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Propagation of interplanetary (IP) shocks, particularly those driven by coronal mass ejections (CMEs), is still an outstanding question in heliophysics and space weather forecasting. Here we address effects of the ambient solar wind on the propagation of two CME-driven shocks from Sun to Earth. The two CME-driven shock events (CME03: April 3, 2010 and CME12: July 12, 2012) have the following properties: (1) driven by a halo CME (i.e., source location is near Sun-Earth line), (2) a southern hemispheric CME source location, (3) similar propagation speed (e.g., took ~2 days reach the Earth), (4) occurred in the non-quiet solar period, and (4) leading to a severe geomagnetic storm. What is interesting is that the initial (near the Sun) propagation speed, as measured by coronagraph images, of CME03 was slower (~300 km/s) than CME12, but it took about same time for both events to reach the Earth. According to in-situ solar wind observations from Wind, the CME03-driven shock was associated with a faster solar wind upstream of the shock than the CME12. This is also demonstrated in our global MHD simulations. This study emphasizes the importance of the background solar wind in the propagation of CME-driven shocks. Not only the initial propagation speed near the Sun but also the ambient solar wind speed is the key to timing the arrival of CME events. The present study also demonstrated that global MHD simulations with realistic solar wind inputs is able to precisely predict the arrival of CME events.

Our new magnetohydrodynamics (MHD) simulation model of the solar corona and solar wind and its new capabilities are presented. This model covers the range of heliocentric distance from 2.5 solar radii (Rs) up to 1 AU and beyond. Starting the simulation from 2.5 Rs, our Sun-to-Earth MHD model can utilize straightforwardly the information on the coronal mass ejection (CME) and its associated magnetic flux rope at their earliest phase.This model is constructed by introducing the characteristic-based boundary treatment to our existing H3DMHD model [e.g. Wu+ (2015) JGR 121:1839]. The characteristic-based boundary treatment [e.g. Nakagawa+ (1987) A&Ap 197:354; Wu & Wang (1987) CMAME 64:267] can treat the temporal variations of MHD variables on the sub-sonic/Alfvenic boundary surface in a mathematically and physically consistent manner and enhances the computational robustness. In tailoring a set of characteristic equations for this new model, we assume that the coronal magnetic field is open to the interplanetary space and the solar coronal plasma is flowing outward everywhere at 2.5 Rs. Without the characteristic-based boundary treatment, we often fail to obtain the quasi-steady state of the solar corona and solar wind.This new model can introduce various types of the numerical perturbation mimicking the CME initiation to the quasi-steady state of the trans-sonic/Alfvenic solar wind. For example, an outward-moving and expanding CME structure can be introduced as the time-dependent boundary values by calculating the MHD variables of the CME structures on the 2.5-Rs intersection. In the present model, the characteristic-based boundary treatment is not used for the boundary grids the CME is passing through, for simplicity; although, it is possible to construct a new set of characteristic equations incorporating with the CME model.In this presentation, the details of the characteristic-based boundary treatment for the middle of the corona (hence, named CharM) are provided. The results of test simulations with various choices of parameters for the background steady trans-sonic/Alfvenic solar wind and the CME perturbations are compared to assess the dynamics of the CME evolution in the earliest period of the Sun-to-Earth disturbance propagation.

This work proposes the development of a system that will automatically evaluate quality honey bee queen species for breeding based on bee behavior. The queen breeding stages are set as the evaluati...

This study develops a novel fuzzy multi-objective decision system (FMODS) that uses the Simplex method, Access database technology and the JAVA programming language, for recoverable product of rema...

The heliospheric current sheet (HCS) is the largest known solar wind structure that exists persistently and continuously within the heliosphere. While it is discovered for more than half a century ago, owing to very limited and scattered in-situ solar wind observations in the heliosphere, the shape and evolution of the HCS are still little known and constitute the key subject in the study of global-scale solar wind. Currently the morphology of the HCS is derived largely from simple kinematic approaches that map the neutral sheet observed at 2.5 solar radii outward into the heliosphere. The dynamical effect of solar wind interactions on the evolution and global structure of the HCS is still poorly understood. Here we present results from a study of the HCS from 1995 to 2009 using time-dependent, three-dimensional, global magnetohydrodynamic (MHD) model simulations. We focus on the radial and solar cycle variations of the HCS tilt angle from 18 solar radii to 7 AU. We also compare our result with those obtained from ballistic outward projections of the neutral sheet observed at 2.5 solar radii. We present our analysis result and discuss possible implications.

