Agonistic behavior of captive saltwater crocodile, crocodylus porosus in Kota Tinggi, Johor

Agonistic behavior in Crocodylus porosus is well known in the wild, but the available data regarding this behavior among the captive individuals especially in a farm setting is rather limited. Studying the aggressive behavior of C. porosus in captivity is important because the data obtained may contribute for conservation and the safety for handlers and visitors. Thus, this study focuses on C. porosus in captivity to describe systematically the agonistic behaviour of C. porosus in relation to feeding time, daytime or night and density per pool. This study was carried out for 35 days in two different ponds. The data was analysed using Pearson’s chi-square analysis to see the relationship between categorical factors. The study shows that C. porosus was more aggressive during daylight, feeding time and non-feeding time in breeding enclosure (Pond C, stock density =0.0369 crocodiles/m2) as compared to non-breeding pond (Pond B, stock density =0.3317 crocodiles/m2) where it is only aggressive during the nighttime. Pond C shows the higher domination in the value of aggression in feeding and non-feeding time where it is related to its function as breeding ground. Chi-square analysis shows that there is no significant difference between ponds (p=0.47, χ2= 2.541, df= 3), thus, there is no relationship between categorical factors. The aggressive behaviour of C. porosus is important for the farm management to evaluate the risk in future for the translocation process and conservation of C. porosus generally

Survey and Benchmark of Block Ciphers for Wireless Sensor Networks

Cryptographic algorithms play an important role in the security architecture of wireless sensor networks (WSNs). Choosing the most storage- and energy-efficient block cipher is essential, due to the facts that these networks are meant to operate without human intervention for a long period of time with little energy supply, and that available storage is scarce on these sensor nodes. However, to our knowledge, no systematic work has been done in this area so far.We construct an evaluation framework in which we first identify the candidates of block ciphers suitable for WSNs, based on existing literature and authoritative recommendations. For evaluating and assessing these candidates, we not only consider the security properties but also the storage- and energy-efficiency of the candidates. Finally, based on the evaluation results, we select the most suitable ciphers for WSNs, namely Skipjack, MISTY1, and Rijndael, depending on the combination of available memory and required security (energy efficiency being implicit). In terms of operation mode, we recommend Output Feedback Mode for pairwise links but Cipher Block Chaining for group communications

Self-Partial and Dynamic Reconfiguration Implementation for AES using FPGA

This paper addresses efficient hardware/software implementation approaches for the AES (Advanced Encryption Standard) algorithm and describes the design and performance testing algorithm for embedded system. Also, with the spread of reconfigurable hardware such as FPGAs (Field Programmable Gate Array) embedded cryptographic hardware became cost-effective. Nevertheless, it is worthy to note that nowadays, even hardwired cryptographic algorithms are not so safe. From another side, the self-reconfiguring platform is reported that enables an FPGA to dynamically reconfigure itself under the control of an embedded microprocessor. Hardware acceleration significantly increases the performance of embedded systems built on programmable logic. Allowing a FPGA-based MicroBlaze processor to self-select the coprocessors uses can help reduce area requirements and increase a system's versatility. The architecture proposed in this paper is an optimal hardware implementation algorithm and takes dynamic partially reconfigurable of FPGA. This implementation is good solution to preserve confidentiality and accessibility to the information in the numeric communication

Algebraic properties of generalized Rijndael-like ciphers

We provide conditions under which the set of Rijndael functions considered as permutations of the state space and based on operations of the finite field \GF (p^k) ($p\geq 2$ a prime number) is not closed under functional composition. These conditions justify using a sequential multiple encryption to strengthen the AES (Rijndael block cipher with specific block sizes) in case AES became practically insecure. In Sparr and Wernsdorf (2008), R. Sparr and R. Wernsdorf provided conditions under which the group generated by the Rijndael-like round functions based on operations of the finite field \GF (2^k) is equal to the alternating group on the state space. In this paper we provide conditions under which the group generated by the Rijndael-like round functions based on operations of the finite field \GF (p^k) ($p\geq 2$) is equal to the symmetric group or the alternating group on the state space.Comment: 22 pages; Prelim0

Power analysis on smartcard algorithms using simulation

This paper presents the results from a power analysis of the AES and RSA algorithms by\ud simulation using the PINPAS tool. The PINPAS tool is capable of simulating the power\ud consumption of assembler programs implemented in, amongst others, Hitachi H8/300\ud assembler. The Hitachi H8/300 is a popular CPU for smartcards. Using the PINPAS tool, the\ud vulnerability for power analysis attacks of straightforward AES and RSA implementations is\ud examined. In case a vulnerability is found countermeasures are added to the implementation\ud that attempt to counter power analysis attacks. After these modifications the analysis is\ud performed again and the new results are compared to the original results

