• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1279-1288
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• 2023

Recently, domestic leisure boats have been actively researching eco-friendly product development to enter the global market. Since the hulls of existing leisure boats are mainly made of fiber reinforced plastic (FRP) or aluminum, design techniques for securing structural safety by applying related materials have been mainly studied. In this study, an initial structural design safety assessment of a trimaran pontoon leisure boat with a modular hull structure and eco-friendly high-density polyethylene (HDPE) material was conducted, and sensitivity evaluation and optimization analysis for lightweight design were performed. The initial structural design safety assessment was carried out by creating a finite element analysis model and applying the loading conditions specified in the ship classification regulation to check whether the specified allowable stresses are satisfied. For the sensitivity evaluation, the influence of stress and weight of each hull structural member was evaluated using the orthogonal array design of experiments method, and an approximate model based on the response surface method was generated using the results of the design of experiments. The optimization analysis set the thickness of the hull structural members as the design variable and considered the optimal design formulation to minimize the weight while satisfying the allowable stress. The algorithm of the optimization analysis applied the Gradient-population Based Optimizer (GBO) to improve the accuracy of the optimal solution convergence while reducing the numerical cost. Through this study, the optimal design of a newly developed eco-friendly trimaran pontoon leisure boat with a weight reduction of 10% was presented.

• Journal of Nutrition and Health
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• v.45 no.1
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• pp.30-43
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• 2012

Patients undergoing peritoneal dialysis are at risk for protein-energy malnutrition because of nutrient losses during dialysis. This study determined the nutritional status of patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Forty-four patients receiving CAPD were divided into two groups according to dialysis period. We investigated the nutritional status of the patients by measuring anthropometric and biochemical parameters, as well as food intake, self-appetite, dietary habits, a subjective global assessment, and a total nutritional status assessment. Group I subjects (7 males, 13 females) had received dialysis for < 2 years, whereas the group II subjects (18 males, 6 females) received dialysis for ${\geq}$ 2 years. Energy intake with added dextrose in the dialysate per kg of body weight was $30.3{\pm}5.8$ kcal in group I and $29.0{\pm}8.1$ kcal in group II. The average protein intake per kg of weight was $1.0{\pm}0.3$ g in group I and $1.0{\pm}0.4$ g in group II, which were less than the recommended protein intake for patients undergoing CAPD (1.2-1.5 g/kg). Mean serum albumin level was significantly lower in group II than that in group I (p < 0.05). A recent self-appetite score was significantly higher in group II than that in group I (p < 0.01). The dietary habits score was significantly lower in group II than that in group I (p < 0.05). The subjective global assessment was significantly higher in group I (85.0%) than that in group II (54.2%) under normal nutrition status (p < 0.05). The dialysis period was significantly and negatively correlated with the subjective global assessment (r = -0.502, p < 0.01) and the total nutritional status assessment (r = -0.575, p < 0.01). These results demonstrated that patients undergoing CAPD for ${\geq}$ 2 years had worse nutritional status than those who had been undergoing dialysis for < 2 years. Good nutritional status can predict the long-term survival of patients undergoing peritoneal dialysis. Additionally, the exact evaluation of nutritional status before 2 years will be important to maintain long-term dialysis therapy in patients undergoing CAPD.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.363-370
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• 2014

We grew seedlings of Saechucheongbyeo and Odaebyeo of rice cultivars that are cultivated dominantly in the northern and middle regions of Korea under control(ambient condition), ambient $CO_2$ concentration+elevated temperature, and elevated $CO_2$ concentration+elevated temperature in order to study how growth responses and crop yield of major rice of Korea change as the global warming proceeds and compared the results. Aboveground biomass, belowground biomass, total biomass, and panicles weight per individual and ripended grain rate of cv. Saechucheongbyeo were the highest under control, but those of cv. Odaebyeo were the highest under elevated $CO_2$ concentration+elevated temperature. There was no difference in the number of panicles per individual of cv. Saechucheongbyeo and cv. Odaebyeo in these experiments. There was no difference in the number of grains per panicle of cv. Saechucheongbyeo among three environmental gradients, but that of cv. Odaebyeo was the highest under elevated $CO_2$ concentration+elevated temperature. Weight of a grain of cv. Saechucheongbyeo was highest under elevated $CO_2$ concentration+elevated temperature, but that of cv. Odaebyeo was the higher under ambient $CO_2$ concentration+elevated temperature and elevated $CO_2$ concentration+elevated temperature. Thus, if global warming continues in Korea, selection of rice cultivation varieties must be chosen carefully for commendation.

