Game Model of Retailers Leading Closed-Loop Supply Chain under Different Guarantee Modes

—In order to study the retailer-led differentiated guarantee behavior of CLSC's remanufactured products, assuming that demand is influenced by differentiated guarantee period of remanufactured products and consumers' willingness to pay, three game models of unguaranteed, manufacturer's guarantee and retailer's guarantee are constructed respectively to discuss the influence of guarantee mode selection and guarantee cost parameters on each member's decision. The results show that differentiated guarantees for remanufactured products are beneficial to extending the guarantee period, reducing the price of remanufactured products, improving CLSC members and overall profits. When consumers are less sensitive to differentiated guarantee for remanufactured products, CLSC decision in each mode has little to do with guarantee cost parameters and guarantor selection. When consumers are more sensitive, the advantages of each guarantee mode are significantly different, and manufacturer guarantee is the common choice of both parties. Finally, an example is given to further verify the conclusion.

Silver braze corrosion in H2S environment: life assessment and methods of preventing

Issues of using silver as the braze material in H2S environment are discussed due to environment related sulfidation which cause corrosion penetration and risk of compromising seals. To explore risk and mitigation techniques, static H2S high temperature silver braze corrosion tests were conducted. The results are presented and interpreted by Arrhenius equation approach. The corrosion rate decreased with time due to the formation of Ag2S corrosion product layer. This corrosion product changed the chemical reaction type from mass transfer controlled to diffusion controlled. The environment temperature vs braze joint thickness vs guarantee period relationships are shown and discussed. Additionally, possible protection options connected with metallic and non-metallic coating were investigated.

Design and development of tractor clutch using combined field and bench tests

Tractors, the primary component of agricultural mechanization, are actively used for maintaining agricultural activities and carrying burdens on agricultural fields under challenging conditions. Tractors are not only required to possess a high tractive force at low operating speeds but also to produce the power necessary for operating the equipment attached to them when used for agricultural purposes. It is of great importance to determine the degree of force that powertrains, especially the clutch, of the tractors are exposed to on agricultural fields and to use the data obtained in this process concerning their guarantee periods. This study measured the motor rotation speed, clutch surface temperature, and frequency and force of pushing the clutch pedal of a tractor used under five different agricultural field conditions. Furthermore, torque and transfer of the dynamometer and power take-off (PTO) were measured. Based on the data obtained from field tests, the tractor clutch development and validation processes were revised. The prototype clutch was produced and tested by completing the required 1 million rotations safely under new boundary conditions within the guarantee period.

Research on Algorithms of Critical Path Searching and Time Optimization in Construction Projects

Because other consequential damages brought about by the construction delay can not be estimated, so the guarantee period or even ahead of schedule becomes particularly important. The critical path usually determines the progress of the construction. However, because of its own deficiencies, the traditional critical path algorithm cannot accurately describe the overlap between activity and interaction. So, in the paper, matrix method for critical path (CPMM) is designed for CP, and its rules and calculating process are described in detail. Through experiments, the effectiveness of CPMM is proved.

Longevity insurance markets and Money's worth ratios in Korea

The rare annuitization, thin immediate annuity market, and date limitation have prevented the attempts to analyze the longevity insurance market in Korea. The purpose of this paper is to examine the relative value of Korean annuity rates to theoretical ones and to provide a new evidence on the function of the voluntary annuity market in terms of the money's worth ratio (MWR). Our results show that the immediate annuity market in Korea is reasonably efficient. For example, the money's worth ratio of an immediate annuity of a 10-year guarantee period for a 65-year-old male is estimated to be about 0.8 with the general population mortality rate, while it improves to 0.9 with the annuitant mortality table. Average MWR is similar to that of other countries with thin annuity market, which show that annuitants in Korea pay a comparable cost to that in other countries.