• Investigative Magnetic Resonance Imaging
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• v.16 no.1
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• pp.6-15
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• 2012

Purpose : The objective of this study was to develop background gradient correction method using excitation pulse profile compensation for accurate fat and $T_2{^*}$ quantification in the liver. Materials and Methods: In liver imaging using gradient echo, signal decay induced by linear background gradient is weighted by an excitation pulse profile and therefore hinders accurate quantification of $T_2{^*}$and fat. To correct this, a linear background gradient in the slice-selection direction was estimated from a $B_0$ field map and signal decays were corrected using the excitation pulse profile. Improved estimation of fat fraction and $T_2{^*}$ from the corrected data were demonstrated by phantom and in vivo experiments at 3 Tesla magnetic field. Results: After correction, in the phantom experiments, the estimated $T_2{^*}$ and fat fractions were changed close to that of a well-shimmed condition while, for in vivo experiments, the background gradients were estimated to be up to approximately 120 ${\mu}T/m$ with increased homogeneity in $T_2{^*}$ and fat fractions obtained. Conclusion: The background gradient correction method using excitation pulse profile can reduce the effect of macroscopic field inhomogeneity in signal decay and can be applied for simultaneous fat and iron quantification in 2D gradient echo liver imaging.

• Journal of Korea Water Resources Association
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• v.45 no.3
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• pp.275-290
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• 2012

In this study, we have developed an optimal time distribution model through extraction of peaks over threshold (POT) series. The median values for annual maximum rainfall dataset, which are obtained from the magnetic recording (MMR) and the automatic weather system(AWS) data at Seoul meteorological observatory, were used as the POT criteria. We also suggested the improved methodology for the time distribution of extreme rainfall compared to Huff method, which is widely used for time distributions of design rainfall. The Huff method did not consider changing in the shape of time distribution for each rainfall durations and rainfall criteria as total amount of rainfall for each rainfall events. This study have suggested an extracting methodology for rainfall events in each quartile based on interquartile range (IQR) matrix and selection for the mode quartile storm to determine the ranking cosidering weighting factors on minutely observation data. Finally, the optimal time distribution model in each rainfall duration was derived considering both data size and characteristics of distribution using kernel density function in extracted dimensionless unit rainfall hyetograph.

• Journal of Gifted/Talented Education
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• v.27 no.1
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• pp.17-35
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• 2017

The purpose of this study is to analyze the learning objectives characteristics of educational programs of centers for the university affiliated science-gifted education using semantic network analysis, we examined the applicability of semantic network analysis in analyzing learning objectives by comparing the results of analysis with Bloom's revised taxonomy. For this purpose, 702 learning objectives presented in 169 science subjects were selected as subjects to be analyzed. After classifying and coding the learning objectives according to Bloom's revised taxonomy, we conducted a semantic network analysis to investigate the relationship between learning objectives. The results of the analysis are as follows. First, we looked at the number of learning objectives used for each subject, and about 3 elementary school levels and about 6 middle school levels were used. Second, the knowledge dimension such as 'factual and conceptual knowledge' and cognitive process dimension such as 'remember', 'understand', and 'create' was high regardless of the research method and school level. Third, the results of analysis based on the weighting through the semantic network analysis method, the elementary school level emphasize activities th be applied to the actual experimental process through learning about scientific facts, while the middle school level emphasize the understanding of scientific facts and concepts themselves. As a result, it can be seen that the semantic network analysis can analyze characteristics of various learning objectives rather than the conventional simple statistical analysis.

• Journal of Agricultural Extension & Community Development
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• v.21 no.4
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• pp.1191-1226
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• 2014

The purpose of this study is to develop the evaluation criteria for the maintenance preserve of agriculture and rural heritage. The major steps for this study are 1) drafting the evaluation criteria for maintenance preservation of agriculture and rural heritage 2) verifying the evaluation criteria, and 3) determining the weighting values of the confirmed evaluation criteria. First, to derive the evaluation criteria for maintenance preservation of agriculture and rural heritage, the researcher reviewed the literature on the evaluation of agriculture and rural heritage, including research on the indexes of agriculture and rural heritage, the degree of the maintain preservation of heritage. A total of 31 evaluation criteria were selected. Second, to verify the selected 5 evaluation items and 31 evaluation indexes, the Delphi Method was implemented. Using traditional 3-step Delphi Method consisting of close-ended forms, with a panel of 41 experts, the researchers verified 5 evaluation items 31 evaluation indexes, two for each evaluation area validity. The confirmed evaluation areas are 5 items of management plan, management support system, surroundings of heritage, local network, heritage utilization and 31 criteria were preservation maintenance, performance plan, resident community composition, monitoring, act of parliament fulfillment, ecosystem management, landscape harmony, restoration and transmission plan and enhancement of residents' capability, etc. in the order. Through maintenance preservation evaluation index of agriculture and rural heritage, it can be utilized as sustainable development of plural resources.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.17-22
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• 2016

