• Nuclear Engineering and Technology
• /
• v.50 no.8
• /
• pp.1426-1432
• /
• 2018

This paper presents a neutron detector configuration using EJ-301 scintillation liquid, a R9420 photo-multiplier and a homemade preamplifier. The detector qualities which include the energy linearity, efficiency response and neutron/gamma discrimination are guaranteed for neutron detection in the energy range from 0 to 3000 keVee. Regarding the neutron/gamma discrimination capability, four pulse shape discrimination (PSD) methods which are the threshold crossing time (TCT), pulse gradient analysis (PGA), charge comparison (CC) and correlation pattern recognition (CPR), were evaluated and discussed; among of these, the CPR method provides the best neutron/gamma discrimination.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.39 no.6
• /
• pp.8-18
• /
• 2002

We study complicated nonlinear interactions of two orthogonally polarized pulses with pulse-width of less than 100fsec in the all-optical phase-shift switches, which use soliton pulse-train and fiber-splicing for control pulse to obtain multi-collisional $\pi$-phase-shift and consider Raman response function. We investigate switching performance in various input parameters such as input pulse-width and birefringence of fiber, and find optimum initial conditions for good switching performance in such all-optical switches.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.45 no.5
• /
• pp.21-27
• /
• 2008

Despite recent studies on development of pulse diagnosis systems and needs for commercializing them, the reproducibility is one of the most controversial issues as ever. Because the pulse pressure value, which is one of the important parameters to evaluate reproducibility, is very vulnerable to moving artifacts, the reproducibility can not be obtained easily. In this paper, we suggested a moving artefacts detection system for a pulse diagnosis system so that a pulse diagnosis system can be robust to theses kinds of artefacts by excluding the contaminated parts from the pulse wave signal to be analyzed. This moving artifacts detection system was designed to consist of a three-axis accelerometer, an electromyography amplifier and a two-axis tilt sensor. To assess the suitability of the system, we examined the characteristics of each sensor's output signals with regard to the three specific motions such as extension, flexion and rotation. And, we also examined the each sensor's response to the high-frequency and low-frequency moving artifacts while the pulse wave signal was acquired from a pressure sensor for the pulse diagnosis. From these results, we could find that the response to subject's motions would be reflected in electromyography signal first, in accelerometer signals and in tilt sensor sequently. And, the facts that a stable pulse wave can be acquired in two seconds after high frequency or low frequency motions ended, were also found. Consequently, based on these findings, we set up some rules on the moving artifacts detection and designed an algorithm which is fit for our moving artifacts detection system.

• Women's Health Nursing
• /
• v.6 no.4
• /
• pp.579-593
• /
• 2000

The purpose of this study was to examine the effects of foot massage on anxiety response in preoperative patients undergoing total hysterectomy. Among the fifty patients, twenty-five were the experimental group receiving foot massage for 10-minutes and twenty-five were the control group. Subjects were admitted to a hospital in Inchon city for total hysterectomy. This study was carried out from July 10th, to September 18th, 2000. The levels of anxiety were measured by the Visual Aanalogue Scale(VAS). State Anxiety Scale, blood pressure, pulse rate and respiration rate. Data were analyzed using $x^2$-test, t-test, paired t-test, unpaired t-test and ANCOVA with SPSS/pc program. The results were summarized as followings: 1. After foot massage, VAS anxiety level, state anxiety level, systolic blood pressure, pulse rate and respiration rate of the experimental group were decreased significantly than those measurements before the foot massage. 2. After foot massage, significant differences in the VAS anxiety level, state anxiety level, systolic blood pressure, pulse and respiration rate between the experimental and control groups were found. In conclusion, foot massage for 10 minutes is a useful nursing intervention that decreases anxiety in preoperative patients undergoing total hysterectomy.

• Structural Engineering and Mechanics
• /
• v.34 no.6
• /
• pp.755-778
• /
• 2010

Near-fault ground motion with directivity or fling effects is significantly influenced by the rupture mechanism and substantially different from ordinary records. This class of ground motion has large amplitude and long period, exhibits unusual response spectra shapes, possesses high PGV/PGA and PGD/PGA ratios and is best characterized in the velocity and the displacement time-histories. Such ground motion is also characterized by its energy being contained in a single or very few pulses, thus capable of causing severe damage to the structures. This paper investigates the characteristics of near-fault pulse-like ground motions and their implications on the structural responses using new proposed measures, such as, the effective frequency range, the energy rate (in time and frequency domains) and the damage indices. The paper develops also simple mathematical expressions for modeling this class of ground motion and the associated structural responses, thus eliminating numerical integration of the equations of motion. An optimization technique is also developed by using energy concepts and damage indices for modeling this class of ground motion for inelastic structures at sites having limited earthquake data.

