• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.219-222
• /
• 2004

There are several factors that disturb an Ultra-Wideband (UWB) radio propagation in an indoor environment such as path loss, shadowing and multipath fading. These factors directly affect the quality of the received signal. In this paper, we investigated the influence of the human body shadowing on UWB propagation based on measured wireless channel in an anechoic chamber. The characteristics of the UWB channel including the transmitter and the receiver antenna effects are acquired over the frequency bandwidth of 3${\sim}$11 GHz. The major factors such as the power delay profile (PDP), the angular power distribution (APD), the pulse distortion and the RMS delay spread caused by the human body shadowing are presented.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39C no.11
• /
• pp.1209-1215
• /
• 2014

The Uniform Geometrical Theory of Diffraction(UTD) is an effective technique to analyze the radio wave by ray-based calculation of the diffraction coefficient and the reflection coefficient. In this paper, user body shadowing based on the UTD is investigated when the user is close to the mobile device. Two cases are introduced. One is that the user is calling with the mobile attached to the ear(Head Model). The other is that the mobile is located about 15cm away from the user's chest(Chest Model) Radiation Model and Scattering Model are applied to these cases presenting which model is applicable.

• Journal of Veterinary Clinics
• /
• v.28 no.1
• /
• pp.94-100
• /
• 2011

This study was performed to describe the radiographic and ultrasonographic features of retained surgical gauze known as gossypiboma in 9 dogs. Female dogs (n = 8) were at higher risk and seven out of the eight cases had a history of ovariohysterectomy. Seven dogs were symptomatic and the most common clinical signs were vomiting, anorexia, and inertia. A palpable abdominal mass was detected in six dogs. Radiographic signs included a localized abdominal mass with soft tissue density (n = 7) or a mass containing speckled gas (n = 1). Ultrasonography showed a hypoechoic mass with a hyperechoic center (n = 4), or a homogeneous hypoechoic mass (n = 3). The remaining dogs (n = 2) showed an intestinal wall surrounding a hyperechoic center. Regardless of the characteristics of a mass, an acoustic shadowing was accompanied from the center of a mass in all dogs. Ultrasonography also revealed complications such as adhesion between a mass and adjacent organs, and peritonitis and intestinal obstruction around a mass. The gossypiboma can be considered when a hypoechoic mass accompanying a hyperechoic center with acoustic shadowing is observed on ultrasound examination.

• Journal of Veterinary Clinics
• /
• v.31 no.4
• /
• pp.333-336
• /
• 2014

An 1-year-old, intact female Yorkshire Terrier weighing 1.83 kg was referred for vomiting and anorexia. Survey abdominal radiographs revealed marked gastric distention. Ultrasonography showed a hyperechoic material with acoustic shadowing near the pylorus. A foreign body and ulceration were identified during gastroscopic examination. After endoscopic retrieval of gastric foreign body, unexpectedly abdominal distention was developed. Abdominal radiographs revealed pneumoperitoneum, but no leakage of contrast media was observed in gastrointestinal contrast study. Three days after hospitalization with supportive care, no abnormal findings were detected, and then the dog was discharged. This case describes the development of peumoperitoneum during endoscopic retrieval of gastric foreign body.

• Journal of Communications and Networks
• /
• v.8 no.3
• /
• pp.286-289
• /
• 2006

Measurement results are presented for the effects of people moving near and across short-range indoor propagation links at 2.45 GHz (ISM band). Excess loss due to scattering and blockage by human bodies in the vicinity of one terminal were measured for different radio links in an office environment. Statistics on fades due to human body motion are given. Polarization coupling (depolarization) for various radio links was measured, and correlation of polarization components is discussed as a basis for using polarization diversity reception in short-range indoor systems.

• The Research Journal of the Costume Culture
• /
• v.20 no.1
• /
• pp.49-61
• /
• 2012

This study focuses on looking at the influence of silhouette in the 1930s on fabric pattern design by comprehending how differently flower-pattern design were found according to clothing silhouette. The period scope of research was limited to 1930s, and the research object was set as the flower patterns seen in the designer's high-fashion and the women's daily apparel as well as the clothes for sports and leisure activities. Based on the above research scope, the researcher investigated the clothing silhouette and the textile patterns in 1930s by reviewing the literature about domestic and foreign books, research papers, domestic and foreign fashion magazines, information on the Internet. A glance at the women's clothing in the 1930s reveals that they emphasized something inactive, elegant, feminine and that great popularity was given to feminine silhouette that closely fitted the body and long and slim, as skirts became longer and longer. Like this, silhouette refused traditional methods in the technique of expressing flower patterns that were on-trend in that period, pursued the freedom of line and form, used shadowing technique by means of free pens and brushes and the effect of watercolors. It also arranged in a semitransparent way and painted contours alone, too. Flower patterns fell into two categories: amorphous abstract patterns and standardized abstract patterns. The patterns expressed themselves, divided into small-scale irregular patterns and abstract geometric patterns that filled the entire textile.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.10
• /
• pp.633-639
• /
• 2018

High-resolution images using remote sensing (RS) is importance to secure for spatial classification depending on the characteristics of the complex and various factors that make up the river environment. The purpose of this study is to evaluate the accuracy of the classification results and to suggest the possibility of applying the high resolution hyperspectral images obtained by using the drone to perform spatial classification. Hyperspectral images obtained from study area were reduced the dimensionality with PCA and MNF transformation to remove effects of noise. Spatial classification was performed by supervised classifications such as MLC(Maximum Likelihood Classification), SVM(Support Vector Machine) and SAM(Spectral Angle Mapping). In overall, the highest classification accuracy was showed when the MLC supervised classification was used by MNF transformed image. However, it was confirmed that the misclassification was mainly found in the boundary of some classes including water body and the shadowing area. The results of this study can be used as basic data for remote sensing using drone and hyperspectral sensor, and it is expected that it can be applied to a wider range of river environments through the development of additional algorithms.

• Journal of radiological science and technology
• /
• v.29 no.4
• /
• pp.267-274
• /
• 2006

The evaluation of GB stones with ultrasound has proved to be useful procedure in patient with symptoms of cholelithiasis. GB is evaluated for size, wall thickness, presence of internal reflections within the lumen and posterior acoustic shadowing or enhancement in Ultrsonography. The patient position should be shifted during procedure to demonstrate further the presence of stone within the GB. Patient scanned at the Rt. subcostal region in supine, right lateral, Lt. down decubitus, and upright sitting position. So GB stone should shift to dependent area of GB. Often, GB is not markedly distended in the presence of cholethiasis, and so the diagnosis becomes more difficult. One of the more difficult areas for detection of a GB stones are embeded in the cystic duct region. And since the GB is adjacent to the duodenum and hepatic flexure, its may be difficult to visualizing a GB stone. When patient study position changes frome supine to other position, stones displaced the site. But if its are polyps, not changes the site whatever patient positions. It is very important to what make different GB stones or polyps. We have studied about mobility of GB stones according to the patients position(supine, Lt. down decubitus, $30^{\circ} LAO. sitting and hand-knee). So we have a result, stones wherever localized within the GB, changed 100% its position in the hand-knee position and the others appeared at least 90%. In this study, when a large stones are located through fundus-body and body-neck, does not changing the stones position in spite of varied patient's positions. But hand-knee positions can identified GB stones, because its make changed the position of stons from posterior wall to anterior wall within the GB. We recommend the hand-knee position for differentiation GB stones from polyps.