Allocation of Authority in Agricultural Production Contracts

The objective of this paper is to develop a model that explains the involvement of first level handlers in farm level decisions. In particular, the research attempts to explain observed differences among levels of farmer's autonomy in production contracts of different agricultural commodities. We show that the trade off that a contractor faces for holding the decision rights for controlling production inputs varies for different production environments. In particular, the contractor prefers controlling inputs in production of commodities that have relatively uniform production environments, whereas it is more efficient to delegate the control to the producer for commodities that have diverse production environments.Agribusiness,

Cross wedge rolling of a Ti6Al4V (ELI) alloy: the experimental studies and the finite element simulation of the deformation and failure

The cross wedge rolling (CWR) deformation and fracture of a Ti6Al4Al (ELI) alloy were investigated experimentally and numerically using a coupled thermomechanical finite element model analysis. The experimentally determined flow stress and damage model parameters were verified by tension split Hopkinson pressure bar testing of notched samples. The simulation and experimental CWR forces showed well agreements except near the end of the stretching zone. The model analysis showed that the temperature distribution in the work piece was nonuniform during the CWR. When the initial temperature of the work piece was relatively low, the work piece temperature increased, a heating effect of the plastic deformation, while relatively high initial work piece temperatures resulted in cooling the work piece, caused by the work piece contact with the tools. The cracks were shown numerically to initiate in the midsections of the work piece during the guiding action and elongated in a direction normal to the maximum tensile stress triaxiality, resulting in cruciformshaped crack formation, which was well agreed with the previously observed crack shape

Symmetry analysis and exact solutions of modified Brans-Dicke cosmological equations

We perform a symmetry analysis of modified Brans-Dicke cosmological equations and present exact solutions. We discuss how the solutions may help to build models of cosmology where, for the early universe, the expansion is linear and the equation of state just changes the expansion velocity but not the linearity. For the late universe the expansion is exponential and the effect of the equation of state on the rate of expansion is just to change the constant Hubble parameter.Comment: LaTeX2e source file, 14 pages, 7 reference

Suitability of foramen magnum measurements in sex determination and their clinical significance

Background: The foramen magnum provides a transition between fossa cranii posterior and canalis vertebralis. Medulla oblongata, arteria vertebralis and nervus accessorius spinal part pass through the foramen magnum. In this study, we aimed to make the morphometric measurements of the foramen magnum on computed tomography (CT) and to determine the feasibility of sex determination based on these measurements. Besides sex determination, from a clinical aspect, it is important to know the measurements of the foramen magnum in the normal population in terms of diseases characterised by displacement of the posterior fossa structures through foramen magnum to upper cervical spinal canal such as Chiari malformations and syringomyelia. Materials and methods: All the data for our study was obtained retrospectively from 100 patients (50 males, 50 females) who had a CT scan of the head and neck region in Adnan Menderes University Hospital, Department of Radiology. To examine the foramen magnum in each and every occipital bone, we measured the foramen magnum’s anteroposterior diameter, transverse diameter, the area of the foramen magnum and its circumference. Results: We found that men have a higher average value than women in our study. According to Student’s t-test results; in all measured parameters, there is significant difference between the genders (p < 0.05). When multivariate discriminant function test is performed for all four measurements, the discrimination rate is 64% for all women, 70% for all men and 67% for both genders. Conclusions: As a result of our study, the metric data we obtained will be useful in cases where the skeletons’ sex could not be determined by any other methods. We believe that, our study may be useful for other studies in determining of sex from foramen magnum. Our measurements could give some information of the normal ranges of the foramen magnum in normal population, so that this can contribute to the diagnosis process of some diseases by imaging. (Folia Morphol 2018; 77, 1: 99–104)  

