• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.4
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• pp.67-77
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• 2010

Growth of oil and chemical industries has been remarkable during recent years. Hazardous materials (Hazmat) make frequent use in the wide range of industries. It increases the frequency of Hazmat transport and it leads to increase the number of accidents. Optimal Hazmat routes can reduce damage. Thus, the objective of this study is to minimize the areas impacted by Hazmat accidents by adopting experts' opinion in planning the route. We calculated weights using AHP (Analytic Hierarchy Process) and deduced the best route by applying this weights. Results showed that in the case of shortest route versus weighted route, the percentage of population damage has been decreased by 33.4% in the comparison between shortest route and optimally weighted route. And the percentage of environmental damage also has been decreased by 21.8%. Social damage has been decreased by 1521.7%. In the case of none weighted route versus weighted route, the percentage of population damage has been decreased by 2.6% when we adopted weighted route. Consequently, the recommended route with weighted risk assessment avoids densely populated area comparing with none weighted route. Further research needs to be carried out in order to figure out the specific cost-effectiveness analysis applying the equal cost unit for each factor.

• Speech Sciences
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• v.9 no.1
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• pp.49-59
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• 2002

This paper concerns an effective text-dependent speaker verification method to increase the performance of speaker verification. While various speaker verification methods have already been developed, their effectiveness has not yet been formally proven in terms of achieving acceptable performance levels. This paper proposes a weighted likelihood procedure along with a confidence measure based on subword-based text-dependent speaker verification. Our aim is to remedy the low performance problem in speaker verification by exploring a means to strengthen the verification likelihood via subword-based hypothesis criteria and weighted likelihood method. Experimental results show that the proposed speaker verification method outperforms that of the speaker verification scheme without using the proposed decision by a factor of up to 1.6 times. From these results, the proposed speaker verification method is shown to be very effective and to achieve a reliable performance.

• Journal of Ocean Engineering and Technology
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• v.13 no.4 s.35
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• pp.82-97
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• 1999

A deep sea vehicle must be designed to ensure its safety under ultra-high pressure circumstances. If a pressure housing of a deepsea vehicle is collapsed by ultra-high pressure, the deepsea vehicle may be lost. The objective of this paper is to introduce a design collapse pressure for the deep sea pressure vessel which is composed of one cylinder and two hemispheres. Especially the collapse pressure of hemispherical shell with a hole at top is analyzed by a variational approach (weighted residual method). And for the purpose of design, the salty factor of collapse pressure is presented which is analyzed by interpolation method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.1
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• pp.45-61
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• 2010

In the communication channel, the received signal is affected by many factors that can cause errors. These effects mean that received signal strength (RSS) based methods incur more errors in measuring distance and consequently result in low precision in the location detection process. As one of the approaches to overcome these problems, we propose using direction calibration to improve the performance of the RSS-based method for distance measurement, and sequentially a weighted least squares (WLS) method using reliability factors in conjunction with a conventional RSS weighting matrix is proposed to solve an over-determined localization process. The proposed scheme focuses on the features of the RSS method to improve the performance, and these effects are proved by the simulation results.

• Journal of Korean Neurosurgical Society
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• v.37 no.3
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• pp.241-243
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• 2005

We report a case of recurrent dermatofibrosarcoma in a 30-years-old woman who had undergone operations three times during 60 months and had received post-operative radiotherapy. On neurological examination, no neurological deficits were noticed. In brain magnetic resonance image(MRI), there was right parieto-occipital scalp mass with high signal in T2-weighted image, low signal in T1-weighted image with homogeneous enhancement. The removal was done including about 2cm uninvolved margins and pathologic examination of the lesion revealed dermatofibrosarcoma protuberans(DFSP). The prognostic factors of local recurrence may be related to surgical margins for resection; the length from the grossly intact margins, and the microscopically controlled excision in margins.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.39.3-39
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• 2002

In this paper, presented is a feedback control loop, for an in-plane gimbaled micro gyroscope based on methodology and state weighted model reduction technique. The micro gyroscope is the basic inertial sensors. To improve the performances such as stability, wide dynamic range, bandwidth and especially robustness, it is necessary to design a feedback control loop, which must be robust, because the manufacturing process errors can be large. Especially, to obtain wide bandwidth, the feedback controller is indispensable, because the gyroscope is high Q factor system and has small open loop bandwidth. Moreover, the feedback controller reduces the effect...

• The Korean Journal of Applied Statistics
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• v.21 no.4
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• pp.621-630
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• 2008

This paper discusses how to construct a generalized marginal logit model for analyzing repeated polytomous response data when some factors are applied to larger experimental units as treatments and time to a smaller experimental unit as a repeated measures factor. So, two different experimental sizes are considered. Weighted least squares(WLS) methods are used for estimating fixed effects in the suggested model.

• Journal of the Korea Society for Simulation
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• v.14 no.3
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• pp.137-146
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• 2005

In parametric approach to a signature verification, it generally uses so many redundant features unsuitable for each individual signature that it causes harm, instead. This paper proposes a method of determining personalized weights of a feature set in signature verification with parametric approach by identifying the characteristics of each feature. For an individual signature, we define a degree of how difficult it is for any other person to forge the one's (called 'DFD' as the Degree of Forgery Difficulty). According to the statistical characteristics and the intuitional characteristics of each feature, the standard features are classified into four types. Four types of DFD functions are defined and applied into the distance calculation as a personalized weight factor. Using this method, the error rate of signature verification is reduced and the variation of the performance is less sensitive to the changes of decision threshold.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.73-76
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• 2002

In this paper, we consider an algorithm for effectively providing data services for mobile users with different levels of priorities in a DS-CDMA system. The priority level of a user is specified by a factor that is a weighting on the instantaneous data throughput of the user. We define tile weighted instantaneous aggregate data throughput and use it to characterize the performance of the prioritized data service. Our prioritized data service is implemented so that the weighted instantaneous aggregate data throughput is maximized via efficient power and spreading gain allocation. We present efficient algorithms for computing tile optimal power and spreading gain allocation.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2088-2090
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• 2003

A practical recursive weighted least square(WLS) solution is proposed to solve the passive ranging problem. Apart from the previous works based on the extended Kalman filter(EKF), to ensure the convergency at long-range, the proposed scheme makes use of line-of-sight(LOS) rate instead of bearing information. The influence of LOS rate measurement errors is investigated and it is asserted that the WLS estimates contain bias and scale factor errors. Together with simple compensation algorithm, the estimation errors of proposed filter can be reduced dramatically.