• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.295-301
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• 2003

This study was carried out to investigate perception about body image, dietary attitude, nutrient intake and dietary self-efficacy of high school students in Pusan. A questionaire survey was distributed among 491 high school students. The survey was conducted from April 8 to April 22 in 2002. The results are summarized as follows. Forty percents of the underweight group, 53.9% of the normal weight group, 61.8% of the overweight group and 48.2% of obesity group have correct perception about their body image. Most of the students were concerned with their body image and weight control. Obesity of parents was significantly correlated with obesity of the subjects (p<0.01). The higher obesity rate, the lower dietary self-efficacy. The higher dietary self-efficacy, the higher dietary attitude. There was a significant positive correlation between the education level of their parents and dietary attitude of the subjects (p<0.01) and a significant negative correlation between obesity rate of their mothers and dietary attitude of the subjects (p<0.01). Dietary attitude scores showed no significant difference among the groups. Intakes of most nutrients, except protein, niacin and vitamin C, were lower than those of the recommended dietary allowances for Koreans. Therefore, proper nutrition education is required to improve their nutritional status and dietary self-efficacy.

• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.365-370
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• 2012

In this study, Economic analysis of supercritical coal-fired power plant with $CO_2$ capture process was performed. For this purpose, chemical absorption method using amine solvent, which is commercially available and most suitable for existing thermal power plant, was studied. For the evaluation of the economic analysis of coal-fired power plant with post-combustion $CO_2$ capture process in Korea, energy penalty after $CO_2$ capture was calculated using the power equivalent factor suggested by Bolland et al. And the overnight cost of power plant (or cost of plant construction) and the operation cost reported by the IEA (International Energy Agency) were used. Based on chemical absorption method using a amine solvent and 3.31 GJ/$tonCO_2$ as a regeneration energy in the stripper, the net power efficiency was reduced from 41.0% (without $CO_2$ capture) to 31.6% (with $CO_2$ capture) and the levelized cost of electricity was increased from 45.5 USD/MWh (Reference case, without $CO_2$ capture) to 73.9 USD/MWh (With $CO_2$ capture) and the cost of $CO_2$ avoided was estimated as 41.3 USD/$tonCO_2$.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.400-406
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• 2018

In this experiment the effect of supplemental lighting on the growth and yield of cucumber (Cucumis sativus L. 'Fresh') plants during low radiation period of winter season were investigated in glasshouses using common high-pressure sodium (HPS) lamps and newly developed plasma lighting system (PLS) lamps. Plants grown without supplemental lighting were considered as a control. Supplemental lighting was provided from November 20th, 2015 to March 15th, 2016 to ensure 14-hour photoperiod (natural+supplemental light), also lamps were operated automatically when the outside sun radiation levels were less than $100W{\cdot}m^{-2}$. Spectral analysis showed that HPS lamp had a discrete spectrum, lacked of the radiation in the 400-550 nm wave band (blue-green light), but had a high output in the orange-red region (550-650 nm). A higher red light output resulted in an increased red to far-red (R/FR) ratio in HPS lamp. PLS had a continuous spectrum and had a peak radiation in green region (490-550 nm). HPS has 12.6% lower output in photosynthetically active radiation (PAR) but 12.6% higher output in near infra-red (NIR) spectral regions compared to PLS. Both HPS and PLS lamps emitted very low levels of ultra-violet radiation (300-400 nm). Supplemental lighting both from HPS and PLS lamps increased plant height, leaf number, internode number and dry weight of cucumber plants compared to control. Photosynthetic activity of cucumber plants grown under two supplemental lighting systems was comparable. Number of fruits per cucumber plant (fruit weight per plant) in control, PLS, and HPS plots were 21.2 (2.9 kg), 38.7 (5.5 kg), and 40.4 (5.6 kg), respectively, thereby increasing yield by 1.8-1.9 times in comparison with control. An analysis of the economic feasibility of supplemental lighting in cucumber cultivation showed that considering lamp installation and electricity costs the income from supplemental lighting increased by 37% and 62% for PLS and HPS lamps, respectively.

• Journal of Life Science
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• v.22 no.12
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• pp.1672-1679
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• 2012

The effect of high stocking density (HSD) on the expression of stress and lipid metabolism associated genes in the liver of broiler chickens was examined by chicken genome array analysis. The chickens in a control group were randomly assigned to a $495cm^2/bird$ stocking density, whereas the chickens in a HSD group were arranged in a $245cm^2/bird$ stocking density with feeding ad libitum for 35 days. The chickens assigned to the HSD group had a significantly lower body weight, weight gain, and feed intake compared with those of the control group (p<0.05). The mortality of chickens was higher in the HSD group than in the control group. The microarray analysis indicated up-regulation of stress associated genes such as HMGCR, $HSP90{\alpha}$, HSPA5 (GRP78/Bip), DNAJC3 and ATF4, and down-regulation of interferon-${\gamma}$ and PDCD4 genes. The endoplasmic reticulum stress associated genes, HSPA5 (GRP78/Bip), DNAJC3 and ATF4, were highly expressed in the HSD group. The genes, ACSL5, TMEM195 and ELOVL6, involved in fatty acid synthesis, were elevated in the HSD group. The genes, ACAA1, ACOX1, EHHADH, LOC423347 and CPT1A, related to fatty acid oxidation, were also activated in the HSD group. These results suggest that a HSD rearing system stimulates the genes associated with fatty acid synthesis as well as fatty acid oxidation in the liver of broiler chickens.

