• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2003.10a
• /
• pp.133-144
• /
• 2003

Generally, diaphragms are installed in the box girder to prevent or decrease the distortion of tile cross section. In engineering practice, diaphragms are spaced in 5m intervals without reasonable basis. ANd the usual diaphragm type is solid-plate type. It is considered to be noneconomical design to the almost design engineers. In this paper, the parametric study was performed to present the design proposal about the diaphragm stiffness and spacing only in tire single cell box girder. For that, the distortional warping normal stress, bending normal stress and transverse bending normal stress were analyzed using finite element program 'SMB' for the accurate structural analysis.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.9 no.8
• /
• pp.867-873
• /
• 2014

Since the computation of a multiplicative inverse using MONB includes many squarings and thus calculating inverse is expensive, we, in this paper, propose a low cost inverse algorithm requiring $nb(2^nm-1)+w(2^nm-1)-2$ multiplications and $2^n-1$ squarings to compute an inverse in $GF(2^{2^nm})^*$ using special normal basis over $GF(2^{2^n})$, and give some implementation results using the algorithm and, show that the timing results of our implementation is faster than that of Itoh et al.'s method.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.31 no.5
• /
• pp.57-72
• /
• 1999

Traditional theories of the tensile failure of paper have assumed that uniform strain progresses throughout the sheet until an imperfection within the structure causes a catastrophic break. The resistance to tensile elongation is assumed to be elastic , at first, throughout the structure, followed by an overall plastic yield. However, linear image strain analysis (LISA) has demonstrated that the yield in tensile loading of paper is quite non-uniform throughout the structure, Traditional theories have failed to define the flaws that trigger catastrophic failure. It was assumed that a shive or perhaps a low basis weight area filled that role. Studies of the fracture mechanics of paper have typically utilized a well-defined flaw around which yield and failure could be examined . The flaw was a simple razor cut normal to the direction of tensile loading. Such testing is labeled mode I analysis. The included fla in the paper was always normal to the tensile loading direction, never at another orientation . However, shives or low basis weight zones are likely to be at random angular orientations in the sheet. The effects of angular flaws within the tensile test were examined. The strain energy density theory and experimental work demonstrate the change in crack propagation from mode I to mode IIas the initial flaw angle of crack propagation as a function of the initial flaw angle is predicted and experimentally demonstrated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.05a
• /
• pp.469-472
• /
• 2003

The computational cost of encryption is a barrier to wider application of a variety of data security protocols. Virtually all research on Elliptic Curve Cryptography(ECC) provides evidence to suggest that ECC can provide a family of encryption algorithms that implementation than do current widely used methods. This efficiency is obtained since ECC allows much shorter key lengths for equivalent levels of security. This paper suggests how improvements in execution of ECC algorithms can be obtained by changing the representation of the elements of the finite field of the ECC algorithm. Specifically, this research compares the time complexity of ECC computation eve. a variety of finite fields with elements expressed in the polynomial basis(PB) and normal basis(NB).

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.51 no.6
• /
• pp.290-295
• /
• 2002

The present assignment in installing the number of switches for distribution line was made on the basis of a normal feeder capacity 7,000kVA in KEPCO(Korea Electric Power Corporation), Korea. But the normal capacity is revised to 10000kVA in 1998. Even increasing limit of the operating capacity of the distribution lines enables us to give some benefit for the operation flexibility and investment cost of the distribution system. It is disadvantageous in the viewpoint of supply reliability. In distribution systems, switches are equipped to improve the reliability of distribution systems by minimizing the outage section due to fault and maintenance. Utility generally improves the reliability by minimizing the length of outage section, which is caused by fault and maintenance, through switch equipment on distribution system. In order to cope with the changes such as operation capacity, it is necessary to study whether the present criteria is reasonable or not, also to confirm whether the present criteria of installing switches in line is improved or not. In this study, we proposes the number of switch per feeder on the basis of present operation capacity in distribution system.

• Journal of the Korean Institute of Educational Facilities
• /
• v.16 no.1
• /
• pp.33-41
• /
• 2009

The purpose of this study is to provide a basis for calculation of school operation fees for normal functioning of the school facilities, and facility maintenance and repair cost through their life spans, considering remodeling of the facilities and changes of their functions. This study analyzes maintenance and repair records during the three years from 2003 to 2005 in primary, middle and high schools in Incheon Metropolitan city and also the facility management and operation expenditure of the same schools in the city during the year of 2005, and presents quantified unit cost of each item according to the area, the age of the facilities, and the number of classroom, student, and lessons given. The calculation can be a basis for both BTL school facility managers and the general school facility mangers to budget school facility maintenance cost appropriately and the quantity of energy, water, electricity, and telephone fees calculated here can be a criteria for the managers to check the normal maintenance of their facility.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.13 no.4
• /
• pp.347-356
• /
• 1989

