• Journal of applied mathematics & informatics
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• v.9 no.1
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• pp.185-195
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• 2002

Previous research has shown that the flow of patients around departments of geriatric medicine and ex-patients in the community may be-modelled by the application of a mixed-exponential distribution. In this proper we considered a ave-compartment model using a continuous-time Markov process to describe the flow of patients. Using a M/ph/c queuing model, we present a way of optimizing the number of beds in order to maintain an acceptable delay probability a sufficiently low level. Finally, we constructed a Java computer simulation, using data from St George's Hospital, London.

• ETRI Journal
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• v.33 no.5
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• pp.826-829
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• 2011

Distributed systems particularly suffer from Sybil attacks, where a malicious user creates numerous bogus nodes to influence the functions of the system. In this letter, we propose a Bloom filter-based scheme, SybilBF, to fight against Sybil attacks. A Bloom filter presents a set of Sybil nodes according to historical behavior, which can be disseminated to at least n (e-1)/e honest nodes. Our evaluation shows that SybilBF outperforms state of the art mechanisms improving SybilLimit by a factor of (1/e)${\gamma}$ at least.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.274-278
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• 2002

The purpose of this study was to characterize the reaction of Cu surface with Cu slurry and CMP performance as a function of additives in CMP slurry. The polish rate of Cu was dependent on the kind of organic acids added in slurry. It was considered that polish rate of Cu was dependent on the concentration of carboxylates and mean particle size. When the etchant and oxidant were added in slurry, the highest removal rate and lower etch rate were measured at neutral pH. The addition of etchant, oxidant and pH adjustor played key roles of CMP ability in slurry. As the pH increased, polish rate of Cu was increased by the enhanced the mechanical effects due to effective dispersion of slurry particles. Alumina abrasives was more desirable for 1st step slurry because of high removal rate of Cu and high selectivity ratio among TaN and Cu.

• Water Engineering Research
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• v.3 no.3
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• pp.203-213
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• 2002

A wide-angle parabolic approximation equation model considering the interaction between wave and current is employed to simulate the deformation of irregular waves over a submerged shoal. It is found that the model gives qualitative agreements with experimental data for the cases of breaking waves around the shoal. Thus, the effect of breaking-induced current on the refraction-diffraction of waves is well understood.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.362-365
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• 2001

앞으로의 컴퓨터 시스템은 호스트 집중형 매인프레임 컴퓨팅, 클라이언트/서버, 분산객체, ERP시스템 등으로 발전하는 것으로 전망된다. 메인프레임을 통한 호스트 중심의 중앙집중형 시스템이 네트워크와 PC의 발전으로 클라이언트/서버 시스템의 시대를 열었다. 분산 환경에서 사용자들은 여러 저장 장치로부터 정보를 얻을 수 있고 서로 다른 이질적인 시스템에 있는 사용자들과 함께 자료를 공유, 통신할 수 있어야 한다. 때문에 분산 애플리케이션을 작성하기 위해서는 일단 서로 다른 운영체계와 네트워크 환경 등으로 구성된 이질적이고 복잡한 환경을 전제로 삼아야 한다. 이러한 환경에서 클라이언트/서버 소프트웨어를 개발하고 이를 서로 다른 시스템과 쉽게 통합할 수 있기 위해서는 이종의 분산 환경에서 여러 종류의 옹용 프로그램을 통합할 수 있는 표준의 결합 방식이 필요하다. 분산 객체 시스템과 ERP시스템이 도입ㆍ구축되었다고 해서 기업의 경쟁력이 강화되고 이윤 극대화가 달성되고 고객만족이 이루어지는 것은 아니다. 최적의 ERP시스템을 구축하기 위해서 도입단계에서부터 체계적인 접근이 필요하다. 본 연구에서는 ERP서버의 현황과 분산객체 미들웨어를 활용한 ERP서버에 대해 기술하고 ERP시스템 도입에 대한 분석을 시도함으로써 ERP 시스템의 성공적인 도입전략에 대해 연구하였다.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.990-992
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• 1996

The design of I/O scaling factors for fuzzy controller system is proposed in this paper. The proposed method is for nonlinear input scaling factor and variable output scaling factor. The fuzzy controller is evaluated by computer simulation on the 1st order process and 2nd order process. Simulation results showed robust characteristics for variable reference signal.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.193-193
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• 2002

The subacute toxicities and toxicokinetics of a new fluoroquinolone antibiotics, DW-224a, were evaluated after single (at the 1st day) and 4-week (at the 28th day) oral administration of the drug, in doses of 0 (to serve as a control), 10, 30 and 90 mg/kg/day, to male and female dogs (n = 3 for male and female dogs for each dose).(omitted)

• Bulletin of the Korean Chemical Society
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• v.19 no.10
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• pp.1073-1079
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• 1998

The potential energy surface (PES) of the non-identical SN2 reactions, F- + CH3Cl → FCH3 + Cl and (H2O)F + CH3Cl → FCH3 + Cl-(H2O), were investigated with ab initio MO calculations. The ab initio minimum energy reaction path (MERP) of the F- + CH3Cl → FCH3 + Cl- was obtained and it was expressed with an intermediate variable t. The ab initio PES was obtained near around t. Analytical potential energy function (PEF) was determined as a function of the t in order to reproduce the ab initio PES. Based on Morse-type potential energy function, a Varying Repulsive Cores Model (VRCM) was proposed for the description of the bond forming and the bond breaking which occur simultaneously during the SN2 reaction. The MERP calculated with the PEF is well agreed with the ab initio MERP and PEF could reproduce the ab initio PES well. The potential parameters for the interactions between the gas phase molecules in the reactions and water were also obtained. ST2 type model was used for the water.

• Korean Journal of Plant Resources
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• v.21 no.3
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• pp.226-229
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• 2008

We described and illustrated a rare species in Korea, Hypoxis aurea Lour. (Hypoxidaceae) which was rediscovered about 70 years after its first collection from Jeju island in Korea. The members of the family Hypoxidaceae R. Br. are distinguished from the plants of Amaryllidaceae J. St-Hill. by having grass-like leaves, an invisible stem which is modified into a corm or a rhizome, trimerous, and radially symmetric flowers with an inferior ovary developing into a capsule on scapes. Hypoxis aurea Lour. is readily distinguishable from Curculigo orchinoides Gsertn. in Japan by beakless ovary and capsular fruit. The number of somatic chromosome is 2n=54.

• Journal of Korean Academy of Medicine & Therapy Science
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• v.10 no.2
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• pp.13-20
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• 2018

Objective: To investigate the effects of a brain fitness exercise on the cognitive function of patients with dementia. Method: Forty-six elderly adults diagnosed with dementia were randomly allocated to the study or control group (n=23 per group). The study and control groups performed a brain fitness and regular exercise, respectively, for 40 minutes a day, three times a week for four weeks. We examined cognitive capacity using MMSE-K, cognitive strength, judgment time, and mental workload scores before and after intervention. Results: The study group showed significant improvements in all variables. In addition, the control group showed a significant improvement in brain stress. We found that there was a significant improvement in the study group when compared with the control group in all variables. Conclusion: Based on these results, we suggest that brain fitness exercise would be effective in improving cognitive functions of dementia patients.