2,313 research outputs found
Multiplicity, Invariants and Tensor Product Decomposition of Tame Representations of U(\infty)
The structure of r-fold tensor products of irreducible tame representations
of the inductive limit U(\infty) of unitary groups U(n) are are described,
versions of contragredient representations and invariants are realized on
Bargmann-Segal-Fock spaces.Comment: 48 pages, LaTeX file, to appear in J. Math. Phy
Een pleidooi voor duurzame diplomatie
In een recent verschenen notitie van de Adviesraad Internationale Vraagstukken wordt een pleidooi gehouden voor 'diplomatie van duurzame ontwikkeling'. Het Nederlandse buitenlandse beleid heeft de laatste jaren sterk ingezet op zogenaamde 'economische diplomatie'. Daarmee lijkt een stap gezet te zijn in de richting van een vorm van diplomatie waarbij het Nederlandse economische belang meer centraal staat. Maar welke belangen zijn dat dan? Naast bezuinigingen worden tegelijkertijd nieuwe beleidsinstrumenten ontwikkeld waarvan de effectiviteit nog bewezen moet worden. Deze dubbelslag vertegenwoordigt een (her)oriëntatie op de diplomatieke inzet van Nederland, welke vooral gevolgen lijkt te hebben voor het ontwikkelingsbeleid. Dat levert verhitte debatten op, zeker wanneer de financiële consequenties van dit beleid voor bestaande belangengroepen duidelijk worden. Deze discussie is weinig productief zolang een meer integrale en strategische visie op de beoogde diplomatieke inzet niet gedeeld wordt. Wat kan derhalve als gezamenlijk (bilateraal) belang van zowel Nederland als de ontvangende landen worden gezien? Juist voor een klein land als Nederland is een integrale ' slimme, pragmatische, maar ook doelgerichte en duurzame - benadering essentieel. Een preciezere framing van het beleid is daarom gewenst: van economische diplomatie, waarbij het er niet toe doet welke handelsstromen op gang worden gebracht (zolang het maar veel is), naar duurzame diplomatie, ofwel 'diplomatie van duurzame ontwikkeling', waarbij veel meer wordt nagedacht over de kwaliteit, de doelstelling en de lange termijn invulling van deze relaties
Mixtures of tails in clustered automobile collision claims
Knowledge of the tail shape of claim distributions provides important actuarial information. This paper discusses how two techniques commonly used in assessing the most appropriate underlying distribution can be usefully combined. The maximum likelihood approach is theoretically appealing since it is preferable to many other estimators in the sense of best asymptotic normality. Likelihood based tests are, however, not always capable to discriminate among non-nested classes of distributions. Extremal value theory offers an attractive tool to overcome this problem. It shows that a much larger set of distributions is nested in their tails by the so-called tail parameter. This paper shows that both estimation strategies can be usefully combined when the data generating process is characterized by strong clustering in time and size. We find that the extreme value theory is a useful starting point in detecting the appropriate distribution class. Once that has been achieved, the likelihood-based EM-algorithm is proposed to capture the clustering phenomena. Clustering is particularly pervasive in actuarial data. An empirical application to a four-year data set of Dutch automobile collision claims is therefore used to illustrate the approach
Promoting Self-Directed Learning in Simulation-Based Discovery Learning Environments Through Intelligent Support
Contribution analysis of a Bolivian innovation grant fund: mixing methods to verify relevance, efficiency and effectiveness
We used contribution analysis to verify the key assumption in the intervention logic of an innovation fund in Bolivia directed to economic farmer organisations to develop value-added activities. We focused the research on three sub-components of the intervention logic: relevance of the farmer groups for local economic development, effectiveness of the fund in strengthening these group, and efficiency of the grant allocation mechanism. We used a case-based comparative analysis to assess effectiveness: improved market access for members, strengthened organisational capacities and the capacity to pay organisational costs. We showed that the grants to already well-endowed organisations were particularly unsuccessful
Perencanaan Jembatan Pelengkung Type Throught Arch Desa Korek, Kec. Ambawang, Kab. Kubu Raya (Provinsi Kalimantan Barat)
