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Asanjarani, Azam.  2016.  QBD Modelling of a Finite State Controller for Queueing Systems with Unobservable Markovian Environments. Proceedings of the 11th International Conference on Queueing Theory and Network Applications. :20:1–20:4.

We address the problem of stabilizing control for complex queueing systems with known parameters but unobservable Markovian random environment. In such systems, the controller needs to assign servers to queues without having full information about the servers' states. A control challenge is to devise a policy that matches servers to queues in a way that takes state estimates into account. Maximally attainable stability regions are non-trivial. To handle these situations, we model the system under given decision rules. The model is using Quasi-Birth-and-Death (QBD) structure to find a matrix analytic expression for the stability bound. We use this formulation to illustrate how the stability region grows as the number of controller belief states increases.

Phan, Trung V., Islam, Syed Tasnimul, Nguyen, Tri Gia, Bauschert, Thomas.  2019.  Q-DATA: Enhanced Traffic Flow Monitoring in Software-Defined Networks applying Q-learning. 2019 15th International Conference on Network and Service Management (CNSM). :1–9.
Software-Defined Networking (SDN) introduces a centralized network control and management by separating the data plane from the control plane which facilitates traffic flow monitoring, security analysis and policy formulation. However, it is challenging to choose a proper degree of traffic flow handling granularity while proactively protecting forwarding devices from getting overloaded. In this paper, we propose a novel traffic flow matching control framework called Q-DATA that applies reinforcement learning in order to enhance the traffic flow monitoring performance in SDN based networks and prevent traffic forwarding performance degradation. We first describe and analyse an SDN-based traffic flow matching control system that applies a reinforcement learning approach based on Q-learning algorithm in order to maximize the traffic flow granularity. It also considers the forwarding performance status of the SDN switches derived from a Support Vector Machine based algorithm. Next, we outline the Q-DATA framework that incorporates the optimal traffic flow matching policy derived from the traffic flow matching control system to efficiently provide the most detailed traffic flow information that other mechanisms require. Our novel approach is realized as a REST SDN application and evaluated in an SDN environment. Through comprehensive experiments, the results show that-compared to the default behavior of common SDN controllers and to our previous DATA mechanism-the new Q-DATA framework yields a remarkable improvement in terms of traffic forwarding performance degradation protection of SDN switches while still providing the most detailed traffic flow information on demand.
Wang, Xiaolan, Meliou, Alexandra, Wu, Eugene.  2016.  QFix: Demonstrating Error Diagnosis in Query Histories. Proceedings of the 2016 International Conference on Management of Data. :2177–2180.

An increasing number of applications in all aspects of society rely on data. Despite the long line of research in data cleaning and repairs, data correctness has been an elusive goal. Errors in the data can be extremely disruptive, and are detrimental to the effectiveness and proper function of data-driven applications. Even when data is cleaned, new errors can be introduced by applications and users who interact with the data. Subsequent valid updates can obscure these errors and propagate them through the dataset causing more discrepancies. Any discovered errors tend to be corrected superficially, on a case-by-case basis, further obscuring the true underlying cause, and making detection of the remaining errors harder. In this demo proposal, we outline the design of QFix, a query-centric framework that derives explanations and repairs for discrepancies in relational data based on potential errors in the queries that operated on the data. This is a marked departure from traditional data-centric techniques that directly fix the data. We then describe how users will use QFix in a demonstration scenario. Participants will be able to select from a number of transactional benchmarks, introduce errors into the queries that are executed, and compare the fixes to the queries proposed by QFix as well as existing alternative algorithms such as decision trees.

