• Imaging Science in Dentistry
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• v.44 no.2
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• pp.165-169
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• 2014

An osteolytic lesion with a small central area of mineralization and sclerotic borders was discovered incidentally in the clivus on the cone-beam computed tomography (CBCT) of a 27-year-old male patient. This benign appearance indicated a primary differential diagnosis of non-aggressive lesions such as fibro-osseous lesions and arrested pneumatization. Further, on magnetic resonance imaging (MRI), the lesion showed a homogenously low T1 signal intensity with mild internal enhancement after post-gadolinium and a heterogeneous T2 signal intensity. These signal characteristics might be attributed to the fibrous tissues, chondroid matrix, calcific material, or cystic component of the lesion; thus, chondroblastoma and chondromyxoid fibroma were added to the differential diagnosis. Although this report was limited by the lack of final diagnosis and the patient lost to follow-up, the incidental skull base finding would be important for interpreting the entire volume of CBCT by a qualified oral and maxillofacial radiologist.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.02a
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• pp.59-70
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• 2000

본 연구에서는 콘관입속도가 콘관입시험 결과에 미치는 영향을 연구하기 위하여 LSU/CALCHAS(Louisiana State University Calibration Chamber System)를 이용한 미니 Piezocone의 관입시험이 수행되었으며 그 결과를 비교 분석하였다. 10회의 미니 Piezocone 관입시험이 Ko 조건에서 수행되었으며 33% kaolin, 67% sand mixture가 시료로 사용되었고, 콘관입속도 0.3, 0.6cm/sec, U1(filter element at the cone tip), U2(filter element above the cone base), OCR=1, 10 의 조건이 다양하게 적용되었다. 시험결과 Cone Resistance, Excess Pore Water Pressure, Sleeve Friction 은 U1, U2 두 종류의 콘에 대해서 모두 관입속도가 커짐에 따라 증가하였으나 OCR의 증가에 따라서는 감소하였으며 U1의 Excess Pore Water Pressure가 U2 경우보다 크게 측정되었다.

• Journal for History of Mathematics
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• v.26 no.5_6
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• pp.371-388
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• 2013

In ${\ll}$The Method${\gg}$, Archimedes presented the famous heuristic technique for calculating areas, volumes and centers of gravity of various plane and solid figures, utilizing the law of the lever. In that treatise, Archimedes used the fact that the center of gravity of a cone lies one-quarter of the way from the center of the base to the vertex, but the proof of this is not extant in his works. This study analyzes the propositions and their relations of ${\ll}$The Method${\gg}$ focusing on the procedural characteristics of the 'method' of Archimedes. According to the result of that analysis, this study discusses the likely approach which was taken for Archimedes to find out the center of gravity of a cone.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.206-212
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• 2009

Chemical behaviors of each surface material for interior facilities affect to fire initiation and growth in general fire situation. These chemical behaviors were characterized by thermal properties (Heat release rate, Pyrolysis rate, specific heat, etc) which could be derived from experimental test. Especially, Heat release rate which indicates aspect of fire size is one of the most important property to asses fire hazard and protection needs. The cone calorimeter test (ISO 5660) has recently assumed to a dominant role in bench scale fire testing to obtain the Heat release rate of materials. This value could be calculated by the 'Oxygen Consumption Method' under various producing irradiances to each surface of materials. In this study, Process of the cone calorimeter test was simulated by Pyrolysis model of FDS (Fire Dynamics Simulator by NIST) base on the ISO 5660 international standard. Then, we could estimate the simulation method of FDS in case of single materials through the comparative study with test results.

• Imaging Science in Dentistry
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• v.46 no.1
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• pp.47-51
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• 2016

Herein, we report and discuss the detection of fossa navicularis magna, a close radiographic anatomic variant of canalis basilaris medianus of the basiocciput, as an incidental finding in cone-beam computed tomography (CBCT) imaging. The CBCT data of the patients in question were referred for the evaluation of implant sites and to rule out pathology in the maxilla and mandible. CBCT analysis showed osseous, notch-like defects on the inferior aspect of the clivus in all four cases. The appearance of fossa navicularis magna varied among the cases. In some, it was completely within the basiocciput and mimicked a small rounded, corticated, lytic defect, whereas it appeared as a notch in others. Fossa navicularis magna is an anatomical variant that occurs on the inferior aspect of the clivus. The pertinent literature on the anatomical variations occurring in this region was reviewed.

