• 한국주조공학회지
• /
• 제13권6호
• /
• pp.540-546
• /
• 1993

The effects of fluid flow on the purification of aluminum were studied. As the revolution rate(N) increased, the size of columnar grain decreased gradually. The concentration of solidified crystal was decreased with increasing distance from chill and revolution rate(N). Distribution boundary layer thickness(${\delta}$) was calculated from the solute distribution obtained in solid experimentally and by use of BPS equation. The value of ${\delta}$ changed from about $60{\mu}m$ at N value of 27rpm to about $15{\mu}m$ at N value of 1000rpm. From this result, high purification was obtained by decreasing the diffusion boundary layer under forced convection.

• Journal of Information Technology Applications and Management
• /
• 제24권1호
• /
• pp.157-167
• /
• 2017

This paper proposes a simple sound source localization (SSL) method based on signal energies comparison and partial cross correlation for TDOA computation. Many sound source localization methods include multiple TDOA computations in order to eliminate front-back confusion. Multiple TDOA computations however increase the methods' computation times which need to be as minimal as possible for real-time applications. Our aim in this paper is to achieve the same results of localization using fewer computations. Using three microphones, we first compare signal energies to predict which quadrant the sound source is in, and then we use partial cross correlation to estimate the TDOA value before computing the azimuth value. Also, we apply a threshold value to reinforce our prediction method. Our experimental results show that the proposed method has less computation time; spending approximately 30% less time than previous three microphone methods.

• 태양에너지
• /
• 제8권1호
• /
• pp.82-94
• /
• 1988

The hydrodynamic stability equations for natural convection flows adjacent to a vertical isothermal surface in cold or warm water (Boussinesq or non-Boussinesq situation for density relation), constitute a two-point-boundary-value (eigenvalue) problem, which was solved numerically using the simple shooting and the orthogonal collocation method. This is the first instance in which these stability equations have been solved using a computer code COLSYS, that is based on the orthogonal collocation method, designed to solve accurately two-point-boundary-value problem. Use of the orthogonal collocation method significantly reduces the error propagation which occurs in solving the initial value problem and avoids the inaccuracy of superposition of asymptotic solutions using the conventional technique of simple shooting.

• 한국식품영양과학회지
• /
• 제28권4호
• /
• pp.865.1-870
• /
• 1999

This study was carried out to use the shrink discharged during process of smoke meat products. Qualities of sausage were grasped, and investigated storage properties during five weeks. The gel strength of pork sausage were 1,461~1,847g.cm, this of chicken sausage were 865~1,733g.cm. The cooking yield of sausage were 81~ 85% in general, contents of salt were 2.5~2.9%. The L value(lightness) of pork sausage were 44.8~47.2, those of chicken sausage were 43.1~48.0, and the L value of the interior was higher than the surface. The remainder contents of nitrite were 3.1~9.4ppm, the sorbic acid contents of all sausage were 0.8g/kg. The amino acid contents of chicken sausage were higher than those of pork sausage. The pH of sausage not changed uniformly during storage. The TBA value and the VBN contents were a slight tendency to increase during storage. The total plate counts of all sausage maintained 104 less than during storage.

• 산업경영시스템학회지
• /
• 제37권4호
• /
• pp.239-244
• /
• 2014

The conventional clustering approaches are mostly based on minimizing total dissimilarity of input and output. However, the clustering approach may not be helpful in some cases of clustering decision making units (DMUs) with production feature converting multiple inputs into multiple outputs because it does not care converting functions. Data envelopment analysis (DEA) has been widely applied for efficiency estimation of such DMUs since it has non-parametric characteristics. We propose a new clustering method to identify groups of DMUs that are similar in terms of their input-output profiles. A real world example is given to explain the use and effectiveness of the proposed method. And we calculate similarity value between its result and the result of a conventional clustering method applied to the example. After the efficiency value was added to input of K-means algorithm, we calculate new similarity value and compare it with the previous one.

