• Economic and Environmental Geology
• /
• v.45 no.1
• /
• pp.9-21
• /
• 2012

In this study, we investigated the chemical characteristics of soils collected from the several deserts and loess in China known as the typical source areas of Asian dust (the Taklamakan desert, the Alashan desert, the Ordos desert and the Loess Plateau). Based on our analysis, we examined the possibility of adverse effects on environments and human health. In each desert and loess, major elemental compositions of soils did not show large variations, implying that the long-periodic mixing of soils in each area made their chemical compositions homogeneous. Minor elements of soils in each desert and loess showed more complicated patterns with strong correlations each other (e.g., Cr, Cu, As, Co, Ni, V, Y, Sc, Sn, Pb, Zn, Cd, Cs, Li, Th, U). These results thus enable us to discriminate the soil of the Loess Plateau from those of the other deserts in China. The results of sequential extraction experiments for soils showed that the chemical speciation of Fe was dominant in residual fraction (>85%) in all deserts and loess, but the fractions of Mn and Ca chemical speciations were very different in each area. In the case of Mn, the fraction of amorphous Fe-Mn hydroxides (55.4%) in the Central Loess Plateau and the carbonate fraction (33.8%) in Taklamakan desert were higher as much as 2 to 5 times than other deserts. The chemical speciations of Ca are dominant in carbonate fraction in Taklamakan (75.9%) and Alashan (50.5%) deserts, but carbonate fractions of Ca in the Loess Plateau and Ordos deserts were low (6.6% and 2.1%, respectively). According to the mobility of trace elements inferred from the results of sequential extraction procedure, we could classify them into five groups, and the mobility of Cd, Pb and Cu are more than 87%, 33% and 30%, respectively. Therefore, Cd, Pb and Cu in soils of deserts and loess could be easily dissolved when interacted with surface water. As such, they could give adverse effects on surficial environments and human health.

• Journal of Elementary Mathematics Education in Korea
• /
• v.11 no.2
• /
• pp.177-197
• /
• 2007

This study discussed the climbing learning method which studied and practiced by Professor Saito Noboru. This is the learning method which is devised to know not only the relationship of the learning factors but the systemic or structural connection of whole studying contents- affects children's math learning ability through practical class to both the lower and the higher grades. To achieve the purpose of this study, these following issues were set; A. Develop the teaching and learning course of mathematics by applying the climbing learning method. B. Execute the mathematics lesson according to the climbing learning method and analyze the learning achievement. C. Analyze the difference between application of the climbing learning method and that of the learning method by student's level in mathematics. D. Analyze what the climbing learning method gives a shift of the recognition of learning mathematics. In order to accomplish these study issues, we analyzed the text book of math not only for children but also for teachers and developed the teaching and learning course applied the climbing learning method with advice of experts. It was chosen two different homogeneous groups each, third year for lower grade group and fifth year for higher grade group. It was done the experimental group lesson applying the climbing learning method and general lesson for the control group. After then, t-test against independent samples was done depending on the result of the student's assessment(T1, T2). These two groups' students were divided into smaller groups based on result of achievement level regardless of gender. These subgroups were confirmed the difference of learning ability between upper and lower level group. As regarding the result making out grades of faith and attitude for math, t-test was used on independent sample. At the same time, experimental groups were tested using learning attitude with the learning structure chart. Through this study the following results are obtained and the conclusion was drawn. Firstly, although applying the climbing learning method to the lesson does not have significant effect to the lower grade of elementary school student's achievement it has significant influence on the higher grade student's achievement. Second, as a result of analyzing the difference between the climbing learning method and the learning method by student's level in mathematics, it is of no beneficial effect to the lower grade both upper level and lower level. However, it has appreciable effect to the higher grade classes both upper level and low level. Especially, upper level students have higher effect than low level students. Third, climbing learning method does not affect to the faith and attitude of the lower grade students positively, but it has affirmative effect to the higher grade students'. As a result of the survey of the experimental groups which were applied to the climbing loaming method, the lesson by using the learning structure chart proved to be helpful to the both the lower and higher grade. The best advantage of using the learning structure chart, children say, is easily understood whole contents of studying and is useful for review. Furthermore, using the learning structure chart is more efficient compared with previous learning method and is given the successful result to self-directed learning. In conclusion, keeping up with the current of the thought of education, we suggest a scheme as a new teaching method from the constructive learning method which emphasize the self-directed learning.

