• Title/Summary/Keyword: IB system

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Development of Simplified Immersed Boundary Method for Analysis of Movable Structures (가동물체형 구조물 해석을 위한 Simplified Immersed Boundary법의 개발)

  • Lee, Kwang-Ho;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.33 no.3
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    • pp.93-100
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    • 2021
  • Since the IB (Immersed Boundary) method, which can perform coupling analysis with objects and fluids having an impermeable boundary of arbitrary shape on a fixed grid system, has been developed, the IB method in various CFD models is increasing. The representative IB methods are the directing-forcing method and the ghost cell method. The directing-forcing type method numerically satisfies the boundary condition from the fluid force calculated at the boundary surface of the structure, and the ghost-cell type method is a computational method that satisfies the boundary condition through interpolation by placing a virtual cell inside the obstacle. These IB methods have a disadvantage in that the computational algorithm is complex. In this study, the simplified immersed boundary (SIB) method enables the analysis of temporary structures on a fixed grid system and is easy to expand to three proposed dimensions. The SIB method proposed in this study is based on a one-field model for immiscible two-phase fluid that assumes that the density function of each phase moves with the center of local mass. In addition, the volume-weighted average method using the density function of the solid was applied to handle moving solid structures, and the CIP method was applied to the advection calculation to prevent numerical diffusion. To examine the analysis performance of the proposed SIB method, a numerical simulation was performed on an object falling to the free water surface. The numerical analysis result reproduced the object falling to the free water surface well.

Research Trends in Propulsion Technology for Divert and Attitude Control System (연속가변 추력제어 추진기술 연구동향)

  • Ha, Dongsung;Lim, Seongtaek
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.353-357
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    • 2017
  • The research trends and major technologies of the divert attitude control system(DACS), which is the core of the anti-missile system, are described. The operating concept and characteristics according to the fuel used are summarized. The characteristics of typical weapon system applying solid(SM3 Block IB/IIA) and liquid(THAAD) fuels were discussed. In the future, it will be necessary to study various types of DACS in the strategic concept of the defense weapon system.

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EO performance of IPS cell on the inorganic films surface using DuoPIGatron ion source (유기박막표면에 DuoPIGatron 이온소스를 이용한 IPS 셀의 전기광학 특성)

  • Kim, Byoung-Yong;Hwang, Jeoung-Yeon;Kim, Sang-Hun;Han, Jung-Min;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.04a
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    • pp.89-90
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    • 2006
  • Electro-optical (EO) characteristics of in-plane switching (IPS) cell on the polyimide surface using obliquely ion beam (IB) exposure as new ion beam (IB) type system (DuoPIGatrion ion source). A good uniform alignment of the nematic liquid crystal (NLC) alignment with the ion beam exposure on the polyimide surface was observed. In addition, it can be achieved the good EO properties of the ion-beam-aligned IPS-cell on poly imide surface ; the stable VT curve in the ion-beam-aligned IPS cell on a poly imide (PI) surface with ion beam exposure using new type IB equipment was obtained. and the fast response time in the ion-beam-aligned IPS cell on a polyimide (PI) surface with ion beam exposure using new type IB equipment was obtained.

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EO performance of TN cell on the inorganic films surface using DuoPIGatron ion source on NDLC thin film (무기박막표면에 DuoPIGatron 이온소스를 이용한 TN-LCD 셀의 전기광학 특성)

  • Kim, Byoung-Yong;Hwang, Jeoung-Yeon;Kim, Sang-Hun;Han, Jung-Min;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.432-433
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    • 2006
  • Electro-optical (EO) characteristics of twisted nematic (TN) - liquid crystal display (LCD) on the NDLC thin film using obliquely ion beam (IB) exposure as new ion beam (IB) type system (DuoPIGatrion ion source). A good uniform alignment of the nematic liquid crystal (NLC) alignment with the ion beam exposure on the NDLC thin film was observed. In addition, it can be achieved the good EO properties of the ion-beam-aligned TN-cell on polyimide surface ; the stable VT curve in the ion-beam-aligned TN cell on the NDLC thin film with ion beam exposure using new type IB equipment was obtained. and the fast response time in the ion-beam-aligned TN cell on the NDLC thin film with ion beam exposure using new type IB equipment was obtained.

