• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.3
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• pp.305-315
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• 2010

This research aims to develop a method to determine the 3D coordinates of an object point from overlapping omni-directional images acquired by a ground mobile mapping system and assess their accuracies. In the proposed method, we first define an individual coordinate system on each sensor and the object space and determine the geometric relationships between the systems. Based on these systems and their relationships, we derive a straight line of the corresponding object point candidates for a point of an omni-directional image, and determine the 3D coordinates of the object point by intersecting a pair of straight lines derived from a pair of matched points. We have compared the object coordinates determined through the proposed method with those measured by GPS and a total station for the accuracy assessment and analysis. According to the experimental results, with the appropriate length of baseline and mutual positions between cameras and objects, we can determine the relative coordinates of the object point with the accuracy of several centimeters. The accuracy of the absolute coordinates is ranged from several centimeters to 1 m due to systematic errors. In the future, we plan to improve the accuracy of absolute coordinates by determining more precisely the relationship between the camera and GPS/INS coordinates and performing the calibration of the omni-directional camera

• Journal of the Korea Society of Computer and Information
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• v.12 no.4
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• pp.269-277
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• 2007

Wireless sensor network system is expected to get high attention in research for now and future owing to the advanced hardware development technology and its various applicabilities. Among variety of sensor network systems, the seashore and marine sensor network, which are extended to get sampling of marine resources, environmental monitoring to prevent disaster and to be applied to the area of sea route guidance. For these marine applications to be available, however, the provision of precise location information of every sensor nodes is essential. In this paper, the sequential localization algorithm for obtaining the location information of marine sensor nodes. The sequential localization is done with the utilization of a small number of beacon nodes along the seashore and gets the location of nodes by controling the sequences of localization and also minimizes the error accumulation. The key idea of this algorithm for localization is that the localization priority of each sensor nodes is determined by the number of reference nodes' information. This sequential algorithm shows the improved error performance and also provide the increased coverage of marine sensor network by enabling the maximum localization of sensor nodes as possible.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.4
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• pp.267-274
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• 2001

A prototype experiment on the anchovy boat seine was carried out in the southern sea of korea to analyze the vertical opening and the underwater geometry. The vertical opening and the underwater geometry of the prototype net were determined by distance of Minilog position with the combinations of the distance between paired boats and the towing speed. The results osbtained can be summarized as follows; 1. Vertical opening of the protype net was gradually lowered according to the increase of the distance between paired beats and the towing speed. 2. Vertical opening of Wing net, Inside wing net, Square, Fore bag net, Flapper and After bag net of the prototype net according to the distance between paired boats were varied in the range of 8.4~9.0, 15.7~17.4, 12.9~17.9, 13.6~19.0, 8.3~8.4, 11.1~14.7m respectively, varied in the range of 12~16, 22~24, 27~38, 59~83, 92~93, 41~54% of the normal opening respectively. 3. Vertical opening of Wing net, In side wing net, Square, Fore bag net, Flapper and After bag net of the prototype net according to the towing speed were varied in the range of 7.7~10.5, 19.6~21.6, 12.2~16.9, 15.4~17.1, 8.0~8.2, 13.7~14.7m respectively, varied in the range of 14~19, 27~30, 32~36, 67~74, 89~91, 51~54% of the normal opening respectively. 4. Prototype net was appeared apparent the pocket shape, because Wing net and Inside wing net was opened 20% of the normal opening. 5. Working depth of the prototype net was gradually shallow according to the increase of the distance between paired boats and the towing speed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.2
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• pp.203-211
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• 2015

