• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.6
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• pp.738-749
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• 2016

To understand the characteristics of the spatio-temporal distribution of phytoplankton after barrage construction in the Nakdong River Estuary, this study investigated relevant environmental parameters and phytoplankton status based on bi-monthly samples collected from the Nakdong River Estuary itself from February 2013 to December 2015. Environmental parameters did not differ significantly across these years but did vary between zones and seasons. The results suggested that the upper zone was dominated by fresh-water diatoms, green algae, and blue-green algae, whereas the lower zone was mostly dominated by dinoflagellates. The presence of Stephanodiscus spp., Asterionellopsis formosa, and Microcystis spp. in the upper zone was related to the inflow of freshwater discharge by artificial control of dyke gates. The dominant phytoplankton species in this zone were dependent on temperature, wind speed, DIP, and DIN, while those in the lower zone were mostly dependent on nutrients and wind speed. In addition, at the lower zone, there were negative correlations between Prorocentrum donghaiense, DIN, and wind speed, with its abundance being higher during the summer than other seasons. Analysis of temporal variations did not indicate any significant differences in the upper zone but did reveal variations among seasons at the lower zone. Except in 2014, the lower zone could be divided into periods dominated by diatoms (October-April) and dinoflagellates (June-August). These results suggest that the characteristics of the phytoplankton community were influenced by changes in the inflow of freshwater species and nutrients given the difference in the range affected by freshwater discharge.

• Korean journal of applied entomology
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• v.24 no.1 s.62
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• pp.34-38
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• 1985

Effects of some artificial diets containing pulverized silkworm pupae On the oviposition of a green lacewing, Chrysopa formosa, were studied. The pulverized silkworm pupae with honey seemed to be a good diet for the egg-laying activity of field-collected adults in the beginning of rearing, but their fecundity progressively decreased. Newly emerged adults. did. not lay eggs when fed the above diet, but they were able to lay eggs when the silkworm pupae were defatted and provided with honey. An adult female laid an average of 166.8, 110.2, 96.1, and 66.1 eggs after spending 5, 9, 9, and 11 days for the initiation of oviposition when supplied with various diets i.e. the cabbage aphid, defatted silkworm pupae with additive constituents, mixture of intact and defatted silkworm pupae with additive constituents, and defatted silkworm pupae with honey, respectively.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.21-33
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• 2012

Survey on the phytoplankton community structure and distribution in the upstream watershed of the East River was carried out during the period from May, 2008 to April, 2009. A total composition of phytoplankton included 159 taxa, consisting of 7 orders, 56 genera, 139 species, and 40 unidenfied species. Among those, the diatoms and green algae were more frequently found during the investigation than the other taxa. Cocconeis placentula, Cymbella minuta, Diatoma vulgare, Melosira varians, Navicula cryptocephala, Scenedesmus acuminatus v. acuminatus, were among the most common. The standing crops of the phytoplankton ranged from 86 cells $mL^{-1}$ to 1,467 cells $mL^{-1}$. The dominant species were Achnanthes minutissima, Asterionella formosa, Aulacoseira ambigua, Cocconeis placentula, Coelastrum microporum, Cyclotella sp., Cymbella affinis, C. minuta, C. tumida, Diatoma vulgare, Fragilaria capucina, F. construens, F. crotonensis, Gomphonema affine, G. clevei, Melosira varians, Merismopedia elegans, Navicula cryptocephala, N. pupula, Nitzschia tryblionella, Oscillatoria anna, O. limosa, O. tenuis v. tenuis, Pediastrum duplex v. reticulatum, Phormidium tenue, Scenedesmus acuminatus v. acuminatus, S. acutus v. acutus, S. ecornis v. ecornis, S. quadricauda v. quadricauda, Spirogyra sp., Stigeoclonium sp., Synedra acus, S. ulna, and Ulothrix sp. The most dominant species was Cymbella minuta. The diversity index, evenness index, and dominance index ranged from 1.58 to 3.10, 051 to 0.95, and 0.22 to 0.74, respectively. The phytoplankton community structure of upstream stations of the survey area was influenced by the effluent of the Doam Lake.