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Factors Affecting Hospital Employees' Knowledge Sharing (병원 근로자의 지식공유에 영향을 미치는 요인)

  • Lee, Hyun-Sook;Lee, Hae-Jong;Kim, Young-Hoon
    • Korea Journal of Hospital Management
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    • v.19 no.1
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    • pp.43-53
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    • 2014
  • The objective of this research is to survey of knowledge management in hospitals and to search the factors to impact the knowledge sharing and innovation behavior among employees. The data is collected with hospital employees by questionnaire method. Total number of analysis is 779 cases, and the collected data is analyzed by SEM(structural equation model). The work performance(WP) make influence the innovation behavior(IB) through knowledge sharing(KS) intention. The KS intention and IB are different in sex, age, education, work duration and work level. But, WP is different only in sex. The only personnel and organizational factors to affect KS intention, WP and IB are reciprocity(in personnel factor) and trust(in organization factor). Those factors mean the mental or psychological relationship among employees. So, to make more developed knowledge management in hospitals is to need more personal relationship than any other system management or incentives.

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EFFECT OF LIGHT INTENSITY ON THE POLYMERIZATION RATE OF COMPOSITE RESIN USING REAL-TIME MEASUREMENT OF VOLUMETRIC CHANCE (광조사 강도가 복합레진의 중합반응속도에 미치는 영향에 관한 실시간 체적측정법을 이용한 연구)

  • La, Sung-Ho;Lee, In-Bog;Kim, Chang-Keun;Cho, Byeong-Hoon;Lee, Kwang-Won;Son, Ho-Hyun
    • Restorative Dentistry and Endodontics
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    • v.27 no.2
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    • pp.135-141
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    • 2002
  • Objectives : The aim of this study is to evaluate the effect of light intensity variation on the polymerization rate of composite resin using IB system (the experimental equipment designed by Dr. IB Lee) by which real-time volumetric change of composite can be measured. Methods : Three commercial composite resins [Z100(Z1), AeliteFil(AF), SureFil(SF)] were photopolymerized with Variable Intensity Polymerizer unit (Bisco, U.S.A.) under the variable light intensity (75/150/225/300/375/450mW$^2$) during 20 sec. Polymerization shrinkage of samples was detected continuously by IB system during 110 sec and the rate of polymerization shrinkage was obtained by its shrinkage data. Peak time(P.T.) showing the maximum rate of polymerization shrinkage was used to compare the polymerization rate. Results : Peak time decreased with increasing light intensity(p<0.05). Maximum rate of polymerization shrinkage increased with increasing light intensity(p<0.05). Statistical analysis revealed a significant positive correlation between peak time and inverse square root of the light intensity (AF:R=0.965, Zl:R=0.974, SF:R=0.927). Statistical analysis revealed a significant negative correlation between the maximum rate of polymerization shrinkage and peak time(AF:R=-0.933, Zl:R=-0.892, SF:R=-0.883), and a significant positive correlation between the maximum rate of polymerization shrinkage and square root of the light intensity (AF:R=0.988, Zl:R=0.974, SF:R=0.946). Discussion and Conclusions : The polymerization rate of composite resins used in this study was proportional to the square root of light intensity Maximum rate of polymerization shrinkage as well as peak time can be used to compare the polymerization rate. Real-time volume method using IB system can be a simple alternative method to obtain the polymerization rate of composite resins.

Results of Hyperfractionated Radiation Therapy in Bulky Stage Ib, IIa, and IIb Uterine Cervical Cancer (종괴가 큰 병기 Ib, IIa, IIb 자궁경부암에서 다분할 방사선치료의 결과)

