• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.3
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• pp.440-448
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• 2021

This paper presents problems of network technology in smart grid and implements a blockchain-based LoRa multi-hop network to solve them. Since some smart grid applications are operated in harsh environments, it is difficult to establish communication infrastructure. We propose a LoRa network with multi-hop using the Flooding routing protocol. Smart grid environment composes an independent network using various power grid protocols depending on the application. Since this has a problem that an independent infrastructure must be established for each network, a single gateway device supports multiple power grid protocols to implement a method for network integration. Lastly, the author applied Hyperledger-based blockchain to the LoRa network to ensure the integrity of data in a smart grid environment, and strengthened security by physically distributing it. After constructing the three suggestions on the actual test bed, we confirmed that the network operates normally through experiments.

• Journal of the Korean Arthroscopy Society
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• v.11 no.2
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• pp.104-110
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• 2007

Purpose: The purpose of this study is comparison of clinical outcomes in ACL reconstruction between auto-hamstring tendon and allo-tibialis anterior tendon. Materials and Methods: In this prospective study, we included 60 subjects who underwent ACL reconstruction using 30 hamstring autograft(mainly, national health insurance) and 30 tibialis anterior allograft(including MVA and industrial injuries) between May 2003 and June 2005 by a single surgeon, with a minimum follow-up of 12 months. Outcome measurements were the range of motion, the Lachman test, the IKDC score, the Lysholm score, KT-1000 arthrometer and one-leg hop test. Results: For all the cases, the range of motion was above 135 degrees. The Lachman test, KT-1000 arthrometer and one-leg hop test showed no significant difference between two groups. The IKDC score of auto-hamstring group($87.840{\pm}2.106$) was significantly higher than that of allo-tibialis anterior group($85.273{\pm}2.782$). The Lysholm score of auto-hamstring group($88.067{\pm}2.586$) was also significantly higher than that of allo-tibialis anterior group($85.300{\pm}3.030$). Conclusion: The results of ACL reconstruction using the auto-hamstring tendon and allo-tibialis anterior tendon showed no significant difference in objective items but auto-hamstring group showed better results in subjective scoring. This difference may result from individual factors such as economic problem, secondary gain.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.1
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• pp.100-114
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• 2015

This paper deploys optimization techniques to obtain the optimum hull form of KSUEZMAX at the conditions of full-load draft and design speed. The processes have been carried out using a RaPID-HOP program. The bow and the stern hull-forms are optimized separately without altering neither, and the resulting versions of the two are then combined. Objective functions are the minimum values of wave-making and viscous pressure resistance coefficients for the bow and stern. Parametric modification functions for the bow hull-form variation are SAC shape, section shape (U-V type, DLWL type), bulb shape (bulb height and size); and those for the stern are SAC and section shape (U-V type, DLWL type). WAVIS version 1.3 code is used for the potential and the viscous-flow solver. Prior to the optimization, a parametric study has been conducted to observe the effects of design parameters on the objective functions. SQP has been applied for the optimization algorithm. The model tests have been conducted at a towing tank to evaluate the resistance performance of the optimized hull-form. It has been noted that the optimized hull-form brings 2.4% and 6.8% reduction in total and residual resistance coefficients compared to those of the original hull-form. The propulsive efficiency increases by 2.0% and the delivered power is reduced 3.7%, whereas the propeller rotating speed increases slightly by 0.41 rpm.

• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.181-199
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• 2000

In this paper, we implemented and tested MPOA(MutiProtocol Over ATM) standardized in ATM Forum, which provides service for various layer 3 protocols as well as legacy LAN applications over ATM networks. The functions of MPCs(MPOA Clients) and MPSs(MPOA Servers) which are the components in MPOA systems are implemented. MPCs are located at the edge device and MPOA hosts and MPSs exist in routers. The implemented MPCs have the functions such as exchances of primitives between an LEC(LAN Emulation Client) and an MPC, management and maintenance of Egress/Ingress cache, default transmission through LECs and shortcut transmission. Assuming that routing, convergence and NHRP(Next Hop Resolution Protocol) functions exist in routers, the implemented MPSs have the functions such as exchanges of primitives between an LEC and an MPC, conversion and exchanges of frames between MPOA and NHRP, and management and maintenance of Egress/Ingress cache. All of the possible scenarios are made up to test whether they run correctly. The implemented system is tested by simulation according to the scenarios.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7A
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• pp.715-724
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• 2010

K-water has used satellite networks for 12 years for hydrological observation in various parts such as remote data acquisition and providing information including flood forecasting. It is the time to replace equipments according to long-term use of the system. A pilot system for high speed satellite networks is implemented by seven terminals, three 2-hops and 1 hub in Ku-Band bandwidth by using VSAT. According to the result for the performance test on the system, the result fot all items, including Link Budget designed meets performance levels.

