• Journal of applied mathematics & informatics
• /
• v.26 no.1_2
• /
• pp.191-201
• /
• 2008

In this paper, we consider an insurance risk model governed by a compound Binomial arrival claim process and by a compound Binomial arrival premium process. Some formulas for the probabilities of ruin and the distribution of ruin time are given, we also prove the integral equation of the ultimate ruin probability and obtain the Lundberg inequality by the discrete martingale approach.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.9 no.3
• /
• pp.69-75
• /
• 2010

A hollow flanged spindle is generally used for the assembly of the driving shaft in some vehicles. This part has conventionally been manufactured by both hot forging and machining process, in which case a circular billet is hot-forged into a flanged spindle blank and then its central part is machined for hollow. Therefore, the development of a new forming technology without further machining processes has strongly been in demand. In this study, a new compound forging process of the hollow flanged spindle was proposed through the finite element simulation. By the proposed compound forging process, both extruding of the spindle body part and piercing for the hollow inside it can be performed at the same time. Metal flow patterns, forging defects and forging forces were investigated through the finite element simulation results.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.182-186
• /
• 1996

In this work, a method is described to investigate the progressive and compound process in the coining and piercing operation for given conditions and parameters, using the FEM simulation and model experiment. The effect of the die shape on the compound process is established, and the die shape depends on the position of coining die and the width of the part coined. It is found that Progressive process is better than compound process, since material's filling into the die is not completed and the higher stress acts on the edge of the punch according to width being increased.

• Journal of the Korean Society for Heat Treatment
• /
• v.37 no.2
• /
• pp.49-57
• /
• 2024

We investigated the changes in microstructure and surface roughness of the compound layer of GC250D gray cast iron, commonly used in brake discs, during gas nitriding. The gas atmosphere of the nitriding process was controlled with a hydrogen partial pressure of 49.5%, and the process was conducted at a nitriding temperature of 520℃ with various process times. As the nitriding process time of the GC250D material increased, both the depth of hardening and the thickness of the compound layer increased, with a maximum surface hardness of approximately 1265 HV_0.1 was measured. Additionally, the surface roughness increased with the process time. Phase analysis of the compound layer revealed an increase in the proportion of the γ' phase as the nitriding process time increased. Changes in the formation of the compound layer were observed depending on the orientation of graphite within the material, leading to the formation of wedges. Therefore, the increase in surface roughness appears to be attributed to the uneven compounds, the expansion of the compound layer and wedges formed on the surface during the nitriding process.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.26 no.3
• /
• pp.67-73
• /
• 2003

Manufacturing technologies of compound semiconductor are similar to the process of memory device, but management technology of manufacturing process for compound semiconductor is not enough developed. Semiconductor manufacturing environment also has been emerged as mass customization and open foundry service so integrated manufacturing system is needed. In this study we design the integrated manufacturing system for compound semiconductor fabrication t hat has monitoring of process, reduction of lead-time, obedience of due-dates and so on. This study presents integrated manufacturing system having database system that based on web and data acquisition system. And we will implement them in the actual compound semiconductor fabrication.

• Journal of Korean Institute of Industrial Engineers
• /
• v.31 no.1
• /
• pp.27-35
• /
• 2005

Due to the importance of lead time demand in the design of inventory management systems, researchers and practitioners have paid continuous attention and a few analytic models using the compound distribution approach have been reported. However, since the nature of compound distributions is hardly amenable, the analytic models have been done by non‐recognition of the compound nature of some components to reduce the analytic task. This study concerns some of the important aspects in the analytic models. Through the theoretic examination of the analytic model approach and the comparison with the rigid compound stochastic process approach, this study clarifies the assumptions implicitly made by the analytic models and provides some precautions in using the analytic models. Illustrative examples are also presented.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.4
• /
• pp.296-309
• /
• 2009

Thick-walled cylinder with high pressure have had wide application in the armament industry. In the thick-walled cylinder, fatigue crack is generated at inner radius and developed toward the outer radius. To prevent generation of fatigue crack, the autofrettage process had been used. The compressive residual stress induced by the autofrettage process extends loading pressure and fatigue life of the thick-walled cylinder. In this study, the residual stress of single and compound cylinder by the autofrettage process was evaluated. The analytical compressive residual stress of single cylinder was good agreement with experimental result at inner radius. The analysis on the residual stress of compound cylinder was conducted. The compressive residual stress at inner radius was increased with the overstrain level. And fatigue life of the compound cylinder with initial crack was evaluated. The considered initial crack shape was straight and semi-elliptical. The fatigue life was extended with the overstrain level. The fatigue life of the compound cylinder with semi-elliptical crack was longer than straight crack. The suitable way to extend fatigue life of the compound cylinder was proposed.

• Journal of the Korea Institute of Building Construction
• /
• v.3 no.4
• /
• pp.111-117
• /
• 2003

Recently SAMWOO EMC received order and built interior walls which was used the day process in several high-rise compound buildings. On the way to build, this process was brought about several matter according to the progress and qualify control. So, this study is the improving way of the dry process from experiences on those constructions

• Journal of the Korean Statistical Society
• /
• v.36 no.2
• /
• pp.229-235
• /
• 2007

We consider a ruin model whose surplus process is formed by a compound Poisson process. If the level of surplus reaches V > 0, it is assumed that a certain amount of surplus is invested. In this paper, we apply the optional sampling theorem to the surplus process and obtain the expectation of period T, time from origin to the point where the level of surplus reaches either 0 or V. We also derive the total and average amount of surplus during T by establishing a backward differential equation.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.21 no.2
• /
• pp.209-216
• /
• 1997

A feature is well known as a medium to integrate CAD, CAPP and CAM systems. For a part drawing including both simple geometry and compound geometry, a process plan such as the selection of process, machine tool, cutting tool etc. normally needs simple geometry data and non-geometry data of the feature as the input. However, a extended process plan such as the generation of process sequence, operation sequence, jig & fixture, NC program etc. necessarily needs the compound geometry data as well as the simple geometry data and non-geometry data. In this paper, we propose a feature data model according to the result of analyzing necessary data, including the compound geometry data, the simple geometry data and the non-geometry data. Also, an example of the feature data model in milling process planning is described.