• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2003.11a
• /
• pp.54-58
• /
• 2003

In this study, the solution of Gel'fand-Levitan-Marchenko integral equation in the inverse scattering problem is efficiently solved for arbitrarily specified spectra pattern which are reflected from the restricted potential. The procedure is based on the successive approach without iterations. This method lessens the truncation errors which plague conventional design schemes using specific windows for reflection coefficients. It is shown that the method is adequate for the synthesis of the continuously varying one-dimensional potential of the nonuniformly distributed dielectric constants.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1295-1300
• /
• 2008

During the manufacturing and the service life of Au-Al wire bonded electronic packages, the ball bonds experience elevated temperatures and hence accelerated thermal diffusion reactions that promote the transformation of the Au-Al phases and the IMC growth. In this paper, the IC under high temperature storage (HTS) tests at $175^{\circ}C,\;200^{\circ}C$, and $250^{\circ}C$ are meticulously investigated. Thermal exposure resulted in the IMC growth, Kirkendall void and the crack of the Au-Al phases. The crack propagation occurs resulting in the failure of the Au-Al ball bonds. As the IC was exposed at the high temperature, decreased in the lifetime.

• ETRI Journal
• /
• v.37 no.3
• /
• pp.533-540
• /
• 2015

In wireless localization, several linear closed-form solution (LCS) methods have been investigated as a direct result of the drawbacks that plague the existing iterative methods, such as the local minimum problem and heavy computational burden. Among the known LCS methods, both the direct solution method and the difference of squared range measurements method are considered in this paper. These LCS methods do not have any of the aforementioned problems that occur in the existing iterative methods. However, each LCS method does have its own individual error property. In this paper, a hybrid LCS method is presented to reduce these errors. The hybrid LCS method integrates the two aforementioned LCS methods by using two check points that give important information on the probability of occurrence of each LCS's individual error. The results of several Monte Carlo simulations show that the proposed method has a good performance. The solutions provided by the proposed method are accurate and reliable. The solutions do not have serious errors such as those that occur in the conventional standalone LCS and iterative methods.

• Proceedings of the Korea Contents Association Conference
• /
• 2018.05a
• /
• pp.459-460
• /
• 2018

In this paper, we present a data augmentation method that generates synthetic plant disease images using Generative Adversarial Networks (GANs). We propose a training scheme that first uses classical data augmentation techniques to enlarge the training set and then further enlarges the data size and its diversity by applying GAN techniques for synthetic data augmentation. Our method is demonstrated on a limited dataset of 2789 images of tomato plant diseases (Gray mold, Canker, Leaf mold, Plague, Leaf miner, Whitefly etc.).

• Journal of the Korean Institute of Navigation
• /
• v.5 no.2
• /
• pp.41-47
• /
• 1981

Many new radar techniques have appeared on the electronic scene in recent years, such as a variety of automatic computer processing. However, even with the advent of these sophisticated radar techniques, an old problem continues to plague all radars: the problem of transmission line losses. With the higher performance required today, the Waveguide testing and trouble-shooting techniques remain essentially unchanged in principle. This paper dealt with the rf pulse "Time-domain Reflectometry" to inspect radar wave-guide system and compared with the conventional methods. During the investigation, it was verified that the pulsed TDR for wave-guide is superior to the conventional methods; 1. Disassembling is not needed to locate the discontinity points and measure the reflections of trobled points. 2. The results of the data are more precise. 3. The condition of individual component is able to the photographed and recorded permanently. 4. Since rf pulse TDR is based on the well-known basic radar principle, such a test set requires the minimum of training to operate. With the level of transmission line problems, the prospect of increasing complexity of equipment, and no relief in sight, the benifits must be emphasizied to adopt such a testing procedure.procedure.

• Acta Via Serica
• /
• v.8 no.2
• /
• pp.53-78
• /
• 2023

The paper presents some new results illustrating some developments related to the concept of the Silk Road and subsequent methodological reflections. New laboratory results of scientific analyses of plants, minerals, and human remains in combination with more conventional methods of research contribute to a better understanding of the multidirectionality of exchanges in Pre- and Protohistory. Unsuspected long-distance transfers of items, especially of metals (tin) and biological materials (plants, pathogens, etc.) are discovered. Adding ancient DNA and petroglyphs to the vexed question of the Indo-European migrations across Eurasia complexifies the familiar linguistic, historical, and archaeological research landscape. Recent excavations show the impact of the adoption of artistic elements adapted from the Achaemenid arts, far in the steppe world, and up to China. Multidirectional (including North-South lanes) and multidisciplinary approaches leave space and hope for more rigorous scientific modelizations for the archaeology of Eurasia and the Silk Road.