Geomagnetic storms are one of the most important terrestrial space weather events and often commence in association with the arrival of coronal mass ejections (CMEs). When a CME is explosively released into the heliosphere, a shock wave can be formed in front of the dense, supersonic CME material. Thus, the first indication of the arrival of a CME at the Earth is a sudden increase in the global magnetic intensity due to magnetospheric compression by the CME-driven shock. Predictions of the arrival of the shock are a key element in space weather forecasting. Several different variety of methods, including numerical simulations, have been applied to predict the shock arrival time but with mediocre results, with an average uncertainty of ~10 hr. In this study we will use magnetohydrodynamic (MHD) simulations (Wu et al., 2020) to examine a number of input parameters such as the CME initial speed and release time in MHD simulation of CMEs and demonstrate their effect on the shock arrival time. We also explore effects of CME-CME interactions on the propagation of the CME/shock events. The multiple CME events that occurred during 6-29 July 2012 are simulated to highlight the importance of these factors on the prediction of shock arrival time using MHD simulations.

One of the important challenges in the field of space weather study is to predict the arrival time of the shocks associated with the interplanetary coronal mass ejections (ICMEs). In many Sun-to-Earth magnetohydrodynamic (MHD) simulations, a numerical perturbation mimicking the initial stage of the CME/ICME event is given at a position of corresponding coronal event in a steady state of the solar corona and/or solar wind. Then, the temporal evolution of the perturbed solar corona and solar wind are simulated. The numerical perturbation is a critical component in this kind of CME simulation model.Recently we have developed a new model suite combining our two existing MHD models, one is for the solar corona (Hayashi, 2005 ApJ 161:480) and the other is for solar wind (Wu+, 2012 Solar Physics 295:25; Wu+ 2020 JASTP 201:105211). In this model suite, plasma perturbations expressed with Gaussian spatial distribution and several parameters are given to initiate the CME/ICME simulation. For better simulating the Sun-Earth CME and ICME propagation, we made an iterative Newton-Raphson type minimization module for optimizing the perturbation parameters such that the differences in the CME speed within r < 30 Rsun and the arrival time of the CME-driven shocks at the Earth between the observation and simulation will be reduced simultaneously. We will report the results, in particular, which kinetic, thermal, and/or magnetic parameters are most important for numerically reproducing the ICMEs propagation from corona to 1 AU in this analysis study.

To meet specific customer demands, many new materials and recyclable components must be mixed into the production process in order to minimize total manufacturing costs and total lead time. The lot...

The steady states of the coronal magnetic field obtained with the magnetohydrodynamic (MHD) time-relaxation simulation model are examined. Our electric-field-driven model can introduce the three components of the solar surface magnetic field data maps as the boundary values of an MHD simulation, without violating the divergence-free condition of the magnetic field. The magnetic field in the simulated steady-state solar corona exhibits substantial nonpotentiality in the closed-field streamers. A few choices are allowed in our model, such as the criteria for determining whether or not the horizontal components at the weak-field region are included. The initial magnetic field configuration can be arbitrarily determined. In this work, we examined the differences between the steady states obtained with the information on the horizontal components and with several choices of the simulation setting, and compared the new steady states with those obtained without using the horizontal magnetic field components. We found that nonpotential magnetic structures in the derived steady states well correspond to the observed solar filament structures during a selected period of Carrington Rotation 2106. The difference in the steady state with different boundary treatments is found to be large. The difference caused by the initial magnetic configuration is found to be small.

Coronal mass ejections (CMEs) are a major source of solar wind disturbances that affect the space plasma and magnetic field environment along their propagation path. Accurate prediction of the arrival of a CME at Earth or any point in the heliosphere is still a daunting task. In this study we explore an often overlooked factor—the effects of “pre-events” that can alter the propagation of a CME due to a preceding CME. A data-driven magnetohydrodynamic numerical model is used to simulate the propagation of multiple CMEs and their driven shocks that occurred in 2012 July. The simulation results are validated with in situ solar wind plasma and magnetic field measurements at 1 au, testing the appropriateness of our simulation results for interpreting the CME/shock evolution. By comparing the simulation results with and without preceding CMEs, we find that the trailing CME can be accelerated by the “wake” of a preceding CME. A detailed analysis suggests that the acceleration is caused partially by an increase in the background solar wind and partially by the so-called “snowplow” effect, with the latter being the major contributor for the 2012 July event.