• Journal of the Korea Fashion and Costume Design Association
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• v.6 no.3
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• pp.31-43
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• 2004

The purpose of this study is to provide basic data on the propriety of the ready-to-made garment sizes of the boys aged between 10 and 11. The data were collected from 315 boys in the capital area. They were surveyed during the period of April, 2004. Data analysis has been performed through descriptive statistics, $x^2$-test, t-test, ANOVA and Duncan test using SPSS ver.10. The results of the analysis are as follows. According to the result of investigating the favorite fashion style of boys, most boys aged between 10 and 11 preferred casual style(jean pants & T-shirts). Boys of age 10 preferred formal style and 11-year-old boys tend to prefer hip-hop style. When boys buy garments, boys aged between 10 and 11 were influenced by their mother or family. The store in which 10-year-old boys purchased their garments was either a children's or a sports wear store, and boys of 11 age prefer young casual wear store. The highest factors of dissatisfaction on buying garments were price and size. According to the result of evaluating fitting problems, the highest degree of dissatisfaction upon proper fitness upper-arm circumference, waist circumference and pants length.

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.258-262
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• 2009

A Practical application of environmental monitoring system based on wireless sensor node network with the core of embedded system STR711FR2 microprocessor is presented in the paper. The adaptable and classifiable wireless sensor node network is used to achieve the data acquisition and multi-hop wireless communication of parameters of the monitoring base station environment including repeaters. The structure of the system is proposed and the hardware architecture of the system is designed, and the system operating procedures is proposed. As a result of field test, designed hardware platform operated with 50kbps bit rate and 5MHz channel spacing at 2040Hz. The wireless monitoring system can be managed and swiftly retreated without support of base station environmental monitoring.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.141-150
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• 2013

Simulation is an important technique to test and verify routing protocol correctness. However, simulation does not guarantee that the protocol works expectedly on a real world environment because it needs to rely on assumptions and simplified properties such as radio characteristics and effects of geographical constraints that may not reflect the real world networking environments. Therefore, a real world experiments are necessary to gain a practical insight into the actual performance of ad hoc networks. In this paper, we build a test-bed to evaluate multi-hop ad hoc networks for high speed video streaming inside a building using AODV-UU routing protocol. Our observation indicates that the considered ad hoc network can provide a sufficient performance for a low rate streaming data in terms of throughput, PDR (Packet delivery ratio) and the average delay.

• The Korean Fashion and Textile Research Journal
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• v.16 no.3
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• pp.354-365
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• 2014

This study investigates the positioning of emotional language imagesin popular music genres for developing textile print design ideas. Auditory and synaesthetic imagery were employed to deduct emotional language imageries from popular music genres and analyze differences in emotional language imageries according to popular music genres. Six genres of popular music were selected as stimulus and a survey was conducted to analyze emotional language imagery differences and similarities depending on popular music genres. The results of this study were: The results of the factor analysis and the reliability test on emotional language imagery showed factorial structures that include Lyrical-Feminine, Intense-Masculine, Euphoric-Active, Gloomy-Melancholy, Abstruse-Sophisticated, and Addictive-Continuous. The results of the mean scores of emotional language imagery of each popular music genre showed that respondents tended to perceive that ballad and new age music are similar and hip-hop & rap, dance, and metal-rock are similar. Based on the multidimensional scaling analysis, new age positioned Lyrical-Feminine, metal-rock positioned Intense-Masculine, dance music positioned Euphoric-Active, and ballad positioned Gloomy-Melancholy. This study provides elementary resources to inspire innovative textile prints designed through different characteristics of emotional language imagery according to each popular music genre.

• Journal of agricultural medicine and community health
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• v.39 no.1
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• pp.14-24
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• 2014

Objectives: The purpose of this study was to estimate the prevalence of food allergies and find out food allergens. Methods: Questionnaires were completed by 2,415 subjects in D city, among whom 452 subjects believed that they had food allergy. Skin prick tests were performed on these subjects. The data were analyzed using SAS Version 9.0 and ${\chi}^2$-test. In addition, several recent studies were reviewed. Results: The prevalence rate of food allergic symptoms was 25.6% in males and 25.8% in females, respectively. The positive rate of skin prick tests among those who were allergic to any of 14 food items was 21.4% in males and 14.7% in females(p=0.018). Therefore, it was estimated that the prevalence rate of food allergy was 5.0% in males and 3.6% in females. It was shown that the major food allergens were hop, shrimp, lobster, oyster and egg(whole) in males, and egg(whole), hop, oyster, and pork in females, respectively. The prevalence in recent studies ranged from 1 to 35%. Major food allergens were milk, egg, nuts, fish, shellfish crustacean and fruits/vegetables. Conclusions: In order to provide effective care for food allergy, it is essential to find out the prevalence of food allergies and food allergens.