• Title/Summary/Keyword: Dynamic stabilization

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Ab initio and DFT Study for the Internal Rotations of Cyclopropyldifluoroborane Molecule (Cyclopropyldifluoroborane 분자의 내부회전에 대한 이론적인 연구)

  • Kim, Gyeong-Lee;Lee, Jeong-Gyeong
    • Journal of the Korean Chemical Society
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    • v.50 no.4
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    • pp.291-297
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    • 2006
  • The equilibrium structures, relative energies and NBO analyses for the possible conformations and transition states which can exist on the internal rotation of CPDFB and CPCFB molecules have been investigated using DFT and ab initio methods with various basis sets. The interaction between bonding orbital ((C1-C3, C2-C3)) and antibonding orbital (n*(B9) and *(B9-Cl11)) was the main characteristic hyperconjugation in both molecules. In addition, the stabilization energy of CPDFB was 6.63kcal/mol and that of CPCFB was 6.97(E-form)/6.79(Z-form) kcal/mol for each conformation. The rotational barriers by internal rotation of BF2- and BFCl- functional groups were evaluated to be 5.3~6.7kcal/mol and 5.7~6.5kcal/mol respectively, which showed good agreement with the experimental values reported by previous dynamic NMR study. Finally, Z-form was more stable than E-form by 0.2 kcal/mol in CPCFB molecule and therefore Z-form was confirmed as global minimum.

A Study on the Low-Cost Fiber-Optic Gyroscope Using the Single Mode Fiber and Depolarizer (단일모드 광섬유와 편광소멸기를 이용한 저가형 광섬유 자이로스코프에 관한 연구)

  • Jang, Nam-Young;Ham, Hyung-Jae;Song, Hui-Young;Chio, Pyung-Suk;Eun, Jae-Jeong
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.3
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    • pp.179-187
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    • 2008
  • In this paper, we carried out the performance evaluation of depolarized fiber optic gyroscope(D-FOG) that was designed and fabricated with the low-cost optical communication single mode fiber and depolarizer. In order to reduce the phase error of D-FOG, the circuit of stabilized current and temperature of the light source was made and the performance was analyzed. The current and the temperature stability of the fabricated stabilization circuit were less than $200{\mu}A$ and $0.0098^{\circ}C$, respectively. Also, the D-FOG's experimental result showed that the value of the dynamic range of rotated rate, the scale factor error with a good linearity, and the zero bias drift were ${\pm}50^{\circ}/s$, 2.8881%, and $19.49^{\circ}/h$, respectively. The results indicated that a low-cost FOG was able to fabricate which was more cost effective than conventional FOG with a high-cost high-birefringent polarization maintaining fiber.

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Effect of citrate coated silver nanoparticles on biofilm degradation in drinking water PVC pipelines

  • Nookala, Supraja;Tollamadugu, Naga Venkata Krishna Vara Prasad;Thimmavajjula, Giridhara Krishna;Ernest, David
    • Advances in nano research
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    • v.3 no.2
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    • pp.97-109
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    • 2015
  • Citrate ion is a commonly used reductant in metal colloid synthesis, undergoes strong surface interaction with silver nanocrystallites. The slow crystal growth observed as a result of the interaction between the silver surface and the citrate ion makes this reduction process unique compared to other chemical and radiolytic synthetic methods. The antimicrobial effects of silver (Ag) ion or salts are well known, but the effects of citrate coated Ag nanoparticles (CAgNPs) are scant. Herein, we have isolated biofilm causative bacteria and fungi from drinking water PVC pipe lines. Stable CAgNPs were prepared and the formation of CAgNPs was confirmed by UV-visible spectroscopic analysis and recorded the localized surface plasmon resonance of CAgNPs at 430 nm. Fourier transform infrared spectroscopic analysis revealed C=O and O-H bending vibrations due to organic capping of silver responsible for the reduction and stabilization of the CAgNPs. X-ray diffraction micrograph indicated the face centered cubic structure of the formed CAgNPs, and morphological studies including size (average size 50 nm) were carried out using transmission electron microscopy. The hydrodynamic diameter (60.7 nm) and zeta potential (-27.6 mV) were measured using the dynamic light scattering technique. The antimicrobial activity of CAgNPs was evaluated (in vitro) against the isolated fungi, Gram-negative and Gram-positive bacteria using disc diffusion method and results revealed that CAgNPs with 170ppm concentration are having significant antimicrobial effects against an array of microbes tested.

