• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.3
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• pp.470-477
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• 2001

Constant ΔK fatigue crack growth tests were performed by applying an intermediate multiple overload for S45C steel. The purpose of the present study is to investigate effects of specimen thickness at various baseline stress intensity factor range levels (ΔK(sub)b), overload application position (a/W) and overload application frequency (OL(sub)HZ) on fatigue crack growth retardation behavior. The principal results are summarized as follows. The amount of retardation for a given ΔK(sub)b level is increased with increasing the baseline stress intensity factor range level for all specimen thickness. The normalized minimum crack growth rate is increased with increasing the specimen thickness, except for ΔK=45MPa√m. The retardation cycle is decreased with increasing a/W and increased with OL(sub)HZ.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.11 no.1
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• pp.69-75
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• 2000

Background and Objectives : The Voice Range Profile(VRP) is a two-dimensional graphic dysplay of an individual's amplitude range as a function of total fundamental frequency range. It is designed as a maximum performance test which can be used as a general indicator of voice problems in the non-professional voice and as a sensitive indicator of problems with the professional voice. The purpose of the study is to obtain a baseline VRT for the classical professional singers and compare it with the normal nonsinger's profile. We also compared the difference of VRP between the classical professional singers who have normal vocal fold and who have vocal folds lesions without dysphonia. Materials and Methods : The VRPs were elicited. from 42 trained classical singers(Soprano 26, Mesosoprano 5, Tenor 9, Bariton 2) and 20 untrained nonsingers(female 10, male 10) using Voice Range Profile Model 4326(Kay Elemetrics USA). The mean values for phonational range with highest and lowest pitch level and range of voice intensity with maximum and minimum intensity level were compared between classical singers and nonsingers. Results and Conclusions : The frequency range and dynamic range were significantly increased for the classical singers in comparison to the nonsingers. But there was no significant difference were found for the VRP between the parts in the classical singers. The classical singers who have vocal fold lesions showed slightly decreased VRP compared to those with healthy vocal folds.

• Journal of Life Science
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• v.9 no.6
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• pp.646-652
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• 1999

The effect of temperature on the structure change of the SH of myosin head have been investigated with improved resolution by x-ray diffraction using synchrotron radiation. The movement of myosin head and conformational change of contractile molecules were occurred in the muscle contraction. IASL (iodo acetamide) and MSL (maleimide) disordered the orderly helix arrangement of myosin in the rest state of spin level. The temperature effect on the structure change was great at the UL in the equatorial reflection. But those of IASL and MSL were minor. Equatorial reflection (10, 11) change inferred that myosin head was moved to the vicinity of actin filament by temperature change (from $25^{\circ}C$ to $0^{\circ}C$) at UL, but spin level was not changed. The intensity change of 143 $\AA$ and 72 $\AA$ could offer information of the mass profection of population of myosin heads along the filament axis. The slope of intensity profile of the mass profection of 143$\AA$ and reflection of MSL is appeared sharply and those of UL and IASL were not changed. The decrease of MSL actin reflection at 51 $\AA$ and 59 $\AA$ in the actin reflection change refers that the shifted myosin head binds a certain actin or changes an actin structure. From these results, we could conclude that IASL and MSL were spin labeled on SH of myosin head and disordered the helix arrangement of actin.

• Advances in environmental research
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• v.6 no.2
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• pp.139-146
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• 2017

The purpose of this study was to determine the present air pollutant concentrations and predicted levels for next 30 years in urban environment of Karachi city. For that, a total of fifty measurements were made for each twenty selected locations of the city. The locations were selected on the basis of land use pattern such as residential, commercial, industrial settlements, open areas, congested traffic and low traffic areas for investigation of air pollutants variability and intensity. The measurements were taken continuously for six months period using PM Meter, Model AEROCET 531 and Ambient Air Quality Meter, Model AAQ 7545. The concentration of air pollutants were found higher at Al Asif Square and Maripur Road due to higher intensity of traffic and at Korangi Crossing because of industrial areas. The level of pollutants was lower at Sea View owing to lower traffic congestion and transportation of pollutants by sea breezes.

• The Journal of the Acoustical Society of Korea
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• v.15 no.5
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• pp.90-98
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• 1996

An auditory model is proposed for robust speech recognition in noisy environments. The model consists of cochlear bandpass filters and nonlinear stages, and represents frequency and intensity information efficiently even in noisy environments. Frequency information of the signal is obtained by zero-crossing intervals, and intensity information is also incorporated by peak detectors and saturating nonlinearities. Also, the robustness of the zero-crossings in estimating frequency is verified by the developed analytic relationship of the variance of the level-crossing interval perturbations as a function of the crossing level values. The proposed auditory model is computationally efficient and free from many unknown parameters compared with other auditory models. Speaker-independent speech recognition experiments demonstrate the robustness of the proposed method.

