• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.2
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• pp.114-124
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• 2014

For classifying fire damaged areas and analyzing burn severity of two large-fire areas damaged over 100 ha in 2011, three methods were employed utilized supervised classification, unsupervised classification and Normalized Difference Vegetation Index (NDVI). In this paper, the post-fire imageries of SPOT were used to compute the Maximum Likelihood (MLC), Minimum Distance (MIN), ISODATA, K-means, NDVI and to evaluate large-scale patterns of burn severity from 1 m to 5 m spatial resolutions. The result of the accuracy verification on burn severity from satellite images showed that average overall accuracy was 88.38 % and the Kappa coefficient was 0.8147. To compare the accuracy between burn severity and field survey at Uljin and Youngduk, two large fire sites were selected as study areas, and forty-four sampling plots were assigned in each study area for field survey. The burn severities of the study areas were estimated by analyzing burn severity (BS) classes from SPOT images taken one month after the occurrence of the fire. The applicability of composite burn index (CBI) was validated with a correlation analysis between field survey data and burn severity classified by SPOT5, and by their confusion matrix. The result showed that correlation between field survey data and BS by SPOT5 were closely correlated in both Uljin (r = -0.544 and p<0.01) and Youngduk (r = -0.616 and p<0.01). Thus, this result supported that the proposed burn severity analysis is an adequate method to measure burn severity of large fire areas in Korea.

• Journal of Technologic Dentistry
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• v.12 no.1
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• pp.23-45
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• 1990

This study aimed at inquiring into the basic theory on co-operative education, grasping and analyzing the present situation of the junior health college, the present condition of co-operative education and into problem. and seeking to find a solution to activate the co-operative edcation of the junior health colleges. For this purpose this study compared the co-operative education system in our country with that of foreign countries revolving around the related literature to co-operative education, analyzed it, and the pointed out its problem. And this study classified into the solution of establishing co-operative education system, the solution of consolidating the on-the-spot training system, the solution to activate the co-operative education of the junior health college. First this study suggested three methods as a part of establishing co-operative education system as below. 1. The need to set up the ideology concerning co-operative education. 2. The construction of the advisory committee for co-operative education. 3. The establishment of an agency for co-operative education. And this study suggested nine methods as the method of consolidating the on-the-spot training as below. 1. The execution of the basic research for the on-the-spot training. 2. The reorganization of the existing curriculum into the curriculum the industrial organization requires. 3. The establishing of the system in a closer cooperation with the industrial organization for the on-the-spot training. 4. The participation in solving commonly the problems of the industrial organization and in education. 5. The establishing of the guidance system assuming exclusive charge of the on-the-spot training. 6. The submission of the evaluation sheet for the on-the-spot training. 7. The extension of the period of the on-the-spot training and the reorganization of an educational system. 8. The persistent support for the on-the-spot training at the governmental dimension. 9. The securing of the educational dost spent on the on-the-spot training and the imposition of benefits on the industrial organization.

• Korean Journal of Weed Science
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• v.12 no.4
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• pp.368-373
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• 1992

The effect of alachlor treatment on protein synthesis was studied. Protein synthesis was inhibited by $1{\times}10^{-4}$ M and $1{\times}10^{-3}$M of alachlor 5.8% and 86.5%, respectively, while did not occur blow $1{\times}10^{-5}$M alachlor. Soluble protein of alachlor treated oat root tips was examined by polyacrylamide gel electrophoresis. The proteins extracted from oat root tips showed that they were made up of subunits blow 100 kd polypeptides by SDS-PAGE. As compared to control, high molecular proteins(above 47 kd) were inhibited of oat root treated with alachlor, while low molecular proteins(below 23 kd) were increased. Two-D gels showed that alachlor caused decrease(1-6 spots) or increase(7-10 spots) in number of polypeptides on silver staining. The intensity of some polypeptides of soluble proteins (molecular mass of 83 kd : 1, 2 spots, 70 kd : 3, 4 spots, and 47.5 kd : 5, 6 spots) decreased in alachlor treatment, whereas the intensity of other peptide bands (20 kd : 7 spot and 16 kd : 8, 9, 10 spots) increased. Oat root tip proteins present in the neutral zone are masked by diffusing of major proteins, but proteins in acid zone are resolved minor proteins.

• Publications of The Korean Astronomical Society
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• v.15 no.1
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• pp.21-29
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• 2000

We have analyzed 221 data of daily sunspot observations made during the period of January 1 to December 30 in 1999 and presented the daily relative sunspot numbers. During the year of 1999, our annual average of relative sunspot numbers is found to be 130.1. This number is obtained from the averaged daily number of 6.7 spot groups, in which there are about 45.9 distinct spots observed. According to the appearance of 384 spot groups, our analysis shows that the mean life time of spot group is about 5 day and 4.6 hours.

