• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.5
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• pp.251-259
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• 2014

In this paper, we propose Low Energy Service Discovery (LESD) protocol for common discovery mode of IEEE 802.15.8 Peer Aware Communications (PAC). In order to minimize power consumption, Basic Repetition Block (BRB) is defined. Device is able to select operating mode and synchronize other devices through it. Proposed MAC procedure is Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) based on overhearing technique. Even if device has not been received response signal since transmitted request signal, it is able to discover other devices of same group through the overhearing technique. IEEE 802.15.8 PAC has required that performances of common discovery mode are presented about discovered devices during the simulation time, discovery latency and average power consumption. By considering the number of devices per group and channel environment, two scenarios are evaluated through system level simulation and the simulation results of proposed scheme are compared with CSMA/CA in same simulation conditions. As a result, proposed scheme is able to get high energy efficiency of devices as well as increase the number of discovered devices during simulation time when the longer the number of devices is distributed over a limited area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.374-380
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• 2017

The Internet of Things (IoT) refers to intelligent technologies and services that connect all things to the internet so they can interactively communicate with people, other things, and other systems. The development of the IoT environment accompanies advances in network protocols applicable to more lightweight and intelligent sensors, and lightweight and diverse environments. The development of those elemental technologies is promoting the rapid progress in smart car environments that provide safety features and user convenience. These developments in smart car services will bring a positive effect, but can also lead to a catastrophe for a person's life if security issues with the services are not resolved. Although smart cars have various features with different types of communications functions to control the vehicles under the existing platforms, insecure features and functions may bring various security threats, such as bypassing authentication, malfunctions through illegitimate control of the vehicle via data forgery, and leaking of private information. In this paper, we look at types of smart car services in the IoT, deriving the security threats from smart car services based on various scenarios, suggesting countermeasures against them, and we finally propose a safe smart car application plan.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.5
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• pp.1-10
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• 2014

This research focuses on the warrants for the Two-Way Left-Turn Lanes (TWLTL). Using a microscopic traffic simulation tool, two key parameters were investigated herewith. One is a wide range of the Design Hourly Volume (DHV), reflective of recent Korean roadway volume characteristics, that is conventionally reduced from the Average Daily Traffic (ADT). The other is driveway spacing, the length of the middle-lane section where two conflicting left-turn demands often compete for space. In addition, unlike previous researches, the way and the procedure the TWLTL operation is realized in the VISSIM S/W with its add-on application such as VISVAP is clearly stated and described in detail. According to the result of simulations for 10 volume scenarios, as expected, the higher the volume level is, the more delay the left-tuner experience. The Level Of Service (LOS) for most cases was in the range of C and D based on the non-signalized intersection LOS criteria. Furthermore, the TWLTL was found operable up to the volume level of 1,116 and 1,860 vph in heavy direction (equivalent of volume level 7) for 3-lane and 5-lane facility respectively, which covers significant portion of existing two to four-lane highway volumes in Korea.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.2
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• pp.47-59
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• 2017

This study aims to assess offshore wind energy resources around Jeju Island using the InVEST Offshore Wind model. First the wind power density around the coast of Jeju was calculated using reanalysis data from the Korean Local Analysis and Prediction System (KLAPS). Next, the net present value (NPV) for the 168MW offshore wind farm scenario was evaluated taking into consideration factors like costs (turbine development, submarine cable installation, maintenance), turbine operation efficiency, and a 20year operation period. It was determined that there are high wind resources along both the western and eastern coasts of Jeju Island, with high wind power densities of $400W/m^2$ calculated. To visually evaluate the NPV around Jeju Island, a classification of five grades was employed, and results showed that the western sea area has a high NPV, with wind power resources over $400W/m^2$. The InVEST Offshore Wind model can quickly provide optimal spatial information for various wind farm scenarios. The InVEST model can be used in combination with results of marine ecosystem service evaluation to design an efficient marine spatial plan around Jeju Island.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.5
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• pp.531-538
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• 2016

