• 천문학회보
• /
• 제36권2호
• /
• pp.53.2-53.2
• /
• 2011

We combine the physics of the ellipsoidal collapse model with the excursion set theory to study the shapes of dark matter halos. In particular, we develop an analytic approximation to the nonlinear evolution that is more accurate than the Zeldovich approximation; we introduce a planar representation of halo axis ratios, which allows a concise and intuitive description of the dynamics of collapsing regions and allows one to relate the final shape of a halo to its initial shape; we provide simple physical explanations for some empirical fitting formulae obtained from numerical studies. Comparison with simulations is challenging, as there is no agreement about how to define a non-spherical gravitationally bound object. Nevertheless, we find that our model matches the conditional minor-to-intermediate axis ratio distribution rather well, although it disagrees with the numerical results in reproducing the minor-to-major axis ratio distribution. In particular, the mass dependence of the minor-to-major axis distribution appears to be the opposite to what is found in many previous numerical studies, where low-mass halos are preferentially more spherical than high-mass halos. In our model, the high-mass halos are predicted to be more spherical, consistent with results based on a more recent and elaborate halo finding algorithm, and with observations of the mass dependence of the shapes of early-type galaxies. We suggest that some of the disagreement with some previous numerical studies may be alleviated if we consider only isolated halos.

• Steel and Composite Structures
• /
• 제6권4호
• /
• pp.335-351
• /
• 2006

The present paper hopes to elucidate the problem of determining if a given I-shaped cross-section is properly proportioned to accommodate sufficient plastic hinge rotation capacity to facilitate the redistribution of moments in a structural system as needed to accommodate the formation of a collapse mechanism. It might be tempting to believe that application of the limiting flange plate slenderness value for the case of major axis flexure are applicable in this case; since the pervasive belief is that this approach ought to be conservative. However, the present research study indicates that this is not the case and thus more sophisticated analysis techniques are required to better understand this case.

• 대한기계학회논문집
• /
• 제16권6호
• /
• pp.1156-1162
• /
• 1992

본 연구에서는 종횡비가 다른 3가지의 날카로운 모서리를 가진 타원 슬롯노즐 (AR=1,2,4)을 풍동 수축부 끝에 장착하여 타원제트의 유동특성 및 축교차현상을 3-D LDV 시스템을 이용하여 조사하였다.

• Applied Biological Chemistry
• /
• 제27권2호
• /
• pp.129-134
• /
• 1984

콩나물을 온도별로 길러 생장과정별 단백질조성을 7.5% polyacryl amide gel 전기영동법으로 조사하고 조제표품단백질의 그것으로 동정하였다. 원료대두(大豆)에서는 주(主) band 5개(a,b,c,d 및 p)와 미소 band 10개가 나타났고 4일자자엽(日字子葉)에서는 8개의 주(主) band와 (o band포함)와 11개 미소 band로 최고 band수(數)를 보였다. 배축(胚軸)에서는 자엽(子葉)에서 발견(發見)되는 band들이 모두 나타났으나 분리(分離)가 선명치 못하였다. 생육이 경과함에 따라 자엽(子葉)에서는 a band가 먼저, b,c,d band가 다음으로 감소해 갔으며 미소 band o+p는 6일(日)까지 증가하다 그후 감소하였다. 배축(胚軸)에서는 모든 band가 계속 증가하였는데 미소 band와 b+c+d가 증가속도가 컸다. a band는 7S, b+c+d는 11S, o+p는 2S globulin으로 동정되었다. 생육온도가 높아짐에 따라 자엽(子葉)에서의 감소와 배축(胚軸)에서의 증가속도가 빨라졌으며 7S보다 11S가 촉진되었다.

• 한국측량학회지
• /
• 제8권1호
• /
• pp.23-30
• /
• 1990

본 연구는 조합망 조정에 있어서 승여관측수가 정도에 미치는 영향을 파악하기 위하여 승여관측수를 변화시켜서 망을 조정한 것이다. 또한 수평위치 결정에 있어서 어떤 방법이 가장 효용성이 있는지를 제시하기 위하여 승여관측수에 따른 정밀도를 분석하였다. 본 연구에서 실시한 조합망의 조정에 있어서 평균제곱근 오차는 삼변측량에 비하여 장축에서 약 78∼82%, 단축에서 약 48∼60%, 삼각측량에 비하여 장축에서 약 84∼87%, 단축에서 약 29∼45% 감소되었고, 승여관측수와 정밀도와의 사이에는 Y=464.71429X＋13517.57143의 함수관계가 성립한다. 그러나 승여관측수의 증가가 정밀도를 향상시키므로 최적의 승여관측수의 결정은 경제적인 측면에서 매우 중요한 과제이므로 앞으로의 연구과제라 생각된다.

