• Journal of Sericultural and Entomological Science
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• v.20 no.1
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• pp.15-23
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• 1978

This studies have been carried out for several years to develop more better urea resin treating process on silk textiles which may be better crease resist without harming on the textile touch feeling. Specially, this paper payed attention to minimize the necessary formaldehyde content to be condensed with urea and created a new processing method which is named as Homo Metalic Urea Resin found to be better than urea resin process. The obtained results are as followings. 1. The prepared urea resin was found to be smell-less because of minimized formaldehyde content is the least than any other reports carried out before than this. 2. A new type of urea resin has been created by using uric 2incchloride and formaldehyde which is named as Homo Metalic Urea Resin. This processing method may carry both weighing process and urea resin process. 3. Crease resistance, stiffness and bulkiness were increased through such resin treats. Homo metalic urea resin process showed better results than the urea resin process. 4. Spun silk or low twisted silk have shown better crease resistance than raw silk or high twisted silk upon the both resin treats. 5. Both treat methods were found to be good economical feasibility upon the silk finishing process. 6. Tenacity and elongation of silk fibers were found to decrease some what because of grafting or weighing results. 7. Wooly silk has been also created with specific urea resin process. Such silk could be obtained by formaldehyde gas treat with urea soaken silk in a chamber, which induced to form scale on the surface of silk fibers.

• The Journal of the Acoustical Society of Korea
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• v.24 no.1
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• pp.29-37
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• 2005

This paper proposes an automatic genre classification system for Korean traditional music. The Proposed system accepts and classifies queried input music as one of the six musical genres such as Royal Shrine Music, Classcal Chamber Music, Folk Song, Folk Music, Buddhist Music, Shamanist Music based on music contents. In general, content-based music genre classification consists of two stages - music feature vector extraction and Pattern classification. For feature extraction. the system extracts 58 dimensional feature vectors including spectral centroid, spectral rolloff and spectral flux based on STFT and also the coefficient domain features such as LPC, MFCC, and then these features are further optimized using SFS method. For Pattern or genre classification, k-NN, Gaussian, GMM and SVM algorithms are considered. In addition, the proposed system adopts MFC method to settle down the uncertainty problem of the system performance due to the different query Patterns (or portions). From the experimental results. we verify the successful genre classification performance over $97{\%}$ for both the k-NN and SVM classifier, however SVM classifier provides almost three times faster classification performance than the k-NN.

• Restorative Dentistry and Endodontics
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• v.19 no.2
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• pp.549-567
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• 1994

Restoration of severly damaged teeth after endodontic treatment had been an interest to many dentists, and it is a fact that there have been lots of studies about it. In these days, although we have used Para-Post, pins, threaded steel post, cast gold post and core, and so on, as a method of restoration frequently, it has been in controversy with the influence of them on the teeth and surrounding periodontal tissue. In this study, we assume that the crown of the upper incisor have severly damaged, so, after the root canal therapy, 4 types of restoration had been carried out; 1) coronal-radicular amalgam restoration, 2) after setting up the Para-Post, restore with composite resin core only, 3) after setting up the Para-Post; restore with amalgam core, then cover with the PPM crown 4) after setting up the Para-Post, restore with composite core, then cover with the PPM crown. After restoration, in order to observe the concentration of stress at internal portion of the teeth and the sourrounding periodontal tissue, developing a 2-dimensional finite element model of labiopalatal section, then loading forces from 3 direction - direction of 45 degrees from lingual side near the incisal edge, horizontal direction from labial height of contour, vertical direction at the incisal edge-were applied. The analyzed results were as follows: 1. Stress of the normal central incisor was concentrated on the dentin aroundpulp chamber, labiocervical portion of a tooth and root apex, but with the alveolar bone, in the case of load from the direction of 45 degrees from lingual side near the incisal edge showed remarkable concentration of stress: 2. Coronal-radicular amalgam technique -showed less concentration of stress on the root and surrounding periodontal tissue than the restoration with the Para-Post. 3. The von Mises equivalent stress on the Para-Post showed maximum value at root-core junction rather than both ends and model with PPM restoration with amalgam core showed the least concentration of stress. Only the force from horizontal direction showed large shear stress on internal portion of the root, root apex and alveolar bone. 4. PPM crown with composite core rarely showed the concentration of stress on root and periodontal tissue. 5. As for alveolar bone, remarkable shear stress was concentrated on labial and palatal side by horizontal load.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.229-239
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• 2011

