• Composites Research
• /
• 제29권5호
• /
• pp.282-287
• /
• 2016

p-DCPD (poly dicyclopentadiene) is the resin that the versatile mechanical properties can be changeable via the control of inner monomer and catalysts. In this work, to improve the strength of composites, surface treated MGF (milled glass fiber) was used as an reinforcement in p-DCPD by molybdenum (Mo) catalyst matrix. The optimum concentration of surface treatment was obtained and the cohesion of MGF themselves increased with concentration. In case of 0.2 wt% silane concentration, the maximized mechanical properties of MGF/p-DCPD composite exhibited because of minimized MGF cohesion. When butyl silane showing minimizing cohesion was used as the optimized alkyl length, high tensile and flexure strength exhibited due to the steric hindrance effect among MGFs. Mechanical and their fractured surfaces of MGF/p-DCPD composites was compared for 4 different chemical functional groups. Norbornene functional groups containing similar chemical structure to DCPD matrix exhibited higher interfacial adhesion between MGFs and DCPD matrix.

• International Journal of Reliability and Applications
• /
• 제7권1호
• /
• pp.13-25
• /
• 2006

A new class of life distributions is studied. This class is defined based on comparing the residual life time to the whole life in the moment generating function order giving 'the new better than used in the moment generating function order ageing class $(NBU_{mgf})$'. Fundamental properties of this class are given including some closure properties and characterizations. Finally, we consider new results about comparisons of age and block replacement policies when the underlying distribution belongs to $NBU_{mgf}$ aging classes.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• 제48권8호
• /
• pp.1-6
• /
• 2011

In this paper, another analytical approach for dual-hop amplify-and-forward(AF) relay systems is proposed over Rayleigh fading channels. Previous approaches derived the moment generating function(MGF) by using the cumulative distribution function(CDF) or probability density function(PDF) of the received signal-to-noise ratio(SNR) for source-relay-destination(S-R-D) link. Then, the average symbol error rate is expressed based on derived MGFs. In this paper, another new approach is proposed. It means that the MGF is directly derived by utilizing PDFs of both source-relay(S-R) and relay-destination(R-D) links. Additionary, the newly derived MGF is compared and analyzed with previous ones. Furthermore, simulation results are presented to validate the accuracy of proposed analytical expression. Based on this, it is confirmed that the proposed analytical approach can be a another solution for dual-hop AF relay systems.

• International Journal of Reliability and Applications
• /
• 제13권2호
• /
• pp.57-69
• /
• 2012

Our goal in this paper is to establish inequalities for the moments of new better than used in the moment generating function class ($NBU_{mgf}$). Using these inequalities we propose a new test for exponentiality versus $NBU_{mgf}$ class. Pitman's asymptotic relative efficiency, power and critical values of this test are calculated to assess the performance of the test. We proposed also a new test for exponentiality versus $NBU_{mgf}$ in the right censored data. Sets of real data are used as an example to elucidate the use of the proposed test for practical problems.

• International Journal of Reliability and Applications
• /
• 제17권2호
• /
• pp.107-119
• /
• 2016

A new concept of aging classes namely new better (worse) than used at age $t_0$ in moment generating function order, $NBU_{mgf}-t_0$ ($NWU_{mgf}-t_0$) is introduced. For the classes $NBU_{mgf}-t_0$ ($NWU_{mgf}-t_0$), preservation under convolution, mixture, mixing and the homogeneous Poisson shock model are studied. In the sequel, nonparametric test is proposed, the asymptotic normality of the class is established and the asymptotic null variance is estimated. The percentiles and powers of this test are tabulated. The asymptotic efficiencies for some alternatives distributions are derived. Finally sets of real data are used as examples to elucidate the use of the proposed test in practical application.

