• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2006년도 춘계학술대회 논문집
• /
• pp.308-313
• /
• 2006

The effect of coating time on surface properties of the TiN-coated high speed steel(SKH51) by arc ion plating is and presented in this paper. Surface roughness, micro-hardness, coated thickness, atomic distribution of TiN and adhesion strength are measured for various coating times. It has been shown that the coating time has a deep influence more than 60 minites on the micro-hardness, coated thickness, atomic distribution of Ti and adhesion strength of the SKH51 steels, but that the coating time has little influence on the surface roughness.

• 한국기계가공학회지
• /
• 제10권5호
• /
• pp.44-50
• /
• 2011

The effect of deposition time in arc ion plating on surface properties of the TiN-coated SM45C steel is presented in this paper. The surface roughness, micro-particle, micro-hardness, coated thickness, atomic distribution of TiN, and adhesion strength are measured for various deposition times. It has been shown that the deposition time has a considerable effect on the micro-hardness, the coated thickness, and the atomic distribution of TiN of the SM45C steels but that it has little influence on the surface roughness and adhesion strength.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 춘계학술대회 논문집
• /
• pp.540-545
• /
• 1997

This paper is to evaluate the stress distibution and displacements around the single implant restoration in dentisry. The computer simulation technique using FEM was applied to the analysis, and four londing inclination were studied: verical(0 .deg.),15 .deg.,30 .deg.,45 .deg. with respect to implant axis. The magnitudes of occlusal force were 100N, 200N, 300N, 400N, and 500N. The computed result shows that the stress on a single implant restoration increases as the load or the inclined angel increases, and that the change in loading inclination has a greater effect on the stress distribution than that of the load magnitude.

• Journal of the Korean Statistical Society
• /
• 제24권2호
• /
• pp.293-301
• /
• 1995

Sums of independent random variables $S_n = X_1 + \cdots + X_n$ are considered, where the $X_n$ are chosen according to a stationary process of distributions. For $c > 0$, let $t_c$ be the smallest positive integer n such that $$\mid$S_n$\mid$ > cn^{\frac{1}{2}}$. In this set up we are concerned with finiteness of expectation of $t_c$ and we have some results of sign-invariant process as applications.

• Elastomers and Composites
• /
• 제34권4호
• /
• pp.285-291
• /
• 1999

Effects of catalysts on network structure, hard segment length and distribution of polyurethane foams in the absence of catalysts were investigated. CFC free all MDI-based poly urethane foams were prepared from poly(ethylene adipate)glycol, 4,4'-diphenylmethane diisocyanate, and water. Amino catalysts used were 1,4-diazabicyclo[2,2,2]octane(DABCO), N, N,N',N'-tetramethyl--hexane-1,6-diamine(MR), bis(2-methylamino ethyl)ether(ET), 1,8-diazabicyclo-[5,4,0]-undecene-7(DBU). Dibutyltindilaurate(DBTL) as control was also used. Hard segment components of polyurethane foams were obtained by a selective degradation of polyester chains with 0.01N KOH-methanol solution. The PUFs with DBU catalyst contained more amount of isocyanurate components than other PUFs. On the other hand, the PUFs with ET, MR, DBTL catalysts contained more amount of allophanate and biuret component than the other PUFs.

• 대한수학회논문집
• /
• 제37권3호
• /
• pp.765-800
• /
• 2022

Quantization for probability distributions concerns the best approximation of a d-dimensional probability distribution P by a discrete probability with a given number n of supporting points. In this paper, we have considered a probability measure generated by an infinite iterated function system associated with a probability vector on ℝ. For such a probability measure P, an induction formula to determine the optimal sets of n-means and the nth quantization error for every natural number n is given. In addition, using the induction formula we give some results and observations about the optimal sets of n-means for all n ≥ 2.

• Bulletin of the Korean Chemical Society
• /
• 제20권10호
• /
• pp.1200-1204
• /
• 1999

The reactions of Ru(tpy)Cl3 (tpy = 2,2';6',2"-terpyridine) with new N,N,C-terdentate ligands, 3,2'-annulated-6-(2"-pyridyl)-2-phenylpyridines (1, HL) and the properties of their Ru(II) complexes are described. The distribution ratio of the two possible Ru(II) complexes, a pentaaza-coordinated complex [Ru(tpy)(1-N,N')Cl]+ and a cycloruthenated complex [Ru(tpy)(La-N,N',C)]+ are highly dependent on the length of the polymethylene unit. The trimethylene bridge of the N,N,C-terdentate in pentaaza-coordinated complex is rigid enough to induce an asymmetry in the complex.

• 충청수학회지
• /
• 제26권2호
• /
• pp.421-426
• /
• 2013

We give a series of discrete random variables which converges to a random variable whose distribution function is the Riesz-N$\acute{a}$gy-Tak$\acute{a}$cs (RNT) distribution. We show this using the correspondence theorem that if the moments coincide then their corresponding distribution functions also coincide.

• International Journal of Reliability and Applications
• /
• 제10권2호
• /
• pp.63-79
• /
• 2009

A new bivariate linear failure rate distribution is introduced through a shock model. It is proved that the marginal distributions of this new bivariate distribution are linear failure rate distributions. The joint moment generating function of the bivariate distribution is derived. Mixtures of bivariate linear failure rate distributions are also discussed. Application to a real data is given.

• The Korean Journal of Ecology
• /
• 제17권4호
• /
• pp.513-521
• /
• 1994

Distribution patern of 30 species that are occurring predominantly in the mantle communities (Mantelgesellschaften) in South Korea was studied. The study was arried out by geographic and bioclimatic analysis on 368 releves obtained from the Zurich-Montpellier School's method, which involves direct analysis on the latitude, altitude, annual mean temperature and the lowest temperature of the site. Rosa multiflora and Pueraria thunbergiana which are regarded as repersentative pioneer species to the mantle community has the highest frequency, 70.1% and 60.3%, respectively. Three distribution patterns were recognized, i.e. northern type, central type and southern type, and each type was characterized by horizontal and altitudinal amplitude. Their concetrate distribution ranges on the annual mean temperature were 8~11℃, 9~12℃ and 10~13℃, respectively. It was recognized that tendencies of overlapping and continuous distribution pattern of the types and species exist. Geographically, the souther limit f the northern type is 35.5。N and the northern limit of the southern type 37.0。N. The central type is located at an coincided with the previous study in which cool-temperate forests were synchorologically indentified into northern/altimontane, certral/montane and southern/submontane type. The subsidiary knowledges from this study will provide practical information on the constructuin of the fence plant community for environmental conservation.