This study was carried out to establish an improved bioassay system on the side of practicality, pre-emergence bioassay which is more effective in developing soil application natural herbicides. A miniaturized method which have a 50 cm2 of soil surface area and was efficient by 7 times compared to the existing soil application assay ($350cm^2$ of soil surface area) was established, in which four weed species (Echinochloa crus-galli, Digitaria sanguinalis, Aeschynomene indica, and Abutilon theophrasti) were planted and grown in greenhouse. This would be applicable when the amount of screening compound is much more than 50 mg. The initial application rate was desirable at $10,000{\mu}g\;mL^{-1}$. On the other hand, the 6 well plate assay which has 4 weed species in each well containing upland soil and could be conducted in growth chamber, was established. This assay was resulted in minimizing in level of 1/14 test volume and 1/14 amounts of test compound to the conventional method that has been used for screening of synthetic compounds in KRICT, and applicable for the small amount of test compound (less than 10 mg). Therefore, the improved bioassays established in this study would be helpful for a rapid and efficient development of soil application natural herbicides.

• Journal of the Korean Vacuum Society
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• v.19 no.5
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• pp.371-376
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• 2010

The GaAs epitaxial layers were grown on Si(100) substrates by molecular beam epitaxy (MBE) using the two-step method. The Si(100) substrates were cleaned with three different surface cleaning methods of vacuum heating, As-beam exposure, and Ga-beam deposition at the substrate temperature of $800^{\circ}C$ in the MBE growth chamber. Growth temperature and thickness of the GaAs epitaxial layer were $800^{\circ}C$ and $1{\mu}m$, respectively. The surface structure and properties were investigated by reflection high-energy electron diffraction (RHEED), AFM (Atomic force microscope), DXRD (Double crystal x-ray diffraction), PL (Photoluminescence), and PR (Photoreflectance). From RHEED, the surface structure of GaAs epitaxial layer grown on Si(100) substrate with Ga-beam deposition is ($2{\times}4$). The GaAs epitaxial layer grown on Si(100) substrate with Ga-beam deposition has a high quality.

• Journal of the Korean Vacuum Society
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• v.11 no.2
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• pp.113-118
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• 2002

We developed engineering methods to control gas flow in a plasma reactor in order to achieve good etch depth uniformity for large area GaAs etching. Finite difference numerical method was found quite useful for simulation of gas flow distribution in the reactor for dry etching of GaAs. The experimental results in $BCl_3/N_2/SF_6/He$ ICP plasmas confirmed that the simulated data fitted very well with real data. It is noticed that a focus ring could help improve both gas flow and etch uniformity for 150 mm diameter GaAs plasma etch processing. The simulation results showed that optimization of clamp configuration could decrease gas flow uniformity as low as $\pm$ 1.5% on an 100 mm(4 inch) GaAs wafer and $\pm$ 3% for a 150 m(6 inch) wafer with the fixed reactor and electrode, respectively. Comparison between simulated gas flow uniformity and real etch depth distribution data concluded that control of gas flow distribution in the chamber would be significantly important in order or achieve excellent dry etch uniformity of large area GaAs wafers.

