• The Plant Pathology Journal
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• v.20 no.4
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• pp.277-282
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• 2004

Amendments of a recirculating nutrient solution with potassium silicate were evaluated as a means to control Phytophthora capsici infections on pepper plant(Capsicum annuum L.). Supplying the solutions with 100 or 200 ppm of silicate significantly reduced motility, root decay, and yield losses attributed to infection of P. capsici. Treating inoculated plants with potassium silicate increased root dry weights and number of fruit, especially high-grade fruit. Results were slightly superior to non-inoculated controls. The two varieties, PBC 137 and PBC 602, responded similarly to the treatments. No significant differences were observed between the 100- and 200 ppm silicate treatments. Results were better when greenhouse conditions favored the spread of P. capsici. Silicon alone did not increase pepper yield, suggesting that it acts as a disease suppression agent rather than as a fertilizer, The phenomena by which silicon confers protection against P. capsici infection and disease development are not fully understood, but our results indicate that mechanisms other than a mechanical barrier to fungal penetration are involved.

• Journal of the Korean Institute of Navigation
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• v.21 no.3
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• pp.67-74
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• 1997

This paper described the method and the result of making a dynamic fiber optic gyrocompass measuring the heading angles of ships by processing the output signal from a constant rotating fiber optic sensor and also showed the measurement to test the performance of our system. Considerig an economical view we designed and ordered a cheap medium grade fiber densors increased not fiber length but the diameter of a fiber sensing loop. The scale factor and noise was 267mV/deg/s and 2 deg/hr/$\sqrt{Hz}(1{\sigma})$, respectively. We made the dynamic fiber optic gyrocompass by this sensor. We measured the heading angles in an arbitrary direction to evaluate the accuracy of our system and the root mean square error was $0.4^\circ$. Moreover, we measured the angles ineach direction of $45^\circ$. successive rotation to know whether this system has distoritions in a specific direction or not and the root mean square error in this case was $0.5^\circ$.

• Journal of Ginseng Research
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• v.36 no.4
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• pp.469-476
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• 2012

Raw ginseng root of Panax ginseng is graded according to its shape and the quality of its internal tissue. A variety of grades are sold with prices according to grade. If an inferior raw ginseng is purchased, the consumer experience an economic loss. This research was conducted in order to explore the possibility of developing a noninvasive method for investigating raw ginseng's internal tissue. It has been determined that computed tomography (CT) scanner images agreed with actual cross-sections of raw ginseng. CT images were obtained to assess the internal portions of raw ginseng, and CT scans of raw ginseng were thoroughly measured using the Hounsfield unit (HU) system, since it allows for a more detailed analysis compared to nuclear magnetic resonance imaging. HU is a measure of attenuation used for CT images, with each pixel being assigned a value using a scale on which air is defined as -1000, water as 0 and compact bone as +1000. It takes about one second to process are slice and produce an image of the raw ginseng by a one channel CT scanner. An image good enough to discriminate the internal tissues can be obtained in 1/24 seconds with a one-channel CT scanner. Using this method, images of raw ginseng can be obtained and the characteristics of the internal tissues can be observed in a short time.

• Journal of Periodontal and Implant Science
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• v.46 no.2
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• pp.107-115
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• 2016

Purpose: The aim of this study was to evaluate and compare tooth surface characteristics in extracted human molars after cervical enamel projections (CEPs) were removed with the use of three rotating instruments. Methods: We classified 60 extracted molars due to periodontal lesion with CEPs into grade I, II, or III, according to the Masters and Hoskins' criteria. Each group contained 20 specimens. Three rotating instruments were used to remove the CEPs: a piezoelectric ultrasonic scaler, a periodontal bur, and a diamond bur. Tooth surface characteristics before and after removal of the projections were then evaluated with scanning electron microscopy (SEM). We analyzed the characteristics of the tooth surfaces with respect to roughness and whether the enamel projections had been completely removed. Results: In SEM images, surfaces treated with the diamond bur were smoothest, but this instrument caused considerable harm to tooth structures near the CEPs. The piezoelectric ultrasonic scaler group produced the roughest surface but caused less harm to the tooth structure near the furcation. In general, the surfaces treated with the periodontal bur were smoother than those treated with the ultrasonic scaler, and the periodontal bur did not invade adjacent tooth structures. Conclusions: For removal of grade II CEPs, the most effective instrument was the diamond bur. However, in removing grade III projections, the diamond bur can destroy both adjacent tooth structures and the periodontal apparatus. In such cases, careful use of the periodontal bur may be an appropriate substitute.