For the self-adaptive equalization of higher-order QAM systems, this paper proposes a new soft decision-directed (SDD) algorithm that opens the eye patterns quickly as well as significantly reducing the error level in the steady-state when it is applied to the initial equalization stage with completely closed eye patterns. The proposed method for M-QAM application minimized the computational complexity of the existing SDD by the symbol estimated based on the two symbols closest to the observation, and greatly simplified the soft decision independently of the QAM order. Furthermore, in the symbol estimating it increased the reliability of the estimates by applying the superior properties of the sigmoid function and avoiding the erroneous estimation of the threshold function. In addition, the initialization performance was improved when an error is generated to update the equalizer, weighting the symbol decision by the threshold function to the error, resulting in an extension of the range of error fluctuations. As a result, the proposed method improves remarkably the computational complexity and the properties of initialization and convergence of the traditional SDD. Through simulations for 64-QAM and 256-QAM under multipath channel conditions with additive noise, the usefulness of the proposed methods was confirmed by comparing the performance of the proposed 2-SDD and two forms of weighted 2-SDD with CMA.

• Korean Journal of Community Nutrition
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• v.14 no.5
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• pp.565-575
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• 2009

The purpose of this study was to propose the appropriate sizes and dish combination for nutritional-balanced lunch boxes delivered to children under the government-funded meal service program in Korea. The study was based on the 3 : 1 : 2 Meal Box Magic, a nutrition education method developed in Japan. A total of 290 lunch menus, comprising of 10 day menus from 29 organizations having delivered lunch boxes to children during summer vacation of 2008, were analyzed and used as the base data for lunch box combination. Dishes of the menus were classified into 6 groups: Rice group, Protein side dish group (including meat, fish, egg, and bean dishes), Vegetable side dish group, Kimchi group (including kimchi and jangajji), Soup stew group, and the other group. Nutrient analysis was conducted for 100 ml of these dishes by CAN Pro 3.0 utilizing volume and weight conversion data used for analysis of the Korea Health and Nutrition Examination Survey and those from the Nutrient Composition of Food for Consumers. All the possible combinations of 5 dishes, comprising of 3 dishes from Rice group, Protein side dish group, and Kimchi group, respectively, and 2 dishes from Vegetable side dish group, were made using the frequently served dishes from the respective dish group. Nutrient analysis of each combination was conducted based on the assumption that a lunch box was 600 ml and filled up to 80% by dishes using the volume ratio of 3 : 1 : 1.5 : 0.5 for Rice group : Protein side dish group : Vegetable side dish group : Kimchi group. The mean and standard deviation of energy and nutrients of all combinations calculated by weighting the serving frequency of each dish selected for the combinations were $621\pm81$ kcal for Energy, $22.1\pm5.0$ g for Protein, $120\pm45$ mg for Calcium, $4.1\pm1.1$ mg for Iron, $201\pm130\;{\mu}g$ RE for Vitamin A, $0.34\pm0.10$ mg for Thiamin, $0.27\pm0.10$ mg for Riboflavin, and $24.3\pm9.6$ mg for Vitamin C. The energy percentages from Carbohydrate, Protein and Fat were 66%, 14% and 20%. The analysis results met the nutrition standard of lunch boxes for male elementary students in grades 4 through 6 under the government-funded meal service program regarding calories, nutrients except calcium and riboflavin, and macronutrient distribution ranges. Accordingly appropriate box sizes were suggested for different age and sex groups to meet the respective nutrition standards. In addition, milk or dairy products were suggested to accompany lunch boxes to supplement calcium and riboflavin intake. The method of selecting box sizes and making dish combination suggested in this study could be useful for the organizations preparing lunch boxes under the government-funded children's meal service program where nutrition professionals are not available.

• Journal of Korean Society of Transportation
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• v.36 no.2
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• pp.98-111
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• 2018

Truck platooning, which is a cluster of trucks in support of vehicle-to-vehicle communication and automated longitudinal vehicle control, is a promising method to both operational efficiency and prevent traffic crashes. Although a variety of studies have been conducted to identify the effects of vehicle platooning on traffic stream, we are not aware of any study attempting to identify promising road segments for vehicle platooning. This study aims to develop a methodology for determining the priority of freeway segments that would potentially lead to maximize the effectiveness of truck platooning. Evaluation measures derived in this study includes truck crash rates, the percentage of truck traffic, segment length, and the number of entry and exit points. Weighting values obtained from an analytical hierarchical process (AHP) method were applied to compute the proposed priority score to determine better freeway segment for truck platooning. Results suggested that a 46.9km freeway segment, from Sacheon IC to Sanin JC, was the most promising segment for maximizing the effectiveness of truck platooning. It is expected that the outcome of this study would be effectively used as a fundamental to establish operational strategies for truck platooning.

