Robotic Models for Studying Undulatory Locomotion in Fishes

2011 ◽  
Vol 45 (4) ◽  
pp. 41-55 ◽  
Author(s):  
George V. Lauder ◽  
Jeanette Lim ◽  
Ryan Shelton ◽  
Chuck Witt ◽  
Erik Anderson ◽  
...  
Keyword(s):  
Three Dimensions ◽  
Head Region ◽  
Cost Of Transport ◽  
Great Progress ◽  
Dead Fish ◽  
Undulatory Locomotion ◽  
The Cost ◽  
Flapping Foils ◽  
Flexible Foils ◽  
Made In

AbstractMany fish swim using body undulations to generate thrust and maneuver in three dimensions. The pattern of body bending during steady rectilinear locomotion has similar general characteristics in many fishes and involves a wave of increasing amplitude passing from the head region toward the tail. While great progress has been made in understanding the mechanics of undulatory propulsion in fishes, the inability to control and precisely alter individual parameters such as oscillation frequency, body shape, and body stiffness, and the difficulty of measuring forces on freely swimming fishes have greatly hampered our ability to understand the fundamental mechanics of the undulatory mode of locomotion in aquatic systems. In this paper, we present the use of a robotic flapping foil apparatus that allows these parameters to be individually altered and forces measured on self-propelling flapping flexible foils that produce a wave-like motion very similar to that of freely swimming fishes. We use this robotic device to explore the effects of changing swimming speed, foil length, and foil-trailing edge shape on locomotor hydrodynamics, the cost of transport, and the shape of the undulating foil during locomotion. We also examine the passive swimming capabilities of a freshly dead fish body. Finally, we model fin-fin interactions in fishes using dual-flapping foils and show that thrust can be enhanced under correct conditions of foil phasing and spacing as a result of the downstream foil making use of vortical energy released by the upstream foil.

scholarly journals The performance of a flapping foil for a self-propelled fishlike body

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Damiano Paniccia ◽  
Luca Padovani ◽  
Giorgio Graziani ◽  
Renzo Piva
Keyword(s):  
Swimming Performance ◽  
Real Life ◽  
Minimum Cost ◽  
The Body ◽  
Cost Of Transport ◽  
Locomotion Speed ◽  
Optimal Efficiency ◽  
The One ◽  
The Cost ◽  
Flapping Foils

AbstractSeveral fish species propel by oscillating the tail, while the remaining part of the body essentially contributes to the overall drag. Since in this case thrust and drag are in a way separable, most attention was focused on the study of propulsive efficiency for flapping foils under a prescribed stream. We claim here that the swimming performance should be evaluated, as for undulating fish whose drag and thrust are severely entangled, by turning to self-propelled locomotion to find the proper speed and the cost of transport for a given fishlike body. As a major finding, the minimum value of this quantity corresponds to a locomotion speed in a range markedly different from the one associated with the optimal efficiency of the propulsor. A large value of the feathering parameter characterizes the minimum cost of transport while the optimal efficiency is related to a large effective angle of attack. We adopt here a simple two-dimensional model for both inviscid and viscous flows to proof the above statements in the case of self-propelled axial swimming. We believe that such an easy approach gives a way for a direct extension to fully free swimming and to real-life configurations.

scholarly journals Problems and Countermeasures in the Budget Cost Control of Decoration Engineering

2021 ◽  
Vol 248 ◽  
pp. 03026
Author(s):  
Yujia
Keyword(s):  
Cost Control ◽  
Rapid Development ◽  
Urgent Problem ◽  
Project Cost ◽  
Budget Analysis ◽  
Budget Control ◽  
Great Progress ◽  
The Cost ◽  
Made In ◽  
China’S Economy

With the rapid development of China's economy and technology, great progress has been made in all fields. Especially in the field of decoration engineering, great breakthroughs have also been made. The strength of enterprises continues to increase, and the gap between enterprises continues to narrow. In this context, how to strengthen the cost control of decoration enterprises and continuously improve their own strength has become an urgent problem. Based on this, this article carried out the budget analysis of the decoration project and analyzed the problems existing in the enterprise cost budget control. Finally, this paper proposes a series of measures such as unifying the cost budget specifications, continuously improving the project cost budget control system, and strengthening the project cost budget monitoring.

