Impulsive Problems Research Articles

Does mindfulness enhance stock trading performance?: the moderating and mediating effects of impulse control difficulties

This research investigates the contribution of mindfulness on performance of stock traders. The authors focus on the role of mindfulness in helping individuals lower impulsive behaviours when they trade stocks. Survey data were collected from 120 independent traders and 73 professional traders in Thailand (total N = 193). The analysis from partial least squares regression found that impulse control difficulties mediated the link between mindfulness and stock trading performance. This suggested that individuals with higher mindfulness measure tended to experience lower impulse control difficulties problem, and subsequently exhibited better stock trading performance. However, the analysis of the moderating effect revealed that the positive contribution of mindfulness on stock trading performance is only present for those with high impulse control difficulties. Surprisingly, mindfulness appeared to lower trading performance of traders who did not have impulse control difficulties.

Impulsive synchronization of Lü chaotic systems via the hybrid controller

Abstract In this paper, the impulsive synchronization problem of Lu chaotic systems is investigated by using a novel hybrid controller. The proposed hybrid controller is composed of a single controller and impulsive controller. Using the impulsive theory and the novel hybrid controller, some sufficient conditions are derived for the synchronization of Lu chaotic systems. Numerical simulation example is provided to verify the effectiveness of the proposed approach. The simulation results show that the proposed control scheme has a fast convergence rate compared with the conventional single controller method and impulsive controller method.

Characteristics and correlates of stealing in college students.

Stealing is a fairly common behaviour among young adults. Understanding the potential associations and characteristics of individuals who steal may help educational institutions, health services and young people themselves resolve difficulties before the behaviour impacts on their academic performance and health. We aim to test the hypothesis that desires to steal among students would be associated with worse academic achievements and higher rates of mood and impulse control disorders. One thousand eight hundred and five students completed the College Student Computer User Survey online and were included in this analysis at a large Midwestern United States University. Responders were grouped according to self-reported stealing urges and behaviours and were compared on measures of psychosocial function, mental health disorders and impulsivity. Urges to steal were associated with worse depressive symptoms, higher levels of perceived stress and a number of psychiatric disorders including bipolar disorder and multiple disorders of impulse control (kleptomania, compulsive sexual behaviour, skin picking, trichotillomania and compulsive buying). CONCLUSIONS AND IMPLICATIONS FOR PRACTICE AND/OR FUTURE RESEARCH: These following data indicate that stealing for many college students may be considered within a spectrum of impulsive behaviours. • Illegal behaviours among students point to mental health difficulties among them. • Our findings may provide clinicians, researchers and health professionals with a clearer picture of a range of impulsive behaviours among college students and promote treatment for this group. • Our findings could also inform preventative approaches to impulsive problems in young adults.

On boundary value problems for impulsive fractional differential equations

In the present paper, we deal with the existence of solutions for the following impulsive fractional boundary value problem:{tDTα(0cDtαu(t))+a(t)u(t)=f(t,u(t)),t≠tj,a.e.t∈[0,T],Δ(tDTα−1(0cDtαu))(tj)=Ij(u(tj)),j=1,2,…,n,u(0)=u(T)=0,where α ∈ (1/2, 1], 0=t0<t1<t2<⋯<tn<tn+1=T,f:[0,T]×R→R and Ij:R→R,j=1,…,n, are continuous functions, a ∈ C([0, T]) andΔ(tDTα−1(0cDtαu))(tj)=tDTα−1(0cDtαu)(tj+)−tDTα−1(0cDtαu)(tj−),tDTα−1(0cDtαu)(tj+)=limt→tj+(tDTα−1(0cDtαu)(t)),tDTα−1(0cDtαu)(tj−)=limt→tj−(tDTα−1(0cDtαu)(t)).By using critical point theory and variational methods, we give some new criteria to guarantee that the above-mentioned impulsive problems have at least one solution or infinitely many solutions. Some examples are also provided.

Variational approach to impulsive differential system

In this work, we consider a nonlinear Dirichlet problem with impulses and obtain the existence of solutions to an impulsive problem by means of variational methods.

Viable periodic solutions in state-dependent impulsive problems

Periodic solutions of state-dependent impulsive ODEs in a prescribed set of constraints are examined. The so-called impulsive index is introduced, as a topological tool, and its properties are studied. Some sufficient conditions for its homotopy property are discussed in detail. In a construction of the impulsive index the fixed point index on ANRs is applied to an induced discrete semidynamical system on a barrier where jumps occur. Several illustrative examples are added.

The effects of a Self-Alert Training (SAT) program in adults with ADHD.