The purpose of this study is to identify the flow resistance of the bottom pair trawl nets. The bottom pair trawl nets being used in fishing vessel (100G/T, 550ps) was selected as a full-scale net, and 1/10, 1/25 and 1/50 of the model nets were made. Converted into the full-scale net by Tauti's modeling rule and Kim's modeling rule, when resistance coefficient k of each net was calculated by substituting into above equation for flow resistance R and wall area of nets S values of each net ${\upsilon}$. Because resistant coefficient k decreases exponentially according as flow velocity ${\upsilon}$ increases to make $k=c{\upsilon}^{-m}$, c and m values of each net were compared. As a result, as the model was smaller, c and m values was smaller in the two rule into standard of 1/10 model value, decrease degree of 1/25 model was almost same in the two rule, decrease degree of 1/50 model was very big in Tauti's modeling rule. Therefore, in the result of experiment, because average of c and m values for similarly 1/10 and 1/25 model were given $c=4.9(kgf{\cdot}s^2/m^4)$ and m=0.45, R (kgf) of bottom pair trawl net could show $R=4.9S{\upsilon}^{1.55}$ using these values. As in the order of cod-end, wing and bag part for 1/25 and 1/50 model net were removed in turn, measured flow resistance of each, converted into the full-scale, total resistance of the net and the resistance of each part net were calculated. The resistance ratio of each part for total net was not same in 1/25 and 1/50 model each other, but average of two nets was perfectly same area ratio of each part as the wing, bag and cod-end part was 43%, 45% and 12%. However, the resistance of each part divided area of the part, calculated the resistance of per unit area, wing and bag part were not big difference each other, while the resistance of cod-end part was very large.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.296-302
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• 2014

The foliage of variegated Solomon's seal is excellent in cut flower arrangements. However, it has a restricted marketing period because the harvesting is limited in spring and summer. The increased interest requires the year-round production, thus techniques for dormancy breaking and forcing without low temperature treatment is needed. Therefore, experiments were conducted to d etermine whether gibberellic acid (GA) could break dormancy in variegated Solomon's seal. Thes prouting of dormant bud did not occur throughout the experiment when $GA_3$ $400mg{\cdot}L^{-1}$ was applied to dormant rhizomes as a soil drench. However, when plants were treated with a GA drench after scratch with razor blade or were given direct injection of GA, percent sprouting was increased up to 100 or 83.3%, respectively. However, because treatments with razor or syringe may damage internal organs, we tested another method, scarifying the rhizomes with sodium hypochlorite (NaOCl). Rhizome scarification with 4% NaOCl for 6 or 24 hours followed by drench of $GA_3$ $400mg{\cdot}L^{-1}$ increased the dormancy breaking percentage to 70 or 86.7%, respectively. Moreover, scarified and GA-treated rhizomes produced more leaves than untreated or GA-soil drenched plants in the glasshouse. These results showed the possibility of year-round production of variegated Solomon's seal foliage with rhizome scarification and GA treatments.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.5
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• pp.493-500
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• 2012

The previous geoid model developed in early 2000s shows 14cm level of precision due to the problems on distribution, and quality of the land gravity and GPS/Leveling data. From 2007, the new land and airborne gravity data as well as GPS/Leveling data having high quality and regular distribution has been obtained. In 2011, a new gravimetric geoid model has been constructed with precision of 5.29cm which was improved about 27% comparing to the previous model. However, much more land gravity data has been collected at the control point, bench marks and triangulation points since 2010. Also, GPS/Leveling data having 10km spacing over whole country has been obtained through the project which is for the construction of new control points. In this study, new gravimetric geoid has been calculated based on the all available gravity data up to present. The geoid height shows the range from 18.05m to 32.70m over whole country and its precision is 5.76cm. The degree of fit and precision of hybrid geoid model are 3.60cm and 4.06cm, respectively. At the end, 3.35cm of the relative precision in 15km baseline has been calculated to confirm its practical usage. Especially, it has been founded that regional bias occurred at the Kangwon and coastal area due to problems on the leveling data. Also, some inland points show inconsistent large difference which needs to be verified by analyzing the unified control points results.

• Korean Journal of Community Nutrition
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• v.20 no.2
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• pp.109-119
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• 2015