Driving behaviors such as speeding and illegal u-turn which violate traffic rules are main causes of car accidents, and they can lead to serious accidents. Bus drivers are less aware of dangers of illegal u-turn, and infrastructures such as traffic enforcement equipment and watchmen are deficient. This research aims to develop technology for estimating driving behaviors based on map-matching in order to prevent illegal u-turns. For this research, 23,782 of u-turn permit data and 146,000 of speed limit data are collected nationwide, and an estimation algorithm is built with these data. Then, an application based on android is developed, and finally, tests are conducted to assess the accuracy in data computations and GPS data map-matching, and to extrapolate driving behavior. As a result of the tests, the accuracy results in the map-matching is 86% and the assessment of driving behavior is 83%, while the display of the data output yielded 100% accuracy. Additional research should focus on improvement in accuracy through the development of a robust monitoring system, and study of service scenarios for technology application.

• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.348-356
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• 2007

The purpose of this study is to give the results of economic feasibility of industrial forest plantations, and also A/R CDM project in Indonesia to investors. In order to analyze economic feasibility of the industrial forest plantation and A/R CDM project, this study comparatively analyzes the feasibility based on three following scenarios: industrial plantation type; A/R CDM type; combination type of industrial plantation and A/R CDM project. In the aspect of IRR, the combination type has 11 % while the industrial plantation type has 8%. If the price of timber increases USD $5/m^3$ (from the standard price: USD $30/m^3$ to USD $35/m^3$), IRR of the industrial plantation type will increase from 8% to 14%. This result shows us that the IRR of the industrial plantation type is very sensitive to the price of timber. There is no economic feasibility of A/R CDM project if the price of lCER is under USD 5. In addition, IRR of the A/R CDM project type is the same to IRR of industrial plantation type (8%) when the price of lCER is USD 10. Finally, the total investment expenditure on 12,000ha of the combination type is approximately 13 billion won while the industrial plantation type is 13.6 billion won. It takes 11 year to reach the turning point in terms of profitability of the combination type while the industrial plantation takes 13 year. Thus, the economic feasibility of the combination type is higher than the other types(industrial plantation type and A/R CDM project type).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.240-247
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• 2020

The Korean military is having difficulty maintaining combat power due to the insufficient troop numbers caused by a demographic cliff and the reduction of the mandatory military service period. Recently, discussions on improving the military training system have increased significantly. This paper proposes an optimization model to establish military training schedules to improve combat power. The oblivion and learning effects on training tasks were quantified through a survey and applied to the model. The objective value, combat power, was calculated based on the total task scores of the unit members and the number of task failures after four weeks. The scenarios were configured by the change in educational conditions and initial scores of some tasks. As a result of scenario experiments, combat power has increased by at least 10% and up to 77%, which is sufficient to maintain combat power considering the change in troops. In addition, the planning of combat skill tasks has a significant impact on combat power. Through this research model, it is expected that military training managers will be able to establish a training schedule that maintains or improves the combat power of troops effectively.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.3
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• pp.245-256
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• 2017

Objectives: The present study is aimed at performing real-time measurement of fibrous materials using an F-1 fiber monitor, investigating the correlations between the measurements and environmental conditions, and assessing the feasibility of the use of the monitor in actual exposure assessments based on the accuracy and reliability of the device. Methods: Asbestos specimens with a fixed asbestos content were dispersed in a chamber and collected with a particle measuring test device. Measurements obtained by the existing PCM method, and with the F-1 fiber monitor were compared. In addition, concentrations of asbestos fibers obtained by the PCM method, the TEM method, and the F-1 fiber monitor were compared with that of specific ABS scenarios in NOA regions. Correlations of asbestos contents in soil and weather conditions with each method of measurement were analyzed. Results: Laboratory results showed that levels of asbestos fibers measured with each method increased as fiber contents in soil increased. In the accuracy and reproducibility assessment, no significant differences were found between the different methods of measurement. On-site assessment results showed positive correlations among the methods, and these correlations were less significant compared with what was shown by the laboratory results. Levels of asbestos fibers increased as asbestos contents in soil increased, and as temperature increased. Levels of asbestos fibers decreased as humidity increased, and wind speed did not significantly affect the extent to which asbestos fibers were scattered. Conclusions: While it would be premature to replace existing methods with the use of F-1 fiber monitors in real sites based on the results of this study, the monitor may be useful in the screening of the sites, which assesses hazard levels in different regions. Replacement of existing methods with the use of F-1 fiber monitors may be possible after the limitations identified in this study are overcome, and additional assessment data are obtained and reviewed under different conditions to confirm the reliability of the monitor in future research. Obtained assessment results may be used as basic data for the assessment of asbestos hazard in NOA regions.

