• Title/Summary/Keyword: open-chain

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Dynamic Equations of Robots and Sensitivity Analysis (로봇 운동방정식과 감도해석)

  • Song, Sung-Jae;Lee, Jang-Moo
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.6
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    • pp.105-111
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    • 1995
  • The inverse dynamic equations for 5 link robot including a closed chain have been derived. The closed chain is virtually cut open, and the kinematics and dynamics of the virtual open chain robot are analyzed. The constraints are applied to the virtually cut joints by the Jacobian matrix which represents the configuration of the closed chain. The topology of tree structrued open chain robot is described by a FATHER array. The FATHER array of a link indicates the link tha tis connected in the direction of base link. Based on the inverse dynamic equations, the torque sensitivity models of the 5 link robot have been developed. The sensitivity models characterize the sensitivity of the driving torque with respect to the link parameters. All the procedures are illustrated through the 2 link robot.

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Software Supply Chain Management and SBOM Trends (SW공급망 관리 및 SBOM 동향)

  • W.O. Ryoo;S.M. Park;S.Y. Lee
    • Electronics and Telecommunications Trends
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    • v.38 no.4
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    • pp.81-94
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    • 2023
  • The increased adoption of open source security management in supply chains is gaining worldwide attention. In particular, as security and threatening situations, such as solar winds, Kaseya ransomware, and Log4j vulnerability, are becoming more common in supply chains using software (SW)-defined networks, SW bills of materials (SBOMs) for SW products should be prepared to protect major countries like the United States. An SBOM provides SW component information and is expected to become required for SW supply chain management. We focus on SW supply chain management policies and SBOM trends in major countries and private organizations worldwide for safe SW use and determine the current status of Korea and ETRI's open source SW supply chain management trends.

Effects of Closed and Open Kinetic Chain Exercises on Knee Extensor Strength and Balance in Patients with Early Stroke (닫힌사슬운동과 열린사슬운동이 초기 뇌졸중환자의 무릎신전근 근력과 균형에 미치는 영향)

  • Kwon, O-Kook;Shin, Won-Seob
    • Journal of the Korean Society of Physical Medicine
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    • v.9 no.2
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    • pp.223-231
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    • 2014
  • PURPOSE: The aim of this study was to investigate the effect of closed and open kinetic exercises on knee extensor strength and balance in patients with early stroke. METHODS: Thirty patients with early stroke participated in the study. Participants were randomly assigned to three groups: an open kinetic chain (OKC) exercise group (n=10), a closed kinetic chain (CKC) exercise group (n=10), and a control group (n=10). All participants received conventional physical therapy for 30 minutes. In addition, the two experimental groups (OKC and CKC) participated in a 30-minute knee strengthening training program. Training for the experimental groups was carried out three times a week for four weeks. Outcomes such as knee extensor strength and balance ability (Tetrax, Functional Reaching Test, Timed Up and Go Test) were measured before and after training. RESULTS: There were significant differences in knee extensor strength and balance ability between the pre- and post-treatment of all groups (p<.05). The improvement of knee extensor strength was significantly higher in the OKC group than in the other groups (p<.05), and the improvement of dynamic balance was significantly higher in the CKC group than in the other groups (p<.05). CONCLUSION: These results showed that both open and closed kinetic chain exercises are effective in the improvement of knee extensor strength and balance ability. This study suggests that open and closed kinetic exercise training is an effective training for strength and balance in patients with early stroke.

The effects of closed kinetic chain exercise and open kinetic chain exercise in improving the balance of patients with hemiplegia (닫힌 사슬운동과 열린 사슬운동이 편마비 환자의 균형에 미치는 영향)

  • Kim, Yong-Jeong;Kim, Taek-Yean;Oh, Duck-Won
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.15 no.1
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    • pp.22-31
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    • 2009
  • Purpose The purpose of this study was to compare the effects of closed kinetic chain exercise and open kinetic chain exercise in improving the balance of patients with hemiplegia. Methods Ten patients with stroke were randomly allocated to either a closed kinetic chain exercise (CKC) group(n=5) or an open kinetic chain exercise(OKC) group(n=5). The subjects of each group followed the exercise regimen of their respective groups, and each exercise was performed for 50 mins per day, 3 days per week, for 4 weeks. Assessment was made using Berg Balance Scale (BBS), One Leg Standing(OLS) test, and Timed up and go(TUG) test. The 2 groups were assessed twice: before and after the intervention. Results The TUG test score was significantly different in the CKC group between before and after intervention (p<.05); however, there was no such deference in the OKC group (p>.05). Further, the scores of the BBS and OLS tests were not significantly different for the 2 groups between before and after intervention (p>.05). The hanges in these BBS and OLS score were not significantly different(p>.05); however, there was a significant difference in the change in the TUG scores (p<.05). Conclusion On the basis of the results of this study, we found that the closed kinetic chain exercise is more effective in improving the walking ability and dynamic balance in patients with stroke. Future studies are warranted in this regard.

