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Parameter Estimation of Single and Decentralized Control Systems Using Pulse Response Data

  • Cheres, Eduard;Podshivalov, Lev
    • Bulletin of the Korean Chemical Society
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    • v.24 no.3
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    • pp.279-284
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    • 2003
  • The One Pass Method (OPM) previously presented for the identification of single input single output systems is used to estimate the parameters of a Decentralized Control System (DCS). The OPM is a linear and therefore a simple estimation method. All of the calculations are performed in one pass, and no initial parameter guess, iteration, or powerful search methods are required. These features are of interest especially when the parameters of multi input-output model are estimated. The benefits of the OPM are revealed by comparing its results against those of two recently published methods based on pulse testing. The comparison is performed using two databases from the literature. These databases include single and multi input-output process transfer functions and relevant disturbances. The closed loop responses of these processes are roughly captured by the previous methods, whereas the OPM gives much more accurate results. If the parameters of a DCS are estimated, the OPM yields the same results in multi or single structure implementation. This is a novel feature, which indicates that the OPM is a convenient and practice method for the parameter estimation of multivariable DCSs.

Pediatric dual-energy X-ray absorptiometry: interpretation and clinical and research application

  • Lim, Jung Sub
    • Clinical and Experimental Pediatrics
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    • v.53 no.3
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    • pp.286-293
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    • 2010
  • Peak bone mass is established predominately during childhood and adolescence. It is an important determinant of future resistance to osteoporosis and fractures to gain bone mass during growth. The issue of low bone density in children and adolescents has recently attracted much attention and the use of pediatric dual-energy X-ray absorptiometry (DXA) is increasing. The process of interpretation of pediatric DXA results is different from that of adults because normal bone mineral density (BMD) of children varies by age, body size, pubertal stage, skeletal maturation, sex, and ethnicity. Thus, an appropriate normal BMD Z-score reference value with Z-score should be used to detect and manage low BMD. Z-scores below -2.0 are generally considered a low BMD to pediatrician even though diagnoses of osteoporosis in children and adolescents are usually only made in the presence of at least one fragility fracture. This article will review the basic knowledge and practical guidelines on pediatric DXA based on the International Society for Clinical Densitometry (ISCD) Pediatric Official Positions. Also discussed are the characteristics of normal Korean children and adolescents with respect to BMD development. The objective of this review is to help pediatricians to understand when DXA will be useful and how to interpret pediatric DXA reports in the clinical practice for management of children with the potential to develop osteoporosis in adulthood.

A Fast Vector Quantization using Subregion-based Caches of Codeword Indexes (부영역 기반 코드워드 인덱스 캐시를 사용한 고속 벡터 양자화)

  • Kim, Yong-Ha;Kim, Dae-Jin;Bang, Seung-Yang
    • Journal of KIISE:Software and Applications
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    • v.28 no.4
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    • pp.369-379
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    • 2001
  • 본 논문은 부영역 분할과 코드워드 인텍스의 캐시 개념을 이용하여 벡터 양자화를 위한 고속코드북 생성 및 부호화 방법을 제안한다. 제안한 방법은 인접한 입력 벡터는 대개 코드북내 특정 코드워드에 의해 나타내어지는 국부성에 바탕을 두고 있다. 초기에 모든 학습 벡터가 거리에 기반한 근접성을 이용하여 정해진 수의 부영역으로 분할된다. 각 부영역에 하나의 코드워드 인덱스 캐시가 할당되는데 이 캐시는 학습 초기에는 전체 코드북 크기에 대응하는 코드워드 인덱스를 갖는다. 학습이 진행되면서 입력 벡터가 갖는 국부성 때문에 각 부영역내 캐시중 사용되지 않는 코드워드 인덱스가 점차 발생하게 되므로 이들은 LRU(Least Recently Used) 삭제 알고리즘에 의해 제거된다. 학습이 진행됨에 따라 부영역 캐시에는 주어진 입력 벡터에 의해 참조되는 코드워드 인덱스만이 남게 되므로 한 학습 주기 동한 필요한 학습 시간이 점차 짧아지게 되어 전체적으로 코드북 생성 시간을 크게 줄일 수 있게 된다. 제안한 방법은 매 학습주기마다, 코드워드 인덱스 삭제 후보 중 주어진 부영역 중심으로부터 거리에 의해 멀리 떨어진 것부터 반만을 제거함에 따라. 복원된 영상의 화질 열화가 거의 없다. 시뮬레이션 결과 제안한 방법은 기존의 LBG 방법에 비해 화질 열화는 거의 없지만 코드북 생성 (또는 부호화) 속도를 2.6-5.4배 (또는3.7-18.8배) 향상시킨다.

