• 대한원격탐사학회지
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• 제19권3호
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• pp.181-190
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• 2003

Since the operation of the first satellite-based navigation service, satellite positioning has played an increasing role in both surveying and geodesy, and has become an indispensable tool for precise relative positioning. However, in some situations, e.g. at a low angle of elevation, the use of satellites for navigation is seriously restricted because obstacles like buildings and mountains can block signals. As a mean to resolve this problem, the quasi-zenith satellite system has been proposed as a next-generation satellite navigation system. Quasi-zenith satellite is a system which simultaneously deploys several satellites in a quasi-zenith geostationary orbit so that one of the satellites always stay close to the zenith if viewed from a specific point on the ground of East Asia. Thus, if a position measurement function compatible with CPS is installed in the quasi-zenith and stationary satellites, and these satellites are utilized together with the CPS, four satellites can be accessed simultaneously nearly all day long and a substantial improvement in position measurement, especially in metropolitan areas, can be achieved. The purpose of this paper is to evaluate the effectiveness of quasi-zenith satellite system on positioning accuracy improvement through simulation by using precise orbital information of the satellites and a three-dimensional digital map. Through this developed simulation system, it is possible to calculate the number of simultaneously visible satellites and available area for positioning without the need of actual observation. Furthermore, this system can calculate the Dilution Of Precision (DOP) and the error distribution.

• KIEAE Journal
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• 제15권4호
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• pp.13-20
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• 2015

Purpose: Pungsu is can be seen as an ecological architectural science regarding native natural environment of east asia. Even though the language used in Pungsu is different from that of ecological architecture, Pungsu considered the surrounding environment of the traditional house by various Pungsu method for making and keeping more healthy life and sustainable environment. The research is for finding out how the surrounding natural environment was considered with Pungsu, a traditional ecological architectural science in case of site selection and planning house by the confucian scholar in late Joseon period. Method: Sudan Nam-Gyu Lee's traditional house of Yesan in the middle of korea is selected. The study is processed as follows. The site was analyzed with feature and flow of mountains expressed as dragon in chapter 2 and four important hills around the house are analyzed in chapter 3. Finally Pungsu applied in architectural space is analyzed in chapter 4. Result: we can see that the traditional house of Sudang Lee Nam-Gyu has been planned considering Pungsu in details to minimize the negative factors and utilize the positive factors of nature as much as possible thinking nearby natural environment as environmental factors that can affect the residents of the house through Pungsu.

• 한국환경과학회지
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• 제1권2호
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• pp.15-23
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• 1992

Development of cumulus is studied by numerically integrating the equation of motion equations of conservation for water vapor mixing ratio, and the thermodynamic energy equuation. We use the terrain-following coordinate system called z'-coordinate system, in which we can easily treat any calculation domain with terrain configuration such as mountains. The model domain of calculation is restricted vertically to 4.Skin and horizontally to 100 km, has a bell-type mountain in the centeral part. Four cases are considered, one in a neutral environment, second in a slightly stable environment, third in a environment decreasing water content with low value of initial water vapor mixing ratio, the fourth in a case with higher vapor gradient. The more the atmosphere is unstable, the more cumulus develops easily and the more water vapors is abundant, the more cumulus develops easily too. More detailed cloud microphysics parameterizations and wet deposition must be conridered to use in air pollutants prediction model.

• 한국산림과학회지
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• 제98권2호
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• pp.189-196
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• 2009

This study was conducted to evaluate spatial distribution pattern and spatial association of crowns (${\geq}10m$ of height) and saplings (<10 m of height and ${\geq}2cm$ of DBH) for four major tree species (Pinus koraiensis, Abies nephrolepis, Acer mono, and Tilia amurensis) in the mixed broadleaved-Korean pine forest of Xiaoxing'an Mts. Vegetation data were collected in the 9 ha permanent sample plot, and the analysis adopted the point pattern analysis method. Main results are as follows; 1) crowns and saplings of major species showed clumped distribution pattern in small scale, became random distribution as the scale was increased. 2) Saplings of Pinus koraiensis performed poor regeneration under the crowns of Pinus koraiensis and Abies nephrolepis; Saplings of Abies nephrolepis did good regeneration under the crowns of Pinus koraiensis and Abies nephrolepis; and crowns of Acer mono and Tilia amurensis had little effect on the distribution of saplings of Pinus koraiensis and Abies nephrolepis. Saplings of Acer mono and Tilia amurensis made good regeneration under the crowns of Pinus koraiensis and Tilia amurensis; and the crowns of Acer mono and Abies nephrolepis had little effect on the distribution of saplings of Acer mono.

