• Geosciences Journal
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• v.23 no.4
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• pp.547-556
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• 2019

A new species of the most primitive rosenellid stromatoporoid Cystostroma, C. primordia sp. nov. is reported from the Hunghuayuan Formation (Lower Ordovician, Floian) of Guizhou Province in the South China Block and the Duwibong Formation (Middle Ordovician, Darriwilian) of the Taebaeksan Basin in mid-eastern Korea (North China Block). This species is the first representative of the genus found in both the North and South China blocks. Cystostroma primordia sp. nov. is characterized by the absence of denticles and distinctively smaller cyst plates (height 0.04-0.20 mm, length 0.09-0.39 mm) than any other known species of Cystostroma. The presence of C. primordia sp. nov. in Lower to Middle Ordovician strata of western Gondwana challenges the long-held view of the late Middle Ordovician emergence of Paleozoic stromatoporoids. The simple internal morphological features of this new species and its occurrence in the Lower Ordovician of South China strongly indicate that an Early Ordovician Cystostroma-type precursor from western Gondwana is located near the base of the stromatoporoid stock. This occurrence greatly preceded the late Middle Ordovician (late Darriwilian) stromatoporoid diversification in circum-equatorial regions worldwide.

• Korean Journal of Remote Sensing
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• v.26 no.6
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• pp.617-627
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• 2010

Although many researches for heat island study have been developed, there is little attempt to link the findings to actual and hypothetical scenarios of urban developments which would help to mitigate the Urban Heat Island (UHI) in cities. The aim of this paper is to analyze the UHI at urban area with different geometries, land use, and environmental factors, and emphasis on the influence of different geometric and environmental parameters on ambient air temperature. In order to evaluate these effects, the parameters of (i) Air pollution (i.e. Aerosol Optical Thickness (AOT)), (ii) Green space Normalized Difference Vegetation Index (NDVI), (iii) Anthropogenic heat (AH) (iv) Building density (BD), (v) Building height (BH), and (vi) Air temperature (Ta) were mapped. The optimum operational scales between Heat Island Intensity (HII) and above parameters were evaluated by testing the strength of the correlations for every resolution. The best compromised scale for all parameters is 275m resolution. Thus, the measurements of these parameters contributing to heat island formation over the study areas of Hong Kong were established from mathematical relationships between them and in combination at 275m resolution. The mathematical models were then tabulated to show the impact of different percentages of parameters on HII. These tables are useful to predict the probable climatic implications of future planning decisions.

• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.2847-2858
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• 2021

When a nuclear reactor with rectangular fuel assemblies runs for a long time, impurities and debris may be taken into coolant channels, which may cause flow blockage, and the blocked fuel assemblies might be destroyed. Therefore, the purpose of this study is to perform a thermal-hydraulic analysis of a rectangular fuel assembly by STAR-CCM+, under the condition of one subchannel with 80% blockage ratio. A rectangular fuel assembly of the International Atomic Energy Agency (IAEA) 10 MW material test reactor (MTR) is chosen. In view of the gasket material taken into the coolant channel is close to the single side of the coolant channel, in the flow blockage accident of the Oak Ridge Research Reactor (ORRR), a new blockage category called single side blockage is attempted. The blockage positions include inlet, middle and outlet, and the blockage is set as a cuboid. It is found by simulations that the blockage redistributes the mass flow rate, and large vortices appear locally. The peak temperature of the cladding is maximum, when the blockage is located at the single side of the coolant channel inlet, and no boiling occurs in all blockage cases. Moreover, as the height of the blockage increases, the damage caused by the blockage increases slightly.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.50.2-50.2
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• 2019

Understanding three-dimensional structure and parameters (e.g., radial velocity, angular width, source location and density) of coronal mass ejections (CMEs) is essential for space weather forecast. In this study, we determine CME mean density in solar corona and near the Earth. We select 38 halo CMEs, which have the corresponding interplanetary CMEs (ICMEs), by SOHO/LASCO from 2000 to 2014. To estimate a CME volume, we assume that a CME structure is a full ice-cream cone which is a symmetrical circular cone combined with a hemisphere. We derive CME mean density as a function of radial height, which are approximately fitted to power-law functions. The average of power-law indexes is about 2.1 in the LASCO C3 field of view. We also obtain power-law functions for both CME mean density at 21 solar radii and ICME mean density at 1AU, with the average power-law index of 2.6. We estimate a ratio of CME density to background density based on the Leblanc et al.(1998) at 21 solar radii. Interestingly, the average of the ratios is 4.0, which is the same as a default value used in the WSA-ENLIL model.

