Abstract:This paper studies representation of rigid combination of a directed line and a reference point on it (here referred to as a "point-line") using dual quaternions. The geometric problem of rational ruled surface design is viewed as the kinematic problem of rational point-line motion design. By using the screw theory in kinematics, mappings from the spaces of lines and point-lines in Euclidean three-dimensional space into the hyperplanes in dual quaternion space are constructed, respectively. The problem of rati… Show more
“…The RTS/CTS handshake protocol is an optional scheme on top of the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol [14] for a four-way handshake mode (RTS-CTS-DATA-ACK) [15]. It is proposed to solve the hidden terminal [11] problem, which refers to a node that is outside the coverage of the sending node but in the coverage of the receiving node, as illustrated in Figure 1.…”
Section: Overview Of the Rts/cts Handshake Protocolmentioning
TCP protocol has good performance on the Internet, but its performance is significantly reduced when it is applied to Marine Internet (MI). How to improve the performance of TCP protocol in Marine Internet has become an important research topic. In this paper, an improved Semi-TCP is adopted for Marine Internet, and the implementation scheme of Semi-TCP congestion control is introduced. The exposed terminal problem and congestion control problem of high load networks are analyzed in detail. By using a timer, the congestion control algorithm is improved. Performance analysis and comparison of TCP-Lite, Semi-TCP-RTS, and improved Semi-TCP (Semi-TCP-RTS-V2) are carried out on Exata simulation platform, and the experimental results show that Semi-TCP-RTS-V2 has better transmission performance in ship ad hoc networks.
“…The RTS/CTS handshake protocol is an optional scheme on top of the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol [14] for a four-way handshake mode (RTS-CTS-DATA-ACK) [15]. It is proposed to solve the hidden terminal [11] problem, which refers to a node that is outside the coverage of the sending node but in the coverage of the receiving node, as illustrated in Figure 1.…”
Section: Overview Of the Rts/cts Handshake Protocolmentioning
TCP protocol has good performance on the Internet, but its performance is significantly reduced when it is applied to Marine Internet (MI). How to improve the performance of TCP protocol in Marine Internet has become an important research topic. In this paper, an improved Semi-TCP is adopted for Marine Internet, and the implementation scheme of Semi-TCP congestion control is introduced. The exposed terminal problem and congestion control problem of high load networks are analyzed in detail. By using a timer, the congestion control algorithm is improved. Performance analysis and comparison of TCP-Lite, Semi-TCP-RTS, and improved Semi-TCP (Semi-TCP-RTS-V2) are carried out on Exata simulation platform, and the experimental results show that Semi-TCP-RTS-V2 has better transmission performance in ship ad hoc networks.
“…Pottmann et al explored offsets of rational ruled surfaces [12]. Furthermore, the geometry of ruled surfaces plays a crucial role in the study of kinematic and positional mechanisms, as demonstrated by Kühnel, Abdel Baky, Ekici and Çöken, Zhang, Ünlütürk et al and Ekici et al [13,14,15,16,17,18]. Similar to the fundamental theorem of curves, which facilitates the determination of a curve based on curvature and torsion, a similar structure can be recognized in the field of reconstruction of a ruled surface.…”
In this paper, we first provide a summary of certain results related to the differential geometry of ruled surfaces. Next, we introduce the signature curve for ruled surfaces in Euclidean three-space. Additionally, we present a straightforward algorithm for the reconstruction of a ruled surface, which is both efficient and entirely local, requiring only the initial motion direction and starting point. Finally, we illustrate the efficiency and accuracy of the algorithm through several examples.
Bu makalede, öncelikle regle yüzeylerin diferesiyel geometrisi ile ilgili bazı sonuçların bir özetini sunuyoruz. Daha sonra, Öklid üç uzayında regle yüzeyler için işaret eğrisini tanıtıyoruz. Ek olarak, bir regle yüzeyin yeniden yapılandırılması için hem verimli hem de tamamen yerel olan, yalnızca ilk hareket yönü ve başlangıç noktası gerektiren basit bir algoritma sunuyoruz. Son olarak, algoritmanın verimliliğini ve doğruluğunu birkaç örnekle gösteriyoruz.
“…The wasp Pachyneuron aphidis Bouché (Hymenoptera: Pteromalidae) is a common hyperparasitoid of A. gifuensis and is the dominant hyperparasitoid of A. gifuensis in Yunnan province in China (Wei et al, 2003), where hyperparasitism reached 65% in tobacco (Chai, Kuang, & Zhu, 2013). Detailed investigations have been carried out on this hyperparasitoid's biology (Chai, Deng, & Wu, 2005;Chai, Kuang, & Zhu, 2008;Ming, Gu, Wei, & Zhang, 2005;Zhao, Zhu, Wu, & Gao, 2009), population dynamics (Chai et al, 2013) and olfactory responses (Zhang et al, 2012). The phototactic behaviour of the host aphid (Fu et al 2009) and the primary parasitoid (Chen, Kuang, Zhou, & Liu, 2012) have previously been examined but the phototactic behaviour of the hyperparasitoid P. aphidis has not been investigated.…”
We investigated the spectral sensitivity and response to light intensity of Pachyneuron aphidis (Hymenoptera: Pteromalidae), which is a common hyperparasitoid of Aphidius gifuensis (Hymenoptera: Braconidae), a key natural enemy of the green peach aphid, Myzus persicae (Hemiptera: Aphididae). To do so, we used 15 monochromatic lights (emitting various specific wavelengths from 340 to 649 nm) and white light. P. aphidis adults are diurnal insects that show a positive phototaxis to a broad spectrum of light. Significant differences were found between sexes in the phototactic responses of P. aphidis to different monochromatic lights. Female P. aphidis showed four peaks of sensitivity at 380, 450, 504 and 589 nm. Male P. aphidis show two peaks of sensitivity, one at 450 nm and second at 628 nm. P. aphidis adults showed an increased phototactic response at low intensities and a decreased phototactic response at high intensities for both UV light and blue light. This experiment will help provide a scientific basis for the development of colour traps for insect pest management.
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