• ALGAE
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• v.22 no.4
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• pp.261-271
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• 2007

The variations of species compositions, standing crops and seasonal succession of phytoplanktons including Cyanophyceae, Chlorophyceae and Bacillariophyceae were investigated with physico-chemical elements of water to clarify the causes of water bloom according to the water depth in the Lake Unmun. The increased amounts of turbidity, T-N, T-P and SS originated from heavy rain and typhoon in the middle of June provoked to produce phytoplanktons. In July and August, the dominant species was Peridinium sp., while the subdominant species was Microcystis aeruginosa. In October, Aulacoseira distans was dominant and Asterionella formosa was subdominant. During the period of water shortage, the concentrated pollutants caused the decrease of precipitation, the long stagnation time of water body and the mixed pollutants by upwelling as decreasing water temperature could accelerate the water bloom. The preventives to decrease microalgal generation should be controled by the stagnation time of water body by increasing outflow to intercept water bloom such as ulacoseira sp. in October as well as summer.

• Textile Coloration and Finishing
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• v.22 no.2
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• pp.94-100
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• 2010

Colored compounds adsorption from the textile dyeing effluents on activated carbons produced from various indigenous vegetable sources by zinc chloride activation is studied. The most important parameters in chemical activation were found to be the chemical ratio of $ZnCl_2$ to feed (3:1), carbonization temperature (460-470 $^{\circ}C$) and time of activation (75 min). The absorbance at 511 nm (red effluent) and 615 nm (blue effluent) are used for estimation of color. It is established that at optimum temperature ($50^{\circ}C$), time of contact (30-40 min) and adsorbent loading (2 g/L), activated carbons developed from rain tree (Samanea saman) saw dust and blackberry (Randia formosa) tree saw dust showed great capability to remove color materials from the effluents. It is observed that adsorption of reactive dyes by all types of activated carbons is more than that of disperse dyes. It is explained that because of its acidic nature the activated carbon can adsorb better reactive dye particles containing large number of nitrogen sites and $-SO_3Na$ group in their structure. The use of activated carbons from the indigenous biomass would be economical, because saw dusts are readily available waste worldwide.

• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1720-1725
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• 2015

The performance of the AlGaN/GaN MSM-2DEG varactor with different dielectric films deposited by the E-beam deposition is investigated in detail. The capacitance swing and the capacitance ratio of the varactor without dielectric film as well as with, SiO₂, Gd₂O₃, and Si₃N₄ films, respectively, are determined by electrodes of varying areas. The maximum capacitance, the minimum capacitance and the capacitance ratios are proportional to the increasing of the electrode areas. The capacitance ratio determined by the maximum and the minimum capacitance is found to be 18.35 (with Si₃N₄ dielectric film) and 149.51 (without dielectric film), respectively. The transition voltages of the fabricated varactors are almost the same for a bias voltage of about ±5 V and leakage current can be lower three orders of magnitude while the varactors with dielectric films. The tunability of the capacitance ratio makes the AlGaN/GaN MSM-2DEG varactor with a dielectric film highly useful in multirange applications of a surge free preamplier.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5394-5409
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• 2019

The paper investigates a novel detector receiver with Kalman channel information estimator and iterative channel response equalization for MIMO (multi-input multi-output) OFDM (orthogonal frequency division multiplexing) communication systems in fast multipath fading environments. The performances of the existing linear equalizers (LE) are not good enough over most fast fading multipath channels. The existing adaptive equalizer with decision feedback structure (ADFE) can improve the performance of LE. But error-propagation effect seriously degrades the system performance of the ADFE, especially when operated in fast multipath fading environments. By considering the Kalman channel impulse response estimation for the fast fading multipath channels based on CE-BEM (complex exponential basis expansion) model, the paper proposes the iterative receiver with soft decision feedback equalization (SDFE) structure in the fast multipath fading environments. The proposed SDFE detector receiver combats the error-propagation effect for fast multipath fading channels and outperform the existing LE and ADFE. We demonstrate several simulations to confirm the ability of the proposed iterative receiver over the existing receivers.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.23-23
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• 2018

