Backwardation Research Articles

Normal backwardation is normal

Normal backwardation is normal

Recent progress on TRIAM-1M

A steady state plasma with high performance and high current drive efficiency is reported. In 2.45 GHz LHCD plasmas Ti is studied as a function of ne at the edge of the high ion temperature (HIT) window. Different characteristic timescales are found for Ti and ne to enter the HIT regime and the observed hysteresis behaviour of Ti with respect to ne is attributed to this difference. The electromagnetic emission (<3.5 GHz) is studied in order to understand ion heating mechanisms in the HIT regime. The spectrum shows several sidebands whose peak frequencies correspond to the ion plasma frequency. The spectral narrowing of the width of the sideband shows a clear correlation with ion heating. In 8.2 GHz LHCD plasmas an enhanced current drive (ECD) regime where both current drive efficiency ηCD( = n̄eICDR0/PLH ∼1 × 1019 A m-2/W) and energy confinement time τE (∼8-10 ms) are simultaneously improved is obtained at an n̄e of 4.3 × 1013 cm-3 and B = 7 T under full current drive conditions. There exists a certain threshold power above which the ECD transition occurs. A hysteresis of ηCD is found around the threshold power, which is explained by the different characteristic time for the ECD transition in power rampup and rampdown schemes. Current profile control experiments are performed by using two opposite travelling LHWs. Current compensation (ΔICD/ICD < -10%) is clearly seen when the backward (BW) travelling LHW (8.2 GHz) is added to a target plasma whose current is driven by a forward travelling LHW (8.2 GHz). As the BW wave power is increased, however, the current tends to flow in the forward direction. The mechanisms of this non-linear behaviour of the driven current with respect to the BW wave power are discussed.

Normal backwardation is normal

Traditionally, constant expected return asset pricing models are used to assess the presence of a futures risk premium and the validity of the normal backwardation theory. In the light of recent evidence regarding the presence of time variation in expected futures returns, such an approach may lead to incorrect inferences on the applicability of the Keynesian hypothesis. This article therefore allows for variation through time in expected futures returns and offers some strong evidence in favor of the normal backwardation and contango theories. © 2000 John Wiley & Sons, Inc. Jrl Fut Mark 20:803–821, 2000

My transforming peak experience was diagnosed as paranoid schizophrenia.

A clinical psychologist reveals how a breakthrough, transformational experience was perceived as a schizophrenic breakdown and led to his being placed on the back ward of a VA psychiatric hospital.

The Impossibility of Full Carry Markets

The theories for the existence of futures markets, that of supply of storage, and normal backwardation, allow for the possibility of the relationship between futures and spot being at full carry under certain conditions (very high level of inventories for the former, and net short hedging equaling net long hedging in the latter). Using arbitrage arguments, it is shown that a market at full carry provides a free option to the cash and carry trader. The assumption of arbitrage free markets rules out the possibility of the existence of a free option. Since this option will be priced in the spread between the spot and futures prices, efficient markets preclude the existence of a full carry market. Regression and cointegration tests are used to show that the futures-spot relationship includes an option component.

Eye-head coordination for the steering of locomotion in humans: an anticipatory synergy

We investigated head and gaze orientation in six healthy volunteers walking along 90° corner trajectories, both at light and with eyes closed. We found that head and eyes systematically deviated toward the future direction of the curved trajectory. Anticipation lead was about 1 s. Strikingly, the same behaviour was observed in darkness. In backward (BW) locomotion along the trajectory (from end- to start-point), gaze deviated toward the opposite direction, such that the forward locomotor pattern did not appear time-reversed. Orienting movements displayed higher amplitude, reproducibility and time lead in the forward (FW) direction at light. We suggest that anticipatory orienting synergies belong to the behavioural repertoire of human navigation and may reflect the need to prepare a stable reference frame for intended action.

A Strategic Analysis of Corners and Squeezes

We develop a dynamic game-theoretic model of a futures market in which prices can be manipulated by corner and squeeze. We investigate equilibrium trading strategies and the price dynamics these strategies produce. Price paths produced by our model can mimic observed prices for potentially comerable commodities and explain the volatility of certain prices even when no manipulations occur. Our model also generates occasional apparent price bubbles and accounts for the existence of normal backwardation in futures markets even when players are risk neutral.

