• Journal of the Korean Society for Aviation and Aeronautics
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• v.27 no.2
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• pp.16-25
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• 2019

While various efforts are being made to ensure aviation safety, air accident rate induced by pilot human factors is still high worldwide. In particular, among pilot human factors, it would be the most important issue for pilots to anticipate and recognize flight environmental factors beyond their control and to make a positive decision making(ADM). In the Republic of Korea Air Force(ROKAF), there were many dizzying experiences induced by bird strike incidents and developed into dangerous moments such as damage to the aircraft and pilots' increased mental stress. It is a matter of serious concern in terms of safety management and human factors to dismiss bird strike incidents as inevitable misfortune due to environmental factors. In 2018, the ROKAF Aviation Safety Agency(ASA) conducted an experimental study to enhance pilots' ADM competence that can anticipate and avoid a bird strike. As the way of the study, 'Bird Strike Preventing Information' had been written and distributed every week by the ASA to flight units in the ROKAF during the period of the study. Through enhanced pilots' perceptual ADM competence, there was a noticeable number of reduction in bird strike incident compared to previous years of the experimental study.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.7 no.1
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• pp.20-26
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• 1996

The purposes of this study were to analyze the sound of bird's frequency region and pattern and to discuss hearing impaired children's auditory discrimination. The results were ie follows; 1) The sounds of bird's frequency region were divided into Low(below 1, 000Hz), Mid(between 1, 000 and 4, 000Hz) and High(between 2, 000 and 4, 000Hz). 2) The sounds of bird, which were same, long, high pattern, were in Mid ＆ High. Short and high pattern were above High.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.1
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• pp.91-95
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• 1990

We study the process for the reduction of bird's beak at LOCOS processing with changing the representative coefficients, oxide thickness, silicon nitride thickness, oxidetion temperature and field oxide thickness that induced the condition of bird'beak. In order to eliminate the gate oxide defects induced by selective oxidation, we used additional sacrific oxidatio. Finally we obtained the length of bird's beak to be 5000\ulcornerby SEM.

• Journal of Wetlands Research
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• v.19 no.2
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• pp.223-229
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• 2017

This study analyzed the relationship between environmental factors and the temporal changes of the bird populations during the every January from 1999 to 2016 (18 years) in Donglim reservoir. 'Winter Waterbird Census of Korea' data by National Institute of Biological Resources were used for the bird population data, and principal component analysis and cluster analysis were used to analyze the changes of annual population. The average temperature of January and the average storage rate of the reservoir were used as environmental factors. According to the results of the study, the population changes in the study area can be explained by the increase and decrease of two water bird groups and a mountain bird group. The average temperature of the years when the population of water bird groups increased was more than $1.4^{\circ}C$ in comparison with the year when mountain birds increased. On the other hand, the influence of the water content was not clear. The visiting of Baikal Teal affected by temperature was a factor affecting the other group of water bird and a mountain bird group. The results of this study suggest that the temperature change affects the global spatial distribution of birds and the migration of large population species such as Baikal Teal affects species composition and populations of birds at local scale. Therefore, understanding of environmental changes at large scale and spatial distribution of species and flock contributes to understand the temporal variation of the bird population at regional or local scales.

• Korean Journal of Environment and Ecology
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• v.14 no.2
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• pp.103-110
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• 2000

This study was conducted to investigate the effect of trails on breeding bird community by territory mapping method from April to August 1999 in Chirisan National Park. Twenty-five bird species were observed and 18 bird species bred in 4 study sites. Thirteen species bred in Imgullyung site 14 species in Imgullyung trail site 14 species in the Nogodan site and 15 species in the Nogodan trail site. There were bred 62.0 pairs of birds in the Imgullyung site 55.0 pairs in the Imgullyung trail site 36.5 pairs in the Nogodan site and 36.5 pairs in the Nogodan trail site in the breeding season 1999. There were no differences in breeding bird communities among 4 sites. The nesting and foraging guild structures were similar among 4 sites. It seems that trails do not influences on the breeding bird community becasuse the canopy layer was similair and connected and understory vegetation was developed around the trails. It would be needed the maintenance and management of canopy layer and understory vegetation for the protection and management of bird communities around the trails.

