• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.49-52
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• 2013

Seed coat of hairy vetch is very thick and hard, and difficult to absorb water during germination. It requires much time that cotyledon comes out from seed coat. Therefore this experiment was carried out to increase the germination rate by enhancing water absorption through water-soaking of seed, chemical scarification by sulfuric acid, and mechanical scarification on seed coat. Water-soaking for 5 hours seemed to be highly effective in enhancing germination rate. Although not significant, water-soaking resulted in increase of germination rate by 9%. Effect of soaking temperature was not significant, but early germination rate was increased to be 5.0%, 31.7% and 48.3% at $10^{\circ}C$, $20^{\circ}C$ and $30^{\circ}C$, respectively. Mechanical scarification of seed coat led to a germination rate of 97% whereas intact seed showed that of 65%. Chemical scarification by sulfuric acid for 10min, 20min and 30min resulted in a germination rate of 76.7%, 74.7% and 96.0% respectively. It is clear that scarification increased germination rate.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.254-259
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• 1997

The measurement of surface roughness and waviness by means of noncontact method is an important area to be developed for GAC(Geometrical Adaptive Control) system. This paper deal with the design of noncontact in-process measurement system which measures the surface roughness and waviness during cylindrical grinding. This measuring system is simple and the apparatus proposed is composed of a laser unit, photodetector and optical system. During operation, the surface of a workpiece is continuously scanned by a laser beam. This method makes it possible to detect the surface roughness and waviness along the feed direction by control the spot diameter of laser beam. The experimental results show that the presence of chattering, loading and glazing can be detected sensitively along the feed directions.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.6
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• pp.132-140
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• 1998

Recently, precision machining technology has been developed continuously in order to make high productivity and quality assurance of the precision parts of several industrial fields. Waviness may occur on the surface of the machined parts due to the table motion error and the dynamic cutting mechanism between the tool and the workpiece. The waviness may fall off the form accuracy of the precision machine parts. In the research, a micro cutting device with piezoelectric actuator has been developed to control precise depth of cut and compensate the waviness on the surface of the workpiece. Experiments have been carried out in the precision lathe. The characteristics of the surface profile and cause of the waviness profile have been analyzed and waviness profiles of some cause have been compared with those of experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1573-1574
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• 2011

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.108-117
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• 2011

Old train carriages have been used to create artificial reefs (AR) as part of programs to enhance ocean fisheries and recreational resources. This study conducted hydraulic modeling experiments to estimate the structural stability of a train carriage AR. By applying fixed- and movable-bed conditions and Froude similitude, theoretical and hydraulic experiments revealed major design forces(e.g., water waves and currents). The results of this study showed that some dimensionless design parameters (e.g., surf similarity parameters, water particle velocity, scouring, and deposition) also affect the stability of an AR under various wave and current field conditions. In the fixed-bed condition, movement of the AR occurred when dimensionless water particle velocity based on the surf similarity parameter was larger than about 0.32. In the moveable-bed condition, the settlement depth (field values) of the AR ranged from 6 to 30 cm. The results indicated that characteristics of the sediment/bed condition and the direction of external forces acting on an AR should be considered when selecting AR sites.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.5
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• pp.725-734
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• 2010

This study conducted hydraulic testing to assess the stability of two types of pyramid-shaped artificial reefs (ARs) constructed to promote the growth of shellfish and seaweed. Previous theoretical and hydraulic experimental studies have clearly demonstrated Froude similitude. The results of this study revealed that some dimensionless design parameters affected the stability of both types of artificial reefs under various wave and current field conditions (e.g., surf similarity parameters, water particle velocity, wave pressure). In the fixed bed condition, the dimensionless water particle velocity based on the surf similarity parameter was large (about 0.4), and in the moveable bed condition, the relative water depth based on the dimensionless wave pressure was low (about 0.11). In addition, horizontal wave pressure and uplift pressure varied by relative water depth, demonstrating the tendency for wave pressure to decrease linearly with increased relative depth. These findings indicate that the development of more stable design technology forartificial reefs should be based on long-term data and additional study of sliding due to wave action. The findings also highlight the importance of hydraulic experiments in solving problems that have emerged in the design and construction of artificial reefs.

