• Advances in aircraft and spacecraft science
• /
• 제10권5호
• /
• pp.439-455
• /
• 2023

Free surface fluid oscillation in prolate spheroidal tanks has been investigated analytically in this study. This paper aims is to investigate the sloshing frequencies in spheroidal prolate tanks and compare them with conventional cylindrical and spherical containers to select the best tank geometry for use in space launch vehicles in which the volume of fuel is very high. Based on this, the analytical method (Fourier series expansion) and potential fluid theory in the spheroidal coordinate system are used to extract and analyze the governing differential equations of motion. Then, according to different aspect ratios and other parameters such as filling levels, the fluid sloshing frequencies in the spheroidal prolate tank are determined and evaluated based on various parameters. The natural frequencies obtained for a particular tank are compared with other literature and show a good agreement with these results. In addition, spheroidal prolate tank frequencies have been compared with sloshing frequencies in cylindrical and spherical containers in different modes. Results show that when the prolate spheroidal tank is nearly full and in the worst case when the tank is half full and the free fluid surface is the highest, the prolate spheroidal natural frequencies are higher than of spherical and cylindrical tanks. Therefore, the use of spheroidal tanks in heavy space launch vehicles, in addition to the optimal use of placement space, significantly reduces the destructive effects of sloshing.

• 대한치과교정학회:학술대회논문집
• /
• 대한치과교정학회 2001년도 제34회 학술대회
• /
• pp.27.3-28
• /
• 2001

• 대한치과교정학회:학술대회논문집
• /
• 대한치과교정학회 2002년도 제35회 학술대회
• /
• pp.89.2-90
• /
• 2002

• 대한치과교정학회:학술대회논문집
• /
• 대한치과교정학회 1997년도 제30회 학술대회
• /
• pp.46.2-46.2
• /
• 1997

• 대한치과의사협회지
• /
• 제25권7호통권218호
• /
• pp.651-656
• /
• 1987

• 기술사
• /
• 제23권5호
• /
• pp.6-15
• /
• 1990

• 대한치과교정학회:학술대회논문집
• /
• 대한치과교정학회 1998년도 제31회 학술대회
• /
• pp.90.1-90.1
• /
• 1998

• 대한치과의사협회지
• /
• 제37권4호통권359호
• /
• pp.277-278
• /
• 1999

• 한국항공운항학회지
• /
• 제16권3호
• /
• pp.15-20
• /
• 2008

At the choice of aviation company, safety appears as biggest variable than expenses, speed and comfort so these are concerned not only aviation companies but also countries and customers. Until now, ICAO has been making effort to reduce the flight accident through the safety advice of aviation part, establishment of standard, education, training and develop of navigation aids. Especially in 2008, they emphasize that the flight accident is reduced through researches and applications about SMS as safety regulation. Important primary factor to give influence about promotion of SMS is practice of organization and for this, to investigate recognition about safety management and culture of members. At point of this, this research analyze the recognition degree about how to manage safety and SMS for pilots an mechanics of Korea.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2002년도 추계학술대회논문집
• /
• pp.762-766
• /
• 2002

This paper describes the emotion recognition algorithm using HMM(Hidden Markov Model) method. The relation between the mechanic system and the human has just been unilateral so far. This is the why people don't want to get familiar with multi-service robots of today. If the function of the emotion recognition is granted to the robot system, the concept of the mechanic part will be changed a lot. Pitch and Energy extracted from the human speech are good and important factors to classify the each emotion (neutral, happy, sad and angry etc.), which are called prosodic features. HMM is the powerful and effective theory among several methods to construct the statistical model with characteristic vector which is made up with the mixture of prosodic features