A study in how the ink set, solid ink density and screening method influence the color gamut in four color process printing

The number of possible reproducible colors in a printing method is called the color gamut. This gamut is the range of colors around the spectrum and from light to dark that are available in the process. Previous research has found that the three parameters, spectral reflectance of the ink, solid ink density level and screening method, all influence the gamut in process color printing. This thesis evaluated how much these parameters change the color gamut both as individual parameters and in combination. A test target with 168 patches in the most saturated combinations of cyan, magenta, yellow and black was printed and measured with a spectrophotometer. The three coordinates L*, a* and b* for each patch in the target was plotted in the CIELAB space. Connecting these points forms a three dimensional object, the color gamut volume. By calculating the volume of this object the number of CIELAB combinations that can be reproduced in the system was derived. The pressrun was made at three levels of solid ink density and the targets were screened using frequency and amplitude modulated screening. The print was made on the six color Heidelberg Speedmaster 72 sheet fed lithography press at School of Printing Management and Science, Rochester Institute of Technology. The inks that were used in the test print are the Naturalith process cyan, magenta, yellow and black from Sun Chemical. In addition to these, a fluorescent magenta and yellow ink from DayGlo\u27s ink series Starfire were used. These alternative magenta and yellow inks were printed with the Naturalith cyan and black. In this way two four color process combinations were evaluated with only six inks. The prints where made on a glossy coated paper, Centura Gloss from Consolidated Paper Inc. The result show that: Fluorescent inks can be used in process color printing and that they produced a color gamut that reproduce light and more colorful colors than normal process colors, while dark colors were reproduced with lower colorfulness. The fluorescent inks that were used are semi transparent and can not yield a dark black when printed on top of black. The solution is to use a high degree of under color removal and or to printing black as the last down ink. High solid ink densities was found to increase the color gamut for both ink sets. Frequency modulated screening was found to reproduce a color gamut with significantly higher gamut for the normal sheet fed inks, while no increase could be found for the fluorescent inks. By using frequency modulated screening and increasing the solid ink density when using normal sheet fed ink, the color gamut could be increased about 30 percent compared to amplitude modulated screening and SWOP solid ink densities. The Silicon Graphics based 3D software Explorer was found to be a very useful tool when determining the shape of the color gamut

Approximation Algorithms for Geometric Networks

The main contribution of this thesis is approximation algorithms for several computational geometry problems. The underlying structure for most of the problems studied is a geometric network. A geometric network is, in its abstract form, a set of vertices, pairwise connected with an edge, such that the weight of this connecting edge is the Euclidean distance between the pair of points connected. Such a network may be used to represent a multitude of real-life structures, such as, for example, a set of cities connected with roads. Considering the case that a specific network is given, we study three separate problems. In the first problem we consider the case of interconnected `islands' of well-connected networks, in which shortest paths are computed. In the second problem the input network is a triangulation. We efficiently simplify this triangulation using edge contractions. Finally, we consider individual movement trajectories representing, for example, wild animals where we compute leadership individuals. Next, we consider the case that only a set of vertices is given, and the aim is to actually construct a network. We consider two such problems. In the first one we compute a partition of the vertices into several subsets where, considering the minimum spanning tree (MST) for each subset, we aim to minimize the largest MST. The other problem is to construct a $t$-spanner of low weight fast and simple. We do this by first extending the so-called gap theorem. In addition to the above geometric network problems we also study a problem where we aim to place a set of different sized rectangles, such that the area of their corresponding bounding box is minimized, and such that a grid may be placed over the rectangles. The grid should not intersect any rectangle, and each cell of the grid should contain at most one rectangle. All studied problems are such that they do not easily allow computation of optimal solutions in a feasible time. Instead we consider approximation algorithms, where near-optimal solutions are produced in polynomial time. In addition to the above geometric network problems we also study a problem where we aim to place a set of different sized rectangles, such that the area of their corresponding bounding box is minimized, and such that a grid may be placed over the rectangles. The grid should not intersect any rectangle, and each cell of the grid should contain at most one rectangle. All studied problems are such that they do not easily allow computation of optimal solutions in a feasible time. Instead we consider approximation algorithms, where near-optimal solutions are produced in polynomial time

Forecasting the fast and frugal way: A study of performance and information-processing strategies of experts and non-experts when predicting the World Cup 2002 in soccer