• Korean Journal of Plant Taxonomy
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• v.41 no.1
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• pp.35-46
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• 2011

The seed morphology of 22 taxa (12 genera) of Solanaceae in Korea was studied by stereo and scanning electron microscopy, and a detailed description of seed morphological features for all examined taxa is provided. The color of the seed is yellow to black, and the shape is reniform to circular. Its size is 0.56-4.29 mm in length and 0.38-3.20 mm in width. The largest sample was found in Datural metel, while the smallest was in Petunia hybrida. Three different surface types (verrucate, verrucate-reticulate, and reticulate) were recognized in the studied taxa. The top of the anticlinal wall produces appendages known as 'fibrils'. This projection of anticlinal wall was found to be specific to the genus Solanum (S. japonense, S. lyratum, and S. lycopersicum). The morphological features (seed shape, size, color, hilum shape, surface type, and fibrils) of the family Solanaceae in Korea are described and their systematic implications are briefly discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.297-300
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• 2008

Friction coefficients of the prestressing tendon are the basic information required to control the prestressing force introduced to PSC structure during jacking. However, the friction coefficients show considerable differences depending on the specifications, causing much confusion to designers. In this study, a procedure is proposed that can be used to estimate the wobble and curvature friction coefficients from field data and classical theory related to the friction. The procedure is applied to two PSC girder bridges with various tendon profiles. The resulting values are compared with those presented in some specifications and assumed in jacking. The resulting wobble friction coefficients are not as small as those presented in AASHTO specifications but are more or less similar to the lower limit of domestic standards, while the curvature friction coefficients approach or slightly exceed the upper limit of the same standards.

• Archives of design research
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• v.19 no.5 s.67
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• pp.129-138
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• 2006

It is expected that the typical lifestyle of the future will be transformed into an opulent and comfortable existence as the quality of life improves due to the increase in household income and reduction in working hours. In the meantime, as the standard of living becomes increasingly more comfortable and plentiful, the toll on physical health becomes magnified as a result of obesity and insufficient exercise caused by super nutrition and change in labor conditions (from physical labor to mental labor). This has instigated a deep awareness in fitness on the part of many people, forcing them to recognize the significance of daily exercise and physical activity. The high annual growth rate in the fitness and athletic apparatus market, which is more than 20%, is attributed to this phenomenon. The Elliptical Cross Trainer(ECT), which has drawn wide attention recently, is a non-impact athletic apparatus that not only promotes exercise of the upper body parts in such sports as skiing but also the exercise of lower parts of the body on a treadmill. It is a type of cross training athletic gear that has been developed for aerobic exercise throughout the entire body. It has already formed a market as big as that of the treadmill in Europe, America, etc. Recently, its demand is growing sharply in the Korean markets as well as those in Northeast Asian countries, Despite such demand increase and expansion, since most of the expensive ECTs are exclusively supplied by suppliers in only a few advanced countries, localization of the ECT is urgently required in order to enhance competitiveness of Korean manufacturers and to expand the market. This paper introduces the process and results of a design-engineering cooperative study that was peformed for the development of the ECT.

• Archives of design research
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• v.19 no.5 s.67
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• pp.85-94
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• 2006

In the 2000s, character animation technique is used at domestic TV character animation ads of diverse items displaying new character patterns and expression techniques of a high level. This study intends to identify the characteristics of TV character animation ads based ell character aesthetic theory and advertising rhetoric theory, and based on these findings, analyze trend and stream of expression in TV character animation ads by examining and classifying advertisements released in the past four years by items, character patterns and expression techniques. The results showed that TV character animation ads have been concentrated on confectionery, beverages and foods in the past, but the items have been diversified through the years. With reference to character patterns, personal and animal characters had made the main pattern, but recently product, virtual and composite characters are on the increase. In expression techniques, cell animation technique was found to be the most frequently used technique, which was followed by full-3D, cell and live action, cell and 3D and the clay animation technique. A trend like this suggests that TV character animation advertising items will continue to increase in line with the participation level of targets. In the meantime, personal and animal characters will continue to make the leading character pattern, while virtual and composite character patterns emerge in new forms. In expression techniques, live action combined with 30 technique and techniques using new expression materials will appear with cell animation technique as a central figure. As a whole, Korean character animation advertisement is expected to keep on growing to a new dimension in the aspect of items, character patterns and expression technique.