• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.3-16
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• 2008

A Wireless Sensor Network (WSN for short) is a wireless network consisting of distributed small devices which are called sensor nodes or motes. Recently, there has been an extensive research on WSN and also on its security. For secure storage and secure transmission of the sensed information, sensor nodes should be equipped with cryptographic algorithms. Moreover, these algorithms should be efficiently implemented since sensor nodes are highly resource-constrained devices. There are already some existing algorithms applicable to sensor nodes, including public key ciphers such as TinyECC and standard block ciphers such as AES. Stream ciphers, however, are still to be analyzed, since they were only recently standardized in the eSTREAM project. In this paper, we implement over the MicaZ platform nine software-based stream ciphers out of the ten in the second and final phases of the eSTREAM project, and we evaluate their performance. Especially, we apply several optimization techniques to six ciphers including SOSEMANUK, Salsa20 and Rabbit, which have survived after the final phase of the eSTREAM project. We also present the implementation results of hardware-oriented stream ciphers and AES-CFB fur reference. According to our experiment, the encryption speeds of these software-based stream ciphers are in the range of 31-406Kbps, thus most of these ciphers are fairly acceptable fur sensor nodes. In particular, the survivors, SOSEMANUK, Salsa20 and Rabbit, show the throughputs of 406Kbps, 176Kbps and 121Kbps using 70KB, 14KB and 22KB of ROM and 2811B, 799B and 755B of RAM, respectively. From the viewpoint of encryption speed, the performances of these ciphers are much better than that of the software-based AES, which shows the speed of 106Kbps.

• Journal of Intelligence and Information Systems
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• v.18 no.4
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• pp.117-127
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• 2012

Due to the recent expansion of the Web 2.0 -based services, along with the widespread of smartphones, online social network services are being popularized among users. Online social network services are the online community services which enable users to communicate each other, share information and expand human relationships. In the social network services, each relation between users is represented by a graph consisting of nodes and links. As the users of online social network services are increasing rapidly, the SNS are actively utilized in enterprise marketing, analysis of social phenomenon and so on. Social Network Analysis (SNA) is the systematic way to analyze social relationships among the members of the social network using the network theory. In general social network theory consists of nodes and arcs, and it is often depicted in a social network diagram. In a social network diagram, nodes represent individual actors within the network and arcs represent relationships between the nodes. With SNA, we can measure relationships among the people such as degree of intimacy, intensity of connection and classification of the groups. Ever since Social Networking Services (SNS) have drawn increasing attention from millions of users, numerous researches have made to analyze their user relationships and messages. There are typical representative SNA methods: degree centrality, betweenness centrality and closeness centrality. In the degree of centrality analysis, the shortest path between nodes is not considered. However, it is used as a crucial factor in betweenness centrality, closeness centrality and other SNA methods. In previous researches in SNA, the computation time was not too expensive since the size of social network was small. Unfortunately, most SNA methods require significant time to process relevant data, and it makes difficult to apply the ever increasing SNS data in social network studies. For instance, if the number of nodes in online social network is n, the maximum number of link in social network is n(n-1)/2. It means that it is too expensive to analyze the social network, for example, if the number of nodes is 10,000 the number of links is 49,995,000. Therefore, we propose a heuristic-based method for finding the shortest path among users in the SNS user graph. Through the shortest path finding method, we will show how efficient our proposed approach may be by conducting betweenness centrality analysis and closeness centrality analysis, both of which are widely used in social network studies. Moreover, we devised an enhanced method with addition of best-first-search method and preprocessing step for the reduction of computation time and rapid search of the shortest paths in a huge size of online social network. Best-first-search method finds the shortest path heuristically, which generalizes human experiences. As large number of links is shared by only a few nodes in online social networks, most nods have relatively few connections. As a result, a node with multiple connections functions as a hub node. When searching for a particular node, looking for users with numerous links instead of searching all users indiscriminately has a better chance of finding the desired node more quickly. In this paper, we employ the degree of user node vn as heuristic evaluation function in a graph G = (N, E), where N is a set of vertices, and E is a set of links between two different nodes. As the heuristic evaluation function is used, the worst case could happen when the target node is situated in the bottom of skewed tree. In order to remove such a target node, the preprocessing step is conducted. Next, we find the shortest path between two nodes in social network efficiently and then analyze the social network. For the verification of the proposed method, we crawled 160,000 people from online and then constructed social network. Then we compared with previous methods, which are best-first-search and breath-first-search, in time for searching and analyzing. The suggested method takes 240 seconds to search nodes where breath-first-search based method takes 1,781 seconds (7.4 times faster). Moreover, for social network analysis, the suggested method is 6.8 times and 1.8 times faster than betweenness centrality analysis and closeness centrality analysis, respectively. The proposed method in this paper shows the possibility to analyze a large size of social network with the better performance in time. As a result, our method would improve the efficiency of social network analysis, making it particularly useful in studying social trends or phenomena.