scholarly journals Pathogenesis and Potential Therapeutic Targets for Triple-Negative Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2978
Author(s):  
Chia-Jung Li ◽  
Yen-Dun Tony Tzeng ◽  
Yi-Han Chiu ◽  
Hung-Yu Lin ◽  
Ming-Feng Hou ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Targeted Therapy ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
High Efficiency ◽  
Early Recurrence ◽  
New Developments ◽  
Great Progress ◽  
Low Toxicity ◽  
Made In

Triple negative breast cancer (TNBC) is a heterogeneous tumor characterized by early recurrence, high invasion, and poor prognosis. Currently, its treatment includes chemotherapy, which shows a suboptimal efficacy. However, with the increasing studies on TNBC subtypes and tumor molecular biology, great progress has been made in targeted therapy for TNBC. The new developments in the treatment of breast cancer include targeted therapy, which has the advantages of accurate positioning, high efficiency, and low toxicity, as compared to surgery, radiotherapy, and chemotherapy. Given its importance as cancer treatment, we review the latest research on the subtypes of TNBC and relevant targeted therapies.

Rhodium-Catalyzed, Phosphorus(III)-Directed Hydroarylation of Internal Alkynes: Facile and Efficient Access to New Phosphine Ligands

Synlett ◽  
2020 ◽  
Author(s):  
Minyan Wang ◽  
Zhuangzhi Shi ◽  
Huanhuan Luo ◽  
Dawei Wang
Keyword(s):  
High Selectivity ◽  
Enantiomeric Excess ◽  
Phosphine Ligands ◽  
Rapid Construction ◽  
Efficient Access ◽  
Internal Alkynes ◽  
Great Progress ◽  
Chiral Phosphine Ligands ◽  
Optimized Conditions ◽  
Made In

AbstractOrganophosphines are an important class of ligands widely used in organic chemistry. Although great progress has recently been made in the rapid construction of new phosphines through Rh- or Ru-catalyzed C–H bond functionalizations, synthetic access to more diverse phosphines remains a challenge. We describe an efficient process for the rhodium-catalyzed phosphorus(III)-directed hydroarylation of internal alkynes to generate various alkenylated and 2′,6′-dialkenylated biarylphosphines with high selectivity. A range of diverse alkynes and phosphines were effectively prepared with broad functional-group compatibility under the optimized conditions. In addition, the developed protocol can be extended to modify chiral phosphine ligands, providing enantioenriched alkenylated phosphines without erosion of the enantiomeric excess.

Progress and Prospects for the Development of Computer-Generated Actors for Military Simulation: Part 1-Introduction and Background

2003 ◽  
Vol 12 (3) ◽  
pp. 311-325 ◽  
Author(s):  
Martin R. Stytz ◽  
Sheila B. Banks
Keyword(s):  
Research Area ◽  
Background Information ◽  
Life Cycle Costs ◽  
Material Management ◽  
Reasoning System ◽  
Force Structure ◽  
The Cost ◽  
Future Work ◽  
Level Training ◽  
Made In

The development of computer-generated synthetic environments, also calleddistributed virtual environments, for military simulation relies heavily upon computer-generated actors (CGAs) to provide accurate behaviors at reasonable cost so that the synthetic environments are useful, affordable, complex, and realistic. Unfortunately, the pace of synthetic environment development and the level of desired CGA performance continue to rise at a much faster rate than CGA capability improvements. This insatiable demand for realism in CGAs for synthetic environments arises from the growing understanding of the significant role that modeling and simulation can play in a variety of venues. These uses include training, analysis, procurement decisions, mission rehearsal, doctrine development, force-level and task-level training, information assurance, cyberwarfare, force structure analysis, sustainability analysis, life cycle costs analysis, material management, infrastructure analysis, and many others. In these and other uses of military synthetic environments, computer-generated actors play a central role because they have the potential to increase the realism of the environment while also reducing the cost of operating the environment. The progress made in addressing the technical challenges that must be overcome to realize effective and realistic CGAs for military simulation environments and the technical areas that should be the focus of future work are the subject of this series of papers, which survey the technologies and progress made in the construction and use of CGAs. In this, the first installment in the series of three papers, we introduce the topic of computer-generated actors and issues related to their performance and fidelity and other background information for this research area as related to military simulation. We also discuss CGA reasoning system techniques and architectures.

