A New Algorithm for Solving Ring-LPN with a Reducible Polynomial

The LPN (Learning Parity with Noise) problem has recently proved to be of great importance in cryptology. A special and very useful case is the RING-LPN problem, which typically provides improved efficiency in the constructed cryptographic primitive. We present a new algorithm for solving the RING-LPN problem in the case when the polynomial used is reducible. It greatly outperforms previous algorithms for solving this problem. Using the algorithm, we can break the Lapin authentication protocol for the proposed instance using a reducible polynomial, in about 2^70 bit operations

Using Self-employment as Proxy for Entrepreneurship: Some Empirical Caveats

Research on entrepreneurship has received an increased amount of interest in recent years, with self-employment being used as the most common proxy for “entrepreneurship” in empirical studies. However, there are various ways of defining selfemployment, making it a somewhat dubious proxy. This may flaw the analysis, especially in cross-country studies, since the documentation of data often is insufficient and difficult to access due to language barriers. We present an analysis of Swedish self-employment data. We show that the measurement of self-employment has changed over time to noticeably affect the reported number of self-employed in the two major statistical sources on self-employment. The reported development of self-employment sometimes differs diametrically depending on source. Sweden is occasionally erroneously reported to show the largest increase in selfemployment in cross-country studies. Our study mimics the results of other country-specific analyses and we conclude that well-grounded conclusions require that the advantages and disadvantages of different statistical sources are recognized.Labor Force Survey; RAMS; self-employed; self employment; entrepreneurship

Using Self-employment as Proxy for Entrepreneurship: Some Empirical Caveats

Research on entrepreneurship has received an increased amount of interest in recent years, with self-employment being used as the most common proxy for “entrepreneurship” in empirical studies. However, there are various ways of defining self-employment, making it a somewhat dubious proxy. This may flaw the analysis, especially in cross-country studies, since the documentation of data often is insufficient and difficult to access due to language barriers. We present an analysis of Swedish self-employment data. We show that the measurement of self-employment has changed over time to noticeably affect the reported number of self-employed in the two major statistical sources on self-employment. The reported development of self-employment sometimes differs diametrically depending on source. Sweden is occasionally erroneously reported to show the largest increase in self-employment in cross-country studies. Our study mimics the results of other country-specific analyses and we conclude that well-grounded conclusions require that the advantages and disadvantages of different statistical sources are recognized.Labor Force Survey; RAMS; Self-employed; Self-employment; Entrepreneurship

Family Business, Employment, and GDP

We analyze the proportion of family business and its contribution to employment and gross domestic product (GDP). Our analysis adds to the literature by including all listed firms and by investigating a longer period than has heretofore been reported. The main contribution is to extend the analysis to include all firms in the economy using census data. Our study is devoted to the case of Sweden. Family business makes up half of the listed firms, and three quarters of all firms, accounting for one-fourth of total employment, and one-fifth of GDP. Their importance has increased during the period studied.Family Firms; Employment; GDP; Sweden; Ownership

Ownership and High-Growth Firms

Empirical studies demonstrate that most net job-growth originates from a small number of high-growth firms (HGFs). The purpose of this paper is to analyze whether firm ownership – family, or private non-family – matters for being a HGF, using data covering all firms in Sweden during 1993-2006. Firm growth is measured in terms of absolute employment growth, relative employment growth and as a combination of absolute and relative employment growth (the so-called Birch-index). We find that family ownership decreases the probability of exhibiting high growth. Changing ownership from family to private non family increases the probability of being a HGF, whereas a change from private non-family to family ownership decreases the probability of being a HGF. The results are robust, irrespective of measurement of firm growth, suggesting that ownership and changes in ownership are important determinants of rapid firm growth.high-growth firms; gazelles; firm growth; firm ownership; family firms; rapid firm growth

