• Journal of Sericultural and Entomological Science
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• v.36 no.2
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• pp.102-109
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• 1994

Profitability was analysed in the fields of various planting densities from 1,666 trees/10a to 4,166 with mulberry grafts or conventional saplings under the consideration of leaf yield and quality. Leaf yield per tree decreased with the higher planting densities. Seasonal and total leaf yield per area, however, increased by 20 to 63% as a mean for 3 years in the densities of 2,083~4,166 trees per 10a than in the conventional density of 1,666 trees per 10a. The increase in leaf yield per area was not so high in the densities over 2,083. Leaf yield in the sapling plots was a little higher than that in the graft plots. Topping of shoot tip affected neither on the branch length nor on yield. Yield was higher in the planting spacing with single raws than in that with double raws. Quality of leaves in the densities from 2,083 to 3,333 trees per 10a was relatively good judged based on the results of the pupation rate and cocoon yield and quality.

• Journal of Korean Neurosurgical Society
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• v.30 no.1
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• pp.41-46
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• 2001

Objective : The exact position of the lesion during the pallidotomy is critical to obtain the clinical improvement of parkinson's disease without damage to surrounding structure. Ventriculogrphy, CT(computed tomograpy) or MRI(magnetic resonance imaging) have been used to determine the initial coordinates of stereotactic target for pallidotomy. The goal of this study was to determine whether microelectrode recording significantly improves the neurophysiologic localization of the target obtained from MRI. Methods : Twenty patients were studied. They underwent a unilateral pallidotomy. Leksell frame was applied and T1 axial images parallel to the AC-PC(anterior commissure-posterior commissure) plane using a 1.5 Tesla MRI with 3mm slice thickness were obtained. Anteroposterior coordinate of target was chosen at 2mm in front of the midcommissural point and lateral coordinate between 19 and 22mm from the midline. The vertical coordinate was calculated on coronal slice using a fast spin echo inversion recovery sequence(FSEIR) related to the position of the choroidal fissure and ranged over 4-5mm below the AC-PC plane. Confirmation of the anatomical target was done on axial slices using the same FSEIR sequence . Microrecording was done at the pallidum contralateral to the symptomatic side using an electrode with a tip diameter of $1{{\mu}m}$ diameter tip and 1.1-1.4 mOhm impedance at 1000Hz. Electrophysiologic localization of the target was also confirmed intraoperatively by macrostimulation. Results : Microrecording techniques were reliable to define the transition from the base of the pallidum which was characterized by the disappearance of spike activity and by the change of the audible background activity. Signals from high amplitude neurons firing at 200-400Hz were recorded in the pallidal base. X, Y and Z coordinates of target obtained from the MRI were within 1mm from the X, Y, Z coordinates obtained with microrecording in 16 patients (80%), 15 patients(75%), 10 patients(50%) respectively. The difference of Y coordinate between on MRI and on microrecording was 4mm in only one patient. Conclusion : The MRI was accurate to localize the target within 1mm of the error from microrecording target in 70% of the patients. 4mm discrepancy was observed only once. We conclude that MRI alone can be used to determine the target for pallidotomy in most patients. However, microrecording technique can still be extremely valuable in patents with aberrant anatomy or unusual MRI coordinates. We also consider physiologic confirmation of the target using macrostimulation to be mandatory in all cases.

• Korean Journal of Medicinal Crop Science
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• v.7 no.2
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• pp.94-100
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• 1999

To establish the mass propagation system of Lavandula spica cv. Marino, shoot tip, node, internode and leaf segment cultures were carried out. RAPD was applied to detect the somaclonal variation. Callus induction was very high in the medium supplemented with 1 mg/l 2.4-D, 2 mg/l NAA. especially and combined with 0.05 mg/l BAP from leaves. Shoot formation was high with $2{\sim}4\;mg/l$ BAP or 4 mg/l BAP + 0.2 mg/l NAA from shoot tip. Shoot proliferation was 9.1 times in the $B_{5}$ medium with 0.5 mg/l BAP and 0.01 mg/l NAA. Root formation was improved in NAA, which was the concentration of 0.1 to 1 mg/l and 1 mg/l IAA. Nursery survival rate was enhanced over 90% and growth was looked good in the acclimation soil consisting of peatmoss : vermiculite : perlite (1:1:1, v:v:v). Randomly amplified polymorphic DNA banding patterns based on polymerase chain reaction (PCR) were used to assess the genetic variation in plants regenerated from in vitro culture.

