• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.546-549
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• 2004

The T-50/A-50 Golden Eagle was developed for a supersonic trainer and light combat aircraft. At the design stage, vibration control plans were established and applied. For cockpit vibration, crew comfort vibration level was defined by the requirement of MIL-A-8892. It is found that the T-50/A-50 meets the requirement of cockpit vibration from the flight test data analysis. This paper contains the results of cockpit vibration analysis using the flight test data and the results of human vibration analysis lot the pilot inside aircraft. The human vibration level of pilot is increased as dynamic pressure is increased and at the specific high dynamic pressure, the ride comfort indicates 'a little uncomfortable'. Overall analysis results show that the vibration level of T-50/A-50 cockpit is tolerable and not critical for pilot's comfort.

• Journal of the Korean Society for Aviation and Aeronautics
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• 제28권1호
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• pp.90-105
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• 2020

This research investigates the export strategy for pioneering a new market of Advanced Pilot Trainer T-50, a business unit of KAI company, and increasing its market share. The export strategy is proposed based on the Corporate Marketing Model along with the market oriented concept. Specific sales strategies are extracted in consideration of product analysis, market analysis, and integration of product and target market. Therefore, six countries in Africa are selected as the primary target markets on account of their market potentials. In addition, T-50 is repositioned to 'T-50Af' as 'high price competitive and multi-role trainer.' The business implications include the expansion of the market in Africa and the pursuit of the consistent development and growth of T-50.

• Asian Journal of Atmospheric Environment
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• 제4권1호
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• pp.33-41
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• 2010

Because ammonia from livestock production may substantially contribute to environmental pollution, emissions from all possible sources (housing systems, manure storage, manure application, outside grazing) should be reduced. The purpose of this study was to investigate the effect of different bedding materials on ammonia emissions in a cow house. By applying a combination of four treatment types: treatment $1-T_1$ (sawdust (50%)+sawdust pellets (50%)), treatment $2-T_2$ (sawdust (50%)+corn stalk pellets (50%)), treatment $3-T_3$ (sawdust (100%)), and treatment $4-T_4$ (sawdust (50%)+palm kernel meal pellets(50%)) as bedding materials in a cow house, the effects of such treatments on ammonia flux were assessed in approximately one month. The magnitude of ammonia emissions (mg $m^{-2}\;min^{-1}$) varied in the following order: $T_1$(2.226), $T_4$(2.052), $T_2$(1.845), and $T_3$(1.712). The patterns of pH had a decreasing trend for all bedding treatments during the experiment, and there was no significant relationship with ammonia flux. The results reveal that the most important factor influencing ammonia emissions is the physical structure of the bedding types.

• Asian-Australasian Journal of Animal Sciences
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• 제18권10호
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• pp.1492-1497
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• 2005

The goal of the trial was to evaluate the effects of ractopamine (20 ppm in the ration) given pregnant sows during three different pregnancy stages (T1: 25 to 50 d; T2: 50 to 80 d; T3: 25 to 80 d of gestation, and T4: control-no ractopamine) on fetal muscle development (through counts of the number of fibers of the semitendinosus muscle), on the growth and carcass characteristics of the progeny. Forty eight weaned piglets (12 per treatment) were assessed for number of muscle fibers, while performance and carcass characteristics were evaluated on a separate 48 animals (12 per treatment) grown to 100 kg. Animals produced by sows treated from 25 to 50 d of pregnancy (T1) resulted in non-significant increase of 6.85% in the number of muscle fibers in the semitendinosus muscle when compared to animals from the control group. Performance results were significantly different (p<0.05), and animals produced by sows from the T1 group gained more weight during the growth I stage (25 to 50 kg) and during the total period (6 to 100 kg) (991 vs. 903 grams, and 844 vs. 772 grams, respectively) when compared to controls. For carcass characteristics, results showed that animals produced by the T1 group of sows were heavier at slaughter (p<0.05) when compared to the controls (T4) (100.17 vs. 93.09 kg). There was a positive correlation between number of muscle fibers and bodyweights, carcass weights, Longissimus dorsi muscle depth and dressing out (0.80, 0.86, 0.67, and 0.50, respectively). Sows treated with ractopamine between 25 to 50 d of pregnancy produced piglets that performed better and had superior carcass characteristics than those produced by untreated sows. The ractopamine used for pregnancy sows (25 to 50 d) can be indicated as a device to increase the progeny performance.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 추계 학술대회논문집
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• pp.131-135
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• 2006

