just a couple of years, suggesting a bright future for PV application. [15][16][17] To date, a number of processing technologies have been developed to fabricate perovskites, such as solution process, [2,3,[18][19][20][21] thermal evaporation, [22,23] flash evaporation, [24] atomic layer deposition (ALD), [25] doctor-blade coating, [26] slot-die coating, [27] spray deposition, [28] and ink-jet printing, [29] etc. Among various approaches, the most studied solution method not only achieves highly efficient PSCs but also owns cost advantage. However, the uncontrolled over-rapid liquid reaction often generates rough and porous films with incomplete conversions, resulting in large variations on film morphology and PV response. [18][19][20][21] Inversely, thermal evaporation can generate high-quality films with smooth and pinhole-free morphologies, in which the moderate gas-phase reaction characteristic effectively relieves the reaction rate. Nevertheless, there are a few of disadvantages in vacuum process, for instance, low material utilization, high equipment investment and energy consumption, hampering its further application. [22][23][24][25] The rest technologies often produce poor film quality, and are also difficult to scale up. [26][27][28][29] Therefore, development of a new class of advanced fabrication technology shall be critical for the future commercialization of PSCs.In 2013, a radically different technology, that is, vapor-assisted solution process (VASP), is invented by Yang and coworkers. [30] This method combines the advantages of gas-phase deposition and solution process. Concretely speaking, PbI 2 films are first spin-coated as the precursors, and then reacted with MAI vapor in a closed room. The attraction of this work is that film growth via in situ gas-solid (G-S) reaction, which is considered as a fruitful way for preparing perovskites. Subsequently, similar G-S crystallization and other modified VASP approaches are reported. [31][32][33] However, VASP methods require manipulations in glove box or protecting atmosphere, and show poor controllability and versatility, unsuitable for their mass production. Soon after, as an evolution of VASP, more convenient tubular CVD technology is successively developed by independent groups. [34][35][36] This simple and low-cost film growth method provides excellent controllability and repeatability for batch processing, which has been regarded as a cost-effective road for fabricating high-quality perovskites. Subsequently, an array of CVD techniques, such as in situ tubular CVD (ITCVD), [37] one-step tubular CVD, [38] aerosol-assisted CVD (AACVD), [39][40][41][42] hybrid physical-chemical vapor deposition (HPCVD), [43] modified chemical vapor transport (mCVT), [44] and so on, are consecutively invented, and remarkable achievements of PSCs by In recent years, high-efficient and low-cost perovskite solar cells (PSCs) have triggered a strong interest in the photovoltaic (PV) field. However, it is still challenging to develop cost-effective perovskite fabricatio...

No abstract

Due to the increasing number of network security vulnerabilities, vulnerability risk assessment must be performed to prioritize the repair of high-risk vulnerabilities. Traditional vulnerability risk assessment is based primarily on the Common Vulnerability Scoring Systems (CVSS) and attack graphs. Nevertheless, the CVSS metrics ignore the impact of the vulnerability on the specific network, which accounts that the identical vulnerability exists in different network environments is assigned repeated values. Additionally, the attack graphs still suffer from scalability and readability issues. To solve the above problems, a ranking method based on the heterogeneous information network is innovatively proposed to assess the vulnerability risk in a specific network. It considers the exploitability of a vulnerability, the impact of a vulnerability on the network components, and the importance of the vulnerable components. First, a heterogeneous information network containing vulnerability and host and the relationships between host and host is constructed to compute the risk score for each vulnerability and implement the ranking process. Second, a model extension method is proposed to adapt to situations in which additional factors related to vulnerability risk assessment need to be considered. Finally, we explore two case studies to compare the proposed method with CVSS and attack graph-based methods. The simulation results show that the proposed method can accurately assess the risk of vulnerabilities in a specific network environment and that it has a lower computational complexity than other methods. INDEX TERMS Common vulnerability scoring systems (CVSS), vulnerability, risk assessment, information fusion, heterogeneous information network.

No abstract

No abstract