• Title/Summary/Keyword: PSV

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Development of Attenuation Equations of Ground Motions in the Southern Part of the Korean Peninsula (한반도 남부 지역의 지진동 감쇄식 개발)

  • 이기화
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.04a
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    • pp.39-43
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    • 1998
  • The objective of the study is to develop attenuation equations of groud motions in the southern part of the Korean Peninsula. The earthquake source characteristics and the medium properties were estimated from available instrumental earthquake records and used as input parameters. The peak ground accelerations (PGA) and pseudo-velocty response spectra(PSV) were simulated by the random vibration theory. The attenuation equations for the PGA were constructed in terms of local magnitudes and hypocentral distances.

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A study on characteristics of the autonomic nervous system in students with Keongke - Using Heart Rate Variability and Pupil Size Variability - (경계(驚悸) 증상을 지닌 학생 집단의 자율 신경 기능 특성에 대한 연구 - 심박변이도와 동공크기 변이도를 중심으로 -)

  • Lee, Seung-Gi;Lee, Jeong-Chan;Kim, Ji-Eun;Park, Kyung-Mo;Kang, Hee-Chul
    • Journal of Oriental Neuropsychiatry
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    • v.17 no.2
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    • pp.133-145
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    • 2006
  • Objective : The purpose of this experimental-controlled study was to investigate the characteristics of the autonomic nervous system in students with Keongke by using HRV(Heart rate variability) and PSV(Pupil size variability). Method : The study group was consisted of 11 students with self recognition as the experimental group, and 25 normal students as the control group. Informations on gender and age were obtained by medical charts and personal interviews. By using heart rate variability and pupil size variability, we measured the value of HRT(Heart rate), SDNN(Standard deviation of NN intervals), LFnorm(Low frequency normalization), HFnorm(High frequency normalization), LF/HF ratio, Pupil area, B.S.(Basic size), C.R.(Max Constriction Rate) and 1s.d.(1sec Dilation Rate). I compared the degrees of the sympathetic and parasympathetic activity. Result : 1. In the result of heart rate variability between experimental and control group, none of the parameters of experimental group were significantly different from control group. And even though there were no statistical significance, there were some numerical differences in SDNN, LF norm, HF norm. 2. In pupil size variability, C.R. and 1s.d. of the experimental group were increased compared to control group. Conclusion : The study results suggest that the group with Keongke has differences of autonomic nervous system as compared to those in normal state. Measurement value of PSV is a new technical approach to estimate the autonomic nervous system.

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Molecular characterization of Cucumber mosaic virus isolates isolated in Korea

  • Park, Jang-Kyung
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.4-8
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    • 2003
  • Cucumber mosaic virus (CMV) belongs to genus Cucumovirus. The Cucumovirus group contains three distinct members: CMV, Tomato aspermy virus (TAV), and Peanut stunt virus (PSV). The type member, CMV is the most widespread and most studied. CMV is isometric particles about 30 nm in diameter. The genome of CMV is divided into three RNAs. In addition, RNA extracted from virus particles contains a fourth RNA that is a subgenomic RNA generated from RNA3. RNA1 and RNA2 are each encapsidated in separate particles, whereas RNAs3 and 4 are coencapsidated in a third particle. Hence, inoculation by three particles, transmitted either mechanically or by the aphid vector, is required to infect plants.(중략)

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A Study on the analysis of in-cylinder flow fields using PTV (PTV를 이용한 실린더내 유동장 해석에 관한 연구)

  • Jeong, Hwan-Su;Choi, Su-Jin;Jeon, Chung-Hwan;Chang, Young-June
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.692-697
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    • 2000
  • In Particle Tracking Velocimetry, the analysis of double-exposed photographic plate can be carried out either by means of Young's fringe analysis or by a digital image processing technique. In this study, we used digital image processing to two images in one frame far analyzing in-cylinder flow fields, and compared PTV with PSV(Particle Streak Velocimetry). Additionally, this technique was verified by two different calibration method. One is interpolation by invert distance, the other is interpolation by area ratio. Finally, the results between two interpolation methods were similar in whole flow fields.

