Consistency Problems for Jump-Diffusion Models

In this paper consistency problems for multi-factor jump-diffusion models, where the jump parts follow multivariate point processes are examined. First the gap between jump-diffusion models and generalized Heath-Jarrow-Morton (HJM) models is bridged. By applying the drift condition for a generalized arbitrage-free HJM model, the consistency condition for jump-diffusion models is derived. Then we consider a case in which the forward rate curve has a separable structure, and obtain a specific version of the general consistency condition. In particular, a necessary and sufficient condition for a jump-diffusion model to be affine is provided. Finally the Nelson-Siegel type of forward curve structures is discussed. It is demonstrated that under regularity condition, there exists no jump-diffusion model consistent with the Nelson-Siegel curves.Comment: To appear in Applied Mathematical Financ

Free-space quantum links under diverse weather conditions

Free-space optical communication links are promising channels for establishing secure quantum communication. Here we study the transmission of nonclassical light through a turbulent atmospheric link under diverse weather conditions, including rain or haze. To include these effects, the theory of light transmission through atmospheric links in the elliptic-beam approximation presented by Vasylyev et al. [D. Vasylyev et al., Phys. Rev. Lett. 117, 090501 (2016); arXiv:1604.01373] is further generalized.It is demonstrated, with good agreement between theory and experiment, that low-intensity rain merely contributes additional deterministic losses, whereas haze also introduces additional beam deformations of the transmitted light. Based on these results, we study theoretically the transmission of quadrature squeezing and Gaussian entanglement under these weather conditions.Comment: 14 pages, 8 figure

Progress in Haploidentical Hematopoietic Stem Cell Transplantation

Haploidentical hematopoietic cell transplantation (HaploHCT), with cells from HLA-half-matched first degree related donors (siblings, children and parents), could revolutionize hematopoietic transplantation as it expands this form of treatment to approximately 40% of patients who do not have an HLA-matched donor in USA. This need is particularly acute in developing countries, which usually do not have an unrelated donor registry and/or cost is a major issue in acquiring unrelated donor stem cells. Accordingly, the number of haploSCTs done in USA, Europe, China, and developing countries is on the rise. Advantages to HaploHCT include almost universal (more than 95% of patients will have a half-matched related donor) and immediate availability of donor progenitor cells, the opportunity to select the best donor among family members to minimize treatment-related mortality, decrease relapse rate and improve outcomes [2], and the possibility to collect donor cells for cellular therapy post-transplantation, with the goal to enhance the anti-tumor effects of the graft. Despite its potential advantages, until recently, high donor-recipient HLA-histoincompatibility has proven very difficult to overcome

Extraction of Saponins from Soapnut (Sapindus Mukorossi) and Their Antimicrobial Properties

In this study optimization of extraction conditions for saponin from Sapindus mukorossi was investigated. Results showed that polarity of the extraction solvent affects the yield percentage of the extraction process. Best yield percentage was obtained as 78.1 % at 1:10 solid-liquid ratio in aqueous ethanol solution (50% v/v). The antimicrobial properties of extracts containing saponins were investigated for different microorganisms. Minimum inhibition concentrations of extract were obtained against Escherichia coli, Staphylococcus aureus and Candida albicans. Minimum inhibition concentrations (MIC) of saponin extract ranged between 12.5 mg/mL to 25 mg/mL.nbs

Design of Hydroxyapatite/Magnetite (HAP/Fe3O4) Based Composites Reinforced with ZnO and MgO for Biomedical Applications

Hydroxyapatite (HAP-- Ca 10(PO4 )6 (OH)2 ) is a biocompatible and bioactive material that is widely used for biomedical applications, especially in bone replacements. It has good load carrying capacity; however, it lacks antibacterial property. New bio-composites based on bovine hydroxyapatite doped with, magnetite iron oxide (HAP/ Fe3 O4 ) matrix reinforced with ZnO and MgO nanoparticles are proposed for biomedical applications that provide improved antibacterial activity with potential to be used in magnetic therapy. Microwave sintering was used to manufacture the composites. The microstructure evolution in these composites were studied by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Density, microhardness, compressive strength of the composites was measured and compared along with their magnetic properties. Finite element analysis simulations were performed for the compression tests

