• Title/Summary/Keyword: theoretical analyses

Search Result 838, Processing Time 0.024 seconds

Factor structure of the Buss-Perry aggression questionnaire for a Korean offender population (한국인 범법자들을 대상으로 한 Buss-Perry 공격성 검사지에 대한 요인구조 분석)

  • Soo Jung Lee
    • Korean Journal of Culture and Social Issue
    • /
    • v.11 no.2
    • /
    • pp.47-71
    • /
    • 2005
  • The unexpected increase of violent crimes in Korea urges people to look for more dynamic explanations of criminal behavior other than sociological eugenics such as a struggle between social classes or assimilation to deviant social environment. In this study, criminal behavior is treated as personal matter according to the tradition of psychological theories of crime rather than sociological phenomenon. Furthermore, aggression is supposed to be one of the most basic dispositional characteristics of violent acts. Therefore, this study explored the relationship between aggression measured by BPAQ and criminality evaluated based on seriousness of criminal offenses. On the other hand, the cross-validity of BPAQ was also investigated since prevalence and expressive forms of violence is known to vary across cultures and even within a society. The variance analyses and causal modeling presented that BPAQ had satisfactory level of cross-validity and dispositional aggression measured by BPAQ might have causal effect on criminality of Korean offenders. Additionally, a theoretical internal structure of BPAQ had been confirmed to be reasonable by confirmatory factor analyses.

Predicting Single-hole Blast-induced Fracture Zone Using Finite Element Analysis

  • Jawad Ur Rehman;Duhee Park
    • Journal of the Korean GEO-environmental Society
    • /
    • v.25 no.7
    • /
    • pp.5-19
    • /
    • 2024
  • During the blasting process, a fracture zone is formed in the vicinity of the blast hole. Any damage that extends beyond the excavation boundary line necessitates the implementation of an additional support system to assure safety. Typically, fracture zone radius is estimated from blast hole pressure using theoretical methods due to its simplicity. However, linear charge concentration (kg/m) is used for tunnel blasting. This paper compiles Swedish experimental datasets to estimate the radius of fracture zones based on linear charge concentration. Further numerical analyses are performed in LS-DYNA for coupled single-hole blasting. The Riedel-Hiermaier-Thoma (RHT) model has been selected as the constitutive model for this investigation. The numerical model is validated against small-scale laboratory tests. Parametric studies are conducted to predict fracture zones in granite and sandstone rocks using two kinds of explosives, PETN and AFNO. The analyses evaluate ten types of blast hole sizes, ranging from 17 to 100 mm. The results indicate that granite has a larger fracture zone than sandstone, and the PETN explosive predicts more damage than ANFO. Smaller blast holes exhibit smaller fracture zones in comparison to larger blast holes. Wave propagation is more rapidly attenuated in granite than in sandstone. Subsequently, the predicted fracture zone outcomes are compared with the empirical dataset. Fracture zones of medium blast hole diameter align well with the experimental data set. A predictive equation is derived from the data set, which may be used to evaluate blast design to manage fracture zones beyond the excavation line.

Theoretical Analysis of Embankment Loads Acting on Piles (성토지지말뚝에 작용하는 연직하중의 이론해석)

  • 홍원표;이재호;전성권
    • Journal of the Korean Geotechnical Society
    • /
    • v.16 no.1
    • /
    • pp.131-143
    • /
    • 2000
  • Several theoretical analyses are performed to predict the vertical load on embankment piles with cap beams. The piles are installed in a row in soft ground below the embankment and the cap beams are placed perpendicular to the longitudinal axis of the embankment. Two failure mechanisms such as the soil arching failure and the punching shear failure are investigated according to the failure pattern in embankment on soft ground supported by piles with cap beams. The soil arching can be developed when the space between cap beams is narrow and/or the embankment is high enough. In the investigation of the soil arching failure, the stability in the crown of the arch is compared with that above the cap beams. The factors affecting the load transfer in the embankment fill by soil arching are the space between cap beams, the width of cap beams and the soil parameters of the embankment fill. The portion of the embankment load carried by cap beams decreases with increment of the space between cap beams, while it increases with the embankment height, the width of cap beams, the internal friction angle and cohesion of the embankment fill. Thus, the factors affecting load transfer in embankment should be appropriately decided in order to maximize the effect of embankment load transfer by piles.

