• Animal cells and systems
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• v.4 no.2
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• pp.131-140
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• 2000

The pattern of variations in cone sex ratio and pollen traits such as pollen number and size was examined for two years in populations of red pines In Korea. We evaluated; (1) the relationship between tree size and cone sex ratio, (2) the relationship between year and cone sex ratio, and (3) the relationship between cone sex ratio and pollen traits. Larger trees in height and circumference at breast height produced more male as well as female cones. However, cone sex ratio was independent of these plant sizes. Across the two populations, both female cone numbers per tree and male cone numbers per new shoot increased 2.2 and 1.2 times, respectively, in 1999 compared to 1998, while the yearly pattern of male cone-bearing shoots per tree differed significantly between populations. Thus, cone sex ratio varied significantly between years in one of the two populations. Pollen traits such as the number of pollen grains and diameter did not vary significantly among populations. Pollen diameter and grain numbers per male cone were significantly negatively correlated with the cone sex ratio in two populations and one population, respectively. Trees which stopped female cone production in the first year and those which produced female cones in both years differed in the cone sex ratio and pollen size in the second year. The long duration of one reproductive episode and the potential of masting in red pines emphasize the need to conduct long-term studies on the dynamics of cone production, cone sex ratio, and simultaneous changes in pollen traits in red pines.

• Progress in Medical Physics
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• v.1 no.1
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• pp.109-122
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• 1990

A method of making inserts for shaped fields in electron beam therapy on the Mevatron KD 67-7467 Linear Acclerator is introduced. The inserts are made from an alloy called Lipowitz metal. These are designed to fit the inside of the standard Siemens cones. Studies have shown that this method does not adversely affect field flatness. However, if the ratio of shaped field to open field is greater than about 70%, the output dose is significantly changed by the inserts. Because the cone ratios for the fields do not follow the open cone ratio curves on the Mevatron KD 67-7467, we separated the cone ratio suggested by Biggs into two parts, the insert ratio and the cone factor. The dosimetry for these shaped beams has been investigated extensively.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.1
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• pp.10-16
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• 2010

Mail centers are essential postal facilities that sort and dispatch postal items, and should be operated efficiently to provide customers high quality postal services. So the efficiency analysis of mail centers should be performed in order to induce better operation. But current performance evaluation system has 95 percent of predetermined and weighted non-quantitative indices. There is need to introduce objective efficiency measurement methodology. The main objectives of this study was to analyze the efficiency of 24 mail centers empirically using cone-ratio DEA and suggest the appropriate cone-ratio method. Consequently, this paper suggests that the cone-ratio DEA model integrating decision-maker's preferences is more desirable for efficiency analysis than that of using transformed data.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.2
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• pp.124-131
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• 2012

본 논문에서는 Cone-ratio 가중치 제약이 DEA 단일 입력, 다중 출력(또는 다중 입력, 단일 출력)에 맞게 constant return을 하는 문제에 적용될 때 효율성을 측정하는 방법에 필요한 특성을 제안하였다. 또한 제안된 특성들을 기반으로 DEA에서의 단일 입력, 이중 출력에 대한 다중 해결 문제의 예시를 제시한 후 Cone-ratio 및 Wong과 Beasley 가중치 제약의 특성들을 도식적으로 비교 설명하였다.

• Restorative Dentistry and Endodontics
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• v.27 no.1
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• pp.66-76
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• 2002

The purpose of this study is to evaluate the effectiveness of customized master cone on apical sealing in various apical size of prepared root canals, that is MAF(Master Apical File) and to know at which apical size the apical leakage is to be significantly reduced using customized master cone. 120 extracted single rooted premolars were divided into four groups according to their apical size(MAF), #30, 40, 50 and 60. And then, each group was subdivided into three in accordance with three obturation methods, lateral condensation with standardized master cone, lateral condensation with chloroform-dipped customized master cone, and continuous wave of obturation technique. Resorcinol-formaldehyde resin was used for the microleakage test of this study. Teeth were sectioned horizontally at 1.5mm(Level 1), 2.5mm(Level 2), and 3.5mm(Level 3) from the anatomical root apex using low speed microtome. All sections were examined under $\times$40 magnification with a stereomicroscope, photographed, and then scanned. With the scanned images, resin-infiltrated area presenting the microleakage was calculated using SigmaScan/Image, and the ratio of leakage to the total root canal area of each group was analyzed statistically(one way ANOVA). The results were as follows ; 1. In groups of MAF #30, there was no significant difference of mean leakage ratio among three obturation methods at all three levels. 2. In groups of MAF #40, the group using lateral condensation with customized master cone had the low-est mean leakage ratio at all three levels, but there was no significant difference among three obturation techniques. 3. In groups of MAF #50, the mean leakage ratio of the group using lateral condensation with standard master cone was the highest among those of three obturation techniques at level 1, and this difference was statistically significant(p<0.05). 4 In groups of MAF #60, the groups using lateral condensation with standard master cone had also the highest mean leakage ratio at all levels, but there was no significant difference at level 1 and 2. At level 3, the leakage of the group using lateral condensation with standard master cone was significantly higher than that of the group using continuous wave of obturation(p<0.05). The results of this study suggested that the obturation method using customized master cone or the continuous wave of obturation is more effective for apical sealing than that using standardized master cone when MAF is larger than ＃50.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3296-3301
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• 2009