Attention-Deficit/Hyperactivity Disorder (ADHD), a neuropsychiatric condition characterized by attention and impulsivity problems, is one of the most common behavioral disorders. The first line of treatment for ADHD is psychostimulant medication, but this has limited effectiveness, particularly in adults, and is often associated with adverse side-effects. Thus, it is imperative that new non-pharmaceutical approaches to treatment are developed. This study aims to evaluate the impact of a non-pharmacological Self-Alert Training (SAT) intervention on ADHD symptom prevalence, psychological and cognitive functioning, and on everyday functional impairment in adults with ADHD. Fifty-one adult participants with a current diagnosis of ADHD were randomized to either SAT or a Control Training (CT) program. They were assessed at baseline, immediately following the 5-week training period, and after 3-months using ADHD symptoms scales, as well as a series of neuropsychological tests and psychological questionnaires. Subjective ratings of everyday life attention and memory problems were also collected. The SAT group showed significant improvements in ADHD inattentive and impulsive symptoms, depressive symptoms and in self-efficacy ratings compared to the CT group at both post-training and at the 3-month assessment. Pre-post improvements in SAT participants on untrained cognitive tasks measuring selective attention and executive functions were also observed. Finally, the SAT group reported improved subjective ratings of everyday life attention at both assessment points. This pattern of results suggests that SAT may be beneficial in treating ADHD symptoms as well as psychological and cognitive impairments in adult ADHD. A large-scale randomized controlled trial (RCT) is needed.

Does Early Exposure to Stimulants Lead to Substance Use Disorders Later on?

Attention deficit/hyperactivity disorder (ADHD) denotes childhood problems of hyperactivity, inattention, and impulsivity, leading to impairments in daily functioning, scholastic performance, and relationships with peers. Although the rationale for stimulant medication is to reduce the morbidity associated with having ADHD, critics have argued that methylphenidate and other prescribed stimulant drugs (PSDs) are overly prescribed and inherently dangerous. Researchers have also raised concerns that PSDs might prime the central nervous system, thus rendering individuals more susceptible to substance use disorders (SUDs) later in life. There is also a strong comorbidity between ADHD and SUDs in adulthood. If many adults with SUDs were prescribed stimulants for ADHD as children or during adolescence, this could suggest that taking these drugs during these critical developmental periods increase the risks for SUDs later on. Research articles (i.e., both animal and human data) were reviewed to ascertain if any associations exist between PSDs and brain and behavioral changes. Review articles, meta-analyses, clinical trials, and clinical data were examined to assess associations between PSDs during childhood and adolescence and the development of SUDs in adolescence and adulthood. Contentious evidence does suggest that PSDs are not likely responsible for substance use and SUDs in adolescence, although it remains equivocal if PSDs offer any protection against substance use and abuse in adolescence. Although PSDs do reduce symptoms of ADHD that may interfere with learning in childhood, the evidence raises the possibility that these drugs might be responsible for substance use and SUDS in some adults.

Remain Aggressive Behavior in Children with Temporal Lobe Epilepsy after Surgery

Behavioral problems have a high rate in patients with temporal lobe epilepsy but there have been few detailed reports about pediatric patients. We report two children with temporal lobe epilepsy who manifest behavior abnormality remaining after surgery. One child developed complex partial seizures at 10 years and 3 months of age caused by a left temporal ganglioglioma and manifested behavioral problems of lability, aggression, impulsivity and disinhibition. Seizures were relieved after temporal lobe resection at 10 years and 8 months of age but behavioral symptoms had been remained. The second child developed epilepsy at 3 years of age. He manifested similar behavioral problems at 7 years old. Seizures were relieved after temporal lobe resection at 13 years old but behavioral symptoms had been remained. Their courses suggested that aggressive behavior might be associated with not only temporal lesion but also other lesions such as frontal lobe or neural circuitry between both lobes. It is important to inform families of patients that behavioral disorders may not improve after epileptic surgery.

Model Predictive Control for Spacecraft Rendezvous in Elliptical Orbits with On/Off Thrusters

In previous works, the authors have developed a trajectory planning algorithm for spacecraft rendezvous which computed optimal Pulse-Width Modulated (PWM) control signals, for circular and eccentric Keplerian orbits. The algorithm is initialized by solving the impulsive problem first and then, using explicit linearization and linear programming, the solution is refined until a (possibly local) optimal value is reached. However, trajectory planning cannot take into account orbital perturbations, disturbances or model errors. To overcome these issues, in this paper we develop a Model Predictive Control (MPC) algorithm based on the open-loop PWM planner and test it for elliptical target orbits with arbitrary eccentricity (using the linear time-varying Tschauner-Hempel model). The MPC is initialized by first solving the open-loop problem with the PWM trajectory planning algorithm. After that, at each time step, our MPC saves time recomputing the trajectory by applying the iterative linearization scheme of the trajectory planning algorithm to the solution obtained in the previous time step. The efficacy of the method is shown in a simulation study where it is compared to MPC computed used an impulsive-only approach.

Distributed impulsive group consensus in second-order multi-agent systems under directed topology

This paper investigates the impulsive group consensus problems of second-order multi-agent systems under directed network topology with acyclic partition. Two distributed impulsive sampled-data protocols are presented to realise group consensus for both cases with leaders and leaderless, and then some simple yet generic criteria on convergence for such algorithms are established. It is shown that, for the case with leaderless, a feature of the present protocols is to give an explicit expression of group consensus states in terms of the initial values of the agents, which allows us to develop a simple approach yielding the desired group or cluster consensus. While for the case of virtual leaders, a pinning-like tracking technique is effectively designed to regulate all the agents access to the virtual leaders respectively for the purpose of practical control strategy. Finally, simulation results are presented to illustrate the effectiveness of the theoretical analysis.

