• Title/Summary/Keyword: transient period

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Analysis of Transient Features in Speech Signal by Estimating the Short-term Energy and Inflection points (변곡점 및 단구간 에너지평가에 의한 음성의 천이구간 특징분석)

  • Choi, I.H.;Jang, S.K.;Cha, T.H.;Choi, U.S.;Kim, C.S.
    • Speech Sciences
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    • v.3
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    • pp.156-166
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    • 1998
  • In this paper, I would like to propose a dividing method by estimating the inflection points and the average magnitude energy in speech signals. The method proposed in this paper gave not only a satisfactory solution for the problems on dividing method by zero-crossing rate, but could estimate the feature of the transient period after dividing the starting point and transient period in speech signals before steady state. In the results of the experiment carried out with monosyllabic speech, it was found that even through speech samples indicated in D.C. level, the staring and ending point of the speech signals were exactly divided by the method. In addition to the results, I could compare with the features, such as the length of transient period, the short term energy, the frequency characteristics, in each speech signal.

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Neonatal skin diseases (신생아 피부질환)

  • Kim, Kyu Han
    • Clinical and Experimental Pediatrics
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    • v.49 no.1
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    • pp.1-5
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    • 2006
  • Several physiological skin changes such as vernix caseosa, cutis marmorata, physiologic desquamation, and sebaceous hyperplasia have been described in the neonatal period. There are also clinical characteristics of skin peculiar to neonate and infancy. Skin disorders observed during neonatal and infancy period can be divided into transient skin lesions, birth marks, and other diseases. Transient skin lesions include milia, sebaceous gland hyperplasia, erythema neonatorum, transient neonatal pustular melanosis, and acne neonatorum. Nevocellular nevus, mongolian spot, vascular malformation, hemangioma, epidermal nevus, and sebaceous nevus belong to birth marks. There are several common skin diseases such as miliaria, diaper dermatitis, atopic dermatitis, seborrheic dermatitis, and cutaneous candidiasis.

A Study on Initial Transient Behavior in Creep-Fatigue Crack Growth (크리프-피로 균열성장에서의 초기 천이거동에 대한 연구)

  • 백운봉;남승훈;윤기봉
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.7
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    • pp.1722-1729
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    • 1994
  • At early stage of creep-fatigue crack growth tests, initial transient behavior which implies high crack growth rate has been generally observed by some researchers. Since the influence of the initial transient crack growth behavior on the remaining life of components is significant, cause of it should be further studied. In this study, characteristics of the initial transient behavior of 1Cr-1Mo-0.25V steel is studied experimentally by performing creep-fatigue crack growth tests at $538^{\circ}C$ in air under trapezoidal waveshapes. It is verified that the cause of the initial transient behavior is not high ${(C_t)}_{avg}$ values due to the small scale creep condition at the early stage of test, but oxidation-dominated crack growth mechanism during the transient period which is different from the creep-dominated crack growth mechanism in steady crack growth period.

On the extended period of a frequency domain method to analyze transient responses

  • Chen, Kui Fu;Zhang, Qiang;Zhang, Sen Wen
    • Structural Engineering and Mechanics
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    • v.31 no.2
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    • pp.211-223
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    • 2009
  • Transient response analysis can be conducted either in the time domain, or via the frequency domain. Sometimes a frequency domain method (FDM) has advantages over a time domain method. A practical issue in the FDM is to find out an appropriate extended period, which may be affected by several factors, such as the excitation duration, the system damping, the artificial damping, the period of interest, etc. In this report, the extended period of the FDM based on the Duhamel's integral is investigated. This Duhamel's integral based FDM does not involve the unit impulse response function (UIRF) beyond the period of interest. Due to this fact, the ever-lasting UIRF can be simply set as zero beyond the period of interest to shorten the extended period. As a result, the preferred extended period is the summation of the period of interest and the excitation duration. This conclusion is validated by numerical examples. If the extended period is too short, then the front portion of the period of interest is more prone to errors than the rear portion, but the free vibration segment is free of the wraparound error.

Recurrent transient amnesia: a case of transient epileptic amnesia misdiagnosed as transient global amnesia

  • Kihoon Shin;Ki-Hwan Ji
    • Annals of Clinical Neurophysiology
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    • v.25 no.2
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    • pp.103-105
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    • 2023
  • Transient epileptic amnesia and transient global amnesia both exhibit temporary memory loss. The lack of clues of epileptic events and the absence of epileptiform abnormalities in electroencephalography, a clear brain lesion, and interictal cognitive decline can make diagnoses challenging. Here we present a middle-aged female who experienced long-term recurrent transient epileptic amnesia with subtle epileptic features over a period of 3 years.

A Study on the Prediction of Temperature Change during the Thermal Fatigue Test of Exhaust Manifolds (배기계 내구시험 중의 온도 변화 예측을 위한 연구)

  • 이원근
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.5
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    • pp.29-36
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    • 2003
  • Exhaust manifolds suffer from serious temperature variation during the thermal fatigue test. The spatial distribution of temperature changes at each moment. Because transient flow can not be simulated during the long period of temperature change, the simulation can not be performed by conjugate heat transfer analysis. In this study, a new procedure for transient thermal analysis is established by decoupling fluid-solid analysis. The procedure consists of (1) transient CFD calculation (2 cycles), (2) mapping heat transfer coefficient to the inner surface of solid mesh as a boundary condition of heat conduction analysis and (3) transient heat conduction analysis in the long period (30 min). The realistic temperature change can be predicted by this procedure.

