• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.6
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• pp.1-7
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• 2002

The use of an asymmetric Mach-Zehnder interferometric amplitude modulator to measure a relatively low frequency electric field strength is described. The sensitivity of an electric field sensor using a Ti:LiNbO$_3$ optical modulator is strongly affected by the shape of a electrode(probe antenna). To measure the low frequency electric field, a probe antenna of wide effective area is more useful than the usual dipole antenna. As a proof of this, the optical modulator was fabricated with a plate-type probe antenna and the usefulness of this antenna tested for measuring low frequency electric field strength. Measurements were performed in the range 0.1V/cm to 60V/cm at 60Hz through 100KHz. Using a probe antenna of 10mm$\times$10mm, the output voltage of 10㎷ was measured with respect to the electric field strength of 0.1V/cm at 60Hz. By increasing the effective area of the probe antenna, better sensitivity is obtainable over the measured range.

• Journal of The Korea Institute of Healthcare Architecture
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• v.24 no.2
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• pp.79-87
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• 2018

Purpose: The purpose of this paper is to provide logical basis on enlargement of toilet floor space for the disabled by "ACT ON GUARANTEE OF PROMOTION OF CONVENIENCE OF PERSONS WITH DISABILITIES, THE AGED, PREGNANT WOMEN. ETC" Revised Enforcement regulation [Asterisk 1] (2018.2.10.) and to help with making plans, designs and establishing policies by conducting experimental study with the enhanced floor area regulations. Methods: We conduct Experimental study, field work and interview for this paper. In experimental study, verification of the effective floor area was proceeded by measuring activity space for people in manual wheelchair, electric wheel chair and electric scooter and also reviewed useable area with the space expanded 0.2m both width and depth. In filed work, conducted an observation what other things (ex. sanitary equipment, hand rail and so on) can also affect the active space as well as effective floor space. In the interview, other problems and requirements that were not revealed were experimental study and observation of field work. Results : it's expected to provide better access to toilets for the disabled with the law revision of effective floor area. But, with the usage increasement of enlarged wheel chair and electric wheel chair, expanding side areas of toilet is also highly likely to be required going forward. Implications : Additional research is required on locations of exists and internal arrangement that effect the usage of toilet. It should be led to Universal design by making additional investigation and verification of the users patterns.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.1 s.31
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• pp.11-17
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• 2005

A lot of small-scale reservoirs that is extravagant in whole country are controlled state or real condition that correct data about the practice contents is not equipped all up to now. In this study, YungNam districts that region Gyeong-Ju city reservoir is distributed much of when flow speedily choose 23 peace among 73 small scale reservoir and experimented. Acquired data every 5 seconds, and user E/S and user value TS for orthocenter to 1 second interval and executes present condition measurement using RTK-GPS. Could was wave and state that reservoir of 15 places (about 65%) gives protective care that do 3D modelling with acquired data, and now correct contents about reservoir state past through comparative analysis with data. Also, area of full water and wave that analyze effective storage and area of full water of 23 places reservoir could know that 20.63%, effective storage decreased as 3.34%. I wish to contribute about analysis about present reservoir state through this and method the adminstration direction.

• Journal of the Earthquake Engineering Society of Korea
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• v.16 no.2
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• pp.35-45
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• 2012

Pseudo static analysis using the Mononobe-Okabe method and numerical analysis considering a small strain nonlinearity from the soil were performed to determine the bearing pressure changes of the inverted T-type retaining wall subjected to earthquake motions. In many cases, an inverted 'T' type retaining wall of more than 10 m shows bearing capacity failure under earthquake conditions, despite showing sufficient bearing capacity during normal conditions. The most important reason for this is the change of the effective base area during an earthquake. In this paper, the change of the effective base area of an inverted 'T' type wall is analyzed by using finite difference element code (FLAC). In addition, the effect of dynamic bearing capacity coefficients (which has been suggested by several researchers but not adopted in current design codes and procedures) was verified.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.1 s.232
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• pp.67-73
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• 2005

The paper presents a single-heater microfluid injector, whose ejected droplet volume is adjusted by digital current path control for a single microheater. The previous droplet volume adjustable methods have used the digital current control for multiple heaters or the analog current control for a single heater, while the present method uses the digital current control for a single microheater. Two different microinjectors, having a rectangular heater and a circular hearter, are designed and fabricated in the chip area of $7.64\;mm{\times}5.26\;mm$. The fabricated microinjectors have been tested and characterized for the number, size, shape and lifetime of the generated bubbles as well as for the volume and velocity of the ejected droplets. The input power for the rectangular heater and the circular heater has been varied in the ranges of $8.7{\sim}24.9{\mu}W\;and\;8.1{\sim}43.8{\mu}W$, respectively. The projected area of the generated bubble has been changed in the ranges of $440{\sim}l,3600{\mu}m^2\;and\;800{\sim}3,300{\mu}m^2$ for the rectangular heater and the circular heater, respectively. The microinjector with the rectangular heater ejects three discrete levels of the droplet in the volume range of $9.4{\sim}20.7pl$ with the velocity range of $0.8{\sim}1.7m/s$, while the microinjector with the circular heater achieves five discrete levels of the droplet in the volume range of $7.4{\sim}27.4pl$ with the velocity range of $0.5{\sim}2.8m/s$.

