• Asian-Australasian Journal of Animal Sciences
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• 제32권6호
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• pp.815-825
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• 2019

Objective: To effectively use corn stover resources as animal feed, the changes in microbial population and chemical composition of corn stover during field exposure, and their silage fermentation and in vitro digestibility were studied. Methods: Corn cultivars (Jintian, Jinnuo, and Xianyu) stovers from 4 random sections of the field were harvested at the preliminary dough stage of maturity on September 2, 2015. The corn stover exposed in the field for 0, 7, 15, 30, 60, 90, and 180 d, and their silages at 60 d of ensiling were used for the analysis of microbial population, chemical composition, fermentation quality, and in vitro digestibility. Data were analyzed with a completely randomized $3{\times}6$ [corn stover cultivar $(C){\times}exposure$ d (D)] factorial treatment design. Analysis of variance was performed using SAS ver. 9.0 software (SAS Institute Inc., Cary, NC, USA). Results: Aerobic bacteria were dominant population in fresh corn stover. After ensiling, the lactic acid bacteria (LAB) became the dominant bacteria, while other microbes decreased or dropped below the detection level. The crude protein (CP) and water-soluble carbohydrate (WSC) for fresh stover were 6.74% to 9.51% and 11.75% to 13.21% on a dry matter basis, respectively. After exposure, the CP and WSC contents decreased greatly. Fresh stover had a relatively low dry matter while high WSC content and LAB counts, producing silage of good quality, but the dry stover did not. Silage fermentation inhibited nutrient loss and improved the fermentation quality and in vitro digestibility. Conclusion: The results confirm that fresh corn stover has good ensiling characteristics and that it can produce silage of good quality.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2003년도 정기총회 및 추계학술대회
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• pp.181-187
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• 2003

This study intends to make a counterproposal for re-building existing high-rise/high-dense buildings and for planlessly re-constructing multi-dwellings. Also, it proposes the plan instruction fur reconstruction by small collective housings through annexing parcels in the residence Inner area. This study can be summarized as below: (1) Remained site generated by site boundaries can be utilized by annexing two or more parcels. (2) Vacant lots between buildings can be utilized as building space or common space by small-sized annexation. (3) Bad effect of residential environment caused by simultaneous development of total blocks can be minimized. (4) Formation of site size and plane, which are advantageous to reconstruction, is available. (5) Accessibility to neighboring roads can increase. (6) Residents' participation in development can increase in economical and planning aspect. In order to utilize these planning instruction, residents' participation and improved public ownership system for parcel annexation are required.

• Journal of Astronomy and Space Sciences
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• 제31권1호
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• pp.7-13
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• 2014

Variabilities in the solar wind cause disturbances throughout the heliosphere on all temporal and spatial scales, which leads to changeable space weather. As a view of space weather forecasting, in particular, it is important to know direct and indirect causes modulating the space environment near the Earth in advance. Recently, there are discussions on a role of the interaction of the solar wind with Mercury in affecting the solar wind velocity in the Earth's neighborhood during its inferior conjunctions. In this study we investigate a question of whether other parameters describing the space environment near the Earth are modulated by the inner planets' wake, by examining whether the interplanetary magnetic field and the proton density in the solar wind observed by the Advanced Composition Explorer (ACE) spacecraft, and the geomagnetic field via the Dst index and Auroral Electrojet index (AE index) are dependent upon the relative position of the inner planets. We find there are indeed apparent variations. For example, the mean variations of the geomagnetic fields measured in the Earth's neighborhood apparently have varied with a timescale of about 10 to 25 days. Those variations in the parameters we have studied, however, turn out to be a part of random fluctuations and have nothing to do with the relative position of inner planets. Moreover, it is found that variations of the proton density in the solar wind, the Dst index, and the AE index are distributed with the Gaussian distribution. Finally, we point out that some of properties in the behavior of the random fluctuation are to be studied.