Convenience yield and the option to liquidate for commodities with a crop cycle

In this paper we present a simple model which explains convenience yields in line with Keynes' 'liquid stocks' theory. When the flows of demand and production of a commodity are not synchronised, stored inventories are the source of supply which absorbs demand fluctuations in periods between production times. Since negative storage is not possible, the likelihood of a stockout implies that spot price may rise above futures price between production times. We show that the yield on stored commodities has the payoff structure of a call option. Furthermore, the existence of this call option acts to counter the appearance of normal backwardation in futures prices. Empirical tests on four commodities offer supportive evidence of our theory. Copyright 1997 by Oxford University Press.

Normal backwardation in short-term interest rate futures markets

Normal backwardation in short-term interest rate futures markets

Adaptive control for backward quadrupedal walking V. Mutable activation of bifunctional thigh muscles.

1. In this, the fifth article in a series to assess changes in posture, hindlimb dynamics, and muscle synergies associated with backward (BWD) quadrupedal walking, we compared the recruitment of three biarticular muscles of the cat's anterior thigh (anterior sartorius, SAa; medial sartorius, SAm; rectus femoris, RF) for forward (FWD) and BWD treadmill walking. Electromyography (EMG) records from these muscles, along with those of two muscles (semitendinosus, ST; anterior biceps femoris, ABF) studied previously in this series, were synchronized with kinematic data digitized from high-speed ciné film for unperturbed steps and steps in which a stumbling corrective reaction was elicited during swing. 2. During swing, the relative timing of EMG activity for the unifunctional SAm (hip and knee flexor) was similar for unperturbed steps of FWD and BWD walking. The SAm was active before paw lift off and remained active during most of swing (75%) for both forms of walking, but there was a marked decrease in EMG amplitude after paw off during BWD and not FWD swing. In contrast, the relative timing of EMG activity for the SAa and RF, two bifunctional muscles (hip flexors, knee extensors), was different for FWD and BWD swing. During FWD swing, the SAa and the RF (to a lesser extent) were coactive with the SAm; however, during BWD swing, the SAa and RF were active just before paw lift off and then inactive for the rest of swing until just before paw contact (see 3). Thus the swing-phase activity of the SAa and RF was markedly shorter for BWD than FWD swing. 3. Activity in SAa and RF was also different during FWD and BWD stance. The RF was consistently active from mid-to-late stance of FWD walking, and the SAa was also active during this period in some FWD steps. During the stance phase of BWD walking, however, the onset of activity in both muscles consistently shifted to early stance as both muscles became active just before paw contact (the E1 phase). Activity in RF consistently persisted through most of BWD stance. The duration of SAa recruitment during BWD stance was more variable across cats with offsets ranging from mid- to late stance. 4. The activation patterns of the biarticular anterior thigh muscles during stumbling corrective reactions were, in general, similar to their different activations during FWD and BWD swing. The initial response to a mechanical stimulus applied to the dorsum of the paw that obstructed FWD swing was an augmentation of knee flexion and increased activity in ST and SAm. A mechanical stimulus applied to the ventral surface of the paw to obstruct BWD swing resulted in an initial conversion of hip extension to flexion and a slowing of knee flexion. There was a corresponding recruitment of SAa and RF and an enhancement of background activity in SAm. 5. The two forms of walking are differentiated by posture and limb dynamics, yet muscles participating in the basic flexor and extensor synergies are unchanged. Although central pattern generating (CPG) circuits determine the basic timing of these synergies, changes in the duration and waveform of muscle activity may depend on unique interactions among the CPG, supraspinal inputs that set posture and the animal's goal (to walk BWD or FWD) and motion-related feedback from the hindlimb. Output mutability to each muscle may depend on the balance of this tripartite input; muscles with immutable patterns may rely heavily on input from CPG circuits, whereas muscles with mutable patterns may rely more on form-specific proprioceptive and supraspinal inputs.