Service value creation in supplier-buyer interactions

Tedarik Zinciri Yönetimi (TZY), imalat, yöneylem, müşteri yönetimi ve dağıtım gibi değişik disiplinlerin ilgisini çekmiştir. Küresel tedarik, zaman ve kalite temelli rekabet, teknolojik gelişmeler ve çevresel belirsizlik unsurları sonucunda, TZY akademik araştırmalar için güncel bir başlık haline gelmiştir. Artan küresel rekabet, tedarik zinciri halkalarının birbirleri ile daha yakın koordinasyon sağlamasını ve kendilerini diğer halkaların konumlarını dikkate alarak daha iyi hizalamalarını gerektirmektedir. Bu sebeple, tedarikçi-alıcı çiftlerinin yakından incelenmesi hayati önem taşımaktadır. Fiyat bir ürünün en önemli özelliği haline dönüştükçe karlılık düşmekte, rekabet avantajı azalmaktadır, buna ek olarak  bilişim teknolojilerinin tedarikçi-alıcı çiftlerinin daha yakın koordinasyonuna imkan tanımayan araçları geliştikçe, tedarikçiler ürünlerini sundukları hizmetler ile desteklemektedirler. Öyle ki, hizmet kalitesi, ürün kalitesinden daha önemli bir sipariş kazandıran olarak anılmaktadır. Ancak, hizmetler yolu ile farklılaştırma yakalanması zor bir kavramdır. Ürünlere eşlik ederek melez ürün oluşumuna katkıda bulunan hizmetler, tedarikçilerin rekabetçiliklerini daha da geliştirebilecekleri unsurlar arasında yer almaktadır. Ancak, alıcıların hizmetlere dair öznel beklentilerinin gelişimleri ve değişkenlikleri sebebi ile tedarikçiler sunumunda bulunacakları hizmet seviyesi gereklerini öngörmekte zorlanmaktadırlar. Bu çalışmanın hedeflediği amaçlar çeşitlidir. Hizmetlerin Tedarik Zinciri Yönetimi (TZY) içerisindeki önemini ortaya koyarak, tedarikçi-alıcı etkileşimlerinde katma değer yaratabilme kabiliyetlerini ortaya koymak bu amaçlardan ilkidir. Ayrıca, tedarikçilerin alıcılarının hizmet seviyesi gereklerini belirleyebilmeleri için Snell Kanunu’ndan yararlanılarak, tedarikçilere ışık tutacak bir model geliştirmek de amaçlanmaktadır. Anahtar Kelimeler: Tedarik Zinciri Yönetimi, Tedarikçi-Alıcı etkileşimi, hizmetler, değer yaratımı.Supply chain management has attracted attention from various multi-disciplinary fields, which include manufacturing, operations management, customer management and transportation. Global sourcing, time and quality based competition, improvements in technology, and environmental uncertainties have placed supply chain management as a timely topic for academic research. Defect-free, fast and reliable delivery has almost become the necessities to be in the market, rather than competitive advantage. Ever stiff competition in the global arena calls for closer coordination and better alignment between supply chain participants. Therefore, a closer examination of supplier and buyer interactions is vital. As price becomes the most important feature of a product and reduces profitability and competitive advantage, and as information technology tools that help in a closer coordination with buyer and supplier emerge, suppliers get engaged in providing services around their products. Moreover, service quality is referred as a more important order winner than the product quality. Yet differentiation via services dimension is not an easy concept to grasp. Firms often perform services according to the norms they have established over years of experience. Though, the breadth of experience commonly varies from one firm to another. Therefore, norms adopted for services vary, too. A norm considered for a specific service in one company might not exist at another company, or even if exist could be underestimated. When placed in the context of complex supply chains, this presents a supplier with often buyers that have different services' norms. A certain aspect of a supplier's service might be deemed superior at one buyer, while normal or even inferior at another buyer. Therefore, provision of services in supply chain management presents a promising research area. There is a need to understand if supplier's provision of services is capable of generating superior or inferior perceived buyer value. For a firm to gain and retain value additive beneficial relationships with its buyers, its offer should often involve some social values (something that will make buyer's life a better one) either by clearly identifying the needs of its buyers or by outperforming what other suppliers already do. Suppliers demand more information on sophisticated norms and specifications of their buyers to formulate their services. This research attempts to shed the light on the issues discussed, and also uncover the possible causes of superior perceived buyer value creation upon supplier's provision of services in supply chain. An exploratory research model has been developed by the aid of an analogy from Snell's Law of the physics as services creation of value has an instantaneous nature like that of the passage of a beam of light from one medium to another one. Two propositions had stemmed from the exploratory research. Firstly, lower operational medium on supply side is likely to cause inferiority in perceived buyer value for an encounter. Secondly, higher operational medium on supply side is likely to cause superiority in perceived buyer value for an encounter. A panel of experts had been devised to confirm usefulness and meaningfulness of the developed model. The research process for the panel of experts was a qualitative technique based on an interpretive orientation. Participants included 9 provincial individuals. In all, there were 19 interviews, involving 9 individuals. In four instances more than one person participated in an interview. Thirteen of the interviews were face-to-face, and three were conducted by telephone. Interviewees confirmed the model by the practices they are involved within the industry, as well as with the exemplifying issues they have presented. No changes were requested for the developed exploratory model. The main contribution of this research endeavor to academia is the developed exploratory model, which explains creation of superior perceived buyer value via provision of services in a supplier-buyer interaction. Therefore, reference disciplines, including supply chain management and services have received contribution. High levels of services are often costly for suppliers to adopt for the entire buyer base due to two major reasons: the unnecessary high costs incurred for buyers who were not necessarily expecting such high services for value creation, and the dramatically raised expectations which will set the base for all forthcoming services of the supplier that'll force the supplier to perform an ever higher levels of services. Developed model facilitates detection of possible opportunities to improve service levels through which a supplier can create superior perceived buyer value. Keywords: Supply chain management, supplier-buyer interaction, services, value creation