Design of The Autopilot System of vessel using Fuzzy Algorithm (퍼지제어 알고리즘을 이용한 선박의 자율운항 시스템 설계)

  • 이민수;추연규;이광석;김현덕;박연식
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.7
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    • pp.1509-1513
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    • 2003
  • The autopilot system of vessel is proposed to take service safety and security, to elevate service efficiency, to decrease labor and to improve working environment. Ultimate purpose of the proposed system is to minimize the number of crew by guaranteeing economical efficiency of shipping service. Recently, the research is being achieved to compensate various nonlinear parameters of vessel and apply it to course keeping control, track keeping control, roll-rudder stabilization, dynamic ship positioning and automatic mooring control etc. using optimizing control technique. Relation between rudder angle controlled by steering machine of vessel and ship-heading angle, and load condition of ship is nonlinear, which affects various parameters of shipping service. The speed and direction of waves, velocity and quantity of wind, which also cause the non-linearity of it. Therefore the autopilot system of ship requires the robust control algorithm can overcome various non-linearity. On this paper, we design the autopilot system of ship, which overcomes nonlinear Parameters and disturbance of it using Fuzzy Algorithm, evaluate the proposed algorithm and its excellence through simulation.

Application of Horizontal Flow Fins Inclined Plate for Sedimentation Efficiencies Improvement in River Water with High Turbidity (고탁도 원수의 침전효율 증대를 위한 수평류식 핀 경사판 적용에 관한 연구)

  • Choi, Jung-Su;Jin, Oh-Suk;Joo, Hyun-Jong
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.9
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    • pp.644-650
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    • 2012
  • The purpose of this study is to evaluate the applicability of Horizontal Flow Fins Inclined Plate (HFIP) for the removal of high-turbidity raw water in water treatment plant. As an experimental result, treated water quality and removal efficiency were 0.34 NTU and 90.45% by the application of HFIP for low-turbidity raw water and for the high-turbidity influent resulted 0.75 NTU and 97.27% in removal efficiency. In view of stability for discharge water NTU, the standard deviation were found as 0.12 NTU for low-turbidity and 0.75 NTU for high-turbidity raw water indicating low fluctuations. Result of flow analysis using CFD (Computational Fluid Dynamic) that the addition of HFIP improves the turbidity treatment followed by the stabilization of flow velocity distribution and increases in settling velocity.

Effect of Symmetrical Reciprocal Pattern of Scapula and Pelvis in PNF Concept on the Gait Speed and Balance of thePatients with Hemiplegia (PNF Concept중 Scapula and Pelvis의 Symmetrical Reciprocal Pattern이 Hemiplegia환자의 보행속도와 균형감각에 미치는 효과)

  • Maeng, Gwan-Cheol;Baek, Sun-Young
    • PNF and Movement
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    • v.13 no.2
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    • pp.73-80
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    • 2015
  • Purpose: The purpose of this study was to determine the effect of symmetrical-reciprocal pattern of scapula and pelvis exercises using proprioceptive neuromuscular facilitation (PNF) on gait speed and balance in patients with hemiplegia. Methods: Among the adult patients with hemiplegia that were hospitalized at Michuhol Rehabilitation Center after being diagnosed with stroke, 10 that were capable of independent walking for more than five minutes and that understood and cooperated with the therapy and test methods of this research, were selected as subjects. The therapy was implemented based on the concept of PNF, and it was performed on a low mat and a height-adjustable mat, as proscribed by the fundamental procedure for PNF. Symmetrical-reciprocal pattern of scapula and pelvis exercises were applied to the patients in the decubitus position. The therapy scheme included stabilizing reversals, rhythmic stabilization, and a combination of isotonics, rhythmic initiation, and dynamic reversals. To investigate gait speed and body trunk mobility before and after the symmetrical-reciprocal pattern of scapula and pelvis exercises were applied, walking speed for a distance of 10 m was measured and balance was tested based on the Berg-Balance scale test table. The Berg-Balance scale test was performed by one therapist to minimize any error that could occur from the subjective evaluation method used by therapists. Results: Gait speed increased by 8.97 seconds after applying the symmetrical-reciprocal pattern of scapula and pelvis exercises using the concept of PNF, showing a significant difference (p<0.01). However, balance showed no significant difference after the therapy (p>0.14). Conclusion: Exercise therapy that uses the symmetrical-reciprocal pattern of scapula and pelvis with the concept of PNF can be said to be a useful therapeutic technique that can enhance the walking speed of patients with hemiplegia.

Short-term effects of joint mobilization with versus without voluntary movement in patients with chronic ankle instability: A single-blind randomized controlled trial

