• Korean Journal of Medicinal Crop Science
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• v.25 no.6
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• pp.381-388
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• 2017

Background: This study was conducted to acquire basic information on the phenotypic and genotypic characteristics of the germplasm of Panax ginseng C. A. Meyer collected from China and Korea, and identify the variations that can be utilized in ginseng breeding programs. Methods and Results: Quantitative parameters were evaluated, and used to compare and analyze on genetic polymorphisms in the germplasm. The genetic characteristics and classifications were compared and analyzed for each character. Stem length followed a normal frequency distribution ranging from 15.5 cm to 40.5 cm, with showing approximately 40% having a stem length of 20 - 30 mm. Stem diameters ranged from 2.7 mm to 11.3 mm. Stem number per plant ranged from 1 to 3; approximately 50% had a single stem, and 45% had two stems. A non-normal frequency distribution was observed for petiole number, with approximately 60% of the germplasm having 3 - 5 petioles. Petiole length exhibited a normal frequency distribution, raging from 4.5 to 10.6. Petiole angle in the germplasm ranged from $28^{\circ}$ to $89^{\circ}$ and seedstalk length ranged from 5.6 cm to 27.3 cm. Conclusions: The genetic polymorphisms identified by complete linkage clustering based on the quantitative characteristics of Panax ginseng C. A. Meyer collected from Korea and China were classified to 6 groups, namely I, II, III, IV, V, and VI with frequencies of 6.7%, 20.0%, 31.7%, 8.3%, 6.7%, and 26.7%, respectively.

• Journal of Korean Society of Forest Science
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• v.94 no.5 s.162
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• pp.313-320
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• 2005

This study was performed in a 38-year-old Mongolian pine (Pinus sylvestris L. var. mongolica Litvin) plantation in northeast China. Data were collected from 5 sample trees with different canopy position ranging in DBH from 14.6 cm to 23.8 cm. Sawn speciments that included the biggest knot were taken from the stem below the living crown. Number and distribution of knots per whorl below the living crown were studied by relative height below living crown (RHBC). A linear model expressed as function of whorl age (AGE), whorl height ($H_k$) and the stem diameter at which the whorl was located ($D_k$) was developed to predict the knot diameter and angle. The number of annual rings in four periods and the width of respective zone alone stem were used as dependant variables to analyze the knot develop phases. In average, the number of years from branch birth to ceased forming rings was 7.8, the branches remained alive for 4.2 years without forming annual rings, and branches were occluded 14.4 years after their death. These results can provide abundance branch and knot information so as to describe current and past tree growth dynamic of Mongolian pine plantation.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.5
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• pp.446-456
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• 2007

Numerical analyses of stem waves, the interaction between incident and reflected waves of obliquely incident regular waves along a vertical wall in a constant water depth, are presented. For the numerical model of the analysis, the two-layer Boussinesq equations developed by Lynett and Liu(2004a,b) are employed. Numerical results are compared with both laboratory measurements and those obtained using parabolic approximation model. The overall comparisons between the results from the two numerical models and the experiments are good. However, the two-layer Boussinesq model is more accurate than the parabolic approximation model as the angle of incident waves increases. In particular, the higher harmonic generation due to the wave nonlinearity is captured only in the Boussinesq model.

• Journal of Biosystems Engineering
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• v.21 no.3
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• pp.315-324
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• 1996

This study was one of a series of studies on application of machine vision and image processing to extract the geometrical features of plants and to analyze plant growth. Several algorithms were developed to measure morphological properties of plants and describing the growth development of in-situ lettuce(Lactuca sativa L.). Canopy, centroid, leaf density and fractal dimension of plant were measured from a top viewed binary image. It was capable of identifying plants by a thinning top viewed image. Overlapping the thinning side viewed image with a side viewed binary image of plant was very effective to auto-detect meaningful nodes associated with canopy components such as stem, branch, petiole and leaf. And, plant height, stem diameter, number and angle of branches, and internode length and so on were analyzed by using meaningful nodes extracted from overlapped side viewed images. Canopy, leaf density and fractal dimension showed high relation with fresh weight or growth pattern of in-situ lettuces. It was concluded that machine vision system and image processing techniques are very useful in extracting geometrical features and monitoring plant growth, although interactive methods, for some applications, were required.

• Transactions of Materials Processing
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• v.15 no.3 s.84
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• pp.226-231
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• 2006

The fuel injector is a pa.1 that controls the fuel supply of automotive engine. The housing of the fuel injector supports the rod, the needle valve and the solenoid. In this study, the rigid-plastic FE-analysis by using the design of experiments (DOE) and the response surface methodology (RSM) has been performed to produce the product reducing the under-fill and the maximum effective strain. From the results of DOE, the stem of counter punch and the face angle of punch at the $1^{st}$ process, and the stem of punch at the $2^{nd}$ process were determined as the significant design variables far each response such as the upper under-fill, lower under-fill and the maximum effective strain. From the results of RSM, the optimal values of the design variables have been also determined by simultaneously considering the responses.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.322-327
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• 2019

This study was conducted to improve the performance of automatic grafting robot using image recognition technique. The stem diameters of tomatoes and cucumber at the time of grafting were $2.5{\pm}0.3mm$ and $2.2{\pm}0.2mm$ for scions and $3.1{\pm}0.7mm$ and $3.6{\pm}0.3mm$ for rootstocks, respectively. The grafting failure was occurred when the different height between scions and rootstocks were over 4 mm and below 2 mm due to the small contact area of both cutting surface. Therefore, it was found that the height difference at the cutting surface of 3 mm is appropriate. This study also found that grafting failure was occurred when the stem diameters of both scions and rootstocks were thin. Therefore, it was suggested to use at least one stem with thicker than the average stem diameter. Field survey on the cutting angle of stems by hand were ranged from 13 to 55 degree for scions and 15 to 67 degree for rootstocks, respectively, which indicates that this could cause the grafting failure problem. However, the automatic grafting robot developed in this study rotates the seedlings 90 degree and then the stems are cut using a cutting blade. The control part of robot use all images taken from grafting process to determine the distance between a center of both ends of stem and a gripper center and then control the rotation angle of a gripper. Overall, this study found that The performance of automatic grafting robot using image recognition technique was superior with the grafting success rates of cucumber and tomato as $96{\pm}3.2%$ and $95{\pm}4%$, respectively.

