• Journal of Korean Society for Geospatial Information Science
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• v.10 no.2 s.20
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• pp.39-47
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• 2002

For the purpose of data construction for the systematic management and sight-seeing guidance of the natural park, the Kumoh Mt. Province Park was selected as a pilot area. Digital topographic maps, thematic maps and satellite imagery covering the object area were processed and then landform analysis for elevation, slope, aspect and so on was conducted through DEM generation, and the landcover map and NDVI maP were extracted from Landsat TM data. The database was then constructed with these spatial data for GSIS. The image map was generated from IKONOS satellite data, which cover the pilot area data, with one meter resolution and also 3D visualization which was overlaid with main paths up a mountain were conducted. And the moving image files were produced along main paths up including main natural spectacular sights, cultural assets and management facilities. It is expected that the research result can be utilized as the fundamental data for re-assessing suitable land use and constructing Web-based guidance system.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.105-115
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• 2015

PURPOSES : This study aimed to evaluate the appropriateness of safety with the standard for threshold zone luminance as specified in the Recommendation for Lighting of Traffic Tunnel, which has been widely adopted worldwide. METHODS : A driving test of the subject in a full-scale road tunnel was conducted. The adaptation luminance and threshold zone luminance, which should be known for the driver to perceive an object within stopping sight distance, were obtained. These values were compared with the adaptation luminance and threshold zone luminance obtained by the existing reduced model test and tunnel lighting standard that has served as a guideline for the current threshold zone luminance standard. RESULTS : According to this study, threshold zone luminance should be increased to at least 1.8 times the value proposed in the existing studies and to twice the domestic tunnel lighting standard (KS C 3703: 2014). CONCLUSIONS : The threshold zone luminance proposed in this study differs largely from that obtained from indoor tests and from the current tunnel lighting standard used worldwide; this difference may be attributed to the fact that the indoor tests did not incorporate driving workload, non-uniformity of luminance distribution in terms of sight, and factors that reduce the visibility of the driver, such as the light reflected into the driver's eyes. Hence, it is necessary to further review the factors that reduce the visibility of drivers approaching tunnels in order to determine the rational tunnel threshold zone luminance.

• The Journal of Society for e-Business Studies
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• v.17 no.3
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• pp.1-14
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• 2012

As the techniques of electronic and information are advancing, the computing power of a smart phone is becoming more powerful and the storage capacity of a smart phone is becoming larger. As the result, various new useful services are becoming available on smart phones. The context-aware service and mobile augmented reality have recently been the most popular research topics. For those newly developed services, identifying the object in the picture taken by the camera on the phone performs an extremely important role. So, many researches of identifying pictures have been published and most of them are based on the time consuming image recognition techniques. On the contrary, this paper introduces a very fast and effective method of identifying the objects on the photo making use of the sensor data obtained from the smart phone and electronic maps. Our method estimates the line of sight of the camera with the location and orientation information provided by the smart phone. Then it finds any element of the map which intersects the line of sight. By investigating those intersecting elements, our method identifies the objects on the photo.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.303-307
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• 2009

Secondary flow losses can be as high as $30{\sim}50%$ of the total aerodynamic losses generated in the cascade of a turbine. Therefore, these are important part for improving a turbine efficiency. As well, many studies have been performed to decrease the secondary flow losses. The present study deals with the leading edge fences on a wing-body to decrease a horseshoe vortex, one of the factors to generate the secondary flow losses, and optimizes the shape of leading-edge fence with the shape factors, such as the installed height, length, width, and thickness of the fence as the design variables. The study was investigated using $FLUENT^{TM}$ and $iSIGHT^{TM}$. Total pressure loss coefficient was improved about 7.5 % than the baseline case.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.5
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• pp.355-365
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• 2017

In this paper, we propose the design of a dual-band GPS antenna using in-direct feeding pads. The antenna consists of an upper patch for the GPS L1 band, a lower patch for the GPS L2 band, and two pads on the middle layer for feeding the two radiating patches. A hybrid chip coupler with a phase difference of $90^{\circ}$ is employed at the two feeding ports for achieving a broad circular polarization (CP) bandwidth. The proposed antenna shows bore-sight gains of 3.0 dBic(L1) and 5.1 dBic(L2), and axial ratios of 3.3 dB(L1) and 0.3 dB(L2) by measurement. The active element patterns of the fabricated array with 7 elements show bore-sight gains of -0.4 dBic (L1) and -2.4 dBic(L2), respectively. It proves that the proposed antenna structure is suitable for use in GPS array applications.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.4 s.111
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• pp.22-32
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• 2005