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Reliability Analysis on Safety Instrumented System by Using Safety Integrity Level for Fire.Explosion Prevention in the Ethyl Benzene Processes (Ethyl Benzene 공정에서 화재.폭발방지를 위하여 안전건전성수준을 이용한 안전장치시스템의 신뢰도 분석)

  • Ko, Jae-Sun;Kim, Hyo;Lee, Su-Kyoung
    • Fire Science and Engineering
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    • v.20 no.3 s.63
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    • pp.1-8
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    • 2006
  • The purpose of this work is to analyze quantitatively if the safety instrumented system(SIS) like the pressure safety valves(PSV) in the processes of ethyl benzene plant have been designed relevantly to the safety integrity level because overpressure in the benzene or ethyl benzene columns causes the explosive reactions, fires and reactor explosions. The safety integrity level(SIL) 3 has been adopted as a target level of SIS based on the general data of the Probability of Failure on Demand of PSV, $1.00E-4{\sim}1.00E-3$. The standard model of the reliability has been set up and then the fault tree analysis of it has been carried out to get the PFD of SIS, and the results show 8.97E-04, 5.37E-04, 5.37E-04 for benzene prefractionator column, benzene column and EB column, respectively. Thus, we conclude that the SIS is designed to fulfill the condition of SIL3, and when the partial stroke test for the control valve are carried out every sixth month, the SIS of each column is expected to increase its reliability up to $22{\sim}27%$.

Possible Causes of Paleosecular Variation and Deflection of Geomagnetic Directions Recorded by Lava Flows on the Island of Hawaii

  • Czango Baag
    • Proceedings of the International Union of Geodesy And Geophysics Korea Journal of Geophysical Research Conference
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    • 2003.05a
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    • pp.20-20
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    • 2003
  • In the summers of 1997 and 1998 and in February of 2000 we made 570 measurements of the ambient geomagnetic field 120 cm above the pavement surface of State Route 130, south of Pahoa, the island of Hawaii using a three-component fluxgate magnetometer. We measured at every 15.2 m (50 feet) interval covering a distance of 6, 310 m (20, 704 ft) where both historic and pre-historic highly magnetic basalt flows underlie. We also collected 197 core samples from eight road cuts, 489 specimens of which were subject to AF demagnetizations at 5 - 10 mT level up to a maximum field of 60 mT. We observed significant inclination anomalies ranging from a minimum of $31^{\circ}$ to a maximum $40^{\circ}$ where a uniform inclination value of $36.7^{\circ}$ (International Geomagnetic Reference Field, IGRF) was expected. Since the mean of the observed inclinations is approximately $35^{\circ}$ we assume that the study area is slightly affected by the magnetic terrain effect to a systematically shallower inclinations for being located in the regionally sloping surface of the southern side of the island (Baag, et al., 1995). We observed inclination anomalies showing wider (spacial) wavelength (160 - 600 m) and higher amplitudes in the historic lava flows area than in the northern pre-historic flows. Our observations imply that preexisting inclination anomalies such as those that we observed would have been interpreted as paleosecular variation (PSV). These inclination anomalies can best be attributed to concealed underground highly magnetic dikes, channel type lava flows, on-and-off hydrothermal activities through fissure-like openings, etc. Both the within- and between-site dispersions of natural remanent magnetization (NRM) are largest (up to ${\pm}7^{\circ}$) above the flows of 1955, while the area of pre-historic flows in the northern part of the study area exhibit the smallest dispersion. Nevertheless, mean inclinations of each historic flow of 1955 and 1790 are almost identical to that of the corresponding present field, whereas mean of NRM (after AF demagnetization) inclinations for each of the four pre-historic lava flow units is twelve to thirteen degrees lower than the present field inclination. We observed three cases of very large inclination variations from within a single flow, the best fitting curves of which are linear, second and third order polynomials each from within a single flow, whereas no present field variations are observed. This phenomena can be attributed to the notion that local magnetic anomalies on the surface of an active volcano are not permanent, but are transient. Therefore we believe that local magnetic anomalies of an active volcano may be constantly modified due to on going subsurface injections and circulations of hot material and also due to wide spacial and temporal distribution of highly magnetic basaltic flows that will constantly modify the topography which will in turn modify the local ambient geomagnetic field (Baag, et al., 1995). Our observations bring into question the general reliability of PSV data inferred from volcanic rocks, because on-going various geologic and geophysical activities associated with active volcano would continuously deflect and modify the ambient geomagnetic field.

