• Title/Summary/Keyword: Envelope method

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Empirical Mode Decomposition using the Second Derivative (이차 미분을 이용한 경험적 모드분해법)

  • Park, Min-Su;Kim, Donghoh;Oh, Hee-Seok
    • The Korean Journal of Applied Statistics
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    • v.26 no.2
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    • pp.335-347
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    • 2013
  • There are various types of real world signals. For example, an electrocardiogram(ECG) represents myocardium activities (contraction and relaxation) according to the beating of the heart. ECG can be expressed as the fluctuation of ampere ratings over time. A signal is a composite of various types of signals. An orchestra (which boasts a beautiful melody) consists of a variety of instruments with a unique frequency; subsequently, each sound is combined to form a perfect harmony. Various research on how to to decompose mixed stationary signals have been conducted. In the case of non-stationary signals, there is a limitation to use methodologies for stationary signals. Huang et al. (1998) proposed empirical mode decomposition(EMD) to deal with non-stationarity. EMD provides a data-driven approach to decompose a signal into intrinsic mode functions according to local oscillation through the identification of local extrema. However, due to the repeating process in the construction of envelopes, EMD algorithm is not efficient and not robust to a noise, and its computational complexity tends to increase as the size of a signal grows. In this research, we propose a new method to extract a local oscillation embedded in a signal by utilizing the second derivative.

The Effects of Pilates Exercise on Static and Dynamic Balance in the Elderly

  • Park, Ji-Hye;Lee, Joong-Sook;Yang, Jeong-Ok;Lee, Bom-Jin;Bae, Kang-Ho;Shin, Jin-Hyung
    • Korean Journal of Applied Biomechanics
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    • v.26 no.4
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    • pp.397-405
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    • 2016
  • Objective: Pilates is a low/mid-intensity exercise that can be easily performed by elderly individuals as it is an individual body-oriented exercise. It is also a cardio workout that can be performed anywhere to develop strength and flexibility. Therefore, we investigated the effects of 8 week Pilates program on the balancing ability of elderly individuals. Method: The research participants were selected from elderly residents in B city. Ten individuals voluntarily signed an agreement to undergo free measurements as well as to participate in the workout program. (Height: $157.1{\pm}11.9cm$, Weight: $61.7{\pm}8.0kg$). The Pilates exercise was performed 60 minutes a day, three times a week for a total of eight weeks. The measurement variables used to test balance were the vestibular test, 5 m habitual and maximum walk test and 3 m tandem walk test. A series of paired t-test were conducted using IBM SPSS Statistics 23.0 to analyze all the research data collected in order to determine the balance ability of the participants before and after the Pilates program. Additionally, the statistically significant level for all analysis was set to ${\alpha}=.05$. Results: In the vestibular test, some meaningful changes were observed in the length envelope area (ENV) while standing on one foot, but there were no significant differences in the ENV, rectangle(REC), root mean square, and total length. Results also revealed that statistically significant differences existed in the 5 m habitual and maximum walk test, as well as the 3 m tandem walk test. Conclusion: To summarize the findings, the 8 week Pilates program employed in this study significantly improved the dynamic balance of the elderly participants. Thus, elderly individuals that frequent perform Pilates are expected to enjoy positive benefits such as increased balance and fewer falling accidents.

Efficiency Analysis of Convergence Research R&D Projects by Government-funded Research Institutes: Based on Data Envelopment Analysis (정부출연연구기관의 융합연구 R&D 사업에 대한 효율성 분석: 자료포락분석(Data Envelopment Analysis)에 기초하여)

  • Yuk, Hyoung-Gab;Kang, Dae-Seok;Yu, Myoung-San;Byun, Young-Jo
    • Knowledge Management Research
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    • v.22 no.4
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    • pp.237-260
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    • 2021
  • This study aims to make suggestions for more effective budget utilization and R&D project investment through verification of the efficiency of research results for the government's R&D projects. Efficiency was analyzed using Data Envelope Analysis(DEA) and 'Malmquist Index analysis' for the research results of convergence research projects organized by the National Science and Technology Research Association. The analysis targets were convergence research projects organized by the National Science and Technology Research Association and general entrusted research projects by government-funded research institutes, and dynamic analysis was conducted using DEA and Malmquist Index analysis. As a result of the analysis, the convergence research project showed high efficiency from the static perspective of DEA. On the other hand, from a dynamic perspective through the Malmquist Index analysis method, the efficiency of the general consignment project gradually declined, while the efficiency of the convergence research project improved every year. This suggests that convergence studies have higher results than general studies. Through the results of this study, we intend to present objective standards for performance evaluation of government R&D investment and provide objective implications for rational investment policies and research project planning of research personnel and research funds to improve efficiency for government-funded research institutes.

