Linearization Study of a Highly Efficient CMOS-GaN RF Pulse Width Modulation Based Transmitter

This paper studies linearity of a 2 GHz, 10 Watt peak output power RF pulse width modulation (RF-PWM) based transmitter. The transmitter incorporates a tunable load network class-E PA as the final output stage. The tunable load network enables dynamic optimization of the class-E along with the duty cycle resulting in high efficiency over a wide range of output power levels. A digital predistiortion based linearization scheme is proposed to enhance the linearity of the transmitter. After linearization, the transmitter exhibits an adjacent channel power ratio (ACPR) of -45 dBc with a 3.84 MHz, 6.7 dB peak-to-average power ratio (PAPR) W-CDMA signal. The average drain efficiency of the GaN HEMT output stage is 67% and the total transmitter efficiency is 54%

Pediyatrik yaş grubunda trafik kazası sonucu oluşan yaralanmalar ve özellikleri

BACKGROUND In this study, the pediatric age group exposed to road traffic accidents was investigated, and patients with risk factors were studied to obtain relevant data. METHODS Trauma patients under the age of 15 who were admitted to the emergency department of this university over five years were analyzed retrospectively. Age, gender, accident time and type, personal injury area, type of injury, and clinical outcome were examined. RESULTS When the cases were analyzed with respect to the causes that led to the accidents, in-vehicle accidents formed the largest group (n=479, 59%). More than a quarter of all applications (34%) took place in summer months. Most of the applications were between 17:00 and 17:59 (n=94, 11.6%), followed by between 18:00 and 18:59 (n=88, 10.8%). The most commonly affected body parts were the head and neck region (n=226, 27.8%) and extremities (lower extremity: n=144, 17.7%; upper extremity: n=99, 12.2%). The most frequently seen injuries were contusions, abrasions, hematomas, and crush (n=443, 54.6%). The majority of patients who died were pedestrians who were hit by a motor vehicle (n=19, 59.4%). CONCLUSION In this study, it was observed that in the pediatric age group, traffic accidents involving a pedestrian and vehicle collision have greater fatality

A Guess-and-Determine Attack on Reduced-Round Khudra and Weak Keys of Full Cipher

Khudra is a lightweight block cipher designed for Field Programmable Gate Array (FPGA) based platforms. The cipher has an 18-round generalized type-2 Feistel structure with 64-bit block size. The key schedule takes 80-bit master key and produces 32-bit round keys performing very simple operations. In this work, we analyze the security of Khudra. We first show that the effective round key length is 16-bit. By the help of this observation, we improve the 14-round MITM attack proposed by Youssef et al. by reducing the memory complexity from $2^{64.8}$ to $2^{32.8}$. Also, we propose a new guess-and-determine type attack on 14 rounds where only 2 known plaintext-ciphertext pairs are required to mount the attack in a time complexity of $2^{64}$ encryption operations. To the best of our knowledge, this is the best attack in the single key model in terms of time, memory and data complexities where the data complexity is equal to the minimum theoretical data requirement. Moreover, we present two observations on differential probabilities of the round function and the symmetric structure of the cipher. We introduce $2^{40}$ weak keys for the full cipher by exploiting the symmetric structure of the cipher

Feistel Like Construction of Involutory Binary Matrices With High Branch Number

In this paper, we propose a generic method to construct involutory binary matrices from a three round Feistel scheme with a linear round function. We prove bounds on the maximum achievable branch number (BN) and the number of fixed points of our construction. We also define two families of efficiently implementable round functions to be used in our method. The usage of these families in the proposed method produces matrices achieving the proven bounds on branch numbers and fixed points. Moreover, we show that BN of the transpose matrix is the same with the original matrix for the function families we defined. Some of the generated matrices are \emph{Maximum Distance Binary Linear} (MDBL), i.e. matrices with the highest achievable BN. The number of fixed points of the generated matrices are close to the expected value for a random involution. Generated matrices are especially suitable for utilising in bitslice block ciphers and hash functions. They can be implemented efficiently in many platforms, from low cost CPUs to dedicated hardware

A non-linear elastic-plastic stress analysis in a ductile double-lap joint

In this study, an elastic-plastic stress analysis was proposed in order to obtain shear stress distribution in a double-lap joint, analytically. The solution was carried out using incremental theory. The obtained shear stress was then used for determining the peel stress in the adhesive. The elastic peel stress distribution in the adhesive was determined using Newton-Raphson method. In this study, FM73 (Cytec Industries Inc., New Jersey, USA) ductile adhesive was selected as it represents plastic hardening. The analytical results were compared with the finite element solution. For that, ANSYS 10 Software (Figes Engineering A.S., Turkey) was used so as to compare with the analytical results. A good agreement was obtained between the two methods

Synthesis, characterization, and biological evaluation of new oxime-phosphazenes

Hexachlorocylotriphosphazene (1) was reacted with 4-hydroxy-3-methoxybenzaldehyde to give hexakis[(4-formyl-2-methoxy)phenoxy]cyclotriphosphazene (2). Hexakis[(4-(hydroxyimino)2-methoxy)phenoxy]cyclotriphosphazene (3) was synthesized by reaction of 2 with hydroxlamine hydrochloride in pyridine. Compound 3 was reacted with benzyl chloride, acetyl chloride, allyl bromide, benzoyl chloride, propanoyl chloride, 4-methoxybenzoyl chloride, 2-chlorobenzoyl chloride, chloroacetyl chloride, methyl iodide, and thiophene-2-carbonyl chloride. From these reactions, full or partially substituted compounds were obtained, usually in high yields. Pure or defined products could not be obtained from reaction of 3 with methacryloyl chloride and O-acetylsalicyloyl chloride. The structures of the compounds were determined by elemental analysis, and IR, 1H, 13C, and 31P NMR spectroscopy. The synthesized compounds were screened for in-vitro antimicrobial activity against two Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis), two gram-negative bacteria (Escherichia coli and Klebsiella pneumonia), and fungal strains (Aspergillus niger, and Candida albicans) by the agar well diffusion method. Few compounds had significant activity against both Gram-positive and Gram-negative bacteria. None of the compounds had antifungal activity except compounds 7 and 9, which had moderate activity.Sponsor Kurum Adı: Fırat Üniversitesi Finansman Kodu: FF.11.0

A New Approach to the Determination of Warp-Weft Densities in Textile Fabrics by Using an Image Processing Technique

ABSTRACT This paper presents a new approach for processing images of woven fabrics to determine the warp-weft densities. This approach includes three main steps, namely; image transformation, image enhancement, and analyzing signals of the image. In the experimental process, 19 different woven fabric images were scanned at a high resolution (2400 dpi); then these images were transferred to the MATLAB program. By using the vertical and horizontal frequencies of the textile image, the FFT analyses were carried out. Consequently with 97 % accuracy, the densities were predicted only by using the images instead of counting them by hand