• Information and Communications Magazine
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• v.31 no.3
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• pp.103-116
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• 2014

This paper proposes the design of Vehicular Cyber-Physical Systems (called VCPS) based on vehicular cloud for smart road networks. Our VCPS realizes mobile cloud computing services where vehicles themselves or mobile devices (e.g., smartphones and tablets of drivers or passengers in vehicles) play a role of both cloud server and cloud client in the vehicular cloud. First, this paper describes the architecture of vehicular networks for VCPS and the delay modeling for the event prediction and data delivery, such as a mobile node's travel delay along its navigation path and the packet delivery delay in vehicular networks. Second, the paper explains two VCPS applications as smart road services for the driving efficiency and safety through the vehicular cloud, such as interactive navigation and pedestrian protection. Last, the paper discusses further research issues for VCPS for smart road networks.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.376-378
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• 2002

현재 클라이언트/서버 네트워크 환경은 시스템이 점점 대형화되면서 유지보수 및 네트워크 트래픽에 대한 문제로 인하여 분산 객체 개념을 이용한 분산 환경의 페러다임이 필요하게 되었다. 이에 OMG의 CORBA는 분산 환경을 위한 표준을 제공하며, 분산 객체간의 비동기 호출을 위한 이벤트 서비스를 명시하고 있다. 분산 객체간의 데이터 전송은 전체 시스템의 성능을 좌우하는 중요한 요인으로 평가받고 있으나 이벤트 서비스는 이벤트 데이터를 위한 필터링 기능을 제공하고 있지 않아 비효율적인 데이터 전송을 하고 있다. 본 논문에서는 이벤트 채널의 필터링을 위한 모듈을 정의하여 기존의 서비스에서 제공하는 이벤트 채널보다 효율적인 데이터 전송이 가능한 이벤트 필터링 채널을 설계한다.

• Nuclear Engineering and Technology
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• v.31 no.2
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• pp.226-235
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• 1999

Applying digital network technology for advanced nuclear plant requires deterministic communication for tight safety requirements, timely and reliable data delivery for operation-critical and mission-critical characteristics of nuclear plant. Communication protocols, such as IEEE 802/4 Token Bus, IEEE 802/5 Token Ring, FDDI, and ARCnet, which have deterministic communication capability are partially applied to several nuclear power plants. Although digital communication technologies have many advantages, it is necessary to consider the noise immunity from electromagnetic interference (EMI), electrical interference, impulse noise, and heat noise before selecting specific digital network technology for nuclear plant. In this paper, we consider the token frame loss and data frame loss rate due to the link error event, frame size, and link data rate in different protocols, and evaluate the possibility of failure to meet the hard real-time requirement in nuclear plant.

• Journal of Information Processing Systems
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• v.13 no.5
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• pp.1229-1242
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• 2017

In this paper, an interference aware distributed multi-channel MAC (IDMMAC) protocol is proposed for wireless sensor and actor networks (WSANs). The WSAN consists of a huge number of sensors and ample amount of actors. Hence, in the IDMMAC protocol a lightweight channel selection mechanism is proposed to enhance the sensor's lifetime. The IDMMAC protocol divides the beacon interval into two phases (i.e., the ad-hoc traffic indication message (ATIM) window phase and data transmission phase). When a sensor wants to transmit event information to the actor, it negotiates the maximum packet reception ratio (PRR) and the capacity channel in the ATIM window with its 1-hop sensors. The channel negotiation takes place via a control channel. To improve the packet delivery ratio of the IDMMAC protocol, each actor selects a backup cluster head (BCH) from its cluster members. The BCH is elected based on its residual energy and node degree. The BCH selection phase takes place whenever an actor wants to perform actions in the event area or it leaves the cluster to help a neighbor actor. Furthermore, an interference and throughput aware multi-channel MAC protocol is also proposed for actor-actor coordination. An actor selects a minimum interference and maximum throughput channel among the available channels to communicate with the destination actor. The performance of the proposed IDMMAC protocol is analyzed using standard network parameters, such as packet delivery ratio, end-to-end delay, and energy dissipation, in the network. The obtained simulation results indicate that the IDMMAC protocol performs well compared to the existing MAC protocols.

