• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.4
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• pp.186-198
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• 2016

HPAI(Highly Pathogenic Avian Influenza) is a contagious animal disease that spreads rapidly by diffusion after the first occurrence. The disease has brought tremendous social costs and economic losses. KAHIS (Korea Animal Health Information System) is the integrated system for supporting the task of preventing epidemics. They provide decision-support information, recording vehicle visiting times and facility location, etc., which is possible by enforcing registration of all livestock related facilities and vehicles. KAHIS has accumulated spatial and temporal information that enables effective tracing of potential disease trajectories and diffusion through vehicle movements. The contact network is created utilizing spatial and temporal information in KAHIS to inform facility connection via vehicle visitation. Based on the contact network, it is possible to infer spatial and temporal mechanism of disease spread and diffusion. The study objective is to empirically demonstrate how to utilize primary spatial and temporal information in KAHIS in the form of the contact network. Based on the contact network, facilities with the possibility of infection can be pinpointed within the potential spatial and temporal extent where the disease has spread and diffused. This aids the decision-making process in the task of preventing epidemics. By interpreting our demonstration results, policy implications were presented. Finally, some suggestions were made to comprehensively utilize the contact network to draw enhanced decision-support information.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.163-168
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• 2020

In this paper we propose a The purpose of this study was to examine the psychological characteristics of youth mobile phone use. Internally, we want to find out about self-regulation, interpersonal relationship, pleasure, and desire to achieve reality. For the research, the Korea Information Society Agency utilized 568 data based on self-control and user motivation among long-term tracking data of Internet and mobile phone addiction in 2018. The SPSS window 23 version was used for data analysis, and the data collected were analyses to identify the subject's demographic characteristics. In addition, the correlation of variables between groups was investigated by analyzing dummy variables, and the results of the study were as follows. First, the addiction was slightly higher in mobile phone game groups than in social network service (SNS) groups, but in the same period of use, social network service (SNS) groups showed a higher desire for interpersonal relationships. In the desire to avoid reality, mobile phone game groups showed a higher gap than social network service (SNS) However, there was no difference between groups in terms of pleasure and desire to achieve. The results of this study indicated that the content of mobile phone use differed in factors affecting mobile phone overuse, and suggestions for follow-up research were discussed.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.121-130
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• 2004

In these days, multiple-path generation method is highly demanded in practice and research areas, which can represents realistically travelers behavior in choosing possible alternative paths. The multiple-path generation algorithm is one of the key components for policy analysis related to ATIS, DRGS and ATMS in ITS. This study suggested a method to generate multiple Possible paths from an origin to a destination. The approach of the suggested method is different from an other existing methods(K-shortest path algorithm) such as link elimination approach, link penalty approach and simulation approach. The result of the multi-label vine-building shortest path algorithm(MVA) by Kim (1998) and Kim(2001) was used to generate multiple reasonable possible paths with the concept of the rational upper boundary. Because the MVA algorithm records the cost, back-node and back-back node of the minimum path from the origin to the concerned node(intersection) for each direction to the node, many potential possible paths can be generated by tracing back. Among such large number of the potential possible paths, the algorithm distinguishes reasonable alternative paths from the unrealistic potential possible paths by using the concept of the rational upper boundary. The study also shows the very simple network examples to help the concept of the suggested path generation algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.336-339
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• 2011

In the RTLS(Real Time Location Based System), in case of existing a number of moving target, extremely complecated data flow is can be occurred. In the network where single gateway exists, various data which was collected from sensor node is transmitted along the simple route as time goes by. In case of multi-gateway configuration, the collected data is transmitted through diverse routes rather than simple route. This kind of data causes jams on nodes and this brings down the performance of the network. Different from existing studies, in this thesis, MAC (Media Access Control) protocol which minimizes data collision between nodes and guarantees QoS(Quality of Service) is suggested, in order to communicate efficiently in multi-gateway underwater sensor network environment. In the suggested protocol, source node which wants to transmit data makes a channel reservation to a number of destination node using a RTS packet. Source node reserves a channel without collision, by scheduling CTS response time using expected delay information from neighbor nodes. Once the reservation is made, source node transmit data packet without collision. This protocol analyzes/estimates the performance compared to a method provided from existing studies via simulation. As a results of the analysis, it was comfirmed that the suggested method has better performance, such as efficiency and delay.

• Journal of Korea Spatial Information System Society
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• v.8 no.2 s.17
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• pp.91-107
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• 2006

To handling the extreme situation that must manage positional information of a very large volume, at least millions of moving objects. A cluster-based sealable distributed computing system architecture, called the GALIS which consists of multiple data processors, each dedicated to keeping records relevant to a different geographical zone and a different time zone, was proposed. In this paper, we proposed a valid time management and time-zone shifting scheme, which are essential in realizing the long-term location data subsystem of GALIS, but missed in our previous prototype development. We explain how to manage valid time of moving objects to avoid ambiguity of location information. We also describe time-zone shifting algorithm with three variations, such as Real Time-Time Zone Shifting, Batch-Time Zone Shifting, Table Partitioned Batch-Time Zone Shifting, Through experiments related with query processing time and CPU utilization, we show the efficiency of the proposed time-zone shifting schemes.