Guo, Xiaolong, Dutta, Raj Gautam, He, Jiaji, Tehranipoor, Mark M., Jin, Yier.  2019.  QIF-Verilog: Quantitative Information-Flow based Hardware Description Languages for Pre-Silicon Security Assessment. 2019 IEEE International Symposium on Hardware Oriented Security and Trust (HOST). :91—100.
Hardware vulnerabilities are often due to design mistakes because the designer does not sufficiently consider potential security vulnerabilities at the design stage. As a result, various security solutions have been developed to protect ICs, among which the language-based hardware security verification serves as a promising solution. The verification process will be performed while compiling the HDL of the design. However, similar to other formal verification methods, the language-based approach also suffers from scalability issue. Furthermore, existing solutions either lead to hardware overhead or are not designed for vulnerable or malicious logic detection. To alleviate these challenges, we propose a new language based framework, QIF-Verilog, to evaluate the trustworthiness of a hardware system at register transfer level (RTL). This framework introduces a quantified information flow (QIF) model and extends Verilog type systems to provide more expressiveness in presenting security rules; QIF is capable of checking the security rules given by the hardware designer. Secrets are labeled by the new type and then parsed to data flow, to which a QIF model will be applied. To demonstrate our approach, we design a compiler for QIF-Verilog and perform vulnerability analysis on benchmarks from Trust-Hub and OpenCore. We show that Trojans or design faults that leak information from circuit outputs can be detected automatically, and that our method evaluates the security of the design correctly.
Alabadi, Montdher, Albayrak, Zafer.  2020.  Q-Learning for Securing Cyber-Physical Systems : A survey. 2020 International Congress on Human-Computer Interaction, Optimization and Robotic Applications (HORA). :1–13.
A cyber-physical system (CPS) is a term that implements mainly three parts, Physical elements, communication networks, and control systems. Currently, CPS includes the Internet of Things (IoT), Internet of Vehicles (IoV), and many other systems. These systems face many security challenges and different types of attacks, such as Jamming, DDoS.CPS attacks tend to be much smarter and more dynamic; thus, it needs defending strategies that can handle this level of intelligence and dynamicity. Last few years, many researchers use machine learning as a base solution to many CPS security issues. This paper provides a survey of the recent works that utilized the Q-Learning algorithm in terms of security enabling and privacy-preserving. Different adoption of Q-Learning for security and defending strategies are studied. The state-of-the-art of Q-learning and CPS systems are classified and analyzed according to their attacks, domain, supported techniques, and details of the Q-Learning algorithm. Finally, this work highlight The future research trends toward efficient utilization of Q-learning and deep Q-learning on CPS security.
Nikravesh, Ashkan, Hong, David Ke, Chen, Qi Alfred, Madhyastha, Harsha V., Mao, Z. Morley.  2016.  QoE Inference Without Application Control. Proceedings of the 2016 Workshop on QoE-based Analysis and Management of Data Communication Networks. :19–24.
Network quality-of-service (QoS) does not always directly translate to users' quality-of-experience (QoE), e.g., changes in a video streaming app's frame rate in reaction to changes in packet loss rate depend on various factors such as the adaptation strategy used by the app and the app's use of forward error correction (FEC) codes. Therefore, knowledge of user QoE is desirable in several scenarios that have traditionally operated on QoS information. Examples include traffic management by ISPs and resource allocation by the operating system (OS). However, today, entities such as ISPs and OSes that implement these optimizations typically do not have a convenient way of obtaining input from applications on user QoE. To address this problem, we propose offline generation of per-application models mapping application-independent QoS metrics to corresponding application-specific QoE metrics, thereby enabling entities (such as ISPs and OSes) that can observe a user's network traffic to infer the user's QoE, in the absence of direct input. In this paper, we describe how such models can be generated and present our results from two popular video applications with significantly different QoE metrics. We also showcase the use of these models for ISPs to perform QoE-aware traffic management and for the OS to offer an efficient QoE diagnosis service.
Liu, Ying, Han, Yuzheng, Zhang, Ao, Xia, Xiaoyu, Chen, Feifei, Zhang, Mingwei, He, Qiang.  2021.  QoE-aware Data Caching Optimization with Budget in Edge Computing. 2021 IEEE International Conference on Web Services (ICWS). :324—334.
Edge data caching has attracted tremendous attention in recent years. Service providers can consider caching data on nearby locations to provide service for their app users with relatively low latency. The key to enhance the user experience is appropriately choose to cache data on the suitable edge servers to achieve the service providers' objective, e.g., minimizing data retrieval latency and minimizing data caching cost, etc. However, Quality of Experience (QoE), which impacts service providers' caching benefit significantly, has not been adequately considered in existing studies of edge data caching. This is not a trivial issue because QoE and Quality-of-Service (QoS) are not correlated linearly. It significantly complicates the formulation of cost-effective edge data caching strategies under the caching budget, limiting the number of cache spaces to hire on edge servers. We consider this problem of QoE-aware edge data caching in this paper, intending to optimize users' overall QoE under the caching budget. We first build the optimization model and prove the NP-completeness about this problem. We propose a heuristic approach and prove its approximation ratio theoretically to solve the problem of large-scale scenarios efficiently. We have done extensive experiments to demonstrate that the MPSG algorithm we propose outperforms state-of-the-art approaches by at least 68.77%.
Djeachandrane, Abhishek, Hoceini, Said, Delmas, Serge, Duquerrois, Jean-Michel, Mellouk, Abdelhamid.  2022.  QoE-based Situational Awareness-Centric Decision Support for Network Video Surveillance. ICC 2022 - IEEE International Conference on Communications. :335–340.