• Journal of Korean Neurosurgical Society
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• v.40 no.3
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• pp.148-153
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• 2006

Objective : The authors conducted this study to present the long-term treatment outcomes [minimum 2 years] of Gamma knife radiosurgery[GKS] for trigeminal neuralgia[TN] and to demonstrate the correlation of treatment outcomes and the anatomical characteristics of TN. Methods : From 1997 to 2003, 44 consecutive patients suffering from medically intractable pain underwent GKS for TN. A single 4mm collimator was used with a median maximum dose of 80Gy [range $75{\sim}80Gy$] prescribed to the root entry zone of the trigeminal nerve. Median follow up duration was 30 months [range $24{\sim}78\;months$]. Anatomical measurements of trigeminal nerve in magnetic resonance images during GKS planning were correlated with clinical outcome. Results : Twenty-two patients [50%] achieved an excellent outcome [BNI grade I & II], 20 patients [45.5%] a good outcome [grade IIIa & IIIb], and only 2 patients [4.5%] a poor outcome [grade IV & V]. Eleven patients [25.0%] experienced pain recurrence after initial pain relief. Smaller volume of trigeminal nerve area irradiated more than 40Gy was significantly correlated with excellent outcome in both univariate and multivariate analyses respectively [P=0.033 and 0.040]. Conclusion : Anatomical considerations during the planning of GKS would be helpful for predicting clinical outcome in TN.

• Journal of Periodontal and Implant Science
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• v.51 no.3
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• pp.163-178
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• 2021

Purpose: The aim of this study was to evaluate clinical factors affecting the longevity of fixed retainers and the influence of fixed retainers on periodontal health in periodontitis patients. Methods: In total, 52 patients with at least 2 years of follow-up after periodontal and orthodontic treatment were included in this study. After scaling and root planing, orthodontic treatment with fixed appliances or clear aligners was performed. Fixed retainers with twist-flex stainless steel wires were bonded to the palatal or lingual sides of anterior teeth. Changes in clinical parameters, including the plaque index, gingival index, calculus index (CI), probing pocket depth, and radiographic bone levels, were evaluated before bonding of fixed retainers and at a 12-month follow-up. Cumulative survival rates (CSRs) for retainer failure were evaluated according to sex, site, CI, stage of periodontitis, and the severity of the irregularity with the log-rank test and hazard ratios (HRs). Results: Twelve months after bonding of fixed retainers, improvements were observed in all clinical parameters except CI and radiographic bone gain. The overall CSR of the retainers with a CI <1 at the 12-month follow-up after bonding of fixed retainers was significantly higher than that of the retainers with a CI ≥1 at the 12-month follow-up (log-rank test; P<0.001). Patients with stage III (grade B or C) periodontitis had a higher multivariate HR for retainer failure (5.4; 95% confidence interval, 1.22-23.91; P=0.026) than patients with stage I (grade A or B) periodontitis. Conclusions: Although fixed retainers were bonded in periodontitis patients, periodontal health was well maintained if supportive periodontal treatment with repeated oral hygiene education was provided. Nonetheless, fixed retainer failure occurred more frequently in patients who had stage III (grade B or C) periodontitis or a CI ≥1 at 12-month follow-up after bonding of fixed retainers.