• Journal of Welding and Joining
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• v.5 no.1
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• pp.64-72
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• 1987

The Weldability of gavannealed steel using spot welder has been studied. The Results obtained are a follows; 1) Welds size and strength were increased depending on the welding time and welding current. But, the increasing rate has been decreased. 2) Deposited zinc has affected on the wear of welding tips and growth of welds but has not affected the weld's structures. 3) On shear testing of the specimen, button fracture has been observed and the value was approximately 540Kg (welds dia. approximately .phi.4mm)

• Publications of The Korean Astronomical Society
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• v.11 no.1
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• pp.251-261
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• 1996

We analyze 280 data of the daily sunspot observations during the period of January 1 to December 31 in 1995 and present the daily relative sunspot numbers. During the 1995, the preliminary annual average of the relative sunspot numbers is found to be 20.1 based on 7.9 distinct spots in a single group for 1.3 spot groups. According to the appearance of 366 spot groups, our analysis shows that the mean life time of spot group is about 5 day and 10.1 hours.

• Asian Journal of Turfgrass Science
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• v.14 no.1
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• pp.241-250
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• 2000

In 1997, a new disease on creeping bentgrass and Kentucky bluegrass occurred in the green and fairway of a few golf courses in Korea. The disease spread gradually throughout the country and became a threat to turfgrass management. Symptoms of the disease consisted of small, circular, and sunken patches sized 3~5cm in diameter. The disease named as a dollar spot following its characteristic symptoms of circular blight and bleach on the green. The disease peaked two times in a year from April to June and from late August to October and white cottony mycelia of the causal fungus developed on diseased turfs in the early morning when the conditions were favored. A causal fungus was consistently isolated from the infected tufgrass and seven isolates originated from seven golf courses located in six provinces were selected for further study. The fungus produced abundant white aerial mycelia on PDA and turned to dark gray or light brown as it aged. Width of the mycelium was ca. $5~8\mu\textrm{m}$. While sclerotia were not readily formed on the medium, scattered small and dark colored stromata were developed on the surface. The fungus grew well on PDA between 5 to $30^{\circ}C$ and maximally around $25^{\circ}C$. Based on investigated mycological and cultural characteristics, the causal agent of dollar spot was identified as Sclerotinia homoeocarpa. The fungus showed strong pathogenicity to several turfs as creeping bentgrass, Kentucky bluegrass, perennial ryegrass, tall fescues, and zoysiagrass.

• Journal of the Korean Society for Heat Treatment
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• v.24 no.5
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• pp.277-286
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• 2011

The spot weldability of metal joints between SD35 and SD30A steel was investigated. This study was aimed to determine the spot welding parameters (i.e. welding current and time) for reinforcement bar joint and to evaluate the weldability, mechanical strength, hardness and microstructure. The results indicated that shear strength and elongation of the welding joints at 12.5kA and 1000 ms were 26.7 $kgf/mm^2$ and 22%, respectively. And fracture distribution of them by using shear and tensile test showed 100% necking mode and 100% ductile mode, respectively.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.11-16
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• 2000

Purpose. Urinary calcium excretion using a 24-hr urine colledtion has been used for the diagnosis of hypercalciuria up to now. But It takes a lot of time and costs much. We have investigated on a more simple method for screening of hypercalciuria in children. Methods: We had retrospectively analyzed sodium, potassium, calcium and creatinine in spot urine of eighty-four patients with urinary symptoms from May 1998 to July 1998 in Korea university Guro hospital and compared the urinary Ca/Cr ratio with the Nin ratio. Using a urinary Nan ratio >2.68 as a cutoff value in predicting the occurrence of hypercalciuria, we measured its sensitivity, specificity, positive predictive value and the negative predictive value. Results: A direct relationship was found between urinary Na/K and Ca/Cr ratio (r=0.496, P<0.001, Ca/Cr : Na/K x 0.0167+0.061). Using a urinary Na/K ratio >2.68 as a cutoff value in predicting the occurrence of hypercalciuria, its sensitivity was found to be $100\%$ and its specificity $54.5\%$. The positive predictive value was $37.5\%$ and the negative predictive value $100\%$. Conclusions : Spot urine Na/K ratio is a valuable test for the screening of hypercalciuria in children.

• Journal of Welding and Joining
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• v.33 no.2
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• pp.56-61
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• 2015

IRW(Inverter Resistance Welding) process and DSW(Delta-spot welding) process for dissimilar materials of DP590 and Al5052 were performed to evaluate the welding quality and mechanical properties. IRW experiment was carried out with changing the welding current. The other welding parameters such as pressure force, weld time, squeezing time and holding time were fixed. On the anther hand, DSW experiment was performed using the process tape at welding current of 11.5kA. The other conditions were same as IRW conditions. The various testes such as shear tensile strength, nugget diameters, EDS, SEM and cross-sectional observation for weld zone was performed. As a result, IMC(Inter Metallic Compound) thickness at 11.5kA was thinner than those of 9.5kA and 10.5kA conditions. In addition, thined IMC layer was observed when high electric current apply to the materials(DP590 and Al5052) in a short time throught dissimilar resistance spot welding controling welding conditions. The relationship between the thickeness of IMC and current intensity was after discussed.