• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.828-835
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• 2017

Airtightness of buildings is one of critical aspects of its energy performance. To build up references of airtightness of wooden houses built in Korea, blower door tests have been carried out in 42 houses since 2006. Causes of air leakage were investigated recently. The average value of air change rate was $3.7h^{-1}$ for light frame house and $5.5h^{-1}$ for post-beam construction at ACH50 (air change per hour at 50 Pa air pressure difference). Foam type insulation was more advantageous in ensuring building airtightness than glass fiber batt. Airtightness of wooden houses which were constructed after 2010 was improved to have less than $1.5h^{-1}$ of ACH50, threshold for application of artificial air change. The average air change rate of CLT (cross laminated timber) houses showed the lowest value, $1.1h^{-1}$, among the tested structures.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1287-1292
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• 2005

This paper presents an effective pattern classification model by designing an artificial neural network based pattern classifiers for face recognition. First, a RGB image inputted from a frame grabber is converted into a HSV image which is similar to the human beings' vision system. Then, the coarse facial region is extracted using the hue(H) and saturation(S) components except intensity(V) component which is sensitive to the environmental illumination. Next, the fine facial region extraction process is performed by matching with the edge and gray based templates. To make a light-invariant and qualified facial image, histogram equalization and intensity compensation processing using illumination plane are performed. The finally extracted and enhanced facial images are used for training the pattern classification models. The proposed H-ART2 model which has the hierarchical ART2 layers and F-LVQ model which is optimized by fuzzy membership make it possible to classify facial patterns by optimizing relations of clusters and searching clustered reference patterns effectively. Experimental results show that the proposed face recognition system is as good as the SVM model which is famous for face recognition field in recognition rate and even better in classification speed. Moreover high recognition rate could be acquired by combining the proposed neural classification models.

• BMB Reports
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• v.41 no.4
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• pp.338-343
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• 2008

Dehydrins (DHNs) compose a family of intrinsically unstructured proteins that have high water solubility and accumulate during late seed development at low temperature or in water-deficit conditions. They are believed to play a protective role in freezing and drought-tolerance in plants. A full-length cDNA encoding DHN (designated as ClDhn) was isolated from an oriental medicinal plant Codonopsis lanceolata, which has been used widely in Asia for its anticancer and anti-inflammatory properties. The full-length cDNA of ClDhn was 813 bp and contained a 477 bp open reading frame (ORF) encoding a polypeptide of 159 amino acids. Deduced ClDhn protein had high similarities with other plant DHNs. RT-PCR analysis showed that different abiotic stresses such as salt, wounding, chilling and light, triggered a significant induction of ClDhn at different time points within 4-48 hrs post-treatment. This study revealed that ClDhn assisted C. lanceolata in becoming resistant to dehydration.

• Solar Energy
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• v.17 no.3
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• pp.35-41
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• 1997

An experimental study was carried out in a vertical channel with square heat source by visualization equipment with laser apparatus. The image processing system consists of one commercial image board slit into a personal computer and 2-dimensional sheet light by Argon-Ion Laser with cylindrical lens and flow picture recording system. Instant simultaneous velocity vectors at whole field were measured by 2-D PIV system which adopted two-frame grey-level cross correlation algorithm. Heat source was uniform heat flux(5W). The obtained results show various flow patterns such as the kinetic energy distribution and the turbulent kinetic energy distribution.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.11
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• pp.1211-1216
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• 2013

In this study, a dynamic camera actuation system for simultaneous in situ image acquisition is developed to achieve real-time observation of transient liquid flow on a lab-on-a-disk. A disk-type electric circuit, namely circuit-on-a-disk, co-rotated with the lab-on-a-disk improves the dynamic image acquisition ability in terms of a frame rate. The circuit-on-a-disk is comprised of a camera connected with a motor, a microprocessor and a wireless communication module. The camera connected with the motor enables to realize dynamic tracking of a transient flow and real-time image acquisition. The obtained images can be simultaneously transferred by a video/audio transmitter unit to a personal computer. Also, the microprocessor receives signals from the personal computer, and then controls the focusing position of the camera. We are expecting that heaters, sensors, and light sources also can be integrated on the circuit-on-a-disk, and they will enable various functional actuations as well as precise image acquisition.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.52-59
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• 2006

