Lower Acquisition Costs Research Articles

Effect of solids concentration and operational variables on the performance of a geometrically optimized concentrator hydrocyclone employing a pseudoplastic fluid

The employment of hydrocyclones in thickening operations is an attractive option when compared to centrifuges and filters due to their low operating, maintenance, and acquisition costs. However, the performance of hydrocyclone separation is impaired as the concentration of solids and the viscosity of the suspension increases. Using geometric optimization techniques, the Federal University of Uberlândia developed one concentrator hydrocyclone named HC. When working with diluted and Newtonian slurries, the HC could generate a stream 45 times more concentrated than the one fed into it. In this study, the HC performance was evaluated when operating pseudoplastic fluids containing up to 10% solids by volume. The combination of the underflow diameter and vortex finder length with an adequate supply of pressure energy maintained the thickening potential of the HC even when the rheology of the fluid was changed. For different working suspensions, the HC hydrocyclone achieved a minimum water split to underflow of 5%, a maximum concentration ratio of 7.0, and a maximum efficiency of 49%. The encouraging results obtained by the HC validated the benefits of the geometric optimization, as they point to a significant advance in the thickening operation of non–Newtonian sludges with a flow behavior index greater than 0.5.

A low-cost alternative to LiDAR for site index models: applying repeated digital aerial photogrammetry data in the modelling of forest top height growth

Abstract Environmental and forest structural information derived from remote sensing data has been found suitable for modelling forest height growth and site index and therefore forest productivity assessment, with the advances in airborne laser scanning (ALS) playing a major role in this development. While there is growing interest in the use of ALS-derived point clouds, point clouds from high-resolution digital aerial photography (DAP) are also often used for mapping and estimating forest ecosystem properties due to their lower acquisition costs. In this study, we document the applicability of bi-temporal DAP data for developing top height (TH) growth models for Scots pine stands. Our results indicate that DAP data can function as an alternative to traditional TH measurements used in growth modelling when corrected based on a limited sample of field-measured reference TH values. As the correction cannot be constant for each DAP dataset due to the different parameters during data acquisition, we propose a straightforward method for the bias correction of DAP-derived TH estimates. By undertaking iterative random sampling, we were able to find the minimum number of reference measurements needed to calculate the TH correction in order to achieve the desired accuracy of the TH estimations based on DAP. Here, we used ALS data as the reference data; however, the ALS measurements can be replaced by any other reliable source of TH values. The presented method for determining TH can be used not only for site index and forest growth modelling but also in forest inventories.

Rivaroxaban versus vitamin K antagonist treatment on the progression of coronary calcification: the IRIVASC-trial

Vitamin K antagonists (VKA) remain the only option of anticoagulation for people with mechanical valve replacement and due to their wider availability and lower acquisition costs, VKA’s remain widely used in low- and middle-income countries. It has been suggested that prolonged use of VKAs can increase the development of vascular and valvular calcification, though this effect has not been examined in larger randomized prospective trials. This investigator-initiated multicenter, prospective, randomized, open-label interventional trial randomized patients with baseline coronary or valvular calcification and an indication for prolonged oral anticoagulation therapy to Marcumar or Rivaroxaban. Patients were followed-up through repeat coronary computed tomographies to measure the progression of coronary and valvular calcification for up to 24 months. 192 patients were randomized between 2013 and 2018 to receive either Rivaroxaban or Marcumar and followed for up to 24 months. Coronary calcification significantly increased over time although there was no significant difference in progression between the groups after 12 and 24 months as measured by the Agatston score [360.7 (90.2; 1075.3) vs 380.4 (136.4; 1546.9) p = 0.69], the volume score [295.8 (93.0; 995.3) vs 335.5 (128.7; 1316.9) p = 0.95] and the mass score [58.5 (15.9; 172.0) vs 71.1 (24.8; 257.3) p = 0.5]. Dephosphorylated, uncarboxylated matrix Gla Protein (Dp-ucMGP) significantly decreased in the VKA group [Δ dp-uc MGP – 95.2 (− 554.1; 156.0) vs 231.3 (− 59.7; 388.1) p < 0.001]. There does not appear to be a relevant effect of vitamin K inhibition by the vitamin K antagonist marcumar upon coronary calcification.