A Reliability Analysis of Shallow Foundations using a Single-Mode Performance Function (단일형 거동함수에 의한 얕은 기초의 신뢰도 해석 -임해퇴적층의 토성자료를 중심으로-)

  • 김용필;임병조
    • Geotechnical Engineering
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    • v.2 no.1
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    • pp.27-44
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    • 1986
  • The measured soil data are analyzed to the descriptive statistics and classified into the four models of uncorrelated-normal (UNNO), uncorrelated-nonnormal (VNNN), correlatedonnormal(CONN), and correlated-nonnormal(CONN) . This paper presents the comparisons of reliability index and check points using the advanced first-order second-moment method with respect to the four models as well as BASIC Program. A sin91e-mode Performance function is consisted of the basic design variables of bearing capacity and settlements on shallow foundations and input the above analyzed soil informations. The main conclusions obtained in this study are summarized as follows: 1. In the bearing capacity mode, cohesion and bearing-capacity factors by C-U test are accepted for normal and lognormal distribution, respectively, and negatively low correlated to each other. Since the reliability index of the CONN model is the lowest one of the four model, which could be recommended a reliability.based design, whereas the other model might overestimate the geotechnical conditions. 2. In the case of settlements mode, the virgin compression ratio and preccnsolidation pressure are fitted for normal and lognormal distribution, respectively. Constraining settlements to the lower ones computed by deterministic method, The CONN model is the lowest reliability of the four models.

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Evaluation of Viral Inactivation Efficacy of a Continuous Flow Ultraviolet-C Reactor (UVivatec) (연속 유동 Ultraviolet-C 반응기(UVivatec)의 바이러스 불활화 효과 평가)

  • Bae, Jung-Eun;Jeong, Eun-Kyo;Lee, Jae-Il;Lee, Jeong-Im;Kim, In-Seop;Kim, Jong-Su
    • Microbiology and Biotechnology Letters
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    • v.37 no.4
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    • pp.377-382
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    • 2009
  • Viral safety is an important prerequisite for clinical preparations of all biopharmaceuticals derived from plasma, cell lines, or tissues of human or animal origin. To ensure the safety, implementation of multiple viral clearance (inactivation and/or removal) steps has been highly recommended for manufacturing of biopharmaceuticals. Of the possible viral clearance strategies, Ultraviolet-C (UVC) irradiation has been known as an effective viral inactivating method. However it has been dismissed by biopharmaceutical industry as a result of the potential for protein damage and the difficulty in delivering uniform doses. Recently a continuous flow UVC reactor (UVivatec) was developed to provide highly efficient mixing and maximize virus exposure to the UV light. In order to investigate the effectiveness of UVivatec to inactivate viruses without causing significant protein damage, the feasibility of the UVC irradiation process was studied with a commercial therapeutic protein. Recovery yield in the optimized condition of $3,000\;J/m^2$ irradiation was more than 98%. The efficacy and robustness of the UVC reactor was evaluated with regard to the inactivation of human immunodeficiency virus (HIV), hepatitis A virus (HAV), bovine herpes virus (BHV), bovine viral diarrhea virus (BVDV), porcine parvovirus (PPV), bovine parvovirus (BPV), minute virus of mice (MVM), reovirus type 3 (REO), and bovine parainfluenza virus type 3 (BPIV). Non enveloped viruses (HAV, PPV, BPV, MVM, and REO) were completely inactivated to undetectable levels by $3,000\;J/m^2$ irradiation. Enveloped viruses such as HIV, BVDV, and BPIV were completely inactivated to undetectable levels. However BHV was incompletely inactivated with slight residual infectivity remaining even after $3,000\;J/m^2$ irradiation. The log reduction factors achieved by UVC irradiation were ${\geq}3.89$ for HIV, ${\geq}5.27$ for HAV, 5.29 for BHV, ${\geq}5.96$ for BVDV, ${\geq}4.37$ for PPV, ${\geq}3.55$ for BPV, ${\geq}3.51$ for MVM, ${\geq}4.20$ for REO, and ${\geq}4.15$ for BPIV. These results indicate that UVC irradiation using UVivatec was very effective and robust in inactivating all the viruses tested.