• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.88.1-88.1
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• 2012

Silicon nanowires (SiNWs), due to their unusual quantum-confinement effects that lead to superior electrical and optical properties compared to those of the bulk silicon, have been widely researched as a potential building block in a variety of novel electronic devices. The conventional means for the synthesis of SiNWs has been the vapor-liquid-solid method using chemical vapor deposition; however, this method is time consuming, environmentally unfriendly, and do not support vertical growth. As an alternate, the electroless etching method has been proposed, which uses metal catalysts contained in aqueous hydrofluoric acids (HF) for vertically etching the bulk silicon substrate. This new method can support large-area growth in a short time, and vertically aligned SiNWs with high aspect ratio can be readily synthesized with excellent reproducibility. Nonetheless, there still are rooms for improvement such as the poor surface characteristics that lead to degradation in electrical performance, and non-uniformity of the diameter and shapes of the synthesized SiNWs. Here, we report a facile method of SiNWs synthesis having uniform sizes, diameters, and shapes, which may be other than just cylindrical shapes using a modified nanosphere lithography technique. The diameters of the polystyrene nanospheres can be adjustable through varying the time of O2 plasma treatment, which serve as a mask template for metal deposition on a silicon substrate. After the removal of the nanospheres, SiNWs having the exact same shape as the mask are synthesized using wet etching technique in a solution of HF, hydrogen peroxide, and deionized water. Different electrical and optical characteristics were obtained according to the shapes and sizes of the SiNWs, which implies that they can serve specific purposes according to their types.

• Journal of Biosystems Engineering
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• v.42 no.3
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• pp.227-233
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• 2017

Purpose: Morphological properties of soybean roots are important indicators of the vigor of the seed, which determines the survival rate of the seedlings grown. The current vigor test for soybean seeds is manual measurement with the human eye. This study describes an application of a machine vision technique for rapid measurement of soybean seed vigor to replace the time-consuming and labor-intensive conventional method. Methods: A CCD camera was used to obtain color images of seeds during germination. Image processing techniques were used to obtain root segmentation. The various morphological parameters, such as primary root length, total root length, total surface area, average diameter, and branching points of roots were calculated from a root skeleton image using a customized pixel-based image processing algorithm. Results: The measurement accuracy of the machine vision system ranged from 92.6% to 98.8%, with accuracies of 96.2% for primary root length and 96.4% for total root length, compared to manual measurement. The correlation coefficient for each measurement was 0.999 with a standard error of prediction of 1.16 mm for primary root length and 0.97 mm for total root length. Conclusions: The developed machine vision system showed good performance for the morphological measurement of soybean roots. This image analysis algorithm, combined with a simple color camera, can be used as an alternative to the conventional seed vigor test method.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.319-323
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• 1991

To determine how closely related to field lodging for several characters affecting the field lodging for several characters affecting field lodging, and to obtain the basic information for selection of lodging resistance genotype, an experiment was conducted with 10 varieties from May to Oct., 1990 at the experimental field in Sunchon Xational University. Culm length, dry weight per unit culm length (W/1), bending moment per unit culm diameter (W1/d), lodging index (L), bending load ratio (W1/P), and index of critical lodging load(W$_{s}$$^{2}$/1$^4$) were the most closely related characters to field lodging. Culm length showed highly significant positive correlation coefficient with field lodging(r=0.7607), but it may be undesirable to judge lodging resistance of genotype by culm length itself without consideration of culm stiffness. Considering the difficulty and time-consuming to measure the character, clum length, W/1, W1/d, and W$_{s}$$^{2}$/1$^4$ were easy to measure and hence would be the most useful variables to judge the lodging resistance of genotype. Culm diameter, cross sectional area of culm, thickness of culm wall, and the second inertia moment of cross section of culm were not correlated with field lodging at all. Breaking strength of culm showed significantly negative correlation coefficient (r=-0.3986) with field lodging.ing.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.3
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• pp.29-40
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• 2012

The method regarding obtaining various kinds of attribute data of spatial information, including that of digital map, is normally restricted to Geographic survey that deals with in-field surveys. Geographic surveying for drawing digital map, however, require much effort due to the fact that a surveyor has to characterize geographic features individually in the field. Not only does the Geographic survey cover large area, but also its need for manual drawing and surveying using Draft map makes it more expensive and time-consuming. Though some recent Geographic surveys take advantage of MMS(Mobile Mapping System) to collect computerized information, there are inevitable limits in creating digital map with such data. This research will analyze the problems in current Geographic surveys and suggest adequate methods and standards for Geographic surveys by researching the methods of domestic/international service organizations that deal with establishing spatial information. This study therefore will aim to enhance the efficiency of creating digital map and Geographic survey, which would ultimately maximize the applicability of pan-national digital map by improving reliability of digital map and upgrading the utilizability of Geographic survey data.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.3
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• pp.101-108
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• 2012

The construction of data connection is required due to the digital map do not have the new address data which is implemented by the Korea government and it cannot use between government and other agency. The manually matching of digital map and new address data is time and money consuming process due to the huge amount of data. In this research, new system is developed for data generation of attribute data by the data connection method of digital map and new address data using spatial matching and matching rate of data connection is analyses. The results of data matching rate in the research area are 84% in building case and 67% in road case in 1:1000 digital map at Suwon and 18% in building case and 21% in road at Seogwipo.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.3
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• pp.77-85
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• 2007

Assessment of soil erosion is a cost and time-consuming task. There are many models developed to predict soil erosion from an area, but Universal Soil Loss Equation (USLE) is most widely used empirical equation for estimating annual soil erosion. Soil erosion depends upon-rainfall intensity, type of soil, land cover and land use, slope degree, slope length and soil conservation practice. All these parameters are have spatial distribution and hence satellite remote sensing and Geographic Information System (GIS) are applicable in the assessment of the influence on soil erosion. GIS has been integrated with the USLE (Universal Soil Loss Equation) model in identification of rainfall-based erosion to the Bocheong River which is the representative basin of IHP due to Typhoon Rusa. Similar studies are available in literature, ranging from those that use a simple model such as USLE to others of a more sophisticated nature.

