• Title/Summary/Keyword: Stride time

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Approach toward footstep planning considering the walking period: Optimization-based fast footstep planning for humanoid robots

  • Lee, Woong-Ki;Kim, In-Seok;Hong, Young-Dae
    • ETRI Journal
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    • v.40 no.4
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    • pp.471-482
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    • 2018
  • This paper proposes the necessity of a walking period in footstep planning and details situations in which it should be considered. An optimization-based fast footstep planner that takes the walking period into consideration is also presented. This footstep planner comprises three stages. A binary search is first used to determine the walking period. The front stride, side stride, and walking direction are then determined using the modified rapidly-exploring random tree algorithm. Finally, particle swarm optimization (PSO) is performed to ensure feasibility without departing significantly from the results determined in the two stages. The parameters determined in the previous two stages are optimized together through the PSO. Fast footstep planning is essential for coping with dynamic obstacle environments; however, optimization techniques may require a large computation time. The two stages play an important role in limiting the search space in the PSO. This framework enables fast footstep planning without compromising on the benefits of a continuous optimization approach.

Effects of Diagonal Pattern Self-Exercise on Trunk Control, Balance, and Gait Ability in Chronic Stroke Patients

  • Yang, Jaeho;Park, Shinjun;Kim, Soonhee
    • Journal of International Academy of Physical Therapy Research
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    • v.11 no.2
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    • pp.2028-2035
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    • 2020
  • Background: Weakness of the trunk muscles decreases the trunk control ability of stroke patients, which is significantly related to balance and gait. Objectives: To compare the impact of diagonal pattern self-exercise on an unstable surface and a stable surface for trunk rehabilitation on trunk control, balance, and gait ability in stroke patients. Design: Nonequivalent control group design. Methods: Twenty four participants were randomized into the experimental group (diagonal pattern self-exercise while sitting on an unstable surface, n=12) and the control group (diagonal pattern self-exercise while sitting on a stable surface, n=12). All interventions were conducted for 30 minutes, three times a week for four weeks, and the trunk impairment scale (TIS), berg balance scale (BBS), functional gait assessment (FGA), and G-walk were measured. Results: All groups indicated significant increases in all variables (TIS, BBS, FGA, cadence, speed, stride length) after four weeks. The TIS, BBS, FGA, cadence, gait speed, and stride length group-by-time were significantly different between the two groups. Conclusion: We found that, in stroke patients, diagonal pattern self-exercise on an unstable surface is a more effective method for improving trunk control, balance, and gait ability than diagonal pattern self-exercise on a stable surface.

Framework of Security Development Method based on Component (컴포넌트기반 보안개발방법의 프레임워크)

  • Hong, Jin-Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.3
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    • pp.926-930
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    • 2010
  • This paper is about a development framework, which is required to develop of security system is based on component. With applying of SDLC(system development life cycle) of information system, the application of information security products DLC is required at this point of time. In this paper, we review NIST requirement specification of development method, requirement criteria of SDLC in each stage, and major security guidelines of risk assessment. Also we are reviewed major security element of SDLC, and to aid understanding of security framework based on component, present the relationship fo security design and DFD in respect of spoofing for the outside entity based on threat tree STRIDE.

Effects of Action Observation Training Combied with Auditory Cueing on Gait Ability in Patients with Stroke: a Preliminary Pilot Study

  • Kim, Hyeong-Min;Son, Sung-Min;Ko, Yu-Min
    • The Journal of Korean Physical Therapy
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    • v.34 no.3
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    • pp.98-103
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    • 2022
  • Purpose: New therapeutic approaches have emerged to improve gait ability in patients with brain damage, such as action observation learning (AOT), auditory cueing, motor imagery etc. We attempted to investigate the effects of AOT with auditory cueing (AOTAC) on gait function in patients with stroke. Methods: The eighteen stroke patients with a unilateral hemiparesis were randomly divided into three groups; the AOTAC, AOT, and control groups. The AOTAC group (n=8) received training via observing a video that showed normal gait with sound of footsteps as an auditory cue; the AOT group (n=6) receive action observation without auditory stimulation; the control group (n=5) observed the landscape video image. Intervention time of three groups was 30 minutes per day, five times a week, for four weeks. Gait parameters, such as cadence, velocity, stride length, stance phase, and swing phase were collected in all patients before and after each training session. Results: Significant differences were observed among the three groups with respect to the parameters, such as cadence, velocity, stride length, and stance/swing phase. Post-hoc analysis indicated that the AOTAC group had a greater significant change in all of parameters, compared with the AOT and control groups. Conclusion: Our findings suggest that AOTAC may be an effective therapeutic approach to improve gait symmetry and function in patients with stroke. We believe that this effect is attributable to the change of cortical excitability on motor related to cortical areas.

