scholarly journals Two-stage Localisation Scheme Using a Small-scale Linear Microphone Array for Indoor Environments

2015 ◽  
Vol 68 (5) ◽  
pp. 915-936 ◽  
Author(s):  
Wuyang Jiang ◽  
Ling Pei ◽  
Changqing Xu ◽  
Liang Chen ◽  
Wenxian Yu

The small-scale linear microphone arrays that are widely found in smartphones could be used to locate a sound source for indoor environments. After the Time Differences Of Arrival (TDOAs) in microphone pairs are estimated, a TDOA-based hybrid localisation scheme is proposed for a small-scale linear microphone array. The scheme contains two stages: the initialisation stage using the Levenberg-Marquardt (LM) algorithm, and the refining solution stage using the Weighted Least-Square (WLS) algorithm or the Multi-Dimensional Scaling-based (MDS) algorithm. Simulations and field tests show that the proposed indoor localisation scheme outperforms the existing schemes, and it can achieve an average error of 0·32 metres in an 8 m by 5 m area.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Y. Song ◽  
H. Chun

AbstractVolatile organic compounds (VOCs) are secondary pollutant precursors having adverse impacts on the environment and human health. Although VOC emissions, their sources, and impacts have been investigated, the focus has been on large-scale industrial sources or indoor environments; studies on relatively small-scale enterprises (e.g., auto-repair workshops) are lacking. Here, we performed field VOC measurements for an auto-repair painting facility in Korea and analyzed the characteristics of VOCs emitted from the main painting workshop (top coat). The total VOC concentration was 5069–8058 ppb, and 24–35 species were detected. The VOCs were mainly identified as butyl acetate, toluene, ethylbenzene, and xylene compounds. VOC characteristics differed depending on the paint type. Butyl acetate had the highest concentration in both water- and oil-based paints; however, its concentration and proportion were higher in the former (3256 ppb, 65.5%) than in the latter (2449 ppb, 31.1%). Comparing VOC concentration before and after passing through adsorption systems, concentrations of most VOCs were lower at the outlets than the inlets of the adsorption systems, but were found to be high at the outlets in some workshops. These results provide a theoretical basis for developing effective VOC control systems and managing VOC emissions from auto-repair painting workshops.


2019 ◽  
Vol 283 ◽  
pp. 04001
Author(s):  
Boquan Yang ◽  
Shengguo Shi ◽  
Desen Yang

Recently, spherical microphone arrays (SMA) have become increasingly significant for source localization and identification in three dimension due to its spherical symmetry. However, conventional Spherical Harmonic Beamforming (SHB) based on SMA has limitations, such as poor resolution and high side-lobe levels in image maps. To overcome these limitations, this paper employs the iterative generalized inverse beamforming algorithm with a virtual extrapolated open spherical microphone array. The sidelobes can be suppressed and the main-lobe can be narrowed by introducing the two iteration processes into the generalized inverse beamforming (GIB) algorithm. The instability caused by uncertainties in actual measurements, such as measurement noise and configuration problems in the process of GIB, can be minimized by iteratively redefining the form of regularization matrix and the corresponding GIB localization results. In addition, the poor performance of microphone arrays in the low-frequency range due to the array aperture can be improved by using a virtual extrapolated open spherical array (EA), which has a larger array aperture. The virtual array is obtained by a kind of data preprocessing method through the regularization matrix algorithm. Both results from simulations and experiments show the feasibility and accuracy of the method.


2012 ◽  
Vol 220-223 ◽  
pp. 2445-2449
Author(s):  
Wen Dan Xu ◽  
Xin Quan Lai ◽  
Dong Lai Xu

This paper presents an improved video segmentation scheme, which consists of two stages: initial segmentation and motion estimation. In the initial segmentation, the watershed transformation followed by a region adjacency graph guided region merging process is used to partition the first video frame into spatial homogenous regions. Then the motion of changed region is estimated. Based on the highly efficient quadratic motion model, the motion estimation is undertaken using Gauss-Newton Levenberg-Marquardt method to minimize the least-square error function. Experimental results show the proposed scheme provides high performance in terms of segmentation accuracy and video compression ratio.


