• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2005년도 춘계학술대회 논문집
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• pp.40-44
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• 2005

For an increasing interest on environment and a reinforcement of regulation, reverse supply chain is getting more interest recently In this study, reverse supply chain model of the automobile industry is designed using system dynamics. Using this model, an enterprise can do various analysis to get better understanding in strategic and operational aspect. The impact on supply chain which is caused by the variation of remanufacturing rate and recycle rate as time changes can be analyzed. Also environment image of the enterprise can be analyzed in quantitative manner to make it easy to set up own strategic plan.

• 한국IT서비스학회지
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• 제11권4호
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• pp.215-231
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• 2012

It is well known that SaaS(Software as a Service) changeover gives several advantages to organization. One of the advantages is the cost reduction effect of IT resources as well as IT human resources. Another one is the curtailment of software development workload in the field of informatization promotions. Nonetheless, it is hard to find comparison cases regarding the quantitative measurement of the introduction of SaaS before and after. Accordingly, when the Government IDC tries to adopt SaaS, it absolutely needs the empirical study whether SaaS is cost-effectiveness or not. In this study, we focus on variation in the Government administration common tasks, processes and labor costs. Using the Man-Month(MM) estimation methods, We verify that how much TCO(Total Cost of Ownership) is reduced per year.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2006년도 학술발표회 논문집
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• pp.351-357
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• 2006

In this study, quantitative sensitivity analysis on rockfill material influencing the dam crest displacement of Concrete-Faced Rockfill Dam(CFRD) subjected to earthquake loading was carried out. The purpose of this study is to indicate the most important input parameter and to show the quantitative variation of displacement at the crest of CFR type dam during earthquake loading with this input parameter. From the sensitivity analysis, it was found that the crest displacement of CFR type dam subjected to dynamic loading was absolutely affected by the shear modulus of rockfill material and the effect of friction angle of it was negligible. This relative difference of sensitivity was more outstanding in case of crest settlement than in case of crest horizontal displacement. Also, it was found that the extent of effect of shear modulus on the displacement at the crest of CFRD due to dynamic loading decreased as maximum amplitude of input acceleration increased.

• Current Optics and Photonics
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• 제7권5호
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• pp.537-544
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• 2023

Differential phase contrast (DPC) microscopy, a central quantitative phase imaging (QPI) technique in cell biology, facilitates label-free, real-time monitoring of intrinsic optical phase variations in biological samples. The existing DPC imaging theory, while important for QPI, is grounded in paraxial diffraction theory. However, this theory lacks accuracy when applied to high numerical aperture (NA) systems that are vital for high-resolution cellular studies. To tackle this limitation, we have, for the first time, formulated a nonparaxial DPC imaging equation with a transmission cross-coefficient (TCC) for high NA DPC microscopy. Our theoretical framework incorporates the apodization of the high NA objective lens, nonparaxial light propagation, and the angular distribution of source intensity or detector sensitivity. Thus, our TCC model deviates significantly from traditional paraxial TCCs, influenced by both NA and the angular variation of illumination or detection. Our nonparaxial imaging theory could enhance phase retrieval accuracy in QPI based on high NA DPC imaging.

• 치과방사선
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• 제29권1호
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• pp.33-42
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• 1999

Geometrically standardized dental radiographs were taken. We prepared Digital Cu-Equivalent Image Analyzing System for quantitative assessment of mandible bone. Images of radiographs were digitized by means of Quick scanner and personal Mcquintosh computer. NIH image as software was used for analyzing images. A stepwedge composed of 10 steps of 0.1mm copper foil in thickness was used for reference material. This study evaluated the effects of step numbers of copper wedge adopted for calculating equation. kVp and exposure time on the coefficient of determination(r²)of the equation for conversion to Cu-equivalent image and the coefficient of variation and Cu-Eq value(mm) measured at each copper step and alveolar bone of the mandible. The results were as follows: 1. The coefficients of determination(r²) of 10 conversion equations ranged from 0.9996 to 0.9973(mean=0.9988) under 70kVp and 0.16 sec. exposure. The equation showed the highest r was Y=4.75614612-0.06300524x +0.00032367x² -0.00000060x³. 2. The value of r² became lower when the equation was calculated from the copper stepwedge including 1.0mm step. In case of including 0mm step for calculation. the value of r showed variability. 3. The coefficient of variation showed 0.11, 0.20 respectively at each copper step of 0.2, 0.1mm in thickness. Those of the other steps to 0.9 mm ranged from 0.06 to 0.09 in mean value. 4. The mean Cu-Eq value of alveolar bone was 0.14±0.02mm under optimal exposure. The values were lower than the mean under the exposures over 0.20sec. in 60kVp and over 0.16sec. in 70kVp. 5. Under the exposure condition of 60kVp 0.16sec.. the coefficient of variation showed 0.03. 0.05 respectively at each copper-step of 0.3, 0.2mm in thickness. The value of r² showed over 0.9991 from both 9 and 10 steps of copper. The Cu-Eq value and the coefficient of variation was 0.14±0.01mm and 0.07 at alveolar bone respectively. In summary. A clinical application of this system seemed to be useful for assessment of quantitative assessment of alveolar provided high coefficient of determination is obtained by the modified adoption of copper step numbers and the low coefficient of variation for the range of Cu-Equivalent value of alveolar bone from optimal kVp and exposure time for each x-ray machine.

