• Title/Summary/Keyword: Dynamic Control

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Evaluation of storage period of fresh ginseng for quality improvement of dried and red processed varieties

  • Zhang, Na;Huang, Xin;Guo, Yun-Long;Yue, Hao;Chen, Chang-Bao;Liu, Shu-Ying
    • Journal of Ginseng Research
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    • v.46 no.2
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    • pp.290-295
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    • 2022
  • Background: Dried and red ginseng are well-known types of processed ginseng and are widely used as healthy food. The dried and red ginseng quality may vary with the storage period of raw ginseng. Therefore, herein, the effect of the storage period of fresh ginseng on processed ginseng quality was evaluated through multicomponent quantification with statistical analysis. Methods: A method based on ultrahigh performance liquid chromatography coupled to triple quadrupole mass spectrometry in multiple-reaction monitoring mode (UPLC-MRM-MS) was developed for quantitation of ginsenosides and oligosaccharides in dried and red ginseng. Principal component analysis and partial least squares discriminant analysis were conducted to evaluate the dynamic distributions of ginsenosides and oligosaccharides after different storage periods. Results: Eighteen PPD, PPT and OLE ginsenosides and nine reducing and nonreducing oligosaccharides were identified and quantified. With storage period extension, the ginsenoside content in the processed ginseng increased slightly in the first 2 weeks and decreased gradually in the following 9 weeks. The content of reducing oligosaccharides decreased continuously as storage time extending, while that of the nonreducing oligosaccharides increased. Chemical conversions occurred during storage, based on which potential chemical markers for the storage period evaluation of fresh ginseng were screened. Conclusion: According to ginsenoside and oligosaccharide distributions, it was found that the optimal storage period was 2 weeks and that the storage period of fresh ginseng should not exceed 4 weeks at 0 ℃. This study provides deep insights into the quality control of processed ginseng and comprehensive factors for storage of raw ginseng.

Real Time Fault Diagnosis of UAV Engine Using IMM Filter and Generalized Likelihood Ratio Test (IMM 필터 및 GLRT를 이용한 무인기용 엔진의 실시간 결함 진단)

  • Han, Dong-Ju;Kim, Sang-Jo;Kim, Yu-Il;Lee, Soo-Chang
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.50 no.8
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    • pp.541-550
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    • 2022
  • An effective real time fault diagnosis approach for UAV engine is drawn from IMM filter and GLRT methods. For this purpose based on the linear diagnosis model derived from engine dynamic performance analysis the Kalman filter for residual estimation and each method are applied to the fault diagosis of the actuator for engine control sensors. From the process of the IMM filter application the effective FDI measure is obtained and the state responses due to actuator fault are estimated. Likewise from the GLRT method the fault magnitudes of actuator and sensors are estimated associated with some FDI functionings. The numerical simulations verify the effectiveness of the IMM filter for FDI and the GLRT in estimating the fault magnitudes of each fault mode.

The Impact of Optical Illusions on the Vestibular System

  • Ozturk, Seyma Tugba;Serbetcioglu, Mustafa Bulent;Ersin, Kerem;Yilmaz, Oguz
    • Journal of Audiology & Otology
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    • v.25 no.3
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    • pp.152-158
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    • 2021
  • Background and Objectives: Balance control is maintained in stationary and dynamic conditions, with coordinated muscle responses generated by somatosensory, vestibular, and visual inputs. This study aimed to investigate how the vestibular system is affected in the presence of an optical illusion to better understand the interconnected pathways of the visual and vestibular systems. Subjects and Methods: The study involved 54 young adults (27 males and 27 females) aged 18-25 years. The recruited participants were subjected to the cervical vestibular evoked myogenic potentials (cVEMP) test and video head impulse test (vHIT). The cVEMP and vHIT tests were performed once each in the absence and presence of an optical illusion. In addition, after each test, whether the individuals felt balanced was determined using a questionnaire. Results: cVEMP results in the presence of the optical illusion showed shortened latencies and increased amplitudes for the left side in comparison to the results in the absence of the optical illusion (p≤0.05). When vHIT results were compared, it was seen that the right lateral and bilateral anterior canal gains were increased, almost to 1.0 (p<0.05). Conclusions: It is thought that when the visual-vestibular inputs are incompatible with each other, the sensory reweighting mechanism is activated, and this mechanism strengthens the more reliable (vestibular) inputs, while suppressing the less reliable (visual) inputs. As long as the incompatible condition persists, the sensory reweighting mechanism will continue to operate, thanks to the feedback loop from the efferent vestibular system.