The purpose of this study was to investigate the relationships between personality traits and clothing behavior of the normal and disabled females, and to find out the difference in clothing behavior of the two groups. Questionaires for clothing behavior were chosen from the items which had been used in previous studies, and the items were selected on the basis of Cronbach's Alpha Reliability Coefficient. Clothing behavior was composed of four variables: aesthetics; comfort; modesty; and satisfaction. For measurement of 3 personality traits (emotional stability, sociability, and superiority), a portion of 'Personality Inventory' b) Sangro Lee, Changjin Byeon, and Wuigyo Jin was used. Samples were 286 females in Seoul, of whom 110 were normal high school girls, 86 were norma1 college women, 41 were disabled high school girls, and 49 were disabled college women. The data were analyzed using F-test, F-test, and correlation coefficient. The results of the study were the followings: 1. There were meaningful relationships between personality traits and clothing behavior 1) Stability had negative relations to aesthetics and modesty and positive relation to satisfaction. In the case of the normal, stability had no relation to comfort, but in the case of the disabled, it had positive relation to comfort. 2) The sociability had positive relations to aesthetics and satisfaction. 3) The superiority had negative relation to modesty, it had positive relation to satisfaction. The superiority of the normal had negative relation to comfort, whereas the superiority of the disabled had positive relation to comfort. 2. There was a difference in the clothing aesthetics between the normal and the disabled. 3. In case of the normal, college women regarded comfort less important than high school girls. In case of the disabled, college women regarded comfort more important than high school girls. 4. In upper class, there was no difference on the clothing comfort between the normal and the disabled. But there was difference on comfort between the normal and the disabled in low class.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.16 no.2
• /
• pp.105-111
• /
• 2006

Cryptographic application and coding theory require operations in finite field $GF(2^m)$. In such a field, the area and time complexity of implementation estimate by memory and time delay. Therefore, the effort for constructing an efficient multiplier in finite field have been proceeded. Massey-Omura proposed a multiplier that uses normal bases to represent elements $CH(2^m)$ [11] and Agnew at al. suggested a sequential multiplier that is a modification of Massey-Omura's structure for reducing the path delay. Recently, Rayhani-Masoleh and Hasan and S.Kwon at al. suggested a area efficient multipliers for modifying Agnew's structure respectively[2,3]. In [2] Rayhani-Masoleh and Hasan proposed a modified multiplier that has slightly increased a critical path delay from Agnew at al's structure. But, In [3] S.Kwon at al. proposed a modified multiplier that has no loss of a time efficiency from Agnew's structure. In this paper we will propose a multiplier by modifying Rayhani-Masoleh and Hassan's structure and the area-time complexity of the proposed multiplier is exactly same as that of S.Kwon at al's structure for type-II optimal normal basis.

• Structural Engineering and Mechanics
• /
• v.14 no.6
• /
• pp.679-698
• /
• 2002

In this paper some techniques for the dynamic analysis of non-classically damped linear systems are reviewed and compared. All these methods are based on a transformation of the governing equations using a basis of complex or real vectors. Complex and real vector bases are presented and compared. The complex vector basis is represented by the eigenvectors of the complex eigenproblem obtained considering the non-classical damping matrix of the system. The real vector basis is a set of Ritz vectors derived either as the undamped normal modes of vibration of the system, or by the load dependent vector algorithm (Lanczos vectors). In this latter case the vector basis includes the static correction concept. The rate of convergence of these bases, with reference to a parametric structural system subjected to a fixed spatial distribution of forces, is evaluated. To this aim two error norms are considered, the first based on the spatial distribution of the load and the second on the shear force at the base due to impulsive loading. It is shown that both error norms point out that the rate of convergence is strongly influenced by the spatial distribution of the applied forces.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2008.04a
• /
• pp.216-221
• /
• 2008

Shape design optimization for linear elasticity problem is performed using isogeometric analysis method. In many design optimization problems for real engineering models, initial raw data usually comes from CAD modeler. Then designer should convert this CAD data into finite element mesh data because conventional design optimization tools are generally based on finite element analysis. During this conversion there is some numerical error due to a geometry approximation, which causes accuracy problems in not only response analysis but also design sensitivity analysis. As a remedy of this phenomenon, the isogeometric analysis method is one of the promising approaches of shape design optimization. The main idea of isogeometric analysis is that the basis functions used in analysis is exactly same as ones which represent the geometry, and this geometrically exact model can be used shape sensitivity analysis and design optimization as well. In shape design sensitivity point of view, precise shape sensitivity is very essential for gradient-based optimization. In conventional finite element based optimization, higher order information such as normal vector and curvature term is inaccurate or even missing due to the use of linear interpolation functions. On the other hands, B-spline basis functions have sufficient continuity and their derivatives are smooth enough. Therefore normal vector and curvature terms can be exactly evaluated, which eventually yields precise optimal shapes. In this article, isogeometric analysis method is utilized for the shape design optimization. By virtue of B-spline basis function, an exact geometry can be handled without finite element meshes. Moreover, initial CAD data are used throughout the optimization process, including response analysis, shape sensitivity analysis, design parameterization and shape optimization, without subsequent communication with CAD description.