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The Effect of Supply Chain Dynamic Capabilities, Open Innovation and Supply Uncertainty on Supply Chain Performance (공급사슬 동적역량, 개방형 혁신, 공급 불확실성이 공급사슬 성과에 미치는 영향)

  • Lee, Sang-Yeol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.481-491
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    • 2018
  • As the global business environment is dynamic, uncertain, and complex, supply chain management determines the performance of the supply chain in terms of the utilization of resources and capabilities of companies involved in the supply chain. Companies pursuing open innovation gain greater access to the external environment and accumulate knowledge flows and learning experiences, and may generate better business performance from dynamic capabilities. This study analyzed the effects of supply chain dynamic capabilities, open innovation, and supply uncertainty on supply chain performance. Through questionnaires on 178 companies listed on KOSDAQ, empirical results are as follows: First, integration and reactivity capabilities among supply chain dynamic capabilities have a positive effect on supply chain performance. Second, the moderating effect of open innovation showed a negative correlation in the case of information exchange, and a positive correlation in the cases of integration, cooperation and reactivity. Third, two of the 3-way interaction terms, "information exchange*open innovation*supply uncertainty" and "integration*open innovation*supply uncertainty" were statistically significant. The implications of this study are as follows: First, as the supply chain needs to achieve optimization of the whole process between supply chain components rather than individual companies, dynamic capabilities play an important role in improving performance. Second, for KOSDAQ companies featuring limited capital resources, open innovation that integrates external knowledge is valuable. In order to increase synergistic effects, it is necessary to develop dynamic capabilities accordingly. Third, since resources are constrained, managers must determine the type or level of capabilities and open innovation in accordance with supply uncertainty. Since this study has limitations in analyzing survey data, it is necessary to collect secondary data or longitudinal data. It is also necessary to further analyze the internal and external factors that have a significant impact on supply chain performance.

Difference of Proprioceptive Sense at Elbow Joint According to Measurement Methods (팔굽관절에서 측정방법에 따른 고유수용성감각 차이)

  • Lee, Jung-Ah;Kim, Duk-Hwa;Shin, Hwa-Kyung;Choi, Kyu-Hwan;Kwon, Oh-Yun
    • Physical Therapy Korea
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    • v.10 no.3
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    • pp.63-70
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    • 2003
  • The purpose of this study was to compare the difference of joint position sense between measurements. Fourteen healthy male subjects were recruited for this study. The elbow joint position senses were measured using angle reproduction test. The elbow joint position sense was assessed with three experimental conditions: ipsilateral reproduction test in open-chain condition, contralateral reproduction test in open-chain condition, ipsilateral reproduction test with weight in open-chain condition and ipsilateral reproduction test in closed-chain condition. The angular difference between stimulus position and the reproduced position (angular error) was calculated in all testing conditions to examine the accuracy of the joint position sense. One way ANOVA was used to compare the error angles in all experimental conditions. The error angles between measurements were significantly different in elbow joint. The error angles was smallest in ipsilateral reproduction test with weight in open-chain condition and was greatest in the contralateral reproduction test in open-chain condition. Findings of this study indicate that testing methods, types of task, existence of resistance should be considered in clinical assessment for the joint position sense.

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Mass Spectrometry of Dammarane Triterpenoids (Dammarane계(係) Triterpenoid의 질량분광분석(質量分光分析))

  • Han, Byung-Hoon;Kim, Jae-Hoon;Chi, Hyung-Joon
    • Korean Journal of Pharmacognosy
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    • v.10 no.2
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    • pp.55-59
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    • 1979
  • Mass spectra of the dammarane triterpenes having open side chain and $C_{20}-C_{25}-epoxy$ side chain were measured. Principal fragment ions were assigned and plausible mechanisms for the formation of the fragment ions were proposed. In general, the triter-penoids of $C_{20}-C_{25}-epoxy$ side chain. produce $h_{1}-species$ fragment ions by the deletion of side chain at $C_{20}-C_{22}$ bond and open side chain triterpenoids produce $h_{2}$ species fragmentions whose mass numbers are higher by two mass unit than those of $h_{1}$ species. The mass number of h species fragment ions will serve as the diagnostic tool for the elucidation of side chain structure of tetracyclic triterpenoids.

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The Effects of Closed Kinetic and Open Kinetic Chain Exercises Using Knee Reposition Sense in Chronic Stroke Patients

  • Lee, Kyu-Young;Shin, Won-Seob
    • The Journal of Korean Physical Therapy
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    • v.26 no.3
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    • pp.182-190
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    • 2014
  • Purpose: This study aimed to determine the effects of open kinetic chain exercise (OKCE) and closed kinetic chain exercise (CKCE) using knee reposition sensing on balance, strength, and knee joint reposition sense (JPS) in chronic stroke patients. Methods: Twenty-nine hemiplegic patients participated in this study. Participants were randomly divided into 3 groups, CKCE, OKCE, and controls, with 9, 10, and 10 participants, respectively. The CKCE group completed CKCE using knee reposition sensing, whereas the OKCE group completed OKCE using knee reposition sensing. The control group completed conventional physical therapy. Results: Significant differences between the CKCE and OKCE groups were apparent for all outcomes except the functional reaching test. The CKCE group displayed significant improvements in knee JPS versus the OKCE and control groups (p<0.01). The OKCE group displayed significant improvements in knee extensor muscle strength versus the CKCE and control groups (p<0.05). The CKCE and OKCE groups displayed significantly improvements in static balance versus the control group (p<0.05). Conclusion: CKCE and OKCE improved balance, strength, and knee JPS. Additionally, CKCE might provide a more useful intervention benefit than OKCE for increasing knee JPS, a weight-bearing task. OKCE was sufficient to improve the knee extensor muscle strength.