HEDGING WHOLESALE BEEF CUTS

Live cattle futures markets do not offer much opportunity for effective hedging of wholesale beef cuts. If a Choice-to-Select price spread futures contract were introduced this would enhance hedging effectiveness although likely not enough to encourage cross hedging. If a Choice boxed beef futures contract were introduced, hedging Choice wholesale beef cuts would be less risky and the addition of a Choice-to-Select price spread would enhance hedging effectiveness especially for Select wholesale beef cuts.Livestock Production/Industries, Marketing,

Mechanical behavior and stability control of regenerated roof in long wall stratified mining of thick steeply dipping coal seam

This study focused on the stability control of roof in long wall stratified mining of large dip angle thick coal seam. Taking Panbei Coal Mine in Huainan as an example, the effect mechanism of water content, compression ratio and grain size grading on the compression characteristics of gangue is analyzed by comprehensive application of gangue lateral compression test, 3D imaging borehole detection test, physical simulation and numerical simulation method. In addition, the effect of these factors on the stability of the reclaimed roof were also analyzed, the structural characteristics and stress state of the reclaimed roof were obtained, the dynamic behavior of the reclaimed roof was revealed, the stability control measures of the reclaimed roof were formulated, and the control effect of the reclaimed roof stability was evaluated. The research results indicate that the clay minerals of goaf mudstone and sandy mudstone are beneficial for the secondary cementation of gangue. The contact state and stress state of the gangue during compression under load are constantly adjusted, manifested as the compression and bonding degree of the lower and upper gangue being higher than that of the middle, with the compression and bonding degree of the middle and upper gangue being the smallest, and the regenerated roof being more prone to damage. The particle size distribution of gangue is the main factor affecting the shear strength of recycled roof. As the particle size of the gangue increases, the regenerated roof exhibits ductile failure that slides along the shear line to the staggered and bulging of the gangue particles. That is, the degree of mining fracture in the lower part of the regenerated roof tends to be milder than in the middle and upper parts, and the middle and upper parts are the key prevention and control areas for the stability control of the regenerated roof. The deflection of the main stress can lead to the fracture of the regenerated roof, so a plan for the collapse of the regenerated roof and the grouting

The Genus Adonis as an Important Cardiac Folk Medicine: A Review of the Ethnobotany, Phytochemistry and Pharmacology

The genus Adonis L. (Ranunculaceae), native to Europe and Asia, comprises 32 annual or perennial herbaceous species. Due to their cardiac-enhancing effects, Adonis spp. have long been used in European and Chinese folk medicine. These plants have been widely investigated since the late 19th century, when the cardiovascular activity of Adonis vernalis L. was noted in Europe. The present paper provides a review of the phytochemistry, biological activities and toxicology in order to highlight the future prospects of the genus. More than 120 chemical compounds have been isolated, with the most important components being cardiac glycosides as well as flavones, carotenoids, coumarins and other structural types. Plants of the genus, especially A. vernalis L. and A. amurensis Regel & Radde, their extracts and their active constituents possess broad pharmacological properties, including cardiovascular, antiangiogenic, antibacterial, antioxidant, anti-inflammatory and acaricidal activities, and exhibit both diuretic effects and effects on the central nervous system. However, most plants within the 32 species have not been comprehensively studied, and further clinical evaluation of their cardiovascular activity and toxicity should be conducted after addressing the problem of the rapidly decreasing resources. This review provides new insight into the genus and lays a solid foundation for further development of Adonis

Abstract IMPROVING PORTFOLIO EFFICIENCY: A GENETIC ALGORITHM APPROACH

In this paper, I present a decision-making process that incorporates a Genetic Algorithm (GA) into a state dependent dynamic portfolio optimization system. A GA is a probabilistic search approach and thus can serve as a stochastic problem solving technique. A Genetic Algorithm solves the model by forward-looking and backward-induction, which incorporates both historical information and future uncertainty when estimating the asset returns. It significantly improves the accuracy of expected return estimation and thus improves the overall portfolio efficiency over the classical mean-variance method. In addition a GA could handle a large variety of future uncertainties, which overcome the computational difficulties in the traditional Bayesian approach

Essays in financial propagation and corporate inventory investment behavior

The three chapters comprising this Ph.D. dissertation focus on how financial propagation affects firms’ inventory investment dynamics. These studies will enrich the current literature on inventory behavior and macroeconomic activities. In the first chapter, I investigate the role of financ ial frictions on corporate inventory investment dynamics. The prevailing production smoothing inventory theory can not explain the empirical findings—why production is more volatile than sales and why inventories and sales are positively correlated? I deve lop a tractable linearized version of equation based on a firm’s optimization problem which describes the joint evolution of inventory investment and financial variables. The empirical results support the significance of financial frictions for firms’ inventory investment behavior. In the second chapter, I incorporate both trade credit and bank loans into the traditional production smoothing inventory model. The main purposes of this study are to first investigate the impact of trade credit for firm’s inventory investment dynamics in imperfect capital markets, and second to test whether the use of trade credit is a substitution or a complement for bank loans. I find that the use of trade credit can significantly mitigates financial stress and helps firms overcome liquidity shortages. This finding illustrates a channel to dampen the impact of contractionary monetary policy and make the consequent reduction of the inventory investment less severe. Moreover, this study provides evidence showing that trade credit and bank loans are not perfect substitutes. These findings have important implications for both monetary policy and corporate financing management. In the last chapter, I present a decision-making process that incorporates a Genetic Algorithm (GA) into a state dependent dynamic portfolio optimization system. A GA solves the model by forward-looking and backward-induction, which incorporates both historical information and future uncertainty when estimating the asset returns. It significantly improves the accuracy of expected return estimation and thus improves the overall portfolio efficiency over the classical mean-variance method.Economic