Control room video surveillance is an important source of information for ensuring public safety. To facilitate the process, a Decision-Support System (DSS) designed for the security task force is vital and necessary to take decisions rapidly using a sea of information. In case of mission critical operation, Situational Awareness (SA) which consists of knowing what is going on around you at any given time plays a crucial role across a variety of industries and should be placed at the center of our DSS. In our approach, SA system will take advantage of the human factor thanks to the reinforcement signal whereas previous work on this field focus on improving knowledge level of DSS at first and then, uses the human factor only for decision-making. In this paper, we propose a situational awareness-centric decision-support system framework for mission-critical operations driven by Quality of Experience (QoE). Our idea is inspired by the reinforcement learning feedback process which updates the environment understanding of our DSS. The feedback is injected by a QoE built on user perception. Our approach will allow our DSS to evolve according to the context with an up-to-date SA.

Murudkar, Chetana V., Gitlin, Richard D..  2019.  QoE-Driven Anomaly Detection in Self-Organizing Mobile Networks Using Machine Learning. 2019 Wireless Telecommunications Symposium (WTS). :1–5.
Current procedures for anomaly detection in self-organizing mobile communication networks use network-centric approaches to identify dysfunctional serving nodes. In this paper, a user-centric approach and a novel methodology for anomaly detection is proposed, where the Quality of Experience (QoE) metric is used to evaluate the end-user experience. The system model demonstrates how dysfunctional serving eNodeBs are successfully detected by implementing a parametric QoE model using machine learning for prediction of user QoE in a network scenario created by the ns-3 network simulator. This approach can play a vital role in the future ultra-dense and green mobile communication networks that are expected to be both self- organizing and self-healing.
Arifeen, F. U., Ali, M., Ashraf, S..  2016.  QoS and security in VOIP networks through admission control mechanism. 2016 13th International Bhurban Conference on Applied Sciences and Technology (IBCAST). :373–380.