• Publications of The Korean Astronomical Society
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• v.20 no.1 s.24
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• pp.7-10
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• 2005

We have calculated 2448 interstellar cloud models to investigate the formation and destruction of high rotational level $H_2$ according to the combinations of five physical conditions: the input UV intensity, the $H_2$ column density, cloud temperature, total density, and the $H_2$ formation rate efficiency. The models include the populations of all the accessible states of $H_2$ with the rotational quantum number J < 16 as a function of depth through the model clouds, and assume that the abundance of $H_2$ is in a steady state governed primarily by the rate of formation on the grain surfaces and the rates of destruction by spontaneous fluorescent dissociation following absorption in the Lyman and Werner band systems. The high rotational levels J = 4 and J = 5 are both populated by direct formation into these levels of newly created molecules, and by pumping from J = 0 and J = 1, respectively The model results show that the high rotational level ratio N(4)/N(0) is proportional to the incident UV intensity, and is inversely proportional to the $H_2$ molecular fraction, as predicted in theory.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.205-208
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• 2008

In this paper, we have measured and compared the optical and electrical characteristics of LED(light emitting diode) and CNT(carbon nano-tube) lightings. Especially, the IES format files are used for each of the luminaire LlD(luminous intensity distribution) analysis and light level simulation for analyze the maximum, minimum, and average light level. In the future, when CNT and the LED based lighting technology standards are writing, this data will be used in judging.

• Earthquakes and Structures
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• v.4 no.3
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• pp.299-324
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• 2013

The current research focuses on the seismic vulnerability assessment of typical Southern Europe buildings, based on processing of a large set of observational damage data. The presented study constitutes a sequel of a previous research. The damage statistics have been enriched and a wider damage database (178578 buildings) is created compared to the one of the first presented paper (73468 buildings) with Damage Probability Matrices (DPMs) after the elaboration of the results from post-earthquake surveys carried out in the area struck by the 7-9-1999 near field Athens earthquake. The dataset comprises buildings which developed damage in several degree, type and extent. Two different parameters are estimated for the description of the seismic demand. After the classification of damaged buildings into structural types they are further categorized according to the level of damage and macroseismic intensity. The relative and the cumulative frequencies of the different damage states, for each structural type and each intensity level, are computed and presented, in terms of damage ratio. Damage Probability Matrices (DPMs) are obtained for typical structural types and they are compared to existing matrices derived from regions with similar building stock and soil conditions. A procedure is presented for the classification of those buildings which initially could not be discriminated into structural types due to restricted information and hence they had been disregarded. New proportional DPMs are developed and a correlation analysis is fulfilled with the existing vulnerability relations.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.55-60
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• 2000

Constant ${\Delta}K$ fatigue crack growth tests were performed applying an intermediate multiple overload for SM45C steel. The purpose of the present study is to investigate the effects of specimen thickness at various baseline stress intensity levels$({\Delta}K_b)$, overload application frequency(a/W) and overload application frequency$(OL_{HZ})$ on fatigue crack growth retardation behavior. The principal results are summarized as follows. The amount of retardation for a given ${\Delta}K_b$ level is increased with increasing the baseline stress intensity level in all specimen thickness. The normalized minimum crack growth rate is increased with increasing the specimen thickness, except for ${\Delta}K=45MPa \sqrt m$. The retardation cycle is decreased with increasing the overload application position and increased with the overload application frequency.

• Journal of Biosystems Engineering
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• v.25 no.2
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• pp.131-140
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• 2000

Spraying operation is one of the most essential in an orchard management and it is also hazardous to human body. for automatic and unmanned spraying , an autonomous travelling vehicle is demanded. In this study, a telemeter was developed using infrared beam which could detect trunks and obstacles measure distance and direction from the vehicle travelling in the orchard. The telemeter system was composed of two infrared LED transmitters and receivers, a beam scanning device for continuous object detection , two rotary encoders for angle detector, and a beam level controller for uneven soil surface. The detected distance and direction signal s were sent to personal computer which made for the system display the angular and distance measurements through I/O board. According to a field test in an apple farm, the system detected up to 10m distance under 12 V of transmitted beam intensity, however, it was recommended that the proper beam transmit intensity be 7 v at the 10 m distance, because of the negative effect to human body at 12 V. The error rate of this system was 0.92 % when the actual distance was compared to measured one. The system was feasible at the small error rate. The developed telemeter system was an important part for autonomous travelling vehicle provided the real time object recognition . A direction control system could be constructed suing the system. It is expected that the system could greatly contribute to the development of autonomous farm vehicle.