• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.12
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• pp.1984-1994
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• 1989

Techniques for approximating digitalcurves by polygonal lines are a valuable tool for image analysis and data compression. S. Shilien proposed a method for segmenting a digital curve into digital straight line segments digital straight line segments which are not satisfied with the structural properties, and have more than one break point by Shilien's method. Here, the structural representation of digital straight lines and digital staight line segments is described. And a method for segmenting a digital curve into digital straight line segments which are not satisfied with the structural properties, and have more than one break point by Shilien's method. Here, the structural representation of digital straight lines and digital staight line segments is described. And a method for segmenting a digital curve into digital straight line segments which may be not satisfied with the structural properties is proposed. The number of break points extracted by this method is less than that by S. Shilien's method from the digital curve which includes the digital straight line segments not satisfied with the structural properties.

• Geomechanics and Engineering
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• v.24 no.2
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• pp.129-141
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• 2021

The vacuum preloading method has been used in many countries for soil improvement and land reclamation. However, the treatment time is long and the improvement effect is poor for the straight-line vacuum preloading method. To alleviate such problems, a novel combined air booster and straight-line vacuum preloading method for shallow ground treatment is proposed in this study. Two types of traditional vacuum preloading and combined air booster and straight-line vacuum preloading tests were conducted and monitored in the field. In both tests, the depth of prefabricated vertical drains (PVDs) is 4.5m, the distance between PVDs is 0.8m, and the vacuum preloading time is 60 days. The prominent difference between the two methods is when the preloading time is 45 days, the injection pressure of 250 kPa is adopted for combined air booster and straight-line vacuum preloading test to inject air into the ground. Based on the monitoring data, this paper systematically studied the mechanical parameters, hydraulic conductivity, pore water pressure, settlement and subsoil bearing capacity, as determined by the vane shear strength, to demonstrate that the air-pressurizing system can improve the consolidation. The consolidation time decreased by 15 days, the pore water pressure decreased to 60.49%, and the settlement and vane shear strengths increased by 45.31% and 6.29%, respectively, at the surface. These results demonstrate the validity of the combined air booster and straight-line vacuum preloading method. Compared with the traditional vacuum preloading, the combined air booster and straight-line vacuum preloading method has better reinforcement effect. In addition, an estimation method for evaluating the average degree of consolidation and an empirical formula for evaluating the subsoil bearing capacity are proposed to assist in engineering decision making.

• Korean Journal of Cleft Lip And Palate
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• v.11 no.2
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• pp.77-82
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• 2008

The harmonious lip length, residual scar and Cupid's bow width and peak with a normal side are the aims of a unilateral cleft lip repair. Also, long term amelioration without necessary of revisional surgeries may be the ideal conditions. No one method can satisfy the wide varieties of cleft lip deformities. Recently with rearrangement of paraoral muscle and some modifications, a straight line repair technique has been concerned again. Straight scar line, simplicity, and short learning curve are the advantages of the straight line technique. Here two cases of the simple straight line technique were presented and discussed for its usefulness and reliability with short reviews of previous reports.

• The Journal of the Acoustical Society of Korea
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• v.27 no.4
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• pp.200-206
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• 2008

This paper presents a method of quantization to extract quantization parameters using the straight-line and DCT (Discrete Cosine Transform) for two splited frequency bands. As the number of harmonic is variable frame to frame, harmonics in low frequency band is oversampled to fix the dimension and straight-lines present a spectral envelope, then the discontinuous points of straight-lines in low frequency is sent to quantizer. Thus, extraction of quantization parameters using the straight-line provides a fixed dimension. Harmonics in high frequency use variable DCT to obtain quantization parameters and this paper proposes a method of quantization combining the straight-line with DCT. The measurement (If proposed method of quantization uses spectral distortion (SD) for spectral magnitudes. As a result, The proposed method of quantization improved 0.3dB in term of SD better than HVXC.

• Journal of Power System Engineering
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• v.3 no.1
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• pp.74-79
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• 1999

This paper describes formulation for algorithm of time historical response analysis of vibration for straight-line structure. This method is derived from a combination of the transfer stiffness coefficient method and the Newmark method. And this present method improves the computational accuracy of the transient vibration response analysis remarkably owing to several advantages of the transfer stiffness coefficient method. We regarded the structure as a lumped mass system here. The analysis algorithm for the time historical response was formulated for the straight-line structure containing crooked, tree type system. The validity of the present method compared with the transfer matrix method and the Finite Element Method for transient vibration analysis is demonstrated through the numerical computations.

• Applied Microscopy
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• v.42 no.3
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• pp.129-135
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• 2012

In this study, the changes in hair quality before and after Magic straight perm have been evaluated through a hair damage measurement method. For this, a healthy high school student's (age18 years) wavy hair was selected and permed on the left and right sides. Then, the changes caused by physical methods which were applied during the fl at iron-based Magic straight perm were evaluated based on the hair damage measurement method before and after the Magic straight perm. According to the protein release test after the Magic straight perm, 1.26% in average and 0.14% was observed in Cool Magic straight perm sample. In a field emission scanning electron microscopy (FE-SEM) test, saw teeth-shaped partial desquamation of cuticle cells and impurities were observed in the warm-treated hair sample. In atomic force microscope (AFM), line-profile is a method to represent roughness data on hair. According to analysis on 3-dimensional (3D) images, the hair with Cool Magic straight perm was lower than the hair with Warm Magic perm in terms of the color change of 3D images. In addition, vertical changes were observed in the hair with Cool Magic perm. As a result, irregular surface roughness was observed. This study proposed a method to minimize hair damage by cooling down the heat with the cool hair straightener as soon as the Warm Magic was finished.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.2
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• pp.146-156
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• 2002