• Journal of Korean Society for Geospatial Information Science
• /
• v.24 no.1
• /
• pp.109-119
• /
• 2016

The height datum of Korea is currently separated into land and sea, which makes it difficult to acquire homogeneous and accurate height information throughout the whole nation. In this study, we therefore tried to suggest the more effective way to transform the height information were constructed separately according to each height datum on land and sea to those on the unique height datum using precise geoid models and tidal observations in Korea. For this, Anmyeon island was selected as a study area to develop the precise geoid models based on the height datums land (IMSL) and sea (LMSL), respectively. In order to develop two hybrid geoid models based on each height datum of land an sea, we firstly develop a precise gravimetric geoid model using the remove and restore (R-R) technique with all available gravity observations. The gravimetric geoid model were then fitted to the geometric geoidal heights, each of which is represented as height datum of land or sea respectively, obtained from GPS/Leveling results on 15 TBMs in the study area. Finally, we determined the differences between the two hybrid geoid models to apply the height transformation between IMSL and LMSL. The co-tidal chart model of TideBed system developed by Korea Hydrographic and Oceanographic Agency (KHOA) which was re-gridded to have the same grid size and coverage as the geoid model, in order that this can be used for the height datum transformation from LMSL to local AHHW and/or from LMSL to local DL. The accuracy of height datum transformation based on the strategy suggested in this study was approximately ${\pm}3cm$. It is expected that the results of this study can help minimize not only the confusions on the use of geo-spatial information due to the disagreement caused by different height datum, land and sea, in Korea, but also the economic and time losses in the execution of coastal development and disaster prevention projects in the future.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.4 no.3
• /
• pp.255-263
• /
• 2006

Vol-oxidizer is a device to convert $UO_2$ pellets into $U_3O_8$ powder and to feed a homogeneous powder into a Metal Conversion Reactor in the ACP(Advanced Spent Fuel Conditioning Process). In this paper, we propose a design model of the vol-oxidizer, develop the new vol-oxidizer with a capacity of 20 kg HM/batch in $UO_2$ pellets, and conduct a verification for the device. Design considerations include the internal structure, the capacity, the heating position of the device, and the size. The dimensions of the new vol-oxidizer are decided by the design model. We determine a permeability test of the $U_3O_8$ measuring the temperature distribution, and the volume of $UO_2$ and $U_3O_8$. We manufactured the new vol-oxidizer for a 20 kg HM/batch in $UO_2$ pellets, and then analyzed the characteristics of the $U_3O_8$ powder for the verification. The experimental results show that the permeability of the $U_3O_8$ throughout mesh enhance more than old vol-oxidizer, the oxidation time takes only 8 hours when compared with the 13 hours of the old device, and the average distribution of particle size is $40{\mu}m$. The capacities of new vol-oxidizer for a 20 kg HM/batch in $UO_2$ pellets were agree well with the predictions of design model.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.10 no.3
• /
• pp.189-197
• /
• 2012

Geochemical composition of fracture filling minerals and groundwater was investigated to characterize geochemical characteristics of groundwater system at the KURT site. Minerals such as calcite, illite, laumontite, chlorite, epidote, montmorillonite, and kaolinite, as well as I/S mixed layer minerals were detected in the minerals extracted from the fracture surfaces of the core samples. The groundwater from the DB-1, YS-1 and YS-4 boreholes showed alkaline conditions with pH of higher than 8. The electrical conductivity (EC) values of the groundwater samples were around $200{\mu}S/cm$, except for the YS-1 borehole. Dissolved oxygen was almost zero in the DB-1 borehole indicating highly reduced conditions. The Cl- concentration was estimated around 5 mg/L and showed homogeneous distribution along depths at the KURT site. It might indicate the mixing between shallow groundwater and deep groundwater. The shallow groundwater from boreholes showed $Ca-HCO_3$ type, whereas deep groundwater below 300 m from the surface indicated $Na-HCO_3$ type. The isotopic values observed in the groundwater ranged from -10.4 to -8.2‰ for ${\delta}^{18}O$ and from -71.3 to -55.0‰for ${\delta}D$. In addition, the isotope-depleted water contained higher fluoride concentration. The oxygen and hydrogen isotopic values of deep groundwater were more depleted compared to the shallow groundwater. The results from age dating analysis using $^{14}C$ indicated relatively younger (2000~6000yr old) groundwater compared to other european granitic groundwaters such as Stripa (Sweden).

