• Journal of Biosystems Engineering
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• v.38 no.1
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• pp.18-24
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• 2013

Purpose: This study was conducted to develop an optimal combine scheduling program using Max-Coverage algorithm which derives the maximum efficiency for a specific location in harvest seasons. Methods: The combine scheduling program was operated with information about combine specification and farmland. Four operating types (Max-Coverage algorithm type, Boustrophedon path type, max quality value type, and max area type) were selected to compare quality and working capacity. Result: The working time of Max-Coverage algorithm type was shorter than others, and the total quality value of Max-Coverage algorithm and max quality value type were higher than others. Conclusion: The developed combine scheduling program using Max-Coverage algorithm will provide optimal operation and maximum quality in a limited area and time.

• International Journal of Quality Innovation
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• v.5 no.1
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• pp.110-121
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• 2004

There is a new trend of incorporating software coverage metrics into software reliability modelling. This paper proposes a coverage-based software reliability growth model. Firstly, the failure rate function in coverage is analytically derived. Then it is shown that the number of detected faults follows a Nonhomogeneous Poisson distribution of which intensity function is the failure rate function in coverage. Practical applicability of the proposed models is examined by illustrative numerical examples.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.5014-5034
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• 2016

This paper discusses how to effectively guarantee the coverage and connectivity quality of wireless sensor networks when joint perception model is used for the nodes whose communication ranges are multi-level adjustable in the absence of position information. A Connect Coverage Algorithm Based on Joint Sensing model (CCAJS) is proposed, with which least working nodes are chosen based on probability model ensuring the coverage quality of the network. The algorithm can balance the position distribution of selected working nodes as far as possible, as well as reduce the overall energy consumption of the whole network. The simulation results show that, less working nodes are needed to ensure the coverage quality of networks using joint perception model than using the binary perception model. CCAJS can not only satisfy expected coverage quality and connectivity, but also decrease the energy consumption, thereby prolonging the network lifetime.

• Korean Management Science Review
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• v.26 no.3
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• pp.67-78
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• 2009

In this paper, I analyze the mobile broadband services market characterized by vertical and horizontal differentiation. Vertical differentiation as service quality differentiation is based on the transmission speed of mobile internet service and horizontal differentiation as spatial differentiation is based on the service coverage. Theoretical explanations for the competitive price policy have been developed in the game context of WiBro which represent the high quality within the limited service coverage and HSDPA which represent relatively low quality with nation-wide service. When the WiBro has a mobile broadband service quality advantage and the difference in quality is sufficiently low, the price of WiBro with limited service coverage is relatively lower than that of HSDPA. This occurs because the advantage of WiBro's vertical service differentiation is offset by the disadvantage of horizontal differentiation. The difference in the quality of mobile internet service, however, is not too high, the price of WiBro is relatively higher than that of HSDPA. Moreover, when the service quality of WiBro is sufficiently high, the low quality HSDPA service faces no demand.

• Journal of Communications and Networks
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• v.16 no.5
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• pp.493-501
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• 2014

Coverage completeness is an important indicator for quality of service in wireless sensor networks (WSN). Due to limited energy and diverse working conditions, the sensor nodes have different lifetimes which often cause network holes. Most of the existing methods expose large limitation and one-sidedness because they generally consider only one aspect, either coverage rate or energy issue. This paper presents a novel method for coverage hole detection with residual energy in randomly deployed wireless sensor networks. By calculating the life expectancy of working nodes through residual energy, we make a trade-off between network repair cost and energy waste. The working nodes with short lifetime are screened out according to a proper ratio. After that, the locations of coverage holes can be determined by calculating the joint coverage probability and the evaluation criteria. Simulation result shows that compared to those traditional algorithms without consideration of energy problem, our method can effectively maintain the coverage quality of repaired WSN while enhancing the life span of WSN at the same time.

• Journal of the Korean Society of Radiology
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• v.13 no.5
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• pp.683-689
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• 2019

We are trying to evaluate usefulness of Wide Coverage Volume Axial Mode by comparing and analyzing for exposure doses to patients and video quality extracted from two materials. First material is a computer tomography scanning of paediatric cardiac made by using High Pitch Mode, which is designed for diagnosing Congenital cardiac diseases. Second material is computer tomography scanning of paediatric cardiac made by using Wide Coverage Volume Axial Mode. When we did computer tomography scanning of paediatric cardiac, we used High Pitch Mode and Wide Coverage Volume Axial Mode to 50 patients of each, overall 100 patients. Also, we compared exposure doses to patients using videos got from each protocol. Then we compared video quality by calculating SNR and CNR by setting ROI of each. Not only exposure doses to patients were reduced by 13.07 %, but also SNR and CNR were improved when testing used Wide Coverage Volume Axial Mode rather than using High Pitch Mode. Wide Coverage Volume Axial Mode reduced testing time by using high-speed scanner. Furthermore, we can find out that Wide Coverage Volume Axial Mode is an useful method through improving video quality and reducing exposure doses to patients than using High Pitch Mode from ASiR-V, which is low-dose technology.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.325-328
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• 2001

This paper describes a VHDL code coverage checker for If design and verification. Applying the verification coverage to IP design is a methodology rapidly gaining popularity. This enables the designers to improve the IP design quality and reduces the time-to-market by providing the Quantitative measure of simulation completeness and test benches. To support this methodology, a VHDL code coverage model was defined and the measurement tool was developed.

