• Journal of Radiation Protection and Research
• /
• v.41 no.1
• /
• pp.31-39
• /
• 2016

Background: It is necessary to consider the overall countermeasure for analysis of nuclear activities according to the increase of the nuclear facilities like nuclear power and reprocessing plants in the neighboring countries including China, Taiwan, North Korea, Japan and South Korea. South Korea and comprehensive nuclear-test-ban treaty organization (CTBTO) are now operating the monitoring instruments to detect radionuclides released into the air. It is important to estimate the origin of radionuclides measured using the detection technology as well as the monitoring analysis in aspects of investigation and security of the nuclear activities in neighboring countries. Materials and methods: A three-dimensional forward/backward trajectory model has been developed to estimate the origin of radionuclides for a covert nuclear activity. The developed trajectory model was composed of forward and backward modules to track the particle positions using finite difference method. Results and discussion: A three-dimensional trajectory model was validated using the measured data at Chernobyl accident. The calculated results showed a good agreement by using the high concentration measurements and the locations where was near a release point. The three-dimensional trajectory model had some uncertainty according to the release time, release height and time interval of the trajectory at each release points. An atmospheric dispersion model called long-range accident dose assessment system (LADAS), based on the fields of regards (FOR) technique, was applied to reduce the uncertainties of the trajectory model and to improve the detective technology for estimating the radioisotopes emission area. Conclusion: The detective technology developed in this study can evaluate in release area and origin for covert nuclear activities based on measured radioisotopes at monitoring stations, and it might play critical tool to improve the ability of the nuclear safety field.

• Analytical Science and Technology
• /
• v.20 no.5
• /
• pp.383-392
• /
• 2007

The water soluble components were analyzed in the $PM_{2.5}$ fine particles collected at the 1100 site of Mt. Halla for the spring seasons between 1998 and 2004. The $PM_{2.5}$ mass concentrations were within $13.4{\pm}9.6{\sim}21.7{\pm}20.0{\mu}g/m^3$, and the concentrations of ionic components were in the order of nss-$SO{_4}^{2-}$ > $NH{_4}{^+}$ > $NO{_3}{^-}$ > $Ca^{2+}$ > $K^+$ > $Na^+$ > $Cl^-$ > $Mg^{2+}$, in which the concentration of nss-$SO{_4}^{2-}$($3.41{\pm}2.42{\mu}g/m^3$) was the highest. The concentrations of $NH{_4}{^+}$, $SO{_4}^{2-}$, and $NO{_3}{^-}$, the secondary pollutants, were respectively 0.60~1.50, 2.86~4.42, and $0.24{\sim}1.57{\mu}g/m^3$, which had occupied 88 % of the total ionic components, on the other hand, the concentrations of marine species were less than 5 %. The nss-$SO{_4}^{2-}$ showed the high correlation with $NH{_4}{^+}$, $K^+$, so that $NH{_4}{^+}$ and nss-$SO{_4}^{2-}$ might exist in the form of $(NH_4)_3H(SO_4)_2$ and $(NH_4)_2SO_4$ in fine particles. From the backward trajectory analysis, in case of high concentrations of $NH{_4}{^+}$ and nss-$SO{_4}^{2-}$ simultaneously, the air masses were originated and stagnated at the east region of China for a while, then moved into the atmosphere of Jeju. However, in case of $NO{_3}{^-}$ and nss-$Ca^{2+}$, the air masses originated at China and Siberia were moved into Jeju via the eastern China.

• The korean journal of orthodontics
• /
• v.42 no.6
• /
• pp.280-290
• /
• 2012

Objective: This study aimed to compare the effects of conventional and orthodontic mini-implant (OMI) anchorage on tooth movement and arch-dimension changes in the maxillary dentition in Class II division 1 (CII div.1) patients. Methods: CII div.1 patients treated with extraction of the maxillary first and mandibular second premolars and sliding mechanics were allotted to conventional anchorage group (CA, n = 12) or OMI anchorage group (OA, n = 12). Pre- and post-treatment three-dimensional virtual maxillary models were superimposed using the best-fit method. Linear, angular, and arch-dimension variables were measured with software program. Mann-Whitney U-test and Wilcoxon signed-rank test were performed for statistical analysis. Results: Compared to the CA group, the OMI group showed more backward movement of the maxillary central and lateral incisors and canine (MXCI, MXLI, MXC, respectively; 1.6 mm, p < 0.001; 0.9 mm, p < 0.05; 1.2 mm, p < 0.001); more intrusion of the MXCI and MXC (1.3 mm, 0.5 mm, all p < 0.01); less forward movement of the maxillary second premolar, first, and second molars (MXP2, MXM1, MXM2, respectively; all 1.0 mm, all p < 0.05); less contraction of the MXP2 and MXM1 (0.7 mm, p < 0.05; 0.9 mm, p < 0.001); less mesial-in rotation of the MXM1 and MXM2 ($2.6^{\circ}$, $2.5^{\circ}$, all p < 0.05); and less decrease of the inter-MXP2, MXM1, and MXM2 widths (1.8 mm, 1.5 mm, 2.0 mm, all p < 0.05). Conclusions: In treatment of CII div.1 malocclusion, OA provided better anchorage and less arch-dimension change in the maxillary posterior teeth than CA during en-masse retraction of the maxillary anterior teeth.