With the developing understanding of Information Security and digital assets, IT technology has put on tremendous importance of network admission control (NAC). In NAC architecture, admission decisions and resource reservations are taken at edge devices, rather than resources or individual routers within the network. The NAC architecture enables resilient resource reservation, maintaining reservations even after failures and intra-domain rerouting. Admission Control Networks destiny is based on IP networks through its Security and Quality of Service (QoS) demands for real time multimedia application via advance resource reservation techniques. To achieve Security & QoS demands, in real time performance networks, admission control algorithm decides whether the new traffic flow can be admitted to the network or not. Secure allocation of Peer for multimedia traffic flows with required performance is a great challenge in resource reservation schemes. In this paper, we have proposed our model for VoIP networks in order to achieve security services along with QoS, where admission control decisions are taken place at edge routers. We have analyzed and argued that the measurement based admission control should be done at edge routers which employs on-demand probing parallel from both edge routers to secure the source and destination nodes respectively. In order to achieve Security and QoS for a new call, we choose various probe packet sizes for voice and video calls respectively. Similarly a technique is adopted to attain a security allocation approach for selecting an admission control threshold by proposing our admission control algorithm. All results are tested on NS2 based simulation to evalualate the network performance of edge router based upon network admission control in VoIP traffic.

Khelifi, Hakima, Luo, Senlin, Nour, Boubakr, Moungla, Hassine.  2019.  A QoS-Aware Cache Replacement Policy for Vehicular Named Data Networks. 2019 IEEE Global Communications Conference (GLOBECOM). :1—6.

Vehicular Named Data Network (VNDN) uses Named Data Network (NDN) as a communication enabler. The communication is achieved using the content name instead of the host address. NDN integrates content caching at the network level rather than the application level. Hence, the network becomes aware of content caching and delivering. The content caching is a fundamental element in VNDN communication. However, due to the limitations of the cache store, only the most used content should be cached while the less used should be evicted. Traditional caching replacement policies may not work efficiently in VNDN due to the large and diverse exchanged content. To solve this issue, we propose an efficient cache replacement policy that takes the quality of service into consideration. The idea consists of classifying the traffic into different classes, and split the cache store into a set of sub-cache stores according to the defined traffic classes with different storage capacities according to the network requirements. Each content is assigned a popularity-density value that balances the content popularity with its size. Content with the highest popularity-density value is cached while the lowest is evicted. Simulation results prove the efficiency of the proposed solution to enhance the overall network quality of service.

Roumeliotis, Anargyros J., Panagopoulos, Athanasios D..  2016.  QoS-Based Allocation Cooperative Mechanism for Spectrum Leasing in Overlay Cognitive Radio Networks. Proceedings of the 20th Pan-Hellenic Conference on Informatics. :49:1–49:6.

The cooperative spectrum leasing process between the primary user (PU) and the secondary user (SU) in a cognitive radio network under the overlay approach and the decode and forward (DF) cooperative protocol is studied. Considering the Quality of Service (QoS) provisioning of both users, which participate in a three-phase leasing process, we investigate the maximization of PU's effective capacity subject to an average energy constraint for the SU under a heuristic power and time allocation mechanism. The aforementioned proposed scheme treats with the basic concepts of the convex optimization theory and outperforms a baseline allocation mechanism which is proven by the simulations. Finally, important remarks for the PU's and the SU's performance are extracted for different system parameters.

