• 한국항공운항학회지
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• 제22권2호
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• pp.53-59
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• 2014

Simultaneous parallel approaches in all weather conditions should be applied to manage efficiently increasing volume of air traffic flow and solve the problem of delayed arrivals. But All of the airports which have closely-spaced parallel-runways in Korea don't meet the interval-standards for IFR parallel approaches. In that regard, more accurate and safer System should be applied for the Korean airports. GNSS was adopted as an international standard of the next-generation navigation system and many studies and master plans have been activated by stages in Korea. In this paper, the current state of the domestic airports will be analyzed focusing on the interval of parallel runways and future specification of both flight operation system and air-side management will be recommended.

• 한국도로학회논문집
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• 제15권4호
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• pp.167-175
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• 2013

PURPOSES : The objective of this study is to investigate the capability of the combined model of traffic simulation, emission and air dispersion models on the impact analysis of air quality of mobile sources such as vehicles. METHODS : The improvement of the quality of life brings about the increasing interest of the public environment. Many endeavors including the travel demand management, the application of the state-of-the-art ITS technologies, the promotion of eco-friendly vehicles have been tried in transportation area to reduce the modal emissions. Especially, it is expected that the increasing number of eco-friendly vehicles in the road network would be able to reduce the pipe-tail emissions tremendously. From this perspective, we have performed a study on the impact analysis of the popularization of the eco-friendly vehicle in the place of the fossil fuel energy powered vehicles on the surrounding air quality using the combined framework of microscopic traffic simulation, emission and air dispersion model. RESULTS : The combined model successfully captured the effect of moving to the eco-friendly vehicles on the air quality, and the results showed that the increasing usage of eco-friendly vehicles can improve the surrounding air quality tremendously and that the air dispersion model plays a crucial role in the investigation of the air quality change around the main corridor. CONCLUSIONS : This study demonstrated the capability of the combined model showing the spatio-tempral change of emission concentration.

• 아시안잔디학회지
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• 제21권2호
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• pp.127-135
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• 2007

Korea and Japan hosted the FIFA World Cup Soccer Game in 2002. Ten stadiums had been built and more than 30 soccer grounds for practice were renovated in Korea. Sport fields in both countries had problems on cool-season turfgrass growth and quality by summer decline during humid and warm climate especially followed by intensive uses. We measured the effects of air-flow system, which is designed to optimize rootzone soil gas and moisture levels to promote the growth and maintenance turfgrass. This experiment was carried out to verify the effects of the system on soil gas exchange, ground resilience, and turfgrass recovery in turfgrass rootzone. Within 1 or 2hr of operation of the system, rootzone soil gas ($CO_2$, $O_2$) levels returned to natural atmospheric levels completely Soil $CO_2$ levels began to decrease within the first 10 min of operation of the system. The levels were reduced from 1.3 to 0.06% after 30 min, and natural atmospheric levels within 1 hr. When the system was turned off, $CO_2$ levels increased to 0.36% and 0.7% after 5 and 20 hr, respectively. The application of the system did not affect the resilience of turf surface after traffic treatments. Higher traffic treatment resulted in higher surface resilience especially in zoysiagrass plots. Operation of the system had a significant beneficial impact on turf recovery by increased root dry wight and improved turf quality, as compared with the non-operated check plots.

• 한국항행학회논문지
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• 제12권6호
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• pp.539-547
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• 2008

본 논문에서는 연구용 ADS-B/TIS-B Validation Testbed(AVT)설계를 위한 기초 결과에 대하여 살펴본다. ADS-B는 GNSS와 디지털 데리터링크를 활용한 새로운 항공감시 개념이다. ADS-B는 종속적인 감시 개념이기 때문에 ADS-B송수신기를 장착하지 않은 항공기에 대한 감시 정보는 획득이 불가능하다. 기존의 이차감시레이더를 사용하여 획득한 감시정보를 제공하는 개념이 AIS-B이다. AVT는 ADS-B 및 ATS-B 개념을 기반으로 한 차세대 위성항행시스템의 감시 플랫폼이라는 의의가 있다.

• 한국멀티미디어학회논문지
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• 제18권2호
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• pp.189-198
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• 2015

Despite the fact that traffic engineering techniques have been comprehensively utilized in the past to enhance the performance of communication networks, the distinctive characteristics of Software Defined Networking (SDN) demand new traffic engineering techniques for better traffic control and management. Considering the behavior of traffic, large flows normally carry out transfers of large blocks of data and are naturally packet latency insensitive. However, small flows are often latency-sensitive. Without intelligent traffic engineering, these small flows may be blocked in the same queue behind megabytes of file transfer traffic. So it is very important to identify large flows for different applications. In the scope of this paper, we present an approach to detect large flows in real-time without even a short delay. After the detection of large flows, the next problem is how to control these large flows effectively and prevent network jam. In order to address this issue, we propose an approach in which when the controller is enabled, the large flow is mitigated the moment it hits the predefined threshold value in the control application. This real-time detection, marking, and controlling of large flows will assure an optimize usage of an overall network.