Objectives: The purpose of this study was to compare and analyze the results of salty taste assessment, dietary attitudes, and dietary behaviors among adult and senior women by region and by age. The results generated from this was expected to provide fundamental data for implementing a nationwide salt reduction education program. Methods: The salty taste assessment tool was applied to 4,064 subjects from 15 areas in Korea. Also, a survey of dietary attitude and dietary behavior related to salt intake was conducted for all subjects participated in this study. Results: The salty taste assessment scores by region and by age were the lowest in capital (p < 0.01) and was highest among the 70+ year age group (p < 0.01). The dietary attitude scores and dietary behavior scores showed that Gyeongsang was the highest (p < 0.001) and the capital was the lowest. The dietary attitude scores were highest at 20&30's followed by 40's and 70's group (p < 0.001). Dietary behavior scores showed that 20's~30's and 40's groups were higher than the other age groups (p < 0.001). The score of 'I like kimchi' was $3.46{\pm}0.88$, which was the highest among 10 dietary behavior questions. The score of 'I eat a lot of kimchi' was $3.30{\pm}0.90$, which was the highest among 10 dietary behavior questions related to salt intake. The scores of salty taste assessment had significant positive correlations between the scores of dietary attitude (p < 0.001), dietary behavior (p < 0.001) and self-awareness (p < 0.001). Conclusions: Based on the results of salty taste assessment, we observed a tendency that older people and regions except the capital had higher preference for salty taste. Our results suggested the necessity for a nationwide salty reduction education program tailored for regions and for different age groups.

• Horticultural Science & Technology
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• v.16 no.4
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• pp.520-524
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• 1998

This study was carried out to investigate the effect of thidiazuron(TDZ) on callus and shoot primordia formation, to determine the most optimum multiple shoot induction medium, and to obtain the plantlets on solid medium via shoot organogenesis. TDZ 0.01 mg/L in MS medium was most effective on callus formation, and BA 0.1 mg/L was most effective on shoot growth, while TDZ 0.01 mg/L was most effective on callus formation. TDZ 0.001 mg/L was most effective in shoot primordia formation. Shoot tips were cultured with TDZ 0.01 mg/L for 8 weeks and induced callus was transferred to regeneration medium containing TDZ 0.001 mg/L. After 4 weeks induced shoot primordia were resubcultured at growth regulator-free medium for 4 weeks. The induced multiple shoots rooted more efficiently at NAA 1.0, 5.0 mg/L, or IBA 5.0 mg/L.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.16 no.1
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• pp.17-22
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• 1980

Two plied twine, of which yarn is cored by abacca fibers and wrapped by polyethylen fibers, has been used for the material to web the wing net in the anchovy boat seine. This conventional twine revealed the disadvantage of which tensile strength goes from bad to worse. To improve the disadvantage, authors developed the new twine which is plied with three yarns, each yarn is cored by polyvinyliden chloride fibers and wrapped by polyethylen fibers. To compare the physical properties of the two kinds of twine, some factors are valued and the following results are found. 1. The conventional twine shrinks 4 to 7 percent when it was soaked in fresh water for 24 hours, whereas the improved one shrinks little. 2. The specific gravity of the conventional twine is valued 1. 04 to 1. 025 after soaking the twine in fresh water for 24 hours, in spite of including abacca to make the gravity heavier than that of sea water, whereas the improved ones are valued 1. 06 to 1. 09 without soaking. 3. The stiffness of the two kinds of twine differs little. 4. The breaking strength and the elastic recovery of the improved twine are greater than the conventional one. 5. Mesh size of the actual fishing net, webbed by the improved twine and employed in commercial fishing for 6 months, varied little.

• Journal of the Korean Geotechnical Society
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• v.33 no.12
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• pp.81-92
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• 2017

According to the revision of the Housing Act in 2013, it has been possible to carry out an apartment remodeling project involving two to three floor vertical extension. The remodeling project with vertical extension requires foundation reinforcement because structural safety due to additional load and enhanced seismic criteria must be met. In this case, structural analysis is performed to analyze the load distributed to existing PC pile and reinforced additional pile. The vertical stiffness ($K_v$) of the pile is required for structural analysis, but the research on the 20~30 year old PC pile stiffness is very limited. In this paper, the stiffness of the PC pile in accordance with the change of diameter and length was analyzed by examining the results of 38 field pile load tests performed during the construction of the apartments in the 1990's. As a result of the analysis, the pile stiffness decreases with the increase of the length-diameter ratio (L/D). In addition, the results of on-site pile load test are compared with the coefficient 'a' for estimating pile stiffness proposed in Korea Highway Bridge Design Standard (2008) and the Pile Foundation Design Guideline of Korea Railroad Corporation (2012). It shows that 'a' obtained through the estimation of the literature is very similar to the field test results in the range of 10