Surface qualities of a micro-processed sample with a pulse laser have been investigated by making use of scanning confocal microscope(SCM) and atomic force microscope(AFM). Samples are bump electrodes and ITO glass of LCD module used in a mobile phone and a wafer surface scribed by UV laser. A image of $140{\times}120{\mu}m^2$ is obtained within 1 second by SCM because scan speed of a x-axis and y-axis are 1kHz and 1Hz, respectively. AFM is able to correctly measure the hight and width of ITO, and scribing depth and width of a wafer with a resolution less than 300nm. However, the scan speed is slow and it is difficult to distinguish a surface composed of different kinds of materials. Results show that SCM is preferable to obtain a image of a sample composed of different kinds of material than AFM because the intensity of a reflected light from the surface is different for each material.

• Earthquakes and Structures
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• v.13 no.3
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• pp.289-297
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• 2017

This paper presents seismic performance and reliability evaluation on steel-timber hybrid shear wall systems composed of steel moment resisting frames and infill light frame wood shear walls. Based on experimental observations, damage assessment was conducted to determine the appropriate damage-related performance objectives for the hybrid shear wall systems. Incremental time-history dynamic analyses were conducted to establish a database of seismic responses for the hybrid systems with various structural configurations. The associated reliability indices and failure probabilities were calculated by two reliability methods (i.e., fragility analysis and response surface method). Both methods yielded similar estimations of failure probabilities. This study indicated the greatly improved seismic performance of the steel-timber hybrid shear wall systems with stronger infill wood shear walls. From a probabilistic perspective, the presented results give some insights on quantifying the seismic performance of the hybrid system under different seismic hazard levels. The reliability-based approaches also serve as efficient tools to assess the performance-based seismic design methodology and calibration of relative code provisions for the proposed steel-timber hybrid shear wall systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.891-898
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• 2014

The DVC (Distributed Video Coding) provides a theoretical basis for the implementation of light video encoder. Conventionally, lots of studies have been focused on the codec scheme of Stanford University that has a feedback channel to control the bit rate finely. However, the codec scheme can not evaluate the qualities of the frames reconstructed by the received parity bits at the decoder side. This paper presents an efficient method of estimating distortion by correcting the virtual channel noises in side information and then facilitating the measurements of the visual qualities. Through several simulations, it is shown that the proposed method is very efficient in estimating the visual qualities of the reconstructed WZ frames.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.4
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• pp.437-442
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• 1997

An experimental study was carried out in a channel cavity with square heat surface by visual¬ization equipment with Mach - Zehnder interferometer and laser apparatus. The image processing system consists of one commercial image board slit into a personal computer and 2-dimensional sheet light by Argon-Ion Laser with cylindrical lens and flow picture recording system. Instant simultaneous velocity vectors at whole field were measured by 2-D PIV system which adopted two¬frame grey-level cross correlation algorithm. Heat source was uniform heat flux(o.4W/cm$^2$, , O.8W/cm$^2$, 1.2W/cm$^2$). Obtained result showed various flow patterns such as kinetic energy distribution. Severe unsteady flow fluctuation within the cavity are remarkable and sheared mixing layer phenomena are also found at the region where inlet flow is collided with the counter-clockwise rotating main primary vortex. Photographs of Mach ~ Zehnder are also compared in terms of constant heat flux.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.407-412
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• 2000

In this study, a research for process design in bending of structural frame of AA6061-T6 with rubber pad was conducted. In this process, the conventional lower die made of metal is replaced with a polyurethane pad, resulting in high flexibility during bending. Vulcanized polyurethane rubber with shore A hardness of 60 was used for the pad. Experiments on a newly developed bending machine were carried out by controlling the stroke of the roller and horizontal movement of roller pad lower die. From this, the relation between roller path and geometry of the materials bent was obtained for the process design of producing roof rail part of a passenger car and the experimental result was compared with the target profile. For more accurate process design, it is required to control the roller path interactively. Based on the experience in developing the prototype bending machine, it is construed that a fully automated bending system with rubber pad to produce various light-weight components for automotive body frames can be successfully developed.