• Korean Journal of Radiology
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• v.21 no.1
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• pp.58-67
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• 2020

Objective: Third-generation dual-source computed tomography (3rd-DSCT) allows dynamic myocardial CT perfusion imaging (dynamic CTP) with a 10.5-cm z-axis coverage. Although the increased radiation exposure associated with the 50% wider scan range compared to second-generation DSCT (2nd-DSCT) may be suppressed by using a tube voltage of 70 kV, it remains unclear whether image quality and the ability to quantify myocardial blood flow (MBF) can be maintained under these conditions. This study aimed to compare the image quality, estimated MBF, and radiation dose of dynamic CTP between 2ndDSCT and 3rd-DSCT and to evaluate whether a 10.5-cm coverage is suitable for dynamic CTP. Materials and Methods: We retrospectively analyzed 107 patients who underwent dynamic CTP using 2nd-DSCT at 80 kV (n = 54) or 3rd-DSCT at 70 kV (n = 53). Image quality, estimated MBF, radiation dose, and coverage of left ventricular (LV) myocardium were compared. Results: No significant differences were observed between 3rd-DSCT and 2nd-DSCT in contrast-to-noise ratio (37.4 ± 11.4 vs. 35.5 ± 11.2, p = 0.396). Effective radiation dose was lower with 3rd-DSCT (3.97 ± 0.92 mSv with a conversion factor of 0.017 mSv/mGy∙cm) compared to 2nd-DSCT (5.49 ± 1.36 mSv, p < 0.001). Incomplete coverage was more frequent with 2nd-DSCT than with 3rd-DSCT (1.9% [1/53] vs. 56% [30/54], p < 0.001). In propensity score-matched cohorts, MBF was comparable between 3rd-DSCT and 2nd-DSCT in non-ischemic (146.2 ± 26.5 vs. 157.5 ± 34.9 mL/min/100 g, p = 0.137) as well as ischemic myocardium (92.7 ± 21.1 vs. 90.9 ± 29.7 mL/min/100 g, p = 0.876). Conclusion: The radiation increase inherent to the widened z-axis coverage in 3rd-DSCT can be balanced by using a tube voltage of 70 kV without compromising image quality or MBF quantification. In dynamic CTP, a z-axis coverage of 10.5 cm is sufficient to achieve complete coverage of the LV myocardium in most patients.

• Journal of Korean society of Dental Hygiene
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• v.15 no.6
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• pp.1107-1116
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• 2015

Objectives: The purpose of this study was to examine awareness and satisfaction toward health insurance coverage of scaling. Methods: A self-reported questionnaire was completed by 221 patients receiving scaling service from July to August, 2014. The informed consent was approved after the explanation of purpose of the study. The questionnaire consisted of general characteristics of the subjects, awareness toward health insurance coverage of scaling, scaling service covered by health insurance, and satisfaction with health insurance service. Results: Those recognizing the health insurance service extension accounted for 87.3 percent and 67.4 percent answered that the appropriate coverage age would be 20 years old. The recommendable frequency of scaling was once a year and this accounted for 49.3 percent. Fifty percent of the subjects thought health insurance coverage of scaling would be reasonable and 34.8 percent acquired the information from mass media. The most common service providers were dental hygienists and the length of service was from 20 to 30 minutes. The contents of service included scaling service, toothbrushing method, and oral care. The satisfaction was 4.39 points. Conclusions: The health insurance coverage of scaling will improve the oral health and quality of life in Korean adults. So the government should try to extend the scaling coverage by health insurance and the frequency of scaling.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3621-3640
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• 2016

In the process of k-coverage of the target node, there will be a lot of data redundancy forcing the phenomenon of congestion which reduces network communication capability and coverage, and accelerates network energy consumption. Therefore, this paper proposes a novel energy balanced k-coverage control algorithm based on probability model (EBKCCA). The algorithm constructs the coverage network model by using the positional relationship between the nodes. By analyzing the network model, the coverage expected value of nodes and the minimum number of nodes in the monitoring area are given. In terms of energy consumption, this paper gives the proportion of energy conversion functions between working nodes and neighboring nodes. By using the function proportional to schedule low energy nodes, we achieve the energy balance of the whole network and optimizing network resources. The last simulation experiments indicate that this algorithm can not only improve the quality of network coverage, but also completely inhibit the rapid energy consumption of node, and extend the network lifetime.