• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.10
• /
• pp.998-1011
• /
• 2010

For preparing Korean lunar missions, an Earth-Moon transfer trajectory is designed and analyzed using finite thrust. To be a more realistic scenario, kick motor's performance which is used for TLI (Trans Lunar Injection) maneuver is assumed to have a certain maximum capability. Under this assumption, optimal Earth-Moon transfer trajectory analysis is made from the beginning of Earth departure to the final lunar closest approach. As a results, optimal Earth-Moon transfer trajectory solutions with finite thrust are compared to those of designed with impulsive thrust in previous study. It is confirmed that if the trajectory solutions derived with impulsive burn is directly applied to estimate the finite burn trajectory solutions, careful consideration for finite burn losses must be paid as for TLI maneuver. Presented algorithm and various results will give numerous insights into the future Korea's Lunar missions using finite thrust engines.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.36 no.12
• /
• pp.1163-1170
• /
• 2008

A mission scheduling optimization algorithm according to the purpose of satellite operations is developed using genetic algorithm. Satellite mission scheduling is making a timetable of missions which are slated to be performed. It is essential to make an optimized timetable considering related conditions and parameters for effective mission performance. Thus, as important criterions and parameters related to scheduling vary with the purpose of satellite operation, those factors should be fully considered and reflected when the satellite mission scheduling algorithm is developed. The developed algorithm in this study is implemented and verified through a comprehensive simulation study. As a result, it is shown that the algorithm can be applied into various type of the satellite mission operations.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.46 no.6
• /
• pp.496-502
• /
• 2018

In this study, experimental and analytical studies were carried out to observe the phenomenon of aerodynamic throat formed according to the primary flow and secondary flow momentum of the ejector. The equilibrium interval of the aerodynamic throat, which is the main variable of the ejector performance, was observed through the experiment using the cold flow experiment and the analysis using FLUENT. Performance characteristics were investigated by the change of the primary flow rate and the throat diameter of the ejector cylinder. As a result, the performance of the standard ejector was confirmed to be within the range of 0.33~1.167(off-design/design) and cylinder throat diameter range of 1~1.17(off-design/design area ratio).

• Journal of Food Hygiene and Safety
• /
• v.21 no.1
• /
• pp.31-35
• /
• 2006

This study was performed to evaluate the Quality characteristics of the beverage with Gastrodia elate Blume extract. In the sensory evaluation of Gastrodia elata Blume beverage, score of color, flavor, taste, and overall acceptability were the best for a mixing ratio of extract 50%, oligosaccharide 10%, citric acid 0.02%, apple juice 7%, and distilled water 32.98%. Brix and pH of Gastrodia elate Blume beverage were 16.97 and 4.27 Free sugars of Gastrodia elata Blume beverage were composed glucose (3417.72 mg/100g), fructose (2215.68 mg/100g), and sucrose (1615.68 mg/100g). Organic acids of Gastrodia elata Blume beverage were composed malic (472.60 mg/100g), citric (290.27 mg/100g), succinic (276.63 mg/100g), and fumaric acids (1.73 mg/100g).

• Journal of Food Hygiene and Safety
• /
• v.28 no.3
• /
• pp.252-257
• /
• 2013

In this study the automated technique TEMPO STA method, a new automated enumeration based on MPN method, was compared to the direct plate count method by testing various ready-to-eat compound food products. Artificially inoculated food samples with Staphylococcus aureus - Bibimbap, Bibimnaengmyeon, Mulnaengmyeon, Kimmaki, Salad, Japchae, and Sushi- were tested. Statistical analysis of the results showed above 99% in agreement between the two enumeration methods. Also, we monitored 466 various ready-to-eat compound food products samples. The measure uncertainties of the two methods is also familiar, while TEMPO STA automated method is simpler, less time-consuming, more effective and more stable.

• Food Science of Animal Resources
• /
• v.34 no.1
• /
• pp.49-56
• /
• 2014

The present study was carried out to investigate the effects of nanopowdered peanut sprout-added Caciocavallo cheese (NPCC) on the prevention and treatment of rheumatoid arthritis in DBA/IJ mice immunized with type II collagen. After the induction of arthritis, the mice were being divided into five groups: (1) normal, no immunization; (2) CIA, collagen-induced arthritis; (3) MTX, collagen-induced arthritis treated with methotrexate (0.3 mg/kg body weight); (4) CC, collagen-induced arthritis treated with Caciocavallo cheese (0.6 g/d); (5) NPCC, collagen-induced arthritis treated with nanopowdered peanut sprout-added Caciocavallo cheese (0.6 g/d). Nanopowdered peanut sprout was ranged from 300 to 350 nm, while regular powdered peanut sprouts were ranged from 50 to $150{\mu}m$. The NPCC group had considerable reductions of clinical scores and paw thicknesses at the end of experiment as compared to the CIA group. In the serum analysis, the TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and $IgG_1$ levels in the NPCC group have decreased by 69.4, 75.9, 66.6, and 61.9%, respectively, when compared to the CIA group. The histological score and spleen index of the NPCC group were significantly lower than the CIA group. In conclusion, the feeding NPCC method could delay and/or prevent the rheumatoid arthritis in the collagen-induced arthritis mouse model. Based on this study, nanopowdered peanut sprouts could be applied to various functional cheeses.