The results of PCPT(Pezocone Penetration Test) are widely used for the estimation of the undrained shear strength, for which the empirical cone factors($N_{kt}$, $N_{ke}$, $N_{{\Delta}u}$) need to be obtained at each site. In this study, the cone factors were estimated, for the soils at Bookmyun area in Changwon city, using the undrained shear strengths from the unconfined and UU triaxial compression tests. The parametric studies with plastic index and pore water pressure ratio were performed as well. $N_{kt}$, $N_{ke}$ and $N_{{\Delta}u}$ were estimated in the ranges of 8~40, 7~37, and 1~26 respectively. It was observed that there is a relationship between the cone factors, specially $N_{{\Delta}u}$, and the pore pressure ratio.

• Restorative Dentistry and Endodontics
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• v.30 no.2
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• pp.79-85
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• 2005

The purpose of this study was to evaluate the obturation efficiency of a non-standardized gutta-percha cone in curved root canals prepared with 0.06 taper nickel-titanium instruments. Sixty simulated curved root canals in clear resin blocks were prepared with crown-down technique using 0.06 taper rotary $ProTaper^{TM}$and ProFile (Dentsply-Maillefer) until apical canal was size 30. Root canals were randomly divided into 4 groups of 15 blocks and obturated with cold-laterally compacted gutta-percha technique by using either a non-standardized size medium gutta-percha cone or an ISO-standardized size 30 one as a master cone. Gutta-percha area ratio were calculated at apical levels of 1, 3 and 5 mm using AutoCAD 2000 after cross-sectioning, and the data were analyzed with one-way and two-way ANOVAs and Duncan's multiple range test. Non-standardized size medium cone groups showed significantly higher gutta-percha area ratio than standardized cone groups at all apical levels (p < 0.01). Non-standardized cone groups used significantly less accessory cones than standardized cone groups (p < 0.01).

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.57-60
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• 2011

The spray characteristics according to the recess length of the GCSC injector and the change of momentum flux ratio(MFR) of the gas and the liquid have been examined through high pressure cold flow test using a high pressure chamber. The liquid in this experiment was water, and the gas was nitrogen. The spray images were taken by a back-lit strobe imaging technique. Results showed that the spray was a wide hollow cone at the lower MFR(liquid velocity was fixed) and the spray became a narrow solid cone as the MFR was increased. And the injector with short recess length produced a narrow solid cone at the higher MFR.

• Structural Engineering and Mechanics
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• v.46 no.1
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• pp.39-51
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• 2013

An extremum method is presented to predict the wrinkling characteristics of the inflated cone in bending. The wrinkling factor is firstly defined so as to obtain the wrinkling condition. The initial wrinkling location is then determined by searching the maximum of the wrinkling factor. The critical wrinkling load is finally obtained by determining the ratio of the wrinkling moment versus the initial wrinkling location. The extremum method is proposed based on the assumption of membrane material of beam wall, and it is extended to consider beam wall with thin-shell material in the end. The nondimensional analyses show that the initial wrinkling location is closely related to the taper ratio. When the taper ratio is higher than the critical value, the initial wrinkles will be initiated at a different location. The nondimensional critical wrinkling load nonlinearly increases as the taper ratio increases firstly, and then linearly increases after the critical taper ratio. The critical taper ratio reflects the highest load-carrying efficiency of the inflated cone in bending, and it can be regarded as a measure to optimize the geometry of the inflated cone. The comparative analysis shows fairly good agreement between analytical and numerical results. Over the whole range of the comparison, the mean differences are lower than 3%. This gives confidence to use extremum method for bending-wrinkling analysis of inflated conical cantilever beam.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.3
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• pp.80-87
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• 2010

The purpose of this paper is to analyze the effects of ethanol blending ratio and fuel temperature in diesel-ethanol blended fuel on the spray-atomization characteristics in a high pressure common-rail injection system. In this work, a diesel fuel and three blended fuels were used as test fuels. Blended fuels were made by blending ethanol with a purity 99.9% to diesel fuel, from 0% to 30%. In order to keep diesel-ethanol blending stability, 5% of biodiesel fuel as volumetric ratio was added into test fuels. The fuel temperature was controled in steps with 40K, from 290K to 370K. Macroscopic spray characteristics were investigated by analyzing the spray tip penetration and spray cone angle through spray images obtained from visualization system. In addition, in order to study microscopic spray characteristics of ethanol blended fuels, the droplet diameter, was analyzed using the droplet measuring system. It is revealed that the spray tip penetration is similar regardless of ethanol blending ratio. As ethanol blending ratio is increased, the spray cone angle becomes wider. It is shown that the spray cone angle is affected by low viscosity and density of ethanol. As the fuel temperature increases, the spray tip penetration and spray cone angle become shorter and narrower respectively. The SMD of ethanol blending fuels is smaller than that of diesel fuel because of low viscosity and surface tension of ethanol.