This paper investigates forecasting performance and judgmental processes of experts and non-experts in soccer. Two circumstances motivated the paper: (i) little is known about how accurately experts predict sports events, and (ii) recent research on human judgment suggests that ignorance-based decision-strategies may be reliable. About 250 participants with different levels of knowledge of soccer took part in a survey and predicted the outcome of the first round of World Cup 2002. It was found that the participating experts (i.e., sport journalists, soccer fans, and soccer coaches) were not more accurate than the non-experts. Experts overestimated their performance and were overconfident. While the experts claimed to have relied on analytical approaches and much information, participants with limited knowledge stated that their forecasts were based upon recognition and few pieces of information. The paper concludes that a recognition-based strategy seems to be appropriate when forecasting worldwide soccer events.Expert predictions; Information use; Judgmental forecasting; Overconfidence; Recognition heuristic; Sports forecasting

Rate-Equivocation Optimal Spatially Coupled LDPC Codes for the BEC Wiretap Channel

We consider transmission over a wiretap channel where both the main channel and the wiretapper's channel are Binary Erasure Channels (BEC). We use convolutional LDPC ensembles based on the coset encoding scheme. More precisely, we consider regular two edge type convolutional LDPC ensembles. We show that such a construction achieves the whole rate-equivocation region of the BEC wiretap channel. Convolutional LDPC ensemble were introduced by Felstr\"om and Zigangirov and are known to have excellent thresholds. Recently, Kudekar, Richardson, and Urbanke proved that the phenomenon of "Spatial Coupling" converts MAP threshold into BP threshold for transmission over the BEC. The phenomenon of spatial coupling has been observed to hold for general binary memoryless symmetric channels. Hence, we conjecture that our construction is a universal rate-equivocation achieving construction when the main channel and wiretapper's channel are binary memoryless symmetric channels, and the wiretapper's channel is degraded with respect to the main channel.Comment: Working pape

On the geometry and topology of initial data sets with horizons

We study the relationship between initial data sets with horizons and the existence of metrics of positive scalar curvature. We define a Cauchy Domain of Outer Communications (CDOC) to be an asymptotically flat initial set $(M, g, K)$ such that the boundary $\partial M$ of $M$ is a collection of Marginally Outer (or Inner) Trapped Surfaces (MOTSs and/or MITSs) and such that $M\setminus \partial M$ contains no MOTSs or MITSs. This definition is meant to capture, on the level of the initial data sets, the well known notion of the domain of outer communications (DOC) as the region of spacetime outside of all the black holes (and white holes). Our main theorem establishes that in dimensions $3\leq n \leq 7$, a CDOC which satisfies the dominant energy condition and has a strictly stable boundary has a positive scalar curvature metric which smoothly compactifies the asymptotically flat end and is a Riemannian product metric near the boundary where the cross sectional metric is conformal to a small perturbation of the initial metric on the boundary $\partial M$ induced by $g$. This result may be viewed as a generalization of Galloway and Schoen's higher dimensional black hole topology theorem \cite{GS06} to the exterior of the horizon. We also show how this result leads to a number of topological restrictions on the CDOC, which allows one to also view this as an extension of the initial data topological censorship theorem, established in \cite{EGP13} in dimension $n=3$, to higher dimensions.Comment: Final version. To appear in Asian Journal of Mathematic

Konsumenter om märken på mat

Miljöproblemen har blivit alltmer komplexa och en mängd olika budskap riktas till konsumenterna i deras val av mat. En rik flora av märkningar används för att informera om miljöriktiga och klimatsmarta inköp. En synpunkt som kom fram i samband med de konsumentundersökningar som publicerats i tidigare faktablad kring frukt, grönsaker och potatis var att konsumenten har svårt att skilja mellan olika budskap och märkningar som finns på frukt och grönt och på livsmedel i allmänhet. I detta faktablad presenteras en enkätstudie med syfte att testa konsumenters intresse för och kännedom om märken, logotyper, som förekommer på den svenska marknaden, med fokus på miljömärkningen. Produktmärkningar på livsmedel är viktiga för konsumenterna i studien. Resultatet visar också att kännedomen och kunskapen om miljömärkningen är relativt låg, med undantag för KRAV, som de flesta känner till. Sju av tio säger sig veta vad KRAV står för, men när frågan ställs direkt till ett trettiotal av konsumenterna kan knappt hälften ge en godtagbar definition. Trots en hög igenkänningsgrad är kunskapen relativt låg om Änglamark, som har angivist som Sveriges grönaste varumärke. Sju av tio känner till Svenskt Sigill men knappt tre av tio tror sig veta vad det står för och få kan ge en egen godtagbar beskrivning. Det råder en viss förvirring kring nuvarande märkning och man blandar ihop miljömärken, hälsomärken och etisk märkning. Nyckelhålet är ett framgångsrikt hälsomärke och två tredjedelar känner också till ICA Gott liv. Fair Trade känns igen av knappt sex av tio. Dagligvaruhandeln skulle kunna vägleda konsumenten till klimatsmarta livsmedelsval genom olika kommunikationsmedel och i studien anger en majoritet att det vore bra med ett märke som graderar i stället för att certifiera. Konsumenterna tittar lika mycket på innehållsförteckningar som på märken. Ett alternativ till logotyper och ”trafikljus” är innehållsdeklarationer med mer detaljerad information om produktionsmetoder och miljöeffekter. Detta förutsätter att det finns objektiv information som konsumenten kan tolka. Även om mer information alltid antas vara bra kan man ändå ställa sig frågan om konsumenterna inte till sist går efter relativt enkla signaler. Det finns en stor tilltro till deras förmåga att fatta rationella beslut baserade på den information som märkningen kommunicerar, inte minst bland avsändarna till de olika märkena. Dessa kan förhoppningsvis finna resultaten intressanta i sitt strategiska utvecklingsarbete. Den utbredda okunskap som resultaten visar på aktualiserar också frågan om statens roll i samband med informationsspridning och produktmärkning