Service value creation in supplier-buyer interactions

Tedarik Zinciri Yönetimi (TZY), imalat, yöneylem, müşteri yönetimi ve dağıtım gibi değişik disiplinlerin ilgisini çekmiştir. Küresel tedarik, zaman ve kalite temelli rekabet, teknolojik gelişmeler ve çevresel belirsizlik unsurları sonucunda, TZY akademik araştırmalar için güncel bir başlık haline gelmiştir. Artan küresel rekabet, tedarik zinciri halkalarının birbirleri ile daha yakın koordinasyon sağlamasını ve kendilerini diğer halkaların konumlarını dikkate alarak daha iyi hizalamalarını gerektirmektedir.  Bu sebeple, tedarikçi-alıcı çiftlerinin yakından incelenmesi hayati önem taşımaktadır. Fiyat bir ürünün en önemli özelliği haline dönüştükçe karlılık düşmekte, rekabet avantajı azalmaktadır, buna ek olarak  bilişim teknolojilerinin tedarikçi-alıcı çiftlerinin daha yakın koordinasyonuna imkan tanımayan araçları geliştikçe, tedarikçiler ürünlerini sundukları hizmetler ile desteklemektedirler. Öyle ki, hizmet kalitesi, ürün kalitesinden daha önemli bir sipariş kazandıran olarak anılmaktadır. Ancak, hizmetler yolu ile farklılaştırma yakalanması zor bir kavramdır. Ürünlere eşlik ederek melez ürün oluşumuna katkıda bulunan hizmetler, tedarikçilerin rekabetçiliklerini daha da geliştirebilecekleri unsurlar arasında yer almaktadır. Ancak, alıcıların hizmetlere dair öznel beklentilerinin gelişimleri ve değişkenlikleri sebebi ile tedarikçiler sunumunda bulunacakları hizmet seviyesi gereklerini öngörmekte zorlanmaktadırlar. Bu çalışmanın hedeflediği amaçlar çeşitlidir. Hizmetlerin Tedarik Zinciri Yönetimi (TZY) içerisindeki önemini ortaya koyarak, tedarikçi-alıcı etkileşimlerinde katma değer yaratabilme kabiliyetlerini ortaya koymak bu amaçlardan ilkidir. Ayrıca, tedarikçilerin alıcılarının hizmet seviyesi gereklerini belirleyebilmeleri için Snell Kanunu’ndan yararlanılarak, tedarikçilere ışık tutacak bir model geliştirmek de amaçlanmaktadır. Anahtar Kelimeler: Tedarik zinciri yönetimi, tedarikçi-alıcı etkileşimi, hizmetler, değer yaratımı.Supply chain management has attracted attention from various multi-disciplinary fields, which include manufacturing, operations management, customer management and transportation. Global sourcing, time and quality based competition, improvements in technology, and environmental uncertainties have placed supply chain management as a timely topic for academic research. Defect-free, fast and reliable delivery has almost become the necessities to be in the market, rather than competitive advantage. Ever stiff competition in the global arena calls for closer coordination and better alignment between supply chain participants. Therefore, a closer examination of supplier and buyer interactions is vital. As price becomes the most important feature of a product and reduces profitability and competitive advantage, and as information technology tools that help in a closer coordination with buyer and supplier emerge, suppliers get engaged in providing services around their products. Moreover, service quality is referred as a more important order winner than the product quality. Yet differentiation via services dimension is not an easy concept to grasp. Firms often perform services according to the norms they have established over years of experience. Though, the breadth of experience commonly varies from one firm to another. Therefore, norms adopted for services vary, too. A norm considered for a specific service in one company might not exist at another company, or even if exist could be underestimated. When placed in the context of complex supply chains, this presents a supplier with often buyers that have different services' norms. A certain aspect of a supplier's service might be deemed superior at one buyer, while normal or even inferior at another buyer. Therefore, provision of services in supply chain management presents a promising research area. There is a need to understand if supplier's provision of services is capable of generating superior or inferior perceived buyer value. For a firm to gain and retain value additive beneficial relationships with its buyers, its offer should often involve some social values (something that will make buyer's life a better one) either by clearly identifying the needs of its buyers or by outperforming what other suppliers already do. Suppliers demand more information on sophisticated norms and specifications of their buyers to formulate their services. This research attempts to shed the light on the issues discussed, and also uncover the possible causes of superior perceived buyer value creation upon supplier's provision of services in supply chain. An exploratory research model has been developed by the aid of an analogy from Snell's Law of the physics as services creation of value has an instantaneous nature like that of the passage of a beam of light from one medium to another one. Two propositions had stemmed from the exploratory research. Firstly, lower operational medium on supply side is likely to cause inferiority in perceived buyer value for an encounter. Secondly, higher operational medium on supply side is likely to cause superiority in perceived buyer value for an encounter. A panel of experts had been devised to confirm usefulness and meaningfulness of the developed model. The research process for the panel of experts was a qualitative technique based on an interpretive orientation. Participants included 9 provincial individuals. In all, there were 19 interviews, involving 9 individuals. In four instances more than one person participated in an interview. Thirteen of the interviews were face-to-face, and three were conducted by telephone. Interviewees confirmed the model by the practices they are involved within the industry, as well as with the exemplifying issues they have presented. No changes were requested for the developed exploratory model. The main contribution of this research endeavor to academia is the developed exploratory model, which explains creation of superior perceived buyer value via provision of services in a supplier-buyer interaction. Therefore, reference disciplines, including supply chain management and services have received contribution. High levels of services are often costly for suppliers to adopt for the entire buyer base due to two major reasons: the unnecessary high costs incurred for buyers who were not necessarily expecting such high services for value creation, and the dramatically raised expectations which will set the base for all forthcoming services of the supplier that'll force the supplier to perform an ever higher levels of services. Developed model facilitates detection of possible opportunities to improve service levels through which a supplier can create superior perceived buyer value. Keywords: Supply chain management, supplier-buyer interaction, services, value creation