We present the simulation methodology and results of our new data-driven global coronal magnetohydrodynamics (MHD) simulation model. In this model, the solar-surface electric field is first calculated such that the curl will satisfy both the induction equation and the given temporal variations of the solar-surface magnetic field. We use the synoptic maps of the Helioseismic and Magnetic Imager three-component vector-magnetic-field data to specify the solar-surface magnetic-field vector for a period from Carrington Rotations (CRs) 2106 to 2110. A set of whole-Sun three-component electric-field maps are obtained for each CR transition interval of about 27.3 days. Using the inverted electric field as the driving variable, our new global coronal MHD model, with the angular resolution of π/64, can trace the evolution of the three-dimensional coronal magnetic field that matches the specified time-dependent solar-surface magnetic-field maps and simultaneously satisfies the divergence-free condition. A set of additional boundary treatments are introduced to control the contribution of the horizontal components of the magnetic field at the weak-field regions. The strength of the solar-surface magnetic field is limited to 20 Gauss for the sake of computational stability in this study. With these numerical treatments, the nonpotential coronal features, such as twisted loop structures, and their eruptive outward motions are obtained. This present model, capable of introducing three-component solar-surface magnetic-field observation data to coronal MHD simulations, is our first step toward a better model framework for the solar corona and hence solar wind.

Silent corticotroph staining pituitary adenoma (SCA) represents an uncommon subset of Non-Functioning adenomas (NFAs), hypothesized to be more locally aggressive. In this retrospective multicenter study, we investigate the safety and effectiveness of Stereotactic Radiosurgery (SRS) in patients with SCA compared with other non-SCA NFA’s. Eight centers participating in the International Gamma-Knife Research Foundation (IGKRF) contributed to this study. Outcomes of 50 patients with confirmed SCAs and 307 patients with confirmed non-SCA NFA’s treated with SRS were evaluated. Groups were matched. SCA was characterized by a lack of clinical evidence of Cushing disease, yet with positive immunostaining for corticotroph. Median age was 55.2 years (13.7–87). All patients underwent at least one trans-sphenoidal tumor resection prior to SRS. SRS parameters were comparable as well. Median follow-up 40 months (6–163). Overall tumor control rate (TCR) 91.2% (n = 280). In the SCA group, TCR were 82% (n = 41) versus 94.1% (n = 289) for the control-NFA (p = 0.0065). The SCA group showed a significantly higher incidence of new post-SRS visual deficit (p < 0.0001) assigned to tumor progression and growth, and post-SRS weakness and fatigue (p < 0.0001). In univariate and multivariate analysis, only the status of silent corticotroph staining (p = 0.005, p = 0.009 respectively) and margin dose (p < 0.0005, p = 0.0037 respectively) significantly influenced progression rate. A margin dose of ≥17 Gy was noted to influence the adenoma progression rate in the entire cohort (p = 0.003). Silent corticotroph staining represents an independent factor for adenoma progression and hypopituitarism after SRS. A higher margin dose may convey a greater chance of TCR.

A scheme was developed by Lepping, Berdichevsky, and Wu (Solar Phys., doi.10. 1007/ s11207-016-1040-9, 2017) [called the LBW article here] to approximate the average magnetic field magnitude (B-) profile of a "typical" magnetic cloud (MC) at/near 1AU. It was based on actual Wind MC data, taken over 21 years, that was used to modify a time shifted Bessel function (force-free) magnetic field, where shifted refers to a field that was adjusted for typical MC self-similar expansion. This was developed in the context of the Lepping, Jones, and Burlaga (J. Geophys. Res. vol. 95, p.11957, 1990) [called LJB here] MC parameter fitting model and should provide more realistic future representations of the MC's B-profile in most cases. In the LBW article, through testing, it was shown that on average it can be expected that in about 80% of the MC cases (but it varies according to the spacecrafts' actual closest approach distances) the modified model's B-profile of the MC should be significantly improved by use of this scheme. We describe how this scheme can be employed practically in modifying the LJB MC fitting model, and we test a new and slightly better (and less unwieldy) version of the scheme, the non-shifted (of Bessel functions) version, which is the one actually used in the LJB model modification. The new scheme is based on modification formulae that are slightly more accurate than the old scheme, and it is expected to improve the B-profile in approximately 83% of the cases on average. The schemes are applicable for use with data originating only at/near 1 AU, since the magnetic field and plasma data used in the development of the associated formulae were from only the Wind spacecraft, which was and is at 1 AU., accepted for publication in Solar Physics

