• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.6-11
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• 1994

For a safety supervision, watching a restricted area so that no one go there is very important. This has been mostly accomplished by people. They keep an eye on many monitors at onece for a long time. It, however, is too simple and boring to concentrate it for a long time. So it's worth while to construct a watching system by image processing. And the system we made is now actually working at a certain hydroelectric power plant and some other restricted areas in Japan.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.6
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• pp.497-502
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• 2015

One of the goals in the field of mobile robotics is the development of personal service robots for the elderly which behave in populated environments. In this paper, we describe a security robot system and ongoing research results that minimize the risk of the elderly and the infirm to access an area to enter restricted areas with high potential for falls, such as stairs, steps, and wet floors. The proposed robot system surveys a potential falling area with an equipped laser scanner sensor. When it detects walking in elderly or infirm patients who in restricted areas, the robot calculates the velocity vector, plans its own path to forestall the patient in order to prevent them from heading to the restricted area and starts to move along the estimated trajectory. The walking human is assumed to be a point-object and projected onto a scanning plane to form a geometrical constraint equation that provides position data of the human based on the kinematics of the mobile robot. While moving, the robot continues these processes in order to adapt to the changing situation. After arriving at an opposite position to the human's walking direction, the robot advises them to change course. The simulation and experimental results of estimating and tracking of the human in the wrong direction with the mobile robot are presented.

• Journal of Advanced Navigation Technology
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• v.3 no.1
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• pp.69-90
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• 1999

The Korean airspace is very much limited, but its users are many. Especially many special using airspaces for military aircraft are formulated within the Taegu Flight Information Region and it is so restricted for civil aircraft to use the military airspaces. However, as the demand of civil air traffic is increasing, positive cooperation among the users of the airspace is needed to cope with the demand and to uplift the utilitation of the Korean airspace. Most of airspace except airways within the FIR are restricted areas, prohibited areas or operation areas for the military purpose. This thesis shows how to improve the utilitation of the Korean airspace and how much economical benefit the suggestion gives.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.49-55
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• 2004

The manoeuvring of vessels and hydrodynamic interaction between them and bank wall in restricted waterways have been treated as important factors in channel design and safe piloting in the water areas. This paper examines the interaction forces and moments acting on two vessels running closely in the proximity if bank wall. The object if this paper is to propose a guideline of safe velocity if vessels and distance between them for navigating safely in confined sea areas.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.17-22
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• 2005

The manoeuvring of vessels and hydrodynamic interaction between them and bank wall in restricted waterways have been treated as important factors in channel design and safe piloting in the waterway areas. This paper examines the interaction forces and moments acting on two vessels running closely in the proximity of bank wall. The object of this paper is to propose a guideline of safe velocity of vessels and distance between them for navigating safely in confined sea areas.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.3
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• pp.57-62
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• 2012

In this study, changes depending on the Airparks for LSA(Light Sport Aircraft) and Ultralight vehicle flight restricted areas, the flight route for LSA in Korea was redesigned. Considerations for LSA operating limits of VFR and complex airspace conditions in Korea, and that links the Airparks for LSA is to redesign the proposed.

• Communications for Statistical Applications and Methods
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• v.29 no.5
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• pp.547-559
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• 2022

For a chi-squared test, which is a statistical method used to test the independence of a contingency table of two factors, the expected frequency of each cell must be greater than 5. The percentage of cells with an expected frequency below 5 must be less than 20% of all cells. However, there are many cases in which the regional expected frequency is below 5 in general small area studies. Even in large-scale surveys, it is difficult to forecast the expected frequency to be greater than 5 when there is small area estimation with subgroup analysis. Another statistical method to test independence is to use the Bayes factor, but since there is a high ratio of data dependency due to the nature of the Bayesian approach, the low expected frequency tends to decrease the precision of the test results. To overcome these limitations, we will borrow information from areas with similar characteristics and pool the data statistically to propose a pooled Bayes test of independence in target areas. Jo et al. (2021) suggested hierarchical Bayesian pooling models for small area estimation of categorical data, and we will introduce the pooled Bayes factors calculated by expanding their restricted pooling model. We applied the pooled Bayes factors using bone mineral density and body mass index data from the Third National Health and Nutrition Examination Survey conducted in the United States and compared them with chi-squared tests often used in tests of independence.

• Communications for Statistical Applications and Methods
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• v.26 no.4
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• pp.371-383
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• 2019

Panel data sets have been developed in various areas, and many recent studies have analyzed panel, or longitudinal data sets. Maximum likelihood (ML) may be the most common statistical method for analyzing panel data models; however, the inference based on the ML estimate will have an inflated Type I error because the ML method tends to give a downwardly biased estimate of variance components when the sample size is small. The under estimation could be severe when data is incomplete. This paper proposes the restricted maximum likelihood (REML) method for a random effects panel data model with a censored dependent variable. Note that the likelihood function of the model is complex in that it includes a multidimensional integral. Many authors proposed to use integral approximation methods for the computation of likelihood function; however, it is well known that integral approximation methods are inadequate for high dimensional integrals in practice. This paper introduces to use the moments of truncated multivariate normal random vector for the calculation of multidimensional integral. In addition, a proper asymptotic standard error of REML estimate is given.

• Journal of the Korean housing association
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• v.17 no.1
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• pp.77-84
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• 2006

Government uses some sections of intended areas of abolition in Development Restricted Zones(DRZ) to construct a million national rental houses. It has been opposed by environmental NGOs, local governments and land owners. Therefore, government carried out a questionnaire survey to make plans for the better development of housing estates for national rental houses in DRZ. The results of the survey are as follows: First, using abolished DRZ has to be kept to a minimum, though the continued construction of this kind of houses is inevitable. Second, it has to be designed using pro-environmental techniques. Third, the discussion between the interested groups was not enough. Fourth, residents were dissatisfied with the compensation package. The policies based on this research, are as follows: First, meetings for projects presentation and public hearings have to be held on a regular basis. In addition, the consultative council with residents, local NGOs, and local governments should be combined. Second, The plan should promote social integration through the mixing of rental and owner-occupied houses. Third, a compensation policy, which offers land or houses, and not only cash, needs to be introduced.

• Imaging Science in Dentistry
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• v.30 no.4
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• pp.259-263
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• 2000

Purpose: Upper cervical vertebrae are commonly imaged together with the jaw bones in panoramic radiography. There have been many studies investigating the possible role of mandible as an indicator of osteoporosis. But the result doesn't show unanimity. This study measured bone densities of mandible and second and third cervical vertebrae to find out any relationship between these two areas. These results may contribute in panorama being used as a screening method in detecting possible osteoporotic patient. Materials and Methods: Randomly selected 226 digitized panoramic images with cervical vertebrae shadows from 156 dental patients between 5 to 80 years of age were used. And the bone densities of second and third cervical vertebrae, apical areas of first and second mandibular molars and interdental areas were measured. The bone density measurements were restricted to the cancellous bone and the average and standard deviations and paired t-tests were done to each measurements. Results: All the measurements were statistically significantly related. The best relationship was found between the third cervical vertebrae and first and second mandibular apical areas. The average and standard deviations of the measured bone density ratios of these areas were 1.20±0.45 and 1.34±0.48 each. Conclusion: Patients whose panoramic bone density of the third cervical vertebrae are much below those of mandibular first or second molar apical areas may have osteoporosis.