• Explosives and Blasting
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• v.24 no.2
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• pp.41-50
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• 2006

Excavation by explosives blasting necessarily involves noise and vibration, which is highly prone to face claims on the environmental and structural aspects from the neighbors. When the blasting carried out in the vicinity of a structure, the effect of blasting vibration on the stability of the structure should be carefully evaluated. In the conventional method of evaluation, an equation for blast vibration is obtained from test blasting which is later used to determine the amount of charge. This method, however, has limitations in use since it does not consider topography and change in ground conditions. In order to overcome the limitations, dynamic numerical analysis is recently used in continuum or discontinuous models, where the topography and the ground conditions can be exactly implemented. In the numerical analysis for tunnels and rock slopes, it is very uncommon to simulate multi-hole blasting. A single-hole blasting pressure is estimated and the equivalent overall pressure at the excavation face is used. This approach based on an ideal case usually does not consider the ground conditions. And this consequently results in errors in calculation. In this presentation of a case study, a new approach of using blast waves obtained in the test blast is proposed. The approach was carried out in order to improve the accuracy in calculating blasting pressure. The stability of a structure in the vicinity of a slope blasting was examined using the newly proposed method.

• Korean Journal of Cognitive Science
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• v.11 no.3_4
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• pp.83-93
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• 2000

The effect of immediate and delayed recognition memory on event-related potential (ERP) was studied using a continuous recognition memory task and event-related potential (ERP). Among 240 stimulus words 40 words were not repeated. 100 were immediately repeated and 100 were repeated after 5 intervening words. All words presented only once during the experiment were referred to as new words. Subjects responded faster and more accurately to words repeated immediately than to new words a and to those repeated after intervening words. In terms of ERP results the immediately repeated words were associated with large P300 amplitude, early P300 latency and a absence of N400. while words repeated after a delay were associated with small P300 a amplitude. late P300 latency and the presence of N400. N400 was elicited only to new w words and to those repeated after a delay. The general morphology of the waveform was s similar for three stimulus-presentation conditions until around 3l0ms after the onset of stimulus. These results indicate that immediate and delayed recognition memory could be dissociated into two distinct processes possibly being mediated by different cerebral mechanism, and the dissociation between two types of recognition memory emerges around 3l0ms poststim'ulus. The immediate and delayed recognition memory for words are considered in terms of template matching and memory searching.

• Journal of the Korean Magnetics Society
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• v.12 no.6
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• pp.206-211
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• 2002

We have constructed a new kind of magnetic motion capture sensor based on the pulse magnetic field method. 3-orthogonal magnetic pulse fields were generated in turns only one period of sinusoidal waveform using 3-orthogonal magnetic dipole coils, ring counter and analog multiplier. These pulse magnetic fields were measured with 3-orthogonal search coils, of which induced voltages by the x-, y-, and l-dipole sources using S/H amplifier at the time position of maximum induced voltage. Using the developed motion capture sensor, we can measure position of sensor with uncertainty of ${\pm}$0.5％ in the measuring range from ${\pm}$0.5 m to ${\pm}$1.5 m.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.4
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• pp.9-14
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• 2003

The new optical link receiver with data transfer rate higher than 10Mbps at the supply voltage of 1.8V was designed and fabricated using bipolar technology. The fabricated IC showed the dissipation current of 4.6mA under high level input voltage of 1.5V. The high level output voltage($V_{OH}$) and the low level output voltage($V_{OL}$) were 1.15V and 0V, respectively, for a given 10 Mbps signal which has duty ratio of 50%, $V_{IL}$(low level input voltage) of 0.5V, and $V_{IH}$(high level input voltage) of 1.5V, The duty ratio of output waveform was 52.6%. The rising time(t$_{r}$) and the falling time(t$_{f}$) were 9.5ns and 6.8ns, respectively. The propagation delay difference($t_{PHC}-t_{PLH}$) and the jitter($t_j$) were 11.7ns and 4.3ns, respectively.y.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.219-225
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• 2014

The New efficient Mux-based scan latch cell design and scan test of LOS/LOC modes are proposed for detection of delay faults in digital logic circuits. The proposed scan cell design can support LOS(Launch-off-Shift) and LOC(Launch-off-Capture) tests with high fault coverage and low scan power and it can alleviate the problem of the slow selector enable signal and hold signal by supporting the logic capable of switching at the operational clock speeds. Also, it efficiently controls the power dissipation of the scan cell design during scan testing. Functional operation and timing simulation waveform for proposed scan hold cell design shows improvement in at-speed test timing in both test modes.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.3
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• pp.19-25
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• 2008

In this paper, author proposes a novel step-up AC-DC chopper operated with power factor correction(PFC) and with high efficiency. The proposed chopper behaves with discontinuous current control(DCC) of input current. The input current waveform in the proposed chopper is got to be a discontinuous sinusoid form in proportion to magnitude of ac input voltage under the constant duty cycle switching. Therefore, the input power factor is nearly unity and the control method is simple. In the general DCC chopper, the switching devices are turned-on with the zero current switching, but turn-off of the switching devices is switched at current maximum value. To achieve a soft switching of the switching rum-off, the proposed chopper is used a new partial resonant circuit. The result is that the switching loss is very low and the efficiency of chopper is high.

