• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.20 no.9
• /
• pp.883-889
• /
• 2009

Since the SRRs(Short Range Radar) load on the GVESs(Ground Vehicle Equipment System) are operated within several hundred meters, it is important to suppress the interferences between the SRRs. These interference are reduced using the frequency separation between channels, however this method isn't a perfect solution owing to a difficulty of a realization for the interference suppression. Thus, a pulse-to-pulse coding used to suppress the interference fundamentally is proposed in this paper. The concept, the application method and the test results of the proposed method have been described in this paper.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.21 no.3
• /
• pp.306-314
• /
• 2018

In maritime environment, it is necessary to understand the characteristics of sunglint since it may degrade the target detection performance of the infrared sensor mounted weapons. In this paper, sunglint in LWIR band is modeled using the slope distribution of the sea surface, and is verified by comparing the radiance of a simulated result with that of the real world. According to the simulation, sunglint is critical when the solar zenith angle is over $60^{\circ}$. The peak radiance of sunglint grows as the solar zenith angle increases until it reaches $83^{\circ}$ and has a large difference depending on the solar zenith angle when the wind speed is small. Finally, seasonal and temporal characteristics of sunglint effects are analyzed. In summer, sunglint is dominant in the horizon near the solar azimuth right after sunrise and before sunset. However, in winter, the influence of sunglint lasts even during the daytime since the elevation of the sun is much lower than in summer.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.3
• /
• pp.612-621
• /
• 1996

In this paper, we propose the low sidelobe digital FIR doppler filter bank synthesis algorithm through the Gradient Descent method and it can be practially appliable to coherent pulse doppler radar signal processing. This algorithm shows the appropriate calculation of tap coefficients or zeros for FIR transversal fiter which has been employed in radar signal processor. The span of the filters in the filter bank be selected at the desired position the designer want to locate, and the lower sidelobe level that has equal ripple property is achieved than one for which the conventional weithtedwindow is used. Especially, when we implemented filter zeros as design parameters it is possible to make null filter gain at zero frequency intensionally that would be very efficient for the eliminatio of ground clutter. For the example of 10 tap filter synthesis, when filter coefficients or zeros are selected as design parameters the corresponding sidelobelevel is reducedto -70db or -100db respectively and it has good convergent characteristics to the desired sidelobe reference value. The accuracy ofapproach to the reference value and the speed of convergence that show the performance measure of this algorithm are tuned out with some superiority and the fact that the bandwidth of filter appears small with respect to one which is made by conventional weighted window method is convinced. Since the filter which is synthesized by this algorithm can remove the clutter without loss of target signal it strongly contributes performance improvement with which detection capability would be concerned.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.10
• /
• pp.1350-1358
• /
• 2012

Viral pathogens, alongside other pathogens, have major effects on crustacean aquaculture. Hepatopancreatic parvovirus (HPV) is an emerging virus in the shrimp industry and has been detected in shrimp farms worldwide. The HPV genome has greater diversity than other shrimp viruses owing to its wide host range and geographical distribution. Therefore, developing diagnostic tools is essential to detect even small copy numbers from the target region of native HPV isolates. We have developed two easy to use quantitative real-time PCR kits, called Green Star and Dual Star, which contain all of the necessary components for real-time PCR, including HPV primers, using the primers obtained from the sequences of HPV isolates from Korea, and analyzed their specificity, efficiency, and reproducibility. These two kits could detect from 1 to $1{\times}10^9$ copies of cloned HPV DNA. The minimum detection limits obtained from HPV-infected shrimp were $7.74{\times}10^1$ and $9.06{\times}10^1$ copies in the Green Star and Dual Star assay kits, respectively. These kits can be used for rapid, sensitive, and efficient screening for HPV isolates from Korea before the introduction of postlarval stages into culture ponds, thereby decreasing the incidence of early development of the disease.

• Journal of Information Processing Systems
• /
• v.19 no.4
• /
• pp.527-539
• /
• 2023

In the positioning algorithm of two-dimensional planar sensor array, the estimation error of time difference-ofarrival (TDOA) algorithm is difficult to avoid. Thus, how to achieve accurate positioning is a key problem of the positioning technology based on planar array. In this paper, a method of sensor reliability discrimination is proposed, which is the foundation for selecting positioning sensors with small error and excellent performance, simplifying algorithm, and improving positioning accuracy. Then, a positioning model is established. The estimation characteristics of the least square method are fully utilized to calculate and fuse the positioning results, and the non-uniform weighting method is used to correct the weighting factors. It effectively handles the decreased positioning accuracy due to measurement errors, and ensures that the algorithm performance is improved significantly. Finally, the characteristics of the improved algorithm are compared with those of other algorithms. The experiment data demonstrate that the algorithm is better than the standard least square method and can improve the positioning accuracy effectively, which is suitable for vibration detection with large noise interference.

