Modul Simulator Pembangkitan Sinyal Pseudo Random Generator pada Sistem Komunikasi Spread Spectrum Memanfaatkan Microcontroller

Sebuah modul simulator perangkat keras untuk sinyal pseudo random generator (PRG) telah dibuat dengan memanfaatkan microcontroller 8951. Dari data pengujian sistem pemancar dan bagian penerima telah menunjukkan bahwa simulator ini mampu menunjukkan 3 sifat dasar dari sebuah spreading dan despreading pada sistem direct sequence spread spectrum (DSSS), yaitu autokorelasi, balance property dan run property. Dengan input base band sebesar 4 kHz, sistem ini mampu memberikan coding gain sebesar 8, 2 dB.

Hamiltonian formulation and energy-based control for space tethered system deployment and retrieval

Usually, the dynamic equations of tethered systems are derived using Lagrangian formulation. However, Hamiltonian formulation is also widely used for mechanical systems because of its well-known symplectic structure property. In this paper, the dynamic equations of the tethered system are deduced using Hamiltonian formulation. The goodness of the Hamiltonian formulation is intuitive to reveal the energy balance property that corresponds to the passive property. Furthermore, the Hamiltonian function of the tethered system is employed to facilitate the design of the controller. The energy-based control is to achieve the tether deployment/retrieval with suppressing the tether liberation. Numerical simulations are used to demonstrate the effectiveness of the designed controller.

Backpressure propagation mode and balance property in a rectangular duct

The backpressure propagation mode accompanied by shock-train evolution is investigated numerically in a rectangular duct with an open space. On this basis, the balance mechanism and parametric effects of heat transfer and skin friction for backpressure propagation are revealed to understand the nature of force competition better. As a result, the backpressure propagation mode can be classified into two different flow processes with increased backpressure. In addition, balance property mechanism reveals that both the momentum inside the boundary layer and the shear force which transfers the momentum from the outer core flow to boundary layer are combined to resist the adverse pressure gradient. Further, parametric effect indicates that varying wall temperatures and roughness heights lead to different degrees of changes in balance property. According to quantitative results, both wall temperature and roughness height decrease the local boundary-layer momentum at the starting point of original pressure rise and thus the local adverse pressure gradient wins the force competition. In the subsequently continuous flow, the adverse pressure gradient continues to propagate upstream and then is retarded gradually by the boundary layer with a fuller velocity profile until a new force balance is generated.

Incomplete split-block designs constructed by affine α-resolvable designs

Summary We construct an incomplete split-block design (ISBD) by the semi- Kronecker product of two affine α-resolvable designs for row and column treatments. We characterize such ISBDs with respect to the general balance property and we give the stratum efficiency factors for the ISBDs.

Use of α-resolvable designs in the construction of two-factor experiments of split-plot type

We consider an incomplete split-plot design (ISPD) with two factors generated by the semi-Kronecker product of two α-resolvable designs. We use an α-resolvable design for the whole plot treatments and an affine α-resolvable design for the subplot treatments. We characterize the ISPDs with respect to the general balance property, and we give the stratum efficiency factors for the ISPDs.

Security Analysis of Cipher ICEBERG against Bit-pattern Based Integral Attack

Significant progress in the development of lightweight symmetric cryptographic primitives has been made in recent years. Security of ciphers against current cryptanalysis methods should be carefully evaluated. Integral attack is one of the most effective attacks against block ciphers. However, traditional integral attack based on byte or word is not available for a bit-oriented cipher. Bit-pattern based integral attack technique, introduced by Z'aba et al. addresses this issue to some extent. In this paper, bit-pattern based integral attack is applied to ICEBERG—a lightweight block cipher efficient in reconfigurable hard-ware. By tracing the propagation of the plaintext structure at bit-level, the balance property is obtained and then key guesses are verified. The result shows that 3, 4 and 5 rounds ICEBERG are not immune to this attack. All attacks presented in this paper manage to recover the full subkeys of the final round.