• Journal of Astronomy and Space Sciences
• /
• 제17권2호
• /
• pp.125-132
• /
• 2000

Long-slit spectra, covering the wavelength range 4050~5150$\AA$, have been used to investigate the radial behavior of absorption line features (G4300, Fe4383, Ca4455, Fe4531, Fe4668, and H$\beta$) along the major and minor axes of the bulge of M104. The heliocentric recession velocity of M104 has been derived as 1260$\pm$190${kms}^{-1}$. The strength of a number of metal absorption lines is decreasing with increasing radius, and the minor axis shows much steeper radial line gradients than the major axis. Line index of H$\beta$ has an opposite trend to other metal lines, i.e., increasing outward. The results in this paper imply that the properties of absorption line index distribution in M104 bulge have in many aspects similar trends to those of elliptical galaxies.

• 대한기계학회논문집
• /
• 제15권6호
• /
• pp.2160-2170
• /
• 1991

본 연구에서는 날카로운 모서리를 가진 타원제트(AR=2)의 근접 영역에서 제트 의 난류구조 및 축교차현상을 3-D LDV 시스템을 이용하여 조사하였다.

• Tribology and Lubricants
• /
• 제14권4호
• /
• pp.58-63
• /
• 1998

This paper presents a study of the elastohydrodynamic lubrication of elliptical contacts where lubricant entrainment coincides with the major axis of the Hertzian contact ellipse. A finite difference method and the Newton-Raphson method are applied to analyze the problem. Film contours and pressure distributions are compared with the results for lubricant entrainment coincides with the minor axis. Variations of the minimum and central film thicknesses with the radius ratio are also examined. The results showed that the present numerical scheme can be used generally in the analysis of the EHL of elliptical contacts where the lubricant entraining vector did not coincide with either of the principal axis of the conjunction.

• Archives of Plastic Surgery
• /
• 제43권6호
• /
• pp.538-543
• /
• 2016

Background Cutaneous squamous cell carcinoma (SCC), which occurs in keratinocytes of the epidermis and is the second most common skin cancer, has a more invasive growth pattern and higher potential to metastasize than basal cell carcinoma. Total excision of the primary tumor is the treatment of choice. For clear excision of the tumor, invasion depth is one of the most important factors. This study was conducted to clarify the relationship between the size and the invasion depth of cutaneous SCC. Methods Twenty-six cases were collected for this prospective study. Frozen biopsies were examined after complete resection of the tumor, followed by histological confirmation by pathological examination. The major and minor axis lengths of the tumor, the invasion depth, and the level of invasion were measured. Recurrence or metastasis was recorded through regular follow-up. Results The Pearson correlation coefficient was used for statistical analysis. Significant results were observed for the relationship between the major and minor axis lengths and the invasion depth of the tumor (0.747, 0.773). No cases of recurrence or metastasis were observed. Conclusions In head and neck cutaneous SCC, the invasion depth of the tumor is closely related to the major and minor axis lengths of the tumor. Therefore, the invasion depth of the tumor can be estimated by measuring the size of the tumor, and a standard vertical safety margin for head and neck cutaneous SCC can be established, which could be helpful in the development of a preoperative reconstruction plan.

• 한국안전학회지
• /
• 제21권1호
• /
• pp.96-104
• /
• 2006

This study is to find out how the sawdust-mixed RC beam with holes acts compared to two case of normal one with sawdust without hole, without sawdust. variables are ED3H1, ED3H2, ED3H1UB, ED3H2L, ED5H1, ED5H1UB, ED5H2, ED5H2L, Normal with sawdust PLA without sawdust. All sand, aggregate, cement are in accordance with KS. mixing design is also in accordance with KS and done at D remicon company in order to decrease any error in mixing manually. ED3H1 showed 7tone of maximum load capacity having only minor tensile deformation around hole, compared to the center of the beam. ED5H2L showed almost same shape of tensile strain between hole area and center of two beam length, while having 9.5 tone load capacity, incase of two holes being in the longitudinal axis. But ED5H2 in case of two holes being in same forcing direction showed 8.4tone of load capacity while having minor tensile chape around hole and normal tensile shape in the center of beam length. Two diameter 3cm hole in longitudinal axis give more effective behavior than the other case, practically. Capacity decrease between 5cm and 3cm in eccentric position form the longitudinal axis is less than percents. There is minor capacity difference between hole diameter 3cm hole, but 13tone difference of load capacity between hole diameter 5cm.