• Title/Summary/Keyword: Physical impact

Search Result 2,042, Processing Time 0.031 seconds

Development of an Impact Force Measurement Device with an Attached Strain Gauge (스트레인게이지가 부착된 충격력 측정 장비 개발)

  • Jeong, Ik-Su
    • Korean Journal of Applied Biomechanics
    • /
    • v.22 no.2
    • /
    • pp.243-251
    • /
    • 2012
  • The purpose of this study was to develop an impact force measurement device in order to facilitate the acquisition of quantitative data for the analysis of various sporting events. The device was designed to include cylindrical aluminum supports of 220 mm diameter, which allows mounting and dismounting of the device on walls and frames. In addition, a hard sponge for impact absorption, as well as 4 springs, were attached to the plate. Both were attached to prevent psychological variables and injuries. When a subject applies force on the device, accurate data about the maximum repulsive force is acquired in real time, with a lag of only 0.001 s. The device was calibrated in four steps: (1) increase, (2) increase, (3) increase-decrease, and (4) increase-decrease. The maximum relative expanded uncertainty was 0.166%, indicating that the impact force measurement was sufficiently reliable. The proposed device can be applied to various sporting situations and is expected to be useful for studying kinetics.

A study on the evaluation technique of floor impact noises using Cross-matching and AAS (Cross-matching과 AAS에 의한 바닥충격음 평가기술에 관한 연구)

  • Jeong, Young;Kim, Jeong-Mi;Jeon, Jin-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2000.06a
    • /
    • pp.172-176
    • /
    • 2000
  • A series of preliminary experiments were carried out to quantify the annoyance are noisiness caused by floor impact noise. From the results of the experiments. the heavy impact source was found to be felt louder and noisier than the light impact source. Measurements of noise were also conducted by a diagnostic system based on the model(the model consists of the autocorrelators and the cross-correlation for signals arriving at two ear entrants) of the human auditory-brain system. Physical factors in the model were calculated by use of the ACF(autocorrelation function) and IACF(interaural cross correlation function) of binaural signals. From the ACF/IACF analysis, it was found that perceived loudness of floor impact noise could be represented by the factors of the ACF/IACF model.

  • PDF

Ballistic behavior of steel sheet subjected to impact and perforation

  • Jankowiak, Tomasz;Rusinek, Alexis;Kpenyigba, K.M.;Pesci, Raphael
    • Steel and Composite Structures
    • /
    • v.16 no.6
    • /
    • pp.595-609
    • /
    • 2014
  • The paper is reporting some comparisons between experimental and numerical results in terms of failure mode, failure time and ballistic properties of mild steel sheet. Several projectile shapes have been considered to take into account the stress triaxiality effect on the failure mode during impact, penetration and perforation. The initial and residual velocities as well as the failure time have been measured during the tests to estimate more physical quantities. It has to be noticed that the failure time was defined using a High Speed Camera (HSC). Thanks to it, the impact forces (average and maximum level), were analyzed using numerical simulations together with an analytical description coupled to experimental observations. The key point of the model is the consideration of a shape function to define the pulse loading during perforation.

The Analysis of Impact at the Fin of High Speed Water-Entry Body (고속입수체의 제어판 충격해석)

  • Nah, Young-In;Lee, Sim-Yong
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.13 no.6
    • /
    • pp.1026-1033
    • /
    • 2010
  • The analysis of water-entry impact forces acting on the fin shaft of high speed water-entry body is described. During the entry of high speed body into water, the physical phenomenon and flow properties are analyzed. A proper analysis model is established and the method to estimate the flow force which causes impact torque at the fin shaft is described. It is assumed that the fin shaft is damaged by the force which is induced by contacting with cavity wall. The pressure distribution of fin and the maximum torque are estimated and compared with breaking force. Conclusively, it is hard to resist water-entry impact force in terms of the reinforcement of fin shaft. Additionally safe equipment is essentially required.

A Study on Landscape Impact Assessment Techniques in District Unit Plan (지구단위계획에서 사용된 경관영향평가 기법에 관한 연구)

  • Bong, Jong-Jin;Jung, Young-Duk;Lee, Bong-Su;Cho, Yong-Joon
    • Proceeding of Spring/Autumn Annual Conference of KHA
    • /
    • 2005.11a
    • /
    • pp.219-222
    • /
    • 2005
  • District unit plan was arranged for rational induction and regulation of development due to increase of demand for comfortable environment and change of recognition of urban view. This study analyzes cases of district unit plan since 2003 and draws the following conclusions to provide basic material necessary for landscape impact assessment and analysis of actual conditions. It used regulation of design factors and analysis of physical index in making view plan and focuses on characteristics of visual perception in predicting impact through simulation. Future landscape impact assessment must establish a variety of indices and application of various techniques.

  • PDF

Effects of Informatization Mind on Information Development Efforts and Academic Achievement of University Students Major in Sports

  • Kim, Seyun
    • International Journal of Internet, Broadcasting and Communication
    • /
    • v.13 no.2
    • /
    • pp.166-172
    • /
    • 2021
  • The purpose of this study is to identify the impact of informatization minds of college students majoring in sports on information development efforts and academic achievement. Accordingly, a survey was conducted on 200 college students majoring in physical education at D University, and 197 students were selected as the final effective samples. Data processing was conducted using SPSS 23 for frequency analysis, reliability analysis, correlation analysis, and regression analysis. The results are as follows: First, recognition of the necessity of informatization education, a subfactor of the informatization mind, has a positive impact on informatino development efforts. Second, recognition of the necessity of informatization education, understanding and utilization of informatization concepts among sub-factors of informatization minds have a positive impact on the major learning achievement. Third, all the conversational factors in the informatization mind have a positive impact on study problem resolution. Fourth, information development efforts have a positive impact on the major learning achievement and the study problem resolution. Therefore, efforts are needed to increase the information mindset of college students major in sports.

