• Title/Summary/Keyword: random impulses

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Existence and Stability Results on Nonlinear Delay Integro-Differential Equations with Random Impulses

  • Vinodkumar, Arumugam;Gowrisankar, Muthusamy;Mohankumar, Prathiban
    • Kyungpook Mathematical Journal
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    • v.56 no.2
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    • pp.431-450
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    • 2016
  • In this paper, the existence, uniqueness, stability via continuous dependence and Ulam stabilities of nonlinear integro-differential equations with random impulses are studied under sufficient condition. The results are obtained by using Leray-Schauder alternative fixed point theorem and Banach contraction principle.

EXISTENCE UNIQUENESS AND STABILITY OF NONLOCAL NEUTRAL STOCHASTIC DIFFERENTIAL EQUATIONS WITH RANDOM IMPULSES AND POISSON JUMPS

  • CHALISHAJAR, DIMPLEKUMAR;RAMKUMAR, K.;RAVIKUMAR, K.;COX, EOFF
    • Journal of Applied and Pure Mathematics
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    • v.4 no.3_4
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    • pp.107-122
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    • 2022
  • This manuscript aims to investigate the existence, uniqueness, and stability of non-local random impulsive neutral stochastic differential time delay equations (NRINSDEs) with Poisson jumps. First, we prove the existence of mild solutions to this equation using the Banach fixed point theorem. Next, we demonstrate the stability via continuous dependence initial value. Our study extends the work of Wang, and Wu [16] where the time delay is addressed by the prescribed phase space 𝓑 (defined in Section 3). To illustrate the theory, we also provide an example of our methods. Using our results, one could investigate the controllability of random impulsive neutral stochastic differential equations with finite/infinite states. Moreover, one could extend this study to analyze the controllability of fractional-order of NRINSDEs with Poisson jumps as well.

Sexual Problem Behaviors in High School Students (일 지역 고등학생의 성문제 행동)

  • Kim, Hyeon-Ok;Park, Gwang-Sug;Jeon, Mi-Suk
    • The Journal of Korean Academic Society of Nursing Education
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    • v.13 no.2
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    • pp.257-265
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    • 2007
  • Purpose: This study was done to investigate sexual problem behaviors of high school students in one province, North Cholla. Method: The participants in this research were 951 high school students, grades 1, 2 and 3, chosen at random in big cities, small towns and rural areas of North Cholla Province. Result: The routes for sexual knowledge acquisition were through a peer group or an older member(35.8%), internet(29.8%), classes and the teacher at school(18.8%), multimedia(8.4%) and parents (7.2%). The percentages for domains of sexual problem behaviors were masturbation 36.7%, sexual impulse 35.6%, voyeurism 12.6%, sexual violence 9.6%, transvestism 4.1%, prostitution 3.5%, exhibitionism 3.1%, and pregnancy of a female student 0.6%. Sexual problem behaviors experienced by 30% or more of the students were reported as the experience of the desire to embrace, the desire to kiss, the desire to touch a friend's body of the opposite sex, masturbation and the desire to sleep with a friend of the opposite sex. The biggest sexual problem behaviors for the students were sexual impulses toward friends of the opposite sex and masturbation. These experience rates were higher for boys than for girls(p<.05), higher vocationally than academicly(p<.05), and higher in the largest cities than smaller cities and rural area(p<.05). Conclusion: These findings suggest that systematic programs that focus on a problem solution method should be developed for sexual problem behavior prevention.

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Effects of Postural Corrective Exercise Combined with Extracorporeal Shockwave Therapy on Muscle Activity, Neck Function and Pain in Adults with Forward Head Posture

  • Soyeon Kim;Jinghyung Choi;Jihye Jung;Seungwon Lee
    • Physical Therapy Rehabilitation Science
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    • v.13 no.3
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    • pp.343-353
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    • 2024
  • Objective: Long-term imbalances in the muscles around the neck could the functional resting length of the muscles, resulting in a chronic forward head posture. This study aimed to assess the effects of combining posture correction exercises with extracorporeal shockwave therapy on muscle activity, neck function and pain in adults with forward head posture. Design: Pretest-posttest two groups design. Methods: A total of 22 adults, diagnosed with forward head posture, participated in the study. Random assignment allocated 11 participants to the posture correction exercise (PCE) group, while the other 11 were assigned to the posture correction exercise group combined with extracorporeal shockwave therapy (ESWT). In the combined group, ESWT was administered twice a week for four weeks, delivering 1,000 impulses in a radial pattern to the levator scapulae and upper trapezius muscles. The PCE group performed a exercise program for approximately 30 minutes, three times a week, over the same four-week period. The PCE focused on strengthening weakened muscles and stretching of shortened muscles. Results: Both the PCE group and the combined group with ESWT exhibited a significant increase in lower trapezius muscle activity within groups (p<0.05). Moreover, the craniovertebral angle and neck disability index showed significant improvements in both groups (p<0.05). While the pressure pain thresholds tended to increase only in the combined group, the difference was not statistically significant (p>0.05). Conclusions: This suggests that both the PCE program and the combination with ESWT can be effective in enhancing posture and reducing pain in individuals with forward head posture.

An exploration of the relationship between crime/victim characteristics and the victim's criminal damages: Variable selection based on random forest algorithm (범죄 및 피해자 특성과 범죄피해 내용의 관계 탐색: 랜덤포레스트 알고리즘에 기초한 변인선택)

  • Han, Yuhwa;Lee, Wooyeol
    • Korean Journal of Forensic Psychology
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    • v.13 no.2
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    • pp.121-145
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    • 2022
  • The current study applied the random forest algorithm to Korean crime victim survey data collected biennially between 2010 and 2018 to explore the relationship between crime/victim characteristics and the victim's criminal damages. A total of 3,080 cases including gender, age (life cycle stage), type of crime, perpetrator acquisition, repeated victimization, psychological damage (depression, isolation, extreme fear, somatic symptoms, interpersonal problems, moving out to avoid people, suicidal impulses, suicide attempts), and emotional changes after victimization (changes in self-protection confidence, self-esteem, confidence in others, confidence in legal institutions, and respect for Korean legal system/law) were analyzed. Considering the features of data that are difficult to apply traditional statistical techniques, this study implemented random forest algorithms to predict crime and victim characteristics using the victim's criminal damages (psychological damage and emotional change) and selected good predictors using VSURF function in VSURF package for R. As a result of the analysis, it was confirmed that the relationship between the type of crime and depression, extreme fear, somatic symptoms, and interpersonal problems, between perpetrator acquisition and somatic symptoms and interpersonal problems, and between repeated victimization and changes in respect for Korean legal system/law. Gender and life cycle stage (youth/adult/elderly) were found to be related to extreme fear and changes in self-protection confidence, respectively. However, more empirical evidence should be aggregated to explain the results as meaningful. The results of this study suggest that it is necessary to enhance the experts' knowledge and educate them on cases about the relationship between crime/victim characteristics and criminal damage. Strengthening their interview strategy and knowledge about law/rules were also needed to increase the effectiveness of the Korean victim assessment system.