• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.10-19
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• 2005

It may not be strange to anticipate that the forth-coming epoch of electronic government would bring us lots of convenience on account of ubiquitous environment with mobile devices. Such environment enables us to access the up-to-date information anytime and also a worker to carry out administration services to perform one's line of duty at anytime with electronic, handy devices such as PDA. What we now recognize from the field of electronic traffic administration services is that the office work flow as well as the public services has been remarkably improved by using of not only text but video and image information under the distributed, mobile environment. One of key requirements of this kinds of services is the feature of exchanging various information among multiple information publishers and subscribers. We call this feature Messaging Services generally The study in this paper focuses on the architecture design of the Messaging Engine software, complying with the pattern-oriented software architecture design methodology. And our contribution also goes to the discovery of three architecture patterns found in the design process and the efficient multi-threading architecture compared to one of the Messaging Engine solutions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1D
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• pp.23-31
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• 2012

Busan Metropolitan City government has been implementing the local Bus Quasi-Public Operating policy since 2007. As a result of the policy, financial burden to cover financial deficit has become a big social issue. For successful settlement of the policy, the government should be able to gradually cut off the financial support for the deficit by continuously increasing the bus demand, which can be accomplished by providing more convenient bus services. The weather conditions that affect the public transportation demand include rain, fog and snow. They affect the mode choice for public transportation use, which in turn results in decrease in bus demand. In short, the adverse weather conditions result in significant profit loss of bus transportation, and consequently it financially burdens the City of Busan. In this research, the pattern of travelers' use of transportation modes given various weather conditions was analyzed. In addition, the reasons why people transfer from one to other transportation modes were analyzed by conducting a field survey, and policy implications on desirable public transportation facilities and transfer system were discussed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.1
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• pp.56-73
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• 2019

Probe-based systems have been gaining popularity in advanced traveler information systems. However, the high possibility of providing inaccurate travel-time information due to the inherent time-lag phenomenon is still an important issue to be resolved. To mitigate the time-lag problem, different prediction techniques have been applied, but the techniques are generally regarded as less effective for travel times with high variability. For this reason, current 5-min aggregated data have been commonly used for real-time travel-time provision on highways with high travel-time fluctuation. However, the 5-min aggregation interval itself can further increase the time-lags in the real-time travel-time information equivalent to 5 minutes. In this study, a new scheme that uses both individual probe and 5-min aggregated travel times is suggested to provide reliable real-time travel-time information. The scheme utilizes individual probe data under congested conditions and 5-min aggregated data under uncongested conditions, respectively. As a result of an evaluation with field data, the proposed scheme showed the best performance, with a maximum reduction in travel-time error of 18%.

• Journal of Adhesion and Interface
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• v.19 no.4
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• pp.163-166
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• 2018

Dip-pen nanolithography(DPN) is an atomic force microscope (AFM) based method of generating nano- or micro-patterns. This technique has been used to transfer various ink materials on the substrate through water meniscus formed between AFM tip and the substrate surface. In this study, the heptadecafluoro-1,1,2,2-tetrahydrodecyltrimethoxysilane (HDFDTMS) ink materials were coated on the pre-coated AFM tip surface with the HDFDTMS molecules. When the tip brought into contact with the hydroxyl-functionalized silicon surface, HDFDTMS ink molecules have been successfully transported from the tip onto the surface via water meniscus. The created array and passivation area showed stable structures on the surface, and the transport of ink materials from the AFM tip to the surface followed linear increase in pattern size with contact time.

• Journal of Korean Society of Transportation
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• v.33 no.2
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• pp.113-124
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• 2015

The KOTI(Korea Transport Institute) released the new version of KTDB(Korea Transport DataBase) in public. The new KTDB is different from the past KTDB in using the concept of trip generation and trip attraction instead of using the concept of Origin-Destination (OD), which was used in the past KTDB. Thus, the appropriate analysis method for future travel demand became necessary for the new type of KTDB. The method should be based on the concept of PA(Production-Attraction). This study focused on analysis of trip generation and trip distribution related to newly generated trips by future land developments. The study also described clearly the standardized forecasting process and methods with PA travel tables. The study showed that the analysis results with OD-based analysis can be different from the results with PA-based analysis in forecasting travel demand for a simple example case even though they used exactly same orignal travel data. Therefore, this study emphasized that a proper method should be applied with the new PA-based KTDB. It is necessary to prepare and disseminate guidelines of the proper forecasting method and application with PA-based travel data for practician.

• Journal of Korean Society of Transportation
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• v.30 no.1
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• pp.31-43
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• 2012

Domestic road type-and period-specific driving pattern measurement was required as Korea's participation in developing "Worldwide harmonized light-duty vehicle emission test procedure (WLTP/DHC)" studied by UN WP29. This study measured road driving data reflecting road and traffic conditions of Korea, and analyzed seven types of representative road type-and period-specific driving patterns with driving pattern standardization methodology proposed by WP29. PAMS (Portable Activity Monitoring Systems) equipment was used to collect enormous (35,410km) road driving data. There are significant difference among seven derived driving patterns.

