Marxist history and schooling: Beyond economism

Marxist history emphasises the linkage between economic production, social institutions and everyday life. Critics of Marxism claim that its analysis of schooling is simplistic, functional and deterministic The first part of this paper examines whether Marxist historical practice was in fact deterministic. It offers a non-reductionist and non-economistic reading of Marx's historical methodology. The second section moves on to consider some of the ways in which post-structuralist theorising can 'loosen-up' and revitalise mechanistic Marxist interpretations of the history of schooling

Labor market regulations and trade patterns : the panel data analysis within a modified ricardian setting

The paper focuses on the question of how labor market regulations can affect a country’s competitive position in international trade and international trade patterns. The analysis shows that differences in labor market flexibility between countries affect their competitive positions in international markets and can serve as an independent cause of international trade. It is argued that an increase in labor market flexibility may change the relative price of goods within the country making it more competitive in international markets for commodities with uncertain demand. Changes in relative prices can alter countries’ comparative advantage and thus international trade patterns. Furthermore, it is shown that due to the differences in relative prices resulting from different labor market regulations, international trade between countries can be observed even if they are identical in all respects (e.g., labor productivity and production technology). Data reveal that a country with a more flexible labor market has comparative advantage in, and tends to export, goods with more variable demand (e.g., fashionable clothes, seasonal toys), while a country with a more rigid labor market has a comparative advantage in, and tends to export, commodities with more stable demand.info:eu-repo/semantics/publishedVersio

On Non-Parallelizable Deterministic Client Puzzle Scheme with Batch Verification Modes

A (computational) client puzzle scheme enables a client to prove to a server that a certain amount of computing resources (CPU cycles and/or Memory look-ups) has been dedicated to solve a puzzle. Researchers have identified a number of potential applications, such as constructing timed cryptography, fighting junk emails, and protecting critical infrastructure from DoS attacks. In this paper, we first revisit this concept and formally define two properties, namely deterministic computation and parallel computation resistance. Our analysis show that both properties are crucial for the effectiveness of client puzzle schemes in most application scenarios. We prove that the RSW client puzzle scheme, which is based on the repeated squaring technique, achieves both properties. Secondly, we introduce two batch verification modes for the RSW client puzzle scheme in order to improve the verification efficiency of the server, and investigate three methods for handling errors in batch verifications. Lastly, we show that client puzzle schemes can be integrated with reputation systems to further improve the effectiveness in practice

Game-Theoretic Pricing and Selection with Fading Channels

We consider pricing and selection with fading channels in a Stackelberg game framework. A channel server decides the channel prices and a client chooses which channel to use based on the remote estimation quality. We prove the existence of an optimal deterministic and Markovian policy for the client, and show that the optimal policies of both the server and the client have threshold structures when the time horizon is finite. Value iteration algorithm is applied to obtain the optimal solutions for both the server and client, and numerical simulations and examples are given to demonstrate the developed result.Comment: 6 pages, 4 figures, accepted by the 2017 Asian Control Conferenc

Rethinking State-Machine Replication for Parallelism

State-machine replication, a fundamental approach to designing fault-tolerant services, requires commands to be executed in the same order by all replicas. Moreover, command execution must be deterministic: each replica must produce the same output upon executing the same sequence of commands. These requirements usually result in single-threaded replicas, which hinders service performance. This paper introduces Parallel State-Machine Replication (P-SMR), a new approach to parallelism in state-machine replication. P-SMR scales better than previous proposals since no component plays a centralizing role in the execution of independent commands---those that can be executed concurrently, as defined by the service. The paper introduces P-SMR, describes a "commodified architecture" to implement it, and compares its performance to other proposals using a key-value store and a networked file system

Trivalent Graph isomorphism in polynomial time

It's important to design polynomial time algorithms to test if two graphs are isomorphic at least for some special classes of graphs. An approach to this was presented by Eugene M. Luks(1981) in the work \textit{Isomorphism of Graphs of Bounded Valence Can Be Tested in Polynomial Time}. Unfortunately, it was a theoretical algorithm and was very difficult to put into practice. On the other hand, there is no known implementation of the algorithm, although Galil, Hoffman and Luks(1983) shows an improvement of this algorithm running in $O(n^3 \log n)$. The two main goals of this master thesis are to explain more carefully the algorithm of Luks(1981), including a detailed study of the complexity and, then to provide an efficient implementation in SAGE system. It is divided into four chapters plus an appendix.Comment: 48 pages. It is a Master Thesi

Optimistic Parallel State-Machine Replication

State-machine replication, a fundamental approach to fault tolerance, requires replicas to execute commands deterministically, which usually results in sequential execution of commands. Sequential execution limits performance and underuses servers, which are increasingly parallel (i.e., multicore). To narrow the gap between state-machine replication requirements and the characteristics of modern servers, researchers have recently come up with alternative execution models. This paper surveys existing approaches to parallel state-machine replication and proposes a novel optimistic protocol that inherits the scalable features of previous techniques. Using a replicated B+-tree service, we demonstrate in the paper that our protocol outperforms the most efficient techniques by a factor of 2.4 times

Interest-Based Access Control for Content Centric Networks (extended version)

Content-Centric Networking (CCN) is an emerging network architecture designed to overcome limitations of the current IP-based Internet. One of the fundamental tenets of CCN is that data, or content, is a named and addressable entity in the network. Consumers request content by issuing interest messages with the desired content name. These interests are forwarded by routers to producers, and the resulting content object is returned and optionally cached at each router along the path. In-network caching makes it difficult to enforce access control policies on sensitive content outside of the producer since routers only use interest information for forwarding decisions. To that end, we propose an Interest-Based Access Control (IBAC) scheme that enables access control enforcement using only information contained in interest messages, i.e., by making sensitive content names unpredictable to unauthorized parties. Our IBAC scheme supports both hash- and encryption-based name obfuscation. We address the problem of interest replay attacks by formulating a mutual trust framework between producers and consumers that enables routers to perform authorization checks when satisfying interests from their cache. We assess the computational, storage, and bandwidth overhead of each IBAC variant. Our design is flexible and allows producers to arbitrarily specify and enforce any type of access control on content, without having to deal with the problems of content encryption and key distribution. This is the first comprehensive design for CCN access control using only information contained in interest messages.Comment: 11 pages, 2 figure

Dynamic Traitor Tracing for Arbitrary Alphabets: Divide and Conquer

We give a generic divide-and-conquer approach for constructing collusion-resistant probabilistic dynamic traitor tracing schemes with larger alphabets from schemes with smaller alphabets. This construction offers a linear tradeoff between the alphabet size and the codelength. In particular, we show that applying our results to the binary dynamic Tardos scheme of Laarhoven et al. leads to schemes that are shorter by a factor equal to half the alphabet size. Asymptotically, these codelengths correspond, up to a constant factor, to the fingerprinting capacity for static probabilistic schemes. This gives a hierarchy of probabilistic dynamic traitor tracing schemes, and bridges the gap between the low bandwidth, high codelength scheme of Laarhoven et al. and the high bandwidth, low codelength scheme of Fiat and Tassa.Comment: 6 pages, 1 figur