Adaptive control for backward quadrupedal walking VI. metatarsophalangeal joint dynamics and motor patterns of digit muscles

1. We compared the dynamics of the metatarsophalangeal (MTP) joint of the cat's hind paw and the motor patterns of two short and four long muscles of the digits for two walking forms, forward (FWD) and backward (BWD). Kinematic (angular displacements) data digitized from high-speed ciné film and electromyographic (EMG) data were synchronized and assessed for bouts of treadmill walking. Kinetic data (joint forces) were calculated from kinematic and anthropometric data with the use of inverse-dynamic calculations in which the MTP joint net torque was divided into gravitational, motion-dependent, ground contact (absent for swing), and muscle torque components. Swing-phase kinetics were calculated from treadmill steps and stance-phase kinetics from overground steps in which one hind paw contacted a miniature force platform embedded in the walkway. 2. The plantar angle at the intersection of the metatarsal and phalangeal segmental lines was used to measure MTP angular displacements. During swing for both walking forms, the MTP joint flexed (F) and then extended (E); however, the F-E transition occurred at the onset of FWD swing and at the end of BWD swing. For FWD walking, the MTP joint extended at a constant velocity during most of stance as the cat's weight rotated forward over the paw. During the unweighting phase at the end of stance, the MTP joint flexed rapidly before paw lift off. For BWD walking, the MTP joint extended briefly at stance onset (similar to a yield) and then flexed at a constant velocity as the cat's weight rotated backward over the paw. At the end of stance, the MTP joint extended and then flexed slightly as the paw was unweighted before paw lift off. 3. For both forms of walking, three of the six muscles tested were recruited just before paw contact and remained active for most (75-80%) of stance for both walking forms: plantaris (PLT), flexor hallucis longus (FHL), and flexor digitorum brevis (FDB). Their recruitment contributed to the flexor muscle torque at the MTP joint during most of FWD and BWD stance and was responsible for the absorption of mechanical power at the MTP joint for FWD stance and generation of mechanical power at the MTP joint during BWD stance. Also, the FHL and PLT, along with the soleus (SOL; also recorded in this study), contributed to an extensor muscle torque (described in paper IV of this series) and the generation of mechanical power at the ankle joint during stance of FWD and BWD walking. 4. The timing of activity for three muscles recruited during FWD swing was distinct for the two walking forms. The hallmark burst of the flexor digitorum longus (FDL)--a single burst, brief in duration and high in amplitude--occurred at the end of FWD swing (as the toes flexed rapidly) but shifted to the onset of BWD stance (as the claws protruded and toes extended) during paw weighting. The extensor digitorum longus (EDL) was recruited after paw off and was active for most of FWD swing; its activity contributed to an extensor muscle torque at the MTP joint and a flexor muscle torque at the ankle joint. For BWD walking, EDL recruitment shifted to an earlier phase in the step cycle and coincided with toe extension, which occurred at the end of stance before paw lift off. This pre-lift off activity continued into the first part of swing and contributed to an extensor muscle torque at the MTP joint and a flexor muscle torque at the ankle.(ABSTRACT TRUNCATED AT 250 WORDS)

