• ETRI Journal
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• v.31 no.5
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• pp.616-618
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• 2009

In this letter, a novel hybrid planar inverted-F antenna (PIFA) with a T-shaped slot on the ground plane is proposed. The loop structure formed by the feed line and shorting pin can be operated as a series and shunt inductance for the PIFA and the T-shaped slot antenna, respectively. The PIFA operates at a frequency of 1.75 GHz, while the T-shaped slot on the ground plane operates at 2.4 GHz by the same voltage feeding source. The height of the PIFA is 6.5 mm, and the size of an upper patch is designed to be 30 mm${\times}$16 mm. The measured relative impedance bandwidth of the PIFA and the T-shaped slot are about 12% and 21%, respectively. In addition, good antenna performance was achieved.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.259-264
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• 2005

In this paper, a novel compact microstrip-fed antenna with band-rejection characteristic for wideband applications is proposed. By cutting an L-shaped notch on the radiation patch, the wideband property for the proposed antenna is achieved. In addition, a C-shaped slot is introduced to obtain the band rejection operation of the antenna. The antenna, with very small size of $15.5\times21 mm^2$ including the ground plane, operates over 3.08 to 10.97 GHz and has the rejection band of 5.03 to 5.91 GHz for $S_{11}$ < -10 dB.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.601-605
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• 2007

This paper describes the experimental method to monitor the structural integrity. The crack on structures changes the wave propagation characteristics of structures. To monitor this change, frequency dependent variation of dynamic stiffness of beam structures is obtained by using beam transfer function method, and its trends are compared to undamaged one for identifying the location and size of the crack. Piezoelectric actuators were used to generate flexural vibrations. It eliminated various restrictions of continuously measuring wave propagation characteristics and monitoring structural integrity. The structural integrity was identified with minimal number of measurements and smart structures employing PZT actuations.

• Journal of Chest Surgery
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• v.22 no.4
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• pp.630-637
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• 1989

Author studied 30 cases of remained heart murmur patients after VSD repair. The age ranged from 7months to 27 years, and sex ratio was 29: 1 in male and female. Perimembranous trabecular type of VSD was the most common causes of remained murmur after operation 11 cases, and the next was subpulmonic type 9 cases. The VSD size between 1.1 and 2.0cm in diameter was the most common in 15 cases. The operative method frequently used was patch closure in 21 cases, and commonly used surgical approaching way was through right atrium. Mechanisms of origin of postoperative remained murmur was from TR 9 cases, PI 6 cases, PS 5 cases, remnant shunts 5 cases, pulmonary artery dilatation 2 cases, MR 2 cases, and subaortic stenosis 1 cases.

• Journal of Chest Surgery
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• v.28 no.11
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• pp.1045-1048
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• 1995

Pulmonary atresia with VSD is uncommon congenital anomaly with high mortality in neonatal period.Recently we experienced surgical correction of pulmonary atresia with VSD. The case was 2 month old male patient diagnosed as pulmonary atresia with VSD and PDA. Atretic pulmonary artery segment from Rt ventricular infundibulum to pulmonary artery was lcm in length. The pulmonary trunk tapered toward Right ventricular infundibulum and resulted in blind pouch with diameter of lmm. The left pulmonary artery was stenosed at just proximal and distal part to which PDA was connected. Total correction was undertaken which consisted of PDA ligation, dacron patch closure of VSD, establishment of continuity between right ventricle and pulmonary artery with autogenous pericardium. Postoperative systolic fight ventricular pressure and left ventricular pressure ratio was 0.7. In patient with pulmonary atresia with VSD it is advisable to perform a corrective operation, whenever the size and anatomy of pulmonary artery are acceptable for it.

• Journal of information and communication convergence engineering
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• v.14 no.2
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• pp.129-135
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• 2016

In this paper, we present a novel algorithm for image-based maritime obstacle detection using global sparsity potentials (GSPs), in which "global" refers to the entire sea area. The horizon line is detected first to segment the sea area as the region of interest (ROI). Considering the geometric relationship between the camera and the sea surface, variable-size image windows are adopted to sample patches in the ROI. Then, each patch is represented by its texture feature, and its average distance to all the other patches is taken as the value of its GSP. Thereafter, patches with a smaller GSP are clustered as the sea surface, and patches with a higher GSP are taken as the obstacle candidates. Finally, the candidates far from the mean feature of the sea surface are selected and aggregated as the obstacles. Experimental results verify that the proposed approach is highly accurate as compared to other methods, such as the traditional feature space reclustering method and a state-of-the-art saliency detection method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.315-318
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• 2007

Non-Destructive Health Monitoring using PZT sensors is a major concern and has great significance for research about NDT (Non-Destructive Test). In this paper, we study about the guided wave measurement method using PZT sensors to find cracks and estimate locations. Two aluminum beams bonded with PZT sensors were tested for estimating about the guided wave propagation characteristics and shape of each beam are decided in terms of analytical purpose. NI Signal Acquisition Device and specially designed LabVIEW VI program were used for data acquisition and analysis. The measured data were progressed by using a high-pass filtering.

• Korean Journal of Environmental Biology
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• v.21 no.4
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• pp.337-341
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• 2003

Habitat heterogeneity can enhance biological diversity by providing variation in structural diversity. This paper reviewed heterogeneous habitat serves as a population stability and superior demographic performance (e.g., high density, survivorship, reproductive rate) can be observed compared with organisms with inferior demographic performance. The idea of habitat variation has been further developed in modelling. Furthermore the size and configuration (distribution) of a patch (of a particular habitat type) become effective for the stability of population through hiding places and food resources. Species diversity is related to habitat complexity that provides structural diversity to ground -dwelling organisms. Finally coarse woody debris can enhance habitat complexity thus stabilizing population fluctuation and increasing survivorship.

• Journal of Satellite, Information and Communications
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• v.11 no.1
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• pp.37-40
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• 2016

We designed an antenna structure with the circular polarization metamaterial superstrate which increases the directivity of the primary antenna as a lens. The metamaterial superstrate removes the necessity of the array antenna and complicated feed. Plus, it provides the Fabry-perot cavity with the circular polarization. With regard to the primary antenna, a CRLH antenna is adopted to have the size-reduction from the conventional half-wavelength patch antenna.

• Journal of Chest Surgery
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• v.10 no.1
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• pp.143-147
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• 1977

Atrial septal defect is the most common of the congenital heart disease in the adult. Since the first description of atrial septal defect by Rokitansky in 1857, this anomaly has been studied by many workers in past one century. In 1953, Lewis had first corrected the atrial septal defect under direct vision with deep hypothermia, and Gibbon [1954] had first done the atrial septal defect under direct vision with extracorporeal circulation. In our college [May 2’ 1977], we have first repaired the A.S.D. under direct vision with artificial heart-lung machine and, the defect was 4x5cm in size which was closed by Dacron patch. This patient was 12 year old girl who is well now. [postoperative 13 days]