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Trajectory Control of Excavator Actuators Using IMV (IMV를 이용한 굴착기 작업장치 궤적제어)

  • Jung, Gyuhong
    • Journal of Drive and Control
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    • v.17 no.2
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    • pp.45-54
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    • 2020
  • The IMV is a combination of four two-way valve systems which replace a conventional four-way spool valve to improve efficiency mostly in excavator hydraulics. As the environmental regulations for construction equipment have tightened, some overseas advanced companies have released commercial excavators in which the MCV is implemented with the IMVs. Development of the IMV type MCV relies on the control algorithm as well as the robust performance of proportional flow control valves. In this study, the IMV controller was designed and verified with experiments for the excavator working unit, which determines the IMV mode of operation and the extent of the valve opening in consideration of the load conditions on hydraulic actuators. First, the open-loop controller was designed with a joystick command vs. a PSV reference current map comprising several control parameters in to compensate for the different flow characteristics and non-linearities of two-way flow control valves. Second, the closed-loop controller was designed with the PI control fed by the actuator displacement and outputs actuator percent effort equivalent to the operator's joystick command. Finally, the performance of the IMV type MCV was verified with the trajectory control of position references derived from the energy consumption test standard. Experimental results showed the control performance of the IMV developed in this study, and suggest that future studies to be conducted to advance technical progress.

FLB Event Analysis with regard to the Fuel Failure

  • Baek, Seung-Su;Lee, Byung-Il;Lee, Gyu-Cheon;Kim, Hee-Cheol;Lee, Sang-Keun
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05b
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    • pp.622-627
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    • 1996
  • Detailed analysis of Feedwater Line Break (FLB) event for the fuel failure point of view are lack because the event was characterized as the increase in reactor coolant system (RCS) pressure. Up to now, the potential of the rapid system heatup case has been emphasized and comprehensively studied. The cooldown effects of FLB event is considered to be bounded by the Steam Line Break (SLB) event since the cooldown effect of SLB event is larger than that of the FLB event. This analysis provides a new possible path which can cause the fuel failure. The new path means that the fuel failure can occur under the heatup scenario because the Pressurizer Safety Valves (PSVs) open before the reactor trips. The 1000 MWe typical C-E plant FLB event assuming Loss of Offsite Power (LOOP) at the turbine trip has been analyzed as an example and the results show less than 1% of the fuel failure. The result is well within the acceptance criteria. In addition to that, a study was accomplished to prevent the fuel failure for the heatup scenario case as an example. It is found that giving the proper pressure gap between High Pressurizer Pressure Trip (HPPT) analysis setpoint and the minimum PSV opening pressure could prevent the fuel failure.

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A Large-Scale 3D Visualization System for Port Container Terminal Simulation (항만 컨테이너 시뮬레이션을 위한 대규모 3D 가시화 시스템 개발)

  • Ok, Soo-Yol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.1
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    • pp.119-126
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    • 2015
  • In this paper, we propose a 3D visualization system that expresses the simulation results of port container operation monitoring and planning in terms of the movements of the surrounding environment including static and dynamic objects. It also enables us to objectively evaluate the operation model by way of animating the actual port operations. With XML-based design of object states, the port simulator visualization system (PSVS) that we propose has been implemented so as to maximize the interoperability with the existing port operation simulation (CATOS), and express the realtime animation of large-scale objects. The design method of PSVS system is explained, and its validity is experimentally examined.

A study on determination of target displacement of RC frames using PSV spectrum and energy-balance concept

  • Ucar, Taner;Merter, Onur;Duzgun, Mustafa
    • Structural Engineering and Mechanics
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    • v.41 no.6
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    • pp.759-773
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    • 2012
  • The objective of this paper is to present an energy-based method for calculating target displacement of RC structures. The method, which uses the Newmark-Hall pseudo-velocity spectrum, is called the "Pseudo-velocity Spectrum (PSVS) Method". The method is based on the energy balance concept that uses the equality of energy demand and energy capacity of the structure. First, nonlinear static analyses are performed for five, eight and ten-story RC frame structures and pushover curves are obtained. Then the pushover curves are converted to energy capacity diagrams. Seven strong ground motions that were recorded at different soil sites in Turkey are used to obtain the pseudo-acceleration and the pseudo-velocity response spectra. Later, the response spectra are idealised with the Newmark-Hall approximation. Afterwards, energy demands for the RC structures are calculated using the idealised pseudo-velocity spectrum. The displacements, obtained from the energy capacity diagrams that fit to the energy demand values of the RC structures, are accepted as the energy-based performance point of the structures. Consequently, the target displacement values determined from the PSVS Method are checked using the displacement-based successive approach in the Turkish Seismic Design Code. The results show that the target displacements of RC frame structures obtained from the PSVS Method are very close to the values calculated by the approach given in the Turkish Seismic Design Code.