• Journal of Venture Innovation
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• v.2 no.2
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• pp.79-94
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• 2019

The purpose of this study is to explore the factors affecting rural experience by applying the unified push-pull-mooring model. The theoretical model is an unified PPM model that introduces new variables based on PPM. The pull factor of the newly introduced variables were reconstructed based on the Schmitt's Experience model and ServQual model. The hypothesis is set as follows. The push factor will have a negative effect on experience satisfaction and the pull factor(experience attributes, service quality)will have a positive effect on experience satisfaction. Also, mooring factors will have a negative effect on experience satisfaction. The research model of this study was tested by structural equation model based on 314 effective questionnaire data. Service quality had a positive effect on experience satisfaction. Mooring factors have a negative effect on experience satisfaction. Push factor and experience attributes factor were analyzed to have a no significance effect on experience satisfaction. These results theoretically test that the mooring factors also have an important effect on the experience satisfaction in the rural experience. Based on the Schmitt's Experience model and ServQual model introduced as a pull factor, the proposed unified PPM model proved to be a useful analysis framework. In practice, it was able to provide implications on what factors should be strategically and marketingly focused to activate the 6th industry experience.

• Korean journal of applied entomology
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• v.62 no.3
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• pp.155-160
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• 2023

In this study, we investigated the functional response of aphid parasitoid, Aphidius colemani Viereck (Hymenoptera: Braconidae), on the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae). Three carbon dioxide concentrations (400, 600, and 1000ppm) and seven host densities (2, 4, 8, 16, 32, 64, and 128) were used during a 24-h period. A type III functional response for A. colemani was fit separately for each CO₂ concentration. The estimated handling time (Th) under elevated CO₂ (600 ppm and 1000 ppm, 0.015 and 0.014 day) was shorter than that under ambient CO₂ (400 ppm, 0.017 day). The proportion of aphids that were parasitized showed the similar characteristic curve under three CO₂ concentrations. The highest parasitized rates for A. colemani were 0.57, 0.61, and 0.70 at 16, 32, and 32 aphid density under 400, 600, and 1000ppm, respectively. Although handling time of A. colemani was influenced by elevated CO₂ concentrations, the attach rate was not changed much.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2418-2425
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• 2021

Monazite is a phosphate mineral that contains thorium (Th) and rare earth elements. The Th concentration in monazite can be as high as 500 ppm, and it has the potential to be used as fuel in the nuclear power system. Therefore, this study aimed to conduct the techno-economic analysis (TEA) of Th extraction in the form of thorium oxide (ThO₂) from monazite. Th can be extracted from monazite through an alkaline fusion method. The TEA of ThO₂ production studied parameters, including raw materials, equipment costs, total plant direct and indirect costs, and direct fixed capital cost. These parameters were calculated for the production of 0.5, 1, and 10 ton ThO₂ per batch. The TEA study revealed that the highest production cost was ascribed to installed equipment. Furthermore, the highest return on investment (ROI) of 21.92% was achieved for extraction of 1 ton/batch of ThO₂, with a payback time of 4.56 years. With further increase in ThO₂ production to 10 ton/batch, the ROI was decreased to 5.37%. This is mainly due to a significant increase in the total capital investment with increasing ThO₂ production scale. The minimum unit production cost was achieved for 1 ton ThO₂/batch equal to 335.79 $/Kg ThO₂.

• Journal of Communications and Networks
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• v.10 no.1
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• pp.63-70
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• 2008

Narrow-band interference (NBI) from the coexisting narrow-band services affects the performance of ultra wideband (UWB) systems considerably due to the high power of these narrow-band signals with respect to the UWB signals. Specifically, IEEE 802.11a systems which operate around 5 GHz and overlap the band of UWB signals may interfere with UWB systems significantly. In this paper, we suggest a novel NBI suppression technique based on singular value decomposition (SVD) algorithm in time hopping UWB (TH-UWB) systems. SVD is used to approximate the interference which then is subtracted from the received signals. The algorithm precision and closed-form bit error rate (BER) expression are derived in the wireless multipath channel. Comparing with the conventional suppression methods such as a notch filter and a RAKE receiver, the proposed method is simple and robust and especially suitable for UWB systems.