Jembatan merupakan suatu struktur bangunan yang berfungsi untuk menyatukan jalan yang terputus oleh rintangan, misalnya sungai, rawa, dll. Dalam penyusunan Tugas Akhir ini direncanakan jembatan pelengkung type Throught Arch di Desa Korek, Kec. Ambawang, Kab. Kubu Raya (Ka-Bar). Tahap awal perencanaan adalah perhitungan struktur atas yang meliputi pipa sandaran, tiang sandaran, dinding penahan, trotoar, pelat lantai kendaraan, gelegar memanjang, gelegar melintang, hubungan gelegar memanjang terhadap gelegar melintang dan sekaligus perhitungan penghubung geser (shear connector). Memasuki tahap konstruksi utama, dilakukan perhitungan beban-beban yang bekerja kemudian dianalisa dengan menggunakan program komputer. Setelah didapat gaya-gaya dalam yang bekerja dilakukan perhitungan kontrol tegangan dan perhitungan sambungan. Bersamaan dilakukan perhitungan konstruksi pemikul utama juga dilakukan perhitungan konstuksi sekunder yang meliputi ikatan angin bawah, ikatan angin busur atas dan ikatan angin busur bawah. Dari hasil perencanaan didapat profil yang dipakai dalam perencanaan jembatan pelengkung type throught arch di Desa korek, Kec. Ambawang, Kab. Kubu Raya (KALBAR), yaitu: Gelegar Memanjang IWF 400 x 300 x 16 x 10, Gelegar Melintang IWF 700 nx 300 x 28 x 15, Ikatan Angin Bawah, Ikatan Angin Busur Atas dan Ikatan Angin Busur Bawah IWF 150 x 150 x 10 x 7, Busur Atas 30\u27\u27 WF 30 x 15, Busur Bawah 30\u27\u27 WF 30 x 15, Gelegar Induk Bagian Tepi 30\u27\u27 WF 30 x 15, Batang Penggantung IWF 200 x 200 x 12 x 8, Batang Tegak IWF 200 x 200 x 12 x 8, Batang Diagonal IWF 200 x 200 x 12 x 8, Batang Tegak Bagian Tepi 30\u27\u27 WF 30 x 15 dan Batang Diagonal 30\u27\u27 WF 30 x 15
TRESIS (Transport and Environmental Strategy Impact Simulator): Application to a Case Study in NE Sydney
This paper presents an integrated microsimulation urban passenger transport model system (TRESIS) for evaluating the impact of a large number of interrelated policy instruments on urban travel behavior and the environment. The model system has four integrated modules defining household location and automobile choices, commuter workplace and commuting travel choices, non-commuting travel activity, and worker distributed work practices. The demand model system, estimated as a set of discrete and continuous choice models, is combined with a set of equilibrating criteria in each of the location, automobile and commuting markets to predict overall demand for passenger travel in various socio-economic segments, automobile classes and geographic locations. The current version has been developed to operate at a high level of aggregation for the Sydney region, comprising a 14-zone system, with a spider-web network, and is designed to explore the impacts of broad strategic directions. The model system is embedded within a decision support system to make it an attractive suite of tools for practitioners. We illustrate the usefulness of TRESIS to a major investment option in Northeast Sydney, to replace a bottleneck opening bridge with either bridge improvements together with improvements to a number of intersections on the roads serving the region, or several possible tunnel options, including different levels of tolls for the tunnels. The application of TRESIS to this case was considered a success, with the model providing useful outputs on the revenue implications of various alternative tolls, the impacts of the proposals on regional travel, and the likely effects on public transport ridership
Genome sequence analysis of La Crosse virus and in vitro and in vivo phenotypes
<p>Abstract</p> <p>Background</p> <p>La Crosse virus (LACV), family <it>Bunyaviridae</it>, is a mosquito-borne virus recognized as a major cause of pediatric encephalitis in North America with 70–130 symptomatic cases each year. The virus was first identified as a human pathogen in 1960 after its isolation from a 4 year-old girl who suffered encephalitis and died in La Crosse, Wisconsin. The majority of LACV infections are mild and never reported, however, serologic studies estimate infection rates of 10–30/100,000 in endemic areas.</p> <p>Results</p> <p>In the present study, sequence analysis of the complete LACV genomes of low-passage LACV/human/1960, LACV/mosquito/1978, and LACV/human/1978 strains and of biologically cloned derivatives of each strain, indicates that circulating LACVs are genetically stable over time and geographic distance with 99.6–100%, 98.9–100%, 97.8–99.6%, and 99.2–99.7% amino acid identity for N, NsS, M polyprotein, and L proteins respectively. We identified 5 amino acid differences in the RNA polymerase and 4 nucleotide differences in the non-coding region of the L segment specific to the human virus isolates, which may result in altered disease outcomes.</p> <p>Conclusion</p> <p>All three wild type viruses had similar <it>in vitro </it>growth kinetics and phenotypes in mosquito C6/36 and Vero cells, and similar levels of neurovirulence and neuroinvasiveness in Swiss Webster mice. The biologically cloned derivative of LACV/human/1960 was significantly less neuroinvasive than its uncloned parent and differed in sequence at one amino acid position in the G<sub>N </sub>glycoprotein, identifying this residue as an attenuating mutation.</p
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