• Plant Resources
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• 제4권3호
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• pp.130-139
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• 2001

Four major naturally populated areas around the Jindong valley in Inje-Gun, Gangwon province for wild Pyrus ussuriensis, Malus sieboldii, and Malus baccata are mostly located on the southeast side of the mountains at 630-745m in altitude at sea level and are in very good sunny areas. The total of 77 taxa dividing into 32 families, 58 genera, 65 species, and 12 varieties has been inhabited in these areas. Most of these plants are heliophytes, which love sunshine, but some of rhizo-plants such as Sasa borealis, climbing plants such as Actinidia arguta and Celastrus orbiculatus, or naturalized plants like Bidens frondosa are also shown. These areas have been continually destroyed, so it is possibly thought that the second transition has been progressed. The index of species diversity of plant groups in these areas is 0.672∼1.465 based on the Shannon-Wiener's method, but its index for the area that rhizo-plants like Sasa borealis are growing as an under planting decreases relatively. In this study, the oldest plant of Pyrus ussuriensis in Korea, which is 120cm in diameter at breast height (DBH), 19m in tree height and 25m in width, has been found.

• Asian-Australasian Journal of Animal Sciences
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• 제13권8호
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• pp.1162-1172
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• 2000

The research was conducted to quantify farm and household characteristics of sheep farmers, evaluate farmer access to and the effectiveness of livestock services in sheep farming areas, and examine regional constraints to improving sheep productivity and profitability in Nepal. A rapid diagnostic socioeconomic survey of 200 sheep farmers was carried out in 1996 and all four ecological regions (Trans-Himalayan, Mountains, Hills and Terai), each with a distinct local sheep breed, were represented in the survey. Six major constraints were identified: (a) poor performance of local sheep breeds, (b) a serious seasonal deficit of pasture and other feed, (c) the lack of an organized market for wool and meat, (d) poor access to agricultural credit, (e) primitive shearing equipment, and (f) an inadequate supply of drinking water for sheep. Strategies to assist farmers develop their sheep management skills, improve access and quality of support services, improved technology adaptable to local conditions and effective linkages with local carpet and meat industry are likely to overcome the constraints and alleviate persistent poverty faced by sheep farmers in Nepal.

• 한국해양공학회지
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• 제27권2호
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• pp.80-86
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• 2013

KIOST developed a deep-sea mining robot called "MineRo" to collect manganese nodules in 2007. MineRo operates on flat ground. SMS (seafloor massive sulfide) deposits are shaped like undulating mountains. This paper deals with a numerical analysis model of a mining robot for SMS deposits. The mining robot consists of a tracked vehicle, chassis structure with a turntable, boom arm with 2 articulations, excavation tool, discharging unit, hydro-electric system, and sensing-and-monitoring system. In order to compare and analyze the dynamic responses of the driving mechanism, various tracked vehicles are modeled using commercial software. Straight driving simulations are conducted under undulating ground conditions. A conceptual design of a mining robot with four track systems for SMS deposits is modeled on the basis of these results.

• Geomechanics and Engineering
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• 제36권6호
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• pp.601-618
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• 2024

The joint probability distribution of uncertain geomechanical parameters of geotechnical strata is a crucial aspect in constructing the reliability functional function for roof structures. However, due to the limited number of on-site exploration and test data samples, it is challenging to conduct a scientifically reliable analysis of roof geotechnical strata. This study proposes a Copula method based on small sample exploration and test data to construct the intensity characteristics of roof geotechnical strata. Firstly, the theory of multidimensional copula is systematically introduced, especially the construction of four-dimensional Gaussian copula. Secondly, data from measurements of 176 groups of geomechanical parameters of roof geotechnical strata in 31 coal mines in China are collected. The goodness of fit and simulation error of the four-dimensional Gaussian Copula constructed using the Pearson method, Kendall method, and Spearman methods are analyzed. Finally, the fitting effects of positive and negative correlation coefficients under different copula functions are discussed respectively. The results demonstrate that the established multidimensional Gaussian Copula joint distribution model can scientifically represent the uncertainty of geomechanical parameters in roof geotechnical strata. It provides an important theoretical basis for the study of reliability functional functions for roof structures. Different construction methods for multidimensional Gaussian Copula yield varying simulation effects. The Kendall method exhibits the best fit in constructing correlations of geotechnical parameters. For the bivariate Copula fitting ability of uncertain parameters in roof geotechnical strata, when the correlation is strong, Gaussian Copula demonstrates the best fit, and other Copula functions also show remarkable fitting ability in the region of fixed correlation parameters. The research results can offer valuable reference for the stability analysis of roof geotechnical engineering.