Mamushiane, Lusani, Shozi, Themba.  2021.  A QoS-based Evaluation of SDN Controllers: ONOS and OpenDayLight. 2021 IST-Africa Conference (IST-Africa). :1–10.
SDN marks a paradigm shift towards an externalized and logically centralized controller, unlike the legacy networks where control and data planes are tightly coupled. The controller has a comprehensive view of the network, offering flexibility to enforce new traffic engineering policies and easing automation. In SDN, a high performance controller is required for efficient traffic management. In this paper, we conduct a performance evaluation of two distributed SDN controllers, namely ONOS and OpenDayLight. Specifically, we use the Mininet emulation environment to emulate different topologies and the D-ITG traffic generator to evaluate aforementioned controllers based on metrics such as delay, jitter and packet loss. The experimental results show that ONOS provides a significantly higher latency, jitter and low packet loss than OpenDayLight in all topologies. We attribute the poor performance of OpenDayLight to its excessive CPU utilization and propose the use of Hyper-threading to improve its performance. This work provides practitioners in the telecoms industry with guidelines towards making informed controller selection decisions
Liu, Siqi, Liu, Shuangyue, Tang, Xizi, Guo, Mengqi, Lu, Yueming, Qiao, Yaojun.  2020.  QPSK-Assisted MIMO Equalization for 800-Gb/s/λ DP-256QAM Systems. 2020 Asia Communications and Photonics Conference (ACP) and International Conference on Information Photonics and Optical Communications (IPOC). :1—3.
A QPSK-assisted MIMO equalization is investigated to compensate bandwidth limitation for 800-Gb/s/λ DP-256QAM systems with only 25G-class optics. Compared with conventional MIMO equalization, the proposed equalization scheme exhibits 1.8-dB OSNR improvement at 15% FEC limit.
Nagata, Daiya, Hayashi, Yu-ichi, Mizuki, Takaaki, Sone, Hideaki.  2021.  QR Bar-Code Designed Resistant against EM Information Leakage. 2021 XXXIVth General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS). :1–4.
A threat of eavesdropping display screen image of information device is caused by unintended EM leakage emanation. QR bar-code is capable of error correction, and its information is possibly read from a damaged screen image from EM leakage. A new design of QR bar-code proposed in this paper uses selected colors in consideration of correlation between the EM wave leakage and display color. Proposed design of QR bar-code keeps error correction of displayed image, and makes it difficult to read information on the eavesdropped image.
Mao, Huajian, Chi, Chenyang, Yu, Jinghui, Yang, Peixiang, Qian, Cheng, Zhao, Dongsheng.  2019.  QRStream: A Secure and Convenient Method for Text Healthcare Data Transferring. 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). :3458–3462.
With the increasing of health awareness, the users become more and more interested in their daily health information and healthcare activities results from healthcare organizations. They always try to collect them together for better usage. Traditionally, the healthcare data is always delivered by paper format from the healthcare organizations, and it is not easy and convenient for data usage and management. They would have to translate these data on paper to digital version which would probably introduce mistakes into the data. It would be necessary if there is a secure and convenient method for electronic health data transferring between the users and the healthcare organizations. However, for the security and privacy problems, almost no healthcare organization provides a stable and full service for health data delivery. In this paper, we propose a secure and convenient method, QRStream, which splits original health data and loads them onto QR code frame streaming for the data transferring. The results shows that QRStream can transfer text health data smoothly with an acceptable performance, for example, transferring 10K data in 10 seconds.
Nazli Choucri, P.S Raghavan, Dr. Sandis Šrāders, Nguyễn Anh Tuấn.  2020.  The Quad Roundtable at the Riga Conference. 2020 Riga Conference. :1–82.
Almost everyone recognizes the emergence of a new challenge in the cyber domain, namely increased threats to the security of the Internet and its various uses. Seldom does a day go by without dire reports and hair raising narratives about unauthorized intrusions, access to content, or damage to systems, or operations. And, of course, a close correlate is the loss of value. An entire industry is around threats to cyber security, prompting technological innovations and operational strategies that promise to prevent damage and destruction. This paper is a collection chapters entitled 1) "Cybersecurity – Problems, Premises, Perspectives," 2) "An Abbreviated Technical Perspective on Cybersecurity," 3) "The Conceptual Underpinning of Cyber Security Studies" 4) "Cyberspace as the Domain of Content," 5) "The Conceptual Underpinning of Cyber Security Studies," 6) "China’s Perspective on Cyber Security," 7) "Pursuing Deterrence Internationally in Cyberspace," 8) "Is Deterrence Possible in Cyber Warfare?" and 9) "A Theoretical Framework for Analyzing Interactions between Contemporary Transnational Activism and Digital Communication."
S. Chen, F. Xi, Z. Liu, B. Bao.  2015.  "Quadrature compressive sampling of multiband radar signals at sub-Landau rate". 2015 IEEE International Conference on Digital Signal Processing (DSP). :234-238.