Taiwan, formerly known as Formosa, located on tropical and subtropical climate zones with abundant biological resources. According to the latest version of the Flora of Taiwan, there are 4339 species of vascular plants including 1054 endemic species. First, Taiwania (Taiwania cryptomerioides), named after its native island of Taiwan, have been isolated more than 500 secondary metabolites, including lignans, terpenoids, steroids, and flavonoids. Several of the metabolites are reported to have antibacterial, antifungal, antimite, antitermite and antitumor activities. In order to investigate plant secondary metabolic diversity toward industrial applications, we established deep transcriptome resources for non-model plants and fungi to produce terpenoid metabolites of economic importance. Second, many plants of Lauraceae have been utilized in folk medicine for their exciting bioactivities. The twigs and leaves from 27 tree species of Lauraceae grown in Taiwan were performed to evaluate potential bioactivity. The leaves of Cinnamomum osmophloeum are traditionally used in folk medicines, and many biological activities have been identified, such as antibacterial, antifungal, antitermite, antidiabetic, antihyperuricemia, antiinflammatory, and antioxidant activities. However, C. osmophloeum has nine chemotypes with various secondary metabolite profiles. In order to efficiently produce active compounds, we established the genetic markers to identify the chemotype plants. Finally, Cinnamomum kanehirae is the host of the medicinal mushroom Antrodia cinnamomea. Several in vivo and in vitro studies indicated that A. cinnamomea possesses a diverse range of biological activities. Because of the potential pharmacological application, we established the transformation system to enhance the triterpenoid contents production.

• Korean Journal of Veterinary Research
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• v.53 no.1
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• pp.65-68
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• 2013

Hepatitis E virus (HEV) can infect not only human but also several animals. This study has been conducted to evaluate the comprehensive anti-HEV seroprevalence in zoo animals in Korea. Anti-HEV antibodies were identified in 14 of 64 zoo animal species. HEV antibodies were detected for the first time in Eurasian Lynx, Setland Pony, Fallow Deer, Ezo Sika, Formosa Deer, East Wapitis, Barasingha, Corriedale, American Bison, Guanacos, Reticulated Giraffe, and Saanen. These results indicate that the several zoo animal species were exposed to HEV.

• Journal of Ecology and Environment
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• v.36 no.4
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• pp.245-254
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• 2013

This research was conducted over a time span of three years, from 2009 to 2011. Twenty-one surveys in total, seven times per year, were done between April and June of each year on major trees on trails around Donghaksa and Gapsa in Mt. Gyeryong National Park in order to identify foodplants of the Lepidoptera larvae and their characteristic appearances. During the survey of Lepidoptera larvae in trees along trails around Donghaksa and Gapsa, 377 individuals and 21 species in 8 families were identified. The 21 species were Alcis angulifera, Cosmia affinis, Libythea celtis, Adoxophyes orana, Amphipyra monolitha, Acrodontis fumosa, Xylena formosa, Ptycholoma lecheana circumclusana, Choristoneura adumbratana, Archips capsigeranus, Pandemis cinnamomeana, Rhopobota latipennis, Apochima juglansiaria, Cifuna locuples, Lymantria dispar, Eilema deplana, Rhodinia fugax, Acronicta rumicis, Amphipyra erebina, Favonius saphirinus, and Dravira ulupi. Twenty-one Lepidoptera insect species were identified in 21 species of trees, including Zelkova serrata. Among them, A. angulifera, C. affinis, and L. celtis were found to have the widest range of foodplants. Additionally, it was found that many species of Lepidoptera insects can utilize more species as foodplants according to the chemical substances in the plants and environments in addition to the foodplants noted in the literature. Also, it is thought that more species can be identified with a survey of various woody and herbaceous plants.