• Aerospace Engineering and Technology
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• v.8 no.2
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• pp.26-32
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• 2009

In the satellite image fusion, the most important point is to preserve both the spatial detail of panchromatic(PAN) image and the spectral information of multispectral(MS) image. Among various image fusion techniques, fusion technique using Intensity-Hue-Saturation(IHS) transform is widely used and it has advantage that computation is very simple. In this study, a fusion technique using fast IHS transform and trade-off parameter $\alpha^i$ proposed. Proposed fusion technique permits customization of the trade-off between the spectral information and spatial detail quality of the fused image through the evaluation of two quality indices: a spectral index(the spectral ERGAS) and a spatial one(the spatial ERGAS). Based on the result of experiment using IKONOS image, we confirmed the proposed fusion technique was more effective in preserving spatial detail and spectral information than existing fusion techniques using fast IHS transform.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.334.2-334
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• 2002

In conventional model updating using single-objective optimization techniques, imcompatible physical data are compared with each other using weighting factors. There are no general rules fur selecting the weighting factors since they are not directly related with the dynamic behavior of an updated model. So one of the most difficult tasks, in mr)del updating study, is 'balancing among the correlations', i.e. 'trade-off'. (omitted)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.295-300
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• 2002

In conventional model updating using single-objective optimization techniques, incompatible physical data are compared with each other using weighting factors. There are no general rules for selecting the weighting factors since they are not directly related with the dynamic behavior of an updated model. So one of the most difficult tasks, in model updating study, is 'balancing among the correlations' i.e. 'trade-off'. In this work, a multiobjecitive optimization technique called 'satisficing trade-off method' is introduced to extremize several correlations simultaneously. The absurd need for the weighting factors can be avoided using this technique. And the updated model with the most appropriate correlations is obtained easily in interactive way. Especially automatic trade-off is employed to increase the rate of convergence to the desired model. Its effectiveness is verified by application to a real engineering problem, HDD cover model updating.

• Architectural research
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• v.11 no.2
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• pp.43-49
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• 2009

Since the late 1980s, the schedule technique applied to the construction industry around the world has rapidly changed from the traditional ADM (Arrow Diagramming Method) to the PDM (Precedence Diagramming Method) technique. The main reason for this change is to overcome the limits and inconveniences of the traditional ADM technique. The time-cost trade-off is one of the core scheduling techniques to establish the best optimized combination plan in terms of a relationship between the cost and schedule. However, most of the schedule-related textbooks and research papers have discussed and proposed applications of a time-cost trade-off technique based only on the Finish to Start relationship. Therefore, there are almost no consideration and discussion of problems or restrictions that emerge when the time-cost trade-off technique is applied to the PDM network that has overlapping relationships. This paper proposes the lead-time adjustment method as a methodology for overcoming some restrictions that are encountered when the time-cost trade-off technique is applied to the overlapping relationships of the PDM network.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.24-29
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• 1999

The purpose of this study is to develop a method of applying response surface analysis to trade-off techniques for the conceptual design of armored vehicle. The problem areas of concern are the use of this method in the selection of optimum design points when user requirements are in conflict. The application of this method to trade-offs of performance parameters in terms of weight are presented.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.66-75
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• 2000

The purpose of this study is to develop and illustrate methods of applying trade-off techniques to landing craft air cushion design evaluation. The problem areas of concern are the application of quantitative analytical methods to conceptual design. The interrelationships between composite system measures and selected performance requirements(speed, cruising range, cargo etc.) are analyzed and the expressions for gross weight are developed as functions of performance parameters. Trade-offs of performance parameters in terms of weight are then calculated. The application of these results to evaluation of Require Operational Capabilities are illustrated.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.4
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• pp.293-304
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• 2020