Lawsonia inermis (Lythraceae) known as henna is one of the most popular and ancient plants used in cosmetics and hair dying. It is cultivated for its leaves but other parts such as seeds, flowers, stem bark and roots are also used in traditional medicine for millennia. Henna tattoo paste also proved to be beneficial for wound healing and in several skin diseases suggesting potent anti-inflammatory activity. To evaluate henna anti-inflammatory activity, 31 compounds, including three 1,5-diphenylpent-3-en-1-yne derivatives, lawsochylin A-C and three methyl naphthalene carboxylates, lawsonaphthoate A-C, were isolated from the stems and leaves of henna utilizing a bioassay-guided fractionation. The structures of the compounds were elucidated by spectroscopic data. Two compounds, lawsochylin A and lawsonaphthoate A showed potent anti-inflammatory activity by inhibition of superoxide anion generation (IC(50)=1.80 and 1.90 μg/ml) and elastase release (IC(50)=1.58 and 3.17 μg/ml) of human neutrophils in response to fMLP or cytochalasin B. Moreover, the known compounds, luteolin, apigenin, 4S-4-hydroxy-α-tetralone, and 2-butoxysuccinic acid, also showed potent inhibition of superoxide anion generation (IC(50)=0.75-1.78 μg/ml) and elastase release (IC(50)=1.62-3.61 μg/ml).

This study is motivated by the unusually low number of magnetic clouds (MCs) that are strictly identified within interplanetary coronal mass ejections (ICMEs), as observed at 1 AU; this is usually estimated to be around 30% or lower. But a looser definition of MCs may significantly increase this percentage. Another motivation is the unexpected shape of the occurrence distribution of the observers' "closest approach distances" (measured from a MC's axis, and called CA) which drops off somewhat rapidly as |CA| (in % of MC radius) approaches 100%, based on earlier studies. We suggest, for various geometrical and physical reasons, that the |CA|-distribution should be somewhere between a uniform one and the one actually observed, and therefore the 30% estimate should be higher. So we ask, When there is a failure to identify a MC within an ICME, is it occasionally due to a large |CA| passage, making MC identification more difficult, i.e., is it due to an event selection effect? In attempting to answer this question we examine WIND data to obtain an accurate distribution of the number of MCs vs. |CA| distance, whether the event is ICME-related or not, where initially a large number of cases (N=98) are considered. This gives a frequence distribution that is far from uniform, confirming earlier studies. This along with the fact that there are many ICME identification-parameters that do not depend on |CA| suggest that, indeed an MC event selection effect may explain at least part of the low ratio of (No. MCs)/(No. ICMEs). We also show that there is an acceptable geometrical and physical consistency in the relationships for both average "normalized" magnetic field intensity change and field direction change vs. |CA| within a MC, suggesting that our estimates of |CA|, BO (magnetic field intensity on the axis), and choice of a proper "cloud coordinate" system (all needed in the analysis) are acceptably accurate. Therefore, the MC fitting model (Lepping et al., 1990) is adequate, on average, for our analysis. However, this selection effect is not likely to completely answer our original question, on the unexpected ratio of MCs to ICMEs, so we must look for other factors, such as peculiarities of CME birth conditions. As a by-product of this analysis, we determine that the first order structural effects within a MC due to its interaction with the solar wind, plus the MC's usual expansion at 1 AU (i.e., the non-force free components of the MC's field) are, on average, weakly dependent on radial distance from the MC's axis; that is, in the outer reaches of a typical MC the non-force free effects show up, but even there they are rather weak. Finally, we show that it is not likely that a MC's size distribution statistically controls the occurrence distribution of the estimated |CA|s.

Recently developed adaptive charts have been shown to give substantially faster detection of most process shifts than the fixed parameters charts. The “sampling at fixed times” idea can be implemented in the adaptive control charts, and from the practical viewpoint, the adaptive charts with sampling at fixed times are considered to be more convenient to administer than the traditional adaptive charts. The usual assumption for designing the control chart is that the data or measurements are normally distributed. However, this assumption may not be tenable in some production processes. The Burr distribution has been used in the literature to represent various non-normal distributions. In the present paper, the Burr distribution is employed to evaluate the adaptive charts with sampling at fixed times for non-normal populations. Base on the study, it is shown that the variable sampling interval with fixed times (VSIFT) chart and variable sampling rate with fixed times (VSRFT) chart are very sensitive...