scholarly journals Relations between morphology, buoyancy and energetics of requiem sharks

2016 ◽  
Vol 3 (10) ◽  
pp. 160406 ◽  
Author(s):  
Gil Iosilevskii ◽  
Yannis P. Papastamatiou
Keyword(s):  
Body Temperature ◽  
Negative Selection ◽  
Swimming Performance ◽  
Ontogenetic Changes ◽  
Cost Of Transport ◽  
Pectoral Fins ◽  
Confined Spaces ◽  
Reef Sharks ◽  
The Cost ◽  
Derivatives Of

Sharks have a distinctive shape that remained practically unchanged through hundreds of millions of years of evolution. Nonetheless, there are variations of this shape that vary between and within species. We attempt to explain these variations by examining the partial derivatives of the cost of transport of a generic shark with respect to buoyancy, span and chord of its pectoral fins, length, girth and body temperature. Our analysis predicts an intricate relation between these parameters, suggesting that ectothermic species residing in cooler temperatures must either have longer pectoral fins and/or be more buoyant in order to maintain swimming performance. It also suggests that, in general, the buoyancy must increase with size, and therefore, there must be ontogenetic changes within a species, with individuals getting more buoyant as they grow. Pelagic species seem to have near optimally sized fins (which minimize the cost of transport), but the majority of reef sharks could have reduced the cost of transport by increasing the size of their fins. The fact that they do not implies negative selection, probably owing to decreased manoeuvrability in confined spaces (e.g. foraging on a reef).

scholarly journals 110 Managing Feed Efficiency to Improve Dairy Farm Margin

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 20-20
Author(s):  
Micheal J Brouk
Keyword(s):  
Milk Production ◽  
Production Cost ◽  
Dairy Farm ◽  
Animal Reproduction ◽  
High Feed ◽  
Efficiency Factors ◽  
Feed Costs ◽  
The Cost ◽  
The Impact ◽  
Made In

Abstract Dairy farm margin has continued to be a challenge for the dairy industry. Several years of challenging milk prices with limited relief from high feed costs and increasing production cost have continued to erode the net margin of US dairy farms. As dairy producers continue to operate in a challenging economic environment, discoveries are being made in various farm efficiencies to improve farm margin. Increased management intensity on all aspects of the dairy farm is resulting in the discover of and improvement of many individual efficiency factors. Key areas of economic efficiency include feed, animal reproduction, replacement animals, labor and resource allocation. Often the answer to improved efficiency involves more than just reduced production cost, but also in the improvement of production to reduce the cost per unit of milk produced. Identifying and focusing on the important factors that can improve overall farm efficiency will enable producers to weather the economic challenges. For dairy producers, one of the complications is the biology of the dairy cow and understanding how to utilize the biology correctly for improved efficiency of milk production. Improved efficiency of milk production requires attention to details in many areas of the dairy. Identifying the correct areas of deficiencies, establishing corrective plans of action and then careful evaluation of the impact of changes are all key to the overall success of improving dairy farm margins and efficiencies.

scholarly journals ANALISIS USAHA DAN PEMASARAN GULA SEMUT DI DESA HARGOTIRTO, KECAMATAN KOKAP, KABUPATEN KOKAP

2019 ◽  
Vol 16 (1) ◽  
pp. 74
Author(s):  
Mega Nugraheni Apriza Putri ◽  
Raden Kunto Adi ◽  
Isti Khomah
Keyword(s):  
Cost Benefit ◽  
Marketing Channel ◽  
Snowball Sampling ◽  
Brown Colour ◽  
Business Analysis ◽  
Marketing Efficiency ◽  
The Cost ◽  
Benefit Cost ◽  
Descriptive Method ◽  
Made In