• The Korean Journal of Pharmacology
• /
• v.22 no.1 s.38
• /
• pp.60-70
• /
• 1986

Distributions of serum dopamine-${\beta}$-hydroxylase(DBH) activity and thermostability in a randomly selected population of Korean adults were studied to investigate the genetic factor which could exert an influence on the serum DBH activity and thermostability. The results were followings: 1. The mean serum DBH activity in a randomly selected population of adults was $18.3{\pm}4.5$ umol/min/l($mean{\pm}SD;n=327$) which showed no age or sex variation. 2. The frequency distribution showed no isolated subgroup with very low serum DBH activity. 3. When the ratio of enzyme activity after heating $55^{\circ}C$ for 20 minutes to that before heating (heated-to-control or H/C ratio). was used as a measure of thermostability, the mean serum DBH H/C ratio in a randomly selecfld population, of adults was $0.90{\pm}0.17(mean{\pm}SD; n=327)$ which showed no age or sex variation. 4. Serum DBH H/C ratio showed unimodal, homogeneous distribution. 5. There was significant negative correlation between serum DBH activity and H/C ratio(r=-0.39. p<0.01). 6. Subjects with H/C ratio less than 0.1 had significantly higher basal enzyme activity $(22.2{\pm}4.5)$ $(mean{\pm}SD;n=33)$ umo1/min/1 than those with H/C ratio more than 1.09 $(15.5{\pm}3.3)$ $(mean{\pm}SD;n=32)$ umo1/min/1. This study shows that the distribution patterns of serum DBH activity and thermostability of Korean population are considerably different from those of Caucasian and it might be a line of evidence for the different inheritance pattern of plasma DBH enzyme between these racial groups.

• The Journal of Korean Society for Radiation Therapy
• /
• v.25 no.1
• /
• pp.15-24
• /
• 2013

Purpose: In Asan Medical Center, Two parallel opposite beams are employed for total body irradiation. Patients are required to be in supine position where two arms are attached to mid axillary line. Normally, physical compensators are required to compensate the large dose difference for different parts of body due to the different thicknesses compared to the umbilicus separation. There was the maximum dose difference up to 30% in lung and chest wall compared to the prescription dose. In order to resolve the dose discrepancy occurring on different body regions, the feasibility of using Fieid-in-Field Technique is investigated in this study. Materials and Methods: CT scan was performed to The RANDO Phantom with fabricated two arms and sent to Eclipse treatment planning system (version 10.0, Varian, USA). Conventional plan with physical lead compensator and new plan using Field-in-Field Technique were established on TPS. AAA (Anisotropic Analytical Algorithm) dose calculation algorithm was employed for two parallel opposite beams attenuation. Results: The dose difference between two methods was compared with the prescription dose. The dose distribution of chest and anterior chest wall uncovered by patient arms was 114~124% for physical lead compensator while Field-in-Field Technique gave 106~107% of the dose distribution. In-vivo dosimetry result using TLD showed that the dose distribution to the same region was 110~117% for conventional physical compensator and 104~107% for Field-in-Field Technique. Conclusion: In this study, the feasibility of using FIF technique has been investigated with fabricated arms attached Rando phantom. The dose difference was up to 17% due to the attached arms. It is shown that the dose homogeneity is within ${\pm}10%$ with the CT based 3-dimensional 4 step FIF technique. The in-vivo dosimetry result using TLD was showed that 95~107% dose distribution compared to prescription dose. It is considered that CT based 3-dimensional Field-in-Field Technique for the total body irradiation gives much homogeneous dose distribution for different body parts than the conventional physical compensator method and might be useful to evaluate the dose on each part of patient body.