• Korean Chemical Engineering Research
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• v.51 no.3
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• pp.313-318
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• 2013

In order to investigate the effect of $V_2O_5$ loading of $V_2O_5-WO_3/TiO_2$ catalyst on the NO reduction and the formation of $N_2O$, the experimental study was carried out in a differential reactor using the powder catalyst. The NO reduction and the ammonia oxidation were, respectively, investigated over the catalysts compose of $V_2O_5$ content (1~8 wt%) based on the fixed composition of $WO_3$ (9 wt%) on $TiO_2$ powder. $V_2O_5-WO_3/TiO_2$ catalysts had the NO reduction activity even under the temperature of $200^{\circ}C$. However, the lowest temperature for NO reduction activity more than 99.9% to treat NO concentration of 700 ppm appeared at 340 with very limited temperature window in the case of 1 wt% $V_2O_5$ catalyst. And the temperature shifted to lower one as well as the temperature window was widen as the $V_2O_5$ content of the catalyst increased, and finally reached at the activation temperature ranged $220{\sim}340^{\circ}C$ in the case of 6 wt% $V_2O_5$ catalyst. The catalyst of 8 wt% $V_2O_5$ content presented lower activity than that of 8 wt% $V_2O_5$ content over the full temperature range. NO reduction activity decreased as the $V_2O_5$ content of the catalyst increased above $340^{\circ}C$. The active site for NO reduction over $V_2O_5-WO_3/TiO_2$ catalysts was mainly related with $V_2O_5$ particles sustained as the bare surface with relevant size which should be not so large to stimulate $N_2O$ formation at high temperature over $320^{\circ}C$ according to the ammonia oxidation. Currently, $V_2O_5-WO_3/TiO_2$ catalysts were operated in the temperature ranged $350{\sim}450^{\circ}C$ to treat NOx in the effluent gas of industrial plants. However, in order to save the energy and to reduce the secondary pollutant $N_2O$ in the high temperature process, the using of $V_2O_5-WO_3/TiO_2$ catalyst of content $V_2O_5$ was recommended as the low temperature catalyst which was suitable for low temperature operation ranged $250{\sim}320^{\circ}C$.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.4
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• pp.333-340
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• 2010

Wastewater treatment using algal communities and biodiesel production from wastewater-cultivated algal biomass is a promising green growth technology. In literature, there are many studies providing information on algal species producing high content of lipid. However, very little is known about adaptability and wastewater treatability of such high-lipid algal species. In this study, we attempted to characterize algal biomass production and wastewater treatability of high-lipid algal species under municipal wastewater condition. For this, four known high-lipid algal strains including Chlorella vulgaris AG 10032, Ankistrodesmus gracilis SAG 278-2, Scenedesmus quadricauda, and Botryococcus braunii UTEX 572 were individually inoculated into municipal wastewater where its indigenuous algal populations were removed prior to the inoculation, and the algae-inoculated wastewater was incubated in the presence of light source (80${\mu}E$) for 9 days in laboratory batch reactors. During the incubations, algal biomass production (dry weight) and the removals of dissolved organics (COD), nitrogen and phosphorous were measured in laboratory batch reactors. According to algal growth results, C. vulgaris, A. gracilis and S. quadricauda exhibited faster growth than indigenuous wastewater algal populations while B. braunii did not. The wastewater-growing strains exhibited efficient removals of total-N, ${NH_4}^+$-N, Total-P and ${PO_4}^{3-}$-P which satisfy the Korea water quality standards for effluent from municipal wastewater treatment plants. A. gracilis and S. quadricauda exhibited efficient and stable treatability of COD but C. vulgaris showed unstable treatability. Taken together with the results, A. gracilis and S. quadricauda were found to be suitable species for biomass production and wastewater treatment under municipal wastewater condition.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.58-67
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• 2014

The outdoor mass cultivation is not possible for microalgae in Korea all year round, due to cold winter season. It is not easy to maintain proper level of productivity of microalgae even in winter. To prevent a drastic decrease of temperature in a greenhouse, two layers were covered additionally, inside the original plastic layer of the greenhouse. The middle layer was made up of plastic and the inner layer, of non-woven fabric. Acrylic transparent bioreactors were constructed to get more sunlight, not only from the upper side but also from the lateral and bottom directions. In winter at freezing temperatures, six different culture conditions were compared in the triply covered, insulated greenhouse. Wastewater after anaerobic digestion was used for the cultivation of microalgae to minimize the production cost. Water temperature in the bioreactors remained above $10^{\circ}C$ on average, even without any external heating system, proving that the triple-layered greenhouse is effective in keeping heat. Algal biomass reached to 0.37g $L^{-1}$ with the highest temperature, in the experimental group of light-reflection board at the bottom, with nitrogen and phosphorus removal rate of 92% and 99%, respectively. When fatty acid composition was analyzed using gas-chromatography, linoleate (C18 : 3n3) occupied the highest proportion up to 61%, in the all experiment groups. Chemical oxygen demand (COD), however, did not decrease during the cultivation, but rather increased. Although the algal biomass productivity was not comparable to warm seasons, it was possible to maintain water temperature for algae cultivation even in the coldest season, at the minimum cost.

