• Progress in Medical Physics
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• v.28 no.4
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• pp.144-148
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• 2017

When a high density metallic implant is placed in the path of the proton beam, spatial heterogeneity can be caused due to artifacts in three dimensional (3D) computed tomography (CT) scans. These artifacts result in range uncertainty in dose calculation in treatment planning system (TPS). And this uncertainty may cause significant underdosing to the target volume or overdosing to normal tissue beyond the target. In clinical cases, metal implants must be placed in the beam path in order to preserve organ at risk (OARs) and increase target coverage for tumors. So we should introduce Ti-mesh. In this paper, we measured the lateral dose profile for proton beam using an EBT3 film to confirm dosimetric impact of Ti-mesh when the Ti-mesh plate was placed in the proton beam pathway. The effect of Ti-mesh on the proton beam was investigated by comparing the lateral dose profile calculated from TPS with the film-measured value under the same conditions.

• Industrial Engineering and Management Systems
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• v.7 no.3
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• pp.245-256
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• 2008

In order to cope with the ill-defined problem of human behavior being immanent uncertainty, several methodologies have been studied in game theoretic, social psychological and political science frameworks. As methods to arrange system elements systematically and draw out the consenting structural model concretively, ISM, FSM and DEMATEL based on graph theory etc. have been proposed. In this paper, we propose a modified structural modeling method to recognize the nature of problem. We introduce the statistical method to adjust the establishment levels in group decision situation. From this, it will become possible to obtain effectively and smoothly the structural model of group members in comparison with the traditional methods. Further we propose a procedure for achieving the consenting structural model of group members based on the structural modeling method. By applying the method to recognize the nature of ill-defined problems, it will be possible to solve the given problem effectively and rationally. In order to inspect the effectiveness of the method, we conduct a practical problem as an empirical study: "Behavior analysis of passengers for the Joban line of East Japan Railway Company after new railway service of Tsukuba Express opened".

• Journal of Korea Technology Innovation Society
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• v.1 no.3
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• pp.285-298
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• 1998

Innovation with strategic interaction is to overcome the technological uncertainty and to create co-evolution through competition among individuals or organizations for the acceleration of innovation. The concept of innovation in the past was concentrated on cooperation rather than on competition for the efficient management of limited resources. However, in order to minimize the technological uncertainty, we need an innovation on the basis of competition between organizations. Competition stimulates technological adaptability. It is on the analogy of complex system. This is to satisfy consumers' needs, to transform the resources into a technology, and to apply for the development of new products and new technologies. If the emergence of a new technology threatens present technology and develops into a new level of technology through inter-relation, it becomes a mutually supporting technologies. When theses effects are simultaneously realized, it is possible for firm to have strategical innovation and to create a mutually evolutionary development. Furthermore, when the competition among more than two individuals or two organizations continues towards the same direction, the mutual competition and cooperation can be expected to create a synergy effect. The competitive environment should be composed of R&D, production, and consumers' choice. This will lead to interaction among organizations through strategic competition and cooperation. Intra-firm competition and Inter-firm competition are required to exist together.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.6
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• pp.922-928
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• 2006

An absolute absorption cross section of benzene was measured with a spectrometer system including a mono-chrometer and a grating in the wavelength region of $240{\sim}280nm$ under the atmospheric pressure and room temperature in the laboratory. A certificated reference benzene gas ($98{\mu}mol/mol$ in $N_2$) was used to measure its absorption cross section. A 710 mm cell with a quartz window and a 150 W Xe arc lamp were employed. The magnitude of absorption cross section of $1.41{\times}10^{-18}cm^2$ was lower than that of the reference spectra ($2.5{\times}10^{-18}cm^2$) of high resolution spectrometer, Total measurement uncertainty was estimated to be 4.0%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1084-1087
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• 2002

The guard-ring type 3-terminal parallel plate electrodes proposed by ASTM D 150-81 and IEC 250 have been widely used for measurement of dielectric constants of solid dielectrics. However the method using this electrodes causes many uncertainty associated with the measurement errors of the diameter of the guarded electrode. the gap between guarded and guard-ring electrode. the distance of two active electrodes(the thickness of specimen), the roughness and contamination of surface of electrode and specimen. close adherence grade of electrode and specimen. In this paper. a new electrode system of cross capacitance type based on Thompson-Lampard theorem is designed and is employed for the measurement of dielectric constant. The results of simulation of guard-ring electrode and cross capacitance electrode using FEM program show that distance measurement between two electrodes in guard-ring electrode produces large uncertainty. on the other hand this effect in cross capacitance electrode is negligible. Furthermore. the air gap effects in the cross capacitance electrode is 5.6 times less sensitive than that in guard-ring electrode by assuming air gap of $50{\mu}m$.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.162-165
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• 2004

