• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권10호
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• pp.4640-4661
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• 2018

To cope with the explosive growth of Internet services, Service Function Chaining (SFC) based on Software-defined Networking (SDN) is an emerging and promising technology that has been suggested to meet this challenge. Determining the placement of Virtual Network Functions (VNFs) and routing paths that optimize the network utilization and resource consumption is a challenging problem, particularly without violating service level agreements (SLAs). This problem is called the optimal SFC placement problem and an Integer Linear Programming (ILP) formulation is provided. A greedy heuristic solution is also provided based on an improved two-step mapping algorithm. The obtained experimental results show that the proposed algorithm can automatically place VNFs at the optimal locations and find the optimal routing paths for each online request. This algorithm can increase the average request acceptance rate by about 17.6% and provide more than 20-fold reduction of the computational complexity compared to the Greedy algorithm. The feasibility of this approach is demonstrated via NetFPGA-10G prototype implementation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.459-459
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• 2000

The purpose of this paper is the application of the techniques for the new estimation of robustness for the aircraft systems having structured uncertainties. The basic ideas to analyze the system which is the originally nonlinear is Lyapunov direct theorems. The nonlinear systems have various forms of terms inside the system equations and this investigation is confined in the form of bounded uncertainties. The number of uncertainties will be the degree of freedoms in the calculation of the robust stability regions called the robustness bounds. This proposition adopts the theoretical analysis of the Lyapunov direct methods, that is, the sign properties of the Lyapunov function derivative integrated along finite intervals of time, in place of the original method of the sign properties of the time derivative of the Lyapunov function itself. This is the new sufficient criteria to relax the stability condition and is used to generate techniques for the robust design of control systems with structured perturbations. Using this relaxing stability conditions, in this paper, the quadratic form of Lyapunov function is utilized. In this paper, the practical system of vertical take-off and landing (VTOL) aircraft is analyzed with the proposed stability criteria based upon the Lyapunov direct method. The application of numerical procedures can prove the improvements in estimations of robustness with structured uncertainties. The applicable aircraft system is assumed to be linear with time-varying with nonlinear bounded perturbations.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제21권4호
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• pp.575-596
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• 2007

본 논문은 예비교사들이 함수교육과 관련된 subjective-matter knowledge와 pedagogical content knowledge를 어떻게 효율적으로 의미있게 학습하고 발전시키는 가에 대하여 조사하였다. 함수의 기본개념과 원칙, 그리고 그들이 어떻게 조직되었는지를 이해하는 능력과 의미있는 함수학습이 가능하도록 그들을 표현하고 구성하는 능력을 증진시키기 위하여 본 연구에서는 구성주의와 협동학습에 기반 한 학습방법을 채택하였다. 사전, 사후테스트와 인터뷰를 통하여 평가한 결과 소그룹 구성원들과의 상호작용 결과를 전체 구성원과의 토론을 통하여 학습하는 과정에서 보다 깊이 있고 확장된 subject-matter knowledge와 다양한 pedagogical content knowledge를 획득하게 되는 결과를 얻게 되었다.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2008년도 춘계학술발표대회 논문집
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• pp.245-250
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• 2008

The city means not only a geographical area as a role of the spatial boundary, but also a socio-economic place to communicate with each part. It requires various functions to get the income and activities. But city has a limitation of a available land to provide the required function and a sufficient space to supply the activity. Therefore, the development trend of city has not been to spread to the horizontal area any more and considered the vertical area. In addition, various functions put into a massive building because many people want to solve the daily requirements without spending time and cost. In this paper, it aimed at classifying the mixed-use building into function, circulation, relation between the public and private space and the building shape to provide the design information according to the development constraints such as land area, functional limitation, accessibility, etc. The classification of the mixed-use buildings is divided into four areas. The data are collected with foreign countries in Japan, Europe and US.

• Clinical and Experimental Reproductive Medicine
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• 제47권1호
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• pp.12-19
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• 2020

Objective: The appropriate function of the hypothalamic-pituitary-gonadal axis is essential for maintaining proper reproductive function. In female mammals, the hypothalamic-pituitary-gonadal axis regulates reproductive changes that take place in the estrus cycle and are necessary for successful reproduction. This study was conducted to investigate the effect of thymectomy on the estrus cycle in neonatally thymectomized guinea pigs. Methods: In this study, 12 female guinea pigs, six thymectomized and six sham-operated, were studied. The effects of neonatal thymectomy at 5-7 days of age on parameters of the reproductive axis were examined in female guinea pigs. Gonadotropin and 17β-estradiol levels were assessed at regular intervals (days 0, 3, 6, 9, 12, and 15) of the estrus cycle, and the time of vaginal opening in the thymectomized and shamoperated guinea pigs was determined. Results: Significant reductions in gonadotropins and 17β-estradiol levels during estrus cycle were found in neonatally thymectomized female guinea pigs compared to sham-operated guinea pigs. Conclusion: The results of this study underscore the importance of the thymus in the neonatal period for normal female reproductive function.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.491-498
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• 2002

