• Ocean and Polar Research
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• v.35 no.1
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• pp.1-14
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• 2013

Shoreline data of the barrier islands in Nakdong River Estuary for the last three decades were assembled using six sets of aerial photographs and seven sets of satellite images. Canny Algorithm was applied to untreated data in order to obtain a wet-dry boundary as a proxy shoreline. Digital Shoreline Analysis System (DSAS 4.0) was used to estimate the rate of shoreline changes in terms of five statistical variables; SCE (Shoreline Change Envelope), NSM (Net Shoreline Movement), EPR(End Point Rate), LRR (Linear Regression Rate), and LMS (Least Median of Squares). The shoreline in Jinwoodo varied differently from one place to another during the last three decades; the west tail has advanced (i.e., seaward or southward), the west part has regressed, the south part has advanced, and the east part has regressed. After the 2000s, the rate of shoreline changes (-2.5~6.7 m/yr) increased and the east advanced. The shoreline in Shinjado shows a counterclockwise movement; the west part has advanced, but the east part has retreated. Since Shinjado was built in its present form, the west part became stable, but the east part has regressed faster. The rate of shoreline changes (-16.0~12.0 m/yr) in Shinjado is greater than that of Jinwoodo. The shoreline in Doyodeung has advanced at a rate of 31.5 m/yr. Since Doyodeung was built in its present form, the south part has regressed at the rate of -18.2 m/yr, but the east and west parts have advanced at the rate of 13.5~14.3 m/yr. Based on Digital Shoreline Analysis, shoreline changes in the barrier islands in the Nakdong River Estuary have varied both temporally and spatially, although the exact reason for the shoreline changes requires more investigation.

• Journal of Advanced Navigation Technology
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• v.3 no.2
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• pp.108-119
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• 1999

In recent, there has been remarkable progress in the field of GPS applications. In a few years, an appreciable number of aircraft will adopt GPS as a landing guidance system because GPS is more economic, more reliable and more accurate than any other aviation systems. In this respect, we have performed several helicopter landing flight tests based on the real-time DGPS system made in SNUGL (Seoul National University GPS Laboratory). From the experimental results, we found several problems Which should be fixed to adopt DGPS as a aircraft landing guidance system. In this paper, we will introduce the problems found in tests and also suggest modifications to solve the problems. Our modifications can be classified into three parts. The first is about the attitude determination with single GPS antenna. The second deals with the cockpit display module. The display was devised to integrate the Instrument Landing System(ILS) with tunnel-the-sky using virtual reality. With the display, pilot can achieve more safe landings. The last part is the digital map. We inserted digital map into our system and put direction indicator on the map using position information from GPS. It is very useful for pilot to find airports even in bad weather. Using the newly designed DGPS landing system, we conducted flight test at Kimhae International Airport, Pusan, Korea. It was successful! Our system can also satisfy Category-I criterion for aircraft landing approach and determine attitude angle with a high level of reliability. It is supported by video materials.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.685-691
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• 2007

In this paper through Honan high-speed railroad which is planned with the north and south axis, we will verify the feasibility of the coordinate conversion using railroad control points after regarding current planned-railroad as the linear central axises. From analysis, distortion of Y axis varies 21 cm to 40 cm diminishing to a gentle straight line, distortion of X axis varies 14 cm to 29 cm. Through a revision, the deviation value between the coordinates were 6 mm to 9 mm and it satisfied the allowable error of national geographic information institute which is following ITRF (International Terrestrial Reference Frame) and cadastral boundary survey (10 cm). consequently the coordinate conversion is possible using railroad control points as common control points.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.765-771
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• 2019

With the increase in the speed of ships and the size of ocean structures, the importance of flow noise has become increasingly critical in meeting regulatory standards. However, unlike active investigations in aeroacoustics fields for airplanes and trains, which are based on acoustic analogy methods for tonal and broadband frequency noise, only the discrete blade passing frequency noise from propellers is considered in marine fields. In this study, prediction methods for broadband noise in marine propellers and underwater appendages are investigated using FW-H Formulation1B, which can consider the mechanism of primary noise generation of trailing edge noise. The original FW-H Formulation 1B is based on the pressure correlation function tolackitsgeneralityandaccuracy. To overcome these limitations, wall-pressure spectrum models are adopted to improve the generality in fluid mediums. The comparison of the experimental results obtained in air reveals that the proposed model exhibits a higher accuracy within 5 dB. Furthermore, the prediction procedures for broadband noise for hydrofoils are established, and the estimation of broadband noise is conducted based on the results of the computational fluid dynamics.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2006.05a
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• pp.146-151
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• 2006