Real-time System Identification of Aircraft in Upset Condition Using Adaptive-order Zonotopic Kalman Filter (적응 차수 조노토픽 칼만 필터를 활용한 비정상 비행상태 항공기의 실시간 시스템 식별)

  • Gim, Seongmin;Harno, Hendra G.;Saderla, Subrahmanyam;Kim, Yoonsoo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.50 no.2
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    • pp.93-101
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    • 2022
  • It is essential to prevent LoC(Loss-of-Control) or upset situations caused by stall, icing or sensor malfunction in aircraft, because it may lead to the crash of the aircraft. With this regard, it is crucial to correctly identify the dynamic characteristics of aircraft in such upset conditions. In this paper, we present a SID(System IDentification) method utilizing the moving-window based least-square and the adaptive-order ZKF(Zonotopic Kalman Filter), which is more effective than the existing Kalman-filter based SID for the aircraft in upset condition at a high angle of attack with temporary sensor malfunction. The proposed method is then tested on real flight data and compared with the existing one.

Physical Properties of Liquid Ammonia Wood for Bending (휨가공을 위한 액체암모니아 처리재의 물리적 성질)

  • Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.31 no.1
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    • pp.52-60
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    • 2003
  • The physical properties of small hardwood and softwood specimens treated with liquid ammonia were investigated. The specimens treated for 4 or 18 hours were compared with the controls. The EMCs of the liquid ammonia treated specimens were higher than those of the controls when conditioned at the same humidities. However once oven-dried they didn't show any significant differences in EMCs. With the increase of liquid ammonia treatment time specimens shrank in radial and tangential directions, but not in longitudinal direction. As liquid ammonia treatment time increased the ultrasonic velocities of specimens decreased and their densities increased, thus their dynamic MOEs decreased. For chestnut specimens the presteamed were more plasticized than the liquid ammonia treated. Incising on the surfaces of specimens didn't improve liquid ammonia permeability in both hardwoods and softwoods. Liquid ammonia treatment was very effective for plasticizing 5 mm thick softwoods. Relative dielectric constants and thermal conductivities were measured with both liquid ammonia treated and control specimens.

Applying Least Mean Square Method to Improve Performance of PV MPPT Algorithm

  • Poudel, Prasis;Bae, Sang-Hyun;Jang, Bongseog
    • Journal of Integrative Natural Science
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    • v.15 no.3
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    • pp.99-110
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    • 2022
  • Solar photovoltaic (PV) system shows a non-linear current (I) -voltage (V) characteristics, which depends on the surrounding environment factors, such as irradiance, temperature, and the wind. Solar PV system, with current (I) - voltage (V) and power (P) - Voltage (V) characteristics, specifies a unique operating point at where the possible maximum power point (MPP) is delivered. At the MPP, the PV array operates at maximum power efficiency. In order to continuously harvest maximum power at any point of time from solar PV modules, a good MPPT algorithms need to be employed. Currently, due to its simplicity and easy implementation, Perturb and Observe (P&O) algorithms are the most commonly used MPPT control method in the PV systems but it has a drawback at suddenly varying environment situations, due to constant step size. In this paper, to overcome the difficulties of the fast changing environment and suddenly changing the power of PV array due to constant step size in the P&O algorithm, least mean Square (LMS) methods is proposed together with P&O MPPT algorithm which is superior to traditional P&O MPPT. PV output power is predicted using LMS method to improve the tracking speed and deduce the possibility of misjudgment of increasing and decreasing the PV output. Simulation results shows that the proposed MPPT technique can track the MPP accurately as well as its dynamic response is very fast in response to the change of environmental parameters in comparison with the conventional P&O MPPT algorithm, and improves system performance.

The Impact of Optical Illusions on the Vestibular System

  • Ozturk, Seyma Tugba;Serbetcioglu, Mustafa Bulent;Ersin, Kerem;Yilmaz, Oguz
    • Korean Journal of Audiology
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    • v.25 no.3
    • /
    • pp.152-158
    • /
    • 2021
  • Background and Objectives: Balance control is maintained in stationary and dynamic conditions, with coordinated muscle responses generated by somatosensory, vestibular, and visual inputs. This study aimed to investigate how the vestibular system is affected in the presence of an optical illusion to better understand the interconnected pathways of the visual and vestibular systems. Subjects and Methods: The study involved 54 young adults (27 males and 27 females) aged 18-25 years. The recruited participants were subjected to the cervical vestibular evoked myogenic potentials (cVEMP) test and video head impulse test (vHIT). The cVEMP and vHIT tests were performed once each in the absence and presence of an optical illusion. In addition, after each test, whether the individuals felt balanced was determined using a questionnaire. Results: cVEMP results in the presence of the optical illusion showed shortened latencies and increased amplitudes for the left side in comparison to the results in the absence of the optical illusion (p≤0.05). When vHIT results were compared, it was seen that the right lateral and bilateral anterior canal gains were increased, almost to 1.0 (p<0.05). Conclusions: It is thought that when the visual-vestibular inputs are incompatible with each other, the sensory reweighting mechanism is activated, and this mechanism strengthens the more reliable (vestibular) inputs, while suppressing the less reliable (visual) inputs. As long as the incompatible condition persists, the sensory reweighting mechanism will continue to operate, thanks to the feedback loop from the efferent vestibular system.

