• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.421-432
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• 1994

The local route of antibiotic administration can accomplish higher therapeutic doses in subgingival sites than those possible by systemic therapy. This investigation assessed on the clinical and microbiological effect of 30% Minocycline loaded polycaprolactone film (Mino-strip) on rapidly progressive periodontitis. Mino-strip was applied in the periodontal pockets of 15 patients with clinically diagnosed as a rapidly progressive periodontitis. 8sites for each patient with a 5mm probing pocket depth were selected in split mouth design and were assigned into group. i.e., placebo(group 1), supragingival scaling and R/P(group 2), Mino-strip applied only(group 3), R/P and Mino-strip applied(group 4). Supragingival scaling and oral hygiene instruction were performed 1 wk before experiment. Mino-strip was applied weekly on day 0 and 7. Clinical and microbiological test were performed on day 0, 7, 14, 28, 56. In R/P and Mino-strip applied group, Gingival index, GCF volume, probing depth and loss of attachment level were significantly reduced after the first weeks following treatment. In R/P and Mino-strip applied group, the relative proportions of spirochetes and motile rods were significantly reduced and the proportions of cocci and non motile rod were correspondingly increased for eight weeks following treatment. In R/P and Mino-strip treated group, total anaerobic and aerobic bacterial count were significantly decreased for the first two weeks following treatment and streptococcus count was decreased for eight weeks following treatment. In R/P and Mino-strip applied group, P. gingivalis, P. intermedius, B. forsythus, A. actinomycetemcomitans, F. nucleatum, E. corrodens, C. rectus counts were significantly reduced after the first week following treatment. According to this study, it is appeared that 30% Minocycline-loaded polycaprolacton film was effective in the treatment on rapidly progressive periodontitis.

• Journal of Biomedical Engineering Research
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• v.32 no.1
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• pp.37-44
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• 2011

This paper describes the development and assessment of conductive fabric sensor for evaluating knee movement using bio-impedance measurement method. The proposed strip-typed conductive fabric sensor is compared with a dot-typed Ag/AgCl electrode for evaluating validity under knee movement condition. Subjects are composed of ten males($26.6{\pm}2.591$) who have not had problems on their knee. The strip-typed conductive fabric sensor is analyzed by correlation and reliability between a dot-typed Ag/AgCl electrode and the strip-typed conductive fabric sensor. The difference of bio-impedance between a dot-typed Ag/AgCl electrode and the strip-typed conductive fabric sensor averages $7.067{\pm}13.987\;{\Omega}$ As the p-value is under 0.0001 in 99% of t-distribution, the strip-typed conductive fabric sensor is correlated with a dot-typed Ag/AgCl electrode by SPSS software. The strip-typed conductive fabric sensor has reliability when it is compared with a dot-typed Ag/AgCl electrode because most of bio-impedance values are in ${\pm}1.96$ standard deviation by Bland-Altman Analysis. As a result, the strip-typed conductive fabric sensor can be used for assessing knee movement through bio-impedance measurement method as a dot-typed Ag/AgCl electrode. Futhermore, the strip-typed conductive fabric sensor is available for wearable circumstances, applications and industries in the near future.

• Journal of Korean Society of Transportation
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• v.24 no.7 s.93
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• pp.7-14
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• 2006

Most researches about rumble strips have Presented only the before-and-after analysis of the accidents. So, Researchers have not dealt with the estimation of rumble strip's effectiveness on the driver's alertness. In this study. the effectiveness of the rumble strips on the driver's alertness was estimated by measuring the bio-signal transmitted from the driver. The bio-signal acquired for this experiments were theta wave in central lobe. The experimental results revealed that the theta waves as measured form the drivers's head while in the rumble strip section differed from those while in non-rumbled section; 74 percent decrease in theta wave value, respectively. This fact finding could mean that the driver's alertness increased from 74 percent while in the rumble strip section of the road. In all five trials of driving experiments on the rumble strip section, all the drivers showed the best alertness as measured by the theta waves in the first driving trial.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.132-135
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• 2005