ロータリ耕うん装置への土壌付着防止対策に関する研究

Even it is to be preferable that no soil adhesion may happen to the rotary tiller, difficulties on ways for getting perfect stoppage on the soil adhesion are existed, nowadays. Therefore, studies on how to remove the soil adhesion on the rotary tiller and structural development for decreasing the soil adhesion are necessary.The authors examined and discussed on the amount of soil adhesion to every parts of the machines in this study, using the up-cut type rotary that is possible to make various combinations, as steel covers, gum covers, commercial tines, inverted tines (making blade on back ward) and high-polyethylene tines (sticking of high-polyethylene sheet) and etc. In addition, on factors influencing to the adhered soil onto the rotary tillers, the statistical analysis was done by the quantification I. The results were as follows.(1) By the comparative examinations between the steel cover and the gum cover, it was proved that the separation of the adhered soil appeared in a case of the gum cover. This indicated the effect for a counter measure of soil adhesion by giving vibration of contacted tillage tines onto the gum cover.(2) Small differences on the comparative soil adhesion of various parts between combinations of the converted tines and the commercial tines were recognized, and the same effects was taken at two examination (Fig. 5, Fig. 8). But the soil adhesion of gum cover side was less than the commercial tines side in three measure point on some examination (Fig. 8).(3) When comparisons were made on high-polyethylene tines and commercial tines with low moisture contents (37.9-49.8%) of soils, the soil adhesion to the high-polyethylene tines showed in low values compared with commercial tines in every measured places. But the falling off polyethylene sheets sticked on high-polyethylene tines was recognized at about 110m of the tillage, when moisture contents of soils was fairly high (57.8-62.8%). Therefore, the further and perfect methods on the sticking of the polyethylene sheet to tines is needed, in the future.(4) By results on the statistical analysis of moisture contents of soils, organic matter contents of soils, distance of tillage, kinds of covers and kinds of tines by quantification I, big influences in factors to the soil adhesion by organic matter contents of soils and conditions of operations were observed and also the strongest influence was found by the cover of the rotary tiller in the machines and following these, the tillage tines had a role.(5) When results of this experiment was summarized, the best way is presumed that operations with both the gum cover and high-polyethylene tines as a counter measure of the stoppage of the soil adhesion to the tillage is made, after the settlement of problems on the falling-off sticked polyethylene sheet from high-polyethylene tines.

Process Development to Form Net-Shape Nosing Shells by the Backward Tracing Scheme of the Rigid-Plastic FEM and Its Experimental Confirmation

A preform is designed by the backward tracing scheme of the rigid-plastic finite element method(FEM) for net-shape shell nosing components without machining after forming. The current process of the shell nosing requires cost-consuming machining to produce final products. Here, the backward tracing scheme of the rigid-plastic FEM, a novel method for preform design of metal forming processes, derives a sound preform for net-shape shell nosing product. The current process is simulated by the rigid-plastic finite element analysis to check the metal flow involved in the forming with a trial preform and its modified preform. The two preforms are found to be inadequate for net-shape shell nosing product. The first application of the back ward tracing scheme derives a preform producing a not-shape shell nosing product. The first application of the backward tracing scheme derives a preform producing a net-shape product numerically, but it is difficult to be formed economically as a preform. Thus an improved preform is designed by the badkward tracing scheme, which is suitable for net-shape manufacturing of the shell nosing components in view of economy of production and forming characteristics of the product. The preform in the current process and a modified preform are confirmed by a series of experiments and the results give the same deformation with the numerical ones. Finally the newly designed preform by the FEM was experimentally proved to be adequate in obtaining net-shape products.

S&amp;P 500 futures market and the normal backwardation hypothesis

This paper examines the behavior of near term S&P 500 index futures contract prices in the context of the theory of normal backwardation. Daily S&P 500 futures prices for 41 contracts over the 1982–1992 period are examined. There is no evidence that S&P 500 futures prices are biased estimates of the expected future spot price on expiration. Daily futures prices usually lie below the expected future spot price on expiration and usually rise over the contract period, but these price movements are not statistically significant. The surprising result of this study is the number of observations where backwardation appears not to hold. Furthermore, changes in the U.S. dollar exchange rates, the Tax Reform Act of 1986 and the switching of S&P 500 contracts quarterly expiration day had no significant effect on the behavior of S&P 500 futures prices.

Clozapine in the back wards.

Most reports of clozapine in treatment-refractory patients have dealt with outpatient and/or relatively less chronic samples. This report focuses on clinical outcome in an institutionalized sample, notable for chronicity, poor functioning, and representing the extreme segment of the treatment-refractory population. We analyzed the data for 50 persistently hospitalized patients referred for clozapine treatment in open trials. Dimensions of outcome assessed at baseline and periodically thereafter included psychopathology, cognitive performance, extrapyramidal side effects (EPS), and patient satisfaction. Certain features of clozapine response in institutionalized patients have been underemphasized (e.g., reduced use of restraint and seclusion, greater social interaction, reduced cost for care). Ninety-four percent of this sample showed some form of improvement with clozapine. Improvement ranged from modest (e.g., less EPS) to remarkable (e.g., discharge). An adequate clozapine trial may require more than 6 months.

