• Journal of Digital Convergence
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• v.13 no.8
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• pp.321-329
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• 2015

This study investigates effects of hardware and telecommunication and software service divided by ICT service on each 5 transportations to explore convergence of ICT and Transportation. Research models are production inducing effects, Added Value inducing effects of Demand-Driven model and Shortage cost effects of Supply-Driven model by using data for 2010~2012 of Input-Output Table. Results are that network and software service effects are more impact than hardware effects on transportations. Especially, hardware is impacted heavily on production inducing effect, telecommunications and software services has had a significant impact on the production inducing effect and Shortage cost effects. In addition, by each detail the transportation industries, packages and other transport and road transport is influenced greatly from ICT. On the other hand, rail and water transport are relatively lower impact by ICT, However, the effects of rail and water transport by ICT is grater than investment ratio of ICT. As a result, increasing investment in the ICT services could contribute to development of rail and water transport development.

• Journal of Digital Convergence
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• v.16 no.5
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• pp.43-53
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• 2018

Recently, public service for the improvement of quality of life and life support such as safety, aging, disaster, welfare, housing, economy, urban environment, traffic etc are actively developed based on open public data, and the spread of the network and the necessity of everyday life, smartphones are playing a role in providing public services. Currently, the development of science is changing the life expectancy of human beings and changing into social structure in which aged people become bigger due to various social conditions and low fertility and aging problems. However, the elderly who do not have easy access to information are very uncomfortable in dealing with mobile devices with very low accessibility and utilization of public services provided by mobile phones. Therefore, this study recategorizes the condition of the elderly presented in the previous study and identifies the problem through case analysis provided for the elderly. Also, we summarize the hierarchy of the core items of the existing interface design and derive it as an improvement index of the public service design for the improvement of the information accessibility of the elderly, and propose a design method to improve the utilization of the public service provided through the mobile device.

• The Journal of Society for e-Business Studies
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• v.15 no.2
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• pp.137-166
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• 2010

A virtual team is defined a group of people that use electronic communications for some or all of their interactions with other team members. Because team members of a virtual team are physically and temporally distributed, a team's transactive memory system(TMS) is considered to be crucial for the team's effectiveness and performance. TMS refers to a set of individual memory systems which integrate knowledge possessed by particular members through a shared awareness of who knows what. This paper seeks to understand (1) how a virtual team's TMS influences team performance, and (2) what factors contribute to developing the team's TMS. Given these purposes, through the extensive literature review, we first identified components and antecedents to develop a theoretical model that predicts a virtual team's performance. Using the survey data gathered from 172 virtual teams, this study found that expertise location, coordination, and cognition-based trust which were proposed as three components of TMS positively influenced a virtual team's performance. Furthermore, this study uncovered that perceived media richness, network tie strength, and shared norms significantly influenced the components of TMS, while geographical dispersion did not exert any significant influence on TMS.

• Journal of Korea Water Resources Association
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• v.53 no.7
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• pp.493-505
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• 2020

The rainfall-runoff model has been generally adopted to obtain a consistent runoff sequence with the use of the long-term ground-gauged based precipitation data. The Thiessen polygon is a commonly applied approach for estimating the mean areal rainfall from the ground-gauged precipitation by assigning weight based on the relative areas delineated by a polygon. However, spatial bias is likely to increase due to a sparse network of the rain gauge. This study aims to generate continuous runoff sequences with the mean areal rainfall obtained from radar rainfall estimates through a PRMS rainfall-runoff model. Here, the systematic error of radar rainfall is corrected by applying the G/R Ratio. The results showed that the estimated runoff using the corrected radar rainfall estimates are largely similar and comparable to that of the Thiessen. More importantly, one can expect that the mean areal rainfall obtained from the radar rainfall estimates are more desirable than that of the ground in terms of representing rainfall patterns in space, which in turn leads to significant improvement in the estimation of runoff.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.33-42
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• 2020

There has been difficulties in identifying objects by relying on the naked eye in various surveillance systems. There is a growing need for automated surveillance systems to replace soldiers in the field of military surveillance operations. Even though the object detection technology is developing rapidly in the civilian domain, but the research applied to the military is insufficient due to a lack of data and interest. Thus, in this paper, we applied one of deep learning algorithms, Convolutional Neural Network-based binary classification to develop an autonomous identification model of both friend and foe helicopters (AH-64, Mi-17) among the military weapon systems, and evaluated the model performance by considering accuracy, precision, recall and F-measure. As the result, the identification model demonstrates 97.8%, 97.3%, 98.5%, and 97.8 for accuracy, precision, recall and F-measure, respectively. In addition, we analyzed the feature map on convolution layers of the identification model in order to check which area of imagery is highly weighted. In general, rotary shaft of rotating wing, wheels, and air-intake on both of ally and foe helicopters played a major role in the performance of the identification model. This is the first study to attempt to classify images of helicopters among military weapons systems using CNN, and the model proposed in this study shows higher accuracy than the existing classification model for other weapons systems.

• Journal of Digital Convergence
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• v.15 no.11
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• pp.547-555
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• 2017

The purpose of this research is to examine the relationships between online and offline social capital and psychological well-being of university students. Data came from 236 university students who attended 4-year universities in Seoul and had used Social Network Service. The results of this study indicated that only offline social capital was statistically significant to predict psychological well-being including depression and happiness when both online and offline social capital variables were entered. In detail, the university students' depression was associated with their gender, satisfaction with their economic status, and offline bridging social capital. In addition the students' happiness was associated with their satisfaction with their economic status, offline bridging, and bonding social capital. These results indicate that offline social capital is more important for improving psychological well-being of university students compared to online social capital. Policy implications for improving psychological well-being of university students are discussed.