The purpose of this study was to propose the modified strip crown technique for esthetic restoration of primary anterior teeth using glass fibers. Celluloid crown form(3M, USA), Z100(P shade, 3M, USA). Aeliteflo(Bisco Inc., USA), and Clearfil SE Bond(Kuraray Medical Inc., Japan) were used for this technique. Mesh type of glass fiber(TESCERA Fiber Mesh, Bisco Inc, USA) was used for reinforcing material. After trimming the celluloid crown form, resin adhesive and flowable resin were applied on the pre-shaped glass fiber mesh. That mesh was placed on the lingual surface of inside of celluloid crown form and followed by light activation. Composite resin was filled into the celluloid crown form and put it on a prepared tooth and then light activated and finished the margin. The new modified strip crown technique can provide esthetics and increased durability for restoration of primary anterior teeth.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.5
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• pp.409-414
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• 2017

In the thin strip coiling process, it is necessary to use a sleeve with a mandrel to prevent excessive deformation of the strip. The stress distribution in the sleeve and strip is an important factor to determine the size of the sleeve. However, an experimental approach is almost impossible because of the accumulation of high pressure. A finite element (FE) model of the strip coiling process was developed in this study. Then, the radial and hoop stresses on the sleeve and strip were investigated using FE analyses. The theoretical values and analysis results under idealized conditions were compared to verify the FE model. The effect of the strip thickness on the stress distribution was also investigated. The radial stress increased by 6.3 times for a 1-mm-thick strip at the coil starting point. The radial stress at the sleeve increased by 14.8 % with a stacked thickness of 90 mm because of the reaction force applied by the mandrel.

• Journal of Korean society of Dental Hygiene
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• v.3 no.2
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• pp.197-208
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• 2003

This study was implemented for 84 students of dental hygiene to show the correlation between dental caries experience and improved caries activity test. Dental caries experience for the sample groups was examined and stimulative saliva secreted for 5 minutes was collected into the tube to check saliva secretion rate. Dentocult LB test was executed to observe Lactobacilli colonies after 96 hour cultivation of culture slides moistened with stimulative saliva. Dentocult SM test(screening strip, site strip) was done to measure SM colonies distribution after 48 hour cultivation of culture strips applied with collected saliva and dental plaque respectively, and salivary buffering capacity was checked by means of Dentobuff strip kit. Following conclusions are obtained after examining the relation between Dentocult LB, Dentocult SM, Dentobuff strip test results and DMFT index, salivary secretion rate. 1. Showed no significant difference between Dentocult LB test results and DMFT index, salivary secretion rate. 2. Showed no significant difference between Dentocult SM(screening strip) test results and DMFT index, salivary secretion rate. 3. Showed significant difference between Dentocult SM(site strip) test results and DMFT index(pE0.05), but showed no significant difference between Dentocult SM(site strip) test results and salivary secretion rate. 4. Showed no significant difference between Dentobuff strip test results and DMFT index, but showed a very wide difference between Dentobuff strip test results and salivary secretion rate(pE0.01).

• Journal of Korea Foundry Society
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• v.20 no.2
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• pp.122-128
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• 2000

Strip casting process is a new technology that makes a near net shape thin strip directly from molten metal. With this process, a large amount of energy and casting cost could be decreased from the abbreviation of reheating and/or hot rolling process. Ductile cast iron which has spheroidal graphite in the matrix is the most commercial and industrial material, because of its supreme strength, toughness, and wear resistance etc. But it cannot be produced to the thin strip owing to difficulty in rolling of ductile cast iron. In this study, ductile cast iron strips are produced by the twin roll strip caster, with different chemical compositions of C, Si, and Mn contents. And then heat-treated, microstructures and mechanical properties are examined. The microstructures of as-cast strip are that of white cast iron which consists of the mixture of cementite and pearlite, but the equiaxed crystal zone of the pearlite or segregation zone of cementite exists in the center region of the strip thickness, which cannot be observed in the rapidly solidified metallic mold cast specimens. This structure is supposed to be formed from the thermal distribution of strip and the rolling force. Comparing with the structures of each strips after heat treatment, increasing Si content makes smaller spheroidal graphite and more compact in the matrix, furthermore the less of Mn content makes the ferrite matrix be obtained clearer and easier. As a result of the tensile test of graphitization heat-treated strips, the yield strengths are about 250 MPa, the tensile strengths are about $430{\sim}500$ MPa, and the elongations are about $10{\sim}13%$. In the case of the strip which has the smaller and more compact spheroidal graphite in the ferrite matrix, the higher tensile strength and better drawability could be obtained.

