• The Journal of the Acoustical Society of Korea
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• v.26 no.1
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• pp.8-15
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• 2007

Speech intelligibility of the eavesdropping sound is investigated on a acoustic cavity - glass window coupled system. Using MLS (Maximum Length Sequency) signal as a sound source, acceleration and velocity responses of the glass window are measured by accelerometer and laser doppler vibrometer. MTF (Modulation Transfer Function) is used to identify tile speech transmission characteristics of the cavity and window system. STI (Speech Transmission Index) based upon MTF is calculated and speech intelligibility of the vibration sound of the glass window is estimated. Speech intelligibilities by the acceleration signal and the velocity signal are compared. Finally, intelligibility of the conversation sound is confirmed by the subjective test.

• The Journal of the Acoustical Society of Korea
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• v.28 no.2
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• pp.127-134
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• 2009

In this study, possibility of the laser eavesdropping is investigated on the window glasses with various thicknesses, Glass windows are excited by maximum length sequency (MLS) signal and the vibration sound is detected by a laser doppler vibrometer. From the detected sound, speech intelligibility is objectively estimated. Speech transmission index (STI), which is based on the modulation transfer function (MTF). is calculated for the estimation. Finally, disturbing wave effect on the speech intelligibility is analysed by using an outside speaker and a window shaker attached on the glass window. The purpose of the study is to estimate the possibility of remote eavesdropping by the laser sensor and to evaluate the performance of the homemade window shaker to protect from the remote eavesdropping.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.85-86
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• 2016

Recently, needs for the window cleaning for 2~5 stories in a building has been increased but existing window cleaning work by workers is not easy to clean the windows. Therefore a demand for development of alternative techniques have been raised. The purpose of this study is to analyze feasibility of development of the guide rail-type cleaning device for cleaning window for the lower stories. For this, we analyze the status of the job, such as risk, limitations of by workers and examine the potential producer needs through interviewing field experts of the cleaning work. Futhermore, we define the required features of the window cleaning device and proposed the validity of the relised device development of the function.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.211-215
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• 2009

As entering in the time of high oil price, seriousness of an energy is on the rise and the importance of energy is growing. Especially, building energy occupying 24% of total demand of energy is expected to be possible to reduce energy demand more than other section. To reduce the building energy consumption, this study analyzes function and thermal performance of Super window by heat experimental apparatus. Super window is a 2-track low-e glazing window for high insulation efficiency. By applying the results of this experiment to building energy efficiency rating tool, this study compares energy efficiency rates depending on a region.-Jeju, South, Central. And it shows how much does Super window reduce Building energy consumption.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.12
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• pp.46-54
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• 2015

SAR is a Radar to obtain the video information using a radio wave. Platform emit the radio wave, depending backscattered waves returned from the target object the signal to the distance, to create a topographical map is recorded in two-dimensional image. In this paper, through a simulation to apply a variety of window in the SAR image processing for SAR image recovery is to study the application effect of the window, as a result, at the side of the signal of the SNR, Flattop window to improve the best performance it was confirmed to show.

• Journal of the Korean housing association
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• v.17 no.2
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• pp.125-134
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• 2006

The tightness of windows have devoted to the improvement of thermal insulation and energy saving in buildings. But it is known that this tightness causes some side effects such as low ventilation, low capacity to humidity and temperature control and these are not profitable for inhabitants. To act on these side effects, Korean traditional windows which are composed of Han-Ji(Koreand traditional paper) and Chang-Sal(Korean traditional wooden frame) have been studied to get a reasonable solutions for these problems. In this study, to compare the thermal and humidity control performance of current window(12 mm pair) and Korean traditional windows, frames which are made of existing window and Korean traditional windows are adapted to scale model house and then humidity and temperature of in and out of scale model house are measured and analysed. The results of this study are followings ; 1) When Korean traditional window charges 20cm(1/8 of total window area) from total window area, Han-Ji window has higher thermal insulation than that of existing window in daytime. There is the most big thermal difference when double faced with double-ply Han-Ji window is placed to mock-up house. In night-time, the temperature difference is very small so this means that Korean traditional window is good to cover direct sunlight in daytime and reduce the temperature of balcony. One faced with one-ply han-Ji window has the best humidity penetration performance among three type of Korean traditional windows. 2) When Korean window area enlarged to 40cm(1/4 of total window area), the function of 40cm width Han-Ji window is higher than that of 20cm's. This means that enlargement of Han-Ji window cover direct sunlight more and is more efficient in humidity penetration.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.10a
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• pp.80-85
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• 1995

Too see the effects of finite record on the estimation of WVD in practice, a window which has time varying length is examined. Its length increases linearly with time in the first half of the record, and decreases from the center of the record. The bias error due to this window decreases inversely proportionally to the window length as time increases in the first half. In the second half, the bias error increases and the resolution decreases as time increases. The bias error due to the smoothing of WVD, which is obtained by two-dimensional convolution of the true WVD and the smoothing window, which has fixed lengths along time and frequency axes, is derived for arbitrary smoothing window function. In the case of using a Gaussian window as a smoothing window, the bias error is found to be expressed as an infinite summation of differential operators. It is demonstrated that the derived formula is well applicable to the continuous WVD, but when WVD has some discontinuities, it shows the trend of the error. This is a consequence of the assumption of the derivation, that is the continuity of WVD. For windows other than Gaussian window, the derived equation is shown to be well applicable for the prediction of the bias error.

• Journal of the Korean Institute of Educational Facilities
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• v.4 no.4
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• pp.29-41
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• 1997

The objective of this paper is to construct a model to be used in deciding whether to repair or rebuild school buildings is depending on their ages and other factors. The theme of this paper is the age is the main variable but other factors such as floor, innerwall, ceiling, door, inner window of the class room, outer window of the class room, inner window of the corridor, outer window of the corridor, middle window between the classroom and the corridor, light, heater, speaker, fire protection sensor, TV monitor, and telephone status would influence the final decisions. This paper employs an experimental case study method. Using the stepwise, statistical, classification method commonly used in discriminant analysis, it evaluates 12,766 rooms of 87 different high schools in Seoul. The result of this study indicates that some critical variables influencing the final decisions are the status of TV monitor, middle window between the classroom and the corridor, light, inner window of the corridor, fire protection sensor, innerwall, speaker utensil, outer window of the class room, and door of the class room. This paper also suggests a linear discriminant function will be used for this kind of studies. Finally the paper recommends policies with respect to the variables and discriminant functions evaluated.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.35-38
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• 2004

In this paper, we investigate and analyze the problems encountered in frame-based estimation of TDOA(Time Difference of Arrival) using CPSP function. Spectral leakage occurring in framing of a speech signal by a rectangular window makes estimation of CPSP spectrum inaccurate. Framing with a Hamming window to reduce the spectral leakage effect distorts the signal due to the different weighting at temporally same sample, which make the TDOA estimation using CPSP function inaccurate. In this paper, we solve this problem by reducing the dynamic range of the spectrum of a speech signal with preemphasis. Experimental results confirm that the framing of pre-emphasized microphone output with a rectangular window shows higher success ratio of TDOA estimation than any other framing methods.

• The Korean Journal of Applied Statistics
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• v.27 no.7
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• pp.1197-1205
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• 2014

Typical clinical dose development studies consist of the comparison of several doses of a drug with a placebo. The primary interest is to find therapeutic window that satisfying both efficacy and safety. In this paper, we propose nonparametric method for identifying effective and safe doses in linear placement using score function. The Monte Carlo simulation is adapted to estimate the power and the family-wise error rate(FWE) of proposed procedure are compared with previous methods.