• Korean Journal of Construction Engineering and Management
• /
• v.16 no.4
• /
• pp.12-20
• /
• 2015

Construction industry has played a pivotal role in the national economy, but the crisis situation of a construction industry has been worse due to the lack of recognition of the contribution of a construction industry. In particular, the transport sector is responsible for a critical function in the movement of humans and material resources, and has a profound impact on national competitiveness and the peoples' welfare, which requires quantitative analysis. In this study, economic contribution and impact of the transportation sector are measured based on the input-output model. Road and railway facilities account for 1.03% and 0.165% of the total industry respectively, and consist of a final demand and total output. Although value-added inducing effect is small, production inducing effect and backward linkage effect has been high. The results in this study will be used as the basic information for validity of investment and policy decisions.

• The Journal of the Korea Contents Association
• /
• v.11 no.1
• /
• pp.317-328
• /
• 2011

Logistic system and methods of the transportation have been changed rapidly by the variety of the logistics environment. It is necessary to analyze the efficiency of Korean trucking companies for enhancing the competitive power and operating. This paper will describe the analysis of the efficiency of the trucking companies with DEA models. By the CCR and the BCC models, which are in parts of DEA model, the efficiency and RTS(Return To Scale) of forty two selected trucking companies were studied. It was also analyzed how the study the input-output variables were effected. And then, some of the forty two trucking companies were shown as the benchmark. As the result of analysis on the two models, seven companies won the score '1' on CCR model and seventeen companies on BCC model. Moreover, this study showed that reducing the total asset out of input variables, and raising the sales profit out of the output variables played a main role to increase the efficiency of the trucking companies highly.

• Journal of the Korean Society of Tobacco Science
• /
• v.21 no.2
• /
• pp.109-118
• /
• 1999

A model predicted describing the effect of cigarette making materials on the level of filter ventilation was developed and evaluated. The developed model was expressed in terms of a linear and quadratic relationship which was validated with experimental measurements for different porosity of plug wrap and tipping paper, unencapsulated pressure drop of filter plug and cigarette column and vent position. Forty-six experimental frequencies were determined as a result of using three levels with five factors Box-Behnken design and analyzed by the multiple regression analysis with backward stepwise in STATISTICA/PC under restricted conditions. The four factors, except filter pressure drop variable, were statistically significant at the level of 0.05 but most of all linear by linear interactions were comparatively lower significant. By the analysis of linear and quadratic regression coefficient, filter ventilation of the cigarette was affected by porosity of plugwrap (5.87, -4.25), porosity of tip paper (5.68, -1.00), vent position (-3.87, 3.08), tobacco column pressure drop (2.56, 0.66), and filter pressure drop (1.50, 0.58) in the decreasing order. It should be emphasized that the major conclusion of this study was not that any particular parameter was linear or quadratic on any limit scale, but that there were highly significant relationships among factors involving linear, quadratic and their interaction and perhaps even linearity between and within factors. While, there is also quite strong evidence that vent position from mouth end and cigarette making materials are reverse relationship on this experimental model. On the basis of the result, it can be concluded that the porosity of the plug wrap and tipping paper has a marked effect on degree of filter ventilation rate. The F-value of plug wrap and tipping paper porosity among five factors were 39.2 and 36.8 respectively with P-value of 0.000 indicating higher significant for both factors. According to the analysis of variance, the model fitted for filter ventilation was significant at 5% confidence level and the coefficient of determination ($R^2$=0.84) was the proportion to variability in the data well fitted for by the model.

• Knowledge Management Research
• /
• v.17 no.1
• /
• pp.73-89
• /
• 2016

The digital culture contents is one of the fastest growing industry in Korea and it accounts for 60% of the digital contents industry. This paper attempts to analyze economic impacts of the digital culture contents industry using input-output analysis. This study investigated the production-inducing effect, value-added-inducing effect and employment-inducing effect of the digital culture contents industry based on a demand-driven model. In addition, the study dealt with the supply shortage effect and sectoral price effect of the digital culture contents industry using a supply-driven model and the Leontief price model, including the inter-industry linkage effects of 29 sectors with the digital culture contents industry sector. Some interesting findings were drawn from the study. First, production of 1.0 won in the digital culture contents industry results in production-inducing effect of 2.39542 won, value-added effect of 1.29895 won and employment-inducing effect of 0.39657 persons in other industries. Second, the supply shortage of 1.0 won in the digital culture contents industry prevents other industries from producing 0.56631 won. Third, a 1% increase in the price level of the digital culture contents industry raises the overall price level by 0.06017%. Finally, very high backward linkage effects were found, but forward linkage effects were minimal.