• Journal of Practical Agriculture & Fisheries Research
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• v.17 no.1
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• pp.73-84
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• 2015

Comparison of the standard and instruction for grade and quality of landscape plants between Korea and foreign countries indicates that the individual country characteristically develops and uses their own standards for landscape plants. Ultimate aim of these regulations is to develop the standard of landscape plants classified by kinds, types and purposes to improve the quality of landscape plants. This study analyzed the differences of standards and instructions for landscape plants between Korea and other countries such as Germany, Switzerland, America, Canada and Japan. Our results indicated that Korea and Japan used the diameter at 1.2m above from ground surface for the diameter at breast height(DBH) whereas Germany and Switzerland at 1.0m above from ground surface. In case of America and Canada, the standard of landscape plants included crown width, height and DBH of plants. In Germany, the standard for creeping plants and herbaceous flowers was determined by the type and the root size of plants with the standard of containers(seven to eleven types). This research would be helpful for developing the practical and environmentally suitable guideline for the grade and quality of landscape plants and also for developing the standardized distribution structures and cultivation techniques for landscape plants in Korea.

• Journal of Ginseng Research
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• v.39 no.2
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• pp.94-104
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• 2015

Background: Ginseng (Panax ginseng Meyer) is an important medicinal herbs in Asia. However, ginseng varieties are less developed. Method: To developed ginseng varieties, a pure line selection method was applied in this study. Results: Gumpoong was testing of 4-yr-old specimens in 2002, the proportions of the below-ground roots that were rusty colored for Gumpoong was 1.29 in Daejeon and 1.45 in Eumseong, whereas the proportions for its yellow berry variant were 2.60 and 2.45 in the two regions, respectively. Thus the Gumpoong was resistant to root rust. Sunpoong has a high yielding property. Its average root weight is 70.6 g for 6-yr-old roots. Its yield is 2.9 kg/$1.62m^2$ and the rate of heaven- and earth-grade product is 20.9%, which is very high compared to 9.4% for Yunpoong. Sunone is resistance to root rot and the survival rate of 4-yr-old roots was 44.4% in 1997, whereas that of the violet-stem variant landrace was 21.7%. Sunhyang has content of arginyl-fructosyl-glucose (AFG), which produces the unique scent of red ginseng, is $95.1{\mu}mol/g$ and greater than the $30.8{\mu}mol/g$ of Chunpoong in 6-yr-old plants. Sunun and Cheongsun are being nurtured to protect genetic resources. Conclusion: Developed ginsneg varieties will be used as the basis for the protection of genetic resources and breeding.

• Research in Plant Disease
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• v.13 no.2
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• pp.104-109
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• 2007

Pink root disease of onion, a known worldwide constraint upon onion production, significantly reduces crop levels in the main Korea cultivation area. In order to examine the effect of flooding on incidence of pink root disease caused by Pyrenochaeta terrestris and on onion growth and on populations of soil fungi, field experiments were conducted during two seasons, 2003/04 and 2004/05 at Onion Research Institute. Populations of soil fungi from fields were assayed on selective media. Flooding treatment was effective in reducing populations of P. terrestris, Pythium spp., and Rhizoctonia sp. in soil; fungal populations in soils flooded for 90 days were reduced to 1/2 to 1/3 of those in non-flooded soils. In nursery bed, protective activities of soils flooded for over 60 days were 93.5 to 99.2% and their pink root incidences were less than 5%, which were 1/11 to 1/18 of that in control. Increased yield of onion bulbs was associated with control of soil borne pathogenic fungi by flooding treatments. As flooding period was prolonged, bulb grade showed the tendency to increase. Soil flooding for over 60 days resulted in effective disease control, facilitated accurate planning of plant population in the field, extension of the growing-season and consequently higher yields of better quality.

• East Asian mathematical journal
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• v.32 no.4
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• pp.545-563
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• 2016

The aim of this study was to observe processes and implication to a given program for the 20 gifted children grade 5 by making the number from 1 to 100 with natural numbers 4,4,9 and 9. Revelation of creativity, mathematical tendency of students and meaningful responses were observed by the qualitative records of this game activity and the analysis of result. The major result of a study is as follows: The mathematical creativities of students were revealed and developed by this activity. And the mathematical attitude were changed and developed, so student could actively participate. And students could experience collaborative and social composition learning by presentations and discussion, competition with a permissive atmosphere and open-game rule. It was meaningful that mathematical ideas (negative number, square root, factorial, [x]: the largest integer not greater than x, absolute value, percent, exponent, logarithm etc.) were suggested and motivated by students themselves.