• Korean Journal of Cognitive Science
• /
• v.25 no.3
• /
• pp.211-232
• /
• 2014

People search a certain object or a person so many time in a day. Besides the information about what the target is, perceptual information of the target can influence on the search process. In the current study, using an eye-tracker we aimed to examine whether the perceptual information of previewing target stimuli on the visual search process of the target and the task performance. Participants had to identify the previewing target stimulus presented in the middle of the screen, and then had to search the target among 8 items presented in a circle array, and had to decide whether the size of the target in the search display was same as that of the previewing stimulus. The experimental conditions were divided into 8 within-subject conditions by whether the search display was consisted of all the same size items or different size items (homogeneous search display vs. inhomogeneous search display), by the size of the preview target stimulus, and by the size of the target stimulus in the search display. Research hypothesis is that the size information of the previewing influence on the visual search process of the target and task performance when the items in the search display are in different sizes. In the results of behavioral data analysis, the reaction time showed the main effect of the search display, and the size of the target stimulus in the search display. and the interaction between the size consistency effect of target stimulus and the search display condition. In the results of analysis of eye-movement information, the Initial Saccade to Target Ratio measurement showed the interaction between the size consistency effect of target stimulus and the search display condition as the reaction time measurement did. That is, the size consistency effect of target stimulus only in the inhomogeneous search display condition indicated that participants searched the items in the same size as that of preview target stimulus. Post-hoc analyses revealed that the search and task performance in the inhomogeneous display condition were faster when the target size was consistent, but rather slower when the target size was inconsistent.

• Journal of Soil and Groundwater Environment
• /
• v.13 no.4
• /
• pp.8-21
• /
• 2008

A series of three-dimensional numerical simulations using a hydrodynamic dispersion numerical model is performed to analyze quantitatively impacts of layered heterogeneity of geologic media and groundwater pumping schemes on groundwater flow and salt transport in coastal aquifer systems. A two-layer heterogeneous coastal aquifer system composed of a lower sand layer (aquifer) and an upper clay layer (aquitard) and a corresponding single-layer homogeneous coastal aquifer system composed of an equivalent lumped material are simulated to evaluate impacts of layered heterogeneity on seawater intrusion. In addition, a continuous groundwater pumping scheme and two different periodical groundwater pumping schemes, which withdraw the same amount of groundwater during the total simulation time, are applied to the above two coastal aquifer systems to evaluate impacts of groundwater pumping schemes on seawater intrusion. The results of the numerical simulations show that the periodical groundwater pumping schemes have more significant adverse influences on groundwater flow and salt transport not only in the lower sand layer but also in the upper clay layer, and groundwater salinization becomes more intensified spatially and temporally as the pumping intensity is higher under the periodical groundwater pumping schemes. These imply that the continuous groundwater pumping scheme may be more suitable to minimize groundwater salinization due to seawater intrusion. The results of the numerical simulations also show that groundwater salinization in the upper clay layer occurs significantly different from that in the lower sand layer under the periodical groundwater pumping schemes. Such differences in groundwater salinization between the two adjacent layers may result from layered heterogeneity of the layered coastal aquifer system.

• Journal of Sericultural and Entomological Science
• /
• v.15 no.2
• /
• pp.15-20
• /
• 1973

This will be second publication regard with silkworm selection using anesthetic followed by previous report. This treatise investigated for nacorsis recovery concerned with silkworm health through more directions than the previous paper. After the author has found a possibility of silkworm seperation through nacorsis recovery, he has recommended to use Balance Health (BH) value system to evaluate or identify silkworm health and to produce better homogeneous silkworm eggs. Also, the author has continued the observation for the next generation how once nacortized parents affect to their family. The obtained results are summarized as followings. 1. Basic investigation a) Hybrid silkworm variety recovers from nacorsis earlyer than pure line because it is stronger. b) Strong pure line variety recovers from nacorsis earlyer than weak one because it is stronger. c) Male worm recovers from nacorsis earlyer than female worm because it is stronger. 2. Establishment of Balance Health(BH) value system. In order to identify each seperated group by nacorsis and their family, the following Balance Health (BH) value indicating system was established.(Table Omitted) 3. In order to select better silkworm during breeding service, the BH value indicating system is strongly recommended. That is, in case BH value is smaller than four, it would be strong group or in case BH value is larger than four, it would be weak group. 4. Once nacortized parents do not harm any nature for next generation regardless P$_1$ or F$_1$ production. 5. The seperation through nacorsis may delay retrograde phenomenon some years than other case, so, this system should be used for pure line production every year. 6. It is recommended to nacortize silkworm for five minutes on breeding purpose, but two and half minutes on pure lines reproduction at fifth instar. 7. This report has been discussed in relation to practical industry promotion aspects, but there are many subjects to be solved from academical aspect in future