• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.8
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• pp.72-81
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• 2004

A Wind tunnel test for a high speed ground vehicle was conducted to investigate the aerodynamic interactions between the vehicle and a solid channel. The free stream velocity was 30m/see and Reynolds number per unit length was $3.1{\times}10^5/m$. Experimental devices such as a variable channel ground and guide way were used for the test. As the vehicle was close to the channel ground and guide way, lift was significantly increased, drag was slightly decreased and pitching moments were restricted to augment static stability. Using smoke-wire, flow visualization was made to confirm these results by comparing the channel and non-channel flow characteristics of the vehicle. Under the influence of the channel ground and guide way, the flow beneath the vehicle was not discharged outside wing end plates, which was the major reason of the increase in lift of the vehicle.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.185-194
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• 2014

This study investigates the methodology to evaluate the quantified performance of pavement markings and traffic guide signs using digital images. This methodology is significant to attempt to quantify their performance without large brightness photometer at the nighttime and bad weather. The retroreflective performance of pavement markings are evaluated through the contrast of gray levels of pavements and markings in collected digital images under the case of rain, dampness, and dryness. In addition, the appraisal of retroreflective performance of traffic guide signs are implemented through the comparison between interior illuminated and the existing retroreflective traffic guide signs using the contrast of luminance extracted from the value of RGB of backgrounds and legends in collected digital images according to geometric design, driving lanes, and the distance between the car and the sign. As a result, the retroreflective performance of pavement markings deteriorates about 3.5 times and 2 times under the case of rain and dampness respectively than dryness. Also, the performance of the existing traffic guide signs is significantly influenced by geometric design, driving lanes, and the distance, otherwise interior illuminated traffic guide signs. This methodology can be utilized to construct objective information of performance of traffic safety facilities to select appropriate position of expensive high reflective pavement markings and interior illuminated traffic guide signs considering diverse weather and geometric design.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.894-898
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• 2007

지하방수로는 도시의 지하에 대규모 수로 터널을 시공하여, 도시 지역에 발생한 집중 호우를 초기에 배제하여 제내지 침수 피해를 줄이는 목적으로 사용되는 대표적인 구조적 홍수 피해 경감 대책이다. 효과적으로 침수피해를 줄일 수 있을 뿐만 아니라, 특히 지하에 설치되어 토지 수용에 대한 부담이 줄어들기 때문에 일본 등지에서 최근 주요 홍수 방어 대책으로 활용되고 있다. 지하방수로 유입부는 크게 접근수로, 유입구, 수직 갱도(vertical shaft)로 구분되며, 접근 수로를 통하여 유입된 흐름은 유입구를 통하여 가속된 후 수직 갱도로 유입되게 된다. 따라서 지하방수로의 배제 능력을 평가하기위해서는 유입구에서의 유량 및 흐름 특성을 정확히 평가하는 것이 매우 중요하다. 나선식 유입구(spiral intake)는 지하방수로 유입구 중 가장 일반적으로 사용되는 형식으로 일반적으로 접근수로 수위를 측정하여 유입량을 예측할 수 있다. 본 연구에서는 수리 모형 실험을 통하여 나선식 유입구에 대한 수위-유입량 관계를 검토하였다. 평탄한 입구를 가지는 안내벽이 있는 형식의 나선식 유입구 모형을 이용하여 수위-유입량 관계를 검토하였다. 또한 측정된 수위 및 유입량을 바탕으로 기존 연구자들이 제시한 안내벽이 없는 형식의 나선식 유입구에 대한 수위-유입량 관계와 비교 검토하였다. 검토 결과 안내벽이 있는 형식의 나선식 유입구는 안내벽이 없는 경우에 비하여 유량 배제 효율이 떨어지는 것으로 나타났다.

• Journal of Aerospace System Engineering
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• v.10 no.4
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• pp.11-16
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• 2016

In this paper, an experimental study on the aerodynamic characteristics of a variable span wing flying inside a channel guideway is accomplished using wind tunnel testing. A variable span wing with a NACA 0012 airfoil section was fabricated and actuated using a linear servo motor. The aerodynamic effects of 1) wing aspect ratio, 2) ground effect, and 3) the gap between the wingtip and the wing fence were investigated. It was found that both ground effect and wing fence gap increased lift. Also, the wing fence gap does not significantly affect drag. Therefore, it was found that a variable span mechanism can be used as an effective high lift device when flap use is limited.

• The Journal of the Acoustical Society of Korea
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• v.15 no.6
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• pp.110-116
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• 1996

In this paper a novel method improving the accuracy of DTMF tone reception in ARS system is proposed. ARS system should allow users to generate DTMF signals while it is sending voice guidance. It is not unocmmon, in this case, that a portion of transmitting voice signals cross-talks to the receiving channel and it often results in interfering with the receiving DTMF signals. Serious degradations including DTMF tone missing, false alarm and so forth have been introduced for the above reason. To overcome this phenomena, we have proposed a way eliminating the frequency spectra representing DTMF signals bands from the transmitting voice signal by using notch filters. This method also employs bandpass filters of which the frequency responses are reciprocal to those of the notch filters incorporated with the DTMF receiver. It is shown that a drastic improvement has been achieved with respect to the DTMF tone detection with little deterioration of voice guidance quality.

