A Comparative Study of Twist Property in KSS Curves of Embedding Degree 16 and 18 from the Implementation Perspective

Khandaker, Md. Al-Amin,Park, Taehwan,Nogami, Yasuyuki,Kim, Howon The Korea Institute of Information and Commucation 2017 Journal of information and communication convergen Vol.15 No.2

Implementation of faster pairing calculation is the basis of efficient pairing-based cryptographic protocol implementation. Generally, pairing is a costly operation carried out over the extension field of degree $k{\geq}12$. But the twist property of the pairing friendly curve allows us to calculate pairing over the sub-field twisted curve, where the extension degree becomes k/d and twist degree d = 2, 3, 4, 6. The calculation cost is reduced substantially by twisting but it makes the discrete logarithm problem easier if the curve parameters are not carefully chosen. Therefore, this paper considers the most recent parameters setting presented by Barbulescu and Duquesne [1] for pairing-based cryptography; that are secure enough for 128-bit security level; to explicitly show the quartic twist (d = 4) and sextic twist (d = 6) mapping between the isomorphic rational point groups for KSS (Kachisa-Schaefer-Scott) curve of embedding degree k = 16 and k = 18, receptively. This paper also evaluates the performance enhancement of the obtained twisted mapping by comparing the elliptic curve scalar multiplications.

Analysis of Shielded Twisted Pair Cable to External Field Coupling by Expanded Chain Matrix Modeling

Cho, Yong-Sun,Jung, Hyun-Kyo,Cheon, Changyul,Chung, Young-Seek The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.6

In this paper, a numerical method for analyzing coupling between high-altitude electromagnetic pulse (HEMP) as external field and a shielded twisted pair (STP) cable is proposed, which is based on an expanded chain matrix. Load responses of electromagnetic (EM) field excitation in uniform transmission line (TL) are solved by Baum-Liu-Tesche (BLT) equations in frequency domain, however, it is difficult to apply BLT equations to solve load responses of STP cable because the iteratively changing configuration of each twisted pairs are involved in cable. To avoid this problem and decrease memory and CPU time, we proposed the expanded chain matrix modeling method that is calculated using ABCD parameters, and applied multi-conductor transmission line (MTL) theory to consider the EMP coupling effectiveness of each twisted pairs. The results implemented by the proposed method are presented and compared with those obtained by the finite-difference time domain (FDTD) method as a kind of 3D full wave analysis.

Analysis of Shielded Twisted Pair Cable to External Field Coupling by Expanded Chain Matrix Modeling

Yong-Sun Cho,Hyun-Kyo Jung,Changyul Cheon,Young-Seek Chung 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.6

In this paper, a numerical method for analyzing coupling between high-altitude electromagnetic pulse (HEMP) as external field and a shielded twisted pair (STP) cable is proposed, which is based on an expanded chain matrix. Load responses of electromagnetic (EM) field excitation in uniform transmission line (TL) are solved by Baum-Liu-Tesche (BLT) equations in frequency domain, however, it is difficult to apply BLT equations to solve load responses of STP cable because the iteratively changing configuration of each twisted pairs are involved in cable. To avoid this problem and decrease memory and CPU time, we proposed the expanded chain matrix modeling method that is calculated using ABCD parameters, and applied multi-conductor transmission line (MTL) theory to consider the EMP coupling effectiveness of each twisted pairs. The results implemented by the proposed method are presented and compared with those obtained by the finitedifference time domain (FDTD) method as a kind of 3D full wave analysis.

Wear-Induced Attenuation on Transmission Lines and Their Causes

Philipp Lenz,Philipp Baron,Armin Wittmann,Georg Fischer 한국전기전자재료학회 2023 Transactions on Electrical and Electronic Material Vol.24 No.1

In this paper, the radio frequency (RF) behavior of mechanically stressed coaxial and for the first time also twisted-pair transmission lines is investigated over their service life. The main goal is to enable predictive maintenance for cables in moving applications and avoid preventive replacement. This also reduces the use of high-cost resources. For this purpose, stranded and solid-core variants of coaxial and twisted-pair type cables are mechanically loaded on the two-pulley apparatus according to EN 50396. Their RF transmission (S21) behavior is measured using a vector network analyzer and presented over bending cycles. For the first time, the phase response of mechanically loaded transmission lines is evaluated with respect to their service life. Two significant causes for the increasing attenuation and altered phase response are identified: breakage in foil screen and increasing surface roughness on the copper conductors. The identified causes are supported with literature evidence. Through measurements and theoretical calculations, it is proven that the phase is much more suitable for an assessment of the remaining service life than the amplitude. The findings can be used to implement a cable monitoring system in industrial environments which monitors the lines in-situ and reminds the user to replace them, whenever a certain wear-level is reached.