Gula semut adalah produk inovatif dari pengolahan nira kelapa dalam bentuk bubuk atau butiran bewarna kuning sampai cokelat. Sebanyak 433.820 kg produksi gula semut dibuat di Desa Hargotirto. Penelitian bertujuan untuk menganalisis pendapatan usaha, pola saluran pemasaran, biaya, keuntungan, marjin pemasaran, dan efisiensi pemasaran secara ekonomi masing-masing saluran pemasaran di Desa Hargotirto. Metode dasar yang digunakan adalah metode deskriptif analisis. Metode penentuan lokasi secara <em>purposive</em> di Desa Hargotirto, Kecamatan Kokap, Kabupaten Kulon Progo. Metode pengambilan responden secara random dengan teknik undian sejumlah 93 responden. Pengambilan responden saluran pemasaran dengan <em>snowball sampling</em>. Analisis data yang digunakan dalam menghitung analisis usaha dan pemasaran untuk mengetahui biaya, penerimaan, pendapatan usaha, biaya pemasaran, keuntungan pemasaran, dan marjin pemasaran. Hasil penelitian menunjukkan rata-rata penerimaan sebesar Rp51.366,22, biaya total sebesar Rp25.401,16, danrata-rata pendapatan sebesar Rp25.959,05. Terdapat tiga pola saluran pemasaran di Desa Hargotirto. Total biaya pemasaran masing-masing saluran pemasaran yaitu Rp5.845,30, Rp5.374,72, dan Rp3.407,73. Total keuntungan pemasaran masing-masing saluran pemasaran yaitu Rp7.640,39, Rp7.343,56, dan sebesar Rp9.960,95. Total marjin pemasaran pada masing-masing saluran yaitu Rp6.636,36, Rp5.000,00, dan Rp4.849,91. Nilai <em>farmer’s share</em> untuk masing-masing saluran pemasaran yaitu 72,35%, 77,99%, dan 78,20%<strong>.</strong><br /><p><strong><br /></strong></p><p><em>Crystal coconut sugar is an innovative product from processing coconut palm in the powder or granular form that have</em><em> </em><em>a</em><em> </em><em>yellow to brown colour.</em><em> </em><em>A total of 433,820 kg of crystal coconut sugar made in Hargotirto Village.</em><em> </em><em>The aim of this research is to </em><em>analyse</em><em> the cost, revenue, income, marketing cost, benefit cost</em><em>, </em><em>marginal marketing, and marketing efficiency economically </em><em>in</em><em> Hargotiro Village</em><em>.</em><em> </em><em>The method applied is the descriptive method. The sample area is chosen on purposive sampling. The sample of producent is taken by random and take 93 sample. The method of take snowball sampling marketing channel respondents. The data analysis used is the cost analysis, revenue, income, marketing cost, benefit cost, and marginal marketing. The result of the research business analysis shows that are total rate revenue of crystal coconut sugar Rp51</em><em>,</em><em>360</em><em>.</em><em>22. </em><em>T</em><em>hat are three pattern of marketing channel of crystal coconut sugarin Hargotirto Village</em><em>.</em><em> Total benefit for </em><em>each marketing channel is</em><em> Rp7</em><em>,</em><em>640</em><em>.</em><em>39, Rp7</em><em>,</em><em>343</em><em>.</em><em>56, and Rp9</em><em>,</em><em>960</em><em>.</em><em>95. Total Marginal marketing for </em><em>each marketing channel is</em><em> Rp6.636,36, Rp5.000,00, and Rp4.840,91. Farmer’s share for each marketing channel is 72,35%, 77,99%, and 78,20%.</em></p><p><strong><br /></strong></p><strong></strong><em></em>

New Evolutionary Algorithm Based on 2-Opt Local Search to Solve the Vehicle Routing Problem with Private Fleet and Common Carrier

2012 ◽  
pp. 125-148
Author(s):  
Jalel Euchi ◽  
Habib Chabchoub ◽  
Adnan Yassine
Keyword(s):  
Local Search ◽  
Evolutionary Algorithm ◽  
Vehicle Routing ◽  
Cost Savings ◽  
Alternative Mode ◽  
Cost Of Transport ◽  
Routing Problem ◽  
The Cost ◽  
Specific Assignment ◽  
Selection Of

Mismanagement of routing and deliveries between sites of the same company or toward external sites leads to consequences in the cost of transport. When shipping alternatives exist, the selection of the appropriate shipping alternative (mode) for each shipment may result in significant cost savings. In this paper, the authors examine a class of vehicle routing in which a fixed internal fleet is available at the warehouse in the presence of an external transporter. The authors describe hybrid Iterated Density Estimation Evolutionary Algorithm with 2-opt local search to determine the specific assignment of each tour to a private vehicle (internal fleet) or an outside carrier (external fleet). Experimental results show that this method is effective, allowing the discovery of new best solutions for well-known benchmarks.

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