• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.80-83
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• 1999

An efficient modeling and management of a large amount of surface data for a wide rage of geographic information play an important role in determining the functionality of 3D geographic information system. It has been put many efforts to design and manage an effective way to enhence the manipulation of the data by considering geometry type and data structures. Recently, DEM(Data Elevation Model) and TIN(Triangulated Irregular Network) are used for representing surface data. In this paper, we propose a 3D data processing method. The method utilizes the major properties of DEM and TIN, respectively. Furthermore, by approximating DEM with a TIN of an appropriate resolution, we can support a fast and realistic surface modeling. We implement the structure with the following 4 level stages. The first is an optimal resolution of DEM which represent all of wide range of geographic data. The second is the full resolution DEM which is a subarea of original data generated by user's selection in our implemeatation. The third is the TIN approximation of this data with a proper resolution determined by the relative position with the camera. And the last step is multi-resolution TIN data whose resolution is dynamically decided by considering which direction user take notice currently. Specially, the TIN of the last step is designed for realtime camera navigation. By using the structure we implemented realtime surface clipping, efficient approximation of height field and the locally detailed surface LOD(Level of Detail). We used the initial 10-meter sampling DEM data of Seoul, KOREA and implement the structure to the 3D Virtual GIS based on the Internet.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.1257-1264
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• 2009

In regard to media contents of digital heritage reconstruction, they are actively produced in museums, art galleries and special exhibitions. However, there is no concrete guideline for the productions and the pipelines are not systematic either. This makes the process ineffective regarding time and cost. Media contents production of digital heritage reconstruction might seem similar to film or documentary production, but it is important to construct its specific pipeline based on its specific purpose. The digital Heritage group in research center for culture technology of KAIST produced media contents which digitally reconstructed various heritages such as Persepolis, Iranian remains, with National museum of Korea, Sukgulam, and Hue, an ancient city in Vietnam, with Cultural heritage administration of Korea. From these experiences and case studies, this paper will present a pipeline model for efficient production.

• The KIPS Transactions:PartC
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• v.12C no.5 s.101
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• pp.709-716
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• 2005

QoS is an important requirement of the FTTH (Fiber To The Home) subscriber in access network using E-PON (Ethernet Passive Optical Network). In this research, we describe the structure of the access network and propose a bandwidth guarantee scheme for subscriber and service according to the requirements of the subscriber, service and system. This scheme uses two kinds of the classification table, which are called 'service classification table' and 'subscriber classification table.' Using the classification table, we can identify the flow of the subscriber and service. Also, we compute the number of hash table entry to minimize the loss ratio of flows using the M/G/k/k queueing model. Finally, we apply the DRR scheduling through virtual queueing per subscriber instead of the aggregated class.

• The Transactions of the Korea Information Processing Society
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• v.3 no.7
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• pp.1697-1706
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• 1996

This paper presents the design and the implementation of a MissCW(Multi user Interactive System for Synchronous Collaborative Writing). The document model DMDA(Distributed Multimedia Document Architecture) of MissCW consists of the logical structure, presentation style object, and mark object. The windows. The collaborative editor of this system proposes a structure oriented editing mechanism to combine distrbuted objects into one document. The middleware SOM(Shared Object Manager) maintains shared objects consistently and helps application programs use objects efficiently. The infrastructure of this system is a hybrid structure of replicated and centralized architectures, that is to maintain shared objects consistently inside of SOM and to reduce the overhead of network traffic. The central part is a virtual node which corresponds to the Object Controller of SOMwith the SOT(Shared Objet Table).

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.12a
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• pp.301-313
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• 1999

Recently, the rabid development of information technology has brought enormous changes in education. Consolidation of communications and multimedia technologies are enabling the new educational paradigm such as distance learning and virtual education. Furthermore, many studies in the education engineering field report that teaching using multimedia technologies more enhances students' performance than the traditional instructor-teaching method. However, little research regarding the education using multimedia has been done in the MIS filed. None of multimedia-related studies could be found in the top-ranked MIS journals published in Korea for the last five years, and only a few studies were found even worldwide. In this regard, the purpose of this study is to investigate which features of multimedia software are most important to enhance the teaching results of students. From the previous research, we found out the specific features of the educational multimedia software which are considered to affect the students'performance, and defined the research variables related to those educational software features. And, based on the constructivism and motivation theory of the education engineering field a theoretical research model and research hypotheses were developed. Perceived usefulness of the class and a student's perceived interests in the class were used as surrogate variables to measure teaching performance. Total 277 students participated separately in one of the two multimedia classes which have continued for three weeks. One was C programming language class and the other was multimedia CD-title development class. Each student listened for the multimedia session of the class using multimedia software and, at the end of the multimedia session, answered the survey questionnaire. The results of the study show that motivation to the class and the contents of education were statistically significant to the students'performance in the class. That implies, not only in the traditional instructor-teaching method but also in the multimedia class, that the contents of education itself and student's motivation to the class are most important to raise instructional results.