Cost-effectiveness analysis of levonorgestrel-releasing intrauterine system (LNG-IUS) 52 mg versus other long-acting reversible contraceptives for contraception in Spain

Introduction Condoms and combined oral contraceptive pills are widely used in Spain with high failure rates. Long-Acting Reversible Contraceptive (LARC) methods offer better efficacy and adherence and reduce unintended pregnancies (UP) compared with short-acting reversible contraceptive (SARC) methods. Objective To assess the cost-effectiveness of LNG-IUS 52 mg (Mirena®) versus other LARC for contraception in Spain. Materials and Methods A Markov model with annual cycles and an eight-year time horizon was developed from the Spanish national healthcare system (NHS) perspective, considering costs for contraceptive method acquisition, health care resources (HCR) and UP. Effectiveness was based on failure and discontinuation rates. Sensitivity analyses were performed to test the model’s robustness. Results LNG-IUS 52 mg (Mirena®) resulted in lower costs and fewer UP versus LNG-IUS 13.5 mg (Jaydess®), Implant (Implanon®) and Copper IUD. LNG-IUS 52 mg (Levosert®) prevented the same UP events at a higher cost. LNG-IUS 19.5 mg (Kyleena®) was the most effective option, due to a lower discontinuation rate. Conclusions LNG-IUS 52 mg (Mirena®) is the least costly LARC, driven by lower acquisition costs and reduced HCR utilisation. Increasing LNG-IUS 52 mg (Mirena®) uptake in contraception could generate further cost savings for the Spanish NHS and reduce economic burden of UP.

Detection of Cavitation in a Centrifugal Pump-as-Turbine Using Time-Domain-Based Analysis of Vibration Signals

Pumps-as-Turbines (PATs) are increasingly used in micro-hydropower applications due to their cost competitiveness that is brought about by lower acquisition, design, operation, and maintenance costs. Despite these, limited research exists that investigates PAT failures. Notably, there is a literature gap concerning cavitation in PATs. As such, this study proposes an improvement to the deviation from the normal distribution (DND) technique to facilitate application in PAT cavitation detection. Probability density functions of vibration signals collected during operation at design speed and various cavitation states are developed and the DND computed using two approaches, i.e., the use of baseline data and the original method, for comparison purposes. Normal probability plots are presented to depict suitability of the two approaches in quantifying the DND. Results show higher deviation when using baseline data, hence, improved detection capabilities with amplification of the slope of the trend line under cavitating conditions when using the proposed DND approach. The proposed method also allows for establishing clear alarm limits for the condition monitoring of PATs in practice. Moreover, the proposed method is validated by application at various PAT operating speeds and cavitation states. The proposed method is found to be responsive, reliable, and independent from operating speed.

Management control: The acquisition cost of equipment and controls in a hospital unit

The acquisition cost of every equipment is connected to the complexity degree of the operation, leading to possible differences among the assigned controls. Variations in control practices are likely to be more complex depending on the organizations, as in the case of hospital units. The paper aimed to control a hospital unit based on the asset acquisition cost and considering contingency factors. Management control is understood as a set of activities and practices to guarantee the enforcement of management plans (Anthony &amp; Govindarajan, 2008). A single-case study qualitative approach was used and data was collected from semi-structured interviews. The object was a hospital in Brazil. The asset acquisition cost did not seem to interfere with the control practices adopted by the hospital unit. In this manner, the organization assets are recorded and controlled uniformly. In spite of a formal and structured internal control, an asset having a higher or lower acquisition cost does not directly interfere with control.

Drone-Acquired Short-Wave Infrared (SWIR) Imagery in Landscape Archaeology: An Experimental Approach

Many rocks, minerals, and soil types reflect short-wave infrared (SWIR) imagery (900–2500 nm) in distinct ways, and geologists have long relied on this property to aid in the mapping of differing surface lithologies. Although surface archaeological features including artifacts, anthrosols, or structural remains also likely reflect SWIR wavelengths of light in unique ways, archaeological applications of SWIR imagery are rare, largely due to the low spatial resolution and high acquisition costs of these data. Fortunately, a new generation of compact, drone-deployable sensors now enables the collection of ultra-high-resolution (&lt;10 cm), hyperspectral (&gt;100 bands) SWIR imagery using a consumer-grade drone, while the analysis of these complex datasets is now facilitated by powerful imagery-processing software packages. This paper presents an experimental effort to develop a methodology that would allow archaeologists to collect SWIR imagery using a drone, locate surface artifacts in the resultant data, and identify different artifact types in the imagery based on their reflectance values across the 900–1700 nm spectrum. Our results illustrate both the potential of this novel approach to exploring the archaeological record, as we successfully locate and characterize many surface artifacts in our experimental study, while also highlighting challenges in successful data collection and analysis, largely related to current limitations in sensor and drone technology. These findings show that as underlying hardware sees continued improvements in the coming years, drone-acquired SWIR imagery can become a powerful tool for the discovery, documentation, and analysis of archaeological landscapes.