We develop a scheme for finding a "refined" front boundary-time (tB*) of an interplanetary magnetic cloud (MC) based on criteria that depend on the possible existence of any one or more of four specific solar wind features. The features that the program looks for, within ±2 h (i.e., the initial uncertainty interval) of a preliminarily estimated front boundary time, are: (1) a sufficiently large directional discontinuity in the interplanetary magnetic field (IMF), (2) a significant proton plasma beta (βP) drop, (3) a significant proton temperature drop, and (4) a marked increase in the IMF's intensity. Also we examine to see if the "MC-side" of the boundary has a MC-like value of βP. The scheme was tested using 5, 10, 15, and 20 min averages of the relevant physical quantities from WIND data, in order to find the optimum average to use. The 5 min average, initially based on analysis of N=26 carefully chosen MCs, turned out to be marginally the best average to use for our purposes. Other criteria, besides the four described above, such as the existence of a magnetic hole, plasma speed change, and/or field fluctuation level change, were examined and dismissed as not reliable enough, or usually associated with physical quantities that change too slowly around the boundary to be useful. The preliminarily estimated front boundary time, tB, and its initial ±2-h uncertainty interval are determined by either an automatic MC identification scheme or by visual inspection. The boundary-scheme was developed specifically for aiding in forecasting the strength and timing of a geomagnetic storm due to the passage of a MC in real-time, but can be used in post ground-data collection for imposing consistency when choosing front boundaries of MCs. This scheme has been extensively tested, first using 81 bona fide MCs, collected over about 8.6 years of WIND data (at 1 AU), and also by using 122 MC-like structures as defined by Lepping et al. (2005) over about the same period. Final statistical testing of the 81 MCs to see how close the refined boundary-time tB* lies with respect to a preliminary time tB(VI) was carried out, i.e., to find Δt1=(tB*–tB(VI)), for the full set of MCs, where tB(VI) is usually a very accurate time previously determined from visual inspection, This testing showed that 59 Δt1s (i.e., 73%) lie within ±30 min, 71 Δt1s (i.e., 88%) lie within ±45 min, and only 5 cases lie outside a |Δt1| of 1.0 h, which is only 6% of the full 81, and these 6% would be considered unsatisfactory. Since MC parameter fitting is usually done on the basis of 30 or 60 min averages, these results seem quite satisfactory. The program for this front boundary estimation scheme is located at the Website: http://wind.nasa.gov/mc/boundary.php.

In the present paper, a decision model is developed for producers in the static demand market to determine the optimal price, warranty length and production rate of a product to maximize profit based on the pre-determined life cycle. The free renewal warranty policy is considered under which failed products are renewed before the end of warranty length at no cost to consumers. The expected number of renewals based on warranty length is derived for Weibull life distributed products. The objective function includes both demand and cost functions, where production cost, warranty cost and inventory cost are involved. A solution approach using the maximum principle is described, and is applied to two specific cases of markets. The first case of market considers positive discount rate, and the second case of market considers zero discount rate. The economic sensitivity analysis is conducted to evaluate the effect of model parameters on the optimal solution. Some conclusions are drawn based on the sensitivity analysis.

The present paper provides a theoretical development and empirical study on determining price, warranty length and production rate in the static sales market, where word of mouth is not important. For the theoretical development, we present the decision model of determining the optimal price, warranty length and production rate of a product such that the present value of the product profit may be maximized. The empirical study aims at choosing among the alternative model specifications and assessing the shapes of the sales rate function. The sales rate functions are estimated by nonlinear regression, and then are tested by using battery sales data as input while price, warranty length and production rate as outputs. Results of the empirical study are consistent with the corresponding theoretical predictions and consequently show the applicability of the decision model.

In recent years remarkable advances have been made in the development of physics based models of various parts of the solar-terrestrial system (see JASTP special issues, October, November 2004; February 2007). In this paper, we focus our discussions in a specific region of the Sun to the Earth’s environment (i.e. 1 AU). It is well-known that geomagnetic storms are caused by solar eruptions. The consequences of these storms include particle acceleration, solar wind impact on the Earth’s magnetosphere and ionosphere, UV-EUV radiation effects on the lower atmosphere, etc. One of the main challenges is to predict the arrival time at 1 AU of the solar disturbance. The prospects look good for an accurate, real-time forecast scheme built on the acquisition of solar, heliosphere and the near-Earth data and large-scale models. However, the accuracy of these models still needs improvement. We will discuss the present status of the models and challenges to improve the simulation models.