Fixed point problem associated with state-dependent impulsive boundary value problems

The paper investigates a fixed point problem in the space which is connected to boundary value problems with state-dependent impulses of the form , a.e. , , . Here, the impulse instants are determined as solutions of the equations , . We assume that , , the vector function f satisfies the Carathéodory conditions on , the impulse functions , , are continuous on , and the barrier functions , , are continuous on . The operator ℓ is an arbitrary linear and bounded operator on the space of left-continuous regulated on vector valued functions and is represented by the Kurzweil-Stieltjes integral. Provided the data functions f and are bounded, transversality conditions which guarantee that this fixed point problem is solvable are presented. As a result it is possible to realize the construction of a solution of the above impulsive problem. MSC: 34B37, 34B10, 34B15.

Multiple solutions to boundary value problem for impulsive fractional differential equations

Abstract We study the multiplicity of solutions for fractional differential equations subject to boundary value conditions and impulses. After introducing the notions of classical and weak solutions, we prove the existence of at least three solutions to the impulsive problem considered.

Optimal dividend, capital injection and reinsurance strategies with variance premium principle

This paper considers the combined optimal dividend, capital injection and reinsurance strategies for an insurance company. The proportion reinsurance is taken as a risk control, the variance principle is adopted by the insurer and the reinsurer with different parameter respectively. Furthermore, the insurer can control its surplus by paying dividends and injecting capitals, which incur both proportional and fixed costs. The value of the company is defined as the difference between the expected discounted dividends and the expected discounted capital injections until the time of bankruptcy. To maximize the value of the company, by solving the impulse problem, we obtain explicit solutions for value function and optimal strategy.

Existence of mild solutions for the impulsive semilinear nonlocal problem with random effects

In this paper, we study the existence of impulsive semilinear nonlocal problems with random effects. Random perturbations are taken into consideration in abstract spaces. By applying the measure of noncompactness and a random fixed point theorem with stochastic domain, we get some existence results which improve and generalize many known results. Some weaker assumptions are established. Besides, we do not claim the semigroup to be compact.

The Relationship Between Problematic Internet Entertainment Use and Problem Solving Skills Among University Students

The current study aimed to investigate the relationship between Internet addiction and problem solving skills of university students. The study also examined the psychometric properties of the Turkish version of Problematic Internet Entertainment Use Scale for Adolescents, which centers on major Internet entertainments such as online video games and social networking sites, specifically with regard to normative, reliability, and validity information. Problem Solving Inventory was utilized in order to measure the problem solving skills of students. Both instruments were administered to 371 students aged 17 to 36 years from different departments in Marmara University and Istanbul Technical University (Istanbul, Turkey). This study showed that the Turkish version of the Problematic Internet Entertainment Use Scale for Adolescents was a reliable and valid instrument for measurement of maladaptive patterns in the use of online entertainments such as OVG and SNS. The results revealed that there is a close relationship between problematic internet entertainment use and Avoidant (r = 443; p < .01) and Impulsive problem solving styles (r = .402; p < .01) among university students.

Periodic BVPs for fractional order impulsive evolution equations

In this paper, we study periodic BVPs for fractional order impulsive evolution equations. The existence and boundedness of piecewise continuous mild solutions and design parameter drift for periodic motion of linear problems are presented. Furthermore, existence results of piecewise continuous mild solutions for semilinear impulsive periodic problems are showed. Finally, an example is given to illustrate the results.

Measure differential inclusions - between continuous and discrete

The paper is devoted to the study of the measure-driven differential inclusions , for arbitrary finite Borel measure μ. This type of results allows one to treat in a similar manner differential and difference inclusions, as well as impulsive problems and therefore to study the evolution of hybrid systems with very complex (including Zeno) behavior. Our method is based on viewing the Borel measures as Lebesgue-Stieltjes measures. We thus obtain, under very general assumptions, the existence of regulated or bounded variation solutions of the considered problem and we indicate some advantages of our approach. MSC:49N25, 34A60, 93C30, 49J53, 37N35, 34A37.

Impulsive fractional boundary-value problems with fractional integral jump conditions

Abstract In this paper we establish the existence and uniqueness of solutions for impulsive fractional boundary-value problems with fractional integral jump conditions. By using a variety of fixed-point theorems, some new existence and uniqueness results are obtained. Illustrative examples of our results are also presented. MSC:34A08, 34B37, 34B15, 34B10.

Stochastic Maximum Principle for Partial Information Optimal Control Problem of Forward-Backward Systems Involving Classical and Impulse Controls

We study the partial information classical and impulse controls problem of forward-backward systems driven by Lévy processes, where the control variable consists of two components: the classical stochastic control and the impulse control; the information available to the controller is possibly less than the full information, that is, partial information. We derive a maximum principle to give the sufficient and necessary optimality conditions for the local critical points of the classical and impulse controls problem. As an application, we apply the maximum principle to a portfolio optimization problem with piecewise consumption processes and give its explicit solutions.