• Journal of the Korean Society for Precision Engineering
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• v.19 no.5
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• pp.56-63
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• 2002

A new model utilizing a transfer function is introduced in the present paper for analizing motion errors of hydrostatic tables. Relationship between film reaction force in a single hydrostatic pad and form error of a guide rail is derived at various spacial frequencies by finite element analysis, and it is expressed as a transfer function. This transfer function clarifies so called averaging effect of the oil film quantitively. For example, it is found that the amplitide of the film reaction farce is reduced as the spacial frequency increases or relative width of the pocket is reduced. Motion errors of a multiple pad table is estimated from transfer function, geomatric relationship between each pads and form errors of a guide rail, which is named as Transfer Function Method(TFM). Calculated motion errors by TFM show good agreement with motion errors calculated by Multi Pad Method, which is considered entire table as an analysis object. From the results, it is confirmed that the proposed TFM is very effective to analyze the motion errors of hydrostatic tables.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.2
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• pp.64-70
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• 2003

A new method using a transfer function is introduced in the present paper for analyzing the motion errors of hydrostatic bearing tables. The relationship between film reaction force in a single-side hydrostatic pad and the form error of guide rail is derived at various spatial frequencies by finite element analysis, and it is expressed as a transfer function. This transfer function clarifies so called 'the averaging effect of an oil film' quantitively. It is found that the amplitude of film force is reduced as the spatial frequency increases or the relative width of the pocket is reduced. The motion errors of a multi pad type table are estimated using a transfer function, the form errors of a guide rail and the geometric relationship between the pads. The method is named as the Transfer Function Method (TFM). The motion errors calculated by the TFM show good agreement with the motion errors calculated by the Multi Pad Method considering the entire table as an analysis object. From the results, it is confirmed that the proposed TFM is very effective to analyze the motion errors of hydrostatic tables.

• International Journal of High-Rise Buildings
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• v.5 no.2
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• pp.95-103
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• 2016

One of the key problems in the design of high-rise commercial complex is how to guide reasonable pedestrian distribution in commercial space. In this study, pedestrian distribution in three high-rise commercial complexes in Shanghai and Hong Kong was studied using spatial configuration analysis software Space Syntax and quantification of physical elements in commercial spaces, such as functional attractiveness, entrances, escalators, level variations and passage width. Additionally, in an attempt to integrate functions with spatial integration and spatial depth, two combination variables, the spatial coefficient of function (IF) and spatial depth coefficient of function (F/D), were proposed. The results of the correlation analysis and multiple regression analyses reflected the following: (1) Regarding the influence on pedestrian distribution, there was a synergistic and complementary relationship between function and space; (2) The comprehensive flow distribution analytic model could successfully interpret flow distribution in high-rise commercial complexes and its R Square ranged up to about 70% in the three cases; (3) The spatial coefficient of function (IF) and spatial depth coefficient (F/D) could effectively integrate functions and spatial configuration, which could help close the gap between over-emphasis on function in commercial research and the lack of consideration of function in space-syntax analysis.

• Korean Journal of Cleft Lip And Palate
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• v.2 no.1_2
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• pp.5-14
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• 1999

The aim of treatment of cleft lip and palate is to correct the cleft and associated problems surgically and thus hide the anomaly so that patients can lead normal lives. This correction involves surgically producing a face that does not attract attention, a vocal apparatus that permits intelligible speech, and a dentition that allows optimal function and esthetics. In neonatal periods, gross distortion of tissues surrounding the cleft requires considerable effort and time due to post operative functional defect and scarring and induces milk feeding problem, malocclusion of deciduous or permanent dentition, congenital missing teeth, skeletal dysplasia. The occurrence of a cleft deformity is a source of considerable shock to the parents of an afflicted baby, and the most appropriate approach is very important things. Thus we tried to analysis of dental arch, shape and size of deformity in cleft patients. The results were obtained as follows. 1. When the cast measurements of UCLP subjects at first visit it was found that the mean length was 9.29mm at the alveolar cleft width, also that was 11.7mm at the anterior width and 14mm at the posterior cleft width. 2. Comparison of UCLP group at first visit and just lip surgery, it was found that the older group showed a insignificant reduction in the width of the cleft in the alveolar, canine, and tuberosity regions. 3. The maxillary casts of the UCLP group at 6 months differ Significantly from those of the at 3 months in both length and width. but there was no statistical difference except anterior ridge length of nonclefted site. 4. Comparison at 6 months and 18 months, there was a greater change in length of the alveolar cleft width, intercanine width, and anterior cleft width. Maxillary arch became wider at both the canine region and intertuberosity region. also posterior anteroposterior length was increased but anterior AP length was decreased from 8.1mm to 7.7mm. There was meaningful increase at intertuberosity length; however, a significant reduction in width t-t'