• 한국환경과학회지
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• 제14권11호
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• pp.1015-1026
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• 2005

The southeastern coastal area of the Korean peninsula has a complex terrain including an irregular coastline and moderately high mountains. This implies that mesoscale circulations such as mountain-valley breeze and land-sea breeze can play an important role in wind field and ocean forcing. In this study, to improve the accuracy of complex coastal rind field(surface wind and sea surface wind), we carried out the sensitivity experiments based on PBL schemes in PSU/NCAR Mesoscale Model (MM5), which is being used in the operational system at Korea Meteorological Administration. Four widely used PBL parameterization schemes in sensitivity experiments were chosen: Medium-Range Forecast (MRF), High-resolution Blackadar, Eta, and Gayno-Seaman scheme. Thereafter, case(2004. 8. 26 - 8. 27) of weak-gradient flows was simulated, and the time series and the vertical profiles of the simulated wind speed and wind direction were compared with those of hourly surface observations (AWS, BUOY) and QuikSCAT data. In the simulated results, the strength of rind speed of all schemes was overestimated in complex coastal regions, while that of about four different schemes was underestimated in islands and over the sea. Sea surface wind using the Eta scheme showed the highest wind speed over the sea and its distribution was similar to the observational data. Horizontal distribution of the simulated wind direction was very similar to that of real observational data in case of all schemes. Simulated and observed vertical distribution of wind field was also similar under boundary layer(about 1 km), however the simulated wind speed was underestimated in upper layer.

• 건축역사연구
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• 제18권2호
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• pp.65-83
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• 2009

This research was to analyze the direction ideas of residential Feng Shui. In ancient China residential places were been established by Xiangzhai(相宅) and Buzhai(卜宅) usages. And ancient Chinese always considered geographical features of mountains and waters for setting up their living places. Geographical features were also considered importantly ih representative residential Feng Shui books, Zhaijing(宅經) and Yangzhaisanyao(陽宅三要). In Zhaihing, 24 direction ideas are co-related with Fagui(八卦) and GanZhi(千支) theories, and they are most important residential Feng Shiui direction theories. The basic thoughts of 24 direction ideas of Zhaijing were already formed in Qin(秦) dynasty and modified in early Han(漢) dynasty. In Zhaijing, residential places were splited into Yangzhai(陽宅) and Yinzhai(陰宅) according to YinYang's Qi directions. Those were actually formed from meticulous observations on changing processes of YinYangWuXing(陰陽五行)'s Qi(氣). Constantly changed Qi of YinYangWuXing were studied by old chinese people from the observations on the sun, the moon, the five stars, the Great Bear, and ErShiBaXiu(二十八宿). The origin of Zhaijing's direction ideas is the direction system of ShiPan(式盤) in Qin and Han dynasty. On ShiPan TianGan(天干) Dizi(地支) Fagui TianDiRenGui(天地人鬼) were arranged very systematically into four and 24 directions. DongxiSizhai(東西四宅) theories of Yangzhaisanyao had edited more lately than Zhaijing(宅經), and formed according to Fagui(八卦)'s YinYang(陰陽) principles. But the basic ideas is same with Zhaihing's. It proves that residential Feng Shui theories were constantly improved and modified. And both residential Feng Shui direction ideas of Zhaijing and Yangzhaisanyao are the gentral ideas in old china. The point of that ideas is Sky's four or 24 directions are correspndence with the earth's. It came from the traditional thoughts that Heaven, Earth, and mankind are c0-related and influenced each other according to Qi's changing processes. Gather up above mentioned, the direction ideas of residential Feng Shui is a systematic thoughts of old chinese for harmonizing Tian-Di-Ren-Gui, and is their specific methods for harmonizing the nature's Qi, mankind and spirits.