• Journal of the Society of Disaster Information
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• v.1 no.1
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• pp.3-26
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• 2005

In recent years, there is growing concern about the potential use of biological agents in war or acts of terrorism accompanied an increased realization that rapid preparedness and response are needed to prevent or treat the human damage that can be caused by these agents. The threat is indeed serious, and the potential for devastating numbers of casualties is high. The use of agents as weapons, even on a small scale, has the potential for huge social and economic disruption and massive diversion of regional and national resources to combat the threat, to treat primary disease, and to clean up environmental contamination. Biological weapons are one of weapons of mass destruction (or mass casualty weapons, to be precise. since they do not damage non-living entities) that are based on bacteria, viruses, rickettsia, fungi or toxins produced by these organisms. Biological weapons are known to be easy and cheap to produce and can be used to selectively target humans, animals, or plants. Theses agents can cause large numbers of casualties with minimal logistical requirements (in wide area). The spread of disease cannot be controlled until there is awareness of the signs of infection followed by identification of agents; and if the organism is easily spread from person to person, as in the case of smallpox, the number of casualties could run into the tens of thousands. Biological weapons could be used covertly, there can be a lot of different deployment scenarios. A lot of different agents could be used in biological weapons. And, there are a lot of different techniques to manufacture biological weapons. Terrorist acts that make use of Biological Agents differ in a number of ways from those involving chemicals. The distinction between terrorist and military use of Biological Weapon is increasingly problematic. The stealthy qualities of biological weapons further complicate the distinction between terrorism and war. In reality, all biological attacks are likely to require an integrated response involving both military and civilian communities. The basic considerations when public health agencies establish national defence plan against bioterrorism must be 1) arraying various laws and regulations to meet the realistic needs, 2)education for public health personnels and support of concerned academic society, 3)information collection and cooperative project with other countries, 4)Detection and surveillance(Early detection is essential for ensuring a prompt response to biological or chemical attack, including the provision of prophylactic medicines, chemical antidotes, or vaccines) and 5) Response(A comprehensive public health response to a biological or chemical terrorist event involves epidemiologic investigation, medical treatment and prophylaxis for affacted persons, and the initiation of disease prevention or environmental decontamination measures). The purpose of this paper is providing basic material of preparedness and response for biological terrorism in modern society.

• Journal of Korea Spatial Information System Society
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• v.10 no.3
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• pp.79-91
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• 2008

Recently, with highly Interest In Location-Based Service(LBS) utilizing location data of moving objects, the GALIS(Gracefully Aging Location Information System) which is a cluster-based distributed computing architecture was proposed as a more efficient location management system of moving objects. In the SLDS(Short-term location Data Subsystem) which Is a subsystem of the GALIS, since the SDP(Short-term Data Processor) Master transmits current location data and queries to every SDP Worker, the SDP Master reassembles and sends query results produced by SDP Workers to the client. However, the services are suspended during the SDP Master under failure and the response time to the client is increased if the load is concentrated on the SDP Master. Therefore, in this paper, the extended SLDS was designed and implemented to solve these problems. Though one SDP Master is under failure, the other can provide the services continually, and so the extended SLDS can guarantee the high reliability of the SLDS. The extended SLDS also can reduce the response time to the client by enabling two SDP Masters to perform the distributed query processing. Finally, we proved high reliability and high availability of the extended SLDS by implementing the current location data storage, query processing, and failure takeover scenarios. We also verified that the extended SLDS is more efficient than the original SLDS through the query processing performance evaluation.