• 대한치과교정학회지
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• 제23권2호
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• pp.275-282
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• 1993

When mandibular prognathic patients are operated orthognathic surgery which reduce the oral cavity volume, tongue volume should be harmonized with oral cavity volume to be changed because prevent the relapse of malocclusion. To decide the need for tongue resection, the author measured the tongue volume and oral cavity volume with stone model which were taken by impression method and study the difference between the ratio of tongue and oral cavity volume in mandibular prognathic group and normal group. The samples were consisted of four groups, the 40 subjects of the control group, 40 subjects of the experimental group. Each group was subdivided into male and female group respectively. The results were as follows : 1. The tongue volume and oral cavity volume measurements are $20.7cm^3,\;32.7cm^3$ in the control group respectively, and $24.9cm^3,\;42.9cm^3$ in the experimental group respectively. 2. There is no difference in the ratio of the tongue volume to oral cavity volume in control group and experimental group. 3. Correlation coefficients between the tongue volume and oral cavity volume are 0.11, 0.29 in experimental group and control group respectively, and 0.43 in gross total group. 4. The tongue volume of male is larger than female(p<0.05).

• Radiation Oncology Journal
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• 제29권4호
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• pp.277-282
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• 2011

Purpose: This study was performed to evaluate the change in the lumpectomy cavity volumes before and after whole breast radiation therapy (WBRT) and to identify factors associated with the change of volume. Materials and Methods: From September 2009 to April 2010, the computed tomography (CT) simulation data from 70 patients obtained before and after WBRT was evaluated. The lumpectomy cavity volumes were contoured based on surgical clips, seroma, and postoperative changes. Significant differences in the data from pre-WBRT CT and post-WBRT CT were assessed. Multiple variables were examined for correlation with volume reduction in the lumpectomy cavity. Results: The mean and median volume reduction in the lumpectomy cavity after WBRT were 17.6 $cm^3$ and 16.1 $cm^3$, respectively with the statistical significance (p < 0.001). The volume reduction in the lumpectomy cavity was inversely correlated with time from surgery to radiation therapy (R = 0.390). The presence of seroma was significantly associated with a volumetric change in the lumpectomy cavity after WBRT (p = 0.011). Conclusion: The volume of lumpectomy cavity reduced significantly after WBRT. As the time from surgery to the start ot WBRT increased, the volume reduction in the lumpectomy cavity during WBRT decreased. A strong correlation was observed between the presence of seroma and the reduced volume. To ensure appropriate coverage and to limit normal tissue exposure during boost irradiation in patients who has seroma at the time of starting WBRT, repeating CT simulation at boost planning is suggested.

• 한국지반신소재학회논문집
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• 제18권3호
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• pp.79-88
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• 2019

본 연구에서는 도로노면 하부 지반에서 발생한 공동의 확장특성을 평가하기 위하여, 지하수주입 실험을 수행하였다. 즉, 공동체적에 비례한 일정량의 물을 단계별로 주입하고, 주입한 물이 배출됨에 따라 확대되는 공동을 모니터링 함으로써, 공동의 체적변화를 확인하였다. 실험결과, 지하수 주입에 따른 공동의 체적은 증가하다 수렴 또는 감소하는 경향을 나타냈다. 이는 지하수 주입 시, 공동이 확장되는 과정에서 주변의 이완된 지반이 일부 붕괴되거나 세립토가 주변 지반의 간극을 채우기 때문인 것으로 분석되었다. 또한 지하수 주입 단계에 따른 공동의 체적변화와 확장특성을 분석한 결과, 실험대상 공동은 횡방향으로 확장되는 것을 확인할 수 있었다. 그리고 지하수 유동에 따라 이완된 공동 주변지반이 붕괴되고, 붕괴된 토사가 공동하부의 지중으로 유실되는 과정이 반복됨으로써 공동이 확장되는 것으로 평가되었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권4호
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• pp.294-305
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• 2009

Purpose: This retrospective study evaluated the changes in hyoid bone and tongue positions as well as oral cavity volume after mandibular setback by BSSRO. Materials and Methods: 18 Koreans who underwent BSSRO to correct mandibular prognathism were studied. Lateral cephalograms were taken and traced preoperatively (T0), immediately (T1) and approximately 6 months postoperatively (T2). Submentovertex radiograghs were taken and traced before surgery (T0) and about 6 months after surgery (T2). The area and volume of oral cavity, the vertical and horizontal dimensions of the hyoid bone and tongue dorsum were measured. Results: Mandibular setback surgery resulted in a significant reduction of lower oral cavity volume. The hyoid bone displaced posteroinferiorly immediately after surgery, and it tended to return to its original vertical position at 6 month after mandibular setback by BSSRO. The retropalatal space around tongue was maintained and the retrolingual space around tongue was reduced immediately postoperatively. The readaptation of tongue was not evident for that the follow up period was not long enough. No significant statistical correlations between the amounts of mandibular setback and the changes of oral cavity volume were observed. Conclusion: Mandibular setback surgery resulted in a significant reduction of lower oral cavity volume, which was most likely attributable to the posterior movement of the mandible. More subjects and long-term observations should be performed to assess the changes of oropharyngeal configuration following mandibular setback surgery.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.163-170
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• 1999