• Journal of Korean Society for Atmospheric Environment
• /
• v.30 no.1
• /
• pp.77-87
• /
• 2014

In this study, an experimental approach to measure a suite of low weight hydrocarbons was investigated with an emphasis on ethylene (EL) along with many others (ethane (EA), propane (PA), propylene (PL), n-butane (BA), acetylene (AL), methyl acetylene (ML)). Their concentrations were quantified using GC-FID system equipped with thermal desorption (TD) system. The TD-based analysis was conducted using both Link Tube/Thermal Desorber (LT/TD) method and Modified Injection through a Thermal Desorption (MITD) method. The results of these analyses were evaluated in a number of respects. The system allowed the detection of all compounds except methane with the mean response factor (RF) of 10.28 (EA) to 11.94 (PL). The method detection limits of target compounds were seen in the range of 0.027 (ML) to 0.146 ng (BA). The emission flux of some environmental samples (fruits), when measured using a small flux chamber system, fell in the range of 0.14 (AL: Kiwi) to $181ng{\cdot}g^{-1}{\cdot}hr^{-1}$ (EL: Apple Peel). The results of this study confirm that the experimental approach developed in this study allows to accurately measure emissions of low weight hydrocarbons (LWHC) like ethylene from various natural and man-made source processes.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2005.05a
• /
• pp.215-220
• /
• 2005

In order to apply to land mine detection effectively, GPR using an optical electric field sensor as a receiver has been developed. The optical electric field sensor is very small and uses optical fiber instead of metallic coaxial cable. With the combination of these advantages and the bistatic radar system, it can be possible for an operator to measure quite flexible and safely. The sensor has been tested in stepped frequency radar system with frequency which consists of a vector network analyzer, a fixed double ridged horn antenna as transmitter. For considering effectiveness in real field, we applied impulse radar system, which consist of a digital oscilloscope and a impulse generator to produce the impulse. Detection of a PMN2 mine model was carried out by the impulse radar system at a sand pit. The PMN2 were detected clearly with sufficiently high resolution, the target contrast was almost the same while the scanning time decreased down to 1/100.

• Advances in nano research
• /
• v.15 no.5
• /
• pp.451-466
• /
• 2023

Gastrointestinal cancer (GC) is a prevalent malignant tumor of the digestive system that poses a severe health risk to humans. Due to the specific organ structure of the gastrointestinal system, both endoscopic and MRI diagnoses of GIC have limited sensitivity. The primary factors influencing curative efficacy in GIC patients are drug inefficacy and high recurrence rates in surgical and pharmacological therapy. Due to its unique optical features, good biocompatibility, surface effects, and small size effects, nanotechnology is a developing and advanced area of study for the detection and treatment of cancer. Because of its deep location and complex surgery, diagnosing and treating gastrointestinal cancer is very difficult. The early diagnosis and urgent treatment of gastrointestinal illness are enabled by nanotechnology. As diagnostic and therapeutic tools, nanoparticles directly target tumor cells, allowing their detection and removal. XGBoost was used as a classification method known for achieving numerous winning solutions in data analysis competitions, to capture nonlinear relations among many input variables and outcomes using the boosting approach to machine learning. The research sample included 300 GC patients, comprising 190 males (72.2% of the sample) and 110 women (27.8%). Using convolutional neural networks (CNN) and artificial neural networks (ANN)-EXtreme Gradient Boosting (XGBoost), the patients mean± SD age was 50.42 ± 13.06. High-risk behaviors (P = 0.070), age at diagnosis (P = 0.037), distant metastasis (P = 0.004), and tumor stage (P = 0.015) were shown to have a statistically significant link with GC patient survival. AUC was 0.92, sensitivity was 81.5%, specificity was 90.5%, and accuracy was 84.7 when analyzing stomach picture.

• Analytical Science and Technology
• /
• v.18 no.4
• /
• pp.344-354
• /
• 2005

This study was carried out to evaluate the performance of a small chamber sampling and analytical method for the measurement of total volatile organic compounds (TVOC) and formaldehyde (HCHO) emission from building materials. While VOC was determined by the adsorbent tube sampling and sequential thermal desorption coupled with GC/MSD analysis, formaldehyde sampled with DNPH-silica cartridge was analyzed by HPLC. Wide-range performance criteria such as repeatability, desorption efficiency, emission chamber recovery test, duplicate precision, breakthrough volume and method detection limits were investigated for the evaluation of small chamber method. The overall precision of the small chamber sampling and analytical methods was estimated within 20~30% for target compounds. In conclusion, this study demonstrated that the small chamber sampling and analytical method can be reliably applied for the measurement of building materials pollutants.

• Parasites, Hosts and Diseases
• /
• v.56 no.1
• /
• pp.87-91
• /
• 2018

Morphological and molecular characteristics of spirometrid tapeworms, Spirometra decipiens, were studied, which were recovered from a heavily infected stray cat road-killed in Eumseong-gun, Chungcheongbuk-do (Province), the Republic of Korea (=Korea). A total of 134 scolices and many broken immature and mature proglottids of Spirometra tapeworms were collected from the small intestine of the cat. Morphological observations were based on 116 specimens. The scolex was 22.8-32.6 mm (27.4 mm in average) in length and small spoon-shape with 2 distinct bothria. The uterus was coiled 3-4 times, the end of the uterus was ball-shaped, and the vaginal aperture shaped as a crescent moon was closer to the cirrus aperture than to the uterine aperture. PCR amplification and direct sequencing of the cox1 target fragment (377 bp in length and corresponding to positions 769-1,146 bp of the cox1 gene) were performed using total genomic DNA extracted from 134 specimens. The cox1 sequences (377 bp) of the specimens showed 99.0% similarity to the reference sequence of S. decipiens and 89.3% similarity to the reference sequence of S. erinaceieuropaei. In the present study, we report a stray cat heavily infected with S. decipiens identified by mitochondrial cox1 sequence analysis and morphological examinations of the adult worms.