• Journal of The Korean Astronomical Society
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• v.55 no.3
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• pp.67-74
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• 2022

In this study, we perform a statistical investigation of the kinematic classification of 4,264 coronal mass ejections (CMEs) from 1996 to 2015 observed by SOHO/LASCO C3. Using the constant acceleration model, we classify these CMEs into three groups: deceleration, constant velocity, and acceleration motion. For this, we devise three different classification methods using fractional speed variation, height contribution, and visual inspection. The main results of this study can be summarized as follows. First, the fractions of three groups depend on the method used. Second, about half of the events belong to the groups of acceleration and deceleration. Third, the fractions of three motion groups as a function of CME speed are consistent with one another. Fourth, the fraction of acceleration motion decreases as CME speed increases, while the fractions of other motions increase with speed. In addition, the acceleration motions are dominant in low speed CMEs whereas the constant velocity motions are dominant in high speed CMEs.

• Journal of Korean Port Research
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• v.6 no.1
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• pp.69-91
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• 1992

A new type of horizontal submerged break water or fixed structure to control waves near coastal area is introduced to focus wave energy before or behind it. Intentionally, the water depth near the structure is changed gradually to get a refraction and diffraction effect. The concentration of wave energy due to the structure was analyzed for the selected design of structure. The shape of the submerged structure in consideration is a circular combined with elliptical curve not to cause reflection of waves at the extreme edge of the structure but cause wave scattering. The direction of the structure against the incident wave is changed easily in the model Applying a regular wave train the following were examined. 1) whether a crescent plain submerged structure designed by the wave refraction theory can concentrate wave energy at a focal zone behind and before it without wave breaking phenomenon. 2) Location of maximum wave amplification factor in terms of the incident wave direction, wave period, etc. In any event the study would contribute to control waves near coastal area and to protect a beach from erosion without interruption of ocean view it is an useful study for the concentration of wave energy efficiently with the increase of wave height.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.2
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• pp.30-37
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• 2018

The uniformed regulations for control of the height of buildings owned by individuals to protect landscape of cultural properties are causing serious social conflicts by limiting the development of landowners. It is urgent need of introducing indicators that can resolve such conflicts and evaluate the regulations of buildings, which can satisfy urban development as well as landscape management of cultural properties. Therefore, the purpose of this study is to simulate landscape changes according to the Cultural Heritage Protection Act and National Land Planning and Utilization Act by using Unity3D in the Pungnammun Gate(Treasure No. 308) of Jeonju and its surroundings, where architectural cultural property forms the symbolic landscape of the city. Then some items such as view points, target points were introduced and the quantitative evaluation of landscapes was attempted by applying the indicator of 3D Visual Exposure. As a result, the viewing opportunity and viewing area of Pungnammun Gate were not significantly influenced by changes in landscape according to the two laws. However, the change of the height of buildings by the National Land Planning and Utilization Act, which has the greatest development capacity, confirmed the possibility of weakening the identification of the Pungnammun Gate by increasing 3D Visual Exposure of the background buildings more than two times. Finally, it was confirmed that the skyline of Pungnammun Gate was clearly infringed upon development under the National Land Planning and Utilization Act, but the skyline was maintained similar to the current situation in the regulation by the Cultural Heritage Protection Act. Thus, this study is meaningful in that the application of 3D Visual Exposure showed the possibility of utilization as an indicator for quantitatively evaluating the protection of view on cultural property and skyline according to the changes of building heights.

• Journal of the Korean Society of Food Science and Nutrition
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• v.5 no.1
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• pp.39-51
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• 1976

