• Journal of electromagnetic engineering and science
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• v.16 no.3
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• pp.169-181
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• 2016

This work presents a new method for enhancing the performance of a dual band Planer Inverted-F Antenna (PIFA) and its lumped equivalent circuit formulation. The performance of a PIFA in terms of return loss, bandwidth, gain, and efficiency is improved with the addition of the proposed open stub in the radiating element of the PIFA without disturbing the operating resonance frequencies of the antenna. In specific cases, various simulated and fabricated PIFA models illustrate that the return loss, bandwidth, gain, and efficiency values of antennas with longer optimum open stub lengths can be enhanced up to 4.6 dB, 17%, 1.8 dBi, and 12.4% respectively, when compared with models that do not have open stubs. The proposed open stub is small and does not interfere with the surrounding active modules; therefore, this method is extremely attractive from a practical implementation point of view. The second presented work is a simple procedure for the development of a lumped equivalent circuit model of a dual band PIFA using the rational approximation of its frequency domain response. In this method, the PIFA's measured frequency response is approximated to a rational function using a vector fitting technique and then electrical circuit parameters are extracted from it. The measured results show good agreement with the electrical circuit results. A correlation study between circuit elements and physical open stub lengths in various antenna models is also discussed in detail; this information could be useful for the enhancement of the performance of a PIFA as well as for its systematic design. The computed radiated power obtained using the electrical model is in agreement with the radiated power results obtained through the full wave electromagnetic simulations of the antenna models. The presented approach offers the advantage of saving computation time for full wave EM simulations. In addition, the electrical circuit depicting almost perfect characteristics for return loss and radiated power can be shared with antenna users without sharing the actual antenna structure in cases involving confidentiality limitations.

• Korean Journal of Medicinal Crop Science
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• v.15 no.3
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• pp.203-209
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• 2007

In order to promote utilization of the Yangha (Zinger mioga Rosc.) as functional food and natural spices, and 95.93%, from the dried one 7.63%, and from powder 9.81%, respectively. Crude protein content from the Yangha powder was 11.21%, and contents of crude fat, crude ash and crude fiber were 2.44%,10.78%, and 14.47%, respectively. Most of compositions from Yangha powder were higher than those from raw and the dried one, except fer water content. Antioxidative effect was investigated through Rancimat and DPPH methods. Oxidative stability of Yangha powder was the highest of4.21Al. Furthermore, the free radical scavenging activity of Yangha powder (76.61%) was higher than that of raw (49.35%) or the dried one (61.78%). Volatile flavor compounds of Yangha was extracted by steam distillation and extraction method. The extracts were analyzed and identified by gas chromatography and GC-MS spectrometry. One hundred twenty two volatile flavor components were identified, and the major component was terpene compounds including ${\alpha}$-pinene, ${\beta}$-pinene, ${\beta}$-phellandrene, 1,4-terpineol, and ${\beta}$-terpinene.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.136-142
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• 2006

Haematococcus pluvialis is a great producer of astaxanthin (3,3'-dihydroxy-$\beta$,$\beta$-carotene-4,4'-dione). The activities of astaxanthin include potential cancer prevention, immune response enhancement, antioxidant activity, and so on. Nevertheless, it tried to manipulate by mutation for overcoming low growth rate of wild type and limited production of astaxanthin. Mutated colony that is lager and more reddish one than wild type was selected by attempting to expose strains to UV irradiation and to treat chemical such as EMS and colchicines as mutagen. Selected mutants were further screened using inhibitors of the carotenoid biosynthetic pathway. Inhibitors used were nicotine and diphenylamine and both had decreased the survival rate by 40-50%. Among over 50,000 mutant colonies screened, two strains were selected. One selected mutant strain (U15-5) from UV treatment showed 1.68-fold higher total carotenoid contents per cell than that of the wild type strain. On the other hand, the other selected mutant strains (DS, M4-3) from colchicine treatment showed 20$\sim$30% faster cell growth than the wild type strain.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.255-261
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• 2013

This study investigated changes in the physicochemical characteristics and coffee flavors of coffee beans under different roasting conditions. Four different kinds of roasted coffees were analyzed using a headspace gas chromatographic technique. The moisture content and total acidity of roasted coffee decreased whereas the pH and weight loss (%) increased, as coffee beans were roasted at higher temperatures. The Hunter's color values of the roasted coffee (indicating L (lightness) and b (yellowness)) decreased as the roasting temperature of the coffee beans increased, but a (redness) value only increased with light roasting. We also noted that the color of the Arabica coffee was darker than that of the Robusta coffee. The aroma compounds, acetaldehyde, acetone, 2-methylfuran, 2-methylbutanol, 2-methylpyrazine, furfural, 2-propanone, furfuryl alcohol, 2,5-dimethylpyrazine and furfuryl acetate were mainly analyzed. A sensory evaluation of all light-roasted coffees had flavor and sourness and those of all medium-roasted coffees had heaviness and finishness.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.9
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• pp.661-667
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• 2018

