• Archives of Plastic Surgery
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• 제51권2호
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• pp.169-181
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• 2024

Background With the advent of cranial orthoses as therapeutic medical devices for the treatment of severe positional head deformities in Japan, an increasing number of patients are being treated with them. However, assessing the effectiveness of a treatment is often difficult due to the use of different metrics. This study aimed to evaluate the effectiveness of cranial orthoses for deformational plagiocephaly using two- (2D) and three-dimensional (3D) evaluation metrics. Methods We conducted a retrospective study of infant patients with deformational plagiocephaly who underwent cranial orthosis treatment. We evaluated the severity of deformational plagiocephaly using cranial asymmetry (CA) and the cranial vault asymmetry index (CVAI) as 2D metrics, and anterior and posterior symmetry ratios as 3D metrics. The patients were divided into 24 subgroups based on the initial severity of each outcome and their age at the start of treatment. We analyzed the changes in outcomes and correlations within improvements across the age and severity categories. Results Overall, 1,038 infants were included in this study. The mean CA, CVAI, and anterior and posterior symmetry ratios improved significantly after cranial orthosis treatment. The improvement in each score was greater in patients with more severe initial deformities and in those who underwent treatment at a younger age. Conclusion Cranial orthosis treatment was effective in correcting deformational plagiocephaly in infants, as demonstrated by improvements in both 2D and 3D metrics. Patients with more severe initial deformities and those who underwent treatment at a younger age showed greater improvement.

• 대한기계학회논문집A
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• 제26권1호
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• pp.121-130
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• 2002

Clean stockers are being used by semiconductor and TFT-LCD manufacturers to store and buffer work in process. Since an important function of a stocker is to keep the contained material clean. The only way to keep the stored product clean is to provide constant clean airflow the product and through stocker, The airflow across the product prevent contamination from settling on the product. Up to now, stocker typically have been configured to receive their laminar airflow from fan filter units that are located on the side of the stocker This type of stocker may have such problems as complexity of structure, increment of temperature, mechanical vibration, initial investment and running cost. In this study, In order to solve the above mentioned problems, new air control system in stocker is proposed, which is to control open ratios of exits that are located on the side of the stocker without fan filter units. Open ratios of exits need to be optimized for the same quantities of airflow in each exit. In this study, static pressure regain was used for the analysis of the open ratios of exits theoretically and Blue Ridge Numerics FEM software, CFDesign, was used fur simulating airflow in stocker. As a result, Open ratios of exits important to provide constant clean airflow can be obtained by the analysis of static pressure regain and was verified by simulation results. Therefore, new air control system in stocker can be used by the semiconductor and TFT-LCD manufacturers.

• Structural Engineering and Mechanics
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• 제58권2호
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• pp.347-378
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• 2016

Within the scope of the plane-strain state, by utilizing the three-dimensional linearized theory of elastic waves in initially stressed piezoelectric and elastic materials, Lamb wave propagation and the influence of the initial stresses on this propagation in a sandwich plate with pre-stressed piezoelectric face and pre-stressed metal elastic core layers are investigated. Dispersion equations are derived for the extensional and flexural Lamb waves and, as a result of numerical solution to these equations, the corresponding dispersion curves for the first (fundamental) and second modes are constructed. Concrete numerical results are obtained for the cases where the face layers' materials are PZT-2 or PZT-6B, but the material of the middle layer is Steel (St) or Aluminum (Al). Sandwich plates PZT-2/St/PZT-2, PZT-2/Al/PZT-2, PZT-6B/St/PZT-6B and PZT-6B/Al/PZT-6B are examined and the influence of the problem parameters such as piezoelectric and dielectric constants, layer thickness ratios and third order elastic constants of the St and Al on the effects of the initial stresses on the wave propagation velocity is studied.

• 천문학회보
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• 제42권2호
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• pp.64.2-64.2
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• 2017

The Population III (Pop III) stars are thought to be massive. If massive Pop III stars form binary system and they experience mass transfer via the Roche lobe overflow, this may significantly change the properties of the system. For example, mass transfer in such system may shorten the period of the system, forming short period binary black hole (BBH) system, which is the most promising candidate for recently detected gravitational wave radiation sources. Also, there is an expectation that due to the stripped envelope of donor star by mass transfer, this system can play a significant role in the cosmic reionization by emitting more UV photons. However, this outcome highly depends on the initial properties of the system. We perform grid calculation on Pop III binary models with various initial primary masses (20 ~ 100 solar mass), initial separations, and initial mass ratios (q = 0.5 ~ 0.9). We find that 1) in most cases binary models show no increase in the number of ionizing photons and 2) formation of short period BBH system via mass transfer is highly unlikely.