Starting with a large number (N = 100) of Wind magnetic clouds (MCs) and applying necessary restrictions, we find a proper set of N = 29 to investigate the average ecliptic plane projection of the upstream magnetosheath thickness as a function of the longi- tude of the solar source of the MCs, for those cases of MCs having upstream shock waves. A few of the obvious restrictions on the full set of MCs are the need for there to exist a driven upstream shock wave, knowledge of the MC's solar source, and restriction to only MCs of low axial latitudes. The analysis required splitting this set into two subsets according to av- erage magnetosheath speed: slow/average (300 - 500 km s −1 ) and fast (500 - 1100 km s −1 ) speeds. Only the fast set gives plausible results, where the estimated magnetosheath thick- ness (�S) goes from 0.042 to 0.079 AU (at 1 AU) over the longitude sector of 0° (adjusted source-center longitude of the average magnetic cloud) to 40° off center (East or West), based on N = 11 appropriate cases. These estimates are well determined with a sigma ( σ) for the fit of 0.0055 AU, where σ is effectively the same as √ (chi-squared) for the appro- priate quadratic fit. The associated linear correlation coefficient forS versus |Longitude| was very good (c.c. = 0.93) for the fast range, andS at 60° longitude is extrapolated to be 2.7 times the value at 0°. For the slower speeds we obtain the surprising result thatS is typically more-or-less constant at 0.040 ± 0.013 AU at all longitudes, indicating that the MC as a driver, when moving close to the normal solar wind speed, has little influence on magnetosheath thickness. In some cases, the correct choice between two candidate solar- source longitudes for a fast MC might be made by noting the value of the observedS just

The ionospheric total electron content (TEC) in the northern hemispheric equatorial ionospheric anomaly (EIA) region is studied by analyzing dual-frequency signals of the Global Position System (GPS) acquired from a chain of nine observational sites clustered around Taiwan (21.9–26.2°N, 118.4–112.6°E). In this study, we present results from a statistical study of seasonal and geomagnetic effects on the EIA during solar cycle 23: 1994–2003. It is found that TEC at equatorial anomaly crests yield their maximum values during the vernal and autumnal months and their minimum values during the summer (except 1998). Using monthly averaged I c (magnitude of TEC at the northern anomaly crest), semi-annual variations is seen clearly with two maxima occurring in both spring and autumn. In addition, I c is found to be greater in winter than in summer. Statistically monthly values of I c were poorly correlated with the monthly Dst index ( r = −0.22) but were well correlated with the solar emission F 10.7 index ( r = 0.87) for the entire database for the period during 1994–2003. In contrast, monthly values of I c were correlated better with Dst ( r ⩾ 0.72) than with F 10.7 ( r ⩽ 0.56) in every year during the low solar activity period (1994–1997). It suggests that the effect of solar activity on I c is a longer term (years), whereas the effect of geomagnetic activity on I c is a shorter term (months).

We study an unusual solar energetic particle (SEP) event that was associated with the coronal mass ejection (CME) on March 15, 2013. Enhancements of the SEP fluxes were first detected by the ACE spacecraft at 14:00 UT, ∼7 hours after the onset of the CME (07:00 UT), and the SEP’s peak intensities were recorded ∼36 hours after the onset of the CME. Our recent study showed that the CME-driven shock Mach number, based on a global three-dimensional (3-D) magnetohydrodynamic (MHD) simulation, is well correlated with the time-intensity of 10-30 MeV and 30-80 MeV protons. Here we focus on the radial dependence (r−α) of 4He (3.43-41.2 MeV/n) and O (7.30-89.8 MeV/n) energetic particles from ACE/SIS. It is found that the scaling factor (α) ranges between 2 and 4 for most of the energy channels. We also found that the correlation coefficients tend to increase with SEP energies.