• Korean Journal of Plant Tissue Culture
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• v.27 no.1
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• pp.63-69
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• 2000

In order to establish a micropropagation system for buffalo gourd (Cucurbita foetidissima ) and common milkweed (Asclepias syriaca), the effects of several plant growth regulators and culture temperature on shoot multiplication and rooting were investigated. In buffalo gourd, the greatest number of shoot from shoot tip culture and well growth of formed shoot were obtained on the MIS medium supplemented with 1.0 mg/L BA and 0.3 or 0.6 mg/L IAA. Whereas kinetin and 2iP were not effective for shoot multiplication in vitro. It was found that 22$^{\circ}C$ and $25^{\circ}C$ were suitable for shoot multiplication. Roots were easily formed by the addition of auxins, especially 1.0 or 2.0 mg/L IBA and 2.0 mg/L IAA. Over 90% of plants survived successfully after being transferred into the field. In common milkweed, BA was more effective than kinetin or 2iP for its micropropagation in vitro. The increased shoot weight and number of nodes per shoot were obtained on the medium containing 3.0 mg/L BA and 0.3 or 0.6 mg/L IAA. But 2iP promoted the shoot elongation. In addition. common milkweed was sensitive to culture temperature in vitro. Temperature around 22$^{\circ}C$ was favorable for shoot multiplication and growth, whereas temperature higher than $25^{\circ}C$ usually reduced the rate of shoot survival rate.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.161-166
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• 1994

Since garlics (Allium sativum L.) are propagated through cloves, infection by virus or other pathogens may become severe problem if not using high quality seed bulbs every year resulting in the reduction of yield and bulb quality, In order to solve this problem, the establishment of virus-free bulb production and its supply system have been required because no chemicals were found to eliminate viruses from seed bulbs. This experiment was conducted to develop an effective production technique of high quality seed bulbs using shoot-tip culture. Over 90% of shoot-tips explanted on January L 1990 were survived at constant temperature of either 20, 24 or 28$^{\circ}C$, wheres 88% at alternate temperature (28/20$^{\circ}C$). The growth of shoot and root was most vigorous at constant 24$^{\circ}C$, and least at alternate temperature (28/20$^{\circ}C$) condition. When shoot-tips were explanted June 21 to August 1,1991, survival and growth of shoot-tips was most vigorous on MS medium supplymented with 0.1 mg/L NAA and 2 mg/L kinetin and least 1 mg/L Gh$_3$. The shoot-tips taken from the seed bulbs stored at 4$^{\circ}C$ for 15 to 60 days were placed on MS medium, shoot growth and in vitro bulblet formation increased slightly as affected by the increase of told treatment period at 4$^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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• pp.897-905
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• 2014

The foliage of sweet potato [Impomoea batatas (L.) Lam] is an excellent source of food material due to the functional components of polyphenol and carotenoid. In this study, the lightness (L-value), polyphenol contents, and DPPH radical scavenging activity of the foliage of Shinwhangmi, Hayanmi and Suioh cultivars harvested after different cultivation periods (60, 90 and 120 days after planting) and according to tip locations (1st~5th, 6th~10th, 11th~15th tips) were investigated. As a result, Shinwhangmi showed a lower lightness value (60 days after planting and 1st~5th tips). The longer the cultivation periods and the closer the tips, the higher the contents of polyphenol and DPPH radical scavenging activity were in lyophilized foliage of Shinwhangmi, Hayanmi and Suioh. In the 1st~10th tip of Shinwhangmi, Hayanmi and Suioh cultivated for 90 days and dried by 2 step hot-air (1st: $70^{\circ}C$ for 8 hr, 2nd: $80^{\circ}C$ for 4 hr), the polyphenol and ${\beta}$-carotenoid contents were 5.0, 3.9 and 4.0 mg/g and 75.6, 71.6 and 63.1 mg/g, respectively. The DPPH radical scavenging activities and ABTS radical scavenging activities ($EC_{50}$) were 0.29, 0.36 and 0.33 mg and 0.12, 0.15 and 0.11 mg, respectively. These antioxidative activities were over two times stronger than spinach.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.38-43
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• 1999

Over 2,000 ha of rice fields in the western and southern coastal region of Korea were flooded with sea water during the spring tide, on August 19-21, 1997, and the rice plant at heading stage was injured. The field surveys were undertaken at the sea water flooded paddy fields in Chonbuk Province, to identify the injury symptoms and rice yield damage subjected to different flooding condition and desalinization methods. Five days after sea water flooding at heading stage, the flag leaves of rice plants flooded with 30 ㎝ deep sea water withered from the tip, the withering progressed to the lower leaves in deeper flooding. The spikelets were spotted black and discolored from the tip at 50 ㎝ deep flooded rice, and some panicles changed to white at 80 ㎝ deep flooded rice. Most of the rice leaves submerged completely for an hour were withered and most of panicles changed to white. The milled rice yield, percentage of ripened grain, and 1000 grain weight of flooded rice decreased with deeper flooding water, higher water salinity and longer flooding time. Even under the same flooding conditions, the damage of rice yield varied with the growth stage: heading stage>dough stage>booting stage. Rice yield damage was less in the fields on the upper riverside than those of the fields on the estuary and seaside, because of lower water salinity. In a flooded field, the rice yield damages were reduced as the distance increased from the levees where the sea water inflowed and increased as the distance increased from the fresh water irrigation gate. The desalinization treatments consisting of frequent exchange of irrigation water and spraying with fresh water soon after flooding effectively reduced the rice yield damage.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.3
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• pp.200-213
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• 1993