In this paper, a new virtual-straight line parameter determination methodology and fast time domain simulation technique for non-uniform interconnects are presented and verified. Time domain signal response of interconnects circuit considering the characteristic of non-linear transistor is performed by using model order reduction method. Since model order reduction method is peformed by using per unit length parameters, virtual- straight line parameters for non-uniform interconnects are determined. Its method is integrated into Berkeley SPICE and shown that time domain signal responses using proposed method have a good agreement with the results of conventional circuit simulator HSPICE. The proposed method can be efficiently employed in the high-performance VLSI circuit design since it can provide a fast and accurate time domain signal response of complicated multi - layer interconnects.

• Restorative Dentistry and Endodontics
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• v.27 no.4
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• pp.432-440
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• 2002

The purpose of this study is to identificate root canal system including ideal access placement, root curvature, canal configuration, incidence of isthmus in mandibular incisors for success of endodontic treatment. 200 mandibular incisors were selected. The ideal access placement was determimed as follows. The teeth there radiographed from mesiodistal and buccolingual views using intraoral dental film. The image was divided into coronal, middle and apical third using the proximal film. Straight line access was determined by measuring the faciolingual canal width and placing points at midway point between the buccal and lingual wall at the junction of the middle and apical third and at the juntion of coronal and middle third of the root canal. A line was drawn connecting these two points extending through the crown of the tooth. The point at which the line crossed the external crown surface was recorded as facial, incisal, lingual. Degree of root curvature was determined by Schneider Protractor Method. Both section method and clearing method were used in this study. By section method, 100 mandibular incisors were embedded in clear resin and transeverse serial sectioned at 0.5, 1.0, 2.0, 3.0, 4.0, 5.0mm level from root apex. The resected surfaces were stained by methylene blue and examined under $\times$40 magnification with a stereomicroscope. By clearing method, 100 mandibular incisors were cleared in methysalicylate after decalcification with 10% nitric acid and evaluated under $\times$18 magnification with a stereomicroscope. The results were as follows ; 1. 29% had the center of the plotted straight-line access facial to incisal edge, whereas 71% had straight-line access at the incisal edge. When incisal wear classified as extensive, the straight-line access was plotted on the incisal edge 95.5%. When incisal wear classified as slight/none, the straight-line access was plotted on the facial 65.9%. 2. Degree of curvature of main canal was straight or almost straight, and only 10% in buccolingual direction had a degree of curvature greater than 20 degrees and 5.5% in mesiodistal direction had. 3. In section method, canal configuration analysis showed that 51% of the specimen classified as type I, 27% as type II, 12% as type III, 10% as type IV. For theses setions with two canals, the incidence of an isthmus was 36.7%, 64.3%, 79.2%, 96.3%, 97.4%, 97.6% at each level and highest in 3~5mm sections. 4. In clearing method, canal configuration analysis showed that 74% of the specimen classified as type I, 11% as type II, 6% as type III, 9% as type IV. These results suggested that traditional access from lingual should be moved as far toward the incisal as possible to locate and debride the lingual canal and root canal system should be cleaned, shaped completely and obturated three dimensionally for successful endodontic treatment.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.4 no.1
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• pp.11-19
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• 2008

Groundwater flow in confined aquifer and heat transport in underground geologic media are using same governing equation(line source) like well fuction. Therefore the conventional slope method using only later data obtained from in-situ thermal response test to determine the thermal conductivity of vertical geothermal heat exchanger(GHEX) is basically identical with one of Theis straight line method of aquifer test under artesian condition. In case that the pumping rate(Q, $m^3$/d) and drawdown(s,m) which are used for input data of existing hydrogeologic computer programs for aquifer test are replaced and converted to supplying heat energy per unit length of bore hole(Q/L,w/m or Kcal/h.m) and temperatures (T,$^{\circ}C$)measured at in and out-let of GHEX as in put data respectively, thermal conductivity around geothermal heat exchanger can be easily estimated without any special modification of the existing hydrogeologic computer program. Two numbers of time series temperature variation data obtained from in situ geothermal response test are analized using Theismethods(standard curve and straight line method) by using existing aquifer test program and conventional Slope method proposed by ASHRAE. The results show that thermal conductivity values estimated by two straight methods are identical and the difference of estimated values between standard curve methods and Slope method are also within acceptable ranges. In general,the thermal conductivity estimated from Theis straight linemethod gives more accurate value than the one of Slope method due to that Slope method uses only visual matching otherwise Theis method uses automatic curve matching estimation with reducing RSS.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.11
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• pp.898-906
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• 2014

This paper presents a reduction method for a straight-line path error of a flexible beam deploying from a rotating rigid hub. Previous studies discussed about only vibration phenomena of flexible beams deploying from rotating hubs; however, this study investigates a vibration reduction of a rotating beam with variable length. The equation of motion and associated boundary conditions are derived for a flexible beam deploying from a rotating rigid hub, and then they are transformed to a variational equation. By applying the Galerkin method, the discretized equations are obtained from the variational equation. Based on the discretized equations, the dynamic responses of a rotating/deploying beam are analyzed when the beam end has a straight line motion. A reduction method for the trajectory error is proposed, using the average length of a rotating/deploying beam. It is shown that the proposed method is able to reduce the residual vibration of a rotating/deploying beam.