• Restorative Dentistry and Endodontics
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• v.9 no.1
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• pp.127-132
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• 1983

The purpose of this study was to examine the sealing ability of the vitapex, when used with gutta-percha cone, as a root canal filling material. Fourty five canals from extracted human maxillary and mandibular teeth were randomly selected and instrumented in a conventional method with k-file. After instrumentation and dry the canal with paper points, the canals were divided into three groups and fifteen canals in each group were filled with the following materials; Vitapex, Vitapex in combination with gutta-percha cone, and Gutta-percha cone and Zinc-oxide Eugenol Cement. All the specimens were immersed in 2% methylenblue dye solution and the depth of dye penetration into the canals were evaluated by macroscope at the intervals of 1 day, 2days and 7days. The following results were obtained; 1. All the materials experimented showed varying degrees of dye penetration. 2. The canals filled with Vitapex and Vitapex in combination with gutta perch a cone revealed sudden increase of dye penetration with time passage compared to the canals obturated with Gutta-percha cone and Zinc-oxide eugenol cement. 3. In the canals filled with Vitapex, the mean dye penetration was 1.6mm at 1day, but the specimen exposed to the dye for 7days showed mean dye penetration of 9.2mm. 4. In the canals obturated with Vitapex and gutta-percha cone, the mean dye penetration was 2mm at 1day, 2.2mm at 2days, and 8mm at 7days.

• Journal of the Korean Society of Physical Medicine
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• v.2 no.1
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• pp.73-84
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• 2007

Purpose : The purpose of this study was to determine risk factors and methods in balance assessment associated with fall in older adults. Methods : This article describes many of the tools that can be used to evaluate the physical parameters associated with fall risk in older adults. Results : Composite ratings of performance(Tinetti balance assessment, Guralnik test battery, Berg balance scale, modified-physical performance test) measures the score compounding the balance measure to determine fall risk. Static balance instruments are composed of FICSIT-4 that measures the ability of maintaining foot positions and CTSIB that measures postural stability. Dynamic balance instrument is composed of functional reach test. To measure walking velocity and mobility, 8-foot up-and-go test and walking around two cones are used. We can use 1-RM and to measure muscular strength, isokinetic dynamometery, and 30-second chair stand to measure lower extremity muscle strength. Conclusion : The described instruments are easy to use and widespread. To select and use these tool kits carefully is considered to be helpful in identifying those who are most likely to fall. The final part of the article includes a brief discussion of the potential role of exercise training interventions to improve these physical parameters and prevent falls.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.440-445
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• 2011

This paper presents a new regenerative brake system of electric vehicles that employs a continuous variable transmission(CVT) and a flywheel. The developed device has advantages over existing regenerative brakes from a standpoint of reliability and versatility in actual driving conditions. The system consists of a CVT, two wheels, a flywheel, a coupling and auxiliary powertrain components. The CVT is designed as a combination of two cones and a roller, which causes the velocity difference between the wheel and the flywheel. The power flow of the flywheel system is controlled by the CVT roller and the coupling through step motors. A prototype has been developed and then its performance has been investigated for various operating conditions. Results show that the storage efficiency of the flywheel is much affected by the vehicle's velocity and it is reduced below 20% for high speed, as compared to the 25% efficiency for an ideal condition. The CVT is a primary factor for lowering the flywheel efficiencies due to large friction and slipping between the cone and the roller.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.156-163
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• 2003

In order to investigate the possibility of punching process of brittle material by ball impact, the effects of sealing materials about impact damage of soda-lime glass by small spheres were evaluated experimentally. The using of sealing materials in the development of perfect cone crack was more effective than no using of sealing materials. At the sealing materials condition, in the case of 5mm-thick specimen, Copper and PMMA sealing were more effective in producing a perfect cone formation than the other sealing materials. And in the case of 8mm-thick specimen, Aluminum sealing was most effective in producing a perfect cone formation. The impact velocity range over which perfect cones were formed was influenced by both the thickness of specimen and sealing materials. By a proper selection of sealing materials, the application fur industrial technology for hole (or nozzle) punching process of brittle materials is expected.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.5
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• pp.807-820
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• 1997

This exploratory research was intended to develop and test a slacks pattern based upon conic model. Data came from measurements of photograph of three subjects. Silhouette of slacks was close fit on waist and hip and loose under hip level. This three-dimensional form was modeled with truncated cones. This conic model was truncated by plane of the waist level, the abdomen level, the hip level, the crotch level and the ankle level parallel to the floor. Two models that have differences in back part of the model were tested. Drafted patterns from two models were taken for each subject. Drafted experimental pattern was operated for slacks pattern. The first step was to make sideseam. Parts over crotch level were moved to both sides. And then to make waistdarts. Experimental pattern had two darts each in front and back. Each experimental slacks was evaluated by sensory test to appearance and comfort by five judges. The results can be summarized as follows. 1) Appearance and comfort of experimental pattern were judged to be satisfactory. Especially these patterns were fitted we18 in waist darts front and back. So we evaluated that was proper pattern for slacks. 2) Model 2 was better in appearance than model 1. But Model 1 was more comfortable in non significant difference. This was supposed to be resulted from fit more closely of model 2. 3) considering preceding results, this geometric model based upon truncated cone was applicable for slacks pattern.