TRANSIENT CHF PHENOMENA DUE TO EXPONENTIALLY INCREASING HEAT INPUTS

  • Park, Jong-Doc;Fukuda, Katsuya;Liu, Qiusheng
    • Nuclear Engineering and Technology
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    • v.41 no.9
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    • pp.1205-1214
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    • 2009
  • The critical heat flux (CHF) levels that occurred due to exponential heat inputs for varying periods to a 1.0-mm diameter horizontal cylinder immersed in various liquids were measured to develop an extended database on the effect of high subcoolings for quasi-steady-state and transient maximum heat fluxes. Two main mechanisms of CHF were found. One mechanism is due to the time lag of the hydrodynamic instability (HI) which starts at steady-state CHF upon fully developed nucleate boiling, and the other mechanism is due to the explosive process of heterogeneous spontaneous nucleation (HSN) which occurs at a certain HSN superheat in originally flooded cavities on the cylinder surface. Steady-state CHFs were divided into three regions for lower, intermediate and higher subcooling at pressures resulting from HI, transition and HSN, respectively. HSN consistently occurred in the transient boiling CHF conditions that correspond to a short period. It was also found that the transient boiling CHFs gradually increased, then rapidly decreased and finally increased again as the period became shorter.

Factors Influencing the Changes of BAEPs in Vertebrobasilar Transient Ischemic Attacks (추골기저동맥 일과성 허혈발작에서 뇌간청각유발전위변화에 영향을 미치는 인자)

  • Park, Young Hyuk;Yoo, Bong Goo;Kim, Kwang Soo;Yoo, Kyung Moo
    • Annals of Clinical Neurophysiology
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    • v.2 no.2
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    • pp.101-106
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    • 2000
  • Background and Purpose : Brainstem auditory evoked potentials(BAEPs) are responses of the brainstem by auditory stimulation. Vertebrobasilar transient ischemic attacks is the disease that occurs by insufficient circulation in the region of brainstem. The purpose of this study is to know the factors influencing the changes of BAEPs in vertebrobasilar transient ischemic attacks. Methods : The subject of study was 96 patients diagnosed as vertebrobasilar transient ischemic attacks. Patients were divided into two groups according to the BAEPs findings. Their age, sex, presence of hypertension, diabetes, hyperlipidemia, heart disease, neurologic findings, previous stroke, previous vertebrobasilar transient ischemic attacks, smoking and alcohol drinking, and time period between symptom onset and testing were compared. Results : There were no significant differences in age, sex, and presence of hypertension, diabetes, hyperlipidemia, heart disease, previous stroke history, previous vertebrobasilar transient ischemic attack, smoking, and alcohol drinking between two groups. The presence of abnormal neurologic findings in the first examination and time period between symptom onset and testing were significantly different between normal BAEPs group and abnormal BAEPs one(P<0.05). Conclusions : The factors influencing the changes of BAEPs were presence of abnormal neurologic findings and time period between symptom onset and testing. These findings suggest that BAEPs test should be performed in acute stage of ischemic attack.

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Weighted fuzzy controller composed of position type fuzzy controller and velocity type fuzzy controller (위치형퍼지제어기와 속도형퍼지제어기로 구성된 퍼지 가중치 제어기)

  • 김병수;박준열
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.181-183
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    • 1996
  • Generally, While position type fuzzy controller has good performance in transient period, it has uniform steady state error of response. While velocity type fuzzy controller is capable of reducing steady state error of response, it is hard to develop the performance in transient period. In order to have both good performance in transient period and ability to reduce the steady state error of response, weighting fuzzy controller, which is composed of these two fuzzy controllers, is proposed. For the decision of weight to each fuzzy controller, Weighting fuzzy set is established according to the system state variables and applied to each fuzzy controller. The proposed weighted fuzzy controller has the merits of both position type fuzzy controller and velocity type fuzzy controller simultaneously.

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Analysis and Reduction of Transient Time Periods for Smooth Handoff Packets in Mobile IPv6 Networks (Mobile IPv6망에서 Smooth 핸드오프 패킷의 과도기간 분석 및 단축)

  • Lee, Dong-Wook;Kim, Jong-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.11B
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    • pp.999-1006
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    • 2003
  • In the paper, we investigate the impact of handoff on the packet delivery in the Mobile IPv6 networks, where the smooth handoff is adopted. That is measured by an 'unstable time period (UTP)', a 'silence time period(STP)', and a 'handoff time period (HTP)' in the mobile node's perspective. Then, we propose a queuing model to get the exact value of the handoff transient time. The numerical results show that the queuing delay for the handoff packets and the involved link (or route) capacities affect the estimated UTP, STP, and HTP. On the other hand, the damage of application caused by handoff will increases when the handoff transient time becomes longer. We show that the priority scheduling method can achieve shorter STP and UP than the FIFO scheduling method that is generally used in best-effort IP network.