• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.7 no.4
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• pp.188-194
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• 2014

In this paper, an antenna which has quad band in LTE (0.746 ~ 0.798 GHz), GSM(0.824 ~ 0.960 GHz), DCS(1.71 ~ 1.88 GHz), WCDMA(1.91 ~ 2.17 GHz) is proposed. An antenna size is $122mm{\times}50mm{\times}0.8mm$ on FR4(${\epsilon}_r=4.4$) ground substrate. In the proposed antenna, branch line is applied to the conventional PIFA architecture to achieve multi-bandwidth. Coupling power supply is applied for a wide bandwidth. Result of the measurement is as follows. When the low frequency, the antenna presents gain of 0.93 ~ 1.92dBi, and radiation efficiency of 49.60 ~ 76.35 %, and When the high frequency, gain is 2.19 ~ 4.66dBi, and radiation efficiency is 60.40 ~ 80.01 %, and with a VSWR < 2 (${\leq}-10dB$)measurement results for standard satisfies all band. Judging from the result, proposed multiband antenna is expected to be applied. B4G mobile terminals since the antenna shows an outstanding performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.1013-1019
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• 2011

In this paper, simulation works for a multi-stage cascade refrigeration cycle using propane, ethylene and methane as refrigerants have been performed for the liquefaction of natural gas using Peng-Robinson equation of state built-in PRO/II with PROVISION release 8.3. The natural gas feed compositions were supplied from Korea Gas Corporation and the flow rate was assumed to be 5.0 million tons per annual. Supply temperature for propane refrigerant was fixed as $-40^{\circ}C$, that for ethylene refrigerant as $-95^{\circ}C$, and that for methane refrigerant as $-155^{\circ}C$. For the multi-stage refrigeration cycle, three-stage refrigeration was assumed for propane refrigeration cycle, two-stage refrigeration for ethylene refrigeration cycle and three-stage refrigeration for methane refrigeration cycle. Natural gas was finally cooled and liquefied to $-162^{\circ}C$ by Joule-Thomson expansion. Conclusively, 91.71% by mole of the natural gas liquefaction ratio was obtained through a cascade refrigeration cycle and Joule-Thomson expansion and 0.433 kW of compression power was consumed for the liquefaction of 1.0 kg/hr of natural gas.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.6
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• pp.33-42
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• 2020

Emission factors for ammonia and particulate matters (PMs) from livestock buildings are of increasing importance in view of the environmental protection. While the existing emission factors were determined based on the emission inventory of other countries, in situ measurement of emission factors is required to construct an accurate emission inventory for Korea. This study is to report measurements of ammonia and PMs emissions from mechanically-ventilated pig houses, which are common types of pig barns in Korea. Ventilation rates and concentrations of ammonia and PMs were measured at the ventilation outlets of a weaner unit, a growing pig unit and a fattening pig unit to calculated the emission factors. The PMs emission was characterized with different aerodynamic diameters (PM_2.5, PM₁₀, and total suspended particulates (TSP)). The measured ammonia emission factors for weaners, growing pigs and fattening pigs were 0.225, 0.869 and 1.679 kg animal^-1 yr^-1, respectively, showing linear increase with pigs' age. The PMs emission factors for three growing stages were 0.023, 0.237 and 0.241 kg animal^-1 yr^-1, respectively for TSP, 0.017, 0.072 and 0.223 kg animal^-1 yr^-1, respectively for PM₁₀, and 0.011, 0.016 and 0.151 kg animal^-1 yr^-1, respectively for PM_2.5. PMs emissions were increased with pigs' age due to increasing feed supply and animal movement. The measured emission factors were smaller than those of the existing emission inventory indicating that the existing ones overestimate the emissions from pig buildings and also suggesting that long-term in situ monitoring at various livestock buildings is required to construct the accurate emission inventory.

• Journal of the Korean Society of Food Culture
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• v.3 no.4
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• pp.397-406
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• 1988

The changes in the dietary pattern of Koreans during the last one century and its consequences are summarized as follows; 1. Until the beginning of 20th century, Koreans used variety of cereals, vegetables and fruits for their staple food, but the variety has been largely reduced by the agricultural development and urbanized life style. 2. The well balanced traditional dietary pattern of Korean had been deeply deteriorated by the food shortage during the Japanese occupation and Korean war. 3. The deteriorated nutritional condition of Korean was not remedied by the restoration of traditional dietary pattern, but attempted to overcome it by the adoption of Western food habit. 4. The people were trained to eat milk and flour-meals during the starvation of Korean war, and it was continued after Korean war through the animal husbandry promotion policy. 5. The importation of food and feed cereals has been increased rapidly during the economic growth in 1970's and the food self-sufficiency droped below 50%. 6. In 1970's, the food supply pattern of Korean was restored to the level of early 1900, but the consumption of lipid increased extraordinarily. 7. The overconsumption of animal food and lipid continues in 1980's, and it coincides with the rapid increase in the occurence of food related degenerative deseases. 8. The establishment of Korean dietary goal which is based on the traditional dietary pattern is needed.