The purpose of this study is to analyze characteristics of prospect from the mountain pass by investigating relations between the type of mountain pass and object overlooked from the mountain pass. For the purpose, this researcher selected and surveyed 44 mountain passes located in Busan, except in Gangseo-gu lesion. According to their locational characteristics, the mountain passes were classified into three types, 'sanmok'(formed between mountain peaks), 'sanheori'(formed on the mountainside) and 'sanmaru'(formed at the tip of the mountain peak). Out of the total 44 mountain passes, 22 were 'sanheori' in type. In the same type, mountain passes mostly had a prospect providing the overlap of downtown and mountain areas. The researcher examined the sight distance and dip of object to be viewed from the mountain pass, determining relations between the object and the mountain pass. When overlooked from mountain passes in Busan, most objects are distributed between $-3^{\circ}\;and\;-1^{\circ}$ in an angle of depression within the sight distance from 0.5km to 14km. Mountain passes are valuable as a post that is very important in prospecting scenes. But they are now in crisis. They are being gradually disappeared because of development projects. Finally, the researcher hopes that the study makes recognizing the value of the mountain pass and contributes to preserve the mountain pass as an important post of view point when its region is later developed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1789-1798
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• 2012

IEEE 802.15.4a standard can provide a variety of location-based services for ZigBee or wireless network applications by adapting the time-of-arrival (TOA) ranging technique. The non-line-of-sight (NLOS) condition is the critical problem in the IEEE 802.15.4a networks, and it can significantly degrade the performance of the TOA-based localization. To enhance the location accuracy due to the NLOS problem, this paper proposes an energy-efficient low complexity localization algorithm. The proposed approach performs the ranging with the multicast method, which can reduce the message overhead due to packet exchanges. By limiting the search region for the location of the node, the proposed approach can enhance the location accuracy. Experimental results show that the proposed algorithm outperforms previous algorithms in terms of the energy consumption and the localization accuracy.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.11
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• pp.2541-2546
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• 2013

In this paper, we proposed on the azimuth correction method for a line-of-sight data-link tracking antenna system. Tracking antenna system is essential to maintain line-of-sight between moving object and data-link equipment. In order to calculate the azimuth and elevation between the moving object and antenna system, we used GPS data. also to match the each coordinate systems, we used geomagnetic sensor or beacon. However, the geomagnetic disturbance-prone terrain in places difficult to correct calibration. The first step, finds the location of the strongest RF signal, we should remember the difference between the reference point and the detected position of the antenna. The second step, we could communicate each other. And the azimuth angle is calculated by GPS values. Despite the geomagnetic interference, we can correct the azimuth angle quickly and easily.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4A
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• pp.224-231
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• 2003

In this in this thesis, we have proposed the Kor-231 which compared with Hata by dividing 4 classes and 8 details, which based on that the area subdivision which is defined by the City planning Regulation of Korea classified on its rate of building-to-land, floor area and distance between buliding and botanical coefficient. The experiments are carried out at the point of the RMS delay spread and the recerived power in the two kinds of geographical areas, LOS(Line of Sight) and N-LOS(Non Line of Sight). When the measured result is compared with Kor-231 model, we can catch the result that received power are 25.5dB and 14.5dB, the RMS delay spread are 101ns and 35ns and N-LOS received power are 4.1dB and 1.6dB. So we have certified that it is well due to the result analyzed into the difference of the RMS delay spread from 74ns to 200ns.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.2A
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• pp.119-127
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• 2012

In this paper a super-resolution time delay estimation algorithm is developed for real-time locating systems (RTLSs) that employ a direct-sequence spread spectrum technique, along with its performance analysis in multipath environments. The classical correlation method provides relatively good performance in line-of-sight (LOS) environments but its performance seriously degrades in multipath environments, especially when signals are spaced closer than a PN chip. Therefore we shall develop a super-resolution time delay estimation algorithm that may estimate the time delays of multipath signals even in closely spaced multipath environments using the MUSIC algorithm for direction-of-arrival estimation and analyze its performance by applying the algorithm to the ISO/IEC 24730-2.1 RTLS system.