• International Journal of Automotive Technology
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• v.4 no.2
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• pp.77-86
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• 2003

How to compare the environmental damage caused by vehicles with different foe]s and drive trains\ulcorner This paper describes a methodology to assess the environmental impact of vehicles, using different approaches, and evaluating their benefits and limitations. Rating systems are analysed as tools to compare the environmental impact of vehicles, allowing decision makers to dedicate their financial and non-financial policies and support measures in function of the ecological damage. The paper is based on the "Clean Vehicles" research project, commissioned by the Brussels Capital Region via the BIM-IBGE (Brussels Institute for the Conservation of the Environment) (Van Mierlo et at., 2001). The VriJe Universiteit Brussel (ETEC) and the universite Libre do Bruxelles (CEESE) have jointly carried out the workprogramme. The most important results of this project are illustrated in this paper. First an overview of environmental, economical and technical characteristics of the different alternative fuels and drive trains is given. Afterward the basic principles to identify the environmental impact of cars are described. An outline of the considered emissions and their environmental impact leads to the definition of the calculation method, named Ecoscore. A rather simple and pragmatic approach would be stating that all alternative fuelled vehicles (LPG, CNG, EV, HEV, etc.) can be considered as ′clean′. Another basic approach is considering as ′clean′ all vehicles satisfying a stringent omission regulation like EURO IV or EEV. Such approaches however don′t tell anything about the real environmental damage of the vehicles. In the paper we describe "how should the environmental impact of vehicles be defined\ulcorner", including parameters affecting the emissions of vehicles and their influence on human beings and on the environment and "how could it be defined \ulcorner", taking into account the availability of accurate and reliable data. We take into account different damages (acid rain, photochemical air pollution, global warming. noise, etc.) and their impacts on several receptors like human beings (e.g., cancer, respiratory diseases, etc), ecosystems, or buildings. The presented methodology is based on a kind of Life Cycle Assessment (LCA) in which the contribution of all emissions to a certain damage are considered (e.g. using Exposure-Response damage function). The emissions will include oil extraction, transportation refinery, electricity production, distribution, (Well-to-Wheel approach), as well as the emission due to the production, use and dismantling of the vehicle (Cradle-to-Grave approach). The different damages will be normalized to be able to make a comparison. Hence a reference value (determined by the reference vehicle chosen) will be defined as a target value (the normalized value will thus measure a kind of Distance to Target). The contribution of the different normalized damages to a single value "Ecoscore" will be based on a panel weighting method. Some examples of the calculation of the Ecoscore for different alternative fuels and drive trains will be calculated as an illustration of the methodology.

• Journal of Korean Society of Forest Science
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• v.103 no.1
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• pp.137-146
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• 2014

We have developed the Forest Carbon Sink Index on afforestation and reforestation activities, a regulation stated in article 26 of the 'Law on the maintenance and enhancement of carbon sink (Carbon Sink Law)', which took effect on March, 2013. According to the legal purpose to evaluate the performance of individual forest carbon offset projects and to compare each other at a certain point, values of the forest carbon sink index were calculated by the scoring method. Three criteria were established based on the Carbon Sink Law: 'Carbon' (real greenhouse gas reduction), 'Human' (socio-economic effect) and 'Nature' (environmental effect). Continuously, 9 indicators from the three criteria were selected by top-down approach; the adequacy of each criteria and indicators were reviewed through on-line Delphi survey; and finally weighted value of each criteria and indicators were assigned. To reflect the characteristics of the domestic forest carbon offset projects, which focus on corporate social responsibility-typed projects, we applied the score weighting method to minimize gaps among criteria and ones among indicators. After applying our newly developed forest carbon sink index to five domestic forest carbon offset projects, we could confirm that the criteria of 'Human' and 'Nature', which criteria are in relatively low weight, can play a role as an actual incentive to reduce negative socio-economic and environmental impacts. Based on performance evaluation of the five forest carbon offset project by the forest carbon sink index, the best or good performance project developers could be rewarded, and further the performance evaluation would work as an incentive to stimulate the involvement of domestic project developers in the field of forest carbon offset project.

• Journal of Biomedical Engineering Research
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• v.19 no.4
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• pp.385-391
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• 1998

A new balancing method of atrial pressures balancing for the moving actuator total artificial heart(TAH) without an extra compliance chamber was developed. The asymmetric operation of the pendulous moving actuator have made it possible to compensate the left and right pump output difference by utilizing the interventricular air space as an internal compliance chamber in a pump housing. Furthermore, the balancing performance between left and right pump outputs is increased through the improvement of the flexibility of part of the polyurethane housing. However, the increase of the flexibility of the pump housing causes a little loss of the cardiac output due to the reduction of active filling property. In this paper., a good condition between the balance and pump output performance is evaluated by adjusting the air volume in the interventricular space through a series of in vitro experiments. This new pump was implanted in a sheep weighting 63kg, and it survived for 3 days and the average cardiac output during postoperative days was about 4.2 L/mim with the atrial pressures under 15 mmHg.