• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.312-312
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• 2011

All ship's ballast water should be inspected by administration after enter into force IMO BWM Convention. The purpose of the sampling device is to concentrate large amount of samples and to improve return rate of samples. It is composed of Concentration and Rinsing Part and optimized by the variety of tests. it is fully automated and therefore efficiently operated in ships.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.2
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• pp.33-40
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• 2010

In this paper, we consider three macroscopic traffic flow monitoring indices, Travel Time Index(TTI), Acceleration Noise(AN) and Two Fluid(TF) and investigate how to determine a proper rate of probe cars for producing reliable values of these indices. For the analysis, we use classical sampling theories and provide numbers of probe rates using simulation data.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.2
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• pp.221-225
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• 2008

In this paper, to avoid the frequency analysis requiring a high sampling rate, time-warped similarity measure algorithms, which are able to classify objects even with a low-rate sampling rate as time- series methods, are presented and proposed the DTW-Cosine algorithm, as the best classifier among them in wireless sensor networks. Two problems, local time shifting and spatial signal variation, should be solved to apply the time-warped similarity measure algorithms to wireless sensor networks. We find that our proposed algorithm can overcome those problems very efficiently and outperforms the other algorithms by at least 10.3% accuracy.

• Journal of Veterinary Clinics
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• v.29 no.1
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• pp.63-67
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• 2012

Mosquitoes are the vectors of a number of viral diseases in cattle, such as Akabane disease, bovine ephemeral fever, Ainovirus infection, Chuzan virus infection, and Ibaraki disease. These diseases are transmitted from an infected animal to a non-infected host via the blood feeding of the vector. In Korea, the National Veterinary Research and Quarantine Services, Ministry for Food, Agriculture, Forestry and Fisheries is responsible for planning, implementation, laboratory investigations and reporting the results of the national surveillance program for mosquito-borne bovine diseases (MBD). The surveillance program, which was started in 1993, focused to determine the seroprevalence of each disease in cattle herds in space and time. From the epidemiological point of view, more important component of the surveillance program is to monitor infection rates in vectors for specific pathogens because this information is essential for a more precise understanding the dynamics of these diseases in a given environment and for determining risk of transmission. The aim of this study was to describe and compare methods for estimation of vector infection rates using maximum likelihood (MLE) and minimum infection rate in pooled samples. Factors affecting MLE such as number of pools, pooling size and diagnostic test performance are also discussed, assuming some hypothetical sampling scenarios for MBD.

• Journal of Information Technology Services
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• v.16 no.3
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• pp.103-111
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• 2017

The real time scheduling is a key research area in high performance computing and has been a source of challenging problems. A periodic task is an infinite sequence of task instance where each job of a task comes in a regular period. The RMS (Rate Monotonic Scheduling) algorithm has the advantage of a strong theoretical foundation and holds out the promise of reducing the need for exhaustive testing of the scheduling. Many real-time systems built in the past based their scheduling on the Cyclic Executive Model because it produces predictable schedules which facilitate exhaustive testing. In this work we propose hybrid scheduling method which combines features of both of these scheduling algorithms. The original rate monotonic scheduling algorithm didn't consider the uniform sampling tasks in the real time systems. We have enumerated some issues when the RMS is applied to our hybrid scheduling method. We found the scheduling bound for the hard real-time systems which include the uniform sampling tasks. The suggested hybrid scheduling algorithm turns out to have some advantages from the point of view of the real time system designer, and is particularly useful in the context of large critical systems. Our algorithm can be useful for real time system designer who must guarantee the hard real time tasks.

• Journal of Communications and Networks
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• v.14 no.2
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• pp.188-194
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• 2012

Cognitive networks (CNs) are capable of enabling dynamic spectrum allocation, and thus constitute a promising technology for future wireless communication. Whereas, the implementation of CN will lead to the requirement of an increased energy-arrival rate, which is a significant parameter in energy harvesting design of a cognitive user (CU) device. A well-designed spectrum-sensing scheme will lower the energy-arrival rate that is required and enable CNs to self-sustain, which will also help alleviate global warming. In this paper, spectrum sensing in a multi-user cognitive ad hoc network with a wide-band spectrum is considered. Based on the prospective spectrum sensing, we classify CN operation into two modes: Distributed and centralized. In a distributed network, each CU conducts spectrum sensing for its own data transmission, while in a centralized network, there is only one cognitive cluster header which performs spectrum sensing and broadcasts its sensing results to other CUs. Thus, a wide-band spectrum that is divided into multiple sub-channels can be sensed simultaneously in a distributed manner or sequentially in a centralized manner. We consider the energy consumption for spectrum sensing only of an analog-to-digital convertor (ADC). By formulating energy consumption for spectrum sensing in terms of the sub-channel sampling rate and whole-band sensing time, the sampling rate and whole-band sensing time that are optimal for minimizing the total energy consumption within sensing reliability constraints are obtained. A power dissipation model of an ADC, which plays an important role in formulating the energy efficiency problem, is presented. Using AD9051 as an ADC example, our numerical results show that the optimal sensing parameters will achieve a reduction in the energy-arrival rate of up to 97.7% and 50% in a distributed and a centralized network, respectively, when comparing the optimal and worst-case energy consumption for given system settings.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.185-190
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• 2007