2016 ◽  
Vol 4 (1) ◽  
pp. 34
Author(s):  
Muna Aprilianto ◽  
Tomoliyus Tomoliyus

Penelitian ini bertujuan untuk menghasilkan buku pedoman bermain sepakbola untuk meningkatkan aspek psikologis (semangat, gembira, dan disiplin) anak usia 12-13 tahun di Yogyakarta. Penelitian ini merupakan penelitian dan pengembangan yang terdiri atas dua tahapan yaitu tahap penelitian pendahuluan terdiri dari kajian literatur, kajian penelitian relevan, studi lapangan dan tahap pengembangan terdiri perencanaan, validasi ahli, uji skala kecil, dan uji skala besar. Peneliti ini mengambil sampel dari sekolah sepakbola di Yogyakarta. Teknik sampling yang digunakan adalah purposive sampling. Pada uji coba skala kecil dilakukan di SSB Real Madrid melibatkan 10 siswa dan satu orang pelatih. Pada uji coba skala besar dilakukan di dua tempat yaitu di SSB Real Madrid dan SSB Bina Putra Jaya Sleman melibatkan 38 siswa dan dua pelatih. Analsis data dalam penelitian ini menggunakan teknik analisis deskriptif kuantitatif dan kualitatif. Hasil validasi menunjukkan model bermain sepakbola anak usia 12-13 tahun layak untuk diuji cobakan. Berdasarkan Hasil pelaksanaan pada uji coba skala kecil dan besar secara substansi isi dan pelaksanaan tergolong sangat baik. Hasil penilaian efektivitas model tehadap psikologis anak berupa semangat, gembira, dan disiplin mengalami peningkatan: nilai pertemuan kedua lebih tinggi dari pertemuan pertama. Dapat disimpulkan model bermain sepakbola anak usia 12-13 tahun efektif untuk meningkatkan aspek psikologis berupa semangat, gembira, dan disiplin siswa dalam melakukan latihan sepakbola.Kata Kunci: model, bermain, psikologis, sekolah sepakbola Development a playing soccer model to improve the psychological aspects of 12-13 years old children in Yogyakarta AbstractThis research aims to develop a playing soccer model to improve the psychological aspects (spirit, joy, and discipline) of 12-13 years old children in Yogyakarta. This study is a research and development which consists of two stages. The Preliminary research stage and development stage. The Preliminary research stage consisted of a literature review, relevant research studies and field studies. The Development stage consisted of planning, validation expert, small-scale test, and test large scale. The Validation involve three people experts. The sampel of take it from soccer school in Yogyakarta. The small-scale tryout was conducted on 10 students and one coach of Real Madrid Soccer School in Yogyakarta. The large-scale trials were conducted with two soccer school on 38 students and two coach of Yogyakarta Real Madrid Soccer School and Sleman Bina Putra Jaya Soccer School. The resul is a playing soccer model for children aged 12-13 years with the title "Playing Soccer in Practice to Improve Psychological Aspects". Based on the small-scale tryout and the small-scale tryout content implementation aspects are in an excellent category. The Psychological development of students assessment resulting in the form of passion, joy, and discipline in playing soccer show improvement: score of the second meeting is greater than the average score of the first meeting, thus it can be concluded thaat the playing soccer model for children age 12-13 years is effective to improve students’ psychological aspects, including the aspects of spirit, joy, and discipline in doing soccer practice.Keywords: models, play, psychological, soccer school


2014 ◽  
Vol 39 (3) ◽  
pp. 232-237 ◽  
Author(s):  
Bryce Dyer

Background/Objectives: This study introduces the importance of the aerodynamics to prosthetic limb design for athletes with either a lower-limb or upper-limb amputation. Study design: The study comprises two elements: 1) An initial experiment investigating the stability of outdoor velodrome-based field tests, and 2) An experiment evaluating the application of outdoor velodrome aerodynamic field tests to detect small-scale changes in aerodynamic drag respective of prosthetic limb componentry changes. Methods: An outdoor field-testing method is used to detect small and repeatable changes in the aerodynamic drag of an able-bodied cyclist. These changes were made at levels typical of alterations in prosthetic componentry. The field-based test method of assessment is used at a smaller level of resolution than previously reported. Results: With a carefully applied protocol, the field test method proved to be statistically stable. The results of the field test experiments demonstrate a noticeable change in overall athlete performance. Aerodynamic refinement of artificial limbs is worthwhile for athletes looking to maximise their competitive performance. Conclusion: A field-testing method illustrates the importance of the aerodynamic optimisation of prosthetic limb components. The field-testing protocol undertaken in this study gives an accessible and affordable means of doing so by prosthetists and sports engineers. Clinical relevance Using simple and accessible field-testing methods, this exploratory experiment demonstrates how small changes to riders’ equipment, consummate of the scale of a small change in prosthetics componentry, can affect the performance of an athlete. Prosthetists should consider such opportunities for performance enhancement when possible.