Deletion of adipose triglyceride lipase abolishes blood flow increase after β3-adrenergic stimulation in visceral adipose tissue of mice

  • Lee, Hye-Jin;Jin, Bo-Yeong;Park, Mi-Rae;Seo, Kwan Sik;Jeong, Yong Taek;Choi, Sang-Hyun;Kim, Dong-Hoon
    • The Korean Journal of Physiology and Pharmacology
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    • v.25 no.4
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    • pp.355-363
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    • 2021
  • Dynamic changes in adipose tissue blood flow (ATBF) with nutritional status play a role in the regulation of metabolic and endocrine functions. Activation of the sympathetic nervous system via β-adrenergic receptors (β-AR) contributes to the control of postprandial enhancement of ATBF. Herein, we sought to identify the role of each β-AR subtype in the regulation of ATBF in mice. We monitored the changes in visceral epididymal ATBF (VAT BF), induced by local infusion of dobutamine, salbutamol, and CL316,243 (a selective β1-, β2-, and β3-AR agonist, respectively) into VAT of lean CD-1 mice and global adipose triglyceride lipase (ATGL) knockout (KO) mice, using laser Doppler flowmetry. Administration of CL316,243, known to promote lipolysis in adipocytes, significantly increased VAT BF of CD-1 mice to a greater extent compared to that of the vehicle, whereas administration of dobutamine or salbutamol did not produce significant differences in VAT BF. The increase in VAT BF induced by β3-AR stimulation disappeared in ATGL KO mice as opposed to their wild-type (WT) littermates, implying a role of ATGL-mediated lipolysis in the regulation of VAT BF. Different vascular reactivities occurred despite no significant differences in vessel density and adiposity between the groups. Additionally, the expression levels of the angiogenesis-related genes were significantly higher in VAT of ATGL KO mice than in that of WT, implicating an association of ATBF responsiveness with angiogenic activity in VAT. Our findings suggest a potential role of β3-AR signaling in the regulation of VAT BF via ATGL-mediated lipolysis in mice.

A generalized adaptive variational mode decomposition method for nonstationary signals with mode overlapped components

  • Liu, Jing-Liang;Qiu, Fu-Lian;Lin, Zhi-Ping;Li, Yu-Zu;Liao, Fei-Yu
    • Smart Structures and Systems
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    • v.30 no.1
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    • pp.75-88
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    • 2022
  • Engineering structures in operation essentially belong to time-varying or nonlinear structures and the resultant response signals are usually non-stationary. For such time-varying structures, it is of great importance to extract time-dependent dynamic parameters from non-stationary response signals, which benefits structural health monitoring, safety assessment and vibration control. However, various traditional signal processing methods are unable to extract the embedded meaningful information. As a newly developed technique, variational mode decomposition (VMD) shows its superiority on signal decomposition, however, it still suffers two main problems. The foremost problem is that the number of modal components is required to be defined in advance. Another problem needs to be addressed is that VMD cannot effectively separate non-stationary signals composed of closely spaced or overlapped modes. As such, a new method named generalized adaptive variational modal decomposition (GAVMD) is proposed. In this new method, the number of component signals is adaptively estimated by an index of mean frequency, while the generalized demodulation algorithm is introduced to yield a generalized VMD that can decompose mode overlapped signals successfully. After that, synchrosqueezing wavelet transform (SWT) is applied to extract instantaneous frequencies (IFs) of the decomposed mono-component signals. To verify the validity and accuracy of the proposed method, three numerical examples and a steel cable with time-varying tension force are investigated. The results demonstrate that the proposed GAVMD method can decompose the multi-component signal with overlapped modes well and its combination with SWT enables a successful IF extraction of each individual component.

Impacts of Transparency and Disclosures on Firm Valuation of the Healthcare Sector in India

  • Saumya, SINGH;Pracheta, TEJASMAYEE;Venkata Mrudula, BHIMAVARAPU;Arpita, SHARMA;Rameesha, KALRA;Sanjeev, KADAM;Poornima, TAPAS;Shailesh, RASTOGI
    • The Journal of Asian Finance, Economics and Business
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    • v.10 no.2
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    • pp.153-161
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    • 2023
  • This study's principal goal is to find the interrelation between transparency & disclosure (TD) and the healthcare sector's firm valuation (FV). The paper uses the market-to-book (MTB) ratio and market capitalization as proxies, where sales measure act as a control variable. Dynamic panel data regression (PD) is the method applied for analyzing data. Data pertains to 10 healthcare companies gathered over five years (2016-2020). Results imply that TD has a negative and significant influence on the FV, where market capitalization acts as a proxy for valuation. This association indicates that a greater degree of TD diminishes FV. TD is also reported to have a negative and insignificant association with MTB. Therefore, TD does not influence FV. The findings of this paper have significant practical implications. Results can help policymakers determine mandatory disclosure levels that are not detrimental to the healthcare sector. Managers and analysts must also analyze the dimensions of disclosure that can negatively impact the firm's valuation and make decisions regarding TD accordingly. This is the first study to assess the influence of TD on the FV of the Indian healthcare sector, which makes it unique. This study is limited to the healthcare sector, which is its shortcoming.