• Journal of Information Processing Systems
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• v.13 no.4
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• pp.951-969
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• 2017

In this paper, we newly propose a traffic information service model that collects traffic information sensed by an individual vehicle in real time by using a smart device, and which enables drivers to share traffic information on all roads in real time using an application installed on a smart device. In particular, when the driver requests traffic information for a specific area, the proposed driver-personalized service model provides him/her with traffic information on the driving directions in advance by predicting the driving directions of the vehicle based on the learning of the driving records of each driver. To do this, we propose a traffic information management model to process and manage in real time a large amount of online-generated traffic information and traffic information requests generated by each vehicle. We also propose a road node-based indexing technique to efficiently store and manage location-based traffic information provided by each vehicle. Finally, we propose a driving learning and prediction model based on the hidden Markov model to predict the driving directions of each driver based on the driver's driving records. We analyze the traffic information processing performance of the proposed model and the accuracy of the driving prediction model using traffic information collected from actual driving vehicles for the entire area of Seoul, as well as driving records and experimental data.

• Journal of Korean Society of Rural Planning
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• v.4 no.1
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• pp.32-39
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• 1998

In Korea, rural village improvement has mainly been led by goverment investment. This approach, however, has its own limit since there are so many village to be improved while the budgetary sources are restricted, As an alternative, inducement of private investments to these area is considered in order to promote rural village improvement. The possibility of inducing private investments to the rural village improvement depends on the location of the village. The possibility may be highest in the sub-urban area since expected benefits from land development is usually high. One desirable approach to induce private investment to these area is the cooperative development system. Residents, private investors and governments plays its own role, independently and cooperatively, But benifits from the investment to improve rural village in general plain area are so low that it is difficult to induce the private investments to these area. In that case, indirect development system will be a proper strategy which maintaining government-led development method as usual, expanding the participation of private developers such as the construction companies. In general, rate of returns from investment to the rural sectors is lower than that to the other sectors, therefore financial support such as the long- term, low loan rate and a partial value-added tax exemption should be given to the investors to the rural village improvement projects.

• Korean Journal of Applied Biomechanics
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• v.23 no.2
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• pp.131-139
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• 2013

Naejirgi is one of the fastest, most forceful and most often being used kicks in Taekkyon games, The purpose of this study was to investigate kinetic factors on two types of Naejirgi kick, one of which uses knee bending of supporting leg and the other uses little it. 12 taekkyoners (11 males and one female) who are the students of Y University participated in this study. They have been practicing on Taekkyon for five years or more. Positions of CoM, the elapsed time of each phase, vertical ground reaction forces, joint moments and impulses of supporting leg were analyzed for this study. The results were as follows; in Naejirgi with knee bending of supporting leg than without knee bending of supporting leg, the vertical motion range of whole body CoM was larger during phase 2 and 3, the elapsed time of phase 4 were longer, players stayed longer in the nearest location to opponent, during phase 4 the vertical ground reaction forces of supporting foot were larger, and joint extension moments and angular impulses of supporting leg (especially knee) were larger. In conclusion supporting knee bending is not a useful strategy for Naejirgi, because players stay longer in the nearest position to opponent and consumed more muscle force and energy for producing the vertical momentum which is unnecessary for pushing down the opponent.

• Smart Structures and Systems
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• v.25 no.3
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• pp.345-368
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• 2020

The present work proposes a self-controlled multi-stage optimization method for damage identification of structures utilizing standard particle swarm optimization (PSO) algorithm. Damage identification problem is formulated as an inverse optimization problem where damage severity in each element of the structure is considered as optimization variables. An efficient objective function is formed using the first few frequencies and mode shapes of the structure. This objective function is minimized by a self-controlled multi-stage strategy to identify and quantify the damage extent of the structural members. In the first stage, standard PSO is utilized to get an initial solution to the problem. Subsequently, the algorithm identifies the most damage-prone elements of the structure using an adaptable threshold value of damage severity. These identified elements are included in the search space of the standard PSO at the next stage. Thus, the algorithm reduces the dimension of the search space and subsequently increases the accuracy of damage prediction with a considerable reduction in computational cost. The efficiency of the proposed method is investigated and compared with available results through three numerical examples considering both with and without noise. The obtained results demonstrate the accuracy of the present method can accurately estimate the location and severity of multi-damage cases in the structural systems with less computational cost.

• Journal of The Geomorphological Association of Korea
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• v.24 no.2
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• pp.91-101
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• 2017

Quantitative forecasting methods based on spatial data and geographic information system have been used in predicting the landslide location. This study compared the simulated results of logistic, Bayesian, and maximum entropy models to understand the uncertainties of each model and identify the main factors that influence landslide. The study area is Boeun gun where 388 landslides occurred in the year of 1998. The verification results showed that the AUC of the three models was 0.84. However, the landslide susceptibility distribution of Maxent model was different from those of the other two models. With the same landslide occurrence data, the result of high susceptible area in Maxent model is smaller than Logistic or Bayesian. Maxent model, however, proved to be more efficient in predicting landslide than the other two models. In Maxent's simulations, the responsible factors for landslide susceptibility are timber age class, land cover, timber diameter, crown closure, and soil drainage. The results suggest that it is necessary to consider the possibility of overestimation when using Logistic or Bayesian model, and forest management around the study area can be an effective way to minimize landslide possibility.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.3
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• pp.304-320
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• 2019