The authors' previous study found an interannual covariability between actual evapotranspiration (ET) and the Normalized Difference Vegetation Index (NDVI) over northern Asia. This result suggested that vegetation controls interannual variation in ET. In this prior study, NDVI data from the Pathfinder AVHRR Land (PAL) dataset were analyzed. However, studies of NDVI interannual change are subject to uncertainty, because NDVI data often contain errors associated with sensor- and atmosphere-related effects. This study is aimed toward reducing this uncertainty by employing NDVI dataset, from the Global Inventory Monitoring and Modeling Studies (GIMMS) group, in addition to PAL. The analysis was carried out for the northern Asia region from 1982 to 2000. 19-year interannual change in PAL-NDVI and GIMMS-NDVI were both compared with interannual change in model-assimilated ET. Although the correlation coefficient between GIMMS-NDVI and ET is slightly less than for PAL-NDVI and ET, for both NDVI datasets the annual maximum correlation with ET occurs in June, which is near the central period of the growing season. A significant positive correlation between GIMMS-NDVI and ET was observed over most of the vegetated land area in June as well as PAL-NDVI and ET. These results reinforce the authors' prior research that indicates the control of interannual change in ET is dominated by interannual change in vegetation activity.

• International Journal of Control, Automation, and Systems
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• v.4 no.4
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• pp.448-455
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• 2006

This paper deals with the observer design problem for a class of state-delayed nonlinear systems with or without time-varying norm-bounded parameter uncertainty. The nonlinearities under consideration are assumed to satisfy the global Lipschitz conditions and appear in both the state and measured output equations. The problem we address is the design of a nonlinear observer such that the resulting error system is globally asymptotically stable. For the case when there is no parameter uncertainty, a sufficient condition for the solvability of this problem is derived in terms of linear matrix inequalities and the explicit formula of a desired observer is given. Based on this, the robust observer design problem for the case when parameter uncertainties appear is considered and the solvability condition is also given. Both of the solvability conditions obtained in this paper are delay-dependent. A numerical example is provided to demonstrate the applicability of the proposed approach.

• Journal of IKEEE
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• v.20 no.4
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• pp.439-448
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• 2016

RTDs and thermocouple sensors are broadly used to measure its temperature in industry and research. The contents of this standard calibration procedure(SCP) describe procedures related to the calculation of Electrical Temperature Calibrator and show different ways to indicate the calibration results like the uncertainty in measurement. As of current, SCP of electrical temperature calibrator has not been established yet and we have some inconveniences and difficulties in the standard calibration work. To solve these problems, we have studied the calibration technique for RTD and thermocouple of temperature calibrator. In this paper, we present the mathematic model of its data and variations of measurement with the results of calibration data.

• Smart Structures and Systems
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• v.17 no.3
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• pp.445-470
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• 2016

In this study, the Bayesian probabilistic framework is investigated for modal identification and modal identifiability based on the field measurements provided in the structural health monitoring benchmark problem of an instrumented cable-stayed bridge named Ting Kau Bridge (TKB). The comprehensive structural health monitoring system on the cable-stayed TKB has been operated for more than ten years and it is recognized as one of the best test-beds with readily available field measurements. The benchmark problem of the cable-stayed bridge is established to stimulate investigations on modal identifiability and the present paper addresses this benchmark problem from the Bayesian prospective. In contrast to deterministic approaches, an appealing feature of the Bayesian approach is that not only the optimal values of the modal parameters can be obtained but also the associated estimation uncertainty can be quantified in the form of probability distribution. The uncertainty quantification provides necessary information to evaluate the reliability of parametric identification results as well as modal identifiability. Herein, the Bayesian spectral density approach is conducted for output-only modal identification and the Bayesian model class selection approach is used to evaluate the significance of different modes in modal identification. Detailed analysis on the modal identification and modal identifiability based on the measurements of the bridge will be presented. Moreover, the advantages and potentials of Bayesian probabilistic framework on structural health monitoring will be discussed.

• The Journal of Information Systems
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• v.27 no.3
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• pp.161-180
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• 2018

Purpose One of the success factors of information system projects is to reduce requirements uncertainty through user engagement. So, in many recent IS development environment, a business analyst or business analysts are positioned between users and developers to drive user engagement to reduce requirements uncertainty. But, there are few studies that research about the competencies of business analysts for training and staffing. So, this study analyzed which underlying and practical competencies that positively influence user engagement are required. Design/methodology/approach The level of underlying and practical competencies required for business analysts and the level of user enagement in the IS development environment are collected through the survey. And, the causal relationship between the construct concepts which are underlying competencies, practical competencies and the user participation is analzed through the PLS analysis. Findings The results of this study show that the practial competencies of business analysts that positively have a significant impact on user engaement were studied as requirements development skills. Additionally, the underlying competencies of business analysts which have a significant impact on requirements development skills were examined as business knowledge and interaction skills rather than technical knowledge and communication skills.