• International Journal of Highway Engineering
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• v.15 no.6
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• pp.93-101
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• 2013

PURPOSES : The rumble strip installed at the highway near the tollgate has the purpose to reduce the vehicle velocity or prevent sleepiness by awakening people to the danger. These rumble strip has different vibration decibel from the rumble strip shapes, resulting in some fatigue damage to human because a driver suffers from a lot of stress and displeasure. In this connection, the objective of this paper is to analyze the vibration decibel perceived by a driver in the vehicle under some conditions. METHODS : The vibration decibel conveyed from the tire can be analyzed. The frequency analysis methods were used according to DFT (Discrete Fourier Transform) analysis, FFT (Fast Fourier Transform) analysis, CPB (Constant Percentage Bandwidth) analysis. But the frequency analysis method in this paper is the 1/24 OCT(Octave) band analysis because of the convenience of the analysis and the overall vibration amplitude along the frequency. RESULTS : By using the results of the vibration decibel after analyzing the 1/24 OCT band analysis, these results can be compared from some conditions (e.g., rumble strip shape, uniform velocity of a vehicle, road condition, mass of a vehicle). As a result, the numerical values of decibel are not directly proportional to the vehicle velocity. CONCLUSIONS : At the condition that a vehicle is passing by the rumble strip, the value of a vibration decibel at the rumble strip of the cylinder shape is smaller than the rumble strip of rectangular shape regardless of the rumble strip depth and width. At the mass condition, the more a vehicle is massive, the more the vibration decibel increases. At the road condition, the vibration decibel at the wet road is smaller than the value at dry road condition.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.313-316
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• 2008

This work sought to examine the suitability of twin roll strip casting for Ag-27%Cu-25%Zn-3%Sn brazing alloy (BAg-7A) and to investigate the mechanical properties and microstructure of the strip. The effect of aging heat treatment on the properties was also studied,. This new manufacturing process has applications in the production of the brazing alloy. XRD and microstructural analysis of the Ag-27%Cu-25%Zn-3%Sn strip represented eutectic microstructure of a Cu-rich phase and a Ag-rich matrix regardless of heat treatment. The results of mechanical tests showed tensile strength of 470MPa, a significant enhancement, and an 18% elongation of the twin roll casted strip, due mainly to the solid solution strengthening of Zn atoms (${\sim}20%$) in the Cu-rich phases. Tensile results showed gradually decreasing strengths and increasing elongation with aging heat treatment. Microstructural evolution and fractography were also investigated and related to the mechanical properties.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.3
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• pp.861-871
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• 1996

In this study, a fuzzy control algorithm was developed for the randomly irregular shape of cold-rolled strip. Currently developed fuzzy control algorithm consists of two parts: the first part calculates the changes of work and intermediate roll bender forces based on the symmetric part of the irregular strip shape, and the second part calculates the weighting factors based on the asymmetric part and modifies the pre-determined roll bender forces according to the weighting factors. As a result of this, bender froces applied at the both sides of the cold-rolled strip were different. In order to simulate the continuous shape control. fuzzy controller developed was linked with emulator which was developed based on neural network. The fuzzy controller and emulator developed simulated the cold rolling process until irregular shape converged to a tolerable range in producing uniform cross-sectional strip shape. The results obtained from the simulation were reasonable for various irregular strip shapes.