• Phonetics and Speech Sciences
• /
• v.12 no.1
• /
• pp.51-63
• /
• 2020

Phonological awareness is a metalinguistic awareness ability of phonology and is known to predict language skills, such as reading and vocabulary skills. The purpose of this study was to investigate the relationship between phonological awareness, phonological processing, and language skills in 4- to 6-years-old typically developing (TD) children and children with language delay (LD). A total of 32 children (TD=18, LD=15) participated in this study. They performed a phonological awareness task consisting of counting, deletion, and discrimination at syllable level. Nonword Repetition, Digit Backward, Receptive & Expressive Vocabulary Test, and Grammaticality Judgment Task were performed to analyze the correlation between phonological awareness, phonological processing, and language ability. A multiple stepwise regression analysis was performed to examine the phonological awareness subtasks that predict language ability. In the TD group, the syllable categorization task significantly predicted the receptive vocabulary and the performance of the Grammaticality Judgment Task. The LD group showed that the syllable counting task significantly predicted the receptive vocabulary, the expressive vocabulary, and the performance of the Grammaticality Judgment Task. The results showed that the phonological awareness performance was significantly different between the two groups. Further, correlation analysis and regression analysis showed different results for each group. The result of the phonological awareness performance predicted the language ability of each group significantly, suggesting the importance of the meta-linguistic awareness ability of phonology.

• Korean Journal of Applied Biomechanics
• /
• v.16 no.2
• /
• pp.97-108
• /
• 2006

C. H. OH, S. N. CHOI, T. G. NAM, The Kinematic Analysis of the Tennis Flat Serve Motion, Korean Jiurnal of Sports Biomechanics, Vol. 16, No. 2, pp. 97-108, 2006. By the comparison and the analysis of the different factors during the tennis flat serve motion such as the required time per section, the movement displacement of the racket, the velocity of the upper limbs joints, the physical center of gravity, and the angle and the angular velocity of the upper limbs joints between an ace player and a mediocre player, these following results were drawn. First, the experiment result of the total time required per section in a tennis flat serve motion showed that an ace player was faster than a mediocre player by 0.4 seconds. This result suggested that it was required to increase the speed of the racket head by a swift swing to perform an effective flat serve motion. Second, the experiment result of the movement displacement of the racket in the tennis flat serve motion showed that an ace player greatly moved toward the left side on an x-axis. But both an ace and a mediocre player were shown to be at the similar points on a y-axis at the moment of the impact of the racket. An ace player was also shown to be located at a higher position on a z-axis by 0.23m. Third, the velocity of the center of gravity of an ace player was faster in every phase than that of a mediocre player in a tennis flat serve motion. Fourth, the velocity of the upper limb joints of an ace player was faster in every phase than that of a mediocre player in a tennis flat serve motion. Fifth, the experiment result of the speed of the racket head in tennis flat serve motion showed that a mediocre player was faster than an ace player in the first phase, but the latter was faster than the former in the second, third, and the fourth phases. Sixth, at the moment of impact of a tennis flat serve, an ace player had greater flexion of the angle of the wrist joints by an 11.8 degree than a mediocre player. An ace player also had greater extension of the angle of the elbow joint and the shoulder joint respectively by a 5.2 degree and a 1.4 degree with a mediocre player. Seventh, an ace player had greater angular velocity of the upper limb joints and the hip joints than a mediocre player at the moment of the impact of tennis flat serve. Eighth, an ace player was shown to have a greater change of the forward and the backward inclination (or the anterior and posterior inclination) of the upper body

• Journal of Gifted/Talented Education
• /
• v.23 no.3
• /
• pp.479-499
• /
• 2013

The purpose of this study is to examine the effects of Mother's Child-Rearing Attitudes on young children intelligence, multiple intelligences and emotional intelligence. In order to achieve the purpose of the study, 215 children and their mothers and teachers of children 15 were investigated. Data analysis, correlation analysis and regression analysis were conducted to analyze the mother's Child-Rearing Attitudes and the relationship between the young children's intelligence and multiple intelligences and emotional intelligence. The results of this study and the conclusions obtained through the discussion are as follows: First, the relationship between the mother's child-rearing attitudes and intelligence, multiple intelligences, on the other hand, showed a high correlation relationship between the mother's child-rearing attitudes and emotional intelligence and appeared to be correlated with low. Second, the rejective attitude and autonomous attitude variables that best explain the entire intelligence and multiple intelligence of young children, the affectionate attitude and autonomous attitude, the young children's the entire emotional intelligence best explain the factors. These results in the development of intelligence, multiple intelligence, emotional intelligence, affectionate attitude depending on the situation, autonomous attitude shows rejective attitude avoiding uniform, certain attitudes, rather than to show the mother's Child-Rearing Attitudes desirable that suggests.