• Design & Manufacturing
• /
• v.2 no.1
• /
• pp.7-10
• /
• 2008

Restriking method is to add to process in order to get the correct size and high precision accuracy of product which is formed in pre-process. This method is widely used at bending work and drawing work. Restriking die is particularly design and used as restriking process is performed. Therefore, production cost is increasing as one process or a two process are added. In this paper, punches and die block of square shell drawing die which could be performed drawing work and restriking process by using only one die are designed in order to solve these factors. The structure of sectional die which can integrate drawing die and restriking die was developed.

• Korean Journal of Computational Design and Engineering
• /
• v.13 no.1
• /
• pp.36-44
• /
• 2008

This paper proposes a modeling and simulation process of a panel production line (PPL) in a shipyard. The panel production line is an assembly process to produce a main panel of a flat block and a curved block. In this paper, its activity analysis is carried out using expression of IDEF0, and its process is qualitatively and quantitatively analyzed and modeled by Petri Nets. A commercial discrete event simulation tool, $QUEST^{TM}$, is used for virtual PPL and simulation. The modeling results by Petri Net are mapped to elements of the simulation tool. Finally, an integrated simulation environment of PPL is implemented in order to efficiently utilize the virtual PPL model. With the help of IDEF0 and Petri Nets, we could systematically analyze and describe the PPL process that are characterized as being concurrent, asynchronous, distributed, parallel, nondeterministic, and/or stochastic. Also, the dynamic and concurrent activities of a PPL system were able to be simulated. A timing concept can be included into the Petri nets model to evaluate performance and dependability issues of the system.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.13 no.1
• /
• pp.858-876
• /
• 2021

Although widely used, the design of the bulbous bow for ships has been difficult due to the complex interference between the wave system generated by the bulb and the wave system of the ship hull. Until now, a bulbous bow has been often designed using Kracht charts, which were established based on model test data, but these charts apply only to ships with a block coefficient C_B = 0.56-0.82, Froude number Fn = 0.20-0.40, and the obtained bulb sizes are only close to optimal. This paper presents a new method for the optimal design of bulbous bow, starting from the design of an initial bulb using Kracht charts for ships with any block coefficient or Froude number, then resizing this initial bulb to define the optimal bulb sizes based on a multi-objective function of the required power reduction, and a combined solution of Computation Fluid Dynamics (CFD) analysis and surrogate models. This study was applied to a fishing vessel FAO 75, which has been model tested and used to design steel fishing vessels in Vietnam recently. The obtained quantitative results showed the same trend as the theory and practice, with a reduction of the ship's required power by about 14%.

• Korean Institute of Interior Design Journal
• /
• no.40
• /
• pp.94-101
• /
• 2003

This study is mentioning about basic information and guide related block types, through a comparison and an analysis of floor types which is shown as function in block types and public interior spaces. For the range of this survey, it is defind in the beginning of 1970' s to the end of 1990' s which was rapidly developed in hotel industry and also is chosen by 12 places in the first class hotels. On the purpose of this study is written by designing the basic information of architectures, new hotels which are built and managed in urban, refer to the survey and analysis of the characteristic in hotel. The following is conclusion by based on pre-survey of the analysis of a plan and a site in these hotels. First, as a result of analysis in block type, there are equally distributed in three types (in-type, combination type, close-type), except a atrium type exception, in 12 hotels(100%). Second, as a result of analysis of function type in public interior space, Con-course type is consist of 7(58%), Hall type is 5(42%) in the type of room in public interior space, in 12 hotels(100%). Third, the type in lobby on space plan are equally shown by the type of lobby in center(4PL.), of lounge in center(4PL.), and a compromising type(4PL.).