• 항공우주의학회지
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• 제29권2호
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• pp.67-71
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• 2019

The health of licence holders (flight crew members and air traffic controllers) is recognized as an important element of aviation safety. The medical emergency symptoms that occur during the flight duty period without prior notice can interfere with human performance capabilities and threaten aviation safety. To prevent this, ICAO has been required to conduct a periodic medical assessment process of licence holders including routine analysis of in-flight incapacitation events and medical findings during medical to identify areas of increased medical risk and continuous reevaluation of the medical assessment process to concentrate on identified areas of increased medical risk. The supply and demand of licence holders have become a major issue due to the increase in air traffic around the world, and the pilot retirement age has been extended to 65 years. But, there is no significant change in the aviation medical assessments process. The follow up of the result of medical examination discovered through aviation medical examination is a very important part, but it has not been properly implemented, and the sick leaves and medical inflight incapacitation reporting system should be improved. The management of health risk factors for licence holders must be implemented to prevent aircraft accidents or aviation safety problems caused by health problems. In this paper, we propose the development plan and concrete improvement plan of the health risk management system of licence holders in Korea in terms of aviation safety.

• 전자공학회논문지
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• 제51권3호
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• pp.89-101
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• 2014

최근 국내 항공교통량이 급증함에 따라 안전하고 효율적인 항공교통관리를 위한 항공관제 시스템의 필요성이 커지고 있다. 특히 원활한 항공교통관제를 위해 비행정보구역(FIR : Flight Information Region) 내의 모든 항공상황을 추가지연 없이 보여주어야 하는 현시시스템의 성능 보장이 무엇보다 중요하다. 본 논문에서는 표준 레이더 감시자료 포맷인 ASTERIX(All purpose STructured Eurocontrol suRveillance Information eXchange) 메시지의 파싱 과정에서 발생하는 오버헤드를 줄여 시스템 부하를 최소화함으로써 안정적인 관제운영을 도모할 수 있는 패턴매칭 기반의 ASTERIX 파싱 모듈을 설계하였다. 설계한 패턴매칭 기반의 ASTERIX 파싱 모듈은 수신 ASTERIX 데이터를 분석하여 패턴을 생성하며, 이후 수신되는 ASTERIX는 패턴을 통해 정의된 프로시저로 파싱한다. 기존 비트 수준 파싱 모듈의 불필요한 파싱 과정을 줄여 현시에 필요한 정보만을 빠르게 추출함으로써 현시 오류를 최소화하고 안정적인 항공관제를 가능하게 한다. 설계한 패턴매칭 기반의 ASTERIX 파싱 모듈의 성능을 비교하기 위하여 일반적인 비트 수준 ASTERIX 파싱 모듈과 비교한 결과, 짧은 처리지연시간, 높은 처리량, 낮은 CPU 사용률을 보이는 것을 확인하였다.

• 한국항공운항학회지
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• 제32권1호
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• pp.61-70
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• 2024

In response to the continuously increasing demand for air travel, various studies are being conducted. This research focuses on the design of a simulation model for improving airport slot allocation in the strategic phase. It addresses three aspects of model design, introducing considerations such as the objective function. Additionally, it explains the conceptual procedures for the overall simulation operation and detailed processes within the model including input and output data. Emphasizing the SAL, this study excludes policy and qualitative judgments from its scope. The target airport for application will be confirmed in future research. This study marks a crucial first step toward optimizing air traffic flow, with expectations of contributing to the enhancement of operational efficiency at airports.

• Industrial Engineering and Management Systems
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• 제13권2호
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• pp.172-184
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• 2014

Economic growth with rising household income has put more vehicles on the roads worsening traffic congestion, road accidents, and air and noise pollution. This situation is further aggravated by the potential working population who choose to drive to work instead of taking public transportation. Public bus transport (PBT) plays an important role in alleviating these problems. PBT is underutilized in Malaysia, and there is an opportunity to increase ridership without substantial investment. Therefore, this study was conducted to investigate the factors that influence the use of PBT in Malaysia. The data were collected using structured questionnaires from 400 respondents. The results of the analysis show that the twin factors consisting of perceived satisfaction of and perceived importance by users towards safety and comfort of facilities and services offered by PBT are significantly related to intention to use those services. The satisfaction of availability of season tickets, the importance of reliability of bus schedule and time table, and the importance of ticket pricing are also significant. By providing insights for both public bus operators and the government, this paper contributes to mitigate the underutilization of PBT in Malaysia and the consequences of putting more vehicles on the roads. From the theory perspective, this paper also contributes by extending the theory of reasoned-action to transportation studies.

• 한국항행학회논문지
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• 제26권6호
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• pp.434-440
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• 2022

ICAO (international civil aviation organization)에서는 전략적인 의사결정과 항공교통관리 평가를 위해 세계항행계획인 GANP (global air navigation plan) 수행을 체약국에게 권고하였다. 본 연구에서는 항공교통관리 평가를 위해 제시된 KPI (key performance indicator) 05 실제 항로 연장에서 항로거리를 구하는 새로운 방법을 제안하였다. 이를 위해 한 달간의 항적 데이터를 수집하고 ICAO에서 제시한 방법과 본 저자가 제시하는 방법으로 각각 항로거리를 산출하였다. ICAO 방법은 반경 40 NM 원형에 대한 원의 방정식과 항적 데이터 내 원에 근접한 내·외부 지점에 대한 직선의 방정식을 통하여 교점을 추정하여야 하고, 네 가지의 비행거리를 계산하여 항로거리를 산출한다. 본 연구에서 제시한 방법은 교점을 추정하지 않고 두 가지의 비행거리를 계산하여 항로거리를 산출한다. 두 방법의 오차를 확인하기 위해 회귀모형 성능평가지표인 RMSE (root mean square error)와 결정계수 R² 를 사용하였다.