• Asia pacific journal of information systems
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• v.23 no.3
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• pp.25-53
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• 2013

This study analyzes the effect of Computer Aided Innovation (CAI) to improve R&D Capabilities empirically. Survey was distributed by e-mail and Google Docs, targeting CTO of 235 SMEs. 142 surveys were returned back (rate of return 60.4%) from companies. Survey results from 119 companies (83.8%) which are effective samples except no-response, insincere response, estimated value, etc. were used for statistics analysis. Companies with less than 50billion KRW sales of entire researched companies occupy 76.5% in terms of sample traits. Companies with less than 300 employees occupy 83.2%. In terms of the type of company business Partners (called 'partners with big companies' hereunder) who work with big companies for business occupy 68.1%. SMEs based on their own business (called 'independent small companies') appear to occupy 31.9%. The present status of holding IT system according to traits of company business was classified into partners with big companies versus independent SMEs. The present status of ERP is 18.5% to 34.5%. QMS is 11.8% to 9.2%. And PLM (Product Life-cycle Management) is 6.7% to 2.5%. The holding of 3D CAD is 47.1% to 21%. IT system-holding and its application of independent SMEs seemed very vulnerable, compared with partner companies of big companies. This study is comprised of IT infra and IT Utilization as CAI capacity factors which are independent variables. factors of R&D capabilities which are independent variables are organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability. The highest average value of variables was 4.24 in organization capability 2. The lowest average value was 3.01 in IT infra which makes users access to data and information in other areas and use them with ease when required during new product development. It seems that the inferior environment of IT infra of general SMEs is reflected in CAI itself. In order to review the validity used to measure variables, Factors have been analyzed. 7 factors which have over 1.0 pure value of their dependent and independent variables were extracted. These factors appear to explain 71.167% in total of total variances. From the result of factor analysis about measurable variables in this study, reliability of each item was checked by Cronbach's Alpha coefficient. All measurable factors at least over 0.611 seemed to acquire reliability. Next, correlation has been done to explain certain phenomenon by correlation analysis between variables. As R&D capabilities factors which are arranged as dependent variables, organization capability, process capability, HR capability, technology-accumulating capability, and internal/external collaboration capability turned out that they acquire significant correlation at 99% reliability level in all variables of IT infra and IT Utilization which are independent variables. In addition, correlation coefficient between each factor is less than 0.8, which proves that the validity of this study judgement has been acquired. The pair with the highest coefficient had 0.628 for IT utilization and technology-accumulating capability. Regression model which can estimate independent variables was used in this study under the hypothesis that there is linear relation between independent variables and dependent variables so as to identify CAI capability's impact factors on R&D. The total explanations of IT infra among CAI capability for independent variables such as organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability are 10.3%, 7%, 11.9%, 30.9%, and 10.5% respectively. IT Utilization exposes comprehensively low explanatory capability with 12.4%, 5.9%, 11.1%, 38.9%, and 13.4% for organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability respectively. However, both factors of independent variables expose very high explanatory capability relatively for technology-accumulating capability among independent variable. Regression formula which is comprised of independent variables and dependent variables are all significant (P<0.005). The suitability of regression model seems high. When the results of test for dependent variables and independent variables are estimated, the hypothesis of 10 different factors appeared all significant in regression analysis model coefficient (P<0.01) which is estimated to affect in the hypothesis. As a result of liner regression analysis between two independent variables drawn by influence factor analysis for R&D capability and R&D capability. IT infra and IT Utilization which are CAI capability factors has positive correlation to organization capability, process capability, human resources capability, technology-accumulating capability, and collaboration capability with inside and outside which are dependent variables, R&D capability factors. It was identified as a significant factor which affects R&D capability. However, considering adjustable variables, a big gap is found, compared to entire company. First of all, in case of partner companies with big companies, in IT infra as CAI capability, organization capability, process capability, human resources capability, and technology capability out of R&D capacities seems to have positive correlation. However, collaboration capability appeared insignificance. IT utilization which is a CAI capability factor seemed to have positive relation to organization capability, process capability, human resources capability, and internal/external collaboration capability just as those of entire companies. Next, by analyzing independent types of SMEs as an adjustable variable, very different results were found from those of entire companies or partner companies with big companies. First of all, all factors in IT infra except technology-accumulating capability were rejected. IT utilization was rejected except technology-accumulating capability and collaboration capability. Comprehending the above adjustable variables, the following results were drawn in this study. First, in case of big companies or partner companies with big companies, IT infra and IT utilization affect improving R&D Capabilities positively. It was because most of big companies encourage innovation by using IT utilization and IT infra building over certain level to their partner companies. Second, in all companies, IT infra and IT utilization as CAI capability affect improving technology-accumulating capability positively at least as R&D capability factor. The most of factor explanation is low at around 10%. However, technology-accumulating capability is rather high around 25.6% to 38.4%. It was found that CAI capability contributes to technology-accumulating capability highly. Companies shouldn't consider IT infra and IT utilization as a simple product developing tool in R&D section. However, they have to consider to use them as a management innovating strategy tool which proceeds entire-company management innovation centered in new product development. Not only the improvement of technology-accumulating capability in department of R&D. Centered in new product development, it has to be used as original management innovative strategy which proceeds entire company management innovation. It suggests that it can be a method to improve technology-accumulating capability in R&D section and Dynamic capability to acquire sustainable competitive advantage.