• Asian Journal of Atmospheric Environment
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• 제11권2호
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• pp.131-137
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• 2017

A cyclone is an effective tool to facilitate the collection of aerosol particles without using filters, and in cell exposure studies is able to collect a sufficient amount of aerosol particles to evaluate their adverse health effect. In this study, we examined two different methods to improve the aerosol particle collection efficiency of a cyclone. The individual and combined effects of reducing the surface roughness of the inner wall of the cyclone and of using a circular cone attachment were tested. The collection efficiency of particles of diameter $0.2{\mu}m$ was improved by approximately 10% when using a cyclone with a smoothened inner wall (average roughness $Ra=0.08{\mu}m$) compared with the original cyclone ($Ra=5.1{\mu}m$). A circular cone attachment placed between the bottom section of the cyclone and the top section of a collection bottle, resulted in improved collection of smaller particles without the attachment. The 50% cutoff diameter of the modified cyclone (combined use of smoothened inner wall and attachment) was $0.23{\mu}m$ compared to $0.28{\mu}m$ in the original model. The combined use of these two techniques resulted in improved collection efficiency of aerosol particles.

• 생물환경조절학회지
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• 제29권3호
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• pp.285-292
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• 2020

본 연구에서는 CFD 시뮬레이션 기법을 이용하여 유리온실의 내부 환경 변화를 예측하는 모델을 개발하였으며, 실험을 통해 확보한 데이터를 이용하여 이를 검증하였다. 주·야간 실험 데이터를 경계조건으로 하는 Case 1, 2, 3의 시뮬레이션 예측값은 실험값 대비 평균 2.62℃ 높게 나타났으며, 최대편차와 균일도는 각각 평균 1.12℃, 2.92%p 높게 나타났다. Case 1에서 Case 3으로 외기온도가 변화함에 따라 조성되는 온실 내부 온도는 평균 0.84℃의 차이를 보였으며, R²는 0.9628로 실험값과 시뮬레이션 예측값 간 유사한 경향을 보임을 확인하였다. 시뮬레이션 예측 결과 해석대상 온실 내 불균일한 온도분포를 확인하였다. 해석대상 온실의 효율적인 열에너지 관리를 위해 온실 내 방열관과 FCU의 위치 변경, 온실 구조 변경 등이 필요하다고 판단되었다. 추후 현장에서의 적용을 위해 정밀한 분석이 필요하며 이를 위해 온실 내부 작물 및 구조물 미고려, 온실을 완전 밀폐로 가정하는 등 모델 정립을 위한 조건들에 의한 열전달 현상을 고려한 모델의 개선이 필요하다고 판단된다.

• 인간식물환경학회지
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• 제23권1호
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• pp.101-114
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• 2020

This study focused on the composition of the exterior space of Parkjinsagoga, the types of gardens and planting and the landscape characteristics of walls, and examined its meaning as modern garden remains. Parkjinsagoga is a modern Korean house that harmonizes traditionality and practicality, and is an invaluable material for research not only on architecture but also on changes in the gardens of upper-class gardens. Its exterior space can be divided largely into An-chae (inner house), Outer Sarang-chae (outer house) and Inner Sarang-chae areas, and a garden was created in each yard (inner garden). In particular, one thing noticeable is that the yard of Inner Sarang-chae, unlike traditional gardening styles, was actively decorated. At the center of the yard of Inner Sarang-chae, two atypical planters and artificial moundings were created and the traffic line of the garden was designed to enjoy them while walking. An atypical pond was created on one of the artificial moundings and trees and shrubs were densely planted. Natural stones were also placed. The style seemed to be affected by Japanese gardens. These characteristics observed in the gardens of Parkjinsagoga are closely related to the transitional characteristics that traditional gardens started to show in modern times. A total of 35 families and 57 species were planted in the gardens of Parkjinsagoga and there were 19 species of tall trees, 20 species of shrubs and 17 species of flowering plants. The number of species planted in the garden of Inner Sarang-chae was the highest, and a total of 22 species of tall trees and shrubs. The walls in Parkjinsagoga were basically earth and rock-fill walls but their materials and patterns differed depending on the type of spaces. Four types of walls were found to be introduced to the house.

