68,195 research outputs found
Efficiency tests of agricultural commodity futures markets in China
The efficiency of the Chinese wheat and soybean futures markets is studied. Formal statistical tests were conducted based on Johansen’s cointegration approach for three different cashmarkets and six different futures forecasting horizons ranging from1 week to 4 months.The results suggest a long-termequilibrium relationship between the futures price and cash price for soybeans and weak short-term efficiency in the soybean futures market. The futures market for wheat is inefficient, which may be caused by overspeculation and government intervention.cointegration, futures market, price, soybean, wheat, Marketing, Risk and Uncertainty,
Influence of nonlocal damping on the field-driven domain wall motion
We derive the complete expression of nonlocal damping in noncollinear
magnetization due to the nonuniform spin current pumped by precessional
magnetization and incorporate it into a generalized Thiele equation to study
its effects on the dynamics of the transverse and vortex domain walls (DWs) in
ferromagnetic nanowires. We demonstrate that the transverse component of
nonlocal damping slows down the field-driven DW propagation and increases the
Walker breakdown field whereas it is neglected in many previous works in
literature. The experimentally measured DW mobility variation with the damping
tuned by doping with heavy rare-earth elements that had discrepancy from
micromagnetic simulation are now well understood with the nonlocal damping. Our
results suggest that the nonlocal damping should be properly included as a
prerequisite for quantitative studies of current-induced torques in
noncollinear magnetization.Comment: 9 pages, 4 figure
IS CHINA'S AGRICULTURAL FUTURES MARKET EFFICIENT?
In this paper, we study the efficiency of the Chinese wheat and soybeans futures markets and assess the conditions in agricultural commodity futures and cash markets in China. Formal statistical tests are conducted through Johansen's cointegration approach to identify the long-term equilibrium relationship between futures and cash markets. Three different cash prices from Zhengzhou Grain Wholesale Market, Tianjin Grain Wholesale Market, and the national average wholesale price are used. The wheat futures price from China Zhengzhou Commodity Exchange and soybeans futures price from Dalian Commodity Exchange with different forecasting horizons ranging from one week to six months are also used. Results suggest that a long-term equilibrium relationship between the futures price and cash price for soybeans has been established. A weak short-term efficiency of the soybean futures market is revealed. The futures market for wheat is inefficient. The relative inefficient wheat market may be caused by over-speculation and government intervention, because wheat is the staple food in China and the government has more control over it than soybeans. Another reason is geographic proximities between the cash market in Tianjin and both the soybean production area and the futures market in Dalian.Marketing,
Analytical characterisation of the terahertz in-vivo nano-network in the presence of interference based on TS-OOK communication scheme
The envisioned dense nano-network inside the human body at terahertz (THz) frequency suffers a communication performance degradation among nano-devices. The reason for this performance limitation is not only the path loss and molecular absorption noise, but also the presence of multi-user interference and the interference caused by utilising any communication scheme, such as time spread ON—OFF keying (TS-OOK). In this paper, an interference model utilising TS-OOK as a communication scheme of the THz communication channel inside the human body has been developed and the probability distribution of signal-to-interference-plus-noise ratio (SINR) for THz communication within different human tissues, such as blood, skin, and fat, has been analyzed and presented. In addition, this paper evaluates the performance degradation by investigating the mean values of SINR under different node densities in the area and the probabilities of transmitting pulses. It results in the conclusion that the interference restrains the achievable communication distance to approximate 1 mm, and more specific range depends on the particular transmission circumstance. Results presented in this paper also show that by controlling the pulse transmission probability and node density, the system performance can be ameliorated. In particular, SINR of in vivo THz communication between the deterministic targeted transmitter and the receiver with random interfering nodes in the medium improves about 10 dB, when the node density decreases one order. The SINR increases approximate 5 and 2 dB, when the pulse transmitting probability drops from 0.5 to 0.1 and 0.9 to 0.5
A practical approach to managing patients with HCV infection.
Hepatitis C virus (HCV) infection is a major worldwide public health concern. It is a common cause of chronic liver disease and hepatocellular carcinoma. HCV antibody and HCV RNA testing are available diagnostic studies that offer high degree of accuracy. Current standard therapy includes a combination of pegylated interferon and ribavirin. Response rate is approximately 40% for genotype 1 and 80% for genotypes 2 and 3, respectively. Successful treatment can stop the progression of chronic liver disease, reduce the need for liver transplantation, and possibly decrease the risk for Hepatocellular carcinoma (HCC). Evaluating for potential treatment candidacy is an important initial step in the management of chronic HCV infection as not all individuals may need or qualify for the treatment. Understanding the natural history, the different diagnostic modalities, the current therapeutic options and, the treatment response and adverse effect profiles can help the practitioners better manage chronic HCV infection
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