• Journal of Biomedical Engineering Research
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• v.28 no.6
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• pp.768-776
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• 2007

A new type of the fluid circulation blood pressure simulator was proposed to enhance the blood pressure simulator used for the development and evaluation of automatic sphygmomanometers. Various pressure waveform of fluid flowing in the pipe was reproduced by operating the proportional control valve after applying a pressure on the fluid in pressurized oil tank. After that, appropriate fluid was supplied by operating the proportional control valve, which enabled to reproduce various pressure wave of the fluid flowing in the tube. To accomplish this work, the mathematical model was carefully reviewed in cooperating with the proposed simulator. After modeling the driving signal as input signal and the pressure in internal tube as output signal, the simulation on system parameters such as internal volume, cross-section of orifice and supply pressure, which are sensitive to dynamic characteristic of system, was accomplished. System parameters affecting the dynamic characteristic were analyzed in the frequency bandwidth and also reflected to the design of the plant. The performance evaluator of fluid dynamic characteristic using proportional control signal was fabricated on the basis of obtained simulation result. An experimental apparatus was set-up and measurements on the dynamic characteristic, nonlinearity, and rising and falling response was carried out to verify the characteristic of the fluid dynamic model. Controller was designed and thereafter, simulation was performed to control the output signal with respect to the reference input in the fluid dynamic model using the proposed proportional control valve. Hybrid controller combined with an proportional controller and feed-forward controller was fabricated after applying a disturbance observer to the control plant. Comparison of the simulations between the conventional proportional controller and the proposed hybrid simulator indicated that even though the former showed good control performance.

• Journal of Sensor Science and Technology
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• v.16 no.1
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• pp.24-32
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• 2007

Conductive rubber material was molded in a belt shape to measure respiration. Its resistivity was approximately $0.03{\;}{\Omega}m$ and the resistance-displacement relationship showed a negative exponent. The temperature coefficient was approximately $0.006{\;}k{\Omega}/^{\circ}C$ negligible when practically applied on the abdomen. The conductive rubber belt was applied on a normal male's abdomen with the dimensional change measured during resting breathing. The abdominal signal was differentiated ($F_{m}$) and compared with the accurate standard air flow rate signal ($F_{s}$) obtained by pneumotachometry. $F_{m}$ and $F_{s}$ differed in waveform, but the start and end timings of each breaths were clearly synchronized, demonstrating that the respiratory frequency could be accurately estimated before further processing of $F_{m}$. $F_{m}-F_{s}$ loop showed a nonlinear hysteresis within each breath period, thus 6 piecewise linear approximation was performed, leading to a mean relative error of 14 %. This error level was relatively large for clinical application, though customized calibration seemed feasible for monitoring general variation of ventilation. The present technique would be of convenient and practical application as a new wearable respiratory transducer.

• Journal of Broadcast Engineering
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• v.22 no.6
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• pp.693-701
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• 2017

In this paper, we propose a new method for music genre classification using spikegram and deep neural network. The human auditory system encodes the input sound in the time and frequency domain in order to maximize the amount of sound information delivered to the brain using minimum energy and resource. Spikegram is a method of analyzing waveform based on the encoding function of auditory system. In the proposed method, we analyze the signal using spikegram and extract a feature vector composed of key information for the genre classification, which is to be used as the input to the neural network. We measure the performance of music genre classification using the GTZAN dataset consisting of 10 music genres, and confirm that the proposed method provides good performance using a low-dimensional feature vector, compared to the current state-of-the-art methods.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.3
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• pp.262-268
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• 2016

Hemifacial spasm is a disease caused by involuntary facial muscles with repeated unilateral convulsive spasms. It involves contraction of multiple muscles at the same time (synkinesia). The pathogenesis appears to be the pressure on the vessel by the facial nerve. This study included hemifacial spasm patients, who received microvascular decompression surgery. Brainstem auditory evoked potential and the examination time were carefully noted when using brain surgical retractor. The facial nerve electromyography tests for the identification of artifacts and EMG waveform when the facial nerve damage, about the importance of the maintenance of anesthesia in the lateral spread response and in a somatosensory evoked potential propose a new method. Based on the above test, it will be more effective.