Tactical communication radio systems that employ software defined radios(SDRs) have been developed for achieving high-speed data transmissions and voice communications. Such systems possess multiband and multichannel features, and can potentially replace several existing radio systems. This paper proposes a design for wideband antennas by incorporating a diplexer matching network for tactical vehicles. The proposed antenna design includes two radiators(upper and lower) and a diplexer matching network connected to the end of the feed line such that the LC matching networks are interleaved in the lower radiator and spring mount. By employing the diplexer matching network, the designed antenna can perform wideband impedance matching for the fifty ohm feed line. The designed LC networks aid in varying the effective electrical length of the antenna according to the operation frequency. The primary objective behind adjusting the electrical length is to vary the current distribution above and below the LC networks. The proposed antenna was fabricated and tested in an open site. The obtained evaluation results show that the designed antenna can achieve a relative bandwidth of 190% with a VSWR value of 3.5:1, and can attain good antenna gains over VHF and UHF bands.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1221-1233
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• 2016

Purpose: To investigate any potential association between wine and breast cancer risk. Materials and Methods: We quantitatively assessed associations by conducting a meta-analysis based on evidence from observational studies. In May 2014, we performed electronic searches in PubMed, EmBase and the Cochrane Library to identify studies examining the effect of wine drinking on breast cancer incidence. The relative risk (RR) or odds ratio (OR) were used to measure any such association. Results: The analysis was further stratified by confounding factors that could influence the results. A total of twenty-six studies (eight case-control and eighteen cohort studies) involving 21,149 cases were included in our meta-analysis. Our study demonstrated that wine drinking was associated with breast cancer risk. A 36% increase in breast cancer risk was observed across overall studies based on the highest versus lowest model, with a combined RR of 1.0059 (95%CI 0.97-1.05) in dose-response analysis. However, 5 g/d ethanol from wine seemed to have protective value from our non-linear model. Conclusions: Our findings indicate that wine drinking is associated with breast cancer risk in a dose-dependent manner. High consumption of wine contributes to breast cancer risk with protection exerted by low doses. Further investigations are needed for clarification.

• Geophysics and Geophysical Exploration
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• v.21 no.1
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• pp.15-25
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• 2018

Seismic inversion is a high-resolution tool to delineate the subsurface structures which may contain oil or gas. On the other hand, marine controlled-source electromagnetic (mCSEM) inversion can be a direct tool to indicate hydrocarbon. Thus, the joint inversion using both EM and seismic data together not only reduces the uncertainties but also takes advantage of both data simultaneously. In this paper, we have developed a simultaneous joint inversion approach for the direct estimation of reservoir petrophysical parameters, by linking electromagnetic and seismic data through rock physics model. A cross-gradient constraint is used to enhance the resolution of the inversion image and the maximum likelihood principle is applied to the relative weighting factor which controls the balance between two disparate data. By applying the developed algorithm to the synthetic model simulating the simplified gas field, we could confirm that the high-resolution images of petrophysical parameters can be obtained. However, from the other test using the synthetic model simulating an anticline reservoir, we noticed that the joint inversion produced different images depending on the model constraint used. Therefore, we modified the algorithm which has different model weighting matrix depending on the type of model parameters. Smoothness constraint and Marquardt-Levenberg constraint were applied to the water-saturation and porosity, respectively. When the improved algorithm is applied to the anticline model again, reliable porosity and water-saturation of reservoir were obtained. The inversion results indicate that the developed joint inversion algorithm can be contributed to the calculation of the accurate oil and gas reserves directly.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.3
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• pp.135-140
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• 1988

This field experiment was carried out to determine the effects of cutting times (3,4 and 5 times $yr^{-1}$) and cutting heights (3, 6 and 9 cm) on the growth and dry matter(DM) yield of grasses grown under pine trees, and botanical composition of woodland pasture. The conditions of the experimental field was south direction with 30% of shade (ca. 70% of full sunlight). Annual DM yield was higher in the plots cut 4 times (6,097 kg) and 3 times (5,953 kg) than in 5 times (5,305 kg $ha^{-1}$). However, it ip considered that total nutrient yields may be not different among 3 treatments. The yield was significantly (P < 0.05) increased with higher cutting height, regardless of cutting time. The 9 cm of stubble height was very effective on both increasing DM production and seasonal distribution of DM. In botanical composition, 3 cm and 6 cm of cutting height accelerated the percentages of bareland and weeds, regardless of cutting time, particularly in summer season. However, 9 cm of stubble height maintained 80-85% of pasture grasses in all cutting times. In this experiment, therefore, cutting height was more important factor than annual cutting times for forage production and pasture longevity, and it is desirable to harvest 4-5 times per year (under this experimental field condition) with 9 cm of stubble height on woodland pasture.