• Informatization Policy
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• v.24 no.2
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• pp.68-86
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• 2017

This research aims to analyze the changes in participants' capacity (problem-solving ability and self-leadership), humanity (self-efficacy), and global network (intercultural sensitivity) as performance indicators and the 'effectiveness of personal characteristics' of the World Friends IT Volunteers program. To do this, the study conducted a pre-test and a post-test on 364 participants of the World Friends IT Volunteers program. The collected data is investigated through ANCOVA using covariates, driven from the prerest results. The results of this study represent that meaningful improvements have been identified in problem-solving ability, self-leadership and intercultural sensitivity since the operation of the program. Regarding the personal characteristics, performance in the female group improved more than the male group in terms of intercultural sensitivity, whereas the male group showed better performance on self-efficacy than the female group. In addition, the group with a high level of English proficiency showed more progress on intercultural sensitivity and self-leadership than the English-beginner group. Besides, the group who had an experience of short-term stay overseas showed moderate improvement on problem-solving ability and intercultural sensitivity when compared to other groups. The group who had lived overseas for a long-term showed better indicators on intercultural sensitivity. Also, self-efficacy of the leader group was more noticeable than that of the member group.

• Journal of the Korean association of regional geographers
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• v.22 no.3
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• pp.553-565
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• 2016

Population aging has been an increasing social issue and the elderly health has become one of the most urgent public attentions in Korea. The aims of this paper are to compare the subjective health status according to the personal characteristics, social networks, and daily leisure activities of the urban-rural elderly, and to analyze the influencing factors of their subjective health status. Using 2011 elderly survey data, ordered logit Model was established to extract influencing factors of the elderly health status. The results show that socioeconomic and demographic characteristics of individual as well as frequent social contacts and daily activities within neighborhood environments influence the level of health status of the elderly. The most significant factors affecting the elderly health are personal economic conditions such as the education achievement level and household income. The elderly who visit an elderly welfare center in Seoul has almost 1.82 times higher odds of increasing health status level than not to visit an elderly welfare center. This study may give some important policy implications of the elderly health promotion strategy in urban-rural communities.

• International Journal of Highway Engineering
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• v.17 no.4
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• pp.11-18
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• 2015

PURPOSES: This study aims to evaluate the runoff reduction with permeable pavements using the SWMM analysis. METHODS: In this study, simulations were carried out using two different models, simple and complex, to evaluate the runoff reduction when an impermeable pavement is replaced with a permeable pavement. In the simple model, the target area for the analysis was grouped into four areas by the land use characteristics, using the statistical database. In the complex model, simulation was performed based on the data on the sewer and road network configuration of Yongsan-Gu Bogwang-Dong in Seoul, using the ArcGIS software. A scenario was created to investigate the hydro-performance of the permeable pavement based on the return period, runoff coefficient, and the area of permeable pavement that could be laid within one hour after rainfall. RESULTS : The simple modeling analysis results showed that, when an impervious pavement is replaced with a permeable pavement, the peak discharge reduced from $16.7m^3/s$ to $10.4m^3/s$. This represents a reduction of approximately 37.6%. The peak discharge from the whole basin showed a reduction of approximately 11.0%, and the quantity decreased from $52.9m^3/s$ to $47.2m^3/s$. The total flowoff reduced from $43,261m^3$ to $38,551m^3$, i.e., by approximately 10.9%. In the complex model, performed using the ArcGIS interpretation with fewer permeable pavements applicable, the return period and the runoff coefficient increased, and the total flowoff and peak discharge also increased. When the return period was set to 20 years, and a runoff coefficient of 0.05 was applied to all the roads, the total outflow reduced by $5195.7m^3$, and the ratio reduced to 11.7%. When the return period was increased from 20 years to 30 and 100 years, the total outflow reduction decreased from 11.7% to 8.0% and 5.1%, respectively. When a runoff coefficient of 0.5 was applied to all the roads under the return period of 20 years, the total outflow reduction was 10.8%; when the return period was increased to 30 and 100 years, the total outflow reduction decreased to 6.5% and 2.9%, respectively. However, unlike in the simple model, for all the cases in the complex model, the peak discharge reductions were less than 1%. CONCLUSIONS : Being one of the techniques for water circulation and runoff reduction, a high reduction for the small return period rainfall event of penetration was obtained by applying permeable pavements instead of impermeable pavement. With the SWMM analysis results, it was proved that changing to permeable pavement is one of the ways to effectively provide water circulation to various green infrastructure projects, and for stormwater management in urban watersheds.

• Journal of KIISE
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• v.43 no.12
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• pp.1428-1436
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• 2016

A multipath routing in wireless sensor networks (WSNs) provides advantage such as reliability improvement and load balancing by transmitting data through divided paths. For these reasons, existing multipath routing protocols divide path appropriately or create independent paths efficiently. However, when the sink node moves to avoid hotspot problem or satisfy the requirement of the applications, the existing protocols have to reconstruct multipath or exploit foot-print chaining mechanism. As a result, the existing protocols will shorten the lifetime of a network due to excessive energy consumption, and lose the advantage of multipath routing due to the merging of paths. To solve this problem, we propose a multipath creation and maintenance scheme to support the mobile sink node. The proposed protocol can be used to construct local grid structure with restricted area and exploit grid structure for constructing the multipath. The grid structure can also be extended depending on the movement of the sink node. In addition, the multipath can be partially reconstructed to prevent merging paths. Simulation results show that the proposed protocol is superior to the existing protocols in terms of energy efficiency and packet delivery ratio.