A Study on Security Requirements of Shipboard Combat System based on Threat Modelling (위협 모델링 기반 함정 전투체계 보안 요구사항에 관한 연구)

  • Seong-cheol Yun;Tae-shik Shon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.26 no.3
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    • pp.281-301
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    • 2023
  • The shipboard combat system is a key system for naval combat that supports a command and control process cycle consisting of Detect - Control - Engage in real time to ensure ship viability and conduct combat missions. Modern combat systems were developed on the basis of Open Architecture(OA) to maximize acceptance of latest technology and interoperability between systems, and actively introduced the COTS(Commercial-of-the-shelf). However, as a result of that, vulnerabilities inherent in COTS SW and HW also occurred in the combat system. The importance of combat system cybersecurity is being emphasized but cybersecurity research reflecting the characteristics of the combat system is still lacking in Korea. Therefore, in this paper, we systematically identify combat system threats by applying Data Flow Diagram, Microsoft STRIDE threat modelling methodology. The threats were analyzed using the Attack Tree & Misuse case. Finally we derived the applicable security requirements which can be used at stages of planning and designing combat system and verified security requirements through NIST 800-53 security control items.

Effects of the Education about the Self-application of the Kinesio-Taping for the Adult Women with Chronic Low Back Pain on Pain, Satisfaction and Gait (키네시오 테이핑 자가적용 교육이 만성요통 성인 여성들의 통증, 만족도 및 보행에 미치는 영향)

  • Son, Sungmin;Kwag, Sungwon;Jeon, Byoungjin
    • 재활복지
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    • v.22 no.4
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    • pp.1-22
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    • 2018
  • We aimed to analyze the effects of Kinesio-Taping on pain, satisfaction, and gait, and to provide basic data on the self-application of this method. The participants were 30 adult women with chronic low back pain. Kinesio-Taping was applied for 2 weeks, followed by 4 weeks of self-application education and self-application. The participants' pain levels were analyzed using the visual analog scale, satisfaction was analyzed using the Canadian Occupational Performance Measure, and gait was analyzed in terms of stride length, step length, step width, and gait time using the Walkway MG-1000 gait analyzer. The results of the pain showed the statistically significant decrease steadily (p<0.001) and the results of the satisfaction showed the statistically significant increase steadily (p<0.001) from the application of the Kinesio-Taping. Also, according to the In-Object verification between pre-test, taping application (after 2 weeks) and Self-application (after 4 weeks), the results of the satisfaction showed statistically significant difference (p<0.001). According to the gait analysis, the results of the stride length and step length showed the statistically significant increase steadily (p<0.001) and the results of the step width and gait time showed the statistically significant decrease steadily (p<0.001) from the application of the Kinesio-Taping. Also, according to the In-Object verification between pre-test, taping application (after 2 weeks) and Self-application (after 4 weeks), the results of the step width showed statistically significant difference (p<0.001). Thus, the self-application education about the Kinesio-Taping should be considered to reduce the pain and improve the performance level of the activities of daily life through the improvement of the self-management ability and to induce the active participation in the self-management activities and increase the satisfaction.

A Kinematic Analysis of Gait Patterns between the Normal Men and the Lower Limb Handicapped (정상인과 하지장애자의 보행형태에 대한 운동학적 분석)

  • Kim, Moo-Young
    • Korean Journal of Applied Biomechanics
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    • v.13 no.3
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    • pp.163-180
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    • 2003
  • This paper aims at collecting the guantitative data of kenematic variables by analysing the gait patterns of the normal adult men and the handicapped. The gait motions were taped with 4 video cameras, the cinematographic analyses were performed by the DLT technique of three dimensional image treatment. The following results were obtained in the analysis of the variables: 1. The ratio of stance time and swing time did not show any significant difference in the groups of the normal men and the handicapped when both foot of the former and the right feet of the latter were compared. The stride peeriod time of these two groups were 1.12 and 1.11 second, respectively. 2. In the handicapped group, the step width was wider, the step length and stride length were shorter, and especially, the step length of the right foot was shorter, 3. The small vertical displacement of left toes of the handicapped group showed that the heal contact and the left midstance are almost simultaneous. 4. The two groups have almost the same horizontal displacement of the center of gravity and the same vertical rate of extension. In view of the velocity of the center of gravity the normal adults showed the constant speed of movement. However, the handicapped adults were reduced from the right midstance to the right toe-off. 5. The handicapped showed prominently low angle on the left toe-off in the ankle joint angle, they also had the tendency to walk in the patterns of extended knee in the knee joint angle. Both the handicapped and the normal had the hyperextension on the toe-off in the hip joint angle. In the back and front angle of body, both showed the slightly back-sided walking positions. 6. Both groups had the abduction of both feet in foot placement angle, but the handicapped did not show serious abduction of left midstance.