• Geomechanics and Engineering
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• 제24권3호
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• pp.295-305
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• 2021

In this study, design charts for estimating consolidation settlement are proposed according to finite strain consolidation theory using a nonlinear constitutive relationship equation. Results of parametric sensitivity analysis shows that the final settlement, initial height, and initial void ratio exerted the greatest effect, and the coefficients of the void ratio-effective-stress. Proposed design charts were analyzed for three regions using a representative constitutive relationship equation that enables major dredged-reclaimed construction sites in Korea. The regional design charts can be calculated accurately for the final settlement because it is applied directly to the numerical analysis results, except for reading errors. A general design chart applicable to all marine clays is proposed through correlation analysis of the main parameters. A final self-weight consolidation settlement with various initial void ratios and initial height conditions should be estimated easily using the general design chart and constitutive relationship. The estimated final settlement using the general design chart is similar to the results of numerical analysis obtained using finite strain consolidation theory. Under an overburden pressure condition, design charts for estimating consolidation settlement are proposed for three regions in Korea.

• 상하수도학회지
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• 제19권4호
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• pp.446-454
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• 2005

An economic treatment method to remove oxidized nitrogen from wastewater is biological denitrification with organic matters. Several organics can be used, however, methanol is commonly used. When methanol is provided, M:N (Methanol to Nitrogen) ratio is used to define methanol demand for denitrification. In this study, two artificial wastewaters were provided to a biological system to evaluate denitrification performance. Differences of influent total CODcr from effluent soluble CODcr were converted to methanol equivalent and oxidized nitrogen difference between influent and effluent were converted to nitrate equivalent to define M:N ratios. Modes I, II, III, I-1 and IV showed 5.1, 2.7, 3.3, 2.3 and 2.6 of M:N ratios, respectively. Since denitrifying microorganisms had to build a new metabolic system for methanol and influent organics, initial operation mode, Mode I, required more methanol and this resulted in high M:N ratios compared with later operation mode, Mode I-1. Salt in influent did not show inhibitory effects on denitrfication, although this was believed to increase effluent SS and soluble CODcr concentrations in Mode III, I-1 and IV, respectively. The concentrations of effluent soluble $COD_{Mn}$ did not changed much with influent salt.

• 신재생에너지
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• 제10권3호
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• pp.39-46
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• 2014

The performances of three different types of photovoltaic (PV) module technologies namely, copper-indium-diselenide (CIGS), mono-crystalline silicon (mo-Si) and amorphous silicon (a-Si) have been comparatively studied in the grid-connected system for more than a year under the tropical monsoon climate of Thailand. The yields, performance ratios and system efficiencies for the respective PV module technologies have been calculated and a comparison is presented here. The performance ratios of the initial operation year for CIGS showed highest among the compared technologies under Thailand climate conditions by marking 97.0% while 89.6% for a-Si and 81.5% for mo-Si. Although mo-Si has shown highest efficiencies all over the period, under the testing conditions, the operating efficiency of mo-Si was down-graded from its reference value mainly due to high operating temperature and the efficiency of the tested CIGS module was also found as high as that of mo-Si in the study. Accordingly, outdoor assessment shows that CIGS modules have demonstrated high performance in terms of yields and performance ratios in Thailand climate conditions.

• Structural Engineering and Mechanics
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• 제42권2호
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• pp.131-152
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• 2012

In-plane free vibrations of circular beams with stepped cross-sections are investigated by using the exact analytical solution. The axial extension, transverse shear deformation and rotatory inertia effects are taken into account. The stepped arch is divided into a number of arches with constant cross-sections. The exact solution of the governing equations is obtained by the initial value method. Several examples of arches with different step ratios, different locations of the steps, boundary conditions, opening angles and slenderness ratios for the first few modes are presented to illustrate the validity and accuracy of the method. The effects of the geometric parameters on the natural frequencies are investigated in details. Several examples in the literature are solved and the results are given in tables. The agreement of the results is good for all examples considered. The mode transition phenomenon is also observed for the stepped arches. Some examples are solved also numerically by using the commercial finite element program ANSYS.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.123-128
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• 2005

This study purposes to increase the energy-saving effects by reducing excessive intensity of radiation of artificial lighting through analyzing daylight incident A photosensor sends amounts of detected luminous flux to digital control unit(DCU) as a signal and then, it can decide dimming ratios, received a proper dimming signal from DCU. Generally it Is effective to control artificial lighting with the different control ratio of each row by setting a photosensor as same numbers and rows as artificial lighting. However, it is ineffective to do in initial costs of systems aspect in offices. As a result of grasping the distribution of daylight previously, we can dim different dimming ratios to each row of artificial lighting by a single photosensor.

• 전기의세계
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• 제25권6호
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• pp.74-80
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• 1976

The temperature rise of the mortars while are being irradiated by ultrasonic waves and immersed in a liquid medium, are measured. The mixing ratios of sand to cement are varied for the different mortars. The results of the experiment are as follows, 1. The temperature rise of the mortar is decreased as themixing ration (S/C) is increased. 2. Thd temperature rise of the specimen is increased as its length is increased. 3. The surface conditions, either smooth or rough, may not have much influence on the temperature rise of the mortar. 4. The initial slope of temperature rise may not have much effect of the viscosity of liquid. The results, describes above, appear well coincide with the theory that the temperature rise is attributed mainly to the absorption heating. Since the absorption heating of the mortars varies with the mixing ratios of sand to cement, the strength of them would be estimated by means of irradiation of ultrasonic waves on the specimen.