• Journal of applied mathematics & informatics
• /
• 제37권5_6호
• /
• pp.351-355
• /
• 2019

We obtain two characterizations of uniform distribution based on ratios of upper record values by the properties of independence and identical distribution.

• 한국해안해양공학회지
• /
• 제14권4호
• /
• pp.282-285
• /
• 2002

본 연구에서 선형파 이론을 사용하여 파랑변형을 예측할 경우 소멸파 성분의 역학적인 크기를 정량화 하는 작업을 하였다. 즉, 진행파 성분뿐만 아니라 소멸파의 영향을 받는성분의 운동에너지와 위치에너지를 유도하였다. 소멸파 성분에는 진행파와 소멸파의 합성 성분, 서로 같은 소멸파의 합성 성분, 서로 다른 소멸파의 합성 성분으로 구성되어 있다. 수평길이 당 소멸파의 에너지 성분은 수명길이가 커짐에 따라 기하급수적으로 감소한다.

• Journal of Communications and Networks
• /
• 제1권2호
• /
• pp.111-117
• /
• 1999

Using a method recently reported in the literature for analyzing the bit error probability (BEP) performance of noncoherent Mary orthogonal signals with square-law combining in the presence of independent and identically distributed Nakagami-m faded paths, we are able to reformulate this method so as to apply to a generalized fading channel in which the fading in each path need not be identically distributed nor even distributed ac-cording to the same family of distribution. The method leads to exact expressions for the BEP in the form of a finite-range integral whose integrand involves the moment generating function of the combined signal-to-noise ratio and which can therefore be readily evaluated numerically. The mathematical formalism is illustrated by applying the method to some selected numerical examples of interest showing the impact of the multipath intensity profile (MIP) as well as the fading correlation profile (FCP) on the BEP performance of M-ary orthogonal signal over Nakagami-m fading channels. Thses numerical results show that both MIP and FCP induce a non-negligible degradition in the BEP and have therefore to be taken into account for the accurate prediction of the performance of such systems.

• 대한전자공학회논문지SP
• /
• 제48권2호
• /
• pp.134-140
• /
• 2011

압축 센싱 (Compressed Sensing) 기술을 통해 $M{\times}N$ 측정 행렬의 원소들이 특정의 독립적인 확률 분포에서 뽑혀 identically 분포의 성질을 가지고 있을 때 $M{\ll}N$의 경우에도 스파스 (sparse) 신호를 높은 확률로 정확하게 복원할 수 있다. $L_1$-최소화 알고리즘이 불완전한 측정에 대해서도 스파스 (sparse) 신호를 복원할 수 있다는 것은 잘 알려진 사실이다. 본 논문에서는 OMP를 변형시킨 support 검출과 가중치 기법을 이용한 $L_1$-최소화 방법을 통하여 스파스 (sparse) 신호의 복원 성능을 향상시키는 알고리즘을 제안하고자 한다.

• Journal of applied mathematics & informatics
• /
• 제27권3_4호
• /
• pp.829-842
• /
• 2009

Let {$X_{ni}|1\;{\le}\;i\;{\le}\;n$, $n\;{\ge}\;1$} be an array of rowwise negatively associated random variables and let $\alpha$ > 1/2, 0 < p < 2 ${\alpha}p\;{\ge}\;1$. In this paper we discuss $n^{{\alpha}p-2}h(n)$ max $_{1\;{\le}\;k{\le}n}\;|\;{\sum}^k_{i=1}\;X_{ni}|/n^{\alpha}\;{\to}\;0$ completely as $n\;{\to}\;{\infty}$ under not necessarily identically distributed with a suitable conditions and h(x) > 0 is a slowly varying function as $x\;{\to}\;{\infty}$. In addition, we obtained that $n^{{\alpha}p-2}h(n)$ max $_{1\;{\le}\;k{\le}n}\;|\;{\sum}^k_{i=1}\;X_{ni}|/n^{\alpha}\;{\to}\;0$ completely as $n\;{\to}\;{\infty}$ if and only if $E|X_{11}|^ph(|X_{11}|^{1/\alpha})\;<\;{\infty}$ and $EX_{11}\;=\;0$ under identically distributed case and some corollaries are obtained.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권11호
• /
• pp.4623-4643
• /
• 2015

This paper considers physical-layer security protocols in multicast cognitive radio (CR) networks. In particular, we propose dual-hop cooperative decode-and-forward (DF) and randomize-and-forward (RF) schemes using partial relay selection method to enhance secrecy performance for secondary networks. In the DF protocol, the secondary relay would use same codebook with the secondary source to forward the source's signals to the secondary destination. Hence, the secondary eavesdropper can employ either maximal-ratio combining (MRC) or selection combining (SC) to combine signals received from the source and the selected relay. In RF protocol, different codebooks are used by the source and the relay to forward the source message secretly. For each scheme, we derive exact and asymptotic closed-form expressions of secrecy outage probability (SOP), non-zero secrecy capacity probability (NzSCP) in both independent and identically distributed (i.i.d.) and independent but non-identically distributed (i.n.i.d.) networks. Moreover, we also give a unified formula in an integral form for average secrecy capacity (ASC). Finally, our derivations are then validated by Monte-Carlo simulations.

• Journal of the Korean Statistical Society
• /
• 제10권
• /
• pp.97-104
• /
• 1981

It is shown that a lattice distribution defined on a set of n lattice points $L(n,\delta) = {\delta,\delta+1,...,\delta+n-1}$ is a distribution induced from the distribution of convolution of independently and identically distributed (i.i.d.) uniform [0,1] random variables. Also the m-th moment of the lattice distribution is obtained in a quite different approach from Park and Chung (1978). It is verified that the distribution of the sum of n i.i.d. uniform [0,1] random variables is completely determined by the lattice distribution on $L(n,\delta)$ and the uniform distribution on [0,1]. The factorial mement generating function, factorial moments, and moments are also obtained.

• Journal of the Korean Statistical Society
• /
• 제13권2호
• /
• pp.87-106
• /
• 1984

It ${X_t}$ is a sequence of independent identically distributed normal random variables, then the conditional probability density of $X_1, X_2, \cdots, X_n$ given the first p+1 sample autocovariances converges to the maximum entropy probability density satisfying the corresponding covariance constraints as the length of the sample sequence tends to infinity. This establishes that the maximum entropy probability density and the associated Gaussian autoregressive process arise naturally as the answers of conditional limit problems.

• Journal of applied mathematics & informatics
• /
• 제30권3_4호
• /
• pp.647-653
• /
• 2012

In this paper, we consider fuzzy random sets as (measurable) mappings from a probability space into the set of fuzzy sets and prove a uniform strong law of large numbers for sequences of independent and identically distributed fuzzy random sets. Our results generalize those of Bass and Pyke(1984)and Jang and Kwon(1998).

• 충청수학회지
• /
• 제26권2호
• /
• pp.269-273
• /
• 2013

We prove a characterization of the power function distribution by lower record values. We prove that $F(x)=(\frac{x}{a})^{\alpha}$ for all $x$, 0 < $x$ < $a$, ${\alpha}$ > 0 and $a$ > 0 if and only if $\frac{X_{L(n)}}{X_{L(m)}}$ and $X_{L(m)}$ are independent for $1{\leq}m$ < $n$.