• Journal of Intelligence and Information Systems
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• v.27 no.1
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• pp.191-207
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• 2021

Up to this day, mobile communications have evolved rapidly over the decades, mainly focusing on speed-up to meet the growing data demands of 2G to 5G. And with the start of the 5G era, efforts are being made to provide such various services to customers, as IoT, V2X, robots, artificial intelligence, augmented virtual reality, and smart cities, which are expected to change the environment of our lives and industries as a whole. In a bid to provide those services, on top of high speed data, reduced latency and reliability are critical for real-time services. Thus, 5G has paved the way for service delivery through maximum speed of 20Gbps, a delay of 1ms, and a connecting device of 106/㎢ In particular, in intelligent traffic control systems and services using various vehicle-based Vehicle to X (V2X), such as traffic control, in addition to high-speed data speed, reduction of delay and reliability for real-time services are very important. 5G communication uses high frequencies of 3.5Ghz and 28Ghz. These high-frequency waves can go with high-speed thanks to their straightness while their short wavelength and small diffraction angle limit their reach to distance and prevent them from penetrating walls, causing restrictions on their use indoors. Therefore, under existing networks it's difficult to overcome these constraints. The underlying centralized SDN also has a limited capability in offering delay-sensitive services because communication with many nodes creates overload in its processing. Basically, SDN, which means a structure that separates signals from the control plane from packets in the data plane, requires control of the delay-related tree structure available in the event of an emergency during autonomous driving. In these scenarios, the network architecture that handles in-vehicle information is a major variable of delay. Since SDNs in general centralized structures are difficult to meet the desired delay level, studies on the optimal size of SDNs for information processing should be conducted. Thus, SDNs need to be separated on a certain scale and construct a new type of network, which can efficiently respond to dynamically changing traffic and provide high-quality, flexible services. Moreover, the structure of these networks is closely related to ultra-low latency, high confidence, and hyper-connectivity and should be based on a new form of split SDN rather than an existing centralized SDN structure, even in the case of the worst condition. And in these SDN structural networks, where automobiles pass through small 5G cells very quickly, the information change cycle, round trip delay (RTD), and the data processing time of SDN are highly correlated with the delay. Of these, RDT is not a significant factor because it has sufficient speed and less than 1 ms of delay, but the information change cycle and data processing time of SDN are factors that greatly affect the delay. Especially, in an emergency of self-driving environment linked to an ITS(Intelligent Traffic System) that requires low latency and high reliability, information should be transmitted and processed very quickly. That is a case in point where delay plays a very sensitive role. In this paper, we study the SDN architecture in emergencies during autonomous driving and conduct analysis through simulation of the correlation with the cell layer in which the vehicle should request relevant information according to the information flow. For simulation: As the Data Rate of 5G is high enough, we can assume the information for neighbor vehicle support to the car without errors. Furthermore, we assumed 5G small cells within 50 ~ 250 m in cell radius, and the maximum speed of the vehicle was considered as a 30km ~ 200 km/hour in order to examine the network architecture to minimize the delay.