The unusual low solar wind density and weak magnetic field observed at the near-Earth orbit during the 2007-2009 solar minimum years has been an actively studied subject. Our previous numerical simulation suggested that an inflation of the heliosphere current/plasma sheet (HCS/HPS) could be the cause of the density and field anomaly [1]. The inflation of HCS/HPS hypothesizes that HCS/HPS is thicker if Sun’s polar magnetic field is weaker and thinner if Sun’s polar magnetic field is stronger. In this study, we provide additional evidence to support this hypothesis using photosphere magnetographs from the ground-based stations (NSO, MWO or WMO). Specifically, we compute and compare average values of the solar magnetic field for two different periods: 1995-1997 and 2007-2009. We also integrate the magnetic field over the equatorial (< 7.5°), the polar (47.5°-87.5°), and the mid-latitude (12.5°-42.5°) regions. It is found that at 2.5 solar radii the averaged radial-component of the magnetic field (Br) is smaller in the 2007-2009 period than in the 1995-1997 period by ∼33% in the polar region, ∼36% in the mid-latitude region, and ∼11% in the equatorial region. When moving outward with the solar wind, the relatively large magnetic field at the equator may inflate the HCS/HPS at a farther distance causing the unusually low solar wind density and weak magnetic field at the equator during 2007-2009.

Using nine years of solar wind plasma and magnetic field data from the Wind mission, we investigated the characteristics of both magnetic clouds (MCs) and magnetic cloud-like structures (MCLs) during 1995 – 2003. A MCL structure is an event that is identified by an automatic scheme (Lepping, Wu, and Berdichevsky, Ann. Geophys.23, 2687, 2005) with the same criteria as for a MC, but it is not usually identifiable as a flux rope by using the MC (Burlaga et al., J. Geophys. Res.86, 6673, 1981) fitting model developed by Lepping, Jones, and Burlaga (Geophys. Res. Lett.95(11), 957, 1990). The average occurrence rate is 9.5 for MCs and 13.6 for MCLs per year for the overall period of interest, and there were 82 MCs and 122 MCLs identified during this period. The characteristics of MCs and MCL structures are as follows: (1) The average duration, Δt, of MCs is 21.1 h, which is 40% longer than that for MCLs (Δt=15 h); (2) the average \(B_{z_{\min}}\) (minimum Bz found in MC/MCL measured in geocentric solar ecliptic coordinates) is −10.2 nT for MCs and −6 nT for MCLs; (3) the average Dstmin (minimum Dst caused by MCs/MCLs) is −82 nT for MCs and −37 nT for MCLs; (4) the average solar wind velocity is 453 km s−1 for MCs and 413 km s−1 for MCLs; (5) the average thermal speed is 24.6 km s−1 for MCs and 27.7 km s−1 for MCLs; (6) the average magnetic field intensity is 12.7 nT for MCs and 9.8 nT for MCLs; (7) the average solar wind density is 9.4 cm−3 for MCs and 6.3 cm−3 for MCLs; and (8) a MC is one of the most important interplanetary structures capable of causing severe geomagnetic storms. The longer duration, more intense magnetic field and higher solar wind speed of MCs, compared to those properties of the MCLs, are very likely the major reasons for MCs generally causing more severe geomagnetic storms than MCLs. But the fact that a MC is an important interplanetary structure with respect to geomagnetic storms is not new (e.g., Zhang and Burlaga, J. Geophys. Res.93, 2511, 1988; Bothmer, ESA SP-535, 419, 2003).

In this work we consider an optimization method to image file compression based on fuzzy logic. This optimization is realized thanks to wavelet transform in a pre-compression phase. Thanks to this approach in the pre-processing phase the wavelet transform is used to fix some relevant parameters like as the best compression box and other tolerance parameter (locally defined). With respect to the traditional approach by using wavelet this method is better from time consuming point of view. While with respect to a standard fuzzy logic approach the presented method has the advantage to perform compression with different ratio on different box optimized with respect to each subimage.

We use a one-dimensional, time-dependent adaptive grid MHD code to study the evolution of shocks (both slow and fast shocks) from the surface of the Sun through the heliosphere. In order to achieve the goal, we track a specific solar event's plasma and magnetic field output as it propagates into interplanetary space with a possible geoeffective consequence. We have chosen the famous event of the October/November (“Halloween 2003”) epoch which produced two of the largest geomagnetic storms during solar cycle 23, followed by the arrivals of the shocks at Earth. These two geomagnetic storms are associated with two of these flares (X17/4B and X10/2B). Accordingly, four separate pressure pulses, at the appropriate times and with different strengths and duration, determined via a trial and error procedure, are introduced on the Sun to mimic the four flares. The results show that the simulated solar wind velocity temporal profiles successfully matched the observations at L1. The propagation speed of shock waves near the Sun also matched with the CME observations of SOHO/LASCO. The major objective, to demonstrate the detailed nature of interacting shocks and some of their products after origination from closely spaced solar events, is achieved. The evolution of both slow and fast shocks is also discussed in detail.

