• Bulletin of the Korean Mathematical Society
• /
• v.44 no.4
• /
• pp.709-719
• /
• 2007

In [8], it is shown that the complete multipartite graph $K_{n(2t)}$ having n partite sets of size 2t, where $n{\geq}6\;and\;t{\geq}1$, has a decomposition into gregarious 6-cycles if $n{\equiv}0,1,3$ or 4 (mod 6). Here, a cycle is called gregarious if it has at most one vertex from any particular partite set. In this paper, when $n{\equiv}0$ or 3 (mod 6), another method using difference set is presented. Furthermore, when $n{\equiv}0$ (mod 6), the decomposition obtained in this paper is ${\infty}-circular$, in the sense that it is invariant under the mapping which keeps the partite set which is indexed by ${\infty}$ fixed and permutes the remaining partite sets cyclically.

• Journal of the Korea Safety Management & Science
• /
• v.9 no.6
• /
• pp.181-191
• /
• 2007

The purpose of this paper is to develop an efficient production strategy with changing factors to influence the productivity. The factors would be the number of Multi-Function worker, the method of job dispatching, and lot size. A simulation model has been developed for this study. We used AutoMod simulation and the process activity was animated to follow the flow of process easily. The alternatives have been tested through the simulation model, and the various alternatives is proposed for the efficient production strategy. We hope that the system is applied to similar types of small and medium-sized enterprises to develop an efficient production strategy and to achieve the satisfactory result.

• Journal of the Korea Society for Simulation
• /
• v.7 no.2
• /
• pp.33-43
• /
• 1998

To evaluate the server performance and forecast capacity requirements, we carry out simulation of Multimedia-on-demand(MOD) server. In multimedia service environment, especially for on-demand service, one of the key problems is capacity planning, which requires ensuring that adequate computer resources will be available to meet the future workload demands in a cost-effective manner. In this paper, we design and implement a simulation model for MOD server with failures of components (e.g., processors, disks and networks). By acquisition of utilization and queue length parameters, we can estimate desirable capacity of server components with various arrival rates of customers and failure rates of components. For a given failure probability, we also compute packet delay probability and reliability of the server. It is possible to derive some important design information of the MOD server by using the above parameters.

• 한국초전도학회:학술대회논문집
• /
• 2007.07a
• /
• pp.95-95
• /
• 2007

• 한국초전도학회:학술대회논문집
• /
• 2007.07a
• /
• pp.78-78
• /
• 2007

• 한국초전도학회:학술대회논문집
• /
• 2008.08a
• /
• pp.65-65
• /
• 2008

• 한국초전도학회:학술대회논문집
• /
• v.12
• /
• pp.83-83
• /
• 2002

• 한국초전도학회:학술대회논문집
• /
• v.15
• /
• pp.76-76
• /
• 2005

• Nuclear Engineering and Technology
• /
• v.18 no.3
• /
• pp.200-208
• /
• 1986

The loss of coolant accident based on a double-ended cold leg break is analyzed with the discharge coefficient (Ca) of 0.4. This analysis covers the whole transient period from the start of depressurization to the complete refilling of the core by using RELAP4/MOD6-EM and RELAP4/ MOD6-HOT CHANNEL for the system thermal-hydraulics and the fuel performance during the blowdown phase respectively, and RELAP4/MOD6-FLOOD and TOODEE2 during the reflood phase. A simple analytical method has been developed to account for the lower plenum filling by approximating steam-water countercurrent flows and superheated wall effects at the downcomer during the refill period. Based on the informations. at the time of EOB (end-of-bypass), the refill duration time and the initial reflooding temperature were estimated and compared with the results from the RELAP4/MOD6, resulting in a good agreement. In addition, some parametric studies on the EOB were performed. The form loss coefficient between upper head and upper downcomer was found to be sensitive to the occurrence of the spurious EOB. Appropriate form loss coefficients should be taken into account to avoid the flow oscillations at the downcomer. The analyses with the six and three volume core nodalizations, respectively, show much similar trends in the system thermal-hydraulic performance, but the former case is recommended to obtain good results.

• Journal of the Korea Society of Computer and Information
• /
• v.18 no.4
• /
• pp.123-129
• /
• 2013

The performance and practicality of cryptosystem for encryption, decryption, and primality test are primarily determined by the implementation efficiency of the modular exponentiation of $a^b$ (mod m). To compute $a^b$ (mod m), the standard binary squaring (square-and-multiply) still seems to be the best choice. However, in large b bits, the preprocessed n-ary, ($n{\geq}2$ method could be more efficient than binary squaring method. This paper proposes a square-and-divide and unpreprocessed n-ary square-and-divide modular exponentiation method. Results confirmed that the square-and-divide method is the most efficient of trial number in a case where the value of b is adjacent to $2^k+2^{k-1}$ or to. $2^{k+1}$. It was also proved that for b out of the beforementioned range, the unpreprocessed n-ary square-and-divide method yields higher efficiency of trial number than the general preprocessed n-ary method.