• 제목/요약/키워드: Sampled-data system

검색결과 351건 처리시간 0.032초

Risk of Cancer Mortality according to the Metabolic Health Status and Degree of Obesity

  • Oh, Chang-Mo;Jun, Jae Kwan;Suh, Mina
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권22호
    • /
    • pp.10027-10031
    • /
    • 2014
  • Background: We investigated the risk of cancer mortality according to obesity status and metabolic health status using sampled cohort data from the National Health Insurance system. Materials and Methods: Data on body mass index and fasting blood glucose in the sampled cohort database (n=363,881) were used to estimate risk of cancer mortality. Data were analyzed using a Cox proportional hazard model (Model 1 was adjusted for age, sex, systolic blood pressure, diastolic blood pressure, total cholesterol level and urinary protein; Model 2 was adjusted for Model 1 plus smoking status, alcohol intake and physical activity). Results: According to the obesity status, the mean hazard ratios were 0.82 [95% confidence interval (CI), 0.75-0.89] and 0.79 (95% CI, 0.72-0.85) for the overweight and obese groups, respectively, compared with the normal weight group. According to the metabolic health status, the mean hazard ratio was 1.26 (95% CI, 1.14-1.40) for the metabolically unhealthy group compared with the metabolically healthy group. The interaction between obesity status and metabolic health status on the risk of cancer mortality was not statistically significant (p=0.31). Conclusions: We found that the risk of cancer mortality decreased according to the obesity status and increased according to the metabolic health status. Given the rise in the rate of metabolic dysfunction, the mortality from cancer is also likely to rise. Treatment strategies targeting metabolic dysfunction may lead to reductions in the risk of death from cancer.

센싱 및 계측 기술에서의 혁신: 지구물리 탐사를 위한 압축센싱 및 초고해상도 기술 (A Breakthrough in Sensing and Measurement Technologies: Compressed Sensing and Super-Resolution for Geophysical Exploration)

  • 공승현;한승준
    • 지구물리와물리탐사
    • /
    • 제14권4호
    • /
    • pp.335-341
    • /
    • 2011
  • 탐사 시스템을 포함하여 대부분의 센싱 및 계측 시스템은 중요한 정보를 놓치지 않기 위하여 필요한 정보 보다 높은 샘플주기로 정보를 수집 한다. 이는 경우에 따라 센싱 및 계측 시스템이 비효율적일 수 있음을 의미한다. 본 논문에서는 적은 샘플자료로부터 높은 정밀도의 정보 취득에 관한 새로운 두 가지 연구분야를 소개하고자 한다. 하나는 가능한 적은 샘플로 원래의 정보를 복원하는 압축센싱(Compressed Sensing)기술이며, 또 다른 하나는 이미 얻어진 한정된 샘플로부터 높은 해상도의 정보를 추정하는 초고해상도(Super-Resolution)기술이다. 본 논문에서는 압축센싱 기술의 기본이론과 복원기술에 대해 설명하고, 탐사분야의 적용 사례, 초고해상도 기술의 배경 및 최근의 기술인 FRI (Finite Rate of Innovation) 개념과 LIMS (Least-squares based Iterative Multipath Super-resolution)기술의 적용사례를 소개한다. 결론으로는 이러한 새로운 기술들이 지구물리 탐사분야에 어떻게 활용될 수 있는지 논의한다.

아날로그 뇌파기를 응용한 간단한 디지털 뇌파 시스템 (Simple Digital EEG System Utilizing Analog EEG Machine)