The Kinematic Analysis on the Instep Shooting Motion of Female High School Soccer Players According to the Angles of Approach (접근각도에 따른 여자고등학교 축구선수의 인스텝 슈팅 동작에 관한 운동학적 분석)

  • Cho, Kyu-Kwon;Kim, You-Sin;Choi, Gil-Soon
    • Korean Journal of Applied Biomechanics
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    • v.16 no.2
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    • pp.153-163
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    • 2006
  • The purpose of this research was to analyze kinematic variables that appear during the instep shooting motion of female high school soccer players according to the angle of approach to find effective shooting motions. For this experiment, 5 female high school soccer players from the K city were participated in this study as the subject group, and as a through comparison and analysis of the resulting numbers of the variables, we came to the following conclusions. 1) Stride length and stride length/lower extremity length increased as the angle of approach increased. 2) As for C.O.G movement displacement, it was highest at an approach angle of $90^{\circ}$ during Right Foot Contact, at $135^{\circ}$ during Left Foot Contact, at $0^{\circ}$ during Rigth Toe Top, at $45^{\circ}$ during Impact, and at $0^{\circ}$ during Follow through. 3) The time required for each phase was longest at APP and shortest at BSP. The time required increased a little as the angle of approach increased, and the total time required also increased as the angle of approach increased. 4) The angle of the ankle joint was largest at an approach angle of $45^{\circ}$ for all events except Right Foot Contact. 5) The angle of the knee joint was largest at an approach angle of $135^{\circ}$ during Right Foot Contact, at $0^{\circ}$ during Left Foot Contact, at $45^{\circ}$ during Right Toe Top, at $135^{\circ}$ during Impact, and at $90^{\circ}$ during Follow through. 6) The angle of the hip joint was largest at an approach angle of $90^{\circ}$ during Right Foot Contact, at$0^{\circ}$ during Left Foot Contact, at $0^{\circ}$ during Right Toe Top, at $90^{\circ}$ during Impact, and at $0^{\circ}$ during Follow through.

The Effect of Gait Exercise Using a Mirror on Gait for Normal Adult in Virtual Reality Environment: Gait Characteristics Analysis (가상현실환경에서 정상성인의 거울보행이 보행특성에 미치는 영향)

  • Lee, Jae-Ho
    • Journal of The Korean Society of Integrative Medicine
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    • v.10 no.3
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    • pp.233-246
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    • 2022
  • Purpose : The study aims to determine the effects of virtual and non-virtual realities in a normal person's mirror walk on gait characteristics. Methods : Twenty male adults (Age: 27.8 ± 5.8 years) participated in the study. Reflection markers were attached to the subjects for motion analysis, and they walked in virtual reality environments with mirrors by wearing goggles that showed them the virtual environments. After walking in virtual environments, the subjects walked in non-virtual environments with mirrors a certain distance away after taking a 5 min break. To prevent the order effect caused by the experiential difference of gait order, the subjects were randomly classified into groups of 10 and the order was differentiated. During each walk, an infrared camera was used to detect motion and the marker positions were saved in real time. Results : Comparison between the virtual and non-virtual reality mirror walks showed that the movable range of the leg joints (ankle, knee, and hip joints), body joints (sacroiliac and atlantoaxial joints), and arm joints (shoulder and wrist joints) significantly differed. Temporal characteristics showed that compared to non-virtual gaits, the virtual gaits were slower and the cycle time and double limb support time of virtual gaits were longer. Furthermore, spacial characteristics showed that compared to non-virtual gaits, virtual gaits had shorter steps and stride lengths and longer stride width and horizontally longer center of movement. Conclusion : The reduction in the joint movement in virtual reality compared to that in non-virtual reality is due to adverse effects on balance and efficiency during walking. Moreover, the spatiotemporal characteristics change based on the gait mechanisms for balance, exhibiting that virtual walks are more demanding than non-virtual walks. However, note that the subject group is a normal group with no abnormalities in gait and balance and it is unclear whether the decrease in performance is due to the environment or fear. Therefore, the effects of the subject group's improvement and fear on the results need to be analyzed in future studies.

Analysis of the Body Segment Kinematics by Lap Time during Men's 5,000m Racing (남자 5000M 경주 시 순위에 따른 랩 타임별 운동학적 변인 분석)

  • Chung, Nam-Ju
    • Korean Journal of Applied Biomechanics
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    • v.15 no.2
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    • pp.197-207
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    • 2005
  • The purpose of this study was to investigate the body segment kinematics by lap time during men's 5,000m racing. The subjects in this study were 4 male athletics who take part in the competition. The two dimension motion analysis with DLT(direct linear transformation) method was executed using digital video cameras. The following conclusion was that : It was shown that top ranking in a competition is continuous race pattern and the last Lap time is the most fast. It was shown that top ranking in a competition is continuos the stride length and it was the largest in the last Lap time. It was shown that according to the passing Lap time trunk frontal angle was decreasing and shoulder angle was continuous.