Vägledning i naturen

Idag utövar nästan varje svensk friluftslivsaktiviteter. Människans relation till naturen har genom tiderna förändrats och samtidens urbanisering kan distansera människan ifrån dess sammanhang. I vår tids stora klimatutmaning blir relationen till det vi vill bevara och rädda mer ansträngd och komplex när kunskapen och självklarheten om naturen marginaliseras. Sverige har sedan 70-talet uppfört så kallade naturum i närheten av upplevelsevärd natur i syfte att föra människor närmre den gröna miljön. Ur aspekten naturvägledning kan dock denna port till naturen ses som stängd. Den här uppsatsen syftar till att placera naturums sociala värden i en utomhusmiljö. Därmed presenteras ett gestaltningsförslag som alternativ till naturum i ett kunskaps- och undervisningssyfte. Undersökningen av ämnet grundas på Naturvårdsverket rapport Riktlinjer för naturum vilken är utgångspunkten för de aspekter som litteraturbakgrunden behandlar, såsom miljöpsykologi, naturvägledning och utomhuspedagogik. För att pröva teorierna och få inspiration omfattar metoden även en referensstudie av besökscentret i Hälleskogsbrännans naturreservat i Västmanland, som presenteras i resultatet. Vidare omfattar resultatet inventering och analys av det stadsnära naturområdet vid Kung Björns hög i Uppsala, som är platsen för gestaltningen. Resultatet är en platsspecifik slinga som med enkla medel vägleder människan genom landskapet. Slutligen diskuteras metod, litteratur, gestaltningens tillämpning av teorier och samspelet mellan landskapsarkitektur och naturvägledning.Today, almost every swede performs outdoor leisure activities. Humans relationship with nature has changed over time and contemporary urbanization can distance humans from their context. In today's major climate challenge, the relationship to what we want to preserve and protect becomes more strained and complex when the knowledge of nature is marginalized. Since the 70s, Sweden has constructed so-called naturum to facilitate the experience of nature in order to bring people closer to the green environment. However, from the aspect of nature guidance, this gate to nature can be seen as closed. This thesis aims to relocate the social values of naturum in an outdoor environment. Thus, a design proposal is presented as an alternative to naturum for a knowledge and educational purpose. The study of the subject is based on the Swedish Environmental Protection Agency's report Riktlinjer för naturum (Guidelines for naturum), which leads to the aspects covered by the literature background, such as environmental psychology, nature guidance and outdoor pedagogics. To examine the theories and acquire inspiration, the method also includes a reference study of the visit center in the nature reserve Hälleskogsbrännan in Västmanland, which is presented in the results. Furthermore, the result includes inventory and analysis of the peri-urban nature area at King Björn's mound in Uppsala, which is the site for the design. The result is a site-specific landscape trail that guides people with simple means. Lastly, the method, literature, the application of the theories and the interaction between landscape architecture and nature guidance are discussed

The Future Climate Moisture Susceptibility of Wall Assemblies: Analysis Based on Monte Carlo Simulation Using a Simplified Deterministic Hygrothermal Simulation Model

A newly developed generic algorithm to assess moisture susceptibility of simplified wall assemblies has been developed within the CIB-W080 WG 2. This group is focusing on guidelines for design for durability of building envelopes. The algorithm is implemented in a publicly available Matlab code. A simplified wall assembly consisting of up to four material elements is considered. Optional vapor retarder and thermal resistances are located between the elements. In this paper modelling of a ventilated cladding is implemented. Using the simplified numerical model, a probability‐based risk analysis using the Monte Carlo method is demonstrated. The risk assessment of the wall assembly considers the interior and exterior climatic load. The moisture transport mechanism accounted for in the analysis is diffusion. The rain load is assumed to be transferred directly to a chosen outer susceptible material element in the construction. An insulated wooden wall structure is analyzed and the probability distribution of the time of wetness is presented for cases using sequence of 31 consecutive climatic years, randomly varying indoor moisture excess, indoor temperature and driving rain leakages