aegypti mosquito, showed the Transovarial Transmission Index in Batulayang Village was 39.60% higher, compared to Sungai Jawi Village, which was 29.30%, but both were still lower than ITT in 2012. The results of the Aedes mosquito examination aegypti using the Polymerase Chain Reaction Transcription Reaction (PCR-TR) method found the dengue virus strain. The conclusion of this study proves that the transovarial transmission of dengue virus in Aedes aegypti mosquitoes in Sungai Jawi Village is 29.30% lower than in Batulayang Village by 39.60%, and the dengue virus serotype, DENV-3, has been found.Keywords: transovarial transmission; dengue virus; Aedes aegypti AbstrakVirus Dengue sangat patogen pada manusia dan menyebar dengan cepat melalui nyamuk Aedes aegypti dan Aedes albopictus. Lebih dari setengah miliar penduduk dari 100 negara di dunia berada pada risiko serius infeksi virus dengue. Tujuan dari penelitian ini adalah untuk membuktikan adanya penularan virus dengue transovarial pada nyamuk Aedes aegypti dengan indeks transmisi transovarial (TTI) di daerah Endemis di Pontianak, Kalimantan Barat. Metode penelitian ini adalah deskriptif observasional dengan studi potong lintang. Hasil Pemeriksaan Mikroskopis Sediaan Head Squash pada nyamuk Aedes aegypti, menunjukan Indeks Transmisi Transovarial pada Kelurahan Batulayang lebih tinggi yaitu 39,60%, dibandingkan dengan Kelurahan Sungai Jawi yaitu 29,30%, tetapi keduanya masih lebih rendah dibandingkan ITT pada Tahun 2012. Hasil pemeriksaan nyamuk Aedes aegypti dengan metode Polymerase Chain Reaction Transcription Reaction(PCR-TR) ditemukan strain virus Dengue-3. Kesimpulan penelitian ini membuktikan adanya transmisi transovarial virus dengue pada nyamuk Aedes aegypti di Kelurahan Sungai Jawi sebesar 29,30% lebih rendah dibandingkan di kelurahan Batulayang sebesar 39,60%, serta berhasil ditemukan serotipe virus Dengue yaitu DENV-3.Kata Kunci : transmisi transovarial; virus dengue; Aedes aegypti

Whole Genome Sequencing of Drug Resistant and Drug Susceptible Mycobacterium tuberculosis Isolates From Tigray Region, Ethiopia

Background: Tuberculosis, mainly caused by Mycobacterium tuberculosis (Mtb), is an ancient human disease that gravely affects millions of people annually. We wanted to explore the genetic diversity and lineage-specific association of Mtb with drug resistance among pulmonary tuberculosis patients.Methods: Sputum samples were collected from pulmonary tuberculosis patients at six different healthcare institutions in Tigray, Ethiopia, between July 2018 and August 2019. DNA was extracted from 74 Mtb complex isolates for whole-genome sequencing (WGS). All genomes were typed and screened for mutations with known associations with antimicrobial resistance using in silico methods, and results were cross-verified with wet lab methods.Results: Lineage (L) 4 (55.8%) was predominant, followed by L3 (41.2%); L1 (1.5%) and L2 (1.5%) occurred rarely. The most frequently detected sublineage was CAS (38.2%), followed by Ural (29.4%), and Haarlem (11.8%). The recent transmission index (RTI) was relatively low. L4 and Ural strains were more resistant than the other strains to any anti-TB drug (P < 0.05). The most frequent mutations to RIF, INH, EMB, SM, PZA, ETH, FLQs, and 2nd-line injectable drugs occurred at rpoB S450L, katG S315T, embB M306I/V, rpsL K43R, pncA V139A, ethA M1R, gyrA D94G, and rrs A1401G, respectively. Disputed rpoB mutations were also shown in four (16%) of RIF-resistant isolates.Conclusion: Our WGS analysis revealed the presence of diverse Mtb genotypes. The presence of a significant proportion of disputed rpoB mutations highlighted the need to establish a WGS facility at the regional level to monitor drug-resistant mutations. This will help control the transmission of DR-TB and ultimately contribute to the attainment of 100% DST coverage for TB patients as per the End TB strategy.

Optimum Seeking of Redundant Actuators for M-RCM 3-UPU Parallel Mechanism

The singularity problem brings troubles to the design and application for the parallel mechanism. Currently, redundant actuation is one of the useful methods to solve this singularity problem. However, faced to the numerous joints in a parallel mechanism, how to make a quantitative criterion of seeking the most efficient joints added actuators for letting the mechanism passes through singularity is a necessarily open issue. This paper focuses on a 2R1T 3-UPU (U for universal joint and P for prismatic joint) parallel mechanism (PM) with two rotational and one translational (2R1T) degrees of freedom (DOFs) and the ability of multiple remote centers of motion (M-RCM). The singularity analysis based on the indexes of motion/force transmissibility and constraint shows that this PM has transmission singularity, constraint singularity, mixed singularity and limb singularity. To solve these singular problems, the quantifiable redundancy transmission index (RTI) and the redundancy constraint index (RCI) are proposed for optimum seeking of redundant actuators for this PM. Then the appropriate redundant actuators are selected and the working scheme for redundant actuators near the corresponding singular configuration are given to help the PM passes through the singularity. This research proposes a quantitative criterion to optimum seeking of redundant actuators for the parallel mechanism to solve its singularity.

STI direct test method based on wavelet transform to extract envelope

Speech transmission index (STI for short) is an important index to evaluate the quality of speech transmission of the room, it can better reflect the degree of voice signal affected by room reverberation and noise in the transmission process.This paper presents an algorithm for directly measuring STI index, white noise is filtered by Paul Kellet filter to generate pink noise, the signal envelope is extracted by wavelet transform, which improves the extraction accuracy of signal envelope and makes the measurement of STI index more accurate.

Operation Safety of a 2-DoF Planar Mechanism for Arm Rehabilitation

The operation safety of rehabilitation devices must be addressed early in the development process and before being tested on people. In this paper, the operation safety of a 2-DoF (degrees of freedom) planar mechanism for arm rehabilitation is addressed. Then, the safety and efficiency of the device operation is assessed through the Transmission Index (TI) distribution in its workspace. Furthermore, the produced stresses on the human arm are assessed via the FEM (finite element method) when the rehabilitation device reaches five critical positions within its workspace. The TI distribution showed that the proposed design has a proper behaviour from a force transmission point of view, avoiding any singular configuration that might cause a control failure and subsequent risk for the user and supporting the user’s motion with a good efficiency throughout its operational workspace. The FEM analysis showed that Nurse operation is safe for the human arm since a negligible maximum stress of 6.55 × 103 N/m2 is achieved by the human arm when the device is located on the evaluated critical positions.