• Biomedical Science Letters
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• v.26 no.4
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• pp.360-367
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• 2020

Tuna skin byproduct extract (TSB) was used as a biocompatibility film base material, and its composite film with gellan gum (GG) was prepared. In addition, Pinus thunbergii cone extract (PTCE) was incorporated into the film to provide anti-oxidant and anti-bacteria activities. The tensile strength (TS) of the TSB/GG composite films increased with increasing GG content, whereas elongation at break (E) decreased. TSB/GG film at a ratio of 0.5:0.5 (w/w) showed the most desirable TS and E values. Based on scavenging free radical potentials and disc diffusion method results against growth of bacteria, antioxidant and anti-bacteria activities of films increased with increasing PTCE concentration. Accordingly, this study showed that TSB/GG could be used as a film material while the TSB/GG composite film containing PTCE can be utilized as functional packaging.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.817-832
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• 2021

In this paper, a simple practical method to estimate the drag of Super-Cavitating Underwater Vehicles (SCUV) is proposed that can obtain the drag with only principal dimensions in an initial design stage. SCUV is divided into cavitator, forebody, afterbody, base, and control fin and the drag of each part is estimated. The formulas for the drag coefficient are proposed for the disk and cone type cavitators and wedges used as control fins. The formulas are a function of cavitation number, cone or wedge angle, and Reynolds number. This method can confirm the drag characteristics of SCUV that the drag hump appears according to the coverage of the body by the cavity and the cavitator drag remains only when the entire body is covered by cavity. Applying this method to SCUV of various shapes, it is confirmed that the effects of cavitating and non-cavitating conditions, cavitator and body shape, and speed could be found.

• The Journal of the Petrological Society of Korea
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• v.7 no.1
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• pp.1-14
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• 1998

Dangsanbong volcano, which is located on the coast of the western promontory of Cheju Island, occurs in such a regular pattern on the sequences which represent an excellent example of an eruptive cycle. The volcano comprises a horseshoe-shaped tuff cone and a younger nested cinder cone on the crater floor, which are overlain by a lava cap at the top of the cinder cone, and wide lava plateau in the moat between two cones and in the northern part. The volcanic sequences suggest volcanic processes that start with Surtseyan eruption, progress through Strombolian eruption and end with Hawaiian eruption, and then are followed by rock fall from sea cliff of the tuff cone and by air fall from another crater. It is thought that the eruptive environments of the tuff cone could be mainly emergent because the present cone is located on the coast, and standing body of sea water could play a great role. It is thought that the now emergent part of the tuff cone was costructed subaerially because there is no evidence of marine reworking. The emergent tuff cone is characterized by distinctive steam-explosivity that results primarily from a bulk interaction between rapidly ascending magma and external water. The sea water gets into the vent by flooding accross or through the top or breach of northern tephra cone. Dangsanbong tuff cone was constructed from Surtseyan eruption which went into with tephra finger jetting explosion in the early stage, late interspersed with continuous upruch activities, and from ultra-Surtseyan jetting explosions producting base surges in the last. When the enclosure of the vent by a long-lived tephra barrier would prevent the flooding and thus allow the vent to dry out, the phreatomagmatic activities ceased to transmit into magmatic activity of Strombolian eruption, which constructed a cinder cone on the crater floor of the tuff cone Strombolian eruption ceased when magma in the conduit gradually became depleted in gas. In the Dangsanbong volcano, the last magmatic activity was Hawaiian eruption which went into with foundation and effusion of basalt lava.

• Journal of Biosystems Engineering
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• v.9 no.2
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• pp.8-18
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• 1984

To investigate the most important factors affecting the mobility of power tiller and to find the method which can be used for predicting the mobility of power tiller in soft paddy field, a series of field experiment was performed with two models of power tiller (8ps and 6ps diesel). From the results obtained throughout field experiment, the following conclusions were derived. 1. The wheel sinkage of power tiller during both traveling and field operations, which mainly influence the mobility, could be predicted from both plate ($50{\times}100mm$) sinkage and soil cone index (30-degree cone with 2 and $6cm^2$ base area). 2. Prediction of wheel sinkage from the rectangular plate sinkage was found to be more suitable compared with the cone index. 3. The upper limit of rectangular plate sinkage was found as 15 centimeter for operation of power tiller in muddy field which is equivalent of $1kg/cm^2$ of $2cm^2$ cone index value.

• Earthquakes and Structures
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• v.13 no.6
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• pp.561-572
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• 2017

Seismic base isolation has been accepted as one of the most popular design procedures to protect important structures against earthquakes. However, due to lack of information and experimental data the application of base isolation is quite limited to nuclear power plant (NPP) industry. Moreover, the effects of inelastic behavior of soil beneath base-isolated NPP have raised questions to the effectiveness of isolation device. This study applies the wavelet analysis to investigate the effects of soil-structure interaction (SSI) on the seismic response of a base-isolated NPP structure. To evaluate the SSI effects, the NPP structure is modelled as a lumped mass stick model and combined with a soil model using the concept of cone models. The lead rubber bearing (LRB) base isolator is used to adopt the base isolation system. The shear wave velocity of soil is varied to reflect the real rock site conditions of structure. The comparison between seismic performance of isolated structure and non-isolated structure has drawn. The results show that the wavelet analysis proves to be an efficient tool to evaluate the SSI effects on the seismic response of base-isolated structure and the seismic performance of base-isolated NPP is not sensitive to the effects in this case.