The aerodynamic characteristics of a T-50 aircraft configuration are investigated by a subsonic panel method. Panel methods are best applicable to the lifting surfaces such as wings and airfoils. Source and doublets are used in the present code as a basic singularities of the panel technique. The panel method is first assessed by applying it to several benchmark problems for which other solutions and experimental data are available, such as a swept wing and wing body configuration. The prediction results are compared with experimental data and show good agreement in all cases considered. Finally, the method is applied to a T-50 aircraft configuration and excellent agreement with flight test data in lift coefficients is found.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제33권5호
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• pp.57-64
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• 2005

Modern versions of supersonic jet fighter aircraft using digital flight-by-wire flight control system receive aircraft flight condition such as altitude, airspeed and AoA(angle of attack) from IMFP(Integrated Multi-Function Probe). IMFP sensors data have triplex structure using three IMFP sensors. An air data reconfiguration mode is applied to a T-50 flight control law to guarantee the aircraft flight stability when 2 or 3 IMFP sensors data are invalided. In this study, linear analysis and HQS(Handling Quality Simulator) pilot simulation are performed to analyze flight stability when the air data reconfiguration mode is applied to the control law. And we propose an example that the air data reconfiguration mode is applied to the control law due to second failure of IMFP during T-50 flight. It is found that the aircraft flight stability is not affected when the T-50 flight control law is changed to the air data reconfiguration mode.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• 제59권3호
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• pp.189-195
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• 2023

This study quantitatively evaluated size selectivity for three netting shapes (T0; regular, T45, T90) and hanging ratio (35%, 70%) of T0 netting used for trawl codend. The size selectivity experiment was performed in a tank using a cube experimental model with a length of 50 cm on one side and 389 experimental individuals, jack mackerel (Trachurus japonicus). In the selectivity analysis, a selectivity curve was created based on the selection ratio using a logistic function, and the 25%, 50%, and 70% selection length and selection range (SR) were obtained. The T0 netting was 19.54 cm when the 50% selective length, which is a selectivity evaluation index, had a hanging ratio of 35%, a selection range of 0.51 cm, and 22.70 cm and 3.08 cm for the hanging ratio of 70%. The T45 netting was 24.34 cm and 2.13 cm, and the T90 netting was 23.51 cm and 2.84 cm. The results of the T45 netting and the T90 netting are similar, and the 50% selection length and selection range were relatively larger than the T0 netting. There was a significant difference in the correlation between the circumference of the inner circle of the mesh by the shape of the netting and the body girth of the experimental individual (Pearson test, r = 0.86, p < 0.05). There was no significant difference in the correlation between the selection ratio by the T0 netting, T45 netting, and T90 netting with a 70% hanging ratio (one-way ANOVA, p > 0.05). The results of this study showed that selectivity such as T45 netting and T90 netting appeared when the hanging ratio, which maximizes the area of T0 netting, was maintained at 70%.