• Applied Microscopy
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• v.12 no.2
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• pp.55-68
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• 1982

The study on the nerve cells in the pars intercerebralis(IP) of 5-day-old cabbage butterfly Pieris rapae L. was performed to observe their ultrastructures and classify them on the basis. of the differences in size, shape and relative distribution cf cell organelles. The brain-subesophageal ganglion complex was fixed in 1% paraformaldehyde-1% gluaraldehyde mixture and embedded in araldite mixture. The transverse thin sections of IP were stained with uranyl acetate and lead citrate and examined by Hitachi 500 and ]EM 100B electron microscope. Five distinct types. of nerve cells are recognized and are arbitrarily designated as Type I, Type II Type III, Type IV and Type V. Type I neurone: These neurones are neurosecretory cells. Several neurosecretory cells are. recognized in the pars intercerebralis. They are roughly round or peach-shaped cells measuring $13{\sim}25{\mu}m$ in diameter. The rounded nucleus shows about $5{\sim}10{\mu}m$ in diameter. The chromatin is predominantly diffused with only occasional dense patches. The perikaryon contains numerous. mitochondria, free polyribosomes and neurosecretory granules. The neurosecretory granules are relatively uniform in electron density, and each one is about $100{\sim}400{\mu}m$ in diameter and surrounded by a single membrane. The granules are also observed mostly as in groups. In one group of neurones the cisternae of endoplasmic reticulum are distended or in other group of neurones are not distended. Golgi saccules are slightly dilated at their lateral extremities and contains. frequenty dense rounded materials. Type II neurone: Thes have the largest soma in the pars intercerebralis about $30{\sim}35{\mu}m$ in diameter. They also show roughly polygonal in shape. The nucleus is elongated or sickle-shaped. The chromatin is mainly in the euchromatin form. The perikarya in these cells are well populated with populated with free ribosomes and contain numerous mitochondria and Golgi bodies. The cisternae of granular endoplasmic reticulum are also well distributed. Type III neurone: They are oval or spindle-shaped and also medium-sized. neurones approximately $15{\sim}17{\mu}m$ in length. The nucleus is oval or slightly elongated in shape and $8{\sim}9{\mu}m$ in length. The chromatin occurs in diffused form. The cytoplasm contains many filamentous or oval mitochondria. The perikaryon has also numerous free polyribosomes and cisternae of granular endoplasmic reticulum. Type VI neurone: They are roughly polygonal in shape probably due to the close approximation of the adjacent cells. The soma is about $7{\sim}8{\mu}m$ in diameter. The nucleus is round or oval in shape and $5.0{\sim}5.8{\mu}m$ in diameter. The necleus also occupies a large proprion of the cell body. The perikaryon is well populated with free ribosomes and contains several mitochondria and cistenae of granular endoplasmic reticulum. Type V neurone: These neurones are similar to Type VI neurones in various respects such as cell size and cell inclusion, but they differ from Type IV neurones in shape. The soma is oval or slightly elongated. The cell body contains several filamentous and oval mitochondria.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.341-353
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• 2020

In accordance with the implementation of the Positive List System (PLS), the proper usage of pesticides is now being enforced. It is assumed that unregistered pesticides are being used on agroforestry products due to the low number of registered pesticides in the agricultural industry. In this study, pesticide and heavy metal residues were investigated in 13 types of products to determine the status of usage. The levels (%) of pesticides detected in Pimpinella beachscape, Platycodon grandiflorum, Codonopsis lancekolate, Artemisia dubia, Angelica gigas, Pyrus pyrifolia, and Punica granatum were 40.0, 20.0, 26.7, 13.3, 56.3, 57.1, 33.3, 26.7, 66.7, and 46.7%, respectively, while, those in Petridium aquilinum, Disoscorea batata and Senna tora were zero. Heavy metals (Pb, Cd) were detected only from P. grandisflorum and A. dubia. The pesticide usage and registration data by agroforestry product obtained in the study will be useful in the future for ensuring the safety of domestic agroforestry products.