• 대한지역사회영양학회지
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• 제7권4호
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• pp.484-494
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• 2002

This study was conducted to validate the semi-quantitative food frequency questionnaire that was developed to assess the intakes of fatty acids, as well as energy, carbohydrates, fat, protein, minerals and vitamins in Korean adults. The validity of the semi-quantitative food frequency questionnaire was tested on 78 subjects (31 men,47 women) aged 34 to 66 years. The semi-quantitative food frequency questionnaire included 93 food items and was validated on two 3-day dietary records. The mean intakes and the Spearman Correlation Coefficients between the semi-quantitative food frequency questionnaire and the two 3-day dietary records were analyzed for each nutrient and food group level. The mean nutrient intakes obtained from the semi-quantitative food frequency questionnaire were estimated to be greater than those of the two 3-day dietary records. The Spearman Correlation Coefficients between the energy-adjusted nutrient intakes from the semi-quantitative food frequency questionnaire and the two 3-day dietary records ranged from 0.24 for polyunsaturated fatty acids to 0.55 for fat in men and from 0.29 for polyunsaturated fatty acids to 0.55 for saturated fatty acids in women, respectively. The Spearman Correlation Coefficients for food intake ranged from 0.11 for teas and beverages to 0.58 for grains and their products in men,-0.04 for potatoes and starches to 0.73 for milk and dairy products in women. Foods consumed regularly had lower intra-person variation and tended to have higher observed correlation coefficients. These results indicate that the semi-quantitative food frequency questionnaire is a useful tool for estimating nutrient intakes, particularly of total fat and saturated fatty acid intakes.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1997년도 특별강연 및 춘계학술발표 개요집
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• pp.35-38
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• 1997

In order to investigate quantitative behavior of galvanic corrosion in the weld joint between stainless steel and carbon steel, electrochemical polarization experiments are performed for various pH, water temperature with boric acid concentration 4000ppm. The corrosion rate of stainless steel was almost independent of the variation of pH. The significant corrosion rates of carbon steel and the weld joint of carbon-carbon steel were observed at pH 4. The corrosion rates in the weld joint of the carbon-stainless steel were observed depending on the variation of pH level.

• 한국가시화정보학회지
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• 제5권1호
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• pp.22-29
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• 2007

In the present study, naturally generated bubbles were investigated to be sure if they could be adopted as the tracer for PIV techniques. The bubble can be grown from the nuclei melted in the water of tunnel and the size of bubbles is changed through the variation of tunnel pressure. Since the trace ability and appropriate size of tracer are so important for PIV techniques, the characteristics of bubbles as tracer are revealed in terms of trace ability and bubble size with the variation of flow speed and tunnel pressure in this study. In addition, PIV measurements of (low behind a rotating propeller are conducted to confirm the trace ability of bubbles even in a highly vortical flow.

• 한국환경보건학회지
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• 제30권5호
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• pp.427-431
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• 2004

The calcination characteristics of the waste Corbicula Japonica and Ostrea virginjca shell were examined for the future use as desulfurization sorbent. The weight variation was measured according to thermal-decomposition using TGA and observed variation of the phase. The qualitative and quantitative analysis of the sample were performed using XRD and the structural analysis, SEM. The results of TGA and XRD experiments showed that the almost all of the raw samples Corbicula Japonica and Ostrea virginjca were changed from calcite to lime by firing and calcination reaction. The result of SEM experiment showed that the plate type of the raw sample was changed to circle type, so the surface area ratio was increased. Above results suggested that waste Corbicula Japonica and Ostrea virginjca were usable in the viewpoint of the reuse of resource and the decrease of environmental pollution.

• 한국정보전자통신기술학회논문지
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• 제9권6호
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• pp.546-552
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• 2016

We present a quantitative evaluation of an algorithm for model-based face recognition. The algorithm actively learns how individual faces vary through video sequences, providing on-line suppression of confounding factors such as expression, lighting and pose. By actively decoupling sources of image variation, the algorithm provides a framework in which identity evidence can be integrated over a sequence. We demonstrate that face recognition can be considerably improved by the analysis of video sequences. The method presented is widely applicable in many multi-class interpretation problems.