• Journal of Biosystems Engineering
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• v.10 no.1
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• pp.13-23
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• 1985

Spraying method from the paddy-field levee is known to give insufficient penetration of the spray droplets to the rice stem of the densely grown plants, which is generally encountered at the last stage of rice growth. This study was intended to investigate the spraying system to solve this existing problem. As an approach, it was attempted to develop the boom-with-nozzle, between-the-row application system. Several types of nozzles and their different arrangements in the boom were tested in the field to measure the penetration-reaching distance and the uniformity of spray droplet distribution. The results of the study are summarized as follows: 1. Field experiments by the spraying method from the paddy-field levee showed to have practically no penetration of the spray droplets to the portion of the plant stem with the normal flow volume generally applied and thus need for improving present spraying method. 2. It was found that, considering both the uniformity of the spray droplet distribution and performance rate, the most efficient type of nozzle in the between-the-row boom-type spraying system was one that has core-insert hollow-cone with some clearance between the cone and tip. 3. When tested by applying the spraying method of between-the-row, the nozzle pressure did not affect the uniformity of spray droplet distribution. However, the nozzle pressure had a positive effect on the penetrating-reaching distance of the facing side of the rice stem and did not affect much on that of the opposite face of the stem. It was also found that the maximum pressure to affect the penetration-reaching distance was about $10kg/cm^2$. 4. The uniformity of the spray droplet distribution in the between-the-row system was greatly affected by the height and orientation of the nozzles in the boom. Based on experimental work for the different type of the boom-with-nozzle arrangements, it is recommended that the position of nozzle is set at about 0.45 m above the ground and two nozzles in the boom are oriented to be faced with each other with some angle such that the droplet stream from the nozzle would not directly face with each other.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.244-248
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• 2000

It was investigated and analized on the construction and hull form for the ordinary fishing boat of south coast in Korea, and then analogized on the shipbuilding technology of fishing boat and fishing type around 1900 by B-spline form parameter method. The results obtained can be summarize as follows : (1) It was known that the boats used in this study have more narrow hull form than that of ancient fishing boats and their hull form was improved around 1900. (2) Keel was composed of bar keel with angle cross section. The stem corner have a material of bar stem and makes a sharp pointed stem. (3) Shell plate was jointed by the rabbetted clinker joint method. (4) It was investigated that anchovy drag net fishing boat has high L/B, L/D, B/D value as compared with drift gill net fishing boat. (5) Two boats have a good stability and particularly anchovy drag net fishing boat have a better stability value in comparison to the drift gill net fishing boat.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.11-17
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• 2015

The study was conducted to investigate the effect of rootstock on growth and early yield of stenting-propagated cut roses (Rosa hybrida Hort.) 'Pink Aurora' and 'Yellow King'. The scions, prepared as single-node cuttings, each with a five-leaflet leaf, were grafted onto cuttings of Rosa indica 'Major', Rosa multiflora 'Chille Wonye No. 1', Rosa multiflora 'K-1', or Rosa multiflora 'Burr' as the rootstock. The rootstock cuttings were removed of all leaves and buds before grafting. The base of scion and the top of rootstock were held together and simultaneously cut at a $45^{\circ}$ angle for ease of grafting. Scion-rootstock unions were stuck in rockwool cubes and placed on a misted glasshouse bench for rooting before being transplanted into a rockwool slabs for cultivation. Rooting was the greatest in the 'Pink Aurora' and 'Yellow King' grafted on the rootstock Rosa indica 'Major'. In 'Pink Aurora', stem length, stem diameter, five-leaflet leaves per stem, and stem fresh weight of the harvested cut flowers were not affected by the rootstock. The greatest total yield of 'Pink Aurora' was obtained in plants grafted onto the Rosa indica 'Major' rootstock. Overall growth of 'Yellow King' was the greatest in plants grafted onto Rosa multiflora 'Burr' rootstock, although total yield was not affected by the rootstock. These results suggest that Rosa indica 'Major' is the most effective rootstock not only for rooting, but also for early yield and growth for stenting propagation of these cut roses.

• Journal of the Korean Society of Tobacco Science
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• v.5 no.2
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• pp.25-32
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• 1983

To obtain basic information on the breeding of burley tobacco, classification of 41 varieties was carried out by using the cluster analysis of correlation coefficients and taxonomic distance based on twenty-one agromonic characters. Eight characters, such as days to flowering, length of flower axis, internode length, leaf length, yield, leaf angle to stem, vein angle to midrib and plant height, were useful in monothetic classification. Forty-one varieties were classified into four groups (I, II, III and IV) with weighted variable group method (WVGM ) and weighted jai. group method(WPGM), whereas the results classification of 33 varieties among them by WVGM were coincident with the results by WPGM. As for the characteristics of each group, group I related to late maturity, tall height and high yield, group II related to intermediate maturity, tall height and low yield, group 19 related to early maturity, intermediate height and low yield, and group W related to early maturity, short height and intermediate yield.