Dredged and reclaimed soft clays form slurry state which is very high water content and very low shear strength, experience large self-weight consolidation, nonlinear compressibility and permeability phenomenon would take place. In this case, a material functions which represent variety effective stress-void ratio-permeability relation (especially very low effective stress), are should be determined to predict nonlinear finite strain consolidation phenomenon forehand In this study, large slurry consolidometer with a 380mm diameter and a 1400mm height which is able to consolidation and permeability test, was developed to determine material function of very soft clay with a 500% initial water content clay, self-weight consolidation and low stress level consolidation (1Kpa, 3Kpa, 6Kpa, 12Kpa) was conducted and after each consolidation step permeability test also conducted. after final consolidation step, a constant rate of strain consolidation was conducted with undisturbed sample obtained from the large consolidometer. On the above result, material function was determined and laboratory test was modelled to evaluate its validity, numerical analysis on th field was compared to other method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.483-488
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• 2013

The psychoacoustic quality of ABS is now considered more important than before as the focus of recent ABS function is expanded to basic function from typical emergency function. Thus, the automotive parts manufacturing companies are actively working to improve NVH (Noise, Vibration, and Harshness) in ABS module. In terms of time, test place, and cost, however, it is very inefficient to have all the operating noise validation test in real vehicle configuration especially for partially improved ABS module. To contribute to reducing the development period and to grasping the improvements faster, this research presents the study of a correlation to predict ABS operating noise inside vehicle via HILS rig test. The regression equation in this paper was statistically drawn from using Minitab S/W, and based on that equation, the noise spectrum of vehicle interior was analogized.

• 디지털융복합연구
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• 제6권3호
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• pp.149-158
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• 2008

This study identifies the present status of multicultural broadcasting programs as multicultural phenomenon is spreading throughout Korean society and it discusses how a local broadcasting has to reflect locality and multicultural characteristic. A notion on the local of multimedia and multichannel time is expanding as a concept of emotional and psychological territory over geographical space. Therefore the locality should reflect attachment and interests of its members as well as disseminating multicultural reality. A locality for broadcasting should accept differences, reflect a cultural diversity, and satisfy its dynamics. The purpose of this study is to inquire whether a local broadcasting is performing its function as a local press and a place forpublic opinions by examining how they reflect reality of local, where an inflow of Immigrants and their cultures are altering the place as a multicultural society, and what Programs they propose. This study also presents media education for immigrants, revitalization of community, multicultural education about local citizens, and practical use of multicultural contents and small output radio as a source of supply for local broadcasting program in order to harmonize production of multlcultural media contents In local society.

• 한국실내디자인학회논문집
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• 제21권1호
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• pp.127-135
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• 2012

Recently, the public design plays a role in improving the residents' quality of life and activating the local economy as an axis of the regional development. However, during the development process led by the local government, the public space has been changed to a place where only the function is emphasized without considering the local history, culture, and life. Since the opinions of the regional residents are not reflected, the public place lacks public benefits and has difficulties in continuous improvement and development. Here, we studied on the participation of residents in public design. Firstly, we discussed public design that residents can participate voluntarily and actively as users, managers, and beneficiaries. Secondly, it is necessary for the residents, who are not experts in the public design, to have easily understandable and well tractable communication media which facilitate communications with a group of the design experts and the public service personnel. We explained the types and specialities of the communication media. Thirdly, it is necessary for the residents to contribute much to the local development by active participation in the sustainable and consistent public design through using the easily accessible communication media.

• 대한기계학회논문집A
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• 제22권1호
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• pp.73-79
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• 1998

The development of a new material which should be continuously usable under severe environment of very high temperature has been urgently requested. The conventional thermal barrier coating(TBC) is a two layer coating, but a composition and a microstructure of functionally graded material(FGM) are varied continuously from place to place in ways designed to provide it with the maximum function of mitigating the induced thermal stress. The purpose of this study is to evaluate the heat-resistant characteristics by thermal shock of laser and furnace heating. The fracture behaviors of non-FGM(NFGM) and FGM were investigated based on acoustic emission(AE) technique during thermal shock test. Therefore, it can be concluded that FGM gives higher thermal resistance compared to NFGM by AE signal and fracture surface analysis.