• 산업기술연구
• /
• 제20권B호
• /
• pp.213-218
• /
• 2000

The nearest neighbor query is an important operation widely used in multimedia databases for finding the object that is most similar to a given query object. Most of techniques for processing nearest neighbor queries employ multidimensional indexes for effective indexing of objects. However, the performance of previous multidimensional indexes, which use N-dimensional rectangles or spheres for representing the capsule of the object cluster, deteriorates seriously as the number of dimensions gets higher. This paper proposes a new index structure based singular value decomposition resolving this problem and the query processing method using it. We also verify the superiority of our approach through performance evaluation by performing extensive experiments.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
• /
• pp.475-478
• /
• 2005

This study was performed to evaluate about load bearing capacity of continuos IPC Girder Bridge under and after Construction. This is Ichi-1 Bridge that is 2-40m span continuous bridge on a extension road through the Ichun and the Naesa. The result of static loading test to use a 25ton truck after construction, deflection ratio is 0.64 that is $35\%$ and average of response ratio is 0.48$\~$0.89 that is less than theoretical value. The result of dynamic loading test, the number of proper vibrations is 3.06Hz that is like theoretical value 3.61Hz, the modulus of impact is 0.235 that is bigger than specification 0.19. the load bearing capacity is minimum DB-40 that is so big value. In the result, continuos IPC Girder Bridge is safe in short period. we will evaluate long period behavior of continuos IPC Girder Bridge.

• 가족자원경영과 정책
• /
• 제6권1호
• /
• pp.35-51
• /
• 2002

This study is the basic step of including the economical value of household labor into the existing GDP. Therefore this study analyzes statistical data; $\mathbb{\ulcorner}$Economical Active Population Survey$\mathbb{\lrcorner}$, $\mathbb{\ulcorner}$Time Used Survey$\mathbb{\lrcorner}$, $\mathbb{\ulcorner}$Basic Wage Structural Survey$\mathbb{\lrcorner}$, and $\mathbb{\ulcorner}$City Household Survey$\mathbb{\lrcorner}$ for that step and will help people to reconsider the importance of the economical value household work. Economical Active Population Survey classifies housework as economically nonoproductive activity Time Use Survey does not have an clear classification for action. Basic Wage Structural Survey must give subdividable information on wage. City Household Survey should include more details and more data of household durables.

• 한국조리학회지
• /
• 제14권1호
• /
• pp.152-160
• /
• 2008

The purpose of this study was to investigate the sensory characteristics of brown sauce made with different ratios of Jubak. In the brown sauce made from Jubak, the followings showed changes according to the amount of Jubak. The content of crude lipid increased, that of crude protein and moisture decreased, and that of crude ash and reduced sugar increased. Brown sauce made from Jubak contained more reduced sugar than general brown sauce, and the content of reduced sugar increased. pH increased from initial pH 4.32 to 5.42 respectively, and viscosity increased. The "L" value expressing brightness of samples had a tendency to increase with Jubak added. "a" value had a tendency to increase in case of no Jubak added, and "b" value had a tendency to decrease according to the amount of Jubak. In the sensory evaluation, color and flavor decreased and viscosity increased with the amount of Jubak. Overall, it was the highest in 0% Jubak. From the above results, an addition of 25% Jubak to brown sauce is recommended for commercial use.

• Journal of information and communication convergence engineering
• /
• 제5권3호
• /
• pp.259-264
• /
• 2007

According to the development and wide use of broad band internet etc., diverse application technologies using large capacity data such as images have been progressed and in these systems, for accurate acquisition and precise applications of an original signal, the degradation phenomenon generated in the transmission process etc. should be removed. Noises have become known as the main cause of the degradation phenomenon and especially Gaussian noise represents characteristics occurring dependently in image signals and degrades detail information such as edge. In this paper, we removed Gaussian noise using a subdivided nonlinear function according to a threshold value and analyzed the histogram acquired from an edge image to establish a threshold value adaptively, and strengthened detail information of image by using the postprocessing. In simulation results, the proposed method represented excellent performance from comparison of MSE with existing methods.