• Proceedings of the Korea Multimedia Society Conference
• /
• 2000.04a
• /
• pp.206-209
• /
• 2000

XML은 웹에서 구조화된 문서를 기술하는 전세계적인 표준 메타 언어로 정교한 검색을 지원하며, 쉽게 다른 목적으로 사용될 수 있다. Java는 다양한 플랫폼을 갖는 원격 학습 환경에서 효율적이면서도 안전하고 다양한 기능을 수행하는 시스템을 구현할 수 있게한다. 따라서 다양한 멀티미디어 구성요소들을 포함하는 코스웨어를 원격에서 교사들이 쉽게 개발하고 관리할 수 있는 XML 기반의 원격 코스웨어 제작 및 관리 시스템(X/RCAMS : SML-based Remote Courseware Authoring and Management System)을 Java 언어로 구현하기위하여 설계를 하였다. 이 시스템은 한 학교나 학습지 지역 분국에서 자신의 특성을 살리면서도 학습 정보의 상호 교류가 가능하며, 사용자가 사용하기 쉽고 사용자의 능동적인 참여를 유발할 수 있다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.13 no.2
• /
• pp.225-231
• /
• 2013

A bird's-eye view is an elevated view of an object from above, with a perspective as though the observer were a bird, often used in the making of blueprints, floor plans and maps. It can be used under severe weather conditions when visibility is poor. Under low visibility environments, drivers can communicate each other using V2V communication to get each vehicle's status to prevent collision and other accidents. Ubiquitous transportation sensor networks(u-TSN) and its application are emerging rapidly as an exciting new paradigm to provide reliable and comfortable transportatione services. The ever-growing u-TSN and its application will provide an intelligent and ubiquitous communication and network technology for traffic safety area.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.4
• /
• pp.91-103
• /
• 2016

The work zone traffic management is of keen interest because the unstable traffic stream in work zones leads to not only less productive traffic operational efficiency but also negative impacts on traffic safety. A promising method to address such issues is variable speed limit systems(VSLS). VSLS is expected to increase in throughput and to enhance safety by diminishing the crash potential. In addition, the usefulness of VSLS has been demonstrated by significant amount of existing literature. The objective of this study is to identify the effectiveness of VSLS based on a meta analysis technique. Throughput and travel speed were used as measures of effectiveness for VSLS in terms of the operational efficiency and safety respectively. Results showed that approximately 16.4% increase in throughput and 16.5% decrease in travel speed were obtainable by VSLS. The outcomes of this study would be useful in developing technologies and polices for better operation of VSLS.

• Journal of KIISE:Software and Applications
• /
• v.26 no.12
• /
• pp.1393-1403
• /
• 1999