• Korean Journal of Environmental Biology
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• v.28 no.2
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• pp.64-68
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• 2010

The mosquito, Aedes albopictus is important vector of humen phatogen such as dengue fever. And Aedes albopictus has widly distribution in oriental regions. This study was conducted to investigate the biological effects of cooper on the development of the Asian tiger mosquitoes, Aedes albopictus (Skuse). Aedes albopictus was affected with pupation ratios, mortalities, and wing lengths of the 3th and 4th instars by exposure to different concentration $CuCl_2$ (0.0, 2.5, 25.0 and 50.0 ppm) for 24 h and 48 h depending on dose and exposure period. The lowest $LC_{50}$ (median lethal concentration) value of $CuCl_2$ was 18.1 ppm at the 3rd instars for 48 h exposure. The pupation ratio of the larvae exposed at 50.0 ppm for 48 h was 14% which was much lower than those exposed to other treatment groups Changes of adult wing length showed significant decreased by Cu treatment. In conclusion, the most prominent effects of high concentration and longer exposure period were to reduce in the survival and pupation rates of larvae and wing length of Ae. albopictus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.2
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• pp.69-78
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• 1974

A study on the contents of dissolved oxygen and phytoplankton in the pond water has been carried out to determine the water quality and to investigate the cause of red water in fish ponds at Pusan Fisheries College in 1972-1973. The results obtained are as follows : 1. Measured oxygen content during the period from 6th to 7th of August 1972 was: 23.95ppm ($328\%$ in saturation rate) in daytime and 0.39 ppm($5\%$) in the early morning in the water which contains heavy bloom of phytoplankton, on the other hand, in clear water the range of oxygen content was 8.72 to 6.58ppm. 2. The occurrences of red water in 1972-1973 were always caused by the sudden death of Synechocystis aquatilis (Cyanophyta) when the water temperature was very high ($30-33.5^{\circ}C$) and then high mortality of fish under rearing followed. 3. The phytoplankon observed during this study period was 133 species belonging to 55 genera in 23 families, and those of Chlorophyta was dominant in number of species, and Cyanophyta in quantity. 4. Zooplankton observed was 12 species belonging to 11 genera in 11 families, and they were very small both in number of species and in quantity compared to those of phytoplankton.

• Korean Journal of Organic Agriculture
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• v.12 no.1
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• pp.81-92
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• 2004

The effect of feeding extracts from rhus trees on performance of broiler were performed to investigate development of natural antibiotic in process of broilers production. A total of 320 broiler chicks at 7 day of age were fed the commercial diet and water, water containing 0 ppm (control), 300 ppm (T1), 600 ppm (T2) and 1000 ppm (T3) of extracts from rims trees for 7 weeks. The body weight gain and feed conversion ratio were improvement by feeding extracts from rims trees at 7 to 21 days of age (P<0.05), but amount of feed intake and mortality were not different among the four group. When 21 to 35 days of age, body weight gain, amount of feed intake, feed conversion ratio and mortality were almost same results when 7 to 21days of age, but it was not significantly different. When 35 to 49 days of age, body weight gain in T1 and T3 group was significantly improvement than control group (P<0.05), also feed conversion ratio was improve by feeding extracts from rhus trees. There was a decrease in the microflora population of both E coli. and salmonella in the cecum contents and feaces in broilers by feeding extracts from rhus trees. Emission of ammonia and VFA gas from excreta were significantly decreased at 5 to 10 days of storaged period (P<0.05). The digestibility of dry matter, crude fat, and crude ash of feed were tend to increased in broiler feeding extracts from rims trees. Digestibility of crude protein of feed in broiler three treatmental groups was significantly improved (P<0.05) as compared with those in control group. These results indicated that the feeding extracts from rhus trees of 300 to 1000 ppm of broiler production were improvement in th6 body weight gain, feed conversion ratio, and mortality due to increasing nutrients digestibility from feed, decreasing of microflora population of both E coll. and salmonella in the cecum contents and feaces, decreasing emission of ammonia and VFA gas from excreta.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.3
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• pp.375-383
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• 2005