Analysis and Improvement of Soil Physical and Chemical Properties for Transplantation of Damaged Trees (훼손 수목의 이식을 위한 토양의 물리·화학적 특성 분석과 개선 방안)

  • Hyesu, Kim;Jungho, Kim;Yoonjung, Moon;Seonmi, Lee
    • Journal of Environmental Impact Assessment
    • /
    • v.31 no.6
    • /
    • pp.423-437
    • /
    • 2022
  • Parts of damaged trees are being transplanted in accordance with the Environmental Impact Assessment Manual. Problems such as death or poor growth are constantly being addressed in the process of transplanting trees from the forest they originally inhabited to temporary and final transplant sites. The purpose of this study is to analyze the differences in soil properties in the surrounding forest, the temporary transplant site, and the construction site and to suggest methods for improving the soil to make it suitable for the growth of transplanted trees. For 10 development projects, 2 soil samples were sampled from the surrounding forest, temporary transplant site, and construction site. A total of 60 soil samples were analyzed for physical and chemical properties. Among the physical properties such as coefficient of permeability, available moisture, and hardness, and chemical properties such as acidity, organic matter content, total nitrogen, and available P showed significant differences among groups. The soil of the construction site is harder than the surrounding forest because of construction equipments, the coefficient of permeability is higherthan the surrounding forest because of high sand content, and the available moisture was low. It does not retain the moisture necessary for plants in the soil and drains immediately. It is necessary to implement tillage to improve the physical properties and structure of the soil. In addition, it is necessary to cover the surface with wood chips or fallen leaves after adding mature organic matter to improve the physical and chemical properties of the soil together.

A Study on the Inter-Relationships between Physical Form and Density of Multi-Family Housing (공동주택의 물리적 형태와 밀도의 상관성 연구)

  • Choi Moo-Hyun;Choi Joo-Young;Yang Jung-Pil
    • Journal of the Korean housing association
    • /
    • v.17 no.1
    • /
    • pp.67-75
    • /
    • 2006
  • Multi-family housings caused several problems related to physical form such as isolation of housing estate, inhumanity of the exterior space, and mismatch with the urban structure. To handle these problems, the purpose of this study is to analyse density elements which have a direct impact on physical forms, thereby understand the characteristics of physical form and also identify a meaning of inter-relationships between them. Therefore both formal constituents and density elements are reformed into respective analyzing indices. From the analysis, physical form and the spatial layout of buildings were more uniform in large-scale housing estates than in medium or small housing estates. However, small-scale housing estates showed various form and the spatial layout of buildings in order to increase the building density.

Conflict Resolution Acts of Rural Spouses (도시근교 농촌부부의 갈등표출행동에 관한 연구)

  • 이정화;최은숙;한경혜
    • Korean Journal of Rural Living Science
    • /
    • v.6 no.1
    • /
    • pp.41-54
    • /
    • 1995
  • This study is to investigate the marital conflict resolution acts (CRA) of rural spouses and to explore the relationship between the CRA and several important factors : socio-demographic, marital relation and drinking pattern factors. Participants in this study are 150 rural women who are married and live with their husband. A modification of the Conflict Tactics Scale is used to measure the CRA of four levels, reasoning, verbal aggression, minor physical violence, and heavy physical violence. The major findings of this study are as follows. First the frequencies of each type of the CRA-reasoning, verbal aggression, minor physical violence and heavy physical violence-are 12.1%, 57.9%, 17.1% and 12.9% respectively. Therefore, the verbal aggression is the most prevalent type of the CRA Second, the result from multiple regression shows that the conflict from husband's whoring, husband's drinking capacity and family type have a meaningful impact on husband's physical violence.

  • PDF

Inter-Rater Reliability of Chedoke-McMaster Stroke Assessment for Stroke Patients (뇌졸중환자 평가를 위한 Chedoke-McMaster Stroke Assessment의 측정자간 신뢰도)

  • Won, Jong-Hyuk;Kim, Yong-Wook
    • Physical Therapy Korea
    • /
    • v.4 no.3
    • /
    • pp.45-60
    • /
    • 1997
  • This study was performed to determine the inter-rater reliability of the Chedoke-McMaster Stroke Assessment translated in Korean. This measures the physical impairments and disabilities that impact on the lives of individuals with stroke. The purposes of this measure were 1) to stage motor recovery to classify individuals in terms of clinical characteristics, 2) to predict rehabilitation outcomes, and 3) to measure clinically important change in physical function. Twenty-two subjects from physical therapy unit were assessed by two physical therapists. The ratings were compared by Spearman's rank correlation The correlation between two raters ranged from 0.85 to 0.98. Inter-rater reliability coefficient for total scores ranged from 0.95 to 0.97. This study confirms that the Chedoke-McMaster Stroke Assessment yields reliable results.

  • PDF