• Journal of Biosystems Engineering
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• v.5 no.2
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• pp.26-39
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• 1980

A study was investigated to find out the mechanical optimum conditions of power tiller-plow system on both paddy field and upland. Mathematical model was developed for the theoretical analysis of this system and the experimentation on the field was carried out with two different sizes of 5PS and 8PS power tiller equipped with rubber tire. 1) The relationship between the plowing depth and draft resistance of the power tiller-plow system was a quadratic function. 2) The minimum point of the specific draft resistance of the 5 PS plow was found at the smaller plowing depth than that of 8 PS plow, therefore we can find that the curved surface of 5PS plow bottom should be improved for the effective plowing operation. 3) As the improvement of the mechanical balance by the desirable change of the curved surface of plow bottom, the relative position of hitch point and dimension of plow beam would be realized, the 5 PS power tiller could be used to plow deeply (about 16-17cm). 4) The virtual acting point of the total draft resistance on the plow bottom approached to the land side as the plowing depth increased. 5) The resultant of vertical reaction force $R_2$ on the landside was increased with the plowing depth, while the vertical reaction force $R_1$ on the wheel was decreased as the slope angle of the body of power tiller increased. 6) For the effective plowing operations ; a) The slope angle of the body should be as small as possible. b) The diameter of the wheel should be as small possible. c) The horizontal and vertical distances $l_2, h_1$ between the wheel axis and plow bottom should be as large as possible. 7) To use the 5PS power tiller as the major unit of agricultural machinery, the curved surface of the 5 PS plower bottom and the mechanism of attachment between the power tiller and the plow should be changed as the indications of this study, and in addition to these, the new operation method of the field work should be developed.

• Journal of Korea Multimedia Society
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• v.10 no.12
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• pp.1566-1576
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• 2007

Camera pose information from 2D face image is very important for making virtual 3D face model synchronize with the real face. It is also very important for any other uses such as: human computer interface, 3D object estimation, automatic camera control etc. In this paper, we have presented a camera position determination algorithm from a single 2D face image using the relationship between mouth position information and face region boundary information. Our algorithm first corrects the color bias by a lighting compensation algorithm, then we nonlinearly transformed the image into $YC_bC_r$ color space and use the visible chrominance feature of face in this color space to detect human face region. And then for face candidate, use the nearly reversed relationship information between $C_b\;and\;C_r$ cluster of face feature to detect mouth position. And then we use the geometrical relationship between mouth position information and face region boundary information to determine rotation angles in both x-axis and y-axis of camera position and use the relationship between face region size information and Camera-Face distance information to determine the camera-face distance. Experimental results demonstrate the validity of our algorithm and the correct determination rate is accredited for applying it into practice.

• Journal of KIISE:Information Networking
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• v.30 no.2
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• pp.270-281
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• 2003

ETF made the RFCs of MPLS technologies for providing the QoS of ATM or Frame Relay and the flexibility&scalability of IP on the Internet services. IETF has been expanding MPLS technologies as a common control component for supporting the various switching technologies called GMPLS. Also, IETF has standardized the signaling protocols based on such technologies, such as LDP, CR-LDP and RSVP-TE. ETRI developed the MPLS system based on ATM switch in order to provide more reliable services, differentiated services and value-added services like the VPN and traffic engineering service on the Korea Public Sector network. We are planning on deploying model services and commercial services on that network. This paper explains the basic functions of LDP, design and development of LDP on our system, and compares with LDP development and operation on other MPLS systems made by Cisco, Juniper, Nortel and Riverstone. In conclusion, this paper deduces the future services and applications by LDP through these explanation and comparison.

• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.39-47
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• 2013

Top Drive Machine is drilling equipment which transfers motor torque to the drill bit. Kelly Rotary Table of the Derrick Drilling Machine (DDM) is firstly developed at 1983, and the first commercial model DDM 650DC was released at 1984. Offshore drilling business is high value-added industries. "N" Company of U.S.A and "A" company of Norway hold more than 90 percent of the global offshore drill system market, so it is hard to take away market share and develop offshore drilling equipment. Consequently, this paper introduce method for concept design of new reliability machine by limited information. To achieve this, design & analysis tools as CATIA, DELMIA, Pro Engineering, ANSYS were used to evaluate design error and strength/flow analysis at new concept design in Top Drive Machine.

• Journal of Korean Society of Transportation
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• v.30 no.4
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• pp.7-19
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• 2012

In this study of estimating the benefits of environmental materials, the CVM method used in environmental economics was applied to estimate the value of pedestrian environment improvement. After finding the Willingness To Pay (WTP) level of residents through CVM, this study attempts to calculate quantitative benefits from the pedestrian environment improvement. In this study, a survey targeting the inhabitants in Seongbuk-gu adjacent to a business area was carried out for pedestrian environment improvement considering form of payment, willingness to pay and such by establishing and showing several virtual scenarios depicting a quiet and comfortable pedestrian environment. As a result, the willingness to pay level of the Seongbuk-gu residents was 627 won of surcharge for pedestrian environment improvement per month. Additionally, the annual total benefits by pedestrian environment improvement was estimated within a range from 1,247,516,820 won to 286,305,110 won.