• Elastomers and Composites
• /
• 제22권3호
• /
• pp.204-212
• /
• 1987

The purpose of this study is to investigate the reinforced effect between MGF treated silane coupling agents and rubber matrix under the configuration chemical bonds, also the effect of triazine thiol compounds. For this study, vulcanizates were prepared with fifteen different compounding formulas. Their vulcanization characteristics, physical properties were examined by means of the ODR(Oscillating Dist Rheometer), the tensile tester, the benzene swelling test. The results of this study obtained are as follows: 1. In the ODR test, the MA vulcanizate was the fastest one in terms of having reached to optimum cure time($t_{90}$) and, with the same formula, when MGF vulcanizates, the shortest optimum cure times has appeared. 2. The SA, SC vulcanizates were the best the other in the physical properties such as 100%modulus, 200%modulus, 300%modulus, tensile strength. The SB vulcanizate, with higher density of crosslinking than other vulcanizates. The vulcanizates, which were filled with MGF treated with silane coupling agents we were the higher density of crosslinking than vulcanizates filled with MGF only. 3. In aging properties, the silica vulcanizates appeared to be better than the other vulcanizates. The aging Properties of treated MGF vulcanizates were similar to the silica vulcanizates. The(CR+APS+silica) and(CR+APS+MCF) were easily crosslinked by exposure to the air, and the physical properties have been improved.

• International Journal of Reliability and Applications
• /
• 제5권4호
• /
• pp.155-162
• /
• 2004

A new class of life distributions is studied. This class is defined based on comparing the residual life to the whole life in the moment generating function order giving "the new better than used in the moment generating function order ageing class ($NBU_{mgf}$)". Some new results of this class are given including some closere properties and characterizations. Finally testing exponentially against the $NBU_{mgf}$ class is also addressed.

• Food Science of Animal Resources
• /
• 제24권4호
• /
• pp.355-360
• /
• 2004

In Korean beef market, one of the major problems is mislabeling or fraudulent distribution of Holstein dairy meat or imported beef as domestic Hanwoo meat. Therefore, there has been a great need for a development of technology to identify beef breeds in meat and meat products. This study was carried out to develop the accurate and reliable method for the identification of beef breed using PCR-RFLP marker of MC1R, MGF and TYRPl genes affecting coat colors in cattle. A single base substitution (G\longrightarrowT transition) at the codon for amino acid position 104 of MC1R gene was identified between Hanwoo and Holstein and Angus breeds. The change at this position creates Msp I restriction site in Holstein and Angus, but not in Hanwoo. When the DNA amplified products (537 bp) was digested with Msp I, Hanwoo meat showed a single band of 537bp, while two fragments of 329bp and 208 bp were observed in Holstein meat and Angus breed, respectively. Thus, breed-specific RFLP marker in the MC1R gene can be used to distinguish between Hanwoo meat and Holstein and Angus meats. In the RFLP genotype of MGF gene, the frequency of r/r type was 75％ in Manwoo, whereas the frequency of R/R was 80％ in Hereford breed. Holstein and Angus breeds showed 100％ for R/r type. Therefore, Hanwoo meat showed significant difference in the MGF genotype frequencies compared with those of Holstein meat and imported beef cattle breeds. However, TYRP1 gene showed the same genotype in all breeds examined. Thus, this TYRP1 gene can not be used as a molecular marker for breed identification. As a consequence, we suggest that RFLP markers of the MC1R and MGF coat color genes could be used as DNA marker for identification of Hanwoo meat from Holstein and imported meats.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• 제49권4호
• /
• pp.1-8
• /
• 2012

This paper presents a method for obtaining an exact average symbol error rate (ASER) of M-ary Phase Shift Keying (MPSK) for opportunistic amplify-and-forward (OAF) relay systems over Rayleigh fading channels. This is based on the relay selection probability when a relay is selected as the best one with respect to the received signal-to-noise ratio. We then derive the modified moment generating function (MGF) for OAF relay systems by taking the given relay selection probability into consideration. Based on the modified MGF, we derive the exact ASER which accurately explicates OAF relay system characteristics. Our results confirm that the derived ASER provides a tight upper bound for OAF relay systems.

• Journal of Powder Materials
• /
• 제21권2호
• /
• pp.124-130
• /
• 2014

The automotive industry is moving from the internal combustion engine to electric drive motors. Electric motors uses a high voltage system requiring the development of resources and components to shield the system. Therefore, in this study, we analyze electromagnetic interference (EMI) shielding effectiveness (SE) characteristics of an auto crash pad according to the ratio of electrically conductive materials and propylene. In order to combine good mechanical characteristics and electromagnetic shielding of the automotive crash pad, metal-coated glass fiber (MGF) manufacturing methods are introduced and compared with powder-type methods. Through this study, among MGF methods, we suggest that the chopping method is the most effective shielding method.