• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1663-1674
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• 2017

This paper deals with the robust speed regulation of a surface-mounted permanent magnet synchronous motor (SPMSM) that is subject to parametric uncertainties and external disturbances. The proposed approach retains a conventional cascade control configuration composed of an outer-loop speed control module and inner-loop current control modules. Baseline proportional-integral (PI) controllers are designed for nominal modular systems without accounting for the uncertainties to set a desired control performance of the closed-loop system. After studied in both frequency and time domains, a reduced-order proportional-integral observer (PIO), as a modular disturbance observer, is incorporated with each control module to maintain the ideal performance of the modules. Theoretical analysis confirms the desired performance recovery of the augmented system with modular PIOs to the nominal system. Comparative computer simulations and experimental results validate the proposed cascade control method for SPMSM speed regulation.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.293-297
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• 2008

동영상 서비스의 공급과 수요의 증가로 많은 양과 종류의 동영상에 접근을 제공하기 위한 브라우징과 검색이 보다 중요해지고 있다. RSVP와 사용자 태그의 개념을 이용한 동영상 브라우징인 'Rapid Browsing'은 사용자가 원하는 동영상 내용에 보다 효율적으로 접근할 수 있도록 한다. 이 방법은 바로 원하는 장면이 있는지 찾아볼 수 있으므로 검색시간을 단축함은 물론 어떤 내용이 있는지 빠르게 알아낼 수 있다. 또한 사용자의 시간태그를 기반으로 미리보기를 제공하기 때문에 하이라이트 부분을 먼저 감상할 수 있고 이로써 내용을 기반으로 한 검색이 가능해지며 빠르게 댓글을 통한 사용자들끼리의 커뮤니케이션 효과가 있다는 장점이 있다.

• Journal of Communications and Networks
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• v.2 no.1
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• pp.18-34
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• 2000

The evolution of mobile communications is inducting several new issues belonging to the system engineering disciplines. this paper tires to underline some of the most important problems staring room the novel requirements and the application characteristics expected for Third Generation Mobile System. Based on these new service peculiarities. the radio resource control and the architectural solutions to be chosen for the Mobile core network are becoming key issues to be investigated for the forthcoming configurations. Particularly. the service acceptance control and the perspective of integration with the IP (internet Protocol) context are of great importance for the definition of the radio control functions and the specification of the switching and nobility control features respectively．The paper presents some basic considerations on the cellular planning issues arising in W-CDMA ( wideband -code division Multiple access) systems. by underlying the most significant innovative elements that are to be introduced in the planning process form the mobile operator viewpoint..

• Journal of the Korean Society for Precision Engineering
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• v.15 no.4
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• pp.36-43
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• 1998

We experimented turning SCM440, called difficult-to-cut materials in general, using tungsten carbon tool(PIO) in order to elevate machinability by a new cutting method. The cutting tool designed and made to study was cooled to -17$0^{\circ}C$ in about 1 minute by liquid nitrogen. Then, we operated cryogenic cutting by cooling tool with liquid nitrogen and stuided the effect about cutting force, chip thickness, surface roughness, behavior of tool wear and cutting temperature. In addition, we investigated the possibility that sur face roughness of workpiece can be predicted analyzing cutting characteristics.

• Archives of Reconstructive Microsurgery
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• v.12 no.2
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• pp.99-104
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• 2003

Liposuction is a useful method for debulking free flap. Recently, ultrasound assisted liposuction(UAL) has been reported to have many advantages over conventional suction-assisted lipectomy. We applied the UAL to debulk free fasciocutaneous flap of the forehead and lower extremities. The result was satisfactory and there was no significant complications worth noting. Although the cost can be expensive, it has many advantages such as less blood loss, larger amount of fat aspirate and better skin contraction. We can conclude that UAL can be a useful alternative method to debulk free fasciocutaneous flap.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.286-286
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• 2000

We consider a negative unity feedback control system in which Che PIO, PI, PD or P controller and a transfer function having only poles are in cascade, We define the notion of the structural polynomial which means that there exists a subdomain of the coefficient space in which the polynomial is Hurwitz (left half plane stable) polynomial. We obtain the necessary and sufficient condition of the structure of the transfer function of which the characteristic polynomial is a structural polynomial, In addition, this paper present another necessary and sufficient condition for the existence of a constant gain controller with which the characteristic polynomial is structurally stable, For the structurally stabilizable P controller, it is allowed that the transfer function may not to all pole plants.

• Archives of Reconstructive Microsurgery
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• v.11 no.2
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• pp.162-166
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• 2002

The anterolateral thigh free flap was first reported by Song et al. in 1984 as a fasciocutaneous flap based on septocutaneous or musculocutaneous perforators of the lateral femoral circumflex vessel. It only becomes popular recently through confirmation of additional anatomy. For reconstruction of Achilles area defect, a thin flap is required to improve aesthetic and functional results. The anterolateral thigh free flap is relatively thin and can provide large skin area. It can be a useful option for reconstruction of Achilles area defect based on these characters. Since March 2002, we have successfully transferred 4 anterolateral thigh free flaps to reconstruct Achilles area defects and have attained good range of motion in this region. The anterolateral thigh free flap has many advantages and can be used for the reconstruction of Achilles tendon area defect.

• Journal of Internet Computing and Services
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• v.14 no.5
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• pp.77-85
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• 2013

This paper proposes a closeness centrality analysis algorithm for workflow-supported social networks that represent the collaborative relationships among the performers who are involved in a specific workflow model. The proposed algorithm uses the social network analysis techniques, particularly closeness centrality equations, to analyze the closeness centrality of the workflow-supported social network. Additionally, through an example we try to verify the accuracy and appropriateness of the proposed algorithm.

• Archives of Reconstructive Microsurgery
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• v.13 no.1
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• pp.82-85
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• 2004

Flap monitoring is important for flap salvage. Although there are many methods to observe the flap, practical methods mostly used are subjective methods. Recording flap surface temperature is one of the objective methods of flap monitoring. We used an infra-red thermometer to simplify monitoring of the flap temperature. 60 groin flaps of SD rats are used in the experiment. Artificial arterial or venous insufficiency was made and the surface temperature was checked and compared with body temperature. In the results, the temperature of the arterial clamped flaps was lower than that of body and the mean difference was $0.3^{\circ}C$ after 20 minutes of clamping. In the vein-clamped flaps, the mean decrease was $0.4^{\circ}C$ after 30 minutes of clamping. The all difference of the temperature between the flaps and body was statistically significant. Our results suggest that flap monitoring by infra-red thermometer is simple, useful and helpful to evaluate the flap status.

• YAKHAK HOEJI
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• v.33 no.2
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• pp.73-79
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• 1989

One hundred and sixteen strains of E. coli isolated from drainage in Seoul city in 1987 and 104 strains of E. coli isolated from stools of domestic animals in suburb of Seoul in 1987 were examined for susceptibilities to 10 antimicrobial agents by the agar dilution method. The susceptibilities of the two groups to each antimicrobial agent were compared and correlations in the antimicrobial susceptibility of the 220 strains of E. coli among the 10 antimicrobial agents were also analyzed. The frequency of resistance strains was highest to tetracycline with 77%, and followed by chloramphenicol, streptomycin, ampicillin, kanamycin and cephalosporin in the descreasing order, tanging from 62% to 10%. Strains resistant to tobramycin, nalidixic acid, gentamicin and amikacin occupied 3 strains, 2 strains, 2 strains and 1 strain respectively.