• Journal of Environmental Science International
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• 제28권1호
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• pp.1-6
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• 2019

Ptecticus tenebriferwas incorporated to partially or totally replace the diets of juvenile white shrimp (Litopenaeus vannamei). Experimental groups of shrimp with an average initial body weight of $0.014{\pm}0.001g$ were fed each of the 5 diets formulated to include 0, 25, 50, 75, and 100% (C, T25, T50, T75, and T100, respectively) of Ptecticus tenebriferpowder substituted for commercial feed. After eight weeks of feeding trials, juvenile shrimp fed with diets T25 and T50 showed higher live weight gain ($2.298{\pm}0.405$ and $2.539{\pm}0.406$, respectively), and a better feed conversion ratio ($1.389{\pm}0.246$ and $1.536{\pm}0.246$, respectively) compared to those of shrimp fed a control diet. Survival rate was 98% in all experimental groups except for the T75 group ($66.67{\pm}57.73%$ survival). The levels of immune markers such as beta-glucan binding protein, prophenoloxidase, and crustin associated with the cellular and humoral immunity of shrimp were found to be higher in 25% and 50% commercial feed replacement groups. A reduction in total nitrogen, nitrite nitrogen, and ammonia levels was greater in T25 and T50 rather than in T75 and T100. These results clearly indicate that replacement of feed with 25 to 50% Ptecticus tenebriferpowder in juvenile white shrimp diet was optimal in promoting the growth performance of shrimp without any adverse effects.

• Journal of the East Asian Society of Dietary Life
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• 제25권1호
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• pp.176-182
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• 2015

The aim of this study was to evaluate the characteristics of muffin made with tagatose which substituted sugar. Moisture contents were measured and Texture Profile Analysis was carried out during 3 day storage. 3 types of muffin, T0 (no tagatose added, sugar was the only sweet taste source), T25 (tagatose : sugar = 25:75(w/w), and T50 (tagatose : sugar = 50:50(w/w) were prepared. As the tagatose contents increased, the Maillard reaction proceeded more, so the color of the muffin crust was darker. Moisture contents of muffins decreased during storage, up to 2 days of storage, moisture contents of T25 and T50 were higher significantly, but at the 3rd day of storage, no differences were detected among samples. In the texture profile analysis, hardness, chewiness and fracturability were higher as the tagatose contents increased. Springiness and cohesiveness did not show any differences between T0 and T25 significantly. In the sensory evaluation, T0 got the lower points on the crust color value, but the crust colors were not significantly different among samples. Other characteristics like crumb color, moistness, sweetness, flavor and overall acceptance were not different significantly. As a result, when synbiotic and low-calorie tagatose was partly added to muffin up to 50 % as sugar substitute, overall qualities of those muffins were not different with only sugar added ones, even moisture contents were higher but color was a little bit darker, so tagatose can be used on making healthy muffins successfully.

• Journal of Environmental Science International
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• 제31권11호
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• pp.989-992
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• 2022

This study was conducted to investigate the efficacy of larval stages of three species, namely, Tenebrio molitor, Protaetia brevitarsis seulensis, and Ptecticus tenebrifer larvae, in degrading poultry manure, specially, broiler and duck manure. The survival rates of larvae were also noted. For the experiment, T. molitor (n=300), P. brevitarsis seulensis (n=60), and P. tenebrifer (n=300) hatched larvae were randomly divided into six groups with three replicates. The degaradation efficacy tests were then performed for 30 days in a laboratory. The test groups were as follows: T1, 110 g broiler manure + T. molitor larvae (n=50); T2, 110 g duck manure + T. molitor larvae (n=50); T3, 125 g broiler manure + P. brevitarsis seulensis larvae (n=10); T4, 125 g duck manure + P. brevitarsis seulensis larvae (n=10); T5, 105 g broiler manure + P. tenebrifer larvae (n=50); and T6, 105 g duck manure + P. tenebrifer larvae (n=50). The groups showed significant efficacy in degrading broiler and duck manure (p<0.05). The highest survival rates were recorded for T. molitor larvae in both manure types [T1 (92.67%) and T2 (50%)], followed by P. brevitarsis seulensis larvae (T4, 40%) and P. tenebrifer larvae (T6, 14.67%) in duck manure. Next, the survival rates of P. brevitarsis seulensis (T3) and Ptecticus tenebrifer larvae (T5) in broiler manure were 0%. In conclusion, these results point to the feasibility of using insect larvae to degrade broiler and duck manure.