• Progress in Medical Physics
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• v.12 no.2
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• pp.147-153
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• 2001

We have discussed that the total body irradiation(TBI) dose distribution of 6 and 10 MV photon beams, also differences between calculation dose use of compensator sheet and measurements in humanoid phantom. Total body irradiation and hemi-body irradiation(HBI) can be effectively performed when uniformity of dose distribution is estabilished. The method of TBI and HBI dosimatry requires special considerations related to technique, long distance and very large field, machine parameter, patient positioning. TBI and HBI with megavoltage photon beams requires basic dosimatric data which have to be measured directly or derived from the standard beam data. The semiconductor detector and ion chamber were positioned at a dmax depth, mid depth, and its specific ratio was determined using a scanning data by RFA-7 3-dimensional water phantom and solid phantom. The effective source axis distance 380 cm, the field size from 120 cm to 152 cm, isodose distributions were analyzed as a function of the thickness in phantom. Also, have discussed that the measurement of basic data for clinical photon beams for dosage calculations, data calculation sheet and the use of tissue compensation to improve dose uniformity. We have improved a dose uniformity in the TBI and HBI method.

• Journal of the Korean GEO-environmental Society
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• v.17 no.6
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• pp.23-31
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• 2016

Nowadays abnormal coldness happens frequently in Korea and frost heaving causes unexpected ground deformation which results in severe problems for structures such as roadway, railroad and cutoff slope. 'Frost heave' as one of the primary phenomenon is considered to be an important factor together with 'adfreeze bond-strength' and 'creep deformation' for structural design process in permafrost area. Therefore, the fundamental study for frost heave has to be preceded for design of geo-structures in cold region. While various experimental apparatuses have been developed, there still exist a certain level of limitation to evaluate the frost-heave characteristics as design parameters. There are no standard testing method and criteria for analyzing frost heaving in Korea because temperature controlled testing apparatuses including a freezing chamber are expensive. In this paper, a new standard freezing and thawing testing apparatus is introduced, which simulates various freezing and thawing conditions in a soil specimen by using a temperature controlled triaxial cell. Frost heaving tests were performed to assess the new testing apparatus and experimental procedure to evaluate frost heaving for soils is proposed.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.359-366
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• 1996

Background : Eosinophilic leukocytes are prominent cellular participants in the pathogenesis of allergic disease and asthma. Chemotaxis is still a very useful method in evaluating the response of human eosinophil to novel modulators. Degranulated mast cells and activated T lymphocytes are responsible for the pathophysiology of asthma and tryptase is one of most important proteases released after activation of mast cells. The purpose of this study was to investigate the actions of trypsin and chymotrypsin on eosinophils in terms of chemotaxis and activation. Method : Eosinophils were isolated by negative immunoselection from the peripheral blood of atopic donors. Chemotaxis was studied by using micro-Boyden chambers and ECP release was assayed by fluoroimmunoassay. Results : Eosinophil showed a chemotactic response to trypsin. Maximal chemotactic response was with $1000{\mu}g/ml$ trypsin ($56.52{\pm}14.50$/HPF) which was comparable to PAP. But chymotrypsin showed no significant chemotactic response to eosinophils. Trypsin at the concentration of 10, 100, $1000{\mu}g/ml$ induced secretion of ECP, which at the concentration of $10{\mu}g/ml$ represented about 2.7 times of the spontaneous rate of release. Soybean protease inhibitor reduced trypsin induced ECP release. Conclusion : Trypsin can induce chemotactic response to eosinophils and activation of eosinophils that can induce secretion of ECP. On the contrary, chymotrypsin showed no direct effect on eosinophils. We propose a role of trypsin on the chemotaxis and activation of eosinophils.

• Journal of IKEEE
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• v.24 no.1
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• pp.347-353
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• 2020

In this paper, the durability of an electromagnetic metamaterial absorber is verified in a temperature varying condition mimicking a maritime environment for the purpose of applying it to reduce the radar cross section of an integrated mast of the next-generation destroyer. To validate the durability, the reflectance of the electromagnetic metamaterial absorber was measured after storing it in a chamber that can control the temperature according to Procedure I of Method 501.7 included in MIL-STD-810H. Before and after the environmental test, both of the measured reflectances were retained less than -10 dB over the X band, that can guarantee the stealth functionality.