Although the bulge forming technique is currently employed in commercial superplastic forming processes, the uniaxial tensile test is still the most commonly used method for the evaluation of the superplasticity of materials due to its simplicity in testing. However, the results obtained from the uniaxial tensile test can not be applied in analyzing the characteristics of the real parts formed in multi-axial stress state. In this paper, using the tensile test specimen obtained from the square cup manufactured by superplastic forming, tensile strength and elongation have been investigated according to the strain and cavity volume fraction. From the result of experiment, tensile strength and elongation are decreased according to the strain and cavity in Al-6%Cu-0.4%Zr alloy. On condition of uniaxial stress, cavity volume fraction is increased on linear according to the increasement of thickness strain. However, on condition of biaxial stress there are critical point( E t=1.5-1.6) that the slope, the ratio of cavity volume fraction and strain, have been changed. Therefore, cavity volume fraction is different with respect to stress condition, although the same strain.

• 한국재난정보학회 논문집
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• 제16권2호
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• pp.267-275
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• 2020

연구목적: 본 연구에서는 공동 영역의 변화를 규명하기 위해 GPR 탐사장비, 유량계, 천공기, 공내 촬영장비, 공동 형상화 장비 등을 사용하여 공동 체적에 비례한 일정량의 물을 주입하고, 주입한 물이 빠짐에 따라 확대되는 공동 영역 변화를 정량적으로 평가하였다. 연구방법: 지하수 주입에 의한 공동 체적변화를 살펴보기 위해 실험공 2개소에 대한 주입시간-주입유량-체적증가량을 측정하였다. 연구결과: 주입시간이 증가할수록 체적증가량은 감소하고 있으며 1시간 정도 주입하면 더 이상의 체적증가가 없음을 알 수 있었다. 결론: 주입실험을 통해 체적변화 양상을 분석하여 공동생성의 원인이 주변 지중 매설물에 대한 영향 유무를 판단할 수 있었다. 그리고 지하수 주입 시, 공동이 확장되는 과정에서 주변의 이완된 지반이 일부 붕괴되거나 세립토가 주변 지반의 간극을 채우기 때문이며, 지하수 주입 유량이 증가할수록 체적변화가 증가하는 것으로 미루어, 공동의 확장은 지하수 유동에 큰 영향이 있음을 알 수 있었다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.119-122
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• 1997

In this paper, we represented the variation of heart cavity area in the space domain by 3-d rendering. We arranged the 2-d sequence of ultrasonic image acquired in the time domain as volumetric data, and extracted heart cavity region from 3-d data. For the segmentation of 3-d volume data, we extracted the cavity region using the method of expanding the cavity region that is same statistical property. By shading which is using light and object normal vector, we visualized the volume data on image plane.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3009-3014
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• 2007

The effectiveness of passive control techniques for alleviating the pressure oscillation generated in a supersonic cavity flow was investigated numerically and experimentally, respectively. The control device includes a sub-cavity installed near the leading edge of a rectangular cavity. Time-dependent supersonic cavity flow characteristics with turbulent features were examined by using the three-dimensional, mass-averaged Navier-Stokes computation based on a finite volume scheme and large eddy simulation. The results show that the pressure oscillation near the trailing edge dominates overall time-dependent cavity pressure variations. Such an oscillation can be attenuated more significantly in the presence of the sub-cavity compared with the cavity without sub-cavity, and a larger sub-cavity leads to better control performance.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 추계학술발표회논문집(1)
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• pp.309-314
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• 1996

Feasibility study has been accomplished to evaluate the effectiveness of the in-vessel core debris cooling through lower cavity flooding using two dimensional finite difference scheme. The volume of cerium pool and decay power rate generated in corium pool were evaluated as important parameters to the temperature distribution on the reactor vessel lower head through previous works. In this study, the corium volume based on the System 80＋ core structure and time dependent decay power rate are considered for feasibility evaluation. In addition, preliminary plans for the in-vessel core debris cooling through lower cavity flooding as severe accident management strategy, i.e. flooding timing, method and capacity, are suggested based on the result of the numerical study, international tendency related to in-vessel core debris cooling through lower cavity flooding.

• Journal of Magnetics
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• 제18권3호
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• pp.321-325
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• 2013

The problem of mixed convection in a differentially heated lid-driven square cavity filled with Cu-water nanofluid under effect of a magnetic field is investigated numerically. The left and right walls of the cavity are kept at temperatures of $T_h$ and $T_c$ respectively while the horizontal walls are adiabatic. The top wall of the cavity moves in own plane from left to right. The effects of some pertinent parameters such as Richardson number (ranging from 0.1 to 10), the volume fraction of the nanoparticles (ranging 0 to 0.1) and the Hartmann number (ranging from 0 to 60) on the fluid flow and temperature fields and the rate of heat transfer in the cavity are investigated. It must be noted that in all calculations the Prandtl number of water as the pure fluid is kept at 6.8, while the Grashof number is considered fixed at 104. The obtained results show that the rate of heat transfer increases with an increase of the Reynolds number, while but it decreases with increase in the Hartmann number. Moreover it is found that based the Richardson and Hartmann numbers by increase in volume fraction of the nanoparticles the rate of heat transfer can be enhanced or deteriorated compared to the based fluid.