• The Journal of Korean Academic Society of Nursing Education
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• v.4 no.2
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• pp.236-248
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• 1998

This survey study was attempted for two purposes : 1) to grasp Korea National Open University(KNOU) students' changing aspects for their education need through comparison analyses with 1996 data ; 2) to establish foundation of the systematic network formation by investgating students' opinion about network framework. Among randomly assigned 4,500 students, 1,505 KNOU nursing students who allowed to participate in the study completed the questionnaires. The data were collected by mail. For the comparison 1996 data were also used. The data were analyzed using descriptive statistics, chi-square test, and t-test. Results of this study were as follows 1. The admission purposes of the KNOU nursing students were 'in order to get a bachelor's degree (70.7%)', 'to do studying and working simultaneously(43.0%)', or 'to be admitted for the graduate school (41%)' etc. Comparing the admission purposes by age, the investigator found 4 items which are 'small amount of tuition', 'graduate school admission', 'aspiration for the university', 'promotion or commencement of work' showed statistically significant differences. These 4 items were also found to show significant differences by marital status. 2. In relation to the learning media, the study showed most students(74%) got effective informations from the school newspaper(36.5%) or peer group(37.7%). The result showed that few students (0.7%) used the computer for communication. The research indicated that KNOU nursing students have tendency to rely on printed materials more than on broadcasting media. This is almost the same result as that of 1996. 3. The results revealed that 12.4% of the respondents had ever experienced unregistration or temporary withdrawal. The most common reason for the unregistration was 'due to family affairs or their job (71.3%)'. There were no change for this aspects with 1996. 4. As for the professors-students network formation. The result revealed that 38.5% students among respondents had heard of the network formation. 78.7% of respondents, however, positively responed that they would willingly participate in the networking if it is made. Especially the students showed much interest in 'the improvement for the understanding of study' and 'strengthening of the relations between professors and students'.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.577-584
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• 2007

Adipocyte-specific secretory factor(ADSF)/resistin, an hormone, is a small cysteine-rich protein secreted from adipose tissue and ADSF/resistin has been implicated in modulating adipogenesis in human and rodents. Although the exact role of ADSF/resistin in bovine has not been identified, it may have directly or indirectly involved in adipocyte differentiation. The objective of this study was to investigate its DNA polymorphism associated with carcass traits in Korean Native Cattle(Hanwoo). To investigate DNA polymorphism in Hanwoo ADSF/resistin gene, blood samples were taken from 295 Hanwoo steers belonging to progeny testing at Hanwoo Improvement Center in Korea. Seven single nucleotide polymorphisms(SNPs) were found in intron regions but not in any other regions including promoter (1.7kb) and 4 exons. The highest frequency among SNPs was C186A(0.16/0.84) following G964A (0.156/0.884). The significant correlation(P<0.05) between the SNPs and economic traits was found on 764Ains associated with marbling but not from any other SNPs determined.  A computer simulation was also conducted to assess the efficiency of marker assisted selection(MAS) versus the conventional breeding scheme.  Results revealed that MAS was more efficient as a breeding tool compared to the conventional. In conclusion, ADSF/Resistin gene is one of candidate genes to evaluate the quality, especially marbling score, in Hanwoo.

• Korean Journal of Applied Biomechanics
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• v.26 no.2
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• pp.175-181
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• 2016

Objective: The aim of this study was to investigate age-related changes of multi-finger synergy during a constant force production task with and without an additional mechanical constraint. Method: Fourteen elderly subjects (age: $78.50{\pm}4.63yrs$, height: $157.29{\pm}8.97cm$, weight: $65.13{\pm}6.93kg$) and 14 young subjects (age: $21.13{\pm}1.35yrs$, height: $171.57{\pm}8.43cm$, weight: $70.29{\pm}16.77kg$) participated in this study. The subjects were asked to place their index and middle fingers on two force transducers fixed on a small non-moving teeterboard and produce 10 N by pressing the sensors while watching force feedback on a computer screen under the no additional constraint condition (NAC). The subjects also performed the same task with an additional mechanical constraint (AC) where the subjects were asked to balance a teeterboard that could be rotated by finger forces. An uncontrolled manifold approach was used to calculate within-trial and between-trial multi-finger synergy indices, variance in uncontrolled subspace ($V_{UCM}$), and variance in subspace orthogonal to UCM subspace ($V_{ORT}$). Two-way repeated measured ANOVA was performed with the within-factor of task condition (with and without an additional constraint) and the between factor of groups (elderly and young). Results: The elderly group showed significantly increased within-trial $V_{ORT}$ in AC compared with NAC (p < .05) while the young group showed no significant difference between AC and NAC. There was no significant group difference for within-trial $V_{UCM}$. Between-trial $V_{ORT}$ remained unchanged between groups and conditions. However, between-trial $V_{UCM}$ for the elderly group significantly decreased in AC as compared to NAC, along with no significant difference for the young group. For multi-finger synergy, there was no significant group difference of within-trial synergy. However, between-trial synergy for the elderly group significantly decreased in AC as compared to NAC (p < .05). Conclusion: Our results indicate that aging decreased consistency (i.e., ability to perform the task on a moment-to-moment basis) with an additional mechanical constraint. In addition, aging was associated with decreased multi-finger synergy on a trial-to-trial basis.

