• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.262-266
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• 2003

The present study was carried out to investigate the relationships among intertillage and muddying by free-ranging ducks (Chinese native ducks) and pH, dissolved oxygen of irrigation water, and physicochemical properties of soil. Two paddy fields comprised of the muddying (muddy water without physical stimulation to a rice plant by the ducks) and the control plots (no ducks) were used for this study. As a muddying plot, 50 hills were randomly selected and each hill was fenced with a wire net in order to prevent from stimulating physically by the ducks. The variation in irrigation pH was smaller in the muddying plot than the control plot, and the pH was around 7.4. Dissolved oxygen was significantly higher (P＜0.01) in the muddying plot than the control plot during the first half period after the ducks were introduced. Then it decreased rapidly as the rice plants grew in all plots. The contents of the suspended soil and turbidity in irrigation water were not changed over the free-ranging period, but $\textrm{NH}_3\textrm{-N}$ and $\textrm{P}_2\textrm{O}_5$ were decreased by intertillage and muddying by the ducks. There were no differences in both the soil physics and chemistry between the muddying plot and the control plot during and after finishing of the free-ranging period. These results indicate that intertillage and muddying by the ducks resulted in a small variation in stagnant water pH, and reduced the dissolved oxygen and $\textrm{P}_2\textrm{O}_5$, although the physiochemical properties of soil were not changed.

• Journal of Wetlands Research
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• v.24 no.3
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• pp.196-203
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• 2022

This paper contributed to the understanding of the effect of the blade relative position on performance of micro gravitational vortex turbine in free water surface. In a constant vortex flow, the rotation, voltage and current of micro vortex water turbine were measured according to the position change of the blade installed at the relative vortex height (y/h_v) ranging from 0 to 0.778 below the free water surface. The flow rate ranged from 0.0063 to 0.00662 m³/s. The results of the experiments showed that relative positions of the blade affected the performance of vortex water turbine because the distributions of incoming flow velocity and turbulence intensity were changed. The highest amount of the energy generated by the vortex water turbine occurred in the relative vortex height ranging from 0.111 to 0.222. The output power at the relative vortex height of 0.111 was about 2.4 times larger than the relative vortex height of 0.588 below the free water surface.

• Bulletin of the Korean Chemical Society
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• v.26 no.3
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• pp.379-383
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• 2005

This research aims to develop DNA chip array without an indicator. We fabricated microelectrode array by photolithography technology. Several DNA probes were immobilized on an electrode. Then, indicator-free target DNA was hybridized by an electrical force and measured electrochemically. Cyclic-voltammograms (CVs) showed a difference between DNA probe and mismatched DNA in an anodic peak. Immobilization of probe DNA and hybridization of target DNA could be confirmed by fluorescent. This indicator-free DNA chip microarray resulted in the sequence-specific detection of the target DNA quantitatively ranging from $10^{-18}\;M\;to\;10^{-5}$ M in the buffer solution. This indicator-free DNA chip resulted in a sequence-specific detection of the target DNA.

• The Journal of Information Systems
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• v.27 no.3
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• pp.63-80
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• 2018

Purpose The purpose of this study is to build a machine learning-based customer classification model to promote customer expansion effect of the free sample promotion. Specifically, the proposed model classifies potential target customers who are expected to purchase the products included in the free sample promotion after receiving the free samples. Design/methodology/approach This study proposes to build a customer classification model for determining customers suitable for providing free samples by using various machine learning techniques such as logistic regression, multiple discriminant analysis, case-based reasoning, decision tree, artificial neural network, and support vector machine. To validate the usefulness of the proposed model, we apply it to a real-world free sample-based target marketing case of a Korean major cosmetic retail company. Findings Experimental results show that a machine learning-based customer classification model presents satisfactory accuracy ranging from 70% to 75%. In particular, support vector machine is found to be the most effective machine learning technique for free sample-based target marketing model. Our study sheds a light on customer relationship management strategies using free sample promotions.

• IEMEK Journal of Embedded Systems and Applications
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• v.7 no.2
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• pp.71-78
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• 2012

Based on the Zigbee-based wireless sensor network, I suggest the way to reduce errors between the short distance, improving the accuracy of the presumed distance by revising the deviation of RSSI(Received Signal Strength Indication) values is to estimate the distance using only the RF signal power without the additional hardware. In general, the graph measured by RSSI values shows the proximity values which are ideally reduced in proportion to the distance under the free outdoor space in which LOS(Line-Of-Sight) is guaranteed. However, if the result of the received RSSI values are each substituted to the formula, it can produce a larger margin of error and less accurate measurement since it is based upon the premise that this free space is not affected by reflected waves or obstacles caused by the ground and electronic jamming engendered by the environment. Therefore, the purpose of this study is to reduce the margin of errors between the distances and to measure the proximity values with the ideal type of graph by suggesting the way to revise the received RSSI values in the light of these reflected waves or obstacles and the electronic jamming. In conclusion, this study proves that errors are reduced by comparing the proposed deviation correction method to the revised RSSI value.