• The Journal of the Korea Contents Association
• /
• v.6 no.7
• /
• pp.58-68
• /
• 2006

There are two traditional scheduling methods known as PQ and WRR in the DiffServ network, however, these two scheduling methods have some drawbacks. In this paper, we propose an algorithm that can be adopted in WRR scheduler with making up for weak points of PQ and WRR. The proposed algorithm produces the control discipline by the fuzzy theory to dynamically assign the weight of WRR scheduler with checking the Queue status of each class. To evaluate the performance of the proposed algorithm, We accomplished a computer simulation using NS-2. From simulation results, the proposed algorithm improves the packet loss rate of the EF class traffic to 6.5% by comparison with WRR scheduling method and that of the AF4 class traffic to 45% by comparison with PQ scheduling method.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.25 no.1
• /
• pp.5-12
• /
• 2015

According to the analysis of special medical examination and work environment monitoring data, the rate of C1 and D1 on noise hazard exceeded 90 % among those of total hazardous factors. The rate of company exceeding noise exposure limit was also more than 90 %. The analysis result shows that main ages diagnosed with C1 and D1 was age of 50s. The majority scale company having workers diagnosed with C1 and D1 was the companies employing 5~49 workers. Types of industries which have a large number of companies exceeding noise exposure limit were automobile and trailer manufacturing, metal processing industry and primary metal manufacturing. A large number of work processes exceeding noise exposure limit were forming and processing work, cutting and bending work and grinding. To reduce the number of company exceeding noise exposure limit, the reduction counterplan should be focused on the type of industry and the work process which exceeded noise exposure limit frequently. However, the reduction counterplan is preemptively necessary to the type of industry and the work process which exceeded noise exposure limit consecutively if the purpose of reduction counterplan is not to merely reduce the number of company exceeding noise exposure limit but to abate workers' suffering from noise.

• Journal of Society of Preventive Korean Medicine
• /
• v.11 no.2
• /
• pp.159-174
• /
• 2007

Introduction : The experiments was undertaken to evaluate the effects of herbal medicine, Sibjeondaebotang, Yugmijihwangtang, in pregnant rats and fetuses. Female Sprague-Dawley rats were orally administered with the Sibjeondaebotang, Yugmijihwangtang at dose of 5mg/kg/day for 20 days. Pregnant rats were sacrificed at 20th day of gestation, and observed internal and reproductive organs. Approximately live fetuses in the 20th day of gestation were randomly selected and fixed in 95% ethanol. To observe skeletal malformations, fetuses were stained with alcian blue and alizarin red S. Effect on pregnant rats : Maternal body weight of Sibjeondaebotang, Yugmijihwangtang treated group has a tendency to increase compared to that of control group. There were no significant difference in internal and reproductive organs. There were no significant changes between two groups in blood chemistry and hematological values. There were no significant changes in number of corpus luteum, implantation, live fetuses and implantation rate, delivery rate, and sex ratio. But Yugmijihwangtang administered group showed higher early resorption rate than the control group(p<0.05). Also Sibjeondaebotang administered group showed higher late resorption rate than the control group(p<0.05). From the sex ratio, number of females, bigger than number of males in the control group, and more males than females in Yugmijihwangtang administered group(p<0.05).

• Journal of Society of Preventive Korean Medicine
• /
• v.11 no.1
• /
• pp.23-34
• /
• 2007

Health promotion program utilizing traditional korean medicine(TKM) is very unique modality uncommonly conducted throughout the world. Korea's TKM public health services went through initial stage from 2001 and spread throughout the country by 2003. 35 public health centers in the nation is appointed as 'TKM health promotion HUB' and in operation from 2007. But the program is still in the early state and evaluation of usage, satisfaction, and community service is still in demand. This study aims to verify current situations of TKM public health service by examining public awareness, usage, and satisfaction and suggest improvements based on findings. 2.5% of local residents were sampled and 1739 were chosen as subjects. Knowledge, attitude, satisfaction and others for TKM public health service were examined. TKM treatment service was most widely utilized(13.2%), followed by CVA prevention program(5.2%). For satisfaction level, CVA prevention program showed highest satisfaction(73.3%), closely followed by (Qi-gong program 63%). In general, awareness and utilization of TKM public health service were low but compensated by high satisfaction level. More active promotion and development of community specific programs should become available in the future.