• Journal of KIISE:Software and Applications
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• v.34 no.1
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• pp.1-10
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• 2007

This paper proposes a new indexing mechanism for MPEG-7 visual descriptors, especially Dominant Color and Contour Shape descriptors, that guarantees an efficient similarity search for the multimedia database whose visual meta-data are represented with MPEG-7. Since the similarity metric used in the Dominant Color descriptor is based on Gaussian mixture model, the descriptor itself could be transform into a color histogram in which the distribution of the color values follows the Gauss distribution. Then, the transformed Dominant Color descriptor (i.e., the color histogram) is indexed in the proposed indexing mechanism. For the indexing of Contour Shape descriptor, we have used a two-pass algorithm. That is, in the first pass, since the similarity of two shapes could be roughly measured with the global parameters such as eccentricity and circularity used in Contour shape descriptor, the dissimilar image objects could be excluded with these global parameters first. Then, the similarities between the query and remaining image objects are measured with the peak parameters of Contour Shape descriptor. This two-pass approach helps to reduce the computational resources to measure the similarity of image objects using Contour Shape descriptor. This paper also proposes two integration schemes of visual descriptors for an efficient retrieval of multimedia database. The one is to use the weight of descriptor as a yardstick to determine the number of selected similar image objects with respect to that descriptor, and the other is to use the weight as the degree of importance of the descriptor in the global similarity measurement. Experimental results show that the proposed indexing and integration schemes produce a remarkable speed-up comparing to the exact similarity search, although there are some losses in the accuracy because of the approximated computation in indexing. The proposed schemes could be used to build a multimedia database represented in MPEG-7 that guarantees an efficient retrieval.

• Korean Journal of Environment and Ecology
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• v.24 no.6
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• pp.648-656
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• 2010

Global warming brings changes of natural ecosystems and affects on the plant growth response. Quercus acutissima and Q. variabilis are taxonomically similar and dominant native species in deciduous forests in South Korea. In order to understand the growth response of Q. acutissima and Q. variabilis to global warming condition, we cultivated the seedling of the two oak species in ambient condition(control) and treatment with elevated $CO_2$(700~800ppm) and increased air temperature(approximately $3^{\circ}C$ above than control). Then we measured the growth characteristic among them and analyzed the relationship between two species using PCA ordination. Stem length and total plant weight of Q. acutissima were significantly affected by elevated $CO_2$ concentration and increased air temperature. Stem diameter and weight of Q. variabilis were significantly affected by elevated $CO_2$ concentration and increased air temperature(p<0.05). The variation characteristics of Q. acutissima were changed more than Q. variabilis by elevated $CO_2$ concentration and increased air temperature. These result suggested that Q. acutissima was more sensitive to global warming situation than Q. variabilis in central region of Korea. PCA ordination showed that two species were arranged by two distinct groups based on 10 characters by elevated $CO_2$ and increased air temperature.

• Journal of the Korean association of regional geographers
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• v.2 no.2
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• pp.75-92
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• 1996

Geography education is one of the best ways to improve the understanding of other countries. By analyzing Korean and Japanese textbooks on world geography, I tried to find out how well they explain the other country and to set forth guiding principles for geography education. To achieve these aims, weight analysis are used. The major findings in this study can be summarised as follow. The contents of Korean and Japanese geography textbooks were analyzed deviding into 2 major topics, 6 minor topics, and 20 key concepts. (1) By analyzing Korean geography textbook of the 5th curriculum the weight percentages which had been given to each minor topics were found. They are as follow: resource problem(57.7%), human right problem(21.4%), population problem (9.0%), mutual dependence(6.0%), environmental problem(3.3%), international competition(2.6%). (2) By analyzing Korean geography text-book of the 6th curriculum the weight percentages which had been give to each minor topics were found. They are as follow: resource problem(42.7%), human right problem(21.7%), mutual dependence (20.9%), environmental problem(7.7%), population problem(4.6%), international competition(2.4%) (3) By analyzing Japanise geography text-book of 5th curriculum ammendment the weight percentages which had been give to each minor topics were found. They are as follows: resource problem(49.9%) human right problem(21.7%), mutual dependence(15.5%), population problem (7.1%), international competition(6.2%), environmental problem(3.8%) (4) By analyzing Japanise geography textbook of 6th curriculum ammendment the weight percentages which had been give to each minor topics were found. They are as follows human right problem (31.6%), mutual dependence(22.8%), resource problem(20.7%), population problem(12.7%), environmental problem(8.6%), international competition(3.6%). We can see that in the field of dependence Korea and Japan put the similar weight but in the field of common problem they put the fairly different weight. It can be viewed as the difference of curriculum. That is to say Korea used both the systematic method on the basis of unit but Japan used only topical method on the basis of unit. Therefore Korean geography textbook introduce agriculture, forestry, fishery, mining industry and manufacturing industry. Japanese textbook, however gives a detailed account about residents' lives in specific area. For that reason in Korean textbook, resource was stressed, while in Japanese textbook, culture was stressed.