• Journal of Aerospace System Engineering
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• v.13 no.6
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• pp.70-79
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• 2019

The increase of bird strike requires to be amended more safely current airworthiness requirements for bird strike. The USA and Europe are considering the methodology to verify the bird strike requirements based on the finite element analysis (FEA). Meanwhile, the aircraft airworthiness standards in Korea enacted by the Ministry of Land, Infrastructure and Transport were based on those enacted by the Federal Aviation Administration (FAA). This means that the verification methods using the FEA for the bird strike requirements should be reflected in the airworthiness standards in Korea. Our study proposes the methodology for bird strike simulation based on the FEA for the external auxiliary fuel tank assembly on the Surion helicopters and confirmed that the numerical outputs corresponded to the test results. The authors suggest that the methodology and procedure based on the FEA are adopted not only in the bird strike requirements but in various aircraft certifications of civilian rotorcraft.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.267-274
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• 1992

In order to study the relationships between the contents of urinary nitrogenous compounds and energy utilization of bird, the sum of nitrogen contents of uric acid, ammonia, creatine and urea voided in excreta was estimated as the urinary nitrogen (UN) in 13-33 day-old fed or fasted White Leghorn male chicks. Energy retention and heat production of birds were determined by comparative slaughter studies. 2.75 mg of endogenous urinary nitrogen (EUn) and 2.19 mg of uric acid was excreted constantly per kJ heat production in fasted bird. One mg of UN was proportionated to 32.26 J (r = 0.999, n = 8) of the urinary energy (UE) in fed and 32.97 J (r = 0.9998, n = 8) of the endogenous urinary energy (UEn) in the fasted bird. Also relationships between 1 mg of uric acid and 38.95 J of UE (r = 0.998, n = 8) or 38.97 J of UEe (r = 0.996, n = 8) were significant (p<0.01). The EUn (r = 0.997, n = 4), uric acid (r = 0.995, n = 4) and metabolic fecal energy (FEm) plus UEe (r = 0.961, n = 4) were increased with the increase of body weight (g/bird). Metabolic fecal nitrogen (MFn) or energy (FEm), EUn and UEe per unit diet were not influenced by the age of day or body weight. The results indicated that energy and protein utilization of bird can be approximated by the relationships among urinary nitrogen, urinary energy, uric acid content in excreta and body weight of bird.

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.32-35
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• 2009

A new poinsettia cultivar "Early bird" was bred by the National Institute of Horticultural and Herbal Science (NIHHS) in 2007. A cross was made between 'Ichiban', a variety with deep lobed transitional leaves and bright red bracts, and 'Freedom Red', a vigorously growing dark red colored variety in 2004. "Early bird" was finally selected in 2007 after the investigation of the growth and flower characteristics from 2005 to 2007. "Early bird" has bright red colored, wide obovate bracts. Leafblade is dark green and ovate. Plant height is short and stem color is greenish. Response to short day is early and its bracts and transitional leaves are fully colored 6.5 weeks after short day commencement.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.416-419
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• 1987

The miniaturization of Bird's Beak generated at the field oxidation has been studied by adding polysilicon layer between the silicon nitride and pad oxide stack, which is the basic structure of Conventional LOCOS. The size and shape of Bird's Beak were intensively observed by SEM, and also the electrical characteristics of Bird's Beak-reduced LOCOS structure were compared with those of Conventional LOCOS. The length of Bird's Beak was reached up to $0.20-0.28{\mu}m$, while about to $0.50-0.53{\mu}m$ in conventional LOCOS, resulting in 60% reduction.

• Journal of Ecology and Environment
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• v.32 no.3
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• pp.137-143
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• 2009

Pre-dispersal seed predation by a granivorous bird, the masked grosbeak (Eophona personata, Fringillidae), was investigated in two bird-dispersed trees, Celtis sinensis and Aphananthe aspera (Ulmaceae). The objectives of this study were to 1) measure direct damage of predation by grosbeaks on plant crops, 2) reveal the temporal pattern of predation within each tree species and its causal factors, and 3) test whether foraging grosbeaks hinder foraging of frugivorous birds, thereby indirectly impacting the reproduction of both tree species. A substantial amount of fruit and seed crop was consumed by grosbeaks (24.3% in Celtis; 55.5% in Aphananthe), and only 17.7% (Celtis) and 16.7% (Aphananthe) were removed by frugivorous birds. At the study site, the grosbeak population size fluctuated greatly during the fruiting seasons of both plant species. As for Celtis, predated seed density also fluctuated temporally, and the local population size of grosbeaks was responsible for predated seed density. In Aphananthe, predation was not fully explained by grosbeak populations or plant phenology, but its peak coincided with that of grosbeak population. These results suggest that predispersal seed predation by granivorous birds can have large negative impacts on the bird-dispersed plants. Changes in local population size of granivorous birds can influence predatation and can affect reproductive success of the bird-dispersed plants available to the birds.