현재 국가지리정보유통망을 통해 유통되고 있는 수치지도(Digital map)는 대부분 항공 측량사진(Air survey Photographs)이나 위성영상(Satellite images)을 통해 취득된 토지 피복의 형상을 기반으로 제작된 지도들이다. 정사사진으로부터 취득된 지형정보를 기호화, 단순화한 수치지도는 실제 사물의 형태와 많은 차이가 있어 지형과 시설물의 변이를 사실대로 반영하지 못한다. 특히 최근 들어 지하시설물이나 건축기술의 발달로 층별 구조가 다양해진 건축물의 형태 등은 정사사진으로는 식별이 불가능하고 건물의 경우 지붕의 형태로 묘사되는 등 표현에 한계가 있다. 도심지역을 대상으로 제작된 1/1,000수치지형도나 일부 지자체나 공공기관 등에서 제작된 $1/500{\sim}1/2,500$ 수치지형도는 상세한 지형정보를 포함하고 있는 높은 정밀도의 수치지도이지만, 도시지역의 변이가 빠르게 일어나고 있기 때문에 자료 신뢰성과 최신성을 유지하는데 한계가 있다. 따라서 본 연구는 현지조사나 측량에 의존하고 있는 정사사진으로부터 취득이 불가능한 지형자료의 취득이나 수년단위인 갱신주기의 한계를 극복하고 실시간으로 수치지도를 수정갱신 할 수 있는 대안으로 일반측량성과도의 활용방안을 제시하고자 한다. 일반측량업에서 생산되는 일반측량성과도는 임시 도근점에 의해 측량을 실시하고 지적경계점과 현황기지점을 도해법에 의해 지적도와 중첩시켜 제작한 측량도로서, 일반측량 성과도에 절대좌표체계를 부여하고 수치지도와 매칭 기법을 제시함으로서 경제적이고 신속한 실시간 수치지도 수정갱신체계를 확립할 수 있고, 자료의 공유함으로써 중복측량을 방지할 수 있다.보 등)를 활용, 구축된다. 교통분석용 네트워크는 구축시점에 따라 현재 및 장래 네트워크로 구분되며 장래 네트워크는 기준년도부터 2031년까지 5년 단위로 계획된 장래도로를 반영하여 구축된다. 교통주제도 및 교통분석용 네트워크는 국가교통DB구축사업을 통해 구축된 자료로서 교통체계효율화법 제9조의4에 따라 공공기관이 교통정책 및 계획수립 등에 활용할 수 있도록 제공하고 있다. 건설교통부의 승인절차를 거쳐 제공하며 활용 후에는 갱신자료 및 활용결과를 통보하는 과정을 거치도록 되어있다. 교통주제도는 국가의 교통정책결정과 관련분야의 기초자료로서 다양하게 활용되고 있으며, 특히 ITS 노드/링크 기본지도로 활용되는 등 교통 분야의 중요한 지리정보로서 구축되고 있다..20{\pm}0.37L$, 72시간에 $1.33{\pm}0.33L$로 유의한 차이를 보였으므로(F=6.153, P=0.004), 술 후 폐환기능 회복에 효과가 있다. 4) 실험군과 대조군의 수술 후 노력성 폐활량은 수술 후 72시간에서 실험군이 $1.90{\pm}0.61L$, 대조군이 $1.51{\pm}0.38L$로 유의한 차이를 보였다(t=2.620, P=0.013). 5) 실험군과 대조군의 수술 후 일초 노력성 호기량은 수술 후 24시간에서 $1.33{\pm}0.56L,\;1.00{\ge}0.28L$로 유의한 차이를 보였고(t=2.530, P=0.017), 술 후 72시간에서 $1.72{\pm}0.65L,\;1.33{\pm}0.3L$로 유의한 차이를 보였다(t=2.540, P=0.016). 6) 대상자의

• Spatial Information Research
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• v.8 no.1
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• pp.141-153
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• 2000

The purpose of this study is to develop and apply spatial landslide information system using Geographic information system (GIS) in concerned with spatial data. Landslide locations detected from interpretation of aerial photo and field survey, and topographic , soil , forest , and geological maps of the study area, Yongin were collected and constructed into spatial database using GIS. As landslide occurrence factors, slope, aspect and curvature of topography were calculated from the topographic database. Texture, material, drainage and effective thickness of soil were extracted from the soil database, and type, age, diameter and density of wood were extracted from the forest database. Lithology was extracted from the geological database, and land use was classified from the Landsat TM satellite image. In addition, landslide damageable objects such as building, road, rail and other facility were extracted from the topographic database. Landslide susceptibility was analyzed using the landslide occurrence factors by probability, logistic regression and neural network methods. The spatial landslide information system was developed to retrieve the constructed GIS database and landslide susceptibility . The system was developed using Arc View script language(Avenue), and consisted of pull-down and icon menus for easy use. Also, the constructed database can be retrieved through Internet World Wide Web (WWW) using Internet GIS technology.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.3
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• pp.13-21
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• 2004