• Journal of KIISE:Information Networking
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• v.30 no.3
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• pp.329-342
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• 2003

Most of the existing multicast routing protocols for ad-hoc networks do not take into account the efficiency of the protocol for the cases when there are large number of sources in the multicast group, resulting in either large overhead or poor data delivery ratio when the number of sources is large. In this paper, we propose a multicast routing protocol for ad-hoc networks, which particularly considers the scalability of the protocol in terms of the number of sources in the multicast groups. The proposed protocol designates a set of sources as the core sources. Each core source is a root of each tree that reaches all the destinations of the multicast group. The union of these trees constitutes the data delivery mesh, and each of the non-core sources finds the nearest core source in order to delegate its data delivery. For the efficient operation of the proposed protocol, it is important to have an appropriate number of core sources. Having too many of the core sources incurs excessive control and data packet overhead, whereas having too little of them results in a vulnerable and overloaded data delivery mesh. The data delivery mesh is optimally reconfigured through the periodic control message flooding from the core sources, whereas the connectivity of the mesh is maintained by a persistent local mesh recovery mechanism. The simulation results show that the proposed protocol achieves an efficient multicast communication with high data delivery ratio and low communication overhead compared with the other existing multicast routing protocols when there are multiple sources in the multicast group.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.283-293
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• 2002

Purpose : A PC based brachytherapy planning system was developed to display dose distributions on simulation images by 2D isodose curve including the dose profiles, dose-volume histogram and 30 dose distributions. Materials and Methods : Brachytherapy dose planning software was developed especially for the Ir-192 source, which had been developed by KAERI as a substitute for the Co-60 source. The dose computation was achieved by searching for a pre-computed dose matrix which was tabulated as a function of radial and axial distance from a source. In the computation process, the effects of the tissue scattering correction factor and anisotropic dose distributions were included. The computed dose distributions were displayed in 2D film image including the profile dose, 3D isodose curves with wire frame forms and dosevolume histogram. Results : The brachytherapy dose plan was initiated by obtaining source positions on the principal plane of the source axis. The dose distributions in tissue were computed on a $200\times200\;(mm^2)$ plane on which the source axis was located at the center of the plane. The point doses along the longitudinal axis of the source were $4.5\~9.0\%$ smaller than those on the radial axis of the plane, due to the anisotropy created by the cylindrical shape of the source. When compared to manual calculation, the point doses showed $1\~5\%$ discrepancies from the benchmarking plan. The 2D dose distributions of different planes were matched to the same administered isodose level in order to analyze the shape of the optimized dose level. The accumulated dose-volume histogram, displayed as a function of the percentage volume of administered minimum dose level, was used to guide the volume analysis. Conclusion : This study evaluated the developed computerized dose planning system of brachytherapy. The dose distribution was displayed on the coronal, sagittal and axial planes with the dose histogram. The accumulated DVH and 3D dose distributions provided by the developed system may be useful tools for dose analysis in comparison with orthogonal dose planning.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.1
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• pp.39-48
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• 2012

This study was conducted to investigate effects of different levels of seleniferous whole crop barley (WCB) supplementation on performance, and blood characteristics as physiological responses in growing pigs. A total of 20 cross-bred pigs ((Landrace ${\times}$ Yorkshire) ${\times}$ Duroc) were divided into 4 treatments of 5 pigs each and experimental period lasted for 6 weeks. They were fed diets containing 0.1 (non-seleniferous WCB as controls), 0.2, 0.4, and 0.6 mg/kg levels of selenium (Se) by supplementing seleniferous WCB, and non-seleniferous or seleniferous WCB was formulated to 5% level in total ration. The diets were isonitrogenous (18% crude protein) and isocaloric (3,500 kcal/kg digestible energy) across treatments. Increasing levels of seleniferous WCB supplements did not affect feed intake and BW gain, and blood total protein concentration was (p<0.05) significantly higher for 0.2 mg/kg Se treatments than for controls. On d 14, blood albumin concentration was higher (p<0.05) for seleniferous WCB supplemented groups than for control group. Contrarily, blood glucose concentration was tended to be higher for controls than for seleniferous WCB groups. Blood total lipid concentration was significantly (p<0.05) lowered with increasing levels of seleniferous WCB. Serum glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase did not have any difference among treatments. It was tended that blood total cholesterol and triglyceride were lowered with increasing levels of seleniferous WCB. Blood Se concentration was significantly (p<0.05) increased with increasing levels of seleniferous WCB. The results indicate that Se present in seleniferous WCB had favorable effects on blood characteristics and blood Se increased by supplementing seleniferous WCB implies not only a good intestinal absorption of Se present in WCB but also the possibility of Se transfer into tissues.