H-ORAM: A Cacheable ORAM Interface for Efficient I/O Accesses

Oblivious RAM (ORAM) is an effective security primitive to prevent access pattern leakage. By adding redundant memory accesses, ORAM prevents attackers from revealing the patterns in the access sequences. However, ORAM tends to introduce a huge degradation on the performance. With growing address space to be protected, ORAM has to store the majority of data in the lower level storage, which further degrades the system performance. In this paper, we propose Hybrid ORAM (H-ORAM), a novel ORAM primitive to address large performance degradation when overflowing the user data to storage. H-ORAM consists of a batch scheduling scheme for enhancing the memory bandwidth usage, and a novel ORAM interface that returns data without waiting for the I/O access each time. We evaluate H-ORAM on a real machine implementation. The experimental results show that that H-ORAM outperforms the state-of-the-art Path ORAM by 19.8x for a small data set and 22.9x for a large data set

Current Advances in the Biosynthesis, Metabolism, and Transcriptional Regulation of α-Tomatine in Tomato

Steroid glycoalkaloids (SGAs) are a class of cholesterol-derived metabolites commonly found in the Solanaceae plants. α-Tomatine, a well-known bitter-tasting compound, is the major SGA in tomato, accumulating extensively in all plant tissues, particularly in the leaves and immature green fruits. α-Tomatine exhibits diverse biological activities that contribute to plant defense against pathogens and herbivores, as well as conferring certain medicinal benefits for human health. This review summarizes the current knowledge on α-tomatine, including its molecular chemical structure, physical and chemical properties, biosynthetic and metabolic pathways, and transcriptional regulatory mechanisms. Moreover, potential future research directions and applications of α-tomatine are also discussed

A novel spaceborne photon-counting laser altimeter denoising method based on parameter-adaptive density clustering

ABSTRACTTo tackle the challenge of denoising spaceborne photon-counting laser altimeter point clouds with uneven noise density, this study proposes a denoising method based on adaptive parameter density clustering, which utilizes numerical simulations to achieve self-adaptation of key parameters (neighborhood radius [Formula: see text] and minimum number of points [Formula: see text]). First, taking the directional adaptive ellipse DBSCAN (DAE-DBSCAN) as an example, photons with different background photon count rates ([Formula: see text]) are used to traverse [Formula: see text] and [Formula: see text] to calculate their optimal values ([Formula: see text] and [Formula: see text] with the highest denoising accuracy). Then, a mathematical prediction model of [Formula: see text], [Formula: see text] and [Formula: see text] was established. The actual background photon count rates were introduced into the key parameter prediction model to obtain the optimal [Formula: see text] and [Formula: see text]. Finally, a denoising experiment was conducted using the simulated photons and the ATLAS data. The results show that the proposed method had higher accuracy than the constant parameter denoising method, with an [Formula: see text] >0.95. Even for photons of complex mountainous terrain with a high background photon count rate, the denoising accuracy was still higher than 0.9. The proposed method improves the denoising accuracy of photons with different noise densities by adapting density clustering parameters

Comprehensive Chemical Dust Suppressant Performance Evaluation and Optimization Method

