• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1169-1171
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• 2002

In this paper, RFRPP(Random Frequency Randomized Pulse Position ) PWM for three-phase voltage-controlled inverters is proposed. The LLPWM(Lead-Lag PWM) techinquc is that three switching pulses are located randomly back and forth in each switching interval. But with the restriction of random distribution, the harmonic spectrum cannot be dispersedly and continuously distributed. This paper calculates the duty ratio of the switching pulse firstly. Second, the switching pulses are located randomly in the switching interval. Third, the fixed switching frequency of the space vector modulation is randomly varied. To verify the validity of the proposed technique, simulation study is tried using Matlab/Simulink. When a proposed techniquc is employed, the harmonic spectrum of the inverter output voltagc varies from one cycle to the next and the EMI(Electromagnetic Interference) and resonant vibration are greatly alleviated.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.849-852
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• 2006

본 논문은 무선 센서 네트워크 라우팅 프로토콜에서 일어날 수 있는 보안 위협 요소들에 대해 알아보고 상호인증에 관한 문제를 해결할 수 있는 Randomized Path-Hash 노드 인증 프로토콜(RPHAP)을 제안한다. 이 프로토콜은 노드 간 상호인증을 제공하며 센서 추적에 대한 안전성까지 제공한다. 또한 간단한 연산 능력의 Hash를 이용하기 때문에 전력 소모에 대한 오버헤드가 적어 모든 센서 네트워크의 프로토콜에서 활용이 가능한 장점을 갖는다.

• The Korean Journal of Applied Statistics
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• v.19 no.3
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• pp.555-564
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• 2006

Friedman rank-sum multiple comparison procedure is often applied to nonparametric multiple comparison method under randomized block design. Since this method does not use between-block information, we propose, in this paper, nonparametric multiple comparison procedures employing aligned method suggested by Hedges and Lehmann(1962) under randomized block design. The proposed procedure and Friedman procedure are compared by Monte Carlo simulation study.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.4
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• pp.294-300
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• 2004

This paper considers a trade-off effect between in-house storage space and leased storage space in generic warehouses operated under a randomized storage assignment policy. The amount of in-house storage space is determined based on the law of large numbers satisfying a given service level of protection against space shortages. Excess space requirement is assumed to be met via leased storage space. A new analytic model is formulated for determining the excess space such that the total cost of storage space is minimized. Finally, computational results are provided for the systems where the standard economic-order-quantity inventory model is used for all items.

• Communications for Statistical Applications and Methods
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• v.8 no.3
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• pp.731-737
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• 2001

In this paper, we suggest and implement an internet survey system cooperating the randomized response technique(RRT). We compare it with the direct survey. RRT is an indirect survey method to get true information from the respondent who is conceived to have sensitive character without revealing his/her status. We implement our system(method) based a data-base system, so it common all kind of data obtained through internet surveys. This system also can be used in spot survey independently.

• The Korean Journal of Applied Statistics
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• v.25 no.3
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• pp.447-456
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• 2012

For a sensitive survey in which the population is comprised of several clusters with a quantitative attribute, we present an additive quantitative randomized response model by cluster sampling that adapts a two-stage cluster sampling instead of a simple random sample based on Himmelfarb-Edgell's additive quantitative attribute model and Gjestvang-Singh's one. We also derive optimum values for the number of 1st stage clusters and the optimum values of observation units in a 2nd stage cluster under the condition of minimizing the variance given constant cost. We can see that Himmelfarb-Edgell's model is more efficient than Gjestvang-Singh's model under the condition of cluster sampling.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1401-1408
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• 2013

Kim and Kim (1992) proposed typical nonparametric method for umbrella alternative in randomized block design with replications. In this paper, We consider a test procedure for umbrella alternatives in a randomized block design using extension of the two sample placement tests described in Orban and Wolfe (1982) and treatment tests described in Kim (1999). We perform a Monte Carlo study to compare the empirical powers of the test statistics for underlying distributions.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.347-354
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• 2002

In this paper, a comparative study on the performance of two-phase and three-phase randomized pulse position PWM scheme for mitigation of audible switching acoustic noise in motor drives Is done. In the randomized pulse position PWM, each of two-phase or three-phase PWM pulses is located randomly in each switching interval. Simulation and experimental efforts were executed to investigate the spread effects of power spectra of inverter output voltage, waveforms of ripple current and audible switching acoustic noise.

• Proceedings of the Safety Management and Science Conference
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• 2012.04a
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• pp.277-292
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• 2012

The research presents an application of Balanced ANOVA (BANOVA) by utilizing randomized orders for various Split-Plot Designs (SPDs) which include two cell designs, split-plot with one-way HTC (Hard to Control) factor, split-plot with two-way HTC factor, split-split-plot design and nested design. In addition, four MINITAB examples of 2-level split-plot designs based on the number of blocks and the type of whole-plots are presented for practitioners to obtain comprehensive understanding. Furthermore, the geometrical interrelated properties among three typical Designs of Experiments (DOE), such as Factorial Design (FD), Response Surface Design (RSD), and Mixture Design (MD) are discussed in this paper.

• Journal of Acupuncture Research
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• v.22 no.4
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• pp.189-195
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• 2005

Objectives : This study was to evaluate the effectiveness of Bee Venom acupuncture therapy on sprain of C-spine by randomized controlled double blinding method. Methods : A randomized double blinding study of bee venom acupuncture therapy was conducted on sprain of C-spine. We divided sprain of C-spine patient into 2 groups: one group with both acupuncture and saline acupuncture therapy, and another group with both acupuncture and bee venom acupuncture therapy. To estimate the efficacy of treatment that applied for two groups, we used visual analog scale(VAS) and neck disability index(NDI). We compared the VAS and NDI score of two groups statistically. Results : STZ induced increase of serum creatinine, BUN and albumin secretion were lowered by AD-1 treatment.