  • 정기영;김재문;정만재
    • Annals of Clinical Neurophysiology
    • /
    • 제2권1호
    • /
    • pp.8-12
    • /
    • 2000
  • Purpose : The rapid development and wide popularity of Digital EEG(DEEG) is due to its convenience, accuracy and applicability for quantitative analysis. These advantages of DEEG make one hesitate to use analog EEG(AEEG). To assess the advantage of DEEG system utilizing AEEG(DAEEG) over conventional AEEG and the clinical applicability, a DAEEG system was developed and applied to animal model Methods : Sprague-Dawley rat as status epilepticus model were used for collecting the EEG data. After four epidural electrodes were inserted and connected to 8-channel analog EEG(Nihon-Kohden, Japan), continous. EEG monitoring via computer screen was done from two rats simultaneously. EEG signals through analog amplifier and filters were digitized at digital signal processor and stored in Windows-based pentium personal computer. Digital data were sampled at a rate of 200 Hz and 12 bit of resolution. Acquisition software was able to carry out 'real-time view, sensitivity control and event marking' during continuous EEG monitoring. Digital data were stored on hard disk and hacked-up on CD-ROM for off-line review. Review system consisted of off-line review, saving and printing out interesting segment and annotation function. Results: This DAEEG system could utilize most major functions of DEEG sufficiently while making a use of an AEEG. It was easy to monitor continuously compared to Conventional AEEG and to control sensitivity during ictal period. Marking the event such as a clinical seizure or drug injection was less favorable than AEEG due to slowed processing speed of digital processor and central processing unit. Reviewing EEG data was convenient, but paging speed was slow. Storage and management of data was handy and economical. Conclusion : Relatively simple digital EEG system utilizing AEEG can be set-up at n laboratory level. It may be possible to make an application for clinical purposes.

  • PDF

전국 농가의 읍.면 거주지역별 일반적 특성과 주거환경 비교 : 2008 농촌생활지표 자료를 중심으로 (General Characteristics and Housing Environments of Agricultural Households by Eup.Myun Area : Analyses of 2008 Survey Data on the Rural Living Indicators)

  • 조재순
    • 가정과삶의질연구
    • /
    • 제29권3호
    • /
    • pp.71-83
    • /
    • 2011
  • The purpose of this study was to find out the nationwide general characteristics and housing environments of agricultural households and the differences of them by Eup-Myun Areas. The data were subsample of the 2008 survey on the rural living indicators collected by the rural development administration. Only agricultural households, 73.7% of the original nationwide data (1,461 households out of 1,983) sampled by multi-stage stratified clustering methods and face to face interview in Aug. 2008, were selected and the cross-tabulation(X2) was mainly used to find the difference by Eup Myun areas through spss 12.0 for window. The results showed that the general characteristics of agricultural households such as head of household, family, and economic characteristics were mainly differed by Eup Myun Areas. Agricultural households in Eup area were more likely low in the general characteristics than were those in Myun area. Housing environments were less likely than the general characteristics differed by Eup Myun areas. Improvements of drinking water system, housing alteration, oder, and garbage system were needed to increase the satisfaction with residential environments of agricultural households. This study suggests the use of annual survey on the rural living indicators data would be applicable to various research subjects of home economics.

Optimal Offer Strategies for Energy Storage System Integrated Wind Power Producers in the Day-Ahead Energy and Regulation Markets

  • Son, Seungwoo;Han, Sini;Roh, Jae Hyung;Lee, Duehee
    • Journal of Electrical Engineering and Technology
    • /
    • 제13권6호
    • /
    • pp.2236-2244
    • /
    • 2018
  • We make optimal consecutive offer curves for an energy storage system (ESS) integrated wind power producer (WPP) in the co-optimized day-ahead energy and regulation markets. We build the offer curves by solving multi-stage stochastic optimization (MSSO) problems based on the scenarios of pairs consisting of real-time price and wind power forecasts through the progressive hedging method (PHM). We also use the rolling horizon method (RHM) to build the consecutive offer curves for several hours in chronological order. We test the profitability of the offer curves by using the data sampled from the Iberian Peninsula. We show that the offer curves obtained by solving MSSO problems with the PHM and RHM have a higher profitability than offer curves obtained by solving deterministic problems.

Digital Redesign of Gust Load Alleviation System using Control Surface

  • Tak, Hyo-Sung;Ha, Cheol-Keun;Lee, Sang-Wook;Kim, Tae-Uk;Hwang, In-Hee
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2005년도 ICCAS
    • /
    • pp.675-679
    • /
    • 2005
  • This paper deals with the problem of gust load alleviation in active control for the case that aeroelasticity takes place due to interaction between wing structure and aerodynamics on wing when aircraft meets gust during flight. Aeroservoelasticity model includes wing structure modeled in FEM, unsteady aerodynamics in minimum state approximate method, and models of actuator and sensors in state space. Based on this augmented model, digitally redesigned gust load alleviation system is designed in sampled-data control technique. From numerical simulation, this digital control system is effective to gust load on aircraft wing, which is shown in transient responses and PSD analysis to random gust inputs.