• Animal Bioscience
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• v.35 no.12
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• pp.1892-1903
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• 2022

Objective: A series of experiment were conducted to evaluate the effects of replacing a part of soybean meal (SBM) at 6% of broiler diets with fermented soybean meal (FSBM) obtained by single or two-stage fermentation by measuring growth performance, antioxidant activity in the jejunum and distal intestinal microflora. Methods: Soybean meal samples were prepared by single-stage fermentation using Bacillus velezensis (Bv) (FSBM_B), or Lactobacillus spp. (as commercial control) (FSBM_L). Additional SBM sample was prepared by two-stage fermentation using Bv and subsequently using Lactobacillus brevis ATCC 367 (Lb) (FSBM_B+L). Enzyme activity, chemical composition, trichloroethanoic acid-nitrogen solubility index (TCA-NSI) and antioxidant activity were measured. Then, in an in vivo study, 320 Ross308 broilers were divided into four groups with ad libitum supply of feed and water. Four groups were fed either a corn-soybean meal diet (SBM), or one of fermented SBM diets (FSBM_B+L, FSBM_B, and FSBM_L). Growth, serum characteristics, microflora, and the mRNA expression of selected genes were measured. Results: Compared to SBM, FSBM_B+L contained lower galacto-oligosaccharide, allergic protein, and trypsin inhibitor, and higher TCA-NSI by about three times (p<0.05). Reducing power and 1,1-diphenyl-2-picrylhydrazyl free radical scavenging ability correlated positively with the TCA-NSI content in FSBM. Growth performances were not significantly different among four groups. In jejunum of 35-day-old broilers, partial replacement of SBM by FSBM_B+L increased the activity of superoxide dismutase and catalase (CAT), and the FSBM_B group had the highest catalase activity (p<0.05). Partial replacement of SBM by FSBM increased relative mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and peptide transporter 1 (PepT1) (p<0.05); however, FSBM_B+L increased CAT mRNA level to 5 times of the control (p<0.05). Conclusion: Using Bv- and Lb-processed SBM through two-stage fermentation to partially replace 6% of diets will improve the gut's antioxidant activity under commercial breeding in broilers.

• Journal of agriculture & life science
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• v.50 no.5
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• pp.153-162
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• 2016

This study was conducted to investigate a proper management and nutrient supply for raising replacement heifers to improve lactating performance. In order to determine a proper TDN/CP ratio that would be suitable for domestic use, 13-month-old replacement heifers were fed in the ratios of 4.6:1(T1) and 4.3:1(T2), respectively, to examine the changes in nutritional intake, digestibility, characteristics of rumen fluid and blood compositions. While dry matter intake was same at 9.0kg/day, CP intake did not show any significant difference, though T2(1.45kg/day) was slightly higher than T1(1.34kg/day). In fiber intake and digestibility, two results showed no significant difference, though T1 was slightly higher than T2. The pH, NH3-N and VFA densities in rumen fluid examined at the fourth hour after feed intake did not show any significant difference either. Overall level of VFA was not influenced largely by the TDN/CP ratio, but the iso-butyrate and iso-valerate levels and the A/P ratio were significantly high in T1(p<0.05). In blood characteristics, the treatments showed no significant difference. In conclusion, the TDN/CP ratios of 4.3:1 and 4.6:1 did not significantly affect the characteristics of the ruminant stomach, but in comparison with digestibility of 13-month-old heifers, the ratio of 4.6:1 was more appropriate for increased intake of fiber and higher digestibility.

• Journal of the Korean Society of International Agriculture
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• v.23 no.5
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• pp.513-519
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• 2011

In recent, the cultivation of maize in the world is being increased as a feed for the animal due to the increase of the large amount of meat consumption. However, reduction of supply for the feeding maize by the natural disaster such as drought, flooding, and demanding materials for bioenergy are attributed to increase the cereal price of the world that caused for the fluctuation of prices. The research has been done to provide useful information to the Korean agricultural investor regarding the current status of maize production and distribution in Cambodia. The maize cultivation of Cambodia in 2009 presented as a second major crop at the area of 6.8% in the total crop production area, and it continuously increased maize production yearly basis for the internal uses as well as for the exportation. The total amount of production showed by amount of 0.92 million tons due to the increased production of unit area. The yield production of unit area in current shows about 4 tones per hectare. About 90% of total production produced during August to September at wet season, and area of Batambang province produced about 70% of the total production. The production of feeding maize cultivated about 70% of the total cultivation area, and the exportation have done around 60% and remains were consumed as a domestic uses. The prospects of maize production in Cambodia will be increased due to the acceleration of livestock industry as 8.7% of annual growth rate.