• Fire Science and Engineering
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• v.31 no.4
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• pp.52-58
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• 2017

This study investigated the pressure difference distribution and the flow characteristics among room, ancillary room, and stair case by carrying out the numerical simulations on the air flow inside the pressurized air supply smoke control system. Numerical simulations were conducted to analyze pressure and velocity distribution of compartments by pressurized air supply for the air-leakage test facility which was built to measure the effective leakage area. In this study, the leakage of air was considered by locating the narrow slit onto fire door and window of room. Simulated results using this method precisely followed the previous experimental results for the pressure differences between the stair case and ancillary room. Predicted results showed that the local leakage of air rarely affected the overall flow pattern and pressure distribution. Although the average velocity over the door between room and ancillary room satisfied the regulation for fire safety, it was certified the unsafe outflow to ancillary room could be occurred in the local position such as the upper part of the door.

• Journal of Korea Water Resources Association
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• v.44 no.12
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• pp.941-954
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• 2011

In this study, past method and recent method for flood discharge with domestic multi-purpose dams in Korea were compared and analyzed with respect to the scale of watershed. Rainfall depth, temporal pattern, rainfall excess, rainfall-runoff model, parameter estimation and base flow were selected as the principal factors affecting flood discharge and effects on flood discharge were analyzed quantitatively by using sensitivity analysis. The results showed that the flood discharges calculated by past and recent method increased and decreased with a wide range of discharge with respect to the scale of watershed. The reason for decrease of flood discharge is the exchange of temporal pattern of rainfall and the principal reasons for increase of flood discharge are the increase of rainfall depth by unusual weather phenomena and the difference of estimation method for parameters of unit hydrograph.

• Journal of the Korea Society for Simulation
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• v.24 no.3
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• pp.89-96
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• 2015

In order to use missiles more effectively, assessing methodologies was advanced about weapon effects for various target types. We tried to find out the most effective analysis methodologies for missiles to attack 3 dimensional building target's and analyzed adaptedness as an assessing methodology. There are EFD (Expected Fractional Damage) and SSPD (Single Sortie Probability of Damage) methodologies to assess building target damage. In order to calculate effectiveness we used input parameter such as size of the target and CEP (Circular Error Probable), MAE_bldg (Mean Area of Effects for Building) of weapons and impact angle as encountering condition between the target and the missile. We compared EFD and SSPD, in order to analyze adaptedness as a effective methodology by CEP and MAE. The result was that EFD methodology was more adaptive to assess 3 dimensional building targets by missile systems than SSPD.

• Journal of the Korean Geophysical Society
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• v.9 no.2
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• pp.113-120
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• 2006

A lot of small-scale reservoirs that is extravagant in whole country are controlled state or real conditionthat correct data about the practice contents is not equipped all up to now. In this study, YungNam districts that region Gyeong-Ju city reservoir is distributed much of when flow speedily choose 23 peace among 73 small scale reservoir and experimented. Acquired data every 5 seconds, and user E/S and user value TS for orthocenter to 1 second interval and executes present ondition measurement using RTK-GPS. Could was wave and state that reservoir of 15 places (about 65%) gives protective care that do 3D modelling with acquired data, and now correct contents about reservoir state past through comparative analysis with data. Also, area of full water and wave that analyze effective storage and area of full water of 23 places reservoir could know that 20.63%, effective storage decreased as 3.34%. I wish to contribute about analysis about present reservoir state through this and method the adminstration direction.

• Membrane Journal
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• v.29 no.5
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• pp.292-298
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• 2019

The purpose of this study was to improve the desalination performance by using split electrodes in the capacitive desalination process. The experiment was carried out by measuring the desalination efficiency of the NaCl aqueous solution according to the partitioning of the electrode at 20 mL/min flow rate, 1.2 V, 3 min adsorption conditions, and -1 V, 1 min desorption conditions. The desalination efficiency for the non-divided electrodes with a surface area of $146cm^2$ reached 40% while the divided electrode with a surface area of $133cm^2$ showed a desalination efficiency of 57%. The desalination efficiency of the same split electrode was 49% at 2 cm divided interval and 57% at 1cm divided interval. The desalination efficiency of the split electrode was higher than that of the normal CDI and narrower divided intervals increased the performance.