  • Kim, Hyunjoong;Song, Seonghyeok;Lee, Sangbong;Lee, Seungwon
    • Physical Therapy Rehabilitation Science
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    • v.10 no.1
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    • pp.1-9
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    • 2021
  • Objective: Joint mobilization for arthrokinematics altered by the positional fault of chronic ankle instability (CAI) is an effective intervention for stabilization. In this study, we compared the effects of ankle dorsi flexion range of motion (DFROM) and dynamic balance ability (DBA) in CAI patients via passive joint mobilization (PJM), a method traditionally performed in previous studies, and active joint mobilization (AJM), a method that can have a greater effect on cortical excitability with spontaneous movements. Design: Single-blind two-arm randomized controlled trial Methods: A total of 30 participants were registered: 15 each to the PJM and AJM groups. Each participant received a total of 10 intervention sessions, 10 minutes per session, 5 times a week for 2 weeks. PJM used Maitland's mobilization method to apply joint mobilization with talus in the posterior direction and AJM used an angular joint motion to induce patient's voluntary motion of medial malleolus anterior gliding and lateral malleolus posterior gliding, respectively. DFROM of the ankle was measured by using tape and DBA was evaluated by using the balance system. Results: Significant improvement was observed after intervention in both the PJM and AJM groups except for the DBA-anterior and DBA-right variables of the PJM group. There were statistically significant differences between the AJM and PJM groups in the DFROM, DBA-anterior, DBA-posterior, and DBA-right variables. Conclusions: The overall improvement of DFROM and DBA was found to be more effective in joint mobilization including voluntary movement. When it is accompanied by voluntary movement, it further affects the neuromuscular system of the ankle.

Nonlinear Optimization Analysis of the Carryover Policy in the 2nd Compliance Period of the Korean Emissions Trading Scheme (배출권거래제 2차 계획기간 중 이월한도 정책에 대한 비선형최적화 분석)

  • Jongmin Yu;Seojin Lee
    • Environmental and Resource Economics Review
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    • v.32 no.3
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    • pp.149-166
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    • 2023
  • The emissions trading system, introduced to reduce greenhouse gas emissions, experienced a sharp increase in emission allowance prices during the second plan period (2018-2020), which led to an increase in the demand for smooth supply and demand of emission allowances, while suppliers anticipating a shortage of emission allowances in the future did not participate in trading. Therefore, the authority temporarily revised the guidelines to ensure that the amount of allowances carried forward is proportional to the trading volume as a market stabilization measure. Through an optimization process using a dynamic nonlinear mathematical model, this paper analyzes the impact of the government's intervention on the carryover policy on GHG emission reductions and emission allowance market prices. According to the simulation analysis results, banking regulations could cause a decline in prices during the regulation period, even though the initial policy was predicted to be adopted.

Study of Speed Profile for Dynamic Stability of EOTS (EOTS의 동적 안정성을 위한 속도 프로파일에 대한 연구)

  • Gyu-Chan Lee;Dong-Gi Kwag
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.6
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    • pp.919-925
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    • 2023
  • Modern drones are equipped with miniaturized mission equipment capable of performing various tasks such as surveillance and reconnaissance. Consequently, these mission equipment are exposed to disturbances like wind loads and motor rotations, which can lead to instability in the operation of the Electro-Optical Targeting System (EOTS). Specifically, simple step inputs for changing the line of sight in EOTS can cause abrupt changes in speed, inducing overshoot and potentially creating instability along with other disturbances. To address this, a velocity profile was designed so that the angular velocity moves in a trapezoidal shape when changing the EOTS line of sight. A Double-loop controller was designed to apply this profile as an input to the external loop receiving position feedback. The system's stability was then compared, and the velocity profile was optimized within a stable range by varying maximum speed and acceleration.

Nasal Immunization Using Chitosan Nanoparticles with Glycoprotein B of Murine Cytomegalovirus

  • Marcela Slovakova;Sylva Janovska;Radek Sleha;Vera Radochova;Alexandra Hatala;Nikola Mannova;Radovan Metelka;Ludovit Pudelka;Pavel Bostik
    • Journal of Microbiology and Biotechnology
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    • v.34 no.3
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    • pp.663-672
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    • 2024
  • The use of nanoparticles as a delivery system for a specific antigen could solve many limitations of mucosal vaccine applications, such as low immunogenicity, or antigen protection and stabilization. In this study, we tested the ability of nasally administered chitosan nanoparticles loaded with glycoprotein B of murine cytomegalovirus to induce an immune response in an animal model. The choice of chitosan nanoparticle type was made by in vitro evaluation of sorption efficiency and antigen release. Three types of chitosan nanoparticles were prepared: crosslinked with tripolyphosphate, coated with hyaluronic acid, and in complex with polycaprolactone. The hydrodynamic size of the nanoparticles by dynamic light scattering, zeta potential, Fourier transform infrared spectroscopy, scanning electron microscopy, stability, loading efficiency, and release kinetics with ovalbumin were evaluated. Balb/c mice were immunized intranasally using the three-dose protocol with nanoparticles, gB, and adjuvants Poly(I:C) and CpG ODN. Subsequently, the humoral and cell-mediated antigen-specific immune response was determined. On the basis of the properties of the tested nanoparticles, the cross-linked nanoparticles were considered optimal for further investigation. The results show that nanoparticles with Poly(I:C) and with gB alone raised IgG antibody levels above the negative control. In the case of mucosal IgA, only gB alone weakly induced the production of IgA antibodies compared to saline-immunized mice. The number of activated cells increased slightly in mice immunized with nanoparticles and gB compared to those immunized with gB alone or to negative control. The results demonstrated that chitosan nanoparticles could have potential in the development of mucosal vaccines.