• Asian-Australasian Journal of Animal Sciences
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• 제29권9호
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• pp.1345-1352
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• 2016

The hindgut of horses is an anaerobic fermentative chamber for a complex and dynamic microbial population, which plays a critical role in health and energy requirements. Research on the gut microbiota of Mongolian horses has not been reported until now as far as we know. Mongolian horse is a major local breed in China. We performed high-throughput sequencing of the 16S rRNA genes V4 hypervariable regions from gut fecal material to characterize the gut microbiota of Mongolian horses and compare them to the microbiota in Thoroughbred horses. Fourteen Mongolian and 19 Thoroughbred horses were used in the study. A total of 593,678 sequence reads were obtained from 33 samples analyzed, which were found to belong to 16 phyla and 75 genera. The bacterial community compositions were similar for the two breeds. Firmicutes (56% in Mongolian horses and 53% in Thoroughbred horses) and Bacteroidetes (33% and 32% respectively) were the most abundant and predominant phyla followed by Spirochaete, Verrucomicrobia, Proteobacteria, and Fibrobacteres. Of these 16 phyla, five (Synergistetes, Planctomycetes, Proteobacteria, TM7, and Chloroflexi) were significantly different (p<0.05) between the two breeds. At the genus level, Treponema was the most abundant genus (43% in Mongolian horses vs 29% in Thoroughbred horses), followed by Ruminococcus, Roseburia, Pseudobutyrivibrio, and Anaeroplasma, which were detected in higher distribution proportion in Mongolian horses than in Thoroughbred horses. In contrast, Oscillibacter, Fibrobacter, Methanocorpusculum, and Succinivibrio levels were lower in Mongolian horses. Among 75 genera, 30 genera were significantly different (p<0.05) between the two breeds. We found that the environment was one of very important factors that influenced horse gut microbiota. These findings provide novel information about the gut microbiota of Mongolian horses and a foundation for future investigations of gut bacterial factors that may influence the development and progression of gastrointestinal disease in horses.

• Asian-Australasian Journal of Animal Sciences
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• 제30권6호
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• pp.788-796
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• 2017

Objective: In order to improve fermentation quality of natural grasses, their silage preparation and fermentation quality in meadow steppe (MS) and typical steppe (TS) were studied. Methods: The small-scale silages and round bale silages of mixed natural grasses in both steppes were prepared using the commercial lactic acid bacteria (LAB) inoculants Chikuso-1 (CH, Lactobacillus plantarum) and cellulase enzyme (AC, Acremonium cellulase) as additives. Results: MS and TS contained 33 and 9 species of natural grasses, respectively. Stipa baicalensis in MS and Stipa grandi in TS were the dominant grasses with the highest dry matter (DM) yield. The crude protein (CP), neutral detergent fiber and water-soluble carbohydrate of the mixed natural grasses in both steppes were 8.02% to 9.03%, 66.75% to 69.47%, and 2.02% to 2.20% on a DM basis, respectively. All silages treated with LAB and cellulase were well preserved with lower pH, butyric acid and ammonia-N content, and higher lactic acid and CP content than those of control in four kinds of silages. Compared with CH- or AC-treated silages, the CH+ AC-treated silages had higher lactic acid content. Conclusion: The results confirmed that combination with LAB and cellulase may result in beneficial effects by improving the natural grass silage fermentation in both grasslands.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.469-472
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• 2006

The primary objective of this study was to gain insight into the characteristics of algal blooms in relation to the marine environment of the Korean Southern Coast, using more than 22 years worth of data since the first known occurrence of algal blooms. Algal blooms tend to occur when the precipitation or water temperature for a ten-day period prior to the annual bloom exceeds the long-term mean value. There are three notable causative species in six different inner bays, namely Prorocentrum sp., Skeletonema costatum, and Heterosigma akashiwo, and in addition, these three species appeared in different conditions of water temperature and salinity at each region.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.273-278
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• 2006

In order to use a GPS antenna for launch vehicles, it should be installed on the skin of the vehicle and be able to normally receive the live GPS signals during the vehicle's full flight mission. The GPS antenna on the surface of the launch vehicle is, however, exposed to higher temperature than inner equipments of the vehicle due to aerodynamic heating generated during the flight. Test specification of the GPS antenna for qualification of hot-temperature is determined to $+95^{\circ}C$ that is higher than inner components by $25^{\circ}C$. Test results in this paper show that the GPS antenna normally operates under the above environment.