• Women's Health Nursing
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• v.15 no.2
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• pp.140-149
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• 2009

Purpose: The purposes of this phenomenological study were to explore the experience of preterm labor. Methods: The participants were 7 women admitted to two obstetric hospitals in Kyunggi-do Province with preterm labor. Data was collected with MP3 records through individual in-depth interviews and participated observation. The data was analyzed by Giorgi(1985) method. Results: The results were divided into six categories as follows: 1) Inappropriate coping: unexpected event, overwork, lack of insight of preterm labor, 2) Burn out: multiple role, burden, role conflict. 3) Restrictions of lifestyle: uncomfortable hospital environment, wearisomeness, limitations of personal hygiene, 4) Physical discomfort: headache, flush, tremor, palpitations, 5) Psychological distress : concerns about fetus health status, fear of possible preterm delivery, lack of information, financial worries, 6) A transition to new lifestyle: share of household chores, communication with self-help group, careful lifestyle. Conclusion: The findings of this study will offer a better understanding of women's preterm labor experiences and suggest clues to nurses on how to improve the care they provide.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.463-467
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• 2015

Mega-shock means a sporadic event such as the earning shock, which occurred by sudden market changes, and it can cause serious problems of profit loss of international construction projects. Therefore, the early response and prevention by analyzing and predicting the Mega-shock is critical for successful project delivery. This research is preliminary study to develop a prediction model that supports market condition analysis and Mega-shock forecasting. To avoid disadvantages of classic statistical approaches that assume the market factors are linear and independent and thus have limitations to explain complex interrelationship among a range of international market factors, the research team explored the Fractal Theory that can explain self-similarity and recursiveness of construction market changes. The research first found out correlation of the major market factors by statistically analyzing time-series data. The research then conducted a base of the Fractal analysis to distinguish features of fractal from data. The outcome will have potential to contribute to building up a foundation of the early shock warning system for the strategic international project management.

• Journal of the Korea Society for Simulation
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• v.32 no.1
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• pp.1-11
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• 2023

Smart factory environments and digital twin environments are established, and today's factories accumulate vast amounts of production data and are managed in real time as visualized results suitable for user convenience. Production simulation techniques are in the spotlight as a way to prevent delays in delivery and predict factory volatility in situations where production schedule planning becomes difficult due to the diversification of production products. With the development of the digital twin environment, new packages are developed and functions of existing packages are updated, making it difficult for users to make decisions on which packages to use to develop simulations. Therefore, in this study, the concept of Discrete Event Simulation (DES) performed based on discrete events is defined, and the characteristics of various simulation packages were compared and analyzed. To this end, studies that solved real problems using discrete event simulation software for 10 years were analyzed, and three types of software used by the majority were identified. In addition, each package was classified by simulation technique, type of industry, subject of simulation, country of use, etc., and analysis results on the characteristics and usage of DES software were provided. The results of this study provide a basis for selection to companies and users who have difficulty in selecting discrete event simulation package in the future, and it is judged that they will be used as basic data.

• Journal of the Korea Society for Simulation
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• v.29 no.3
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• pp.73-82
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• 2020

In the fourth industrial revolution, wireless sensor networks (WSNs) are an important element of collecting and analyzing data in a variety of environments without human intervention. This sensor network is greatly affected by topology and routing protocols. Routing protocols, which affect energy consumption, are executed after deploying sensor nodes. Once built, they are difficult to change. Before the WSN is deployed, a routing protocol is carefully selected in view of various environments and the performance of the protocol is evaluated. In this paper, we propose a model to simulate multiple routing protocols using a discrete event system specification (DEVS). The DEVS-based proposed model simulates various situations without changes and structures of the its model as algorithms of the routing protocols are implemented in its coordinators model. To verify normal behaviors of the proposed model, the number of report delivery and the energy consumption of the sensor network were compared using representative protocols LEACH and Dijkstra. As a result, it was confirmed that the proposed model executes normally in both routing protocols.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.336-337
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• 2016

FHIR is a protocol that enables easy data exchange from the time the event occurred in health care settings as a standard for next-generation message exchange of HL7. Create a meaningful message from the ECG and medical equipment, and express the messages generated by standardized FHIR message it will be used in various medical institutions to ensure delivery to EMR, such as hospital information systems can query the results via a smartphone.

• The Korean Journal of Emergency Medical Services
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• v.17 no.2
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• pp.9-20
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• 2013

Purpose: The purpose of this study is to provide basic data to improve prehospital emergency care for patients with labor pain, vaginal bleeding and rape experience by analyzing the reports of 119 emergency medical technicians. Methods: Data were prehospital reports of 190 patients having chief complaints of labor pain, vaginal bleeding and rape in Chungcheongnam-do from January 1, 2012 to December 31, 2012. Data were analyzed using SPSS 21.0 descriptive statistics and $x^2$-test. Results: From the 190 cases of labor pain, vaginal bleeding and rape, labor pain accounted for 57.9% including 75.5% of normal delivery; vaginal bleeding accounted for 35.8% including 26.5% of postpartum hemorrhage; and rape victims accounted for 6.3%. Cases with more than one vital sign accounted for 94.2%, but cases without primary assessment of the obstetrics and gynaecology accounted for 38.4% from gestation weeks, 78.0% from parity, and 87.4% from history taking relating to event. Patient care including emotional support was the first priority care accounted for 78.4% and 60% of care was keeping the patients warm. Conclusion : In order to handle various emergency situations properly, the records must be supplemented by obstetrical and gynaecological rape checklist and rape victims supporting system should be established.