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A Non-volatile Memory Lifetime Extension Scheme Based on the AUTOSAR Platform using Complex Device Driver (AUTOSAR 플랫폼 기반 CDD를 활용한 비휘발성 메모리 수명 연장 기법)

  • Shin, Ju-Seok;Son, Jeong-Ho;Lee, Eun-Ryung;Oh, Se-Jin;Ahn, Kwang-Seon
    • IEMEK Journal of Embedded Systems and Applications
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    • v.8 no.5
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    • pp.235-242
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    • 2013
  • Recently, the number of automotive electrical and electronic system has been increased because the requirements for the convenience and safety of the drivers and passengers are raised. In most cases, the data for controlling the various sensors and automotive electrical and electronic system used in runtime should be stored on the internal or external non-volatile memory of the ECU(Electronic Control Units). However, the non-volatile memory has a constraint with write limitation due to the hardware characteristics. The limitation causes fatal accidents or unexpected results if the non-volatile memory is not managed. In this paper, we propose a management scheme for using non-volatile memory to prolong the writing times based on AUTOSAR(AUTOmotive Open System Architecture) platform. Our proposal is implemented on the CDD(Complex Device Driver) and uses an algorithm which swaps a frequently modified block for a least modified block. Through the development of the prototype, the proposed scheme extends the lifetime of non-volatile memory about 1.08 to 2.48 times than simply using the AUTOSAR standard.

An Evaluation of the Second-order Approximation Method for Engineering Optimization (최적설계시 이차근사법의 수치성능 평가에 관한 연구)

  • 박영선;박경진;이완익
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.2
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    • pp.236-247
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    • 1992
  • Optimization has been developed to minimize the cost function while satisfying constraints. Nonlinear Programming method is used as a tool for the optimization. Usually, cost and constraint function calculations are required in the engineering applications, but those calculations are extremely expensive. Especially, the function and sensitivity analyses cause a bottleneck in structural optimization which utilizes the Finite Element Method. Also, when the functions are quite noisy, the informations do not carry out proper role in the optimization process. An algorithm called "Second-order Approximation Method" has been proposed to overcome the difficulties recently. The cost and constraint functions are approximated by the second-order Taylor series expansion on a nominal points in the algorithm. An optimal design problem is defined with the approximated functions and the approximated problem is solved by a nonlinear programming numerical algorithm. The solution is included in a candidate point set which is evaluated for a new nominal point. Since the functions are approximated only by the function values, sensitivity informations are not needed. One-dimensional line search is unnecessary due to the fact that the nonlinear algorithm handles the approximated functions. In this research, the method is analyzed and the performance is evaluated. Several mathematical problems are created and some standard engineering problems are selected for the evaluation. Through numerical results, applicabilities of the algorithm to large scale and complex problems are presented.presented.

Article Data Prefetching Policy using User Access Patterns in News-On-demand System (주문형 전자신문 시스템에서 사용자 접근패턴을 이용한 기사 프리패칭 기법)

  • Kim, Yeong-Ju;Choe, Tae-Uk
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.5
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    • pp.1189-1202
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    • 1999
  • As compared with VOD data, NOD article data has the following characteristics: it is created at any time, has a short life cycle, is selected as not one article but several articles by a user, and has high access locality in time. Because of these intrinsic features, user access patterns of NOD article data are different from those of VOD. Thus, building NOD system using the existing techniques of VOD system leads to poor performance. In this paper, we analysis the log file of a currently running electronic newspaper, show that the popularity distribution of NOD articles is different from Zipf distribution of VOD data, and suggest a new popularity model of NOD article data MS-Zipf(Multi-Selection Zipf) distribution and its approximate solution. Also we present a life cycle model of NOD article data, which shows changes of popularity over time. Using this life cycle model, we develop LLBF (Largest Life-cycle Based Frequency) prefetching algorithm and analysis he performance by simulation. The developed LLBF algorithm supports the similar level in hit-ratio to the other prefetching algorithms such as LRU(Least Recently Used) etc, while decreasing the number of data replacement in article prefetching and reducing the overhead of the prefetching in system performance. Using the accurate user access patterns of NOD article data, we could analysis correctly the performance of NOD server system and develop the efficient policies in the implementation of NOD server system.

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Identification of Closed Loop System by Subspace Method (부분공간법에 의한 페루프 시스템의 동정)

  • Lee, Dong-Cheol;Bae, Jong-Il;Hong, Soon-Il;Kim, Jong-Kyung;Jo, Bong-Kwan
    • Proceedings of the KIEE Conference
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    • 2003.07d
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    • pp.2143-2145
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    • 2003
  • In the linear system identification using the discrete time constant coefficients, there is a subspace method based on 4SID recently much suggested instead of the parametric method like as the maximum likelihood method. The subspace method is not related with the impulse response and difference equation in its input-output equation, but with the system matrix of the direct state space model from the input-output data. The subspace method is a very useful tool to adopt in the multivariable system identification, but it has a shortage unable to adopt in the closed-loop system identification. In this paper, we are suggested the methods to get rid of the shortage of the subspace method in the closed-loop system identification. The subspace method is used in the estimate of the output prediction values from the estimating of the state space vector. And we have compared the results with the outputs of the recursive least square method in the numerical simulation.