Sampling multiband radar signals is an essential issue of multiband/multifunction radar. This paper proposes a multiband quadrature compressive sampling (MQCS) system to perform the sampling at sub-Landau rate. The MQCS system randomly projects the multiband signal into a compressive multiband one by modulating each subband signal with a low-pass signal and then samples the compressive multiband signal at Landau-rate with output of compressive measurements. The compressive inphase and quadrature (I/Q) components of each subband are extracted from the compressive measurements respectively and are exploited to recover the baseband I/Q components. As effective bandwidth of the compressive multiband signal is much less than that of the received multiband one, the sampling rate is much less than Landau rate of the received signal. Simulation results validate that the proposed MQCS system can effectively acquire and reconstruct the baseband I/Q components of the multiband signals.

Luo, Linghui, Bodden, Eric, Späth, Johannes.  2019.  A Qualitative Analysis of Android Taint-Analysis Results. 2019 34th IEEE/ACM International Conference on Automated Software Engineering (ASE). :102–114.
In the past, researchers have developed a number of popular taint-analysis approaches, particularly in the context of Android applications. Numerous studies have shown that automated code analyses are adopted by developers only if they yield a good "signal to noise ratio", i.e., high precision. Many previous studies have reported analysis precision quantitatively, but this gives little insight into what can and should be done to increase precision further. To guide future research on increasing precision, we present a comprehensive study that evaluates static Android taint-analysis results on a qualitative level. To unravel the exact nature of taint flows, we have designed COVA, an analysis tool to compute partial path constraints that inform about the circumstances under which taint flows may actually occur in practice. We have conducted a qualitative study on the taint flows reported by FlowDroid in 1,022 real-world Android applications. Our results reveal several key findings: Many taint flows occur only under specific conditions, e.g., environment settings, user interaction, I/O. Taint analyses should consider the application context to discern such situations. COVA shows that few taint flows are guarded by multiple different kinds of conditions simultaneously, so tools that seek to confirm true positives dynamically can concentrate on one kind at a time, e.g., only simulating user interactions. Lastly, many false positives arise due to a too liberal source/sink configuration. Taint analyses must be more carefully configured, and their configuration could benefit from better tool assistance.
Koehler, Henning, Link, Sebastian.  2016.  Qualitative Cleaning of Uncertain Data. Proceedings of the 25th ACM International on Conference on Information and Knowledge Management. :2269–2274.

We propose a new view on data cleaning: Not data itself but the degrees of uncertainty attributed to data are dirty. Applying possibility theory, tuples are assigned degrees of possibility with which they occur, and constraints are assigned degrees of certainty that say to which tuples they apply. Classical data cleaning modifies some minimal set of tuples. Instead, we marginally reduce their degrees of possibility. This reduction leads to a new qualitative version of the vertex cover problem. Qualitative vertex cover can be mapped to a linear-weighted constraint satisfaction problem. However, any off-the-shelf solver cannot solve the problem more efficiently than classical vertex cover. Instead, we utilize the degrees of possibility and certainty to develop a dedicated algorithm that is fixed parameter tractable in the size of the qualitative vertex cover. Experiments show that our algorithm is faster than solvers for the classical vertex cover problem by several orders of magnitude, and performance improves with higher numbers of uncertainty degrees.

Bradley, Cerys, Stringhini, Gianluca.  2019.  A Qualitative Evaluation of Two Different Law Enforcement Approaches on Dark Net Markets. 2019 IEEE European Symposium on Security and Privacy Workshops (EuroS PW). :453—463.

