• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.44 no.4
• /
• pp.220-226
• /
• 2021

In supply chain, there are a variety of different uncertainties including demand, service time, lead time, and so forth. The uncertainty of demand has been commonly studied by researchers or practitioners in the field of supply chain. However, the uncertainty of upstream supply chain has also increased. A problem of uncertainty in the upstream supply chain is the fluctuation of the lead time. The stochastic lead time sometimes causes to happen so called the order crossover which is not the same sequences of the order placed and the order arrived. When the order crossover happens, ordinary inventory policies have difficult to find the optimal inventory solutions. In this research, we investigate the lead time distribution in case of the order crossover and explore the resolutions of the inventory solution with the order crossover.

• Communications for Statistical Applications and Methods
• /
• v.9 no.3
• /
• pp.607-618
• /
• 2002

Crossover design is often used in clinical trials about chronic diseases like hypertension, asthma and arthritis. In this paper, we suggest nonparametric approaches of Friedman-type rank test based on Bernard-van Elteren test and of aligned method keeping the information of blocks based on the AB/BA/AA/BB crossover design. The simulation results are presented to compare experimental error and power of several methods.

• Proceedings of the Korean Statistical Society Conference
• /
• 2002.11a
• /
• pp.79-83
• /
• 2002

A phase III clinical trial of a new drug for neutropenia induced by chemotherapy is presented and consider adding random effects in crossover design which was used in the clinical study. The diagnostics for its heteroscedasticity based on score statistic is derived for detecting homoscedasticity of errors in crossover design. A small simulation study is peformed to investigate the finite sample behaviour of the test statistic which is known to have an asymptotic chi-square distribution under the null hypothesis.

• Communications for Statistical Applications and Methods
• /
• v.10 no.1
• /
• pp.115-123
• /
• 2003

In this paper, we discuss the usefulness of AB/BA/AA/BB crossover design sense of sample size. The result is that the AB/BA/AA/BB crossover design is more economical than AB/BA one if large carryover effect exists and so is it in the comparison with completely randomized design within-subject correlation is large.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.507-512
• /
• 2003

Even if tracks cross each other, a train has to maintain a good current collection. Where catenary cross each other, it is called a crossover. Based on the cause analysis for a breakdown accident of pantograph occurred in the crossover on Ansan-line, a theoretical background and recommendation for the installation rule of a crossover are presented in the paper.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2002.12a
• /
• pp.375-378
• /
• 2002

In this paper we propose parallel GA to optimize mutation rate and crossover rate using server-client model. The performance of GA depend on the good choice of crossover and mutation rates. Although many researcher has been study about the good choice, it is still unsolved problem. proposed GA optimize crossover and mutation rates trough evolving subpopulation. In virtue of the server-client model, these parameters can be evolved rapidly with relatively low-grade

• Proceedings of the KIEE Conference
• /
• 1998.11a
• /
• pp.332-334
• /
• 1998

Maintenance scheduling is one of mid-term scheduling problems of power systems. There have been many methods for this problem, but there is no effective way to treat all the generators simultaneously except evolutionary algorithms. In this paper, we apply GA to the maintenance scheduling problem. And we proposed new crossover operator(BOX type crossover) to improve searching ability of GA. Satisfactory results are obtained by GA with proposed crossover operator.

• Proceedings of the KSME Conference
• /
• 2001.06a
• /
• pp.636-643
• /
• 2001

Interference between the crossover leg of the reactor coolant system (RCS) and the pipe whip restraints (PWR) has brought a degradation issue of the integrity of the Reactor Coolant System in Westinghouse type nuclear power plants (NPPs) of Korea. According to the gap Inspect ion carried out during planned overhaul (Year 2000), interference between the crossover leg and the PWR was found in each RCS loop. This plant has had the high vibration problem on the RC pump 'B'. The reason for the high vibration in the RC pump 'B' had been massively surveyed and it was found that the crossover leg of RCS contacted with the PWR in hot condition. Since the contact between the crossover leg and the PWR changes the dynamic characteristics of the piping system for the RCS, this is considered as one reason for the high vibration. And a possibility of overstress on the crossover leg due to the contact with the PWR should be evaluated. Through performing RCS integrity analyses, subsequent actions were initiated to increase the gap between those parts. As the results of the appropriate separation between two parts, it was reported that there was no unusual noise or vibration during plant heat-up. In this paper, the evaluations for the gap between the crossover leg and the PWR and the structural integrity due to loop binding is described.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.4
• /
• pp.31-43
• /
• 2021

The talk of today's era is innovation and convergence. Convergence can be seen as innovation because convergence is born through innovation and innovation is made through convergence. Crossover and collaboration (collectively referred to as "crossover") which are used as a concept of convergence in popular culture means the combination and integration of different genres or fields, and has recently been used in various fields such as movies and music. The use of crossover helps to break boundaries with other fields and create new works through free and diverse attempts. Thus, in this study, the convergence of popular culture, or crossover, is analyzed in conjunction with the Korean horror genre. Currently, Korean horror movies were popular from the 1990s to the early 2000s, but now only a few are coming out due to a series of poor box office performances. However, according to this study, crossover attempts have already begun in Korean horror films, and traces of crossover have been found in several successful films. In this study, we will further apply a collaboration of characters such as "Avengers" to present a new direction for Korean horror movies.

• Proceedings of the KSME Conference
• /
• 2008.11b
• /
• pp.2227-2230
• /
• 2008

Crossover of nitrogen from cathode to anode is inevitable in typical membranes used in PEM fuel cells. This crossovered nitrogen accumulates in anode recirculation system and excessive buildup of nitrogen in the recirculating anode gas lowers the hydrogen concentration and finally affects the performance of fuel cell stacks. In this study, characterization of nitrogen gas crossover was investigated in PEM fuel cell stacks. The mass spectroscopy (MS) has been applied to measure the amount of the crossovered nitrogen at the exit of anode. Results show that anode and cathode stoichiometric number ($SR_c$) have a big effect of nitrogen crossover.