  • PDF

Periodic Sampled-Data Control for Fuzzy Systems;Intelligent Digital Redesign Approach

  • Kim, D.W.;Joo, Y.H.;Park, J.B.
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2005년도 ICCAS
    • /
    • pp.1492-1495
    • /
    • 2005
  • This paper presents a new linear-matrix-inequality-based intelligent digital redesign (LMI-based IDR) technique to match the states of the analog and the digital T-S fuzzy control systems at the intersampling instants as well as the sampling ones. The main features of the proposed technique are: 1) the affine control scheme is employed to increase the degree of freedom; 2) the fuzzy-model-based periodic control is employed; and the control input is changed n times during one sampling period; 3) The proposed IDR technique is based on the approximately discretized version of the T-S fuzzy system; but its discretization error vanishes as n approaches the infinity. 4) some sufficient conditions involved in the state matching and the stability of the closed-loop discrete-time system can be formulated in the LMIs format.

  • PDF

LMI-Based Intelligent Digital Redesign for Multirate Sampled-Data Fuzzy Systems

  • 김도완;주영훈;박진배
    • 한국지능시스템학회논문지
    • /
    • 제16권1호
    • /
    • pp.113-118
    • /
    • 2006
  • This paper presents a new linear-matrix-inequality-based intelligent digital redesign (LMI-based IDR) technique to match the states of the analog and the digital T-S fuzzy control systems at the intersampling instants as well as the sampling ones. The main features of the proposed technique are: 1) the affine control scheme is employed to increase the degree of freedom; 2) the fuzzy-model-based periodic control is employed, and the control input is changed n times during one sampling period; 3) The proposed IDR technique is based on the approximately discretized version of the T-S fuzzy system, but its discretization error vanishes as n approaches the infinity. 4) some sufficient conditions involved in the state matching and the stability of the closed-loop discrete-time system can be formulated in the LMIs format.

Robust Discretization of LTI Systems with Polytopic Uncertainties and Aperiodic Sampling

  • Lee, Dong Hwan;Park, Jin Bae;Joo, Young Hoon
    • Journal of Electrical Engineering and Technology
    • /
    • 제10권3호
    • /
    • pp.1255-1263
    • /
    • 2015
  • In the previous work, the authors studied the problem of robust discretization of linear time-invariant systems with polytopic uncertainties, where linear matrix inequality (LMI) conditions were developed to find an approximate discrete-time (DT) model of a continuous-time (CT) system with uncertainties in polytopic domain. The system matrices of obtained DT model preserved the polytopic structures of the original CT system. In this paper, we extend the previous approach to solve the problem of robust discretization of polytopic uncertain systems with aperiodic sampling. In contrast with the previous work, the sampling period is assumed to be unknown, time-varying, but contained within a known interval. The solution procedures are presented in terms of unidimensional optimizations subject to LMI constraints which are numerically tractable via LMI solvers. Finally, an example is given to show the validity of the proposed techniques.

교류 발전기의 고장 검출 알고리즘에 관한 비교 연구 (A Comparative Study on Fault Detection Algorithm of AC Generator)

  • 박철원;신광철;신명철
    • 전기학회논문지P
    • /
    • 제57권2호
    • /
    • pp.102-108
    • /
    • 2008
  • AC generator plays an important role of power system. The large AC generator fault may lead to large impacts or perturbations in power system. And then the protection of a generator has very important role in maintaining stability in a power system. In present, the DFT(discrete Fourier transform) based RDR(ratio differential relay) had been widely applied to a internal fault of a generator stator winding. But DFT has a serious drawback. In the course of transforming a target signal to frequency domain, time information is lost. DWT uses a time-scale region. This paper proposes an advanced fault detection algorithm using DWT(discrete Wavelet transform) to enhance the drawback of conventional DFT based relaying. To evaluate the performance of the proposed relaying, we used the test data which were sampled with 720 [Hz] per cycle and obtained from ATP(alternative transient program) simulation. And we made a comparative study of conventional DFT based RDR and the proposed relaying.