Interest in gazelle-firms, which contribute to sustained job creation, is increasing. This study aims to analyze the regional characteristics of employment by gazelle-firms in terms of job quality as well as job quantity. Furthermore, the characteristics by industry for each type are compared. The major results are as follows. First, the regional characteristics of job creation are varied in terms of the quantitative and qualitative aspects. Second, it is found that the characteristics by industry for each type are different. Therefore, each type should have discriminative strategy. These results provide policy implications that gazelle-firms' policies should be tailed to regional characteristics in order to foster gazelle-firms more effectively.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.4
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• pp.427-433
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• 2019

This paper propose a fuzzy inference model for map building and navigation for a mobile robot with an active camera, which is intelligently navigating to the goal location in unknown environments using sensor fusion, based on situational command using an active camera sensor. Active cameras provide a mobile robot with the capability to estimate and track feature images over a hallway field of view. In this paper, instead of using "physical sensor fusion" method which generates the trajectory of a robot based upon the environment model and sensory data. Command fusion method is used to govern the robot navigation. The navigation strategy is based on the combination of fuzzy rules tuned for both goal-approach and obstacle-avoidance. To identify the environments, a command fusion technique is introduced, where the sensory data of active camera sensor for navigation experiments are fused into the identification process. Navigation performance improves on that achieved using fuzzy inference alone and shows significant advantages over command fusion techniques. Experimental evidences are provided, demonstrating that the proposed method can be reliably used over a wide range of relative positions between the active camera and the feature images.

• The Plant Pathology Journal
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• v.35 no.5
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• pp.459-472
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• 2019

The increasing variation in climatic conditions under climate change directly influences plant-microbe interactions. To account for as many variables as possible that may play critical roles in such interactions, the use of an integrated modeling approach is necessary. Here, we report for the first time a local impact assessment and adaptation study of future epidemics of kiwifruit bacterial blossom blight (KBB) in Jeonnam province, Korea, using an integrated modeling approach. This study included a series of models that integrated both the phenological responses of kiwifruit and the epidemiological responses of KBB to climatic factors with a 1 km resolution, under the RCP8.5 climate change scenario. Our results indicate that the area suitable for kiwifruit cultivation in Jeonnam province will increase and that the flowering date of kiwifruit will occur increasingly earlier, mainly due to the warming climate. Future epidemics of KBB during the predicted flowering periods were estimated using the Pss-KBB Risk Model over the predicted suitable cultivation regions, and we found location-specific, periodic outbreaks of KBB in the province through 2100. Here, we further suggest a potential, scientifically-informed, long-term adaptation strategy using a cultivar of kiwifruit with a different maturity period to relieve the pressures of future KBB risk. Our results clearly show one of the possible options for a local impact assessment and adaptation study using multiple models in an integrated way.

• Smart Structures and Systems
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• v.23 no.1
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• pp.61-69
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• 2019

Offshore structures are generally exposed to harsh environments such as strong tidal currents and wind loadings. Monitoring the structural soundness and integrity of offshore structures is crucial to prevent catastrophic collapses and to prolong their lifetime; however, it is intrinsically challenging because of the difficulties in accessing the critical structural members that are located under water for installing and repairing sensors and data acquisition systems. Virtual sensing technologies have the potential to alleviate such difficulties by estimating the unmeasured structural responses at the desired locations using other measured responses. Despite the usefulness of virtual sensing, its performance and applicability to the structural health monitoring of offshore structures have not been fully studied to date. This study investigates the use of virtual sensing of offshore structures. A Kalman filter based virtual sensing algorithm is developed to estimate responses at the location of interest. Further, this algorithm performs a multi-sensor data fusion to improve the estimation accuracy under non-stationary tidal loading. Numerical analysis and laboratory experiments are conducted to verify the performance of the virtual sensing strategy using a bottom-fixed offshore structural model. Numerical and experimental results show that the unmeasured responses can be reasonably recovered from the measured responses.

• Journal of Distribution Science
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• v.19 no.2
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• pp.15-24
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• 2021

Purpose: The research is to find out the perception of consumers for the convenience store (c - store) image in an emerging market, with a sample from Ho Chi Minh City. Research design, data, and methodology: Data were collected using a 24 - item structured questionnaire into six factors, namely: store atmospheric, merchandise, supplementary service, customer convenience, sales personnel, promotion. Five hundred consumers shopped at the different c - stores were collected for a multidimensional scaling technique that creates a perceptual map illustrating of c - store image. Results: The results point out that consumers' perception of a different c - store is different. The trend of c- stores are focusing on the dimensions of the function aspect. The customers also put their attention on the psychological dimension, which, in this case, is customer convenience with a sharp point. Almost all stores are bad on store atmospheric in customer- based. Conclusions: The modern retail store chains need to focus on elements to create a store image positioning and improve the perceptions of the consumers towards the store. Besides, customers not only visit the stores, not due to its convenient location, mass media or shopping experience, but also a strong identity for the store's brand image.