• Journal of Advanced Navigation Technology
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• v.22 no.1
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• pp.13-19
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• 2018

In this paper, we classified a flight pattern of unmanned aerial vehicle(UAV) which will be operating in UTM system and analyzed its flight pattern by purpose of use. Flight patterns of UAV are sorted into three patterns which are circling, monitoring and delivery. We considered four cases of industry areas using UAV which are agriculture, infrastructure monitoring, public safety & security(p.s.s) and delivery. It is necessary to build a simulation model as a verification tool for applying the flight pattern according to the use of UAV to the real UTM system. Therefore, we propose the simulation model of UAV with updating states over time. We applied simulation to UAV monitoring flight pattern, and confirmed that the flight was done by the given input data. The simulation model will be used in the future to verify that the UAV has various flight patterns and can operate safely and efficiently for the intended use.

• Journal of the Korean Geographical Society
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• v.44 no.2
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• pp.176-186
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• 2009

Transportation policy to facilitate the public mode use is of the foremost importance to the local governments of Metropolitan Seoul, regarding the economic and environmental consequences of the increasing use of car. Understanding the travel behaviour is essential to the establishment of proper policy to guide more people to the use of public modes instead of private. The paper reports a result of sequential analysis of individual travel behaviour in Metropolitan Seoul, using a multi-dimensional motif search technique applied to Smart Card data that integrates individuals' different public mode uses. Groups of travel patterns with similar sequential information identified distinctive travel behaviour between Seoul north and south and between metro and bus uses. Travel patterns are more bounded within north Seoul and south Seoul respectively than crossing Han River between north and south. Within north and south, travel patterns visiting northern CBD and southern CBD, respectively, as well as their local neighbour in north and south, often use metro and metro-local bus combination, while travel patterns visiting only the north and south locals without CBDs more use only the local bus line and even only the areal bus line.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.405-408
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• 2004

본 논문에서는 시간과 부하의 변화에 따라 편안한 승차감과 빠른 속도를 가질 수 있도록 다양한 속도 패턴을 제공하는 퍼지 알고리즘을 실제 공정에 적용할 수 있도록 SoC Design을 하였다. 운송 속도와 승차감은 엘리베이터 속도 패턴을 결정하기 위한 두개의 중요한 요소이며, 본 논문에서는 운송능력을 향상시키기 위해 교통량 변화에 맞춰서 저크를 조정하였다. 여기에서 구현된 퍼지 추론 시스템은 2개의 입력 변수와 1개의 출력을 가진 시스템이다. 전반부는 교통량의 변화를 나타내며, 시간 입력에 대해서 사다리꼴 형태의 소속함수를 사용하였다. 후반부는 입력에 대응되는 속도 패턴으로써, 싱글톤이 후반부에 적용되었다. 본 논문에서 구현 Tool 로는 SoC 설계를 사용하였다. SoC 설계는 현재 그 확장성과 유연성에 뛰어난 장점을 지니고 있으며, 제안된 알고리즘을 모듈로 설계하여 프로그래밍과 실행 사이클을 단축시키는 효과가 있다.

• Journal of Korean Society of Transportation
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• v.16 no.4
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• pp.153-166
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• 1998

본 연구에서는 도시 가로망에서의 구간 통행시간을 예측하기 위하여 time-frequency 분석의 일종인 웨이브렛변환과 RBF신경망 모형을 이용한 예측모형을 개발하였다. 웨이브렛 변환을 이용한 시계열 자료 분석을 통해서 통행시간에 내재되어 있는 다양한 패턴의 특징을 추출함으로써 오전/오후의 첨두현상, 신호교차로의 현시주기 등 주기적으로 발생되는 요인들에 의해서 통행시간 시계열 자료의 패턴에 나타나는 규칙성을 분석해 내었다. 분석된 패턴정보에 대한 규명은 카오스 이론을 근간으로한 시간지연좌표를 이용하여 시계열 자료의 규칙성을 시각적으로 판별하여 예측모형 구축에 활용하도록 하였다. 또, RBF신경망을 이용하여 예측범위의 공간적/시간적 확대에 따른 모형 구축에 소요되는 시간을 최소화하도록 하였으며, 시내버스 노선의 정류장간 운행시간 예측을 통해서 기존 연구에서 제기되었던 현실세계의 단순화, 다단계 예측시 정확성 등의 문제를 해결하였다. 예측실험결과 웨이브렛 변환을 데이터의 전처리 과정에 삽입하여 링크 통행시간의 패턴정보 예측에 활용할 경우, 기존의 예측모형에 비해서 훨씬 정확한 예측이 가능한 것으로 나타났으며, RBF 신경망은 짧은 학습시간에도 불구하고 역전파 신경망보다 우수한 예측력을 갖고 있는 것으로 밝혀졌다.