• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.99-110
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• 2009

This study is to establish urban green network on the urbanized area using characteristics of fragmented and ornamental green area distribution. To do this, the survey for the green area characteristics was carried out in Changwon City. In order to analyze network, a virtual network in whole city sky for bird's movement, which is consisted with 30m grid lines was prepared. To analyze which network routes depend on the direction, we estimated bird's movement between 8-direction and 16-direction's outskirt forest's source point and inner city's fragmented green area. In the analysis of two types different direction models, the results of green network routes are mostly matched. So green network plan by this results is more reasonable for enhancing bird's movement to inner city. Based on the these findings, this green network planning will be providing for inner city to influx outside forest's birds and maximize the ecological connectivity.

• Archives of design research
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• v.16 no.2
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• pp.345-354
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• 2003

Digital TV broadcasting technology is recognized as a very encouraging technological development by koreans because of high-definition, multi-channel and interactive services which would broaden the viewers choice and promote people's prosperity. The technological development of digital TV service is a drastic change for people's convenience and would be a major media of‘e-government’in Korea. Digital TV Program UI will affect to people's esthetic sense and information efficiency. The information search pattern in TV is different from it of computer which has lead interactive media so far This research verifies the reasonable information display method through the usability test based on former related researches. For the case study, Interactive EPG design of SkyLife is selected and reviewed. This research includes the design development of interactive EPG of DVB-MHP.

• Journal of Broadcast Engineering
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• v.15 no.6
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• pp.803-814
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• 2010

In this paper, we propose a frame structure for modified ATSC transmission systems which is used for a terrestrial 3D HDTV broadcasting. The modified ATSC transmission systems [2] see the potential of increasing a transmission capacity at reasonable TOV (Threshold of Visibility) by modifying channel codes of conventional ATSC systems and varying modulations. We use PN symbols (Pseudorandom Noise) in a guard interval which is used for avoiding the ISI (Inter Symbol Interference) to estimate and compensate the time-varying multi path channel effectively with a maximum transmission payload. With PN symbols in the guard interval, a CIR (Channel Impulse Response) in a time domain can be estimated and a compensation in a frequency domain can be achieved for the accurate channel estimation and compensation. The prosed frame structure is applied to the modified ATSC systems and computer simulations are performed for SER (Symbol Error Rate) performances in TU (Typical Urban)-6 Channel.

• KCID journal
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• v.18 no.2
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• pp.87-100
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• 2011

This study is to delineate the watershed hydrological parameters such as area, slope, rain gauge weight, NRCS-CN and time of concentration (Tc) by using the Geographic Information Sytem (GIS) technique, and estimation of design flood for an ungauged watershed. Especially, we attempted to determine the Tc of ungauged watershed and develop simple program using the cell-based algorithm to calculates upstream or downstream flow time along a flow path for each cell. For a $19km^2$ watershed of tributary of Nakdong river (Seupmoon), the parameters including flow direction, flow accumulation, watershed boundary, stream network and Tc map were extracted from 30m Agreeburn DEM (Digital Elevation Model) and landcover map. And NRCS-CN was extracted from 30m landcover map and soil map. Design rainfall estimation for two rainfall gauge which are Sunsan and Jangcheon using FARD2006 that developed by National Institute for Disaster Prevention (NIDP). Using the parameters as input data of HEC-l model, the design flood was estimated by applying Clark unit hydrograph method. The results showed that the design flood of 50 year frequency of this study was $8m^3/sec$ less than that of the previous fundamental plan in 1994. The value difference came from the different application of watershed parameter, different rainfall distribution (Huff quartile vs. Mononobe) and critical durations. We could infer that the GIS-based parameter preparation is more reasonable than the previous hand-made extraction of watershed parameters.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1183-1188
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• 2005

In this paper, we propose a 3D automated measuring system which measures the mandibular movements and the reference plane of the jaw movements. In diagnosis and treatment of the malocclusions, it is necessary to estimate the mandibular movements and the reference plane of the jaw movements. The proposed system is configured with double stereo-cameras, PC, two moving pattern plates(MPPs), two fixed pattern plates(FPPs) and one orbital marker. The virtual pattern plate is applied to calculate the homogeneous transformation matrices which describe the coordinates systems of the FPP and MPP with respect to the world coordinates system. To estimate the parameters of the hinge axis, the Euler's theorem is applied. The hinge axis points are intersections between the FPPs and the hinge axis. The coordinates of a hinge axis point with respect to the MPP coordinates system are set up to fixed value. And then, the paths of the jaw movement can be calculated by applying the homogeneous transformation matrix to fixed hinge axis point. To examine the accuracy of the measurements, experiments of measuring the hinge axis points and floating paths of them are performed using the jaw motion simulator. As results, the measurement errors of the hinge axis points are within reasonable boundary, and the floating paths are very similar to the simulator's moving path.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.6
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• pp.909-914
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• 2011

In these days, according to the enhancement of the mobile communication technologies, location based services using the location and movements are vitalized. In this paper, we develop a private vehicle tracking system for garbage truck operation management using GPS and CDMA communication and Open map interface. The terminal equipment attached in vehicle receives the GPS signals and detect the position data including time, longitude, latitude, and altitude. And the terminal sends these data to the server PC through CDMA cellular network in fixed period. The server saves these data into database to process in map server program with which we can view real-time trace of moving vehicle. We apply our system to public garbage truck managing operation and we can increase operation efficiency by examine real-time working and moving path and by present reasonable operation rout.