The dissemination of commercial satellite images. which have the high spatial resolution such as aerial photos, are the active trend in remote sensing community because of the recent development in satellite and sensor technology. Such high resolution satellite images provide a unique tool for the monitoring of ongoing urban land use change. Especially KOMPSAT-1, which was launched at December 1999 and successfully operated up to now, provides repeatedly panchromatic images over Korean peninsula, which has the spatial resolution of 6.6m. Based upon this KOMPSAT-1 EOC image data we can try to analyze and assess the temporal urban land use change, which could not be done because lack of such data. The aim of this paper is to analyze and assess the spatial land use characteristics of Daejeon Metropolitan City based on KOMPSAT-1 EOC data. The land use map of year 2001 is generated through the modification of the year 2000 land use map, which is published by National Geographic Information Institute, using visual interpretation of KOMPSAT-1 EOC image which is acquired in year 2001. This study can be the start point of the time series analysis of the long term land use change monitoring mit KOMPSAT-1 EOC data.

• International Commerce and Information Review
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• v.16 no.1
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• pp.207-226
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• 2014

A trade logistic informatization system under Open Systems Interconnection(OSI) includes a Port Management Information System, a Maritime Information System, and an Export and Import Batch Processing System. These have made a great contribution in the creation of more convenient and efficient management for the logistics industries in our country. However, this management is exposed to the technological problems of networks due to the explosive use in the sending and receiving of e-documents. For our country to grow as a center for port and logistic information, we should make the best use of the control systems using networks and further advance the export and import logistic systems. Therefore, this study aims to propose management systems for a composite network and an invasion detection system for efficient management of an e-trade network under OSI. Methods to rationalize the internal organizations such as coordination of organizations and human resources according to alloted network functions, commissions and arbitrary decisions, and reorganization of relevant regulations are not discussed here. This study looked at trade network under OSI from the aspect of practical business affairs and presented a basis for further interpretation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.8 s.111
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• pp.773-787
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• 2006

An airborne radar is an essential aviation electronic system for the aircraft to perform various civil and/or military missions in all weather environments. This paper presents the design, development, and test results of the multi-mode X-band pulsed Doppler radar system test model for helicopter-borne flight test. This radar system consists of 4 LRUs(Line-Replacement Unit), which include antenna unit, transmitter and receiver unit, radar signal & data processing unit and display Unit. The developed core technologies include the planar array antenna, TWTA transmitter, coherent I/Q detector, digital pulse compression, MTI, DSP based Doppler FFT filter, adaptive CFAR, moving clutter compensation, platform motion stabilizer, and tracking capability. The design performance of the developed radar system is verified through various ground fixed and moving vehicle test as well as helicopter-borne field tests including MTD(Moving Target Detector) capability for the Doppler compensation due to the moving platform motion.

• Journal of Advanced Navigation Technology
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• v.2 no.1
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• pp.61-67
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• 1998

In this paper, we have described the Ramp Activity Coordination Expert System (RACES) which can solve aircraft parking problems. RACES includes a knowledge-based scheduling problem which assigns every daily arriving and departing flight to the gates and remote spots with the domain specific knowledge and heuristics acquired from human experts. RACES processes complex scheduling problem such as dynamic inter-relations among the characteristics of remote spots/gates and aircraft with various other constraints, for example, custome and ground handling factors at an airport. By user-driven modeling for end users and knowledge-driven near optimal scheduling acquired from human experts, RACES can produce parking schedules of aircraft in about 20 seconds for about 400 daily flights, whereas it normally takes about 4 to 5 hours by human experts. Scheduling results in the form of Gantt charts produced by the RACES are also accepted by the domain experts. RACES is also designed to deal with the partial adjustment of the schedule when unexpected events occur. After daily scheduling is completed, the messages for aircraft changes and delay messages are reflected and updated into the schedule according to the knowledge of the domain experts. By analyzing the knowledge model of the domain expert, the reactive scheduling steps are effectively represented as rules and the scenarios of the Graphic User Interfaces (GUI) are designed. Since the modification of the aircraft dispositions such as aircraft changes and cancellations of flights are reflected to the current schedule, the modification should be notified to RACES from the mainframe for the reactive scheduling. The adjustments of the schedule are made semi-automatically by RACES since there are many irregularities in dealing with the partial rescheduling.