• Journal of Preventive Medicine and Public Health
• /
• v.31 no.3 s.62
• /
• pp.540-563
• /
• 1998

This Study has been carried out to make a recommendation for the next amendment of the Infectious Disease Prevention Act with a specific focus on the kind of notifyable disease. Korean, Japanese, German, U.S, English and French acts on infectious diseases prevention were reviewed, compared with and analized in regards of numbers and kinds of notifyable infectious diseases and their tendency of amendments. An criteria was designed to assess the level of validity of diseases to be designated in the act. Four items, the fatality (greater than 10% or not), the possibility to make a big epidemic, the availability of efficient vaccination and the usefulness of isolation, are used in the assessment. This index is applied to the diseases in Korean and other countries' Infectious Disease Prevention Acts. Results are as follows: 1. The Korean Infectious Disease Preventon Act has a unique way of classifying the notifyable infectious disease, that is, the first, the second and the third class. But the author cannot find the basis of classification. No other countries reviewed have the similar classification. 2. The ten diseases, cholera, plague, yellow fever, diphtheria, typhoid fever, poliomyelitis, rabies, tetanus, malaria, and meningococcal meningitis are designated as the notifyable diseases not only in Korea but also in Japan, Germany, United States, England and france. 3. Thirty seven diseases including small pox, Lassa fever, anthrax, influenza, German measles, Legionellosis, infection with E. coli O157:H7, Q-fever, brucellosis, Lyme disease are designated as legal disease at least one of the above mentioned countries. 4. The Korea has been coped with the change of the infectious disease occurrence for last fifty years in amendment of the Infectious Disease Prevention Act. 5. Japan has a special infectious surveillance system composed of 3,880 clinics throughout the whole country. 6. Germany has classified infectious diseases in five categories which are based on seriousness of disease. Any confirmed death, cases and suspected cases in class I should be reported within 24 hours. But only confirmed death and cases in class II, but not suspected cases, are reportable in Germarny. 7. Plague, bacillary dysentery, pertussis, mumps, Japanese encephaltis and Korean hemorrhagic fevers are diseases with high credits validity index among Korean legal disease. 8. German measles, anthrax, E. coli O157 : H7 infection, Lassa fever, Q-fever, brucellosis are high in validity index among those which are not designated in Korea but designated in other countries. In conclusion, the Korean Infectious Disease Prevention Act has well been coped with the changes of infectious disease occurrence for last fifty years, but the classification basis and the validity of diseases to be designated as legal diseases is worth reevaluating.

• Journal of the Korean Society of Radiology
• /
• v.7 no.6
• /
• pp.419-426
• /
• 2013

This study was performed in order to suggest the basic informations about the proper oral health babits for kindergarten children, through the investigation of the oral health survey and their oral haelth behaviors. 213 of kindergarten children age 6 were surveyed who has lived at Daegu city and the examined data were analysed by use of spss 18.0 ver.program. The children who had performed the toothbrushing for 3 or 4 times a day, were estimated as high level in voluntary under taking of toothbrushing. It revealed that the low of the caries experience rate in the group of the sabiects who performed toothbrushing at every after meals. On the other hands, both the caries experience index of children who had perfomed toothbrushing with the rolling method and the dental plague index of children who had performed the toothbrushing just the morning time of the oral examination day, wer reveealed as high scores, due to the lack of the abilities to perform the toothbrusing with the proper method. It was needed to educate children for practical performing the toothbrush as well as for traning it with the right way, in order to promote the oral health for kindergarten children.

• Korean Journal of Food Science and Technology
• /
• v.30 no.3
• /
• pp.702-708
• /
• 1998

The effects of mushrooms such as Lentinus edodes and Pleurotus ostreatus on anti-cancer activity through in vivo and in vitro experiments were powders of protein-bound polysaccharides in mushrooms were solubilized in 0, 5, 25 mg/kg saline, respectively and were used in vitro experiments. The in vivo experiments were carried out as followed: i) anti-cancer activities on Leukemia $(L_{1210})$, Hepatlicus cancer $(H_{22})$ and Sarcoma180/(S180), and ii) the effect on immune system through changes in intestine weight and the number of hemolytic plague forming cells. Protein-bound polysaccharides of all showed anti-cancer activity on $L_{1210}$ and fruit body of Lentinus edodes 25 mg/kg treatment group showed the highest inhibition rate (86%). Pleurotus ostreatus mycelial in medium of cultivate 25 mg/kg treatment. Fruid body of Lentinus edodes 25 mg/kg treatment group showed the highest inhibition rate (86% and 71%, respectively) on $H_{22}$ among them. The inhibition rates of fruit body and mycelial of Lentinus edodes 25 mg/kg treatment groups on S180 were 33.9% and 30.9%, respectively. Each samples of 50, 100, 200, $400\;{\mu}g/{\mu}L$ on in vitro cell toxicity test did not show significantly different cell death rates at P<0.05. In immune test, weights of liver and spleen were increased according to increase in conc. but were not significantly different at P<0.05. The weights of thymus were heavy in fruit body and mycelial of Lentinus edodes treatment group but were not significantly different at P<0.05. Hemolytic plague forming cells with antibody formation capability were significantly high in fruit body and mycelial of Lentinus edodes treatment samples.

• Applied Biological Chemistry
• /
• v.51 no.1
• /
• pp.84-87
• /
• 2008

In this research, we screened for glucosyltransferase (GTase) inhibitors that effectively prevent the dental caries from 420 kinds of boiled water extracts of herbs and wild plants and searched for GTase inhibitory activities. Among them, 13 kinds of hot water extracts had high GTase inhibitory activities and especially, we focused on Foeniculum vulgare which showed the highest inhibitory activity on GTase. The boiled water extract of F. vulgare was stable at high temperature and showed as a mixed type of competitive and uncompetitive inhibition kinetic behavior. It did not have antibacterial effect on Streptococcus mutans and had inhibitory activity on GTase. Specially, in the clinical trial, the group treated by boiled water extract of F. vulgare showed more decrease of plague index at 4.8 point than untreated group. These results suggested that boiled water extract of F. vulgare can effectively suppress the plague formation as it inhibits the GTase activity.