• Earthquakes and Structures
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• v.12 no.2
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• pp.153-163
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• 2017

The underlying goal of the present paper is to investigate soil and structural uncertainties on impedance functions and structural response of soil-shallow foundation-structure (SSFS) system using Monte Carlo simulations. The impedance functions of a rigid massless circular foundation resting on the surface of a random soil layer underlain by a homogeneous half-space are obtained using 1-D wave propagation in cones with reflection and refraction occurring at the layer-basement interface and free surface. Firstly, two distribution functions (lognormal and gamma) were used to generate random numbers of soil parameters (layer's thickness and shear wave velocity) for both horizontal and rocking modes of vibration with coefficients of variation ranging between 5 and 20%, for each distribution and each parameter. Secondly, the influence of uncertainties of soil parameters (layer's thickness, and shear wave velocity), as well as structural parameters (height of the superstructure, and radius of the foundation) on the response of the coupled system using lognormal distribution was investigated. This study illustrated that uncertainties on soil and structure properties, especially shear wave velocity and thickness of the layer, height of the structure and the foundation radius significantly affect the impedance functions, and in same time the response of the coupled system.

• Bulletin of the Korean Mathematical Society
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• v.41 no.3
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• pp.483-492
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• 2004

Let : [0, 1] $\times$ [0, $\infty$) $\longrightarrow$ [0, $\infty$) be continuous and a ${\in}$ C([0, 1], [0, $\infty$)),and let ${\xi}_{i}$ $\in$ (0, 1) with 0 < {\xi}$_1$ < ${\xi}_2$ < … < ${\xi}_{m-2}$ < 1, $a_{i}$, $b_{i}$ ${\in}$ [0, $\infty$) with 0 < $\Sigma_{i=1}$ /$^{m-2}$ $a_{i}$ < 1 and $\Sigma_{i=1}$$^{m-2}$ < l. This paper is concerned with the following m-point boundary value problem: $\chi$″(t)＋a(t) (t.$\chi$(t))＝0,t ${\in}$(0,1), $\chi$'(0)＝$\Sigma_{i=1}$ $^{m-2}$ /$b_{i}$$\chi$'(${\xi}_{i}$),$\chi$(1)＝$\Sigma_{i=1}$$^{m-2}$$a_{i}$$\chi$(${\xi}_{i}$). The existence, multiplicity and uniqueness of positive solutions of this problem are discussed with the help of two fixed point theorems in cones, respectively.

• Bulletin of the Korean Chemical Society
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• v.29 no.10
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• pp.1960-1964
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• 2008

The roles of coordinating ligands (TOPO, OA, HDA, and TDPA) for the synthesis of ZnO nanoparticles are investigated. Various shapes (hexagonal cone, hexagonal plate, and rod) and sizes (5-100 nm) of ZnO nanoparticles are prepared in relation to the coordinating ligands. The hexagonal shapes ($\leq$ 100 nm) are synthesized with TOPO and OA, while smaller size nanorods (5 ${\times}$ 30 nm) are with TOPO and TDPA. The relative intensities of two distinctive emission bands centered at 385 and 500 nm, which are related to the exciton and defect states, respectively, depend on the crystal qualities of ZnO nanoparticles affected by the coordinating ligands. The intense UV emissions with the reduced visible emissions are found in the monodisperse nanoparticles such as hexagonal cones and nanorods, suggesting that the monodispersity as well as the crystallinity is closely related to the coordinating ligands. The blue-shift of photoluminescence and absorption edge is observed in the nanorods, because the sizes of the nanorods are in the quantum confinement regime.

• Journal of Korean Society of Forest Science
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• v.99 no.2
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• pp.235-243
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• 2010

Picea jezoensis with several infraspecific taxa is indigenous to Eastern Asia and the Far East of Russia. Although these taxa are very common, the taxonomic confusion surrounding this complex is reflected in ambiguity of the various taxonomic treatments currently used. Patterns of intraspecific variations of cone morphology and recognition of taxa within the P. jezoensis complex were investigated from 175 individuals. Morphological variation of cone characters was determined by the univariate analysis to be insignificant in separating most previously recognized infraspecific taxa in Korea, China, Russia, and Japan. Our statistical analysis showed that cones from northern populations were larger and wider than those from southern populations. Individuals from South Korea were predominantly smaller even than those from Honshu of Japan which were previously recognized as var. hondoensis. All measured characters appeared to show some clinal variation with changes in latitude, and a distinctive trend was evident. Consequently var. hondoensis, var. koreana, and var. microsperma cannot retain their infraspecific state within the P. jezoensis complex.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.62.1-62.1
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• 2017

In space weather forecast, it is important to determine three-dimensional properties of CMEs. Using 29 limb CMEs, we examine which cone type is close to a CME three-dimensional structure. We find that most CMEs have near full ice-cream cone structure which is a symmetrical circular cone combined with a hemisphere. We develop a full ice-cream cone model based on a new methodology that the full ice-cream cone consists of many flat cones with different heights and angular widths. By applying this model to 12 SOHO/LASCO halo CMEs, we find that 3D parameters from our method are similar to those from other stereoscopic methods (i.e., a triangulation method and a Graduated Cylindrical Shell model). In addition, we derive CME mean density (${\bar{\rho}_{CME}}={\frac{M_{total}}{V_{cone}}}$) based on the full ice-cream cone structure. For several limb events, we determine CME mass by applying the Solarsoft procedure (e.g., cme_mass.pro) to SOHO/LASCO C3 images. CME volumes are estimated from the full ice-cream cone structure. For the first time, we derive average CME densities as a function of CME height for several CMEs, which are well fitted to power-law functions. We will compare densities (front and average) of geoeffective CMEs and their corresponding ICME ones.