  • PDF

Adult-role Burdens and Socio-emotional Development of Children in Poverty (빈곤과 아동의 사회정서적 발달 간의 관계 : 성인역 부담의 역할을 중심으로)

  • Park, Hyun-Sun;Chung, Ick-Joong;Ku, In-Hoe
    • Korean Journal of Social Welfare
    • /
    • v.58 no.2
    • /
    • pp.303-330
    • /
    • 2006
  • The purpose of this study was to investigate the relationships among poverty, family structure and functioning, burdens of adult roles and socio-emotional problems. It was especially focused on the relationship between the burden of adult roles and socioemotional problems among children in poverty. The Structural Equation model was employed for analyses. The Theoretical model was established based on previous researches related to poverty and adult roles (for example, parentification and parentified children). Data came from the first wave of 'Seoul Panel Study of Children; SPSC' and subjects consisted of 1,807 4th grade elementary school students and their parents who were located at K-Gu in Seoul. The survey was carried out from October 25th to November 20th in 2005. The Results of the Structural Equation model were congruent with the theoretical expectations. To find a more appropriate model, three kinds of structural models were hypothesized and analysed. In the most appropriate model which had a good model fit, poverty and family structure impacted on socio-emotional problems directly and indirectly. The relationship between poverty and socio-emotional problems was mediated by family functioning and burdens of adult roles. The same mediation process existed between family structure and socio-emotional problems also. In brief, children in poverty or those who have a single parent are more likely to have impaired family functioning, which is likely to cause higher burdens of adult roles. In turn, those who have higher burdens of adult roles are more likely to have socioemotional problems. In conclusion, various theoretical and practical implications for social work practice focusing on the burdens of adult roles or caretaker roles among children in poverty were discussed.

  • PDF

On the Hybrid Prediction Pyramid Compatible Coding Technique (혼성 예측 피라미드 호환 부호화 기법)

  • 이준서;이상욱
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.21 no.1
    • /
    • pp.33-46
    • /
    • 1996
  • Inthis paper, we investigate the compatible coding technique, which receives much interest ever since the introduction of HDTV. First, attempts have been made to analyze the theoretical transform coding gains for various hierarchical decomposition techniques, namely subband, pyramid and DCT-based decomposition techniques. It is shown that the spatical domain techniques proide higher transform coding gains than the DCT-based coding technique. Secondly, we compare the performance of these spatial domain techniques, in terms of the PSNR versus various rate allocations to each layer. Based on these analyses, it is believed that the pyramid decomposition is more appropriate for the compatible coding. Also in this paper, we propose a hybrid prediction pyramid coding technique, by combining the spatio-temporal prediction in MPEG-2[3] and the adaptive MC(Motion Compensation)[1]. In the proposed coding technigue, we also employ an adaptive DCT coefficient scanning technique to exploit the direction information of the 2nd-layer signal. Through computer simulations, the proposed hybrid prediction with adaptive scanning technuque shows the PSNR improvement, by about 0.46-1.78dB at low 1st-layer rate(about 0.1bpp) over the adaptive MC[1], and by about 0.33-0.63dB at high 1st-layer rate (about 0.32-0.43bpp) over the spatio-temporal prediction[3].

  • PDF

Damage mechanics approach and modeling nonuniform cracking within finite elements for safety evaluation of concrete dams in 3D space

  • Mirzabozorg, H.;Kianoush, R.;Jalalzadeh, B.
    • Structural Engineering and Mechanics
    • /
    • v.33 no.1
    • /
    • pp.31-46
    • /
    • 2009
  • An anisotropic damage mechanics approach is introduced which models the static and dynamic behavior of mass concrete in 3D space. The introduced numerical approach is able to model non-uniform cracking within the cracked element due to cracking in Gaussian points of elements. The validity of the proposed model is considered using available experimental and theoretical results under the static and dynamic loads. No instability and stress locking is observed in the conducted analyses. The Morrow Point dam is analyzed including dam-reservoir interaction effects to consider the nonlinear seismic behavior of the dam. It is found that the resulting crack profiles are in good agreement with those obtained from the smeared crack approach. It is concluded that the proposed model can be used in nonlinear static and dynamic analysis of concrete dams in 3D space and enables engineers to define the damage level of these infrastructures. The performance level of the considered system is used to assess the static and seismic safety using the defined performance based criteria.