• Bulletin of the Korean Chemical Society
• /
• v.24 no.7
• /
• pp.948-952
• /
• 2003

New approach for the determination of Ag(I) ion was performed by using a carbon paste electrode (CPE) containing N,N'-Diphenyl oxamide (DPO) with anodic stripping voltammetry. The CMEs have been prepared by making carbon paste mixtures containing an appropriate amount of DPO salt coated onto graphite particles to analyze trace metal ions via complexation followed by stripping voltammetry. Various experimental parameters affecting the response, such as pH, deposition time, temperature, and electrode composition, were carefully optimized. Using differential pulse anodic stripping voltammetry, the logarithmic linear response range for the Ag(I) ion was 1.0 × $10^{-7}$ - 5.0 × $10^{-9}$ M at the deposition time of 10 min, with the detection limit was 7.0 × $10^{-10}$ M. The detection limit adopted from anodic stripping differential pulse voltammetry was 7.0 × $10^{-10}$ M for silver and the relative standard deviation was ± 3.2% at a 5.0 × $10^{-8}$ M of Ag(I) ion (n = 7). The proposed electrode shows a very good selectivity for Ag(I) in a standard solution containing several metals at optimized conditions.

• Structural Engineering and Mechanics
• /
• v.75 no.6
• /
• pp.713-722
• /
• 2020

This article aims to illustrate the damped dynamic responses of layered functionally graded (FG) thick 2D beam under dynamic pulse sinusoidal load by using finite element method, for the first time. To investigate the response of thick beam accurately, two-dimensional plane stress problem is assumed to describe the constitutive behavior of thick beam structure. The material is distributed gradually through the thickness of each layer by generalized power law function. The Kelvin-Voigt viscoelastic constitutive model is exploited to include the material internal damping effect. The governing equations are obtained by using Lagrange's equations and solved by using finite element method with twelve -node 2D plane element. The dynamic equation of motion is solved numerically by Newmark implicit time integration procedure. Numerical studies are presented to illustrate stacking sequence and material gradation index on the displacement-time response of cantilever beam structure. It is found that, the number of waves increases by increasing the graduation distribution parameter. The presented mathematical model is useful in analysis and design of nuclear, marine, vehicle and aerospace structures those manufactured from functionally graded materials (FGM).

• Journal of Biomedical Engineering Research
• /
• v.3 no.2
• /
• pp.105-112
• /
• 1982

Using electronic cochlear implant system, we studied in cats the difference in the response of the brain stem evoked response (BER) during the stimulation with the acoustic signals and the electric signals. These brain stem electric responses were analyzed using the integral pulse frequency modulation method of the auditory nervous system. Animal experimental results and the analysis show that the carrier wave hasimprored the frequency specificity. of the electronic auditory prosthesis.

• Proceedings of the IEEK Conference
• /
• 1999.06a
• /
• pp.57-60
• /
• 1999

In many radio communication environments, there is a special component, called inter-symbol interference (ISI), mused by multipath time delay of signal and ISI components impose limitation of the data transmission rate. In this paper, we consider signaling pulse shapes, called partial response signaling (PRS), for minimizing the effect of ISI and show the improvement of performance by applying one of the partial-response signaling (PRS) pulses to two types of receiver system under dependent noise environments through the Monte-Carlo computer simulations.

• The Korean Journal of Physiology and Pharmacology
• /
• v.27 no.6
• /
• pp.541-553
• /
• 2023

Retinal prostheses have shown some clinical success in restoring vision in patients with retinitis pigmentosa. However, the post-implantation visual acuity does not exceed that of legal blindness. The reason for the poor visual acuity might be that (1) degenerate retinal ganglion cells (RGCs) are less responsive to electrical stimulation than normal RGCs, and (2) electrically-evoked RGC spikes show a more widespread not focal response. The single-biphasic pulse electrical stimulation, commonly used in artificial vision, has limitations in addressing these issues. In this study, we propose the benefit of multiple consecutive-biphasic pulse stimulation. We used C57BL/6J mice and C3H/HeJ (rd1) mice for the normal retina and retinal degeneration model. An 8 × 8 multi-electrode array was used to record electrically-evoked RGC spikes. We compared RGC responses when increasing the amplitude of a single biphasic pulse versus increasing the number of consecutive biphasic pulses at the same stimulus charge. Increasing the amplitude of a single biphasic pulse induced more RGC spike firing while the spatial resolution of RGC populations decreased. For multiple consecutive-biphasic pulse stimulation, RGC firing increased as the number of pulses increased, and the spatial resolution of RGC populations was well preserved even up to 5 pulses. Multiple consecutive-biphasic pulse stimulation using two or three pulses in degenerate retinas induced as much RGC spike firing as in normal retinas. These findings suggest that the newly proposed multiple consecutive-biphasic pulse stimulation can improve the visual acuity in prosthesis-implanted patients.