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.4C
• /
• pp.356-364
• /
• 2003

Presently, etwork is being in the existence as an influence can not be neglected. This rapid progress of network has gone with development of mobile network and information communication. But the development of network can generate serous social problems. So, it is highly required to control security of network. These problems related security will be developed and keep up to confront with anti-security part such as hacking, cracking. There's no way to preserve security from hacker or cracker without delvelopping new cryptographic algorithm or keeping the state of anti-cryptanalysis in a prescribed time by means of extendig key-length. Worldwidely, many researchers for network security are trying to handle these problems. In this paper, we proposed a new block cryptosystem. The Block cipher-Secure Electronic Xenogenesis Algorithm(B-SEXA) which is capable to cipher regardless of key distribution or key-length for these definite problem is proposed and designed in hardware. B-SEXA increase secret level from using a MDP and MLP in maximum is proposed to prevent cryptograpy analysis. The designed B-SEXA in this paper performed synthesization and simulation using Synopsys Vwe. 1999.10 and VHDL.

• East Asian mathematical journal
• /
• v.37 no.1
• /
• pp.1-7
• /
• 2021

In modern block ciphers, S-box plays a very important role in the secrets of symmetric encryption algorithms. Many popular block ciphers have adopted various S-Boxes to design better S-Boxes. Among the researches, Jin et al. proposed a simple scheme to create a new S-box from Rijndael S-box. Only one of the new S-boxes for 29 is a bijection with a better algebraic representation than the original. Therefore, they asked a few questions. In this paper, we answer the following question : When the resulting S-box is bijection?

• Communications for Statistical Applications and Methods
• /
• v.4 no.3
• /
• pp.707-714
• /
• 1997

The littice designs have prove efficient but they are not alwasy available. This article proposes an alternative, an almost lattice design, of the triple lattice design (v=36, k=6, r=4) which is not available. Here, we compare the almost lattice design to the .alpha.-design (v=36, k=6, r=4) which is another alternative of the triple lattice design (v=36, k=6, r=4). Consequently, we show the almost lattice design is a more efficient alternative than the $\alpha$-design through A-, D-, and E-optimality.

• Proceedings of the KOSOMBE Conference
• /
• v.1991 no.11
• /
• pp.44-47
• /
• 1991

There exists a transform trellis code that is optimal for stationary Gaussian sources and the squared-error distortion measure at all rates. In this paper, we train an asymptotically optimal version of such a code to obtain one which is matched better to the statistics of real world data. The training algorithm uses the M-algorithm to search the trellis codebook and the LBG-algorithm to update the trellis codebook. To adapt the codebook for the varying input data. we use two gain-adaptive methods. The gain-adaptive scheme 1, which normalizes input block data by its gain factor, is applied to images at rate 0.5 bits/pixel. When each block is encoded at the same rate, the nonstationarity among the block variances leads to a variation in the resulting distortion from one block to another. To alleviate the non-uniformity among the encoded image, we design four clusters from the block power, in which each cluster has its own trellis codebook and different rates. The rate of each cluster is assigned through requiring a constant distortion per-letter. This gain-adaptive scheme 2 produces good visual and measurable quality at low rates.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.3 no.2
• /
• pp.64-69
• /
• 2010

This paper designs the ABC(Advanced Block Cipher) algorithm which is a 64byte block encryption algorithm, improves the performance of encryption process time, and makes an key exchange using EC-DH. The ABC algorithm reduces basic memory occupation rates using the original data position exchange method which is a data swap key without S-Box, IP-Box and etc. Also, it prepares the exposure of symmetric key using the unfixed encryption(decryption) key excepting the fixed encryption(decryption) key. Therefore, the proposed ABC algorithm in this paper is a proper encryption algorithm in lower memory environment and mobile banking.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.10a
• /
• pp.337-344
• /
• 2001

The application of mechanically stabilized earth wall(MSEW) with segmental front panel has been increasing in highway construction due to its cost-effectiveness. However, some failures during construction have been reported and many field engineers are reluctant to select this method for important structure. One of the main reasons may be that there is no moderate specification for design and construction of MSEW yet. This paper discussed the main results of analysis on a case of block-type segmental retaining wall in highway construction. Based on the results, some recommendations on design and construction method of MSEW are presented.