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.413-422
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• 2011

An improved split-beam transducer for a 50 kHz fish-sizing echo sounder was developed. The main objective of this study was to minimize the side lobe level in the beam pattern and the distance between acoustic centers for adjacent transducer quadrants in the geometrical arrangement of array elements while maintaining a given number of transducer elements and beam width. To achieve these goals, a 32-element planar array transducer ($6{\times}6$ array with one element in each corner missing) was designed using the Dolph-Chebyshev shading function to suppress side lobes in the array beam pattern and fabricated by arranging the inter-element spacing to be substantially equal to half the wavelength using the transducer element of 0.4 times the wavelength in diameter. The performance characteristics of this split-beam transducer were evaluated in the experimental water tank of $5m{\times}5m{\times}6m$ (length${\times}$height${\times}$width). In this study, the design goal of the beam width and side lobe level for transmitting a beam pattern was initially set at $21^{\circ}$ and -30 dB, respectively. However, the measured beam width at 3 dB was $21^{\circ}$ in both directions with side lobe levels of -24.7 dB in the horizontal plane and -25.6 dB in the vertical plane. The averaged beam width at -3 dB of the receiving beam patterns for four receiving quadrants was $31.4^{\circ}$. The transmitting voltage response was 161.5 dB (re $1{\mu}Pa$/V at 1 m) at 50.23 kHz with a bandwidth of 2.16 kHz, and the averaged receiving sensitivity for four receiving quadrants was -178.13 dB (re 1 V/${\mu}Pa$) at 49.8 kHz with a bandwidth of 2.64 kHz.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.4
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• pp.321-327
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• 2017

In this study, to investigate the shape of the back bead as a weld quality parameter and to select the optimal condition of the root-pass TIG welding of a horizontal butt-joint, an experimental design and the response surface method (RSM) have been employed. Three parameters are used as input variables, which include the base current, peak current, and welding speed. The back bead width is selected as an output variable representing the weld quality, the target value of the width is 5.4 mm. Conducting the experiments according to the Box-Behnken experimental design, a $2^{nd}$ regression model for the back bead width was made, and the validation of the model was confirmed by using the F-test. The desirability function was designed through the nominal-the-best formula for the appropriate back bead width. Finally, the following optimal condition for welding was selected using the RSM: base current of 0.9204, peak current of 0.8676, and welding speed of 0.3776 in coded values. For verification, a test welding process under the optimal condition was executed and the result showed the back bead width of 5.38 mm that matched the target value well.

• Archives of Craniofacial Surgery
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• v.22 no.2
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• pp.78-84
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• 2021

Background: Facial feminization surgery and malarplasty require information concerning facial features in the malar area. Such information varies as a function of sex and race. The objectives of this study aimed to quantitatively evaluate the location of malar prominence across sexes in the Southeast Asian population, and identify sex-specific differences in malar prominence using a combination of two-dimensional (2D) computed tomography (CT) and three-dimensional (3D) CT. Methods: The location of malar prominence was evaluated in 101 Thai adults, consisting of 52 men and 49 women. This study used both 2D CT and 3D CT to achieve greater accuracy, in which 2D CT was used to measure malar distance, malar summit width, facial width, and malar summitto-facial width ratio whereas 3D CT was used to evaluate the positional relationship between the zygomatic summit and four reference points of the zygoma. Results: The malar summit was positioned more laterally in males (p< 0.01) and was more projected in females (p= 0.01). The other 2D-parameters were wider in males. The ratio between the malar summit width and facial width showed similar results for both sexes. The vertical dimension did not show any statistically significant differences; however, a higher summit position was observed in males. Conclusion: The zygomatic summit is positioned more laterally in males and is more projected in females. However, the ratio was similar, which indicates that the male cranium is larger in size. Based on the results in this study, when facial feminization surgery or malarplasty is performed on a Southeast Asian patient, the malar bone should be reduced horizontally and moved forward for better outcomes.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.339-346
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• 2006