• Korean Journal of Environment and Ecology
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• v.10 no.1
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• pp.14-23
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• 1996

Visitors to Naejangsan National Park were surveyed from October 31 to November 3 in 1995, 151 visitors were participated. Of those individuals, 55% were males. 48% of respondests reported that they had gone beyond high school, and over one-half(52%) had gone as far as college. 61.3% were 20 years of age. The largest percentage of respondents were reported that they visited Naejangsan Nat'l Park to see the scarlet maple leaces there. Most respondents who witness other visitors' littering were not likely to intervene to stop their visitors' depreciative behavior(Bystander intervention Begavior). Most of visitors got information for use Naejangsan Nat'l Park from a guide sign(31.8%) or guide themselves(29.1%). They didn't know the Clean-up Time Movement Program. But they understood it after notice hanging placards(81.6%). Most of visitors responded that didn't hear the mass communication program in National. But they recognized necessity of the mass communication program in National Park. The results showed that most visitors believed that Clean-up Time Movement was in succession consequently it turned out to be effective in managing visitors' littering behavior. And it seemed to effective in managing depreciative behavior through the mass communication program in National Park.

• Korean Journal of Environment and Ecology
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• v.20 no.3
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• pp.319-330
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• 2006

It is imperative that pictograms as pictorial information be empirically tested in order to establish whether the users do indeed associate the appropriate referent in an actual usage situation. The experiment employing the Multiple Index Approach was conducted in a class room with 64 subjects to evaluate tourism and recreation related pictograms. Performance data(hit rate, false alarm and missing value) of 25 pictograms were collected and the average hit rate as a prime index of pictogram associativeness was 65.82%. The matrix analysis showed 14 pictograms were high in subjective certainty and subjective suitability. The other 11, which were low in both criteria may require prior learning or improvement of the pictogram designs to represent their meanings more distinctively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.1
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• pp.47-57
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• 2002

The intention of this study is to construct the spatial database and to extract attribute data which are able to complete the omitted data in the topographical map or completion map of construction using the image data of various form such as artificial satellite images, aerial photographs, terrestrial photographs and so on. This study used the single frame images only for the raw image data, supposing the case of rigorous photogrammetric method is not available or rapid acquisition of information is need. The extracted spatial and attribute data from the images are used for modifying and updating the database, and for providing visual effect useful for guide and management of the facilities. This study intended to develop the technique able to apply in the case where comparative high accuracy is not required or rapid modification is necessary, and to verify the possibility of editing and updating the digital map using the photographs or video images remained as old data. Many of previous research on the management system for university facility has been accomplished focusing on the design and construction of database itself. Otherwise, this study aimed for the construction of guide and management system based on compiling the digital map of present state using multi-imagery, and the more applicability was intended too.

• Journal of the Korean association of regional geographers
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• v.13 no.3
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• pp.355-375
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• 2007

This study explores the geographic characteristics of ecotour resources in Oceania based on the concept of ecotourism along with global education and investigates the global educational applications of eco-resources through a field survey of the Australian Cairns region. The field survey areas are the Green Island within the Great Barrier Reef, Barron Gorge National Park, the Australian Butterfly Sanctuary in Cairns, and the Tjabukai Aboriginal Cultural Park. This case study of the Cairns region is applicable to global education in these aspects: The underwater Observatory and Glass bottom boat in Green Island is used in efficient exploration of ocean ecology; Barron Gorge National Park provides an excellent forest tour with a well-made track, detailed directory, and trained park rangers; the old industrial trains are being recycled for tourism uses; the Australian Butterfly Sanctuary provides various language interpretations and experts to help further visitor's understanding of the surrounding eco-resources; The Aboriginal Cultural Park also utilizes a special program that helps people understand their culture.

• 한국항공운항학회:학술대회논문집
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• 2015.11a
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• pp.183-185
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• 2015

A-SMGCS는 외부로부터 비행계획정보, 레이더 정보 및 기상정보를 수신하여 경로, 안내, 감시 및 항공등화 제어 기능을 수행하는데, 이러한 기능을 검정하기 위한 시뮬레이터는 기초자료 준비, 기상 시나리오 생성, 이벤트 시나리오 생성 및 항적자료 생성 등의 4가지 기능으로 구성되어 가상의 정보를 자동으로 생성하게 된다. 생성된 정보는 A-SMGCS에서 수신하여 그 정보를 바탕으로 각각의 기능들을 실행하게 되고, 그 실행 상태는 A-SMGCS HMI에 모니터링 된다. 그러므로 시뮬레이터에서 생성되는 가상의 시나리오들은 실제 공항에서 발생하거나 예측되는 모든 경우의 상황을 A-SMGCS에 제공하여 정확한 검정을 할 수 있도록 지원함으로써 A-SMGCS의 성능을 한층 더 향상시킬 수 있을 것이다. 따라서 본 논문에서는 이러한 효과가 기대되는 시뮬레이터의 기능과 연동관계를 정리하여 최적의 시뮬레이터를 제작할 수 있는 방법에 대한 연구를 실시하였다.