In this paper, various modulation techniques, including the legacy Global Navigation Satellite System (GNSS) signal modulation techniques, are introduced and the spectral characteristics and correlation characteristics of signals with various modulation techniques are analyzed based on numerical simulation. With the development of various GNSS services, the limited frequency band has become increasingly saturated, and issues of interoperability and compatibility have emerged in the new GNSS design. Since the efficient allocation of frequency resources is closely related to spectrum design, modulation techniques are one of the important signal design parameters of new signal design. Signal modulation techniques are closely related to various figure of merits (FoMs) as well as spectrum characteristic, and in some cases there is a complicated trade-off between FoMs. Thus, the FoMs associated with modulation technology should be analyzed and the best signal candidates should be chosen carefully via the trade-off analysis for FoMs. In this paper, we define the modulation technique based on Phase Shift Keying (PSK), Binary Offset Carrier (BOC) and Continuous Phase Modulation (CPM) for the design of KPS signals, and the FoMs of signals in terms of spectrum and correlation function are evaluated. Signals with various modulation techniques are implemented through a numerical simulation, and the relevant FoMs are analyzed.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.4
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• pp.219-230
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• 2011

The nuclear fuel cycle (NFC) analysis is a study to set a NFC policy and to promote systematic researches by analyzing technologies and deriving requirements at each stage of a fuel cycle. System analysis techniques are utilized for comparative analysis and assessment of options on a considered system. In case that NFC is taken into consideration various methods of the system analysis techniques could be applied depending on the range of an interest. This study presented NFC analysis strategies for the development of a domestic advanced NFC and analysis techniques applicable to different phases of the analysis. Strategically, NFC analysis necessitates the linkage with technology analyses, domestic and international interests, and a national energy program. In this respect, a trade-off study is readily applicable since it includes various aspects on NFC as metrics and then analyzes the considered NFC options according to the derived metrics. In this study, the trade-off study was identified as a method for NFC analysis with the derived strategies and it was expected to be used for development of an advanced NFC. A technology readiness level (TRL) method and NFC simulation codes could be utilized to obtain the required metrics and data for assessment in the trade-off study. The methodologies would guide a direction of technology development by comparing and assessing technological, economical, environmental, and other aspects on the alternatives. Consequently, they would contribute for systematic development and deployment of an appropriate advanced NFC.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.3
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• pp.1-7
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• 1999

In this research, transformation-based optimization techniques for pipelined designs have been developed. The transformation-based optimization techniques include pipelined architecture transformations and retiming transformations. The new transformation method has the following three features. First, the overall performance of a pipelined system is optimized owing to various transformations including retiming of multiple pipelined blocks. Second, these techniques can be used to search a large solution space by allowing efficient exploration of trade-offs between area and performance. Third, these techniques can be easily extended to a new transformation or algorithm and can be used to optimize memory or bus architectures. Experimental results illustrate that these transformation-based optimization techniques improve area by 21% and performance by 17% on the average for a set of pipelined designs. Especially, the techniques are useful to efficiently explore a large design space.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.2
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• pp.9-20
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• 2020

The study investigates a recent surge of cash literature by using a sample of hospitality firms to gain a new understanding of corporate cash holdings. Past literature states that there is a substantial variation of liquidity across industry groups. Existing literature predominantly refers to US-listed firms and focus on either hotels or restaurants and not the hospitality industry as a whole. Therefore, we provide a comparative study of cash holdings behaviour between hospitality and non-hospitality firms from an emerging market context. Using a sample of public listed hospitality firms from 2002 to 2013, dynamic panel regression techniques are used to study the relationships between firm characteristics and cash levels. Also, the non-parametric Wilcoxon-Mann-Whitney test was carried out to examine the time and sectoral differences in cash holdings. In addition, the panel regression techniques are used to investigate the relationships between firm characteristics and level of corporate cash holdings. The results reveal that firm characteristics do matter in hospitality firms. We find that firm size, capital expenditures, and liquid assets substitutes are negatively related to cash level. The results support trade-off theory and the pecking order theory. This study incrementally explains the cash holdings behaviour of hospitality firms in emerging market.