An experiment was conducted to study the protective role of polyherbal feed supplement (Growell) during induced mycotoxicosis in broilers. A total of 240 Vencobb broilers were divided at day old stage into eight equal groups. Group A served as control and was given plain feed, group B, D, F and H were given Growell at 0.35 g/kg of feed. Group C, D, G and H were given dietary aflatoxin $B_1$ at 0.2 ppm and groups E, F, G and H were given ochratoxin A at 0.2 ppm in feed to study effect of Growell on individual aflatoxicosis, ochratoxicosis and combined mycotoxicosis of broilers. The chicks were given their respective feeds from 1st day to 6th week of age and were vaccinated at 7th and 28th day of age with Lasota strain of Newcastle disease virus. There was no statistically significant effect of mycotoxins individually or in combination on body weight of broilers. However, body weights were highest in group B and lowest in co-mycotoxicated group G. Feed conversion ratio was best in group B followed by A, D, F, E, H and G. Significant improvement in haemoglobin values was observed in broilers due to feeding of Growell in ochratoxin and co-mycotoxicated groups. There was no significant effect of mycotoxin treatment on PCV, TEC and TLC of broilers. Due to single and combined mycotoxicosis, there was reduction in serum total protein, albumin, cholesterol and triglyceride and rise in alkaline phosphatase, creatinine and uric acid levels. Supplementation of diets with Growell reduced the alterations induced due to mycotoxins. There was a significant rise in per cent organ weight of liver and reduction of that of spleen, bursa of Fabricius and thymus of broilers fed mycotoxins. Protection from alteration in per cent organ weight of these organ by supplementation of Growell was recorded. The observed impaired immune response and histopathological changes in liver, kidney, spleen, bursa of Fabricius and thymus of broilers given mycotoxins were protected by supplementation of Growell.

• Journal of the Korean Ceramic Society
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• v.39 no.6
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• pp.535-539
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• 2002

In this study photoadsorption propreties of Ag ion in AgNO$_3$ solution by TiO$_2$nanopowder synthesized by homogeneous precipitation process at low temperature were investigated. It was found that the photocatalytic redliction in AgNO$_3$solution was occurred by TiO$_2$nanopowder even under th sun light irradiation, although the reduction of Ag ions was slow with th small adsorption of 9.32 ppm. Notably the Ag adsorption was promoted in th dark condition probably owing to the chestnut bur shape of TiO$_2$ nanopowder itself. In the application of UV the Ag ions were completely adsorbed within 120 min, showing more significant photocatalytic reaction. The measured adsorption reaction rate and adsorption equilibrium rate constants were 0.0004 g/min and 1494.20(120 $m^2$/g), respectively.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.62-69
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• 2013

The black cutworm, Agrotis ipsilon (Hufnagel), damages various cultivated crops and it can also be a serious pest of turfgrass, especially on golf courses. Essential oils have potential as alternative control agents for insect pests. Sixteen essential oils (anise, camphor, cinnamon, citronella, clove, fennel, geranium, lavender, lemongrass, linseed, neem, peppermint, pine, thyme, turpentine and tea saponin) and paraffin oil were assessed in the laboratory, the green house and field trials for their efficacy against black cutworms in turf. Treatment of potted cores of perennial ryegrass turf with anise, cinnamon, neem, paraffin or turpentine reduced black cutworm damage in a greenhouse trial, and in a similar trial, applying neem oil at 4000, 2000 and 1000 ppm resulted in 100, 100 and 64% mortality, respectively, of black cutworms. Weight of survivors at the 1000 ppm rate was 5- fold less than weight of comparably-aged controls. Neem oil (2000 ppm) reduced growth of black cutworms feeding on treated clippings. A high rate of neem oil followed by irrigation (0.1 L of 20000 ppm neem oil with 0.9 L watering/$m^2$) was more effective than a lower concentration (1 L of 2000 ppm neem oil/$m^2$) against $2^{nd}$ and $3^{rd}$ instars in potted turf cores and field plots, respectively. However, not even the aforementioned higher rate effectively controlled $4^{th}$ instars in the field.