What is the best first choice oral drug therapy for OAB?

The management of overactive bladder (OAB) involves lifestyle changes and conservative measures in the first instance with the use of liquid/dietary advice, weight loss, and bladder training. Thereafter oral pharmacotherapy is instigated in symptomatic patients. Antimuscarinics and beta 3 agonists form the main classes of drug therapy in this field. Views on what is the best first line OAB treatment is changing based on recent evidence and adverse event profiles of these medications. At the ICI-RS meeting 2023, Bristol, UKthis topic was discussed and debated as a proposal. The following article summarizes the concepts presented that day as well as the interactive discussion that took place thereafter. OAB guidelines are moving in many circumstances to an either antimuscarinic or beta 3 agonist approach based on patient factors. Several studies have raised concerns on the long-term impact of antimuscarinics, in relation to cognition, dementia, cardiovascular events, and mortality all related to antimuscarinic load. Neither antimuscarinics nor beta 3 agonists have good persistence and adherence rates in the medium to long term. Several barriers also exist to prescribing including guidelines recommending utilizing drugs with the lowest acquisition cost and "step therapy." A newer approach to managing OAB is personalized therapy in view of the many possible etiological factors and phenotypes. These concepts are highlighted in this article. Current oral pharmacotherapy in managing OAB is limited by adverse events, adherence and persistence problems. Both antimuscarinics and beta 3 agonists are efficacious but most clinical trials demonstrate significant placebo effects in this field. Personalizing treatment to the individual seems a logical approach to OAB. There is a need for better treatments and further studies are required of existing treatments with high quality longer term outcomes.

Transanal Endoscopic Microsurgery (TEM) is a surgical option to preserve fecal continence in selected low rectal cancers

Despite its existence for more than 40 years, the TEM method has not become widespread. The main reasons are the high acquisition costs, the sophisticated technology and alternative procedures (especially radical resection procedures), which provide greater oncological safety. However, avoiding major abdominal surgery with the creation of a stoma and higher complication rates can outweigh the higher risk of recurrence for some patients. We examined the results using V-TEM with reduced acquisition costs in the resection of adenomas and carcinomas and discussed its importance by literature . From 2003 to 2019, 154 patients with 170 findings were operated by V-TEM technology. Data on the operation and follow-up were collected and analyzed retrospectively. The median age was 67 years, 89 patients were male and 65 female. V-TEM was performed on 79 carcinomas, 77 adenomas and 14 other findings. The complication rate was 21.2%. R0 resection was achieved in 78.8%. The adenoma recurrence rate was 7.3%, the overall recurrence rate for carcinomas 11.9%, local recurrences were observed in 6.8%. The disease-specific survival is 100% at 5 years and 94.2% at ten years. The successful use of TEM in adenomas and early carcinomas is undisputed. When treating carcinomas from a T1 high risk stage using TEM, recurrence rates higher than 10% must be expected. Better results can be achieved with radical procedures, this is why they are considered the therapy of choice in these cases. However, there are no differences in terms of survival rates and TEM offers proven better postoperative quality of life. In particular, the combination of neoadjuvant procedures with TEM delivered promising results in more advanced stages. Further studies on TEM and the possibility of lower acquisition costs through modification to V-TEM could make the method more popular in the future.

Trends in navigation-handheld systems

Navigation-assisted surgical procedures in orthopedics and trauma surgery have become increasingly widespread over the last 20years. In addition to applications in spinal surgery, they are primarily available for knee and hip endoprosthetics. On the one hand, computer-assisted procedures have been increasingly expanded with robotic assistance systems in recent years, and on the other hand, so-called handheld navigation systems have been developed, which enable specialized use directly in the operating field at lower acquisition costs. The aim of this overview is to describe current handheld systems and to present the respective technical principles and the available scientific results. Three handheld systems for TKA use, two for THA use and one system to support pedicle screw placement on the spine are presented.