• Parasites, Hosts and Diseases
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• v.49 no.4
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• pp.437-440
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• 2011

Babesia spp. were detected from 4 asymptomatic pukus captured on a game ranch in central Zambia in October 2008. Blood smears were examined in 4 species of aymptomatic free-ranging antelopes, namely the puku (Kobus vordanii), reedbuck (Redunca arundinum), bushbuck (Tragelaphus sylvaticus), and kudu (Tragelaphus strepsiceros), and showed the presence of Babesia parasites only in the puku. In the puku, the prevalence of babesiosis was estimated at 33.3% (n=12), while the overall prevalence in all examined animals was 8.5% (n=47). The parasites showed morphological characteristics of paired ring-like stages with the length varying between $1.61{\mu}m$ and $3.02{\mu}m$ ($mean=2.12{\mu}m$, n=27; $SD=0.76{\mu}m$). Both the infected and non-infected pukus showed good body condition scores (BCS), while the dominant tick species detected from all animals were Rhipicephalus appendiculatus, Rhipicephalus spp., and Boophilus spp. To our knowledge this is the first report of Babesia spp. infection in pukus in Zambia. These findings suggest that wildlife could play an important role in the epidemiology of babesiosis in Zambia.

• The Journal of Korean Medicine
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• v.38 no.2
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• pp.1-6
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• 2017

Objectives: Natural environment therapy is considered as an option for atopic dermatitis. This study was aimed to examine the beneficial effects of natural environment therapy among patients with atopic dermatitis who have moved in an atopy-free village. Methods: The questionnaire-based survey was conducted from parents of 20 children with atopic dermatitis (12 male and 8 female, median age 8 years, ranging from 6 to 13 years). The questionnaire consisted of 10 questions for the changes of two typical symptoms of pruritus and sleeping difficulty after moving into an atopy-free village. Results: 75.0% and 88.9% of patients have a family history (at least one parent and one of siblings respectively) of allergic disorders. The median staying period of patients was 27.6 months (ranging from 2 to 55 months). The score indicating pruritus was significantly improved from $6.2{\pm}2.8$ into $4.8{\pm}1.8$ (p<0.05), and sleeping difficulty was also improved from $5.7{\pm}2.9$ into $4.3{\pm}2.1$ (p<0.05) too. Conclusions: This study suggests that the natural environmental therapies could be a choice for patients with atopic dermatitis, which should be studied further for their scientific evidence and mechanisms.

• Wind and Structures
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• v.34 no.4
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• pp.385-394
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• 2022

Global Warming has been driven majorly by the consumption of fossil fuels. Harnessing energy from wind is viable solution towards reducing carbon footprint created due to burning such fuels, However, wind turbines have their problems of flow separation and aerodynamic stall to tackle with. In an attempt to delay the stall angle and improve the aerodynamic characteristics of the NACA 0015 symmetrical aerofoil, lateral cylindrical ridges were attached to its suction surface, at chord positions ranging from 0.1c to 0.5c. The characteristics of the original and ridged aerofoils were obtained using simultaneous pressure readings taken in a wind tunnel, at a free stream Reynolds number of R_e = 2.81 × 10⁵ for a wide range of free stream angles of attack ranging from -45° to 45°. Depending on the ridge size, a delay in stall angle varying from 5° to 20° was achieved together with the maximum increase in lift in the post-stall phases. Additionally, efforts were made to identify the optimum position for each ridge.

• Fisheries and Aquatic Sciences
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• v.26 no.11
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• pp.669-677
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• 2023

The spotted seal (Phoca largha) in the Yellow Sea has declined due to poaching and habitat destruction. To aid conservation efforts, Argos satellite tracking were used to monitor the movements of a free ranging spotted seal around Baengnyeongdo Island. The satellite-transmitting tag successfully attached to the seal provided 1,556 location data collected during 107 days. The seal mostly moved between two haul-out sites, Yeonbong Rock and Mulbeom Rock. From October 6th to December 12th, the seal stayed within a 7 km radius of Yeonbong Rock. However, as the signal was lost, it was not possible to identify when the seal started to migrate from Baengnyeongdo Island to winter breeding area. This study provide understanding into the habitat preferences and movement patterns of spotted seals around Baengnyeongdo Island, contributing to the conservation and management of this species. Further research with more individuals and different age groups is essential to understand their habitat preference and develop effective conservation measures for the spotted seal population in the Yellow Sea.

• Culinary science and hospitality research
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• v.23 no.7
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• pp.42-49
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• 2017

This study was conducted to determine the nutritional value of domestic cherry tomato varieties (Summerking, Qutiquti, and Minichal). The levels of amino acids, amino acid derivatives, and ${\gamma}-aminobutyric-acid$ (GABA) were analyzed using ion chromatography. In domestic cherry tomatoes, eighteen free amino acids were found including L-glutamic acid (L-Glu), L-glutamine (L-Gln), and L-aspartic acid (L-Asp). L-Glu was the most abundant amino acid, ranging from 1,533.17 mg/100 g to 1,920.65 mg/100 g (dry weight). The next abundant amino acids were L-Gln, ranging from 784.68 mg/100 g to 1,164.36 mg/100 g and L-Asp, ranging from 320.73 mg/100 g to 387.22 mg/100 g. Domestic cherry tomatoes contained eight essential amino acids except tryptophan and the total essential amino acid content was 297.30~432.43 mg/100 g (dry weight), which was 8.92~10.61% of total free amino acid. Several amino acid derivatives were found: L-carnitine (L-Car), hydroxylysine (Hyl), o-phosphoethanolamine (o-Pea), phosphoserine (p-Ser), ${\beta}-alanine$ (${\beta}-Ala$), N-methyl-histidine (Me-His), ethanolamine ($EtNH_2$), and L-citrulline (L-Cit). L-Car, transporting long-chain fatty acid into mitocondrial matrix, was the most abundant amino acid derivative in all domestic cherry tomatoes. A high level of GABA (313.18~638.57 mg/100 g), known as a neurotransmitter, was also found in all three domestic cherry tomatoes. These results revealed that domestic cherry tomatoes have a good balance of nutrient and bioactive compounds. Therefore, cherry tomatoes can be used as a functional food material.