• Journal of Computational Design and Engineering
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• v.1 no.3
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• pp.187-193
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• 2014

One of the hottest challenges in automotive industry is related to weight reduction in sheet metal forming processes, in order to produce a high quality metal part with minimal material cost. Stamping is the most widely used sheet metal forming process; but its implementation comes with several fabrication flaws such as springback and failure. A global and simple approach to circumvent these unwanted process drawbacks consists in optimizing the initial blank shape with innovative methods. The aim of this paper is to introduce an efficient methodology to deal with complex, computationally expensive multicriteria optimization problems. Our approach is based on the combination of methods to capture the Pareto Front, approximate criteria (to save computational costs) and global optimizers. To illustrate the efficiency, we consider the stamping of an industrial workpiece as test-case. Our approach is applied to the springback and failure criteria. To optimize these two criteria, a global optimization algorithm was chosen. It is the Simulated Annealing algorithm hybridized with the Simultaneous Perturbation Stochastic Approximation in order to gain in time and in precision. The multicriteria problems amounts to the capture of the Pareto Front associated to the two criteria. Normal Boundary Intersection and Normalized Normal Constraint Method are considered for generating a set of Pareto-optimal solutions with the characteristic of uniform distribution of front points. The computational results are compared to those obtained with the well-known Non-dominated Sorting Genetic Algorithm II. The results show that our proposed approach is efficient to deal with the multicriteria shape optimization of highly non-linear mechanical systems.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.6 s.119
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• pp.39-53
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• 2007

Unlike conventional roof landscaping, where various kinds of plants and structures are employed, a grass roof is a roof on which herbaceous plants are grown in planting medium and which is not accessed or maintained, mainly because it doesn't have sufficient load capacity to support a regular roof garden. They are mostly built on existing roofs, whether flat slab or gabled. Planting on roofs has numerous advantages, such as creating a biotope, purifying urban air, adding moisture to the atmosphere, storing rain water, preventing flash floods, reducing energy use for heating and air conditioning, enhancing the urban landscape and providing relaxation to the city dwellers, not to mention the alleviation of global warming by absorbing $CO_2$. In addition to the general merits of roof planting, the grass roof has its own unique qualities. Only herbaceous species are planted on the roof, resulting in light weight which allows roofs of existing buildings to be planted without structural reinforcement. The species chosen are mostly short, tough perennials that don't need to be maintained. These conditions provide an ideal situation where massive planting can be done in urban areas where roofs are often the only and definitely the largest space available to be planted. If roofs are planted on a massive scale they can play a significant role in alleviating global warming, heat island effects and energy shortages. Despite the advantages of grass roofs, there are some problems. The most significant problem is the invasion of neighboring plants. They may be brought in with the planting medium, by birds or by wind. These plants have little aesthetic value comparing to the chosen species and are usually taller. Eventually they dominate and prevail over the original species. The intended planting design disappears and the roof comes to look wild. Since the primary value of a grass roof is ecological, a change in attitude towards what constitutes beauty on the roofscape is necessary. Instead of keeping the roof neat through constant maintenance, people must learn that the wild grass with bird's nests on their roof is more beautiful as it is.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.83-94
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• 2016

Energy use has been recognized worldwide as a main cause of global warming and it is at the center of climate change. In this study, problems and measures of zero-energy building construction are investigated and analyzed. Based on the results, evaluation criteria of the zero-energy building are suggested. Performance related factors(Q) representing the environmental grade were divided into three categories as outdoor, indoor environment and maintenance. Energy related factors(LR) representing the energy load were divided into an energy, materials & resources, water cycle management, land use and transportation. Detailed fifty three items are listed for the evaluation under the consideration of energy, water cycle management sections gave weight. Upon receiving the first in the environment friendly certification system, Seoul Central Post Office and Seoul Metropolitan Water Supply Center evaluated. The reason why this score difference is due to lack of use of new generation energy building construction is required expensive costs so need expansion of governmental support. This effort is successful zero energy building construction and copes with global warming and climate change.

• Food Science of Animal Resources
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• v.38 no.3
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• pp.554-569
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• 2018

This study aimed to investigate the physiological characteristics and anti-obesity effects of Lactobacillus plantarum K10. The ${\alpha}-amylase$ inhibitory activity, ${\alpha}-glucosidase$ inhibitory activity, and lipase inhibitory activity of L. plantarum K10 was $94.66{\pm}4.34%$, $99.78{\pm}0.12%$, and $87.40{\pm}1.41%$, respectively. Moreover, the strain inhibited the adipocyte differentiation of 3T3-L1 cells ($32.61{\pm}8.32%$) at a concentration of $100{\mu}g/mL$. In order to determine its potential for use as a probiotic, we investigated the physiological characteristics of L. plantarum K10. L. plantarum K10 was resistant to gentamycin, kanamycin, streptomycin, ampicillin, ciprofloxacin, tetracycline, vancomycin, and chloramphenicol. It also showed higher Leucine arylamidase, Valine arylamidase, and ${\beta}-galactosidase$ activities. Moreover, it was comparatively tolerant to bile juice and acid, exhibiting resistance to Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus with rates of 90.71%, 11.86%, 14.19%, and 23.08%, respectively. The strain did not produce biogenic amines and showed higher adhesion to HT-29 cells compared to L. rhamnosus GG. As a result of the animal study, L. plantarum K10 showed significantly lower body weight compared to the high-fat diet group. The administration of L. plantarum K10 resulted in a reduction of subcutaneous fat mass and mesenteric fat mass compared to the high-fat diet (HFD) group. L. plantarum K10 also showed improvement in gut permeability compared to the HFD positive control group. These results demonstrate that L. plantarum K10 has potential as a probiotic with anti-obesity effects.