Information and Normal Backwardation as Determinants of Trading Performance: Evidence From the North Sea Oil Forward Market

This paper utilizes transaction-specific data on forward trading in the international petroleum market to test directly predictions from the theory of normal backwardation against information-based predictions of trader performance. With the ability to identify buyers and sellers, the authors find that no traders make significant profits on interday measures. Within the day, however, traders likely to have superior information make significant profits. The results are not supportive of normal backwardation but are consistent with the time pattern of information dissemination in this market--deals made during the day are widely reported only at day's end. Copyright 1994 by Royal Economic Society.

Rudolf Arnheim: A clinician of images

I met Rudolf Arnheim in April 1971 when he was teaching at Harvard University and I was a 24-yearold art therapist at Danvers State Hospital north of Boston. I had just been admitted into the Goddard College masters program. Goddard had a new independent study system that emphasized field experience and individualized study coordinated by a Goddard professor and a mentor selected by the student. Although my psychiatric supervisors were skilled and helpful guides in the treatment of patients, they knew nothing about art and creative arts therapy. I needed an advisor who could help me clinically underst~d what art does in therapy and I desired a relationship with someone who was interested in the broad philosophy, history and psychology of creative expression. I sent for the catalogues of all the local colleges and universities-Boston College, Boston University, Brandeis, Harvard, The School of the Museum of Fine Arts, Tufts, Wellesley-and wrote to professors teaching art, aesthetics and even art history. I must have written to 20 people. Amheim and his books were in a league of their own not only in Boston but in the world that recognized him as the century’s foremost authority on the psychology of art. He had a special professorship at Harvard’s Carpenter Center for the Visual Arts. I felt there was no chance of interesting Rudolf Amheim in what I was doing on the back wards of a state hospital. And why would an eminent professor at Harvard want to do anything with an irregular student from a tiny and most irregular experimental college? I said to myself, “It can’t hurt to send a letter.” I felt that, though I was overstepping my station in life, there was no harm in trying a Hail Mary pass through the mail. Little did I know how unlike the stereotypic “eminent professor” Rudolf Amheim would turn out to be. His lifework was more sympathetic to my divergent interests than I realized at the time. His own career and vision of integrating the completely separate professions of art and scientific psychology were no more unusual than my attempts to link different disciplines. To this day it amazes me that Amheim was the only person who answered my letter. The first of many lessons I learned from Rudolf Amheim concerns responding to mail. I don’t measure up to his standard as a coKes~ndent, but whenever someone writes and soulfully describes what they are doing in their work, I try to reply, guided by the memory of what he did for me. When I first visited Amheim at Harvard he made a point of introducing me to the Carpenter Center complex designed by Le Corbusier and completed in 1963. The building appeared to be an intimate friend, a living thing for Amheim whose office was housed in this temple of modernism. I imagined him receiving an aesthetic infusion each day from the building and its dramatic expression. For the next two years I had a personal tutorial with Amheim that feit like an induction into Valhalla. He was carefully attuned to the nuances of what I brought to his office and always generous with his time and guidance. He wrote a letter introducing me to Margaret Naumburg whom he wanted me to meet. When I showed an interest in Hans Prinzhom’s Bildnerei der ~eisteskranke~, which was not yet available in English, he re-read the original German edition (1922) and gave me summaries of chapters in our meetings. Amheim’s interest in the details of patients’ art was illuminating. He responded passionately and curiously to every image and it felt as though we were

Adaptive control for backward quadrupedal walking. IV. Hindlimb kinetics during stance and swing.