• Journal of Digital Convergence
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• v.13 no.3
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• pp.65-73
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• 2015

The purpose of this study is to examine the relationship between sustainable PLM(Product Lifecycle Management) activity and performance. To ensure this purpose, we designed the S-PLM Framework which is consisted of traditional PLM activity and sustainable PLM activity. We also conducted path analysis to investigate PLM success factor on manufacturing company and to understand the relationship between these success factors. First the result of analysis of the relationship between traditional PLM activity and sustainable performance. Second, there is significantly positive relationship between sustainable activity and performance. Third, traditional PLM activity and sustainable PLM activity factor have an influence on the innovation performance factor. Fourth, sustainable performance have an effect on the management and business performance. In conclude we analyzed and verified the influence sustainable PLM establishment mechanism and the sustainable PLM activity factors. Therefore this study is to create innovative performance and to improve efficiency of Convergence PLM establishment and operation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.808-814
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• 2010

In this paper we executed a SBL(Short Baseline) underwater acoustic positioning system that is a kind of underwater position estimation system to estimates the 3-dimensional position of ROV(Remotely Operated Vehicle) using hydrophones and DAQ(Data Acquisition) system in the basin which dimensions are $3{\times}3{\times}1.7(m)$. For this experiment, we let 4 hydrophones in different positions of the basin for receiver and 1 hydrophone is fixed on the underwater vehicle for transmitting sensor(pinger). These five hydrophones are communicated with each other to find the 3-D positions of the moving ROV in the basin. The measured signals are collected by DAQ system and the positions of the ROV are plotted by LabView program in real-time. To estimate the position of the ROV we used a trigonometric method. In X and Y plane the estimated data has a small errors but in Z plane the estimated data has large errors so we cannot use this data for position control. One solution of this problem is using depth sensor that implemented of the underwater vehicle. Hereafter, we will test in the ocean using designed SBL system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.57-58
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• 2023

The working time for loading and transporting containers in the container terminal is one of the factors directly related to port productivity, and minimizing working time for these operations can maximize port productivity. Among working time for container operations, the working time of yard tractors(Y/T) responsible for the transportation of containers between berth and yard is a significant portion. However, it is difficult to estimate the working time of yard tractors quantitatively, although it is possible to estimate it based on the practical experience of terminal operators. Recently, a technology based on IoT(Internet of Things), one of the core technologies of the 4th industrial revolution, is being studied to monitoring and tracking logistics resources within the port in real-time and calculate working time, but it is challenging to commercialize this technology at the actual port site. Therefore, this study aims to develop yard tractor working time prediction model to enhance the operational efficiency of the container terminal. To develop the prediction model, we analyze actual port operation data to identify factors that affect the yard tractor's works and predict its working time accordingly.

• Childhood Kidney Diseases
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• v.13 no.1
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• pp.40-48
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• 2009

Purpose : This study was performed to identify factors related to the resolution of primary vesicoureteral reflux (VUR) in infants. Methods : We reviewed 183 infants (M : F=149 : 34) diagnosed as urinary tract infection (UTI) between February 2002 and July 2007 at Sanggye Paik Hospital. The diagnosis of UTI was made by culture from a urine specimen obtained by suprapubic puncture (n=97), catheterization (n=83), or collection bag method (n=3, twice positive culture of same organism). All of the infants were performed renal ultrasonography, DMSA scan and voiding cystourethrography (VCUG) study. Follow-up imaging consisted of contrast VCUG or direct isotope VCUG at interval of 1 year. We evaluated the relationship of clinical and laboratory finding, radiologic finding in infants with VUR. Results : Among 51 VUR patients, 18 infants had grade I-II, 12 infants had grade III and the other 21 patients had grade IV-V. Abnormal findings including hydronephrosis on renal ultrasonography were not correlated with severity of VUR. However, the incidence of renal defect in the first DMSA scan showed a tendency of direct correlation with severity of VUR in female patients only (P<0.001). There was significant difference of resolution rate in three VUR groups (grade I-II, III, IV-V) in male patients only (P=0.025). Resolution rate was higher for male patients with unilateral VUR than bilateral (P<0.001). But unilaterality had not any affect on VUR resolution in female VUR patients (P=0.786). Resolution rate was higher for VUR patients without renal scar than VUR patients with renal scar (P<0.001). Conclusion : According to our findings, grade of VUR, laterality and renal scar are the factors that contribute to resolution of primary VUR in male and female infants differently.

• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.500-505
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• 2005

Purpose : This study was designed to estimate the prevalence of Mycoplasma pneumoniae infection during an epidemic period by means of examining the antibody conversion rate and to investigate the association of the antibody conversion with age, initial antibody titer, and atopy. Methods : We chose 191 children whose antibody titer to M. pneumoniae was negative, 1 : 40, or 1 : 80 during the first half of 2003. After the second half of 2003 when the M. pneumoniae epidemic occurred, follow-up collection of sera was performed during the first half of 2004. M. pneumoniae antibody titer was measured by Serodia-Myco II particle agglutination test. Results : Of 191 children, antibody conversion was detected in 83 children(43.5 percent). No significant difference was found between the conversion and non-conversion group with respect to age, sex and atopy. Dividing the subjects into four groups by age, results on the antibody conversion rate revealed no significant differences between the groups. Assessed by initial antibody titer, a diminished trend of conversion rate was observed in children with 1 : 80 titer but the difference was not significant. There was no significant difference in the antibody conversion rate between atopic and non-atopic children. Conclusion : Based on the antibody conversion rate in this study, the prevalence of M. pneumoniae infection during an epidemic period was estimated to be 43.5 percent. This high infection rate suggests that during an epidemic, we should bear in mind M. pneumoniae as an important etiologic agent for respiratory infection in children.