The purpose of this study is to suggest a method to quantitatively predict long-term deformation of walls under an axial load concentrated to a part of the whole width. Four wall specimens were tested and three-dimensional finite element analyses were performed for these specimens. The finite element models established in this study were verified from the test results. On the basis of this verification, analysis parameters were selected considering various dimensions of walls and sectional area that a concentrated load is acting on, and finite element analyses for these parameters were carried out. The concept of the effective width coefficient was newly introduced as a method to predict the long-term behavior of walls, and a function that is able to optimally fit the effective width coefficients calculated from the analysis results for the selected parameters was found from regression analysis. The found function can be conveniently used in practice to predict the long-term behavior under loads concentrated to a local area of the whole width of walls.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.4
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• pp.95-104
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• 2006

The DMZ is a 248km long thin green line which has various landscapes of fields, hills and mountains. This study focused on western part of DMZ and vicinity which consist of abandoned rice paddy, wetlands and fields. The main purpose of this study is to detect the vegetation vitality from the western part of MDL to DMZ vicinity and identify and quantify ecological buffer(ecotone) width adopting logistic function derived from 'Vegetation Index-distance curve' using an Landsat ETM+ image acquired on June of 2002. Green leaf vegetation was quantified to identify the ecotone buffer in western DMZ and vicinity(civilian control area: CCA) using Transformed Vegetation Index(TVI) which is one of common measurement among various indices. Vegetation measurement from Military Demarcation Line(MDL) to vicinity area was investigated at 500m intervals to 10kms of southern and northern part of western DMZ and vicinity. The Logistic function models the sigmoid curve of growth with three stages of growth of initial competition and maturity. In the TVI-distance logistic curve, the maturity is high vegetation vitality, the competition is vitality changing, and the initial is low vitality. In the TVI-distance curve, maturity area of high TVI value is core area for ecological conservation, and the competition area between inflection points can be an ecotone(ecological buffer). In case of southern part, maximum TVI value is 221.92 and minimum is 207.16, and maximum TVI of northen part is 215.32 and minimum is 188.35. That means forest devastation of north Korean part of DMZ and vicinity is severer than that of south Korea. The width of core area for ecological conservation is 2,311m, and ecotone in the southern part is 5,339m, so minimum width from MDL for ecological conservation can be computed as 7,651m. In case of Northern part, the width of core area is 1,841m, and ecotone buffer is 5,014m, so ecological conservation width can be estimated as 6,855m. In case of northen part, width of estimated core area is less than that of DMZ width, which means ecological disturbance is very severe in northern part of western DMZ.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.255-258
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• 1996

This paper describes a DC voltage controller for the DC power supply which is constructed using the full-bridged MOS-FET DC-to-RF power inverter and rectifier. The full-bridged MOS-FET DC-to-RF inverter consisting of four MOSFET arrays and an output power transformer has a control function which is able to control the RF output power when the widths of the pulse voltages which are fed to four MOS-FET arrays of the fall-bridged inverter are changed using the pulse width control circuit. The power conversion efficiency of the full-bridged MOS-FET DC-to-RF power inverter was approximately 85 % when the duty cycles of the pulse voltages were changed from 30 % to 50 %. The RF output voltage from the full-bridged MOS-FET DC-to-RF inverter is fed to the rectifier circuit through the output transformer. The rectifier circuit consists of GaAs schottky diodes and filters, each of which is made of a coil and capacitors. The power conversion efficiency of the rectifier circuit was over 80 % when the duty cycles of the pulse voltages were changed from 30 % to 50 %. The output voltage of the rectifier circuit was changed from 34.7V to 37.6 V when the duty cycles of the pulse voltages were changed from 30 % to 50 %.