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Forensic Evaluation of Prostate-Specific-Antigen (PSA) Rapid Test Kit for Identification of Human Semen (전립선특이항원검사 Kit에 의한 정액의 신속 검출법)

  • Lim, Chae-Won;Lee, Jong-Hoon;Kim, Hyung-Lak
    • Korean Journal of Clinical Laboratory Science
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    • v.41 no.2
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    • pp.76-82
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    • 2009
  • It would be one of the most important tests that determination of semen in crime scene as a matter of significant evidences. Recently, it has been developed for the identification of semen in forensic specimens which was used simply, easily and reproductively. In this study, Prostate-Specific-Antigen (PSA) Rapid Test kit was evaluated for the forensic identification of semen and compared with one step semen inspection forensic rapid test kit. The sensitivity and specificity of the rapid PSA kit were examined in addition to the stability of PSA. The positive band of rapid PSA kit shown even with 1,000,000-fold diluted semen, which was at least 100 timed higher than qualitative one step semen inspection forensic rapid test kit. PSA was detected in urine from normal male adult, however, it was not detected in urine from young boys and female body fluids. It was shown that PSA was very stable to resist boiling for 20 minutes and the effect of bacteria. In crime scene investigation, rapid PSA kit is expected to help to identify semen easily in the evidences.

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HHT method for system identification and damage detection: an experimental study

  • Zhou, Lily L.;Yan, Gang
    • Smart Structures and Systems
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    • v.2 no.2
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    • pp.141-154
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    • 2006
  • Recently, the Hilbert-Huang transform (HHT) has gained considerable attention as a novel technique of signal processing, which shows promise for the system identification and damage detection of structures. This study investigates the effectiveness and accuracy of the HHT method for the system identification and damage detection of structures through a series of experiments. A multi-degree-of-freedom (MDOF) structural model has been constructed with modular members, and the columns of the model can be replaced or removed to simulate damages at different locations with different severities. The measured response data of the structure due to an impulse loading is first decomposed into modal responses using the empirical mode decomposition (EMD) approach with a band-pass filter technique. Then, the Hilbert transform is subsequently applied to each modal response to obtain the instantaneous amplitude and phase angle time histories. A linear least-square fit procedure is used to identify the natural frequencies and damping ratios from the instantaneous amplitude and phase angle for each modal response. When the responses at all degrees of freedom are measured, the mode shape and the physical mass, damping and stiffness matrices of the structure can be determined. Based on a comparison of the stiffness of each story unit prior to and after the damage, the damage locations and severities can be identified. Experimental results demonstrate that the HHT method yields quite accurate results for engineering applications, providing a promising tool for structural health monitoring.

Chronic administration of ketamine ameliorates the anxiety- and aggressive-like behavior in adolescent mice induced by neonatal maternal separation

  • Shin, Sang Yep;Baek, Nam Jun;Han, Seung Ho;Min, Sun Seek
    • The Korean Journal of Physiology and Pharmacology
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    • v.23 no.1
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    • pp.81-87
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    • 2019
  • Ketamine has long been used as an anesthetic agent. However, ketamine use is associated with numerous side effects, including flashbacks, amnesia, delirium, and aggressive or violent behavior. Ketamine has also been abused as a cocktail with ecstasy, cocaine, and methamphetamine. Several studies have investigated therapeutic applications of ketamine, demonstrating its antidepressant and anxiolytic effects in both humans and rodents. We recently reported that neonatal maternal separation causes enhanced anxiety- and aggressive-like behaviors in adolescent. In the present study, we evaluated how acute and chronic ketamine administration affected the behavioral consequences of neonatal maternal separation in adolescent mice. Litters were separated from dams for 4 hours per day for 19 days beginning after weaning. Upon reaching adolescence (post-natal day 35-49), mice were acutely (single injection) or chronically (7 daily injections) treated with a sub-anesthetic dose (15 mg/kg) of ketamine. At least 1 h after administration of ketamine, mice were subjected to open-field, elevated-plus maze, and resident-intruder tests. We found that acute ketamine treatment reduced locomotor activity. In contrast, chronic ketamine treatment decreased anxiety, as evidenced by increased time spent on open arms in the elevated-plus maze, and remarkably reduced the number and duration of attacks. In conclusion, the present study suggests that ketamine has potential for the treatment of anxiety and aggressive or violent behaviors.