• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.633-638
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• 2003

In this paper, we propose a humanoid active audition system which detects the direction of sound and performs speech recognition using just three microphones. Compared with previous researches, this system which has simpler algorithm, fewer microphones and better amplifier shows better performance. In order to verify our system's performance, we install the proposed active audition system to the home service robot, called Hombot II, which has been developed at the KIST (Korea Institute of Science and Technology), thus we confirm excellent performance by experimental results

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.3
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• pp.327-335
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• 2011

A study on the RCS of a self-manufactured active transponder, which has a manually adjustable RCS, for SAR(Synthetic Aperture Radar) external calibration and image analysis at X-band is presented in this paper. The RCS of the active transponder was comparably analyzed using the lab-test and the COSMO-SkyMed SAR system, and also precisely analyzed the difference between the adjusted and estimated RCSs. A maximum RCS of the designed and manufactured active transponder is 60 dBsm. The active transponders with 60 dBsm and the adjusted RCS of 40 dBsm were measured using the single target calibration technique(STCT) and 2D target scanning technique(2DTST). And the extracted RCS using power-spill integration technique in a SAR image was compared with the measured RCS of active transponder. The comparison results show that the measured and extracted RCSs are 59.7 dBsm, 40.2 dBsm and 57.3 dBsm, 39.2 dBsm, respectively.

• Journal of the Korean Society of Clothing and Textiles
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• v.39 no.5
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• pp.745-754
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• 2015

This study analyzed Korean middle-aged men's fashionable styles according to ageless trends as their representative characteristic and deriving their special features from men's magazines. Literature and case studies were conducted together. The research findings are as follows. First, it showed uniformity, conformity, passive clothing selection and consumption in 1990s as characteristics of middle-aged men's wear by period. However, clothing became an expressive way to pursue individuality and an ageless trend gradually, and middle-aged men positioned themselves as subjects of a consumer market for men's wear after 2010 through active clothing selection and consumption. Second, along with a trend change preferring a comfortable and active to formal atmosphere, it showed that casual style became diversified and segmented gradually in Korean middle-aged men's ageless trend and fashionable style. Third, as for formative characteristic changes in middle-aged men's fashionable style by period, it contained a slim silhouette, bright and splendid colors and patterns, increase of light, active and functional materials, generalization of casual items and pursuit of individuality by various mix & match styles. Fourth, in Korean men's ageless trend and changing fashionable style, four kinds of special characteristics were derived that included a change of the traditional clothing symbolism, weakened conformity & pursuit of personality, obscured boundaries between age and wearing style, and active embracing of a trend.

• Macromolecular Research
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• v.17 no.11
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• pp.912-918
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• 2009

An optically active diacid containing the L-histidine moiety was prepared by reacting pyromellitic dianhydride (1,2,4,5-benzenetetracarboxylic acid 1,2,4,5-dianhydride) 1 with L-histidine 2 in acetic acid, and was polymerized with several aromatic diamines 5a-g to obtain a new series of optically active poly(amide-imide)s (PAIs) using two different methods, such as direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone (NMP)/triphenyl phosphite (TPP)/calcium chloride ($CaCl_2$)/pyridine (Py) and direct polycondensation in a tosyl chloride (TsCl)/pyridine (Py)/N,N-dimethylformamide (DMF) system as a condensation agent. The resulting new polymers 6a-g with inherent viscosity was obtained in good yield. The polymers were readily soluble in polar organic solvents, such as N,N-dimethyacetamide (DMAc), N,N-dimethyformamide (DMF), and dimethyl sulfoxide (DMSO). The obtained polymers were characterized by FTIR, specific rotation, elemental analysis as well as $^1$H-NMR spectroscopy and gel permeation chromatography (GPC). The thermal stability of the resulting PAIs was evaluated with thermogravimetric analysis techniques under a nitrogen atmosphere.

• Advances in nano research
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• v.9 no.2
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• pp.113-122
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• 2020

Surface-Enhanced Raman Scattering (SERS) spectroscopy is a multifaceted surface sensitive methodology which exploits spectroscopy-based analysis for various applications. This technique is based on the massive amplification of Raman signals which were feeble previously in order to use them for appropriate identification at qualitative and quantitative in chemical as well as biological systems. This novel powerful technique can be utilized to identify pathogens such as bacteria and viruses. As far as SERS is concerned, one of the most studied problems has been functionalization of SERS active substrate. Metal colloids and nanostructures or microstructures synthesized using noble metals such as Au, Ag and Cu are considered to be SERS active. Silver and gold are extensively used as SERS active substrates due to chemical inertness and stability in air compare to copper. However, use of Cu as a suitable alternative has been taken into account as it is cheap. Herein, we have synthesized air-stable copper microstructures/nanostructures by chemical, electrochemical and microwave-assisted methods. In this paper, we have also discussed the use of as synthesized copper micro/nanostructures as inexpensive yet effective SERS active substrates for the fast identification of micro-organisms like Staphylococcus aureus and Escherichia coli.