A user-friendly, real-time, observation-driven system for forecasting solar wind and interplanetary magnetic field conditions is described. The forecast system presently uses the Hakamada–Akasofu–Fry (version 2) kinematic solar wind model to predict, in real-time, solar wind conditions in the heliosphere, including at the location of Mars, and beyond. Properly characterizing and predicting this region of the space environment are essential steps towards improving the accuracy of “downstream” space weather models used to forecast the space radiation environment and geomagnetic activity. Representative modeling results are presented and the conclusion is made that uncertainty in determining the physical parameters needed for model inputs from real-time solar observations is the biggest factor limiting the accuracy of solar wind models used for space weather analysis and prediction. Future directions include extending the forecast system via a hybrid approach to include 3D MHD modeling.

This study performs simulations of interplanetary coronal mass ejection (ICME) propagation in a realistic three-dimensional (3D) solar wind structure from the Sun to the Earth by using the newly developed hybrid code, HAFv.2+3DMHD. This model combines two simulation codes, Hakamada–Akasofu–Fry code version 2 (HAFv.2) and a fully 3D, time-dependent MHD simulation code. The solar wind structure is simulated out to 0.08 AU (18 Rs) from source surface maps using the HAFv.2 code. The outputs at 0.08 AU are then used to provide inputs for the lower boundary, at that location, of the 3D MHD code to calculate solar wind and its evolution to 1 AU and beyond. A dynamic disturbance, mimicking a particular flare’s energy output, is delivered to this non-uniform structure to model the evolution and interplanetary propagation of ICMEs (including their shocks). We then show the interaction between two ICMEs and the dynamic process during the overtaking of one shock by the other. The results show that both CMEs and heliosphere current sheet/plasma sheet were deformed by interacting with each other. � 2007 Published by Elsevier Ltd on behalf of COSPAR.

Control charting is a graphical expression and operation of statistical hypothesis testing. In this article, we develop the joint economic design of the variable sampling intervals (VSI) and R charts to determine the values of the seven test parameters of the charts (i.e., the sample size, the long sampling interval, the short sampling interval, the warning limits of the chart, the control limits of the chart, the warning limit of the R chart, and the control limit of the R chart) such that the expected total cost associated with the test procedure is minimized. The genetic algorithm (GA) is employed to search for the optimal values of the seven test parameters of the VSI and R charts, and an example is provided to illustrate the solution procedure. A sensitivity analysis then is carried out to investigate the effects of cost and model parameters on the solution of the joint economic design.

In this paper, a decision model is presented for manufacturing firms to determine the optimal price and warranty length to maximize profits based on the pre-determined life cycle. We consider the free renewal warranty policy under which failed items are renewed free of charge until a specified total operating time has been achieved. The expected number of renewals based on the warranty length is derived for a normal lifetime distributed product and the total cost of production and providing warranty is evaluated. A solution approach using the maximum principle is described, and is applied to two specific types of markets. The first type of market considers the case of static sales rate function with a positive discount rate, and the second type of market considers the case of separable sales rate function with a zero discount rate. A sensitivity analysis is conducted to evaluate the effect of model parameters on the optimal solution. Some conclusions are drawn based on the sensitivity analysis.

The purpose of this parametric study is to predict the arrival time at Earth of shocks due to disturbances observed on the Sun. A 3D magnetohydrodynamic (MHD) simulation code is used to simulate the evolution of these disturbances as they propagate out to 1 AU. The model in Han, Wu and Dryer (1988) uses solar data for input at 0.08 AU (18 solar radii). The initial shock speed (ISS) is assumed to be constant from the corona to 0.08 AU. We investigate how variations of this ISS affect the arrival times of the shock at Earth. This basic parametric study, however, does not consider inhomogeneous background solar wind structures such as corotating interaction regions and their precursor stream–stream interactions, nor interplanetary manifestations of complex coronal mass ejecta such as magnetic clouds. In the latter case, only their associated shocks are considered. Because the ambient (pre-existing background) solar wind speed is known to affect the shock arrival time at 1 AU, we also simulated events with various background solar wind speeds (BSWS) to investigate this effect. The results show that the shock arrival time at Earth depends on the BSWS, the speed of solar disturbances, their size, and their source location at the Sun. However, it is found that for a sufficiently large momentum input, the shock arrival time at Earth is not significantly affected by the pre-existing solar wind speed.