  • Kim, Jin-Hee;Kim, Ok-Bae
    • Radiation Oncology Journal
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    • v.15 no.4
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    • pp.349-356
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    • 1997
  • Purpose : To evaluate the efficacy of hyperfractionated radiation therapy in carcinoma of the cervix, especially on huge exophytic and endophytic stage Ib, IIa and IIb Materials and Materials : Fourty one patients with carcinoma of the cervix treated with hyperfractionated radiation therapy at the Department of Therapeutic Radiology, Dongsan Hospital, Keimyung University. School of Medicine from Jul, 1991 to Apr, 1994. According to FIGO s1aging system, therewere stage Ib (3 patients) IIa (6 patients) with exophytic ($\geq$5cm in dinmeter) and huge endophytic mass. and IIb (32 patients) with median age of 55 yeavs old. Radiation therapy consisted of hyperfractionated external irradition to the whole pelvis (120cGy/fraction, 2 fraction/day (minimum interval of 6 hours), 3600-5520cGy) and boost parametrial doses (for a total of 4480-6480cGy) with midline shield $(4\times10cm)$, and combined with intracavitary irradiation (up to 7480-8520cGy in Ib, IIa and 8480-9980cGy in IIb to point A). The maximum and mean follow up durations were 70 and 47 months respectively . Results : Five year local control rate was $78\%$ and the actuarial overall five year survival rate was $66.1\%$ for all patients, $44.4\%$ for stage Ib, IIa and $71.4\%$ for stage IIb. In bulky IIb (above 5cm in tumor size, 11 patients) five year local control rate and five rear survival rate was $88.9\%,\;73\%$ respectively Pelvic lymph node status (negative : $74\%,\;positive:25\%$, p=0.0015) was significant Prognostic factor affecting to five rear survival rate. There was marginally significant survival difference by total dose to A point ($>84Gy\;:\;70\%,\;>84Gy\;:\;42.8\%$, p=0.1). We consider that the difference of total dose to A point by stage (mean Ib,IIa : 79Gy. IIb 89Gy P=0.001) is one of the causes in worse local control and survival of Ib,IIa than IIb The overall recurrence rate was $39\%$ (16/41). The rates of local failure alone. distant failure alone. and combined local and distant failure were $9.7\%,\;19.5\%,\;and\;9.7\%$, respectively. Two Patients developed leukopenia ($\geq$ grade 3) and Three patients develoued grade 3 gastrointestinal complication. Above grade 3 complication was not noted. There was no treatment related death noted. Conclusion : We thought that it may be necessary to increase A point dose to more than 85Gy in hyperfractionated radiotherapy of huge exophytic and endophvtic stage Ib,IIa. We considered that hyperfractionated radiation therapy may be tolerable in huge exophytic and endophytic stage IIb cervical carcinoma with acceptable morbidity and possible survival gain but this was results in small patient group and will be confirmed by long term follow up in many patients.

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The Development of Car Service Management Information System on Web (Web을 이용한 자동차 정비업소 경영 정보 시스템 개발)

  • Jung, Sang-Tae;Hong, Sung-Chan;Jang, Myung-Hwan;Lee, Hyung
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2000.11a
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    • pp.787-791
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    • 2000
  • 최근 들어 인터넷 보급이 폭발적인 증가를 보이면서 인터넷 비즈니스(Internet Business) 또는 전자 상거래(EC : Electronic Commerce)에 대한 관심이 급속도로 확산되고 있다. 외국은 물론 대부분의 국내 대기업과 중ㆍ소기업에서는 사운을 내걸고 인터넷 비즈니스 시스템(IBS : Internet Business System)에 대한 투자를 감행하고 있으며, 또한 수많은 개인 업자(SOHO)들도 인터넷 비즈니스(IB)를 통하여 창의적인 신규 사업에 뛰어들고 있는 실정이다. 이러한 인터넷 비즈니스(IB)는 고객에게 가치 있는 무엇인가를 제공해 줄 수 있어야하며, 그 대가를 인터넷을 통해 보상받을 수도 있어야 한다. 이러한 원리 속에서 인터넷은 경제적, 기술적인 도약을 통해 급속도로 확산되리라는 것이 전문가들의 공통적인 전망이다. 또한, web을 통한 자동차 정비업소 경영 정보관리 시스템과 같은 ASP(Application Service Provider)에 많은 관심이 쏠리고 있다 본 연구는 중소 업체를 향한 인터넷 이용 경영 정보관리 시스템이 현재는 미약한 실정임을 파악, 이런 시대적 요구사항과 필요성에 의해 Web을 이용한 자동차 정비업소 경영 정보 시스템을 개발한다.

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