• The Journal of the Acoustical Society of Korea
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• v.9 no.3
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• pp.48-55
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• 1990

We analyze the effect of second-order sampling on estimating the mean frequency of the Doppler signal. In order to reduce the sampling frequency of analogue-to-digital converter, it is possible to obtain the Doppler signal by sampling the radio frequency echo signal with the low frequence of $4f_0$/5 or $4f_0$/9 instead of $4f_0$, where $f_0$ is the center frequency of the transmitted signal. The computer simulation and experiments show that if the narrowband signal is transmitted as is usual in the Doppler system, the error of the mean frequency estimates due to the low sampling frequency is negligible.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.3
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• pp.162-170
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• 2015

In the bandpass sampling (BPS), the sampling frequency is lower than the frequency of the signal to be sampled. In this method, the baseband spectrum can be directly obtained by the sampling operation. This makes the frequency down converter unnecessary as well as the receiver's circuit simpler. In the second-order BPS system, two sampling devices are used. When aliasing occurs due to the sampling operation, the aliased component can be cancelled by combining the two sampled signals. In this paper, it is presented a design method of the second-order BPS system when multiple interferences are simultaneously aliased to the signal component. The optimum phase of the interpolant filter is searched for maximizing the signal-to-interference ratio, and a practical formula for the suboptimal phase is derived in terms of the power spectrum profile of the BPS input. A computer simulation has been performed for the proposed second-order BPS system, and it has been shown that the signal-to-interference ratio can be increased by considering multiple aliasing.

• Journal of Korean Society for Quality Management
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• v.22 no.3
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• pp.152-160
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• 1994

This paper concerns an expert system for reliability management. The system includes data base, life data analysis, life testing sampling plans and system operation. PROLOG is used as a language with dBASE III+ for the data base management system and C for calculations and graphics. This system analyzing the data and selecting an appropriate sampling plan can be implemented on an IBM PC 386 or a higher level machine.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.269-277
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• 1998

In this study, a traditional concept of sampling inspection plan for the quality assurance system is extended to a consideration of economic aspects in total production system by representing and analyzing the effects between proceding/succeeding production process including inspection. This approach recognizes that the decision to be made at one manufacturing process (or assembly process) determine not only the cost and the average outgoing quality level of that process but also the input parameters of the cost and the incoming quality to the succeeding process. By analyzing the effects of the average incoming and outgoing quality, manufacturing/assembly quality level and sampling inspection plan on the production system, mathematical models and solution technique to minimize the total production cost for a single product manufacturing system with specified average outgoing quality limit (AOQL) are suggested.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.46
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• pp.119-125
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• 1998

In this study, a traditional concept of sampling inspection plan for the quality assurance system is extended to a consideration of economic aspects in total production system by representing and analyzing the effects between proceeding / succeeding production process including inspection. This approach recognizes that the decision to be made at one manufacturing process (or assembly process) determine not only the cost and the average outgoing quality level of that process but also the input parameters of the cost and the incoming quality to the succeeding process. By analyzing the effects of the average incoming and outgoing quality, manufacturing / assembly quality level and sampling inspection plan on the production system, mathematical models and solution technique to minimize the total production cost for a single product manufacturing system with specified average outgoing quality limit(AOQL) are suggested.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.12
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• pp.1960-1963
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• 2021

In this paper, we propose a multiplay Thompson sampling algorithm in multipath communication system. Multipath communication system has advantages on communication capacity, robustness, survivability, and so on. It is important to select appropriate network path according to the status of individual path. However, it is hard to obtain the information of path quality simultaneously. To solve this issue, we propose Thompson sampling which is popular in machine learning area. We find some issues when the algorithm is applied directly in the proposal system and suggested some modifications. Through simulation, we verified the proposed algorithm can utilize the entire network paths. In summary, our proposed algorithm can be applied as a path allocation in multipath-based communications system.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.468-471
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• 1997

In this paper, we investigate the time-sampling effects on the digital implementation of singular perturbation based STT autopilot with excellent performance and propose a compensation method for the time-sampling effects. In digitization of analog STT autopilot, it is found that the stability margin of the fast dynamics is mostly affected to lead to rapid decrease. Under the this analysis, a composite digital controller with additional compensator for fast dynamics is proposed to improve the time-sampling effect and a simulation verifies the result.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.12 no.20
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• pp.77-80
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• 1989

A rectifying sampling plan which assumes a prior distribution on the lot percent defective is considered. This sampling is developed for finite lot size N with matching OC curves and generated from an initial plan selected from single sampling by attributes.

• Communications for Statistical Applications and Methods
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• v.2 no.2
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• pp.358-365
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• 1995

This paper presents another system of multi-level skip-lot sampling plan, which can directly retum to normal inspection from any skpping inspection level when a sudden shift for the worse in the process mean occurs. All the other properties of the proposed sampling plan are similar to those of the Choi's(1993) plan. The formula of the poerating characteristic function for the proposed n-level skip-lot sampling plan is derived. Sone poerating characteristic properties for the proposed plan are graphically compared with those of the Choi's plan.

• Proceedings of the Safety Management and Science Conference
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• 2004.05a
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• pp.145-151
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• 2004

Reliability assurance problem is an important issue in advanced company with good R&D capacity. In Korea, long-term and large-scale project for reliability improvement and certification have been conducted from 2000, 4 years ago. Generally, assurance is composed of system assurance and lot assurance. For reliability lot assurance. it is prerequisite to development reliability sampling plan with time-saving and minimum cost. In this paper, we aim to investigate previous study on reliability lot assurance focused on reliability sampling plans and propose some suggestions for the future study.