• The KIPS Transactions:PartD
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• v.15D no.4
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• pp.531-540
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• 2008

An Adaptive Random Testing(ART) is one of test case generation algorithms, which was designed to get better performance in terms of fault-detection capability than that of Random Testing(RT) algorithm by locating test cases in evenly spreaded area. Two ART algorithms, such as Distance-based ART(D-ART) and Restricted Random Testing(RRT), had been indicated that they have significant drawbacks in computations, i.e., consuming quadratic order of runtime. To reduce the amount of computations of D-ART and RRT, iterative partitioning of input domain strategy was proposed. They achieved, to some extent, the moderate computation cost with relatively high performance of fault detection. Those algorithms, however, have yet the patterns of non-uniform distribution in test cases, which obstructs the scalability. In this paper we analyze the distribution of test cases in an iterative partitioning strategy, and propose a new method of input domain enlargement which makes the test cases get much evenly distributed. The simulation results show that the proposed one has about 3 percent of improvement in terms of mean relative F-measure for 2-dimension input domain, and shows 10 percent improvement for 3-dimension space.

• Journal of Korean Clinical Nursing Research
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• v.18 no.2
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• pp.251-263
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• 2012

Purpose: It was necessary for developing a neonatal classification system based on nursing needs and direct care time. This study was, thus, aimed at identifying nursing activities and measuring the standard nursing practice time for developing a neonatal patient classification system in Neonatal Intensive Care Unit (NICU). Methods: The study was taken place in 8 general hospitals located in Seoul and Kyungi province, South Korea from Dec, 2009 to Jan, 2010. By using 'the modified Workload Management System for critical care Nurses' (WMSN), nursing categories, activities, standard time, and task frequencies were measured with direct observation. The data were analyzed by using descriptive statistics. Results: Neonatal nursing activities were categorized into 8 areas: vital signs (manual), monitoring, activity of daily living (ADL), feeding, medication, treatment and procedure, respiratory therapy, and education-emotional support. The most frequent and time-consuming area was an ADL, unlike that of adult patients. Conclusion: The findings of the study provide a foundation for developing a neonatal patient classification system in NICU. Further research is warranted to verify the reliability and validity of the instrument.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.2
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• pp.123-134
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• 2013

Urban underground structures at low ground elevations (i.e. shallow substructures) unlike typical tunnel structures are subjected to low overburden and high water pressures. This often causes the underground structures to become damaged. Various conventional methods for the urban underpass structures such as dead weight increasement, round anchors, and tension piles, are significantly conservative and provok concerns about the costly, time-consuming installation process. Recently, permanent drainage system becomes to widely use for supplementing the conventional method's shortcomings, but, it is applied without the considerations for ground conditions and water table. In this study, therefore, numerical analyses are performed with various parameters such as groundwater level, wall height, and ground conditions in order to establish design guidelines for induced drainage system which is a kind of the permanent drainage method constructed at the Y-area. According to the numerical results, the induced drainage system is very effective in reducing the uplift pressure that acts on the base of underpass structures.

• Korean Journal of Community Nutrition
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• v.22 no.1
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• pp.1-12
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• 2017

Objectives: The present study aimed to investigate high school students' sugar intake behaviors, the status of consuming sugary processed foods, the awareness of sugar, and the experience and interest in sugar-related education based on the level of sugar-related nutrition knowledge. Methods: In this study, five high schools were selected in Seoul, Korea, and a survey was conducted in 400 students on the level of sugar-related nutrition knowledge and sugar intake status. A total of 349 questionnaires were used for the final analysis. For statistical analysis, descriptive statistics was performed; a t-test, ${\chi}^2$ test, and Friedman test were used for comparative analysis. Results: The study results showed a positive association between the knowledge level of sugar and the appropriate sugar intake behavior and sugary food choices. The group with more nutrition knowledge on sugar was found to have good eating habits and to eat less sugary food. The main sources of sugar were beverages, confectionary, and bakery goods in the corresponding order, irrespective of the level of nutrition knowledge related to sugar. A significant difference was found in the groups' awareness of the sugar content of the drinks with 89.4% for the higher-knowledge group, and only 81.5% for the lower-knowledge group (p < 0.05). Results also showed that 43.9% of the higher-knowledge group and 36.4% of the lower knowledge group were interested in participating in education on sugar. Conclusions: This study result indicated the need to help adolescents to avoid excessive sugar intake from only certain favorite foods. Therefore, it is necessary to seek a systematic foundation for participatory education in order for them to maintain a low sugar intake in daily life and lead healthy eating habits by increasing their level of sugar-related information and knowledge.