HEDGING WHOLESALE BEEF CUTS

Live cattle futures markets do not offer much opportunity for effective hedging of wholesale beef cuts. If a Choice-to-Select price spread futures contract were introduced this would enhance hedging effectiveness although likely not enough to encourage cross hedging. If a Choice boxed beef futures contract were introduced, hedging Choice wholesale beef cuts would be less risky and the addition of a Choice-to-Select price spread would enhance hedging effectiveness especially for Select wholesale beef cuts

Investigation of Energy and Damage Evolutions in Rock Specimens with Large-Scale Inclined Prefabricated Cracks by Uniaxial Compression Test and AE Monitoring

To explore the energy dissipation mechanism and damage evolution characteristics of rock specimens under compressive loading, we performed the acoustic emission (AE) testing under uniaxial compression in intact rock specimens and those with large-scale prefabricated cracks. The basic mechanical properties of both types of specimens were analyzed comprehensively, and the evolution patterns of strain energy indicators (total strain, elastic, and dissipative energies) in rock specimens before the peak on the stress-strain curve were identified. We further revealed the effect of the prefabricated crack dip angle, which controlled the surplus energy conversion of the following peak deformation and failure in the rock specimens. Using the modified equation of rock specimen damage evolution characterized by the AE energy and examining the fracture surface morphology via the scanning electron microscopy (SEM), the AE distribution law for rock specimen damage was revealed. An increase in the prefabricated crack dip angle was shown to reduce the peak stress and strain of rock specimens, which experienced a transition from the tensile and splitting failure mode to shear and slip one. Cracked rock specimens exhibited strain energy accumulation at the elastic deformation stage of the stress-strain diagram and rapid energy consumption at the plastic stage. By contrast, the intact rock specimens had a smoother energy evolution pattern. As the prefabricated crack dip angle increased, the dissipated and surplus strain energies’ shares increased. Moreover, the first peak of the AE energy occurred earlier, and the stress needed for its occurrence decreased as the dip angle increased. According to the damage evolution equation for rock specimens, their damage process can be subdivided into the initial damage, stable damage increase, and the accelerating damage increase stages. An increase in the prefabricated crack dip angle accelerated the damage accumulation in rock specimens. The locking effect of the sawtooth-like structures on the fracture surface was less conspicuous, and the fracture surface roughness increased. Thus, microcracks gradually developed, and rock specimens became more susceptible to sudden unstable failure

Rupture and Migration Law of Disturbed Overburden during Slicing Mining of Steeply Dipping Thick Coal Seam

Steeply inclined and thick coal seams in Huainan Panbei Coal Mine in Anhui Province, China, were analyzed by physical analog modeling, acoustic emission (AE), and distributed fiber sensing (DBS). The secondary deformation breakage law, sound, and light response characteristics in the rock mass deformation process induced by lower slice mining of steeply inclined coal seams were determined. The results show that the mutation of the hinged rock beam structure in the lower region and the cantilever beam structure in the upper region of the lower slice disturbed overburden is the main cause of the rupture of the workface roof. Based on the AE energy and distributed fiber strain response characteristics, the six stages of disturbed overburden instability in the lower slice and cyclic patterns of steeply inclined coal seams were revealed. The key prevention and control areas of the workface were found to be related to the disturbed high-level immediate roof rupture during the lower slice mining process, rupture of the disturbed main roof, and sliding of disturbed overburden. The three-stage AE positioning morphological characteristics and DBS response stepped jump patterns were analyzed in detail. The research results are considered instrumental in the combined AE and DBS monitoring of deformation and damage of rock and soil structures

Mining-Induced Stress-Fissure Field Evolution and the Disaster-Causing Mechanism in the High Gas Working Face of the Deep Hard Strata

The compound dynamic disaster of coal and gas outbursts and rockburst is a typical hazard jeopardizing the mining of the high gas content coal seam under a hard roof condition. In this study, the hard roof’s mechanism inducing this hazard is analyzed. Physical analog modeling experiments and in situ monitoring of mining-induced stress were performed during coal seam mining under a hard roof condition. The pattern of hard roof breakage effect on the stress-fissure field evolution was revealed. The elastic energy was released and propagated on both sides immediately after the hard roof breaking, leading to energy accumulation. Meanwhile, expansive roof collapse resulted in the intense weighting of the working face and rockburst. Thus, the coal and gas outburst occurred under the joint action of the impact energy generated by breaking the hard roof and gas expansion energy. In other words, the compound dynamic disaster happened. Synergistic stereoextraction integrating cross-seam drilling and along-seam drilling was combined with deep hole advanced presplitting blasting technology to cope with the compound dynamic disaster in the high gas coal seam under a hard roof condition