케이블 공진을 이용한 600V 제어/계측용 꼬임쌍선 차폐 케이블의 열화상태 진단에 대한 연구

신재영(JaeYoung Shin),김광호(KwangHo Kim),나완수(WanSoo Nah) 대한전기학회 2015 전기학회논문지 Vol.64 No.12

Recent major domestic facilities, such as nuclear power plants, many control cables are installed and are degraded by long-term use, but research on deterioration diagnosis is lacking. In the event of a fault in the cable due to deterioration can be developed into a major accident such as the main plant is stopped, so the deterioration diagnostic techniques of high reliability for the cable is required. In this paper, proposes a methodology using a cable resonance that can effectively diagnose the deterioration of the cable. Prior to the test, we developed a setup for stable measuring the characteristics of the cable and it verified the suitable of the measurement set-up in terms of interactivity and reliability, also measured S-parameters applying verified measurement set-up to the cables that deterioration degree is different. Then, we had amplified the difference in resonance frequency between the healthy state and the deteriorated state using connection in a series of measured S-parameters. In a result from the method, we have verified that the more deteriorate the cables is, the more decrease the resonance frequency is. Measured results are justified by inducing the resonance frequency calculation of the cable from the S- parameters represented by the hyperbolic function formula. VNA(Vector Network Analyzer) for S-parameter measurements used in this study is Agilent E5061B and shielded twisted-pair cables was used for deterioration diagnostic test.

Experimental Study and Fine-Tuned Simulation of Cable-Joint Pair Slipping in the Cable-Supported Structure

Renzhang Yan,Chunling Yan,Shuai Wang,Chongsheng Cheng,Ting Liu,Hongbo Liu 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.1

During the tensioning process of the cable-supported structure, the sliding friction between cable wires and joint will have a great influence on the mechanical properties of the structure. However, due to the complex structure of the cable and the combined action of bending deformation and large pre-tension at the cable-strut joint, it is difficult to accurately determine the coefficient of sliding friction (CSF) between cable wires and joint, and thus the overall mechanical properties of the structure cannot be accurately evaluated. Based on the twisting characteristics of the cable, this paper establishes a friction-slip test model and a refined numerical model to carry out detailed study of the mechanical behavior of contact between cable wires and joint during the tensioning process. Firstly, combined with the calculation results of contact mechanics, it is finds that the stress distribution at straight and curved sections of the cable are non-uniform along its axis and each cross section, and the non-uniformity coefficient of the internal force distribution of the cable is further quantified. At the same time, the local bending of the cable will intensify the uneven stress distribution in the circumferential direction of the cable. The non-uniformity of stress reveals the contact working mechanism of the cable-joint pair. Then, the change of the prestress loss between cable wires and joint with the tensioning process is analyzed, and the parametric analysis is conducted to reveal the effect of the cable included angle, tensile force, and lay length on the CSF. The results find that the prestress loss increases approximately linearly with the increase of tension force and decreases with the increase of the cable included angle, but the CSF is less affected by the lay length during the tensioning process. Finally, a method for valuing the CSF of the cable-supported structure is developed.

TWISTED FACE-PAIRING 3-MANIFOLDS WHICH ARE HYPERBOLIC

Hong, Sung-Bok,Lee, Kyung-Hwa Korean Mathematical Society 2010 대한수학회보 Vol.47 No.6

We construct a family of 3-balls using cones which represent closed orientable 3-manifolds and study twisted face-pairing construction due to Cannon, Floyd and Parry to understand the structure of such manifolds. Moreover, we prove that those manifolds are hyperbolic.

TWISTED FACE-PAIRING 3-MANIFOLDS WHICH ARE HYPERBOLIC

홍성복,이경화 대한수학회 2010 대한수학회보 Vol.47 No.6

We construct a family of 3-balls using cones which represent closed orientable 3-manifolds and study twisted face-pairing construction due to Cannon, Floyd and Parry to understand the structure of such manifolds. Moreover, we prove that those manifolds are hyperbolic.

차량환경에서의 와이어 종류에 따른 커플링 노이즈 계산과 저감 방안에 대한 연구

송승우(Seungwoo Song),김일구(Ealgoo Kim),Trinh Qui Ngoc,이태연(Taeyoen Lee),박재홍(Jaehong Park) 한국자동차공학회 2006 한국자동차공학회 Symposium Vol.- No.-

In this paper, noise between each type of wires in automotive is considered. Characteristic of coupling noise for each wire types is different. For different wire types like normal wire, twisted pair and shielded wire, the noise coupling varies. The noise for each wire type is calculated using models for near end and far end cases. The magnitude of coupling noise form noise source to each wire as noise receptor can be calculated with overlapped length and distance between source and receptor wires. This paper treats modeling of coupling between two wires and calculation of coupling noise. Result of this paper can be used as methods of wiring design to avoid noise problem.

자동차 이더넷 전선의 설계 인자 영향도 분석을 통한 통신 성능에 관한 연구

이성하(Seongha Lee),김병우(Byungwoo Kim) 한국자동차공학회 2018 한국자동차공학회 부문종합 학술대회 Vol.2018 No.6

Implementation of automotive Ethernet network, which can meet high speed communication and large capacity data demands, requires UTP design and Connector design so that the communication performance could be maintained even under automotive environment. In this paper, the design of communication technologies such as Automotive-Ethernet, focusing on characteristic impedance and electromagnetic compatibility.