공간 데이타베이스 시스템을 통하여 공유되는 공간 데이타는 무결성이 적절하게 유지되지 않는 한 전체 응용 시스템의 행위를 예측할 수 없게 되므로 데이타의 무결성 확인 및 유지는 필수적이다. 특히 공공 GIS에 저장된 공간 데이타는 토지 이용도 평가, 도시 계획, 자원 관리, 시설물 관리, 안전 관리, 국방 등 국가 전체 및 지역의 중요한 정책 결정을 위한 다양한 응용 시스템들에 의해 이용되므로 적절한 공간 객체의 무결성 확인이 더욱 더 필요하다. 본 논문에서는 능동(active) DBMS의 능동 규칙(active rule) 기법을 이용하여 공간 객체의 무결성 확인을 지원하기 위한 규칙 관리 시스템을 제시한다. 능동 규칙을 이용한 공간 객체의 무결성 확인은 응용 프로그래머를 무결성 확인에 대한 부담으로부터 자유롭게 할 수 있다. 본 시스템은 특정 DBMS에 종속되지 않는 독립적인 외부 시스템으로 존재하며, 능동 규칙 관리기, 규칙 베이스, 그리고 활성규칙 생성기의 3 부분으로 구성된다. 사용자가 공간 데이타베이스 응용 프로그램을 통해 공간 객체를 조작하고자 할 때, 본 시스템은 데이타베이스 트랜잭션을 단위로 조작되는 모든 공간 객체의 무결성 확인을 위해 응용 프로그램에 삽입될 무결성 제약조건 규칙들을 효율적으로 관리하는 역할을 한다.Abstract It is necessary that the integrity of spatial data shared through the spatial database system is validated and appropriately maintained, otherwise the activity of whole application system is unpredictable. Specially, the integrity of spatial data stored in public GIS has to be validated, because those data are used by various applications which make a decision on an important policy of the region and/or whole nation such as evaluation of land use, city planning, resource management, facility management, risk management/safety supervision, national defense. In this paper, we propose rule management system to support validating the integrity of spatial object, using the technique of active rule technique from active DBMS. Validating data integrity using active rules allows database application programmer to be free from a burden on validation of the data integrity. This system is an independent, external system that is not subject to specific DBMS and consists of three parts, which are the active rule manager, the rule base, and the triggered rule generator. When an user tries to manipulate spatial objects through a spatial database application program, this system serves to efficiently manage integrity rules to be inserted into the application program to validate the integrity constraints of all the spatial objects manipulated by database transactions.

• The Journal of the Korea Contents Association
• /
• v.14 no.9
• /
• pp.45-53
• /
• 2014

In this study, we analyzed the next generation ITS (C-ITS) technology trends, focusing on the national and international C-ITS projects. Based on the promotion practices of developed countries, we pointed out the lack of linkages with the existing ITS infrastructure. As a way to overcome this problem, we proposed the three-direction to enable the existing ITS infrastructure corresponding to the C-ITS. First one is developing a technique to improve the performance of the existing ITS infrastructure and automate the performance management (Performance-enhanced ITS). Second, developing active sensors or fusion sensor which along with V2X communication technology implement of an active safety driving support system (Safety-enhanced ITS). Third, we need to develop a technology that generate the new advanced traffic data by integrating the collected data from existing ITS infrastructure and nomadic device (Cloud-ITS). By improving the function of the existing ITS infrastructure for adaptation to the new V2X communication environment, we enhanced the efficiency of maintenance performance and would maximize the benefit of the introduction of C-ITS.

• Journal of Navigation and Port Research
• /
• v.44 no.6
• /
• pp.494-500
• /
• 2020

Maneuvering vessels in the harbor is an interesting problem in marine cybernetics. The vessel, operated by the pilot and moving very slowly in shallow water, usually is assisted by thrusters, the main propulsion system, and tugboats. In this paper, we suggest a new vessel berthing technique using dampers (cylinder-type fenders) and a system of winches for complex and dangerous berthing situations. We found that control of the fender stroke and rope tension enabled a safe and quick berthing process. The effectiveness and usefulness of this berthing system was verified using a ship of about 2,000 tons.

• Journal of Auto-vehicle Safety Association
• /
• v.5 no.2
• /
• pp.24-31
• /
• 2013

This paper describes a coordinated control algorithm for rear-side collision avoidance. In order to assist driver actively and increase driver's safety, the proposed coordinated control algorithm is designed to combine lateral control using a steering torque overlay by Motor Driven Power Steering (MDPS) and differential braking by Vehicle Stability Control (VSC). The main objective of a combined control strategy is twofold. The one is to prevent the collision between the subject vehicle and approaching vehicle in the adjacent lanes. The other is to limit actuator's control inputs and vehicle dynamics to safe values for the assurance of the driver's comfort. In order to achieve these goals, the Lyapunov theory and LMI optimization methods has been employed. The proposed coordinated control algorithm for rear-side collision avoidance has been evaluated via simulation using CarSim and MATLAB/Simulink.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.7 no.4
• /
• pp.25-35
• /
• 2008