Prevalence of the use of integrative and complementary practices and chronic diseases: 2019 National Health Survey

The study sought to investigate the association between having a chronic disease or condition and the prevalence of having recourse to Integrative and Complementary Practices (ICP) among the Brazilian adult population. Chronic diseases are a serious public health issue and there are limitations of Western medicine to offer effective answers. Thus, the demand for ICP has increased as they constitute a humanized treatment option, with low cost and ease of acquisition. A cross-sectional population-based study was carried out using data from the 2019 National Health Survey. The prevalence of ICP use was estimated by categories of the other variables (presence or absence of chronic conditions) and prevalence ratios (PR) were adjusted for sociodemographic variables. The prevalence of the use of a given ICP, in the last 12 months, by the adult Brazilian population (18 years of age and over) was 5.5% (95%CI: 5.2%-5.8%), and adults with a chronic condition had a higher prevalence of use (PR: 2.11; 95%CI: 1.89-2.36), even after adjusting for sociodemographic characteristics. Stroke, asthma, arthritis, work-related musculoskeletal disorders, depression and other mental illnesses, chronic obstructive pulmonary disease, cancer and heart disease such as hypertension were associated with a higher prevalence of ICP use.

CycleGAN-Based SAR-Optical Image Fusion for Target Recognition

The efficiency and accuracy of target recognition in synthetic aperture radar (SAR) imagery have seen significant progress lately, stemming from the encouraging advancements of automatic target recognition (ATR) technology based on deep learning. However, the development of a deep learning-based SAR ATR algorithm still faces two critical challenges: the difficulty of feature extraction caused by the unique nature of SAR imagery and the scarcity of datasets caused by the high acquisition cost. Due to its desirable image nature and extremely low acquisition cost, the simulated optical target imagery obtained through computer simulation is considered a valuable complement to SAR imagery. In this study, a CycleGAN-based SAR and simulated optical image fusion network (SOIF-CycleGAN) is designed and demonstrated to mitigate the adverse effects of both challenges simultaneously through SAR-optical image bidirectional translation. SAR-to-optical (S2O) image translation produces artificial optical images that are high-quality and rich in details, which are used as supplementary information for SAR images to assist ATR. Conversely, optical-to-SAR (O2S) image translation generates pattern-rich artificial SAR images and provides additional training data for SAR ATR algorithms. Meanwhile, a new dataset of SAR-optical image pairs containing eight different types of aircraft has been created for training and testing SOIF-CycleGAN. By combining image-quality assessment (IQA) methods and human vision, the evaluation verified that the proposed network possesses exceptional bidirectional translation capability. Finally, the results of the S2O and O2S image translations are simultaneously integrated into a SAR ATR network, resulting in an overall accuracy improvement of 6.33%. This demonstrates the effectiveness of SAR-optical image fusion in enhancing the performance of SAR ATR.

Automatic detection of crop lodging from multitemporal satellite data based on the isolation forest algorithm

Rapid identification of crop lodging has implications for optimizing disaster prevention and mitigation measures. This study proposes a sequentially integrated algorithm for crop lodging identification, which first automatically extracts lodged and non-lodged samples based on the isolation forest algorithm from the screened features dataset and then uses a supervised classifier for lodging identification. Taking the crop lodging disaster caused by the super typhoon “Maysak” in Bohetai Township as an example, we calculated 162 feature indices from Sentinel-1 and Sentinel-2 satellite data pre- and post-disaster and screened the optimal features. Then, the abnormal scores of the cultivated-land pixels were calculated using the isolation forest algorithm. After that, we calculated the coefficient of variation (CV) of the abnormal scores of each group, extracted the lodged and non-lodged samples based on the cumulative CV contribution rate, and input samples into three supervised classifiers (random forest, maximum likelihood, and support vector machine) to identify lodged crop pixels. The results showed that feature screening increased the identification accuracy of crop lodging by more than 10% and difference features of short-wave infrared (SWIR) and red edge bands contributed significantly to the identification. The accuracy of crop lodging automatic identification was verified using samples obtained from visual interpretation and digitization of UAV images as reference data and the overall accuracy reached 78%. The proposed method can simultaneously recognize lodging of different crop types without the need to select lodged samples and extract lodged ranges for each crop. With low data acquisition costs and high automation, the proposed method has promising applications in agricultural disaster emergency management and agricultural insurance loss assessment.

Gel Biopolymer Electrolytes Based on Saline Water and Seaweed to Support the Large-Scale Production of Sustainable Supercapacitors.