Supervisory control for conventional unitary air conditioning system

The Supervisory control for conventional unitary air conditioning system is conceptually designed based on Programmable Logic Control (PLC) system. The advantage of PLC system is that it allows online monitoring continually and updates or modification can be performed interactively. This supervisory mode is applied to the conventional unitary air conditioner to avoid the frequent interruption or adjustment of the fan speed or temperature set point by users normal practice which has contributed to the surge of energy consumption due to the frequent on/off of the compressor. Three experiments have been performed at different control methods to simulate user’s daily practice. The first control method is the Variable Set point with high speed fan, the second control method is the Fixed Set point with high speed fan and the third control method is a Supervisory Control; a fixed set point with variable fan speed. The experiments have been conducted for eight (8) hours and the statistic data of accumulated energy consumption based on one unitary air conditioner with capacity of 1 Horse Power are acquired and sampled at the time interval of 30 minutes for the analysis. From these experiments, the supervisory control has consumed 4.2 kWh per day which is 82.35% compared to normal consumption of 5.1 kWh. This result translated into 0.9 kWh or 17.65% of total energy saving per day. The consistency of the air compressor operation in this control method has become a major factor in achieving indoor temperature steadiness whilst improving the energy savings

Study mass transfer of Cd, Hg, As, DDT and chlordane through adsorption onto granular activated carbon

The kinetic theory of liquid indicates that diffusion coefficient for the dilute liquid at ordinary pressure is essentially independent of mixture composition. Mass transfer is important in separation and adsorption process. However, diffusion may also be caused by other features. Because of the complex nature of mass diffusion, the diffusion coefficients are usually determined experimentally. The mass transfer resistance controls the kinetic adsorption rate, but there is only limited understanding of the adsorption of a solute onto porous material from surface water. Thus, this study was conducted to further enhance the understanding of the mass transfer and adsorption processes of micropollutants. The objectives of this study are to analyze the difference, examine the adsoprtion diffusion of mass transfer and evaluate the variation of total, internal and external mass transfer. This study also used the transformed equation to analyze the rate of adsorption during adsorption process onto different GACs. Five (5) micropollutants namely Hg, Cd, As, DDT and chlordane have been chosen to be adsorbed onto three (3) granular activated carbon which are SIG (shell industrial grade), SAG (shell analytical grade) and BAG (bitumen analytical grade). The micropollutants (Hg, Cd, As, DDT and chlordane) were prepared using standard stock solution in deionized water. Adsorption of pollutants onto SIG, SAG, and BAG were started at different percentages of outflow. Although the samples were taken at the same time, the outcome showed that a significant competition between adsorbates and adsorbents. From the analysis, SIG and SAG displayed excellent performance in adsorbing inorganic micropollutants while BAG for organic micropollutants. Before adsorption takes place, the morphology of the SAG indicated pore abundance compared to SIG and BAG. BAG pores are more structured than SIG and SAG. After adsorption occurs, more of the organic micropollutants are being adsorbed onto BAG and SAG. Meanwhile, SIG proved to be the best adsorbent for inorganic micropollutants. It takes 72 hours for Hg vi and As to saturate SIG whilst Cd take a longer time of 80 hours. SAG was also a good adsorbent for organic elements, with DDT taking 52 hours and chlordane taking 48 hours to be adsorbed. The [KLa]f value for the adsorption of Hg onto SIG was significant and the [KLa]d value for the adsorption of Hg onto SIG was higher onto SAG and BAG. The value of [KLa]f for SIG at 6% outflow was 0.6862 h-1, with values of [KLa]d at -0.4142 h-1 and [KLa]g at 0.2721 h-1, while for the adsorption of Cd it was shown that the [KLa]f values for the adsorption of Cd onto BAG was the most significant and the [KLa]d values for the adsorption of Cd onto SIG was higher than SAG and BAG at 2% outflow, with values of 0.7044 h-1, [KLa]d at -0.3687 h-1, and [KLa]g at 0.3356 h-1. In contrast, for As the [KLa]f for the adsorption of As onto BAG at 4% outflow was 0.6722 h-1 and [KLa]g was 0.3103 h-1. For DDT, the [KLa]f value of DDT for BAG at 0.5% outflow was 1.6662 h-1, [KLa]d was -1.2702 h-1 and [KLa]g was 0.3959 h-1. In the case of DDT, the value of [KLa]f for the adsorption of chlordane onto BAG at 2% outflow was 0.7330 h-1 and [KLa]d was started to activate the adsorption -0.5567 h-1. [KLa]g at 2% outflow was 0.1763 h-1. From these values we can conclude that for the adsorption of inorganic substances, SIG proved to be the best, while for organic substances BAG is the best adsorbent

Efficient software implementation of AES on 32-bit platforms

Rijndael is the winner algorithm of the AES contest; therefore it should become the most used symmetric-key cryptographic algorithm. One important application of this new standard is cryptography on smart cards. In this paper we present an optimisation of the Rijndael algorithm to speed up execution on 32-bits processors with memory constraints, such as those used in smart cards. First a theoretical analysis of the Rijndael algorithm and of the proposed optimisation is discussed, and then simulation results of the optimised algorithm on different processors are presented and compared with other reference implementations, as known from the technical literature