Risk-based analytical modelling of managerial processes in shipping business

Gemi işletmeciliği faaliyetleri uluslararası platformda, yüksek rekabet koşulları altında ve her geçen gün yükselen öz-denetim olgusu gibi kısıtlar altında yürütülmektedir. Bu tür kısıtlar, gemi işletmeciliğinde profesyonel anlayışa geçişe ve yenilikçi yürütme faaliyetlerine sürekli gelişim hedefi ile yönelimi tetikler. Son yıllarda, sertifikalandırma kuruluşları ve denizcilik danışmanlık grupları gemi işletmeciliği idarecilerine Entegre Yönetim Sistemini (EYS) ileri bir çözüm aracı olarak önermektedir. Gemi işletmeciliğinde EYS uygulamalarının kapsamı uluslararası tanınmış standartların gemi güvenliği ve gemilerden kaynaklanan kirliliğin önlenmesi ile ilgili zorunlu denizcilik kurallarıyla birleştirilmesi esası üzerinedir. Bu noktada, standart gereksinimlerinin uyumluluğu ve ilgili kuralların gemi işletmeciliği yönetim organizasyonuna entegrasyonu iki temel sorun olarak ortaya çıkmaktadır. Bu araştırma ile Bulanık Bilgi Aksiyomu (BBA), Hata Ağacı Analizi (HAA), Analitik Ağ Süreci (AAS) ve diğer başlıca Çok Ölçütlü Karar Verme (ÇÖKV) yöntemlerini de içeren bir Risk Bütünleşik Karar Destek Sistemi (RBKDS) geliştirildi. RBKDS, Veri Tabanlı Yönetim Sistemi (VTYS), Model Esaslı Yönetim Sistemi (MEYS), BBA esaslı Model Seçim Arayüzü (BBA-MSA), Entegre Süreç Yönetim Modülü (ESYM), İdari Karar Verme Modülü (IKVM) ve Risk Kontrol Ve Yönetim Modülü (RKYM) gibi unsurların bütünleştirilmesi ile oluşmuştur. Tamamlanan prototip uygulama ile RBKDS’ın EYS’nin süreç temelli entegrasyonu ve gemi işletmeciliğinde yönetimsel süreçlerin risk temelli analitik çözümü konusunda gemi işletmeciliği idarecilerini destekleyen nitel çıktılar ortaya koyduğu görülmüştür. Süreç idaresi prosedürlerinin yeniden tasarımına karar desteğinin yanı sıra, RBKDS, ayrıca farklı standartlar arası uyumsuzluk risklerini de göz önünde bulundurarak yönetimsel süreçler üzerine etkin karar vermeyi sağlamaktadır.   Anahtar Kelimeler: Gemi işletmeciliği, karar destek sistemi, entegre yönetim sistemi.Relevance to legislation in shipping business cycle, the International Maritime Organization (IMO) principally governs the safety and environmental protection via Flag State Implementation (FSI) and regional Port State Control (PSC) authorities in accordance with the designated Memorandum Of Understandings (MOUs). Although the IMO has adopted various conventions, mainly concerning marine safety, security, pollution prevention, and other relevant issues, enforcement of the international commitments and standards in trading activities of ships necessitate the involvement of maritime stakeholders. The IMO declared that there are now enough regulations in place and the problem is one of implementation and enforcement. In accordance with the recent trends in international maritime legislation, the implementation process of regulatory regime has become a competitive factor for the market players to achieve the sustainable development target in maritime transportation industry. Industrial response to this trend recalls the self-regulation. It is appeared as relatively a new regime for shipping business initiatives in maritime transportation industry. Extensively, the self-regulation dominates the industry and it mainly enforces the maritime stakeholders involvement in enhancement of the safety/environmental aspects for shipping business. Beside safety and environmental contributions, the self-regulation spontaneously ensures legislative performance of the relevant organizations such as classification societies, insurers, cargo owners, shippers, shipbrokers, ship managers, terminal operators and, ship financiers in trading activities satisfactorily. Implementation of an Integrated Management System (IMS) is one of the most effective and concrete instruments of managing the self-regulation phenomenon in order to respond to increasing demands from maritime society. In principle, the concept of IMS practices in shipping business is based on combining internationally recognized voluntary standards with the mandatory maritime 8regulations that are mainly concern with ship safety and the prevention of pollution from ships. In the early design phase of an IMS, cooperative efforts of maritime consultancies and relevant shipping executives targets to enable maximum improvement in managerial processes while reducing the costs and excessive bureaucracy in implementation of redesigned procedures. As potential clients, the third party groups such as cargo owners and contracted charterers have closely monitored the performance effects of IMS integration into professional shipping companies. Therefore, the managerial efforts are extremely valuable for the purpose of benefit from IMS implementations, which increase the reputation of ship management companies and provide an enormous trading advantage in maritime transportation industry. This research develops a Risk Integrated Decision Support System (RIDSS) based on a multi-methodological background includes Fuzzy Axiomatic Design (FAD) and Fault Tree Analysis (FTA), as well as Analytic Network Process (ANP) and other principal MCDM methods. The initial focus of the RIDSS is to reveal quantitative outcomes in order to encourage relevant shipping executives towards process-based integration of an IMS also to enhance risk-based analytical modelling of managerial processes in shipping business. The RIDSS consists of various modules such as Database Management System (DBMS), Model Base Management System (MBMS), FAD-based Model Selection Interface (FAD-MSI), Integrated Process Management Module (IPMM), Executive Decision-Making Module (EDMM), and Risk Control And Management Module (RCMM) with a high level of integrity. To demonstrate the proposed RIDSS, the mostly encountered managerial processes in commercial, technical, and operational levels of shipping business are then addressed and modelled. Specifically, the prototype application of the RIDSS incorporates the following process:(i) shipboard personnel recruitment, (ii) familiarization and training, (iii) performance appraisals of marine suppliers, (iv) marine equipment/spare purchasing, (v) fleet maintenance planning, (vi) accident analysis and prevention, (vii) Ship docking operations management, (viii) performance measurement for emergency drills. Besides decision aid to redesigning of process execution procedures through IMS requirements, the RIDSS also enables an effective decision-making on managerial processes even considering the potential risks of regulatory incompliance.  Keywords: Shipping business, decision support system, integrated management system.