In this paper, minimum sampling rates and method of nonlinear characterization were suggested for low power, quasi-memoryless PAs. So far, the Nyquist rate of the input signal has been used for nonlinear PA modeling, and it is burdening Analog-to-digital converters for wideband signals. This paper shows that the input Nyquist rate sampling is not a necessary condition for successful modeling of quasi-memoryless PAs. Since this sampling requirement relives the bandwidth requirements for Analog-to-digital converters (ADCs) for feedback paths in digital pre-distortion systems, relatively low-cost ADcs can be used to identify nonlinear PAs for wideband signal transmission, even at severe aliasing conditions. Simulation results show that a generic memoryless nonlinear RF power amplifier with AMAM and AMPM distortion can be successfully identified at any sampling rates. Measurement results show the modeling error variation is less than 0.8dB over any sampling rates.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.2
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• pp.147-159
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• 1997

One of the most critical problems associated with filter-pack data comparisons from various field networks is the use of different sampling flow rates. In this field study, the effects of various filter-pack(FP) sampling conditions were examined. Experiments were conducted to evaluate the effects of varying sampling flow rates (1.5 to 10 sLpm) on measured concentrations of dry acid deposition species. Collocated FP samples were also collected to determine sampling and analysis data reproducibility. Ambient air samples were collected simultaneously for the seven day durations at varous flow rate. The chemical species measured were sulfur dioxide ($SO_2$), particulate sulfate(P-$SO_{4}^{2+}$), nitric acid ($HNO_3$), and particulate nitrate (P-$NO_{3}^{-}$). The results indicated that the collocated samples can be measured reproducibly and that sampling bias for the species measured is not significant. It was concluded that variations in the flow rates (1.5 to 10 sLpm) did not significantly affect the concentration of the species of interest. Although the results were not significantly different between different flow rates, artifacts were more likely to occur at high flow conditions (>5 sLpm) (e.g., via volatilization of particulate nitrates) than at low flow conditions(<5 sLpm).

• Journal of Preventive Medicine and Public Health
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• v.42 no.2
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• pp.135-142
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• 2009

Objectives : An appropriate sampling strategy for estimating an epidemiologic volume of diabetes has been evaluated through a simulation. Methods : We analyzed about 250 million medical insurance claims data submitted to the Health Insurance Review & Assessment Service with diabetes as principal or subsequent diagnoses, more than or equal to once per year, in 2003. The database was re-constructed to a 'patient-hospital profile' that had 3,676,164 cases, and then to a 'patient profile' that consisted of 2,412,082 observations. The patient profile data was then used to test the validity of a proposed sampling frame and methods of sampling to develop diabetic-related epidemiologic indices. Results : Simulation study showed that a use of a stratified two-stage cluster sampling design with a total sample size of 4,000 will provide an estimate of 57.04%(95% prediction range, 49.83 - 64.24%) for a treatment prescription rate of diabetes. The proposed sampling design consists, at first, stratifying the area of the nation into "metropolitan/city/county" and the types of hospital into "tertiary/secondary/primary/clinic" with a proportion of 5:10:10:75. Hospitals were then randomly selected within the strata as a primary sampling unit, followed by a random selection of patients within the hospitals as a secondly sampling unit. The difference between the estimate and the parameter value was projected to be less than 0.3%. Conclusions : The sampling scheme proposed will be applied to a subsequent nationwide field survey not only for estimating the epidemiologic volume of diabetes but also for assessing the present status of nationwide diabetes control.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.1
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• pp.22-28
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• 2015

This paper proposes column-parallel three step Single Slope Analog-to-Digital Converter (SS-ADC) for high frame rate VGA CMOS Image Sensors (CISs). The proposed three step SS-ADC improves the sampling rate while maintaining the architecture of the conventional SS-ADC for high frame rate CIS. The sampling rate of the three-step ADC is increased by a factor of 39 compared with the conventional SS-ADC. The proposed three-step SS-ADC has a 12-bit resolution and 200 kS/s at 25 MHz clock frequency. The VGA CIS using three step SS-ADC has the maximum frame rate of 200 frames/s. The total power consumption is 76 mW with 3.3 V supply voltage without ramp generator buffer. A prototype chip was fabricated in a $0.13{\mu}m$ CMOS process.