This paper presents the results of a qualitative study on discussions about two major law enforcement interventions against Dark Net Market (DNM) users extracted from relevant Reddit forums. We assess the impact of Operation Hyperion and Operation Bayonet (combined with the closure of the site Hansa) by analyzing posts and comments made by users of two Reddit forums created for the discussion of Dark Net Markets. The operations are compared in terms of the size of the discussions, the consequences recorded, and the opinions shared by forum users. We find that Operation Bayonet generated a higher number of discussions on Reddit, and from the qualitative analysis of such discussions it appears that this operation also had a greater impact on the DNM ecosystem.

Rahkema, Kristiina.  2021.  Quality analysis of mobile applications with special focus on security aspects. 2021 36th IEEE/ACM International Conference on Automated Software Engineering (ASE). :1087–1089.
Smart phones and mobile apps have become an essential part of our daily lives. It is necessary to ensure the quality of these apps. Two important aspects of code quality are maintainability and security. The goals of my PhD project are (1) to study code smells, security issues and their evolution in iOS apps and frameworks, (2) to enhance training and teaching using visualisation support, and (3) to support developers in automatically detecting dependencies to vulnerable library elements in their apps. For each of the three tools, dedicated tool support will be provided, i.e., GraphifyEvolution, VisualiseEvolution, and DependencyEvolution respectively. The tool GraphifyEvolution exists and has been applied to analyse code smells in iOS apps written in Swift. The tool has a modular architecture and can be extended to add support for additional languages and external analysis tools. In the remaining two years of my PhD studies, I will complete the other two tools and apply them in case studies with developers in industry as well as in university teaching.
Zaidan, Firas, Hannebauer, Christoph, Gruhn, Volker.  2016.  Quality Attestation: An Open Source Pattern. Proceedings of the 21st European Conference on Pattern Languages of Programs. :2:1–2:7.

A number of small Open Source projects let independent providers measure different aspects of their quality that would otherwise be hard to see. This paper describes this observation as the pattern Quality Attestation. Quality Attestation belongs to a family of Open Source patterns written by various authors.

Liang, Danwei, An, Jian, Cheng, Jindong, Yang, He, Gui, Ruowei.  2018.  The Quality Control in Crowdsensing Based on Twice Consensuses of Blockchain. Proceedings of the 2018 ACM International Joint Conference and 2018 International Symposium on Pervasive and Ubiquitous Computing and Wearable Computers. :630–635.
In most crowdsensing systems, the quality of the collected data is varied and difficult to evaluate while the existing crowdsensing quality control methods are mostly based on a central platform, which is not completely trusted in reality and results in fraud and other problems. To solve these questions, a novel crowdsensing quality control model is proposed in this paper. First, the idea of blockchain is introduced into this model. The credit-based verifier selection mechanism and twice consensuses are proposed to realize the non-repudiation and non-tampering of information in crowdsensing. Then, the quality grading evaluation (QGE) is put forward, in which the method of truth discovery and the idea of fuzzy theories are combined to evaluate the quality of sensing data, and the garbled circuit is used to ensure that evaluation criteria can not be leaked. Finally, the Experiments show that our model is feasible in time and effective in quality evaluation.
Prechelt, Lutz, Schmeisky, Holger, Zieris, Franz.  2016.  Quality Experience: A Grounded Theory of Successful Agile Projects Without Dedicated Testers. Proceedings of the 38th International Conference on Software Engineering. :1017–1027.

Context: While successful conventional software development regularly employs separate testing staff, there are successful agile teams with as well as without separate testers. Question: How does successful agile development work without separate testers? What are advantages and disadvantages? Method: A case study, based on Grounded Theory evaluation of interviews and direct observation of three agile teams; one having separate testers, two without. All teams perform long-term development of parts of e-business web portals. Results: Teams without testers use a quality experience work mode centered around a tight field-use feedback loop, driven by a feeling of responsibility, supported by test automation, resulting in frequent deployments. Conclusion: In the given domain, hand-overs to separate testers appear to hamper the feedback loop more than they contribute to quality, so working without testers is preferred. However, Quality Experience is achievable only with modular architectures and in suitable domains.