• Journal of Aquaculture
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• v.19 no.3
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• pp.173-177
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• 2006

This study was conducted to evaluate extruded pellets (EP) for growth of adult flounder by comparing with raw fish-based moist pellet (MP). Two replicate groups of 150 fish per each tank (initial mean weight 329 g) were fed one of seven EP (EP1, EP2, EP3, EP4, EP5, EP6 and EP7) and a MP for 8 months. Survival of fish fed the MP was not significantly different from that of fish fed the EP1, EP5 and EP7, but significantly higher than that of fish fed the EP2, EP3, EP4 and EP6 (P<0.05). Weight gain of fish fed the MP was significantly lower than that of fish fed the EPI (P<0.05), but not significantly different from that of fish fed EP2, EP3, EP4, EP5, EP6 and EP7. Feed efficiency of fish fed the MP was significantly lower than EP1, EP3, EP4, EP5 and EP6 (P<0.05), but not significantly different from that of fish fed EP2 and EP7 Feed supply (kg/tank) of fish fed the MP was significantly higher than that of fish fed all EP (P<0.05). Condition factor of fish fed the MP was not significantly different from that of fish fed all EP. The contents of moisture, crude protein and lipid in dorsal muscle and whole body was not significantly different among the groups. It is concluded that the dietary formulation used in the EP1, EP3, TP4, EP5 and EP6 can be applied in the practical extruded pellet feeds for adult flounder (329-680g).

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.4
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• pp.67-76
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• 2021

Biogasification is a technology that produces environmentally friendly fuel using methane gas generated in the process of stably decomposing and processing organic waste. Biogasification is the most used method for energy conversion of organic waste with high moisture content, and is a useful method for organic waste treatment following the prohibition of direct landfill (2005) and marine dumping (2013). Due to African Swine Fever (ASF), which recently occurred in Korea, recycling of wet feed is prohibited, and consumers such as dry feed and compost are negatively recognized, making it difficult to treat food waste. Accordingly, biogasification is attracting more attention for the treatment and recycling of food waste. Korea's energy consumption amounted to 268.41 106toe, ranking 9th in the world. However, it is an energy-poor country that depends on foreign imports for about 95.8% of its energy supply. Therefore, in Korea, the Renewable Energy Portfolio Standard (RPS) is being introduced. The domestic RPS system sets the weight of the new and renewable energy certificate (REC, Renewable energy certificate) of waste energy lower than that of other renewable energy. Therefore, an additional incentive system is required for the activation of waste-to-energy. In this study, the operation of an anaerobic digester that treats food waste, food waste Leachate and various organic wastes was confirmed. It was intended to be used as basic data for preparing the waste-to-energy incentive system through precise monitoring for a certain period of time. Four sites that produce biogas from organic waste and use them for power generation and heavy gas were selected as target facilities, and field surveys and sampling were conducted. Basic properties analysis was performed on the influent sample of organic waste and the effluent sample according to the treatment process. As a result of the analysis of the properties, the total solids of the digester influent was an average of 12.11%, and the volatile solids of the total solids were confirmed to be 85.86%. BOD and CODcr removal rates were 60.8% and 64.8%. The volatile fatty acids in the influent averaged 55,716 mg/L. It can be confirmed that most of the volatile fatty acids were decomposed and removed with an average reduction rate of 92.3% after anaerobic digestion.

• Journal of Mushroom
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• v.3 no.1
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• pp.1-23
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• 2005

World production of mushrooms has been increasing 10-20% every year. Recently, Pleurotus eryngii and P. nebrodensis are very popular as new mushroom species for cultivation. Two kinds of mushrooms, Gumji (Ganoderma) and Soji, were described in old book of Samguksagi (History of the three kingdoms; 1145) in Koryo-dynasty. Many kinds of mushrooms were also described in more than 16 kinds of old books during Chosun-dynasty in Korea. One hundred and sixty commercial strains of 25 species in mushrooms were distributed to cultivators. By the way, only 8 varieties of them have registered variety protection. Mushroom industry as important export products developed from 1960 to 1980. Production of mushrooms as food was 181,828 metric tons valued at 800 billion Korean won in 2003. Isolated and identified substances from mushrooms are promising antifungal, antiinflammatory, antitumor, antiviral (anti-HIV), antibacterial & antiparasitic, antidiabetic, immunomodulating, kidney tonic, hepatoprotective, nerve tonic, and sexual potentiator. These substances can also be used for blood pressure regulation and effective against cardiovascular disorders, hypocholesterolemia & hyperlipidemia, and chronicbronchitis. Mushroom products including pharmaceuticals, tonics, healthy beverages, functional biotransformants, and processed foods have also became available on the markets. Compost and feed can likewise be made from mushroom substrates after harvest. The mushroom industry is already one of the fastest growing investment sectors in Korea. By the way, there is a need to strain improvement for variety protection, advanced cultivation technology at low cost for growers, and control of demand and supply for marketing in order to more upgrade development of mushroom industry in the future.