We arrive at the conclusion as follows as for the connection between dietary life, hours of exercise and growth of body, based on the survey of their height, this circumference of the breast and their body weight, and the questionnaires to the pupils of 36,547 in totals (contained the primary and middle school boys and girls) in four districts(named A, B, C and D district) of Jeonlla Bug Do from April, 1970 to March, 1973. (1) The growth in height. The boys from 6 to 7 years old are nearly same in all districts, but as age increases, those of A district grow more rapidly than those of B, C and D districts, while those of B, C and D districts grow almost samely. The girls already from 6 years old on are different between A district and B, C, D district. The average of height in Jeonlla Bug Do is not different from that of Gyungi Do and whole nation in the pupils from 6 to 11 years old, and that of Japan from 6 to 7 of age, while it falls behind them as age increases. (2) The growth in the circumference of the breast. The boys from 6 to 9 years old show nearly the same tendency in all districts, after that age the boys in A district tend to grow rapidly, those in B district most fall behind, and those in C, D districts show the same tendency. Contrasted with height the growth in the circumference of the breast does not show the difference in each district so far as 14 of age, but after 15 years old it shows a little difference by falling behind of pupils in A district, while those B, C, D districts show almost the same tendency. The average of the circumference of the breast in Jeonlla Bug Do of the pupils from 10 to 11 of age is almost same to that of Gyungi Do, whole nation and Japan, but shows difference after that age. (3) The growth of body weight. The body weight of boys over-all the investigated whole age shows the superiority in A district and a little lowness in D district which is almost same to that of B, C districts. In that of girls, A district is superior in from 6 to 9 of age, and all districts are nearly same after that age. The average in Jeonlla Bug Do is one and the same to those of Gyungi Do, whole nation and Japan as in the height, but shows the great difference as years grow. (4) The dietary life of the pupils in Jeonlla Bug Do depends chiefly upon a carbohydrate and is very low in the intake of fat and protein. Connected with a view point of districts, the intake of protein is a little more in A district than in the other districts, and is nearly same in the other districts. They tend more to eat mixed food, but about 40% of them do not yet eat it. The contents and taking of lunch is bad in the highest degree, to which their parents are entirely indifferent. As far as the hours of exercise are concerned with, about 40% of all pupils must go to the school from very far, which gives them the heavy physical suffering, and especially it is remarked that the middle school boys and girls should attend school from farther than the primary school boys and girls.

• Clinical and Experimental Pediatrics
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• v.50 no.7
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• pp.678-685
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• 2007

Purpose : Recent reports pointed out that gonadotropin releasing hormone analogue (GnRHa) therapy alone is not so promising for improving adult height in precocious puberty. So, that we studied the growth promoting effect of combined therapy with GnRHa and growth hormone (GH) in early pubertal girls. Methods : Twenty three early pubertal girls ($9.73{\pm}1.59yr$) with predicted adult heights (PAH) below-2 standard deviation score (SDS) were included. They were divided into two groups as follows; Group I before menarche (n=19) and Group II after menarche (n=4). After combined therapy, various growth parameters were compared between two groups and between the before and after therapy. Results : Between the two groups before therapy, chronologic age (CA), growth velocity (GV), body mass index (BMI), target height (TH), PAH and serum insulin-like growth factor binding protein-3 were not different, but BA, height and difference between bone age (BA) and CA were significantly higher and insulin-like growth factor-1 (IGF-1) was marginally higher in group II. After therapy, BA still remained higher in group II, but other parameters were not different. In both groups, after therapy, the difference between BA and CA, the ratio of BA over CA, and GV were significantly decreased, but PAH, height SDS and BMI were significantly increased. Regarding IGF-1 level, a significant increase was noted in group I, but not in group II. Conclusion : With combined therapy of GnRHa and GH, PAH in early pubertal girls might be improved significantly and even approach TH. Among them, those who were before menarche might have greater potential for the height gain than those after menarche in view of IGF-1 changes during therapy.

• Computational Structural Engineering
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• v.6 no.3
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• pp.67-80
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• 1993

This paper presents the results of an analytical study to evaluate the inelastic seismic response characteristics of multistory building structures, the effects of gravity load on the seismic responses and its implications on the earthquake resistant design. Static analyses for incremental lateral force and nonlinear dynamic analyses for earthquake motions were performed to evaluate the seismic response of example multistory building structures. Most of considerations are placed on the distribution of inelastic responses over the height of the structure. When an earthquake occurs, bending moment demand is increased considerably from the top to the bottom of multistory structures, so that differences between bending moment demands and supplies are greater in lower floos of multistory structures. As a result, for building structures designed by the current earthquake resistant design procedure, inelastic deformations for earthquake ground motions do not distribute uniformly over the height of structures and those are induced mainly in bottom floors. In addition, gravity load considerded in design procedure tends to cause much larger damages in lower floors. From the point of view of seismic responses, gravity load affects the initial yield time of griders in earlier stage of strong earthquakes and results in different inelastic responses among the plastic hinges that form in the girders of a same floor. However, gravity load moments at beam ends are gradually reduced and finally fully relaxed after a structure experiences some inelastic excursions as a ground motion is getting stronger. Reduction of gravity load moment results in much increased structural damages in lower floors building structures. The implications of the effects of gravity load for seismic design of multistory building structures are to reduce the contributions of gravity load and to increased those of seismic load in determination of flexual strength for girders and columns.