• Journal of Environmental Science International
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• v.29 no.2
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• pp.133-144
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• 2020

The national parks of South Korea take up an area of 6,726 ㎢, which accounts for 6.7% of the national land. They are national conservation areas with their area made up of 59.1% of land (3,972.6 ㎢) and 40.9% of seawaters (2,753.7 ㎢). And in 2019, the national parks are classified by type into 17 mountainous, 4 maritime or coastal, and 1 historical site. Here, the maritime or coastal nation parks are lately spotlighted as landmarks in maritime tourism. However, the area of the maritime or coastal national parks is continuously dwindling due to conflicts between the residents in the parks and Korea national park service, the continued pressure with respect to the regional tourism development and private investments, and the abolition of parks in relation to allegedly breached private properties. This study identifies the issues with the operation and management of national parks as caused by the abolition of parks and the reduction of areas, and goes from there to do research with the aim of suggesting an institutionalized improvement plan with a view to more useful operation and management of the maritime or coastal national parks. As a result, the natural resources in the sea and on land should be surveyed again to establish the standard for use-specific zoning and reorganize the park areas in adjusting the national park areas. Second, the use-specific districts need to be reviewed for their reorganization that meets the designation requirements by focusing on the characteristics of the different national parks with a view to ensuring reasonable natural conservation in the maritime or coastal national parks. Third, various support facilities for residents such as public path, lodgings, and rentals need to be created to reduce the conflicts between Korea national park service and those who live in the parks.

• Architectural research
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• v.13 no.3
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• pp.31-40
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• 2011

Profit-keeping behaviors naturally occur in the market to satisfy consumers, and the logic behind it lies in the economies of scale. On the flip side, some commodities transacted in the market are not available or can not be easily acquired unless the demand is high enough. Under this proposition, some consumers rise and find their own solution to meet the services at a reasonable cost or at an adequate level. The commonly adopted way is to establish a cooperative, and it stirs purchasing power by pooling resources and further bargains price and service quality. As a consumer cooperative, housing cooperatives notably found in rural towns enable the elderly to continue independent living. This study is to take a closer look at residential life of the rural elderly in housing cooperatives. Utilizing in-depth focus group interviews with 40 residents in four housing cooperatives, this qualitative research draws main factors affecting the decision to move in, residential assessment, and strengths and weakness of living in a housing cooperative. The primary factor influencing the moving decision is to continue to independent living in a familiar community, and the bottom line is planning ahead. Frailty and bereavement are found to be the leading occasions for them to move. The participants are satisfied with the independent living arrangement, and particularly, cited such features as safety and security, elderly-friendly design, common spaces, freedom, social activities and efficient living. Also, it is stated that some cooperative natures such as control over the property and giving a voice on management render positive impacts on the satisfaction with communal living. In spite of all the benefits and strengths, participants face with a public notion that an independent living arrangement like a housing cooperative has never done before in rural towns, so that most people recognize it as part of dependent living arrangements like nursing home.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.9 s.180
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• pp.2159-2166
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• 2000

Recently, high performance machining center requires special type of sealing mechanism that prevent a leakage of oil jet or oil mist lubrication system. Sealing of oil-air mixture plays important r oles to have an enhanced lubrication for performance machining center. Current work emphasizes on investigations of the air jet effect on the protective collar type labyrinth seal. To improve sealing capabilities of conventional labyrinth seals, air jet is injected against the leakage flow. In this study, an adapted model is introduced to improve sealing capability of conventional non-contact type seals. It has a combined geometry of a protective collar type and an air jet type. Both of a numerical analysis by CFD (Computational Fluid Dynamics) and experimental measurements are carried out to verify sealing improvement. The sealing effects of the leakage clearance and the air jet magnitude aic studied in various parameters. Gas or liquid has been used as a working fluid for most of nori-contact types seals including the labyrinth seal. However, it is more reasonable to regard two-phase flows because oil mist or oil jet are used for high performance spindle's lubrication. In this study, working fluid is regarded as two phases that are mixed flow of oil and air phase. Both of turbulence and compressible flow model are also introduced in a CFD analysis to represent an isentropic process. Estimation of non-leaking property is determined by amount of pressure drop in the leakage path. Results of pressure drop in the experiment match reasonably to those of the simulation by introducing a flow coefficient. Effect of the sealing improvement is explained as decreasing of leakage clearance by air jetting. Thus, sealing effect is improved by amount of air jetting even though clearance becomes larger

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.5
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• pp.100-109
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• 2003

A performacne simulation model of the PT6A-62 turboprop engine using the $SIMULINK^R$ was proposed to predict transient and steady state behaviors. The $SIMULINK^R$ has several advantages such as user-friendliness due to the GUI(Graphic User Interfaces) and ease in the modification of the computer program. The $SIMULINK^R$ model consists of subsystems to represent engine gas path components such as flight initial subsystem, compressor subsystem, burner subsystem, compressor turbine subsystem, power turbine, exhaust nozzle subsystem and integrator subsystem. In addition to subsystems, there are search subsystems to find an appropriate operating point by scaling from the 2-D components look-up table, Gasprop Subsystem to calculate the gas property precisely. In case of steady state validation, performance results analyzed by the proposed $SIMULINK^R$ model were agreed well with the analysis results by the commercial GASTURB program. Moreover in validation of the transient model, it was found that performance simulation results by the proposed model were reasonable agreement with analysis results by the well-proved computer program using FORTRAN.