1997 ◽  
Vol 41 (01) ◽  
pp. 69-80
Author(s):  
Mark D. Bracco ◽  
Tomasz Wierzbicki

This paper studies the cutting by a wedge of advanced double hull (ADH) small-scale models. A total of six cutting experiments were performed with six different wedge geometries. Complex deformation patterns observed in the damaged specimens were simplified to obtain a closed-form upper bound for the steady-state cutting force. The ADH steady-state cutting force solution varied from 6% above to 12% below the experimental mean steady-state force. The absolute average error is 5%.


Author(s):  
Qiang Yang ◽  
Yuanqing Zheng

Voice interaction is friendly and convenient for users. Smart devices such as Amazon Echo allow users to interact with them by voice commands and become increasingly popular in our daily life. In recent years, research works focus on using the microphone array built in smart devices to localize the user's position, which adds additional context information to voice commands. In contrast, few works explore the user's head orientation, which also contains useful context information. For example, when a user says, "turn on the light", the head orientation could infer which light the user is referring to. Existing model-based works require a large number of microphone arrays to form an array network, while machine learning-based approaches need laborious data collection and training workload. The high deployment/usage cost of these methods is unfriendly to users. In this paper, we propose HOE, a model-based system that enables Head Orientation Estimation for smart devices with only two microphone arrays, which requires a lower training overhead than previous approaches. HOE first estimates the user's head orientation candidates by measuring the voice energy radiation pattern. Then, the voice frequency radiation pattern is leveraged to obtain the final result. Real-world experiments are conducted, and the results show that HOE can achieve a median estimation error of 23 degrees. To the best of our knowledge, HOE is the first model-based attempt to estimate the head orientation by only two microphone arrays without the arduous data training overhead.


2018 ◽  
Vol 7 (3.32) ◽  
pp. 59
Author(s):  
Zhylkybaev Oral ◽  
Alimzhanova Mereke ◽  
Ashimuly Kazhybek ◽  
Shoinbekova Sabina ◽  
Tukenova Zulfia

Synthesis of new potential plant growth regulators (analogues of natural phytohormones) is accomplished by mixing an equimolar mixture of aryloxypropin and 1-methylpiperidin-4-one under the conditions of Favorsky's reactions. New derivatives of acetylene aminoalcohols - the ZhOT series - have been obtained. The structure of the synthesized compounds was established by IR and NMR 1H spectroscopy. Screening of their water-soluble forms, on wheat and barley seeds, two preparations (ZhOT-4 and ZhOT-7) were selected, which exceed both the control and standards of known phytohormones, such as heteroauxin (indolyl-3-acetic acid), 6-BAP (6-benzylaminopurine) for further testing. Conducted in-depth laboratory and demonstration field tests on cereals (wheat and barley) showed high efficiency of ZhOT-4 and ZhOT-7, the indicators of which exceeded the well-known reference preparation - Agrostimulin (Ukraine). The growth regulating activity of synthesized compounds was determined. Processing of wheat seeds ZhOT-4 and ZhOT-7 increased the field germination of seeds, plant height, leaf area, the mass of the aerial part and the total area. The conducted studies showed that the biological activity of the tested compounds largely depends on the concentration and the best growth regulator is ZhOT-4. The activity of the synthesized growth regulatory compounds has been determined. Treatment of seeds of with ZhOT-4 and ZhOT-7 increased seed germination, height of plants, leave areas, weight of an elevated part and the total area, weight of an elevated part and the total area. Studies have shown that the biological activity of tested compounds is largely dependent on the concentration and the best growth regulator is ZhОТ-4. Thus, the advanced laboratory and demonstration (small-scale) comparative tests of ZhOT-4 and ZhOT-7 and the well-known reference preparation "Agrostimulin" (Ukraine) for cereals (wheat and barley) showed high efficiency of new synthesized preparations. The use of ZhOT preparations increases the germination and germination energy, the number of spikelets, the mass of grains, the bushiness and the yield of wheat and barley, leads to the accumulation of dry mass in both the ground and underground parts of plants. The advantages of ZhOT-4 and ZhOT-7 are: high efficiency, a wide range of cultures, good solubility in water, low application dose of 0.0001% by active ingredient (1g per 1t of water) or 13-50 mg per hectare, comparable to natural phytohormones, long shelf life, safety, high yield of target products, sequential 3-stage reaction in one reactor. 


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