Climate change and the demand for clean energy have challenged scientists worldwide to produce/store more energy to reduce carbon emissions. This work proposes a conductive gel biopolymer electrolyte to support the sustainable development of high-power aqueous supercapacitors. The gel uses saline water and seaweed as sustainable resources. Herein, a biopolymer agar-agar, extracted from red algae, is modified to increase gel viscosity up to 17-fold. This occurs due to alkaline treatment and an increase in the concentration of the agar-agar biopolymer, resulting in a strengthened gel with cohesive superfibres. The thermal degradation and agar modification mechanisms are explored. The electrolyte is applied to manufacture sustainable and flexible supercapacitors with satisfactory energy density (0.764 Wh kg-1 ) and power density (230 W kg-1 ). As an electrolyte, the aqueous gel promotes a long device cycle life (3500 cycles) for 1 A g-1 , showing good transport properties and low cost of acquisition and enabling the supercapacitor to be manufactured outside a glove box. These features decrease the cost of production and favor scale-up. To this end, this work provides eco-friendly electrolytes for the next generation of flexible energy storage devices.

Lowering acquisition costs with a commission cap? Evidence from the German private health insurance market

AbstractWhen consumers are neither particularly financially literate nor price sensitive, insurers have a strong incentive to pay high commissions to intermediaries for profitable new business. As a part of cost reduction regulation in the German private substitutive health insurance market, a commission cap and a minimum cancelation liability period for insurance intermediaries were introduced in 2012. Despite the fact that the commission cap lowered commissions paid to intermediaries, we provide evidence that the reform was only partly effective, as it led to a decrease in reshuffling of new business in the substitutive market, but did not significantly reduce total acquisition costs of health insurers. Our findings confirm that cost regulation is tricky and can be easily circumvented by insurers, as commission payments are only a part of total acquisition costs.

Tensile Behaviour of PLA Parts Manufactured by FFF with Defects in the Interlayer Filament Bonding and its Application in Product Design

Additive Manufacturing (AM) has been one of the technologies that has been booming in recent years. Its main advantages are the versatility in the manufacture of parts, the ability to print limited series and its low acquisition cost, among others. Among these technologies, one of the most widely used by engineering and product design teams is Fused Filament Fabrication (FFF). PLA being one of the materials most employed for FFF. Likewise, for a proper shaping of this material and process, it is necessary to establish several parameters to define the quality and properties of the designed part. In this context, a comparison of two groups of pieces has been carried out. Whereas the first group exhibits a correct process parameters and an adequate calibration of the printing bed; the second, has not any bonding between layers or bonding of beads of the same layer, due to an incorrect establishment of the initial parameters. In order to compare these groups, a study of the internal structure was carried out by X-Ray CT along with a characterization of their tensile mechanical properties. Results show a similar maximum stress for both groups, but a drastic reduction of the plastic area in the parts with defects. The quantification and comparison of the mechanical properties of both tests might provide a rejection criterion for parts that work in tension and present defects similar to those studied for engineering teams in product design.

An approach of using social media data to detect the real time spatio-temporal variations of urban waterlogging

Urban waterlogging has occurred frequently in recent years due to the impact of climate change and human activities. Real-time waterlogging information is crucial for disaster emergency management, but how to quickly obtain such information remains challenging. Social media data has been widely used to derive damage information because of its high real-time response, low acquisition cost, and high content integration. In this study, we propose an approach to extract real-time waterlogging points from social media data (Sina Weibo). First, social media data is obtained through web crawler technology; Then, de-duplication and de-noising methods are used to filter the data; Finally, a waterlogging point extraction method based on deep learning BERT-BiLSTM-CRF model is proposed to extract waterlogging points. Taking the “7.20” rainstorm in Zhengzhou as an example, there was a rapid increase in the number of social media data during urban waterlogging. Social media data is highly sensitive to urban waterlogging disasters caused by extreme rainstorms. On the day with the heaviest rainfall (July 20), the number of Weibo waterlogging points (331) in the central city was 267 more than the official waterlogging points (64). There were many more Weibo-derived waterlogging points than the real-time official published waterlogging points. The waterlogging points obtained by this approach covered the official published real-time waterlogging points accounted for no less than 82% and they were mostly located around roads, especially in low-lying areas. In general, we demonstrate the feasibility and accuracy of social media data on rapid detection of real-time spatiotemporal variations of waterlogging caused by extreme rainstorms. Urban waterlogging disaster information extracted from social media data can rapidly reflect the real-time spatiotemporal variations of urban waterlogging disasters, and can effectively cover and supplement data reported by government agencies, and can provide data support for urban waterlogging disaster prevention.