Dynamic connectivity algorithms for Monte Carlo simulations of the random-cluster model

We review Sweeny's algorithm for Monte Carlo simulations of the random cluster model. Straightforward implementations suffer from the problem of computational critical slowing down, where the computational effort per edge operation scales with a power of the system size. By using a tailored dynamic connectivity algorithm we are able to perform all operations with a poly-logarithmic computational effort. This approach is shown to be efficient in keeping online connectivity information and is of use for a number of applications also beyond cluster-update simulations, for instance in monitoring droplet shape transitions. As the handling of the relevant data structures is non-trivial, we provide a Python module with a full implementation for future reference.Comment: Contribution to the "XXV IUPAP Conference on Computational Physics" proceedings; Corrected equation 3 and error in the maximal number of edge level

Fatal bilateral pneumonitis after locoregional thoracic chemoradiation in a transplanted patient under immunosuppressive therapy

Background: After thoracic radiotherapy a pneumonitis may occur, mostly confined to the irradiated volume of the lung. In general, it resolves spontaneously without long-term effects. Case Report: A 68-year-old man was diagnosed with a stage IIIA adenocarcinoma of the lung and was treated with sequential chemoradiation. He had a heart and kidney transplant for which an immunosuppressant was taken. During the fourth week of radiotherapy, he developed a bilateral interstitial pneumonia. Despite antibiotics and steroids, the patient died twelve days after the onset of complaints due to respiratory failure. Autopsy showed in all pulmonary lobes extensive diffuse alveolar damage, probably leading to respiratory insufficiency and death. Literature and Conclusion: Bilateral pneumonitis after radiotherapy is thought to be an immunologically-mediated response, which usually resolves without long-term effects. Since in radiation pneumonitis an increase in T-cells is described, the suppression of these cells by an immunosuppressant might have exaggerated the pulmonary toxicity

Killing Vector Fields in Three Dimensions: A Method to Solve Massive Gravity Field Equations

Killing vector fields in three dimensions play important role in the construction of the related spacetime geometry. In this work we show that when a three dimensional geometry admits a Killing vector field then the Ricci tensor of the geometry is determined in terms of the Killing vector field and its scalars. In this way we can generate all products and covariant derivatives at any order of the ricci tensor. Using this property we give ways of solving the field equations of Topologically Massive Gravity (TMG) and New Massive Gravity (NMG) introduced recently. In particular when the scalars of the Killing vector field (timelike, spacelike and null cases) are constants then all three dimensional symmetric tensors of the geometry, the ricci and einstein tensors, their covariant derivatives at all orders, their products of all orders are completely determined by the Killing vector field and the metric. Hence the corresponding three dimensional metrics are strong candidates of solving all higher derivative gravitational field equations in three dimensions.Comment: 25 pages, some changes made and some references added, to be published in Classical and Quantum Gravit