Effects of a Simulation based Clinical Reasoning Practice Program on Clinical Competence in Nursing Students (시뮬레이션기반 임상추론 실습교육 프로그램이 간호학생의 간호역량에 미치는 효과)

  • Hur, Hea Kung;Roh, Young Sook
    • Korean Journal of Adult Nursing
    • /
    • v.25 no.5
    • /
    • pp.574-584
    • /
    • 2013
  • Purpose: The purpose of this study was to evaluate the effects of a simulation based clinical reasoning practice program on clinical competence in nursing students. The program was based on the theoretical frameworks of simulation models and experiential learning theory. Methods: The program consisted of eight scenarios which includes three main symptoms (abdominal pain, changes in mental status, dyspnea), for improvement of clinical competencies in nursing students. A nonequivalent control group pretest-posttest design was used for evaluation of the effects of the program. Fifty-two junior nursing students in Y University participated in the experimental group (n=25) or control group (n=27). Critical thinking was measured using a self-administered questionnaire. Clinical judgment and clinical performance were measured by a rater using the Rubric. Descriptive analysis, t-test, Mann-Whitney U, Wilcoxon signed rank test was used for data analyses. Results: Clinical judgment and clinical performance increased in the experimental group, but there were no significant differences in critical thinking. Conclusion: Results indicate that the program developed in this study is a useful strategy to enhance clinical judgment and clinical performance in nursing students. However, the program did not significantly enhance critical thinking disposition, and further study is needed to measure integrated clinical competence including critical thinking skills.

Dynamic Analysis for Evaluation of Speed Control Hump Dimensions (과속방지턱 설치규격 검토를 위한 동역학적 분석)

  • Shim, Jae-Soo;Choi, Hyun-Gyu;Kim, Seong-Min
    • International Journal of Highway Engineering
    • /
    • v.13 no.3
    • /
    • pp.15-20
    • /
    • 2011
  • This study was conducted to evaluate the characteristics of installation dimensions of speed control humps based on the theoretical dynamic analyses. The field surveys of speed control humps were performed first to compare their sizes with those suggested in the installation standard. Then, the displacement response spectra under impact loads were obtained using the single degree of freedom models where the vehicle and human were assumed to combine completely. The analysis results showed that the human perception became larger as the width and height of the humps increased, but the extremely higher uncomfortableness should be avoided. In addition, the ratio between the width and height should be considered when the humps are designed and installed because the ratio governs the vertical acceleration magnitude.

Opportunistic Multiple Relay Selection for Two-Way Relay Networks with Outdated Channel State Information

  • Lou, Sijia;Yang, Longxiang
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.8 no.2
    • /
    • pp.389-405
    • /
    • 2014
  • Outdated Channel State Information (CSI) was proved to have negative effect on performance in two-way relay networks. The diversity order of widely used opportunistic relay selection (ORS) was degraded to unity in networks with outdated CSI. This paper proposed a multiple relay selection scheme for amplify-and-forward (AF) based two-way relay networks (TWRN) with outdated CSI. In this scheme, two sources exchange information through more than one relays. We firstly select N best relays out of all candidate relays with respect to signal-noise ratio (SNR). Then, the ratios of the SNRs on the rest of the candidate relays to that of the Nth highest SNR are tested against a normalized threshold ${\mu}{\in}[0,1]$, and only those relays passing this test are selected in addition to the N best relays. Expressions of outage probability, average bit error rate (BER) and ergodic channel capacity were obtained in closed-form for the proposed scheme. Numerical results and Simulations verified our theoretical analyses, and showed that the proposed scheme had significant gains comparing with conventional ORS.

Estimation Method for Kinematic Constraint of Unknown Object by Active Sensing (미지 물체의 구속상태에 관한 실시간 추정방법)

  • Hwang Chang-Soon
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.29 no.2 s.233
    • /
    • pp.188-200
    • /
    • 2005
  • Control of a multi-fingered robotic hand is usually based on the theoretical analysis for kinematics and dynamics of fingers and of object. However, the implementation of such analyses to robotic hands is difficult because of errors and uncertainties in the real situations. This article presents the control method for estimating the kinematic constraint of an unknown object by active sensing. The experimental system has a two-fingered robotic hand suspended vertically for manipulation in the vertical plane. The fingers with three degrees-of-freedom are driven by wires directly connected to voice-coil motors without reduction gears. The fingers are equipped with three-axis force sensors and with dynamic tactile sensors that detect slippage between the fingertip surfaces and the object. In order to make an accurate estimation for the kinematic constraint of the unknown object, i.e. the constraint direction and the constraint center, four kinds of the active sensing and feedback control algorithm were developed: two position-based algorithms and two force-based algorithms. Furthermore, the compound and effective algorithm was also developed by combining two algorithms. Force sensors are mainly used to adapt errors and uncertainties encountered during the constraint estimation. Several experimental results involving the motion of lifting a finger off an unknown object are presented.