• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.6
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• pp.26-34
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• 2008

The information of traversability and path planning is essential for UGV(Unmanned Ground Vehicle) navigation. Such information can be obtained by analyzing 3D terrain. In this paper, we present the method of 3D terrain modeling with color information from a camera, precise distance information from a 2D Laser Range Finder(LRF) and wheel encoder information from mobile robot with less data. And also we present the method of 3B terrain modeling with the information from GPS/IMU and 2D LRF with less data. To fuse the color information from camera and distance information from 2D LRF, we obtain extrinsic parameters between a camera and LRF using planar pattern. We set up such a fused system on a mobile robot and make an experiment on indoor environment. And we make an experiment on outdoor environment to reconstruction 3D terrain with 2D LRF and GPS/IMU(Inertial Measurement Unit). The obtained 3D terrain model is based on points and requires large amount of data. To reduce the amount of data, we use cubic grid-based model instead of point-based model.

• Environmental and Resource Economics Review
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• v.24 no.2
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• pp.435-461
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• 2015

Recently, Korean development Institute includes water for environmental improvement as an additional water demand category in water resources development project. In response to this change, this paper is to measure benefits of providing additional water in Yeondok Ohsip River by applying contingent valuation method. This study extended the conventional CVM design by incorporating distance variable into WTP function of dichotonomous choice responses and treated protest bids by estimating sample-selection models. The empirical analysis exhibited that more than 30% of respondents were categorized as protest bids and the mean of WTP from sample selection models were three times higher than that of the whole sample. In addition, the distance variable had significantly negative impact on sample WTP regardless of variables forms, and the geographical market area were more 400km, which implies that beneficiaries of water service would the households from the whole nation.

• Journal of Game and Entertainment
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• v.2 no.3
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• pp.38-43
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• 2006

As the quality of life increases, the demand for enjoyment of leisure culture is increasing in modem society. This has led to the growth of cultural industries, creating many new cultural industries, and due to its recent engagement with digital technology, the development of digital cultural contents has rapidly expanded. As an integrated art field grafted with high technology, the game industry in particular is fusible with other various fields to create new leisure cultures. Taking these periodic conditions into consideration, this essay has presented a promotion scheme for game culture street based on the characteristics of game culture that make it easy for anyone to access. Game culture material signifies the grafting of cultural game characteristics to the physical platform of street, to provide, not only diverse applications of game culture, but also a market for vitalized game industries. This essay has researched the validity and components of game culture material promotion, along with promotion schemes for physical street.

• 한국지형공간정보학회:학술대회논문집
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• 1993.10a
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• pp.141-145
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• 1993

A new digital change detection algorithm, Euclidean Distance Analysis, was developed in an attempt to utilize the multi-band information in a selected band-comination, as an alternative to the conventional single-band analysis methods. To evaluate the relative performance of this new method, image differencing was applied. The better performance in change detection between the two algorithms investigated was provided by the Euclidean distance analysis. The new technique of Euclidean distance analysis holds promise for change detection, since it summarizes the multiple-band information on the cover-type changes and reduces the data dimensionality. It is suggested to further evaluate this new method, quantitatively, in the different environments. The use of different accuracy indices was also examined in the determining the optimal threshold level for each change image. As the standard measure for classification accuracy, the Kappa coefficient of agreement was used for evaluation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.21-22
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• 2011

In this study, an analytical algorithm for collision avoidance is proposed, which is applicable to designing collision avoidance maneuvers for two encountering ships. The minimum separation distance is defined and an appropriate maneuver sequence is computed for safe and effective collision avoidance. Two approaches: 1) collision avoidance through speed change and 2) collision avoidance through heading change, are considered, and the initiation point of the avoidance maneuver is computed analytically using the geometric configuration of the two encountering ships. To verify the feasibility of the proposed algorithm, numerical simulations are carried out using a set of ship-to-ship encountering scenarios.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06c
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• pp.85-90
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• 2008