• Journal of Korean Medicine Rehabilitation
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• v.24 no.1
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• pp.65-76
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• 2014

Objectives The purpose of this study is to investigate the corelation between traffic accident severity and treatment period and cost by traffic accident. Methods Outpatients who visited Jaseng Korean medicine hospital traffic accident clinic were investigated by hospital computer system about period and cost of treatment. And we requested for repair cost of car, a sort of car groups and agreement date with car insurance company to insurance company. Therefore we could analysis statistical correlation of traffic accident severity (repair cost of car) with period of treatment, cost of treatment, number of treatment in same sort of car groups. For statistics, we used SPSS version 18.0 for windows. Results A significant positive correlation was found between traffic accident severity (repair cost of car) with repair cost of car, cost of treatment and number of treatment in semi-midsize car, midsize car group. But, any significant correlation wasn't found between traffic accident severity (repair cost of car) with repair cost of car, cost of treatment and number of treatment in small car, full-sized car group. In SUV (sport utility vehicle) car group some significant correlation was found, but it isn't between traffic accident severity (repair cost of car) with repair cost of car, cost of treatment and number of treatment. Conclusions It was found that traffic accident severity (repair cost of car) had an effect on cost of car, cost of treatment and number of treatment by statistical analysis. But, it was also suggested strongly that other factors like a cost of car and ages had an effect on them.

• Journal of The Korean Association of Information Education
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• v.24 no.1
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• pp.21-28
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• 2020

Technological advancements such as artificial intelligence, robots, and big data are revolutionizing the entire society. In this paper, we analyzed preliminary teachers' daily internet/gaming/smartphone habit and the difference between preference factors in gender and diagnosis group in the situation of ethical dilemma in driverless cars. The result shows most of the male students are in high risk group of daily internet/gaming usage, and male students tend to be more immersed in games compared to female students, which negatively affects their daily lives. Students who have at least one of the daily internet/gaming/smartphone habits are more likely to be classified as high-risk group in all three of daily internet/gaming/smartphone habit. Fortunately, the students perceived themselves addicted and wanted change their habits. An analysis by a moral machine of these students tells that there is no significant difference in preference between male and female students and among diagnosis groups. However, specifically in the ethical dilemma of driverless cars, all the groups of male, female, normal, high-risk showed they have priority in pedestrians over drivers, a large number of people over small, and people who obey traffic rules over who do not. The tendency was pronounced in female group and high-risk students prioritized people who are older and in lower social status.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.283-288
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• 2012

3D is the one of the current world in the spotlight as part of the future earnings of the business sector. Existing flat 2D and stereoscopic 3D to change the 3D shape and texture make walking along the dimension of the real world and the virtual reality world by making it feel contemporary reality of coexistence good show. 3D for the interest of the people has been spreading throughout the movie which is based on a 3D Avata. 3D TV market of the current conglomerate of changes in the market pioneer in the 3D market, further leap into the era of the upgrade was. At the same time, however, the modern man of the world, if becoming a necessity in the smartphone craze new innovation in the IT market mobile phone market and also has made. A small computer called a smartphone enough, the ripple velocity and the aftermath of the innovation of the telephone, the Internet as much as to leave many issues. Smartphone smart phone is a mobile phone that can be several functions. The current iPhone, Android. In addition to a large number of Windows Phone smartphones are released. Above the overall prospects of the future and a business service model for 3D facial expression as input avatar virtual 3D character on camera on your smartphone camera to recognize a user's emotional expressions on the face of the person is able to synthetic synthesized avatars in real-time to other mobile phone users matching, transmission, and be able to communicate in real-time sensibility fused video communication services to the development of applications.