A model experiment on a midwater rope trawl net which is used in the North Pacific to catch alaska pollack is carried out in the circulating tank to examine the basic efficiency of the net. The prototype is the net used by M/S Hanil(1, 179GT, 2, 700PS), a Korean trawler. The model net was made according to the Tauti's Similarity Law of Fishing Gear in 1/100 scale by considering the condition of the tank. To measure the basic efficiency of the standard model net, the vertical opening and width between some points marked on the net were measured, and the hydrodynamic resistance were determined. Then the constructive conditions of the net were varied as follows and the factors were measured again to compare the efficiency of those nets with that of the standard net(A-1 type) front weight multiplied 1.5 times: A-2 type. buoyancy and depressing force multiplied 1.7 times: A-3 type. front weight multiplied 1.5 times on A-3 type: A-4 type. depressors rigged at ground rope: B type. cod-end stuffed with cashmylon wad: C type. The results obtained can be summarized as follows: 1. The vertical opening at the center of head rope was steeply decreased with the flow velocity increasing and the vertical opening H(m) can be expressed in H=1.2v super(-1.2)(v : flow velocity in m/sec). The width of the net varied a little when the flow velocity was over 0.4m/sec, and the width of net mouth showed about 37% of the distance between the fore tips of net pendant. The shape of net mouth was almost a circle at 0.2m/sec and then steeply flatted elliptically with the flow velocity increasing and the area of mouth S(m super(2)) can be expressed in S=(1.65-2.3v)$\times$10 super(-2). The hydrodynamic resistance of the net increased almost linearly with the flow velocity increasing and the resistance R(kg) can be expressed in R=3.2$\times$d/l$\times$abv. where d/l denotes the mean of d(diameter of netting twine) and l(length of a leg in a mesh) from wing tip to the end of bag-net except cod-end on the side pannel, and a denotes the strectched circumference of the net at the fore end of a meshed part and b the stretched length of the whole net from wing tip to the end of cod-end. 2. In the condition-varied nets, the vertical opening of head rope showed some increase in every type net except the C type, and the increase showed the greatest in the B type by 30~54%, whereas it showed decrease in the C type by 5~10%. Variation of the area of net mouth showed almost the same tendency as the vertical opening and the increase showed the greatest in the B type by 20%, whereas it showed decrease in the C type by 12%. Hydrodynamic resistance showed some increase in every type compared with the standard net, and the rate of increase indicated 5~10% in the A-2, A-3 and A-4 type, 22% in the B type and 3% in the C type.

• Korean Journal of Materials Research
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• v.10 no.4
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• pp.295-300
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• 2000

Uniform silicon tip arrays were fabricated using the reactive ion etching followed by the reoxidation sharpening, and the effect of Pd-coated layer on electron emission characteristics was studied. The electron emission from Si field emitter arrays(FEAs) was a little, but improved by removing surface oxide on the FEA, but pronounced drastically by coating a $100-{\AA}-thick$ Pd metal layer. The turn-on voltage in the Pd-coated Si FEAs was reduced by 30 V in comparison with that in uncoated ones. This results from the increase of surface roughness at the tip apex by the Pd coating on Si FEA, via the decrease of the apex radius at which electrons are emitting. The Pd-coated emitters showed superior operating stability over a wide current range to that of the uncoated ones. This suggests that Pd coating enhances the high temperature stability and the surface inertness Si FEA.

• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.731-743
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• 2018

This study was conducted to evaluate the effects of green manures and complemental fertilization with oil cake or liquid fertilizer on growth and nitrogen use efficiency of Chinese cabbage cultivated in organi systems. Field experiments were carried out at the National Institute of Agricultural Science in Suwon, South Korea from 2012 to 2014. Two green manure crops, Crotalaria and Hairy vetch, was cultivated in summer and in winter, respectively. The application methods of the green manure consisted of three tillage systems (overall tillage, partial tillage and no tillage). Oil cake and liquid fertilizer were used as complemental fertilizer. The results showed that when used as covering material in the upland soil without tillage, green manure fertilization was more effective in increasing growth and yield of Chinese cabbage than when incorporated into soil. It was possible to grow and harvest Chinese cabbage in the spring season by the application of hairy vetch as winter green manure. The higher yield of Chinese cabbage with green manure application was caused by the lower incidence rate of soft rot and tip-burn. The yield of the Chines cabbage that received green manure applications over two consecutive seasons followed by the supplemental fertilization with oil cake was similar to that of the conventional chemical fertilization. Following a single season green manure application in summer, however, the yield of cabbage was only about 70% of the conventional treatment. Green manure cultivation with additional liquid fertilization produced a yield similar to the conventional fertilization treatment, soil inorganic nitrogen concentration remained stable and the nitrogen use efficiency increased in the green manure applied soil. In conclusion, the organic cultivation of Chinese cabbage in the autumn season could be outperformed in the upland soil receiving two seasons (winter and summer) of green manure fertilization followed by the supplemental fertilization with liquid fertilizer.