최근 유클리드 공간 상에서 효율적인 연속 k-최근접(k-Nearest Neighbors) 질의 처리를 위해 그리드 구조 기반의 많은 색인 기법들이 연구되었다. 하지만 기존 기법들은 k-최근접 객체들을 연산하기 위해 불필요한 셀을 접근하여 연산 자원을 낭비하거나 근접한 셀을 알아내는데 너무 큰 연산 비용을 초래한다. 그래서 본 논문에서는 한 셀과 주변 셀과의 거리 관계 패턴을 이용하여 k-최근접 질의 처리시 적은 연산비용과 적은 저장 공간을 사용하는 새로운 k-최근접 질의 처리 기법을 제안한다. 제안하는 기법은 k-최근접 질의 처리 시 거리 값을 기준으로 정렬된 거리 관계 패턴의 상대좌표를 순차적으로 적용하여 근접한 셀을 알아내기 때문에 O(n)의 셀 검색 비용이 요구된다. 또한 본 논문에서는 CPM[1]과 성능을 비교하여 제안하는 기법의 우수성을 입증한다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.6
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• pp.64-76
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• 2014

This study identified the causes of errors that could take place in the estimation process of vehicle miles traveled and quantified the effects of each of those causes on the estimation accuracy of vehicle miles traveled via error rate to propose an efficient way to estimate vehicle miles traveled. The study proceeded as follows: first, the study established survey data of vehicle miles traveled in the pilot test areas to test the accuracy of a method to estimate vehicle miles traveled. Second, the causes of errors with the estimation of vehicle miles traveled were categorized into errors with the sample size, sampling methods, and homogeneous link setting methods. In addition, many different methodologies were set to minimize errors with the estimation of vehicle miles traveled according to each of the causes. Third, error rates of estimation of vehicle miles traveled were compared and analyzed according to each of the methodologies. Finally, a toy network was established to propose a way of estimating vehicle miles traveled by taking the local characteristics into consideration. The study finds its significance in that it proposed an efficient way to estimate vehicle miles traveled through an experiment and planning approach and made use of survey data of vehicle miles traveled to test estimation accuracy. The proposed way of estimating vehicle miles traveled by taking into account the local characteristics will make a contribution to the estimation of vehicle miles traveled by the areas in future along with the level of data offered in the study.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.4
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• pp.368-378
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• 2022

The purpose of this study was to analyze the accessibility to dental facilities and the differences in chief complaints of new patients who visited Pusan National University Dental Hospital. We collected information from electronic medical records for 1,820 new patients. The accessibility was analyzed by measuring the distance from the patient's house to the dental facilities. The distance was categorized into 10 km sections, and the presence or absence of a local pediatric dental clinic within 10 km of the patient's house was also categorized. As the distance between the house and Pusan National University Dental Hospital increased, the proportion of patients who visited for dental caries decreased, and orthodontic treatment increased. Dental caries accounts for 27.9% of less than 10 km and 20.5% over 30 km. Orthodontic treatment accounts for 25.4% within 10 km and 27.3% more than 30 km away. The presence or absence of a local pediatric dental clinic within 10 km did not significantly affect the distribution of chief complaints. This study can be used as basic research data to establish effective treatment measures that can improve the physical and geographical accessibility of patients visiting pediatric dentistry.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.171-173
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• 2022

The 4th industrial revolution technology is developing people's lives more efficiently. GIS provided on the Internet services such as traffic information and time information makes people getting more quickly to destination. National geographic information service(NGIS) and each local government are making basic data to investigate SOC accessibility for analyzing optimal point. To construct the shortest distance, the accessibility from the starting point to the arrival point is analyzed. Applying road network map, the starting point and the ending point, the shortest distance, the optimal accessibility is calculated by using Dijkstra algorithm. The analysis information from multiple starting points to multiple destinations was required more than 3 steps of manual analysis to decide the position for the optimal point, within about 0.1% error. It took more time to process the many-to-many (M×N) calculation, requiring at least 32G memory specification of the computer. If an optimal proximity analysis service is provided at a desired location more versatile, it is possible to efficiently analyze locations that are vulnerable to business start-up and living facilities access, and facility selection for the public.

• The Transactions of the Korea Information Processing Society
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• v.3 no.6
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• pp.1407-1417
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• 1996

In recent researches on thread partitioning algorithms break a thread at the long latency operation and merge threads to get the longer threads under the given constraints. Due to this limitation, even a program with little parallelism is partitioned into small-sized threads and context-swithings occur frequently. In the paper, we propose another method array localization about the array name, dependence distance(the difference of accessed element index from loop index), and the element usage that indicates whether element is used or defined. Using this information we can allocate array elements to the node where the corresponding loop activation is executed. By array localization, remote accesses to array elements can be replaced with local accesses to localized array elements. As a resuit,the boundaries of some threads are removed, programs can be partitioned into the larger threads and the number of context switchings reduced.