Journal of Bionic Engineering

Locomotion of Gymnarchus Niloticus: Experiment and Kinematics

Li Fei, Hu Tian-jiang, Wang Guang-ming, Shen Lin-cheng

J4. 2005, 2 (3): 115-121. DOI:

Abstract ( 1301 )

PDF

In addition to forward undulatory swimming, Gymnarchus niloticus can swim via undulations of the dorsal fin while the body axis remains straight; furthermore, it swims forward and backward in a similar way, which indicates that the undulation of the dorsal fin can simultaneously provide bidirectional propulsive and maneuvering forces with the help of the tail fin. A high-resolution Charge-Coupled Device (CCD) imaging camera system is used to record kinematics of steady swimming as well as maneuvering in G.niloticus. Based on experimental data, this paper discusses the kinematics (cruising speed, wave speed, cycle frequency, amplitude, lateral displacement) of forward as well as backward swimming and maneuvering. 
　　During forward swimming, the propulsive force is generated mainly by undulations of the dorsal fin while the body axis remains straight. The kinematic parameters (wave speed, wavelength, cycle frequency, amplitude) have statistically significant correlations with cruising speed. In addition, the yaw at the head is minimal during steady swimming. From experimental data, the maximal lateral displacement of head is not more than 1% of the body length, while the maximal lateral displacement of the whole body is not more than 5% of the body length. Another important feature is that G.niloticus swims backwards using an undulatory mechanism that resembles the forward undulatory swimming mechanism. In backward swimming, the increase of lateral displacement of the head is comparatively significant; the amplitude profiles of the propulsive wave along the dorsal fin are significantly different from those in forward swimming. When G.niloticus does fast maneuvering, its body is first bent into either a C shape or an S shape, then it is rapidly unwound in a travelling wave fashion. It rarely maneuvers without the help of the tail fin and body bending.bending.

Related Articles | Metrics

The Bionic Anticipation of Natural Disasters

Helmut Tributsch

J4. 2005, 2 (3): 123-144. DOI:

Abstract ( 1171 )

PDF

After major natural disasters, such as the recent earthquake-tsunami event in South Asia, reports appear about the mysterious ability of animals to anticipate and to escape the impending danger. This is an opportunity to recall the long history of this phenomenon in the traditions of different civilizations, to evaluate Chinese efforts, 30-40 years ago, to use this phenomenon for earthquake prediction, and to judge its state of acceptance in modern science. An effort is made to introduce this phenomenon as a research field of modern bionics. The timing is favorable since, increasingly, infrared thermal anomalies, monitored from satellite, suggesting litho-atmospheric processes, are found to precede earthquakes. They were unexpected by seismologists and are here suggested to essentially reflect the energy conversion patterns responsible for the signals monitored by animals. The aim is to learn from animals in the long term how natural disasters can better be anticipated, and how simple technical warning systems can be developed. Some challenges are analyzed. One is interpretation of the nature of energy release prior to the main earthquake disaster resulting in “macro-anomaly” precursors, another is better to understand the effect on animal senses. The role of non-linear cooperative phenomena including tsunami-type waves is emphasized.

Related Articles | Metrics

A Computational Model of Soil Adhesion and Resistance for a Non-smooth Bulldozing Plate

Shi Wei-ping ^1,2, Ren Lu-quan ¹, Tian Li-mei ¹

J4. 2005, 2 (3): 145-150. DOI:

Abstract ( 1381 )

PDF

Adhesive forces exist between soil and the surfaces of soil-engaging components; they increase working resistance and energy consumption. This paper tries to find an approach to reduce the adhesion and resistance of bulldozing plate. A simplified mechanical model of adhesion and resistance between soil and a non-smooth bulldozing plate is proposed. The interaction force between moist soil and a non-smooth bulldozing plate is analyzed. The pressure and friction distribution on the bulldozing plate are computed, and the anti-adhesive effect of a corrugated bulldozing plate is simulated numerically. Numerical results show that the wavy bulldozing plate achieves an effective drag reduction in moist soil. The optimal wavy shape of the corrugated bulldozing plate with the minimal resistance is designed. The basic principle of reducing soil adhesion of the non-smooth surface is discovered.

Related Articles | Metrics

The Modulation and Control of the Gecko's Foot Movement

Guo Ce¹, Dai Zhen-dong¹, Ji Ai-hong¹, Wang Wei-ying¹, Sun Jiu-rong²

J4. 2005, 2 (3): 151-156. DOI:

Abstract ( 1210 )

PDF

The modulation and control of gecko's foot movements were studied electrophysiologically in order to design the motor control system of a gecko-mimic robot. In this study (1) the anatomy of the peripheral nerves controlling the gecko's foot movements was determined; (2) the relationship between the limb nerves of the gecko and its foot motor patterns was studied; (3) the afferent impulses of the nerves evoked by rubbing the gecko's toes and palm were recorded; (4) copying the natural patterns of movement of the gecko's foot (abduction, adduction, flexion, and revolution) and its limb nerve modulation and control mechanism, the nerves were stimulated under computer control, and the results recorded by CCD. Results suggest that gecko's foot movements can be successfully controlled by artificial electrical signals.

Related Articles | Metrics

A Study on Protein Residue Contacts Prediction by Recurrent Neural Network

Liu Gui-xia, Zhu Yuan-xian, Zhou Wen-gang, Huang Yan-xin, Zhou Chun-guang, Wang Rong-xing

J4. 2005, 2 (3): 157-160. DOI:

Abstract ( 1195 )

PDF

A new method was described for using a recurrent neural network with bias units to predict contact maps in proteins. The main inputs to the neural network include residues pairwise, residue classification according to hydrophobicity, polar, acidic, basic and secondary structure information and residue separation between two residues. In our work, a dataset was used which was composed of 53 globulin proteins of known 3D structure. An average predictive accuracy of 0.29 was obtained. Our results demonstrate the viability of the approach for predicting contact maps.

Related Articles | Metrics

Selected Natural Materials in History

Julian F. V. Vincent

J4. 2005, 2 (3): 161-176. DOI:

Abstract ( 962 )

PDF

Related Articles | Metrics

Quick Search Adv. Search