Green Biocidal Nanotechnology Use for Urban Stone-Built Heritage—Case Study from Oradea, Romania

Heritage buildings clad with natural rock endure over time destruction caused by weathering mechanisms, pollution from urban areas, biodeterioration due to organisms, microorganisms, and also the anthropic factor. On the surface of the limestone samples taken from the ornamental natural rock with which the outside of Markovits-Mathéser house, Oradea, Romania, is clad, two species of fungi were inoculated in the laboratory: Aspergillus spp. and Cladosporium spp. Wollastonite was then applied, and from the imaging analysis (SEM), the inhibition of fungi by it is clearly observed (48 h after its application), which was also confirmed using the image segmentation method. It was also noted that the hydrophilicity of the aqueous suspension of wollastonite resulted in the absorption of water in the substrate, which in turn resulted in the drying out and surface breakage of the specimens. X-ray diffraction analysis showed the presence of the two phases (calcite and quartz) as in the starting sample, and also an additional phase assigned to wollastonite in the later phase of the experiment. An amorphous component, due to the applied gel composition, was also reported. This research highlights the fact that there are good premises for aqueous suspension of wollastonite to have a biocidal character for Aspegillus spp. and Cladosporium spp., when applied on natural stone used in the construction of heritage buildings located in temperate climates; due to its easy application, green and ecofriendly properties, and also low cost of acquisition and application.

Cost-effectiveness analysis of baricitinib versus dupilumab for moderate to severe atopic dermatitis: an Italian healthcare system perspective

AimsTo assess, within the Italian healthcare system, the cost-effectiveness of baricitinib versus dupilumab, both in combination with topical corticosteroids (TCS), in adults with moderate to severe atopic dermatitis (AD) who are eligible for but have failed, have contraindications to, or cannot tolerate ciclosporin.Materials and methodsUsing the perspective of the Italian healthcare payer, direct medical costs associated with each intervention were estimated over a lifetime horizon. A Markov cohort model utilized the proportions of patients with ≥75% improvement Eczema Area and Severity Index obtained from clinical trials. Health outcomes were evaluated in quality-adjusted life years (QALYs) to assess the cost effectiveness of baricitinib against a willingness-to-pay threshold of €35,000 per QALY gained.ResultsIn the base case, with secondary censoring applied, patients treated with dupilumab or baricitinib, in combination with TCS, accumulated total costs of €135,780 or €129,586, and total QALYs of 18.172 or 18.133, respectively. The incremental cost-effectiveness ratio of dupilumab versus baricitinib was estimated at €160,905/QALY.LimitationsCore assumptions were needed to extrapolate available short-term clinical trial data to lifelong data, adding uncertainty. Benefits of baricitinib seen in clinical trials and not assessed in dupilumab clinical trials were not included. Discontinuation rates for each treatment were derived from different sources potentially introducing bias. Results may not be generalizable to other populations.ConclusionsThis cost-effectiveness analysis shows that, from the Italian healthcare payer perspective, in the treatment of patients with moderate to severe AD who have experienced failure on, are intolerant to, or have contraindication to ciclosporin, dupilumab cannot be considered cost-effective when compared with baricitinib. Given its oral administration, favorable risk/benefit profile and lower acquisition cost compared with dupilumab, baricitinib may offer a valuable, cost-effective treatment option—after failure on conventional systemic agents—for patients with moderate to severe AD in Italy.

Hierarchical classification for acoustic scenes using deep learning

Acoustic Scene Classification (ASC) aims to obtain the sound environment by analyzing audio signals. Due to the low complexity and acquisition cost of audio signals, ASC has enormous potential in various applications, such as audio-based surveillance, smart cities/homes, and robotics. Recently, various methods have been proposed for ASC and achieved good performance. However, when they are used to address complex ASC problems, most of them suffer from the low-performance problem. In this paper, we propose to use hierarchical classification methods to replace the conventional flat approach in ASC applications, which utilizes the class hierarchy to optimize classification performance. In particular, we investigate the ASC problem under the framework of hierarchical classification. Firstly, to improve classification performance, three hierarchical classification methods introducing the class hierarchy of acoustic scenes are proposed for ASC. Moreover, to fully utilize the class hierarchy, a hybrid hierarchical classification method, and an optimal late fusion-based hierarchical method are proposed, which are based on the flexibility and simplification of hierarchical classification. The experiments demonstrate the efficacy of hierarchical ASC systems for performance improvement, and the best system achieves an accuracy of 78.86% on the DCASE 2020 Task1A dataset, resulting in accuracy gains of 24.76% and 8.52% absolute over the DCASE 2020 Task 1A baseline and the conventional non-hierarchical method, respectively.