Variable Message Sign(VMS) is one of the subsystem of Intelligent Transportation Systems (ITS), which is useful for providing real-time information on weather, traffic and highway conditions. However, there are various situations such as incidents/accidents, constructions, special events, etc., which would be occurred on segments, it is unable to control traffic with only the VMS. Thus, it is essential to use of PVMS(Portable Variable Message Signs), which can move to the location needed traffic control and provide more active traffic information than VMS. This study developed a legibility distance model for PVMS messages using in-vehicle Differential Global Positioning Data(DGPS). Traffic conditions, drivers' characteristics, weather conditions and characteristics of PVMS message were investigated for establishing the legibility model based on multiple linear regression analysis. The factors such as height of PVMS characters, spot speed, age, gender and day and night were identified as dominants affecting the variation of legibility distances. It is expected that the proposed model would play a significant role in designing PVMS messages for providing more effective real-time traffic information.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2015.05a
• /
• pp.501-501
• /
• 2015

댐과 같은 수공구조물의 치수능력부족은 구조물의 파손이나 붕괴로 직결되며, 대규모 재산피해와 인명피해가 불가피하다. 또한 최근 기후변화 현상에 의해 발생되고 있는 예상치 못한 큰 강우와 홍수는 댐 안전을 저하하는 요소로 간주되며, 복합적으로 발생시 댐의 치수능력이 크게 저하되어 댐 파괴에 영향을 미칠 가능성이 크다. 또한 ICOLD, 세계대댐회 등의 조사 결과 댐 파괴에 큰 영향을 미치고 있는 수문학적 요소로서 예상치 못한 강우, 홍수 및 월류로 조사되었다. 이러한 이유로 수문학적 위험인자를 효과적으로 고려하기 위해 2000년도 이후 선진국에서는 위험도 해석 기법을 기반으로 파괴모드, 다양한 하중조건 등을 조합하여 위험도 해석을 통해 댐의 안전도 검토를 실시하고 있다. 따라서 최근 증가하는 기상변동성을 능동적으로 고려하기 위해서는 위험도 해석기반의 수공구조물 안정성 평가기법을 기반으로 하는 종합적인 위험도 해석 방안수립이 요구된다. 이러한 이유로 본 연구에서는 BN 모형 기반의 댐 위험도 적용에 앞서 실증댐을 대상으로 분석을 수행하였으며, 분석 절차는 다음과 같다. 첫째, ICOLD 및 세계대댐회 등 다양한 논문, 보고서 등을 조사하여 댐 붕괴에 가장 큰 영향을 미치는 수문학적 파괴인자를 도출하였다. 둘째, BN 모형 구축시 각 노드는 앞서 도출된 수문학적 파괴인자를 이용하였으며, 각 파괴인자에 적합한 확률분포형을 부여하였다. 마지막으로, 노드별 임계값을 부여하여 상황별 파괴인자의 변화 양상을 도출하였다. 본 연구의 결과로 인해 연구대상댐의 가장 취약한 수문학적 파괴인자 도출이 가능하며, 댐의 보수 보강시 우선순위 의사결정의 지원이 가능 할 것으로 판단된다.

• Journal of Korean Society of Transportation
• /
• v.30 no.4
• /
• pp.95-106
• /
• 2012

Driver's capability of identifying the change in freeway alignments and environments is one of important factors associated with traffic safety on freeways. In particular, driver's visibility and recognition capability are highly dependent on the altitude of the sun by sunset, sunrise, and nighttime. The purpose of this study is to identify the characteristics of geometric conditions affecting crash occurrences at sunset, sunrise, and nighttime. Poisson and negative binomial regressions were adopted to predict freeway crash frequency in this study. Freeway crash data during 2007~2010 were used for developing the crash frequency models. A set of variables representing the characteristics of geometric conditions were identified as significant ones affecting crash occurrences. The results of this study would be useful in deriving effective countermeasures for preventing traffic crashes that mainly occur at sunset, sunrise, and nighttime on freeways.