Chemical dust suppression is an effective dust control technology. A dust suppressant component evaluation method that facilitates a complete selection of safe, efficient, and economical chemical materials has not been explored. Considering dust suppression performance, environmental safety, and cost-effectiveness of chemical dust suppressant technology, this study constructs a comprehensive evaluation index system of chemical dust suppressant performance, including the wetting performance, hygroscopic performance, bonding performance, annual cost per unit area, pH value of dust suppression solution, chemical toxicity, and chemical corrosion. Among them, the index characterizing the wetting performance of the solution is the sedimentation wetting time, which is determined by the dust sedimentation experiment; the index characterizing the hygroscopic performance of the solution is the evaporation stability time, which is determined by the evaporation experiment of the solution on the dust surface; the index to characterize the bonding performance of the solution is the surface wind erosion rate, which is determined by the wind erosion experiment of the solution on the dust surface; the toxicity of the solution is evaluated by the LD50 of the solution; the index to characterize the corrosion performance of the solution is the Q235 monthly steel corrosion rate, which is determined by the Q235 steel corrosion test. Corresponding evaluation parameters are determined including sedimentation wetting time, evaporation stabilization time, surface wind erosion rate; annual average use cost per unit area; solution pH value, chemical acute toxicity classification, monthly corrosion rate of Q235 steel, and corresponding standard test methods are also provided. In order to evaluate the comparability of the results, according to the specific requirements of the evaluation index system and the distribution characteristics of the measurement data, the data of each evaluation and detection index are standardized by linear transformation, range transformation and other methods, so that the obtained results are comparable. Considering the differences in the actual performance requirements of dust suppressants in different usage scenarios, the weights of evaluation indicators at all levels can be set independently and flexible. The experimental test data obtained through the example shows that: among the four chemicals selected to participate in the experiment, the comprehensive dust suppression performance score of Triton X-100 solution is in the poor-grade category. The comprehensive dust suppression performances of calcium chloride solution, water, and polyacrylamide solution scored high in the average-grade category. The comprehensive evaluation process is logically correct, and the results are consistent with the phenomena observed in the experiment, consistent with conventional understanding, and have strong credibility. This method can provide a standardized evaluation technique and test process for the comprehensive performance evaluation and comparison of chemical materials and dust suppressants

An offline delegatable cryptocurrency system

Blockchain-based cryptocurrencies, facilitating the convenience of payment by providing a decentralized online solution, have not been widely adopted so far due to slow confirmation of transactions. Offline delegation offers an efficient way to exchange coins. However, in such an approach, the coins that have been delegated confront the risk of being spent twice since the delegator's behaviour cannot be restricted easily on account of the absence of effective supervision. Even if a third party can be regarded as a judge between the delegator and delegatee to secure transactions, she still faces the threat of being compromised or providing misleading assure. Moreover, the approach equipped with a third party contradicts the real intention of decentralized cryptocurrency systems. In this paper, we propose \textit{DelegaCoin}, an offline delegatable cryptocurrency system to mitigate such an issue. We exploit trusted execution environments (TEEs) as decentralized "virtual agents" to prevent malicious delegation. In DelegaCoin, an owner can delegate his coins through offline-transactions without interacting with the blockchain network. A formal model and analysis, prototype implementation, and further evaluation demonstrate that our scheme is provably secure and practically feasible.Comment: ICBC2

Study on evaluation method of insulation performance of mine cable based on dielectric response method

The high voltage cable used in mine is affected by many factors, such as electricity, heat and machinery stress. These factors accelerate insulation aging and easily lead to cable leakage, short circuit or discharge. At present, the dielectric response method is introduced into analysis, evaluation and diagnosis of insulation performance and aging state of mine cables. In view of problems of insulation performance and aging state evaluation of mine cables, the commonly used ethylene propylene diene monomer (EPDM) insulated mobile flexible cable for mining is taken as the research object. The basic principles and typical characteristics of recovery voltage method, polarization/depolarization current method and frequency-domain dielectric spectroscopy method in dielectric response method are summarized. The advantages and disadvantages of the three methods are compared. The characteristics of cable insulation performance evaluation based on the dielectric response model are introduced. The characteristics include the aging factor extracted by the extended Debye model, relaxation characteristics extracted by the modified dielectric relaxation model and dielectric loss integral spectrum. The application of the dielectric response method in the evaluation of the insulation performance of mine cables is summarized from the following aspects. The aspects include the identification of trace corrosion degree of mine cables based on recovery voltage method and polarization/depolarization current method. The aspects include the evaluation of EPDM insulation multi-stress aging state based on polarization/depolarization current method and isothermal relaxation current, based on dielectric relaxation model and based on dielectric loss integral value. The existing online monitoring technology for the evaluation of the insulation performance of mine cables based on the dielectric response method cannot adapt to the working conditions of coal mines. The evaluation data is insufficient, and the relationship between the insulation deterioration degree and the characteristic quantity is unknown. In order to solve the above problems, this paper puts forward that the research should focus on two key technologies, namely, cable insulation state perception and the relationship between insulation degradation degree and characteristic quantity construction