1. Hindlimb step-cycle kinetics of forward (FWD) and backward (BWD) walking in adult cats were assessed. The hindlimb was modeled as a linked system of rigid bodies and inverse-dynamics techniques were used to calculate hip, knee, and ankle joint kinetics. For swing, net torque at each joint was divided into three components: gravitational, motion dependent, and a generalized muscle torque. For stance, vertical and horizontal components of the ground-reaction force applied at a point on the paw (center of pressure) were added to the torque calculations. Muscle torque profiles were matched to electromyograms (EMGs) recorded from hindlimb muscles. 2. Torque profiles for BWD swing were the approximate time reversal of those for FWD swing. At each joint, the net torque during swing was small because the mean motion-dependent and muscle torque components counteracted each other. At the hip a flexor muscle torque persisted except for a brief extensor muscle torque late in FWD swing and at the onset of BWD swing. At the knee the muscle torque was relatively negligible except for a peak flexor muscle torque late in FWD swing and early in BWD swing. At the ankle there was a midswing transition from a flexor to an extensor muscle torque during FWD swing and the reverse was true for BWD swing. 3. The vertical ground-reaction force was greater for the forelimbs than the hindlimbs during FWD stance; the reverse was true for BWD stance. Thus the hindlimbs bore a greater percentage (66%) of body weight than the forelimbs during BWD stance, and the forelimbs bore a greater percentage (59%) during FWD stance. For most of FWD stance, the hindlimb exerted a small propulsive ground-reaction force, but for BWD stance the hindlimb first exerted a braking force and then a propulsive force, with the transition occurring after midstance (59% of stance). 4. At the hip the ground-reaction force vector was oriented anteriorly and then posteriorly to the estimated joint center with a midstance transition during FWD stance. The muscle torque and joint power patterns showed similar transitions, changing from extensor and power generation to flexor and power absorption, respectively. For most of BWD stance the ground-reaction force vector was oriented anteriorly to the joint center and was counter-balanced by a large extensor muscle torque; nonetheless, power was absorbed because the hip flexed.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptive control for backward quadrupedal walking. III. Stumbling corrective reactions and cutaneous reflex sensitivity

1. Four cats were trained to walk backward (BWD) and forward (FWD) on a motorized treadmill. Mechanical (taps) or electrical (pulses) stimuli were applied to the dorsal or ventral aspect of the hind paw during swing or stance. Hindlimb kinematic data, obtained by digitizing 16-mm high-speed film, were synchronized with computer-analyzed electromyograms (EMG) recorded from anterior biceps femoris (ABF), vastus lateralis (VL), lateral gastrocnemius (LG), tibialis anterior (TA), and semitendinosus (ST). Responses to taps and pulses, as well as the modulation in cutaneous reflex sensitivity to pulses, were described for both walking directions and stimulus locations. 2. After dorsal taps that obstructed FWD swing, the hindlimb initially drew back away from the obstacle with knee flexion and ST activation, ankle extension with TA suppression and LG activation, and hip extension with ABF facilitation. Next, the limb was raised over the obstacle with resumed TA activity and enhanced knee and ankle flexion, and then compensatory knee and ankle extension positioned the limb for the ensuing stance phase. 3. For ventral taps that obstructed BWD swing, the initial response also tended to draw the limb away from the obstacle with hip and ankle flexion and TA facilitation and reduced knee flexion with weak VL facilitation and suppression of ST activity. Next, ST activity resumed as knee and ankle flexion raised the limb over the obstacle, and then compensatory extension completed the swing phase for BWD walking. Thus the initial kinematic and EMG responses to obstacles were opposite for BWD versus FWD swing, and these responses were consistent with active avoidance of the obstacles. Responses during BWD walking were subtle, however, compared with those for FWD. 4. After nonobstructing taps (ventral FWD, dorsal BWD), ST and TA activation and knee and ankle flexion were coincident, demonstrating that the aforementioned differences in responses to obstructing obstacles were not simply location dependent. Regardless of the direction of walking or the location of stimulation, taps applied during stance had little immediate kinematic effect, but the subsequent swing phase was usually exaggerated, as if the response was programmed to avoid any lingering obstacle. 5. Electrical pulses did not elicit the full-blown responses typically evoked by taps. The sequencing in activation of ST and TA characteristic after laps was absent after pulses, and there were rarely dramatic kinematic responses to pulses like those easily elicited by taps. There were, in fact, few differences in responses to electrical stimulation for BWD versus FWD walking.(ABSTRACT TRUNCATED AT 400 WORDS)

Impact of Financial Incentives on Entrepreneurial Development in Backward Regions—A Case Study of Deoria District of Uttar Pradesh

The dearth of entrepreneurs is one of the reasons for the economic backward ness of a region. To induce people to launch business ventures, most govern ments offer various kinds of incentives. This paper describes the impact of financial incentives on the emergence of new entrepreneurs in a backward region in India.