• Korean Journal of Human Ecology
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• v.13 no.6
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• pp.861-874
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• 2004

The goal of this study is to investigate the relationship between maternal rearing behavior characteristics and elementary school children's Internet use, and to utilize the results as the basic data to develop a program, in which parents learn how to educate their children for better use of the Internet. The subjects were 713 children whose grade are in fourth through sixth in an elementary school. Data were obtained with questionnaires. The instruments employed were Children's Internet Use and Addiction, and maternal rearing behavior characteristics-Rational Guidance, Affection, Authoritarian Control, Overprotection, Achievement Encouragement, and Active Involvement-Scales. The data were analyzed with the SPSS program. They were analyzed by Frequency, Percentage, ANOVA, Duncan's test, and Pearson correlation. The results of this study are as follows: First, 30.2% of the subjects has used Internet for more than three years. 55.6% of the subjects spend less than an hour per day in using the Internet. The two major types of Internet use were playing games(49.9%) and sending e-mails(25.4%). The main reason for playing Internet games was escape from stress(34.7%). 34.5% of the subjects also said that their parents usually encourage them to use the Internet. Second, maternal affection, authoritarian control, and active involvement were significantly different in the types of Internet use. Maternal authoritarian control and overprotection were significantly different in the reasons of doing Internet game. The rational guidance and active involvement of mothers were correlated negatively with children's Internet using time, but their authoritarian control and overprotection were correlated positively with children's Internet using time. Maternal overprotection was correlated positively with parents' encouragement level in the Internet use. Third, the rational guidance, affection, and active involvement of mothers were correlated negatively with children's Internet addiction. In the other hand, maternal authoritarian control and overprotection were correlated positively with children's Internet addiction. Lastly, children's Internet addiction was significantly different by the types of Internet Use and the reasons for doing internet game. Children's Internet using time was correlated positively with children's Internet addiction.

• Journal of Industrial Technology
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• v.24 no.B
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• pp.207-214
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• 2004

An active stick which supplies force feedback to the operator is developed in this study. A mathematical model of the active stick is derived, and compared with the experimental result. It turns out that the frictional torque due to the mechanical contacts of several parts of the stick is one of the major barriers to achieve high precision operation of the stick. The frictional effect of the stick is cancelled out by using a friction observer. The efficacy of the friction observer is verified through the numerical simulation. Because of the observer dynamics, there are some limitations in exact recovering the static friction and Stribeck effect. However, the friction observer follows the real friction on the average. It's anticipated that the application of the friction observer to the closed loop control of the active stick improves the performance of the displacement versus force characteristics, which will be proved experimentally in the further study.

• Transactions of The Korea Fluid Power Systems Society
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• v.7 no.4
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• pp.32-38
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• 2010

A semi-active suspension is an automotive technology that controls the vertical movement of the vehicle while the car is driving. The system therefore virtually eliminates body roll and pitch variation in many driving situations including cornering, accelerating, and braking. This technology allows car manufacturers to achieve a higher degree of both ride quality and car handling by keeping the tires perpendicular to the road in corners, allowing for much higher levels of grip and control. An onboard computer detects body movement from sensors located throughout the vehicle and, using data calculated by opportune control techniques, controls the action of the suspension. Semi-active systems can change the viscous damping coefficient of the shock absorber, and do not add energy to the suspension system. Though limited in their intervention (for example, the control force can never have different direction than that of the current speed of the suspension), semi-active suspensions are less expensive to design and consume far less energy. In recent time, the research in semi-active suspensions has continued to advance with respect to their capabilities, narrowing the gap between semi-active and fully active suspension systems. In this paper we are studied the characteristics of vehicle movement during the field test with conventional and semi-active suspension system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.63-64
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• 2011

• ETRI Journal
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• v.30 no.2
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• pp.194-204
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• 2008

The online collection of coarse-grained traffic information, such as the total number of flows, is gaining in importance due to a wide range of applications, such as congestion control and network security. In this paper, we focus on an active queue management scheme called SRED since it estimates the number of active flows and uses the quantity to indicate the level of congestion. However, SRED has several limitations, such as instability in estimating the number of active flows and underestimation of active flows in the presence of non-responsive traffic. We present a Markov model to examine the capability of SRED in estimating the number of flows. We show how the SRED cache hit rate can be used to quantify the number of active flows. We then propose a modified SRED scheme, called hash-based two-level caching (HaTCh), which uses hashing and a two-level caching mechanism to accurately estimate the number of active flows under various workloads. Simulation results indicate that the proposed scheme provides a more accurate estimation of the number of active flows than SRED, stabilizes the estimation with respect to workload fluctuations, and prevents performance degradation by efficiently isolating non-responsive flows.