A review of timetabling and resource allocation models for light-rail transportation systems

This paper surveys the relevant operations research literature on timetabling and resource allocationproblems with a special attention paid to the transportation systems. The purpose of this review is to define the critical objectives, determine the key components and identify the key issues for developing a comprehensive mathematical model for timetabling of light rail transit vehicles in sequence with the assignment of drivers as an available resource. In doing so, the implications of the emerging timetabling research is discussed, components of the mathematical models proposed are reviewed, and the extend they reflect real business practices are analyzed. Finally, fundamental issues and primary elements of a simple model in association with general timetabling and resource allocation problems are presented

Exploring wind direction and SO2 concentration by circular-linear density estimation

The study of environmental problems usually requires the description of variables with different nature and the assessment of relations between them. In this work, an algorithm for flexible estimation of the joint density for a circular-linear variable is proposed. The method is applied for exploring the relation between wind direction and SO2 concentration in a monitoring station close to a power plant located in Galicia (NW-Spain), in order to compare the effectiveness of precautionary measures for pollutants reduction in two different years.Comment: 17 pages, 7 figures, 2 table

Electrically Small Supergain Arrays

The theory, computer simulations, and experimental measurements are presented for electrically small two-element supergain arrays with near optimal endfire gains of 7 dB. We show how the difficulties of narrow tolerances, large mismatches, low radiation efficiencies, and reduced scattering of electrically small parasitic elements are overcome by using electrically small resonant antennas as the elements in both separately driven and singly driven (parasitic) two-element electrically small supergain endfire arrays. Although rapidly increasing narrow tolerances prevent the practical realization of the maximum theoretically possible endfire gain of electrically small arrays with many elements, the theory and preliminary numerical simulations indicate that near maximum supergains are also achievable in practice for electrically small arrays with three (and possibly more) resonant elements if the decreasing bandwidth with increasing number of elements can be tolerated.Comment: 10 pages, 11 figures, submitted to IEEE Transactions on Antennas and Propagation (December 2006