Performance Analysis and Design of Two Edge Type LDPC Codes for the BEC Wiretap Channel

We consider transmission over a wiretap channel where both the main channel and the wiretapper's channel are Binary Erasure Channels (BEC). We propose a code construction method using two edge type LDPC codes based on the coset encoding scheme. Using a standard LDPC ensemble with a given threshold over the BEC, we give a construction for a two edge type LDPC ensemble with the same threshold. If the given standard LDPC ensemble has degree two variable nodes, our construction gives rise to degree one variable nodes in the code used over the main channel. This results in zero threshold over the main channel. In order to circumvent this problem, we numerically optimize the degree distribution of the two edge type LDPC ensemble. We find that the resulting ensembles are able to perform close to the boundary of the rate-equivocation region of the wiretap channel. There are two performance criteria for a coding scheme used over a wiretap channel: reliability and secrecy. The reliability measure corresponds to the probability of decoding error for the intended receiver. This can be easily measured using density evolution recursion. However, it is more challenging to characterize secrecy, corresponding to the equivocation of the message for the wiretapper. M\'easson, Montanari, and Urbanke have shown how the equivocation can be measured for a broad range of standard LDPC ensembles for transmission over the BEC under the point-to-point setup. By generalizing the method of M\'easson, Montanari, and Urbanke to two edge type LDPC ensembles, we show how the equivocation for the wiretapper can be computed. We find that relatively simple constructions give very good secrecy performance and are close to the secrecy capacity. However finding explicit sequences of two edge type LDPC ensembles which achieve secrecy capacity is a more difficult problem. We pose it as an interesting open problem.Comment: submitted to IEEE Transactions on Information Theory. Updated versio

Proliferation of Ewing sarcoma cell lines is suppressed by the receptor tyrosine kinase inhibitors gefitinib and vandetanib

<p>Abstract</p> <p>Background</p> <p>Tyrosine kinase inhibitors (TKIs) have gained much attention in recent years as targeted agents for the treatment of a wide range of human cancers. We have investigated the effect of the TKIs gefitinib and vandetanib on tumor cell lines derived from Ewing sarcoma, a highly malignant tumor affecting bone and soft tissue in children and young adults. Gefitinib is an inhibitor of epidermal growth factor receptor tyrosine kinase activity (EGFR) and vandetanib selectively targets vascular endothelial growth factor receptor-2 (VEGFR-2) with additional activity against VEGFR-3, EGFR and RET kinase receptors.</p> <p>Results</p> <p>Two Ewing sarcoma cell lines investigated showed high levels of nuclear EGFR expression as well as moderate expression in plasma membrane and cytoplasm. When treated with concentrations of 5 μM and more of either gefitinib or vandetanib, we observed a significant decrease in cell proliferation. However, there were no detectable changes in p44/42 MAPK and Akt-1 phosphorylation, or in the expression of cyclin D1 or c-Myc following gefitinib or vandetanib treatment.</p> <p>Conclusion</p> <p>We conclude that Ewing sarcoma tumor cell proliferation is not highly sensitive to inhibition of EGFR signaling alone or the simultaneous inhibition of VEGFR receptors, EGFR and RET kinase. Decreased tumor cell proliferation could be achieved with gefitinib and vandetanib, but only at higher doses where non-specific effects of the compounds may be overriding. As Ewing tumor cells do not seem to depend on EGFR and VEGFR pathways for survival, other key factors in the cellular signaling of Ewing sarcoma should be targeted in order to obtain a potent therapeutic response.</p