• ETRI Journal
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• 제22권4호
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• pp.1-12
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• 2000

Designing a reliable multicast-based network that scales to the size of a multicast group member is difficult because of the diversity of user demands. The loss inferences of internal nodes by end-to-end measurements do not require the use of complete statistics because of the use of maximum likelihood estimation. These schemes are very efficient and the inferred value converges fast to its true value. In the theoretical analysis, internal delay estimation is possible but the analysis is very complex due to the continuity property of the delay. In this paper, we propose the use of a bottleneck location estimator. This can overcome the analytical difficulty of the delay estimation using the power spectrum of the packet interarrival time as the performance metric. Both theoretical analysis and simulation results show that the proposed scheme can be used for bottleneck location inference of internal links in scalable multicasting.

• Nuclear Engineering and Technology
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• 제31권3호
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• pp.257-266
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• 1999

A simplified statistical methodology is developed in order to both reduce over-conservatism of deterministic methodologies employed for PWR fuel rod internal pressure (RIP) calculation and simplify the complicated calculation procedure of the widely used statistical methodology which employs the response surface method and Monte Carlo simulation. The simplified statistical methodology employs the system moment method with a deterministic approach in determining the maximum variance of RIP The maximum RIP variance is determined with the square sum of each maximum value of a mean RIP value times a RIP sensitivity factor for all input variables considered. This approach makes this simplified statistical methodology much more efficient in the routine reload core design analysis since it eliminates the numerous calculations required for the power history-dependent RIP variance determination. This simplified statistical methodology is shown to be more conservative in generating RIP distribution than the widely used statistical methodology. Comparison of the significances of each input variable to RIP indicates that fission gas release model is the most significant input variable.

• 한국기술혁신학회:학술대회논문집
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• 한국기술혁신학회 2017년도 춘계학술대회 논문집
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• pp.357-391
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• 2017

In this study, we suggest a new perspective on the linkage between alliance portfolio diversity and innovation performance based on a contingency approach. Using a longitudinal data set on alliance portfolios and patents of 182 firms in the U.S. manufacturing industries, we examined that alliance portfolio diversity has a U-shaped relationship with firm-level innovation. Internal value creation capabilities in terms of routine and ability are found to moderate the relationship between alliance portfolio diversity and innovation performance: Organizational search routine strengthens the relationship of alliance portfolio diversity and innovation performance while technological capabilities weaken and flip the relationship.

• 농촌계획
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• 제9권3호
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• pp.17-23
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• 2003

This paper aimed at identifying rural amenities valuable in terms of marketed value and economic analysis of green tourism so as to develop policy instruments for new rural communities. We conducted the case study on Jik-Dong rural community in Taejeon city and estimated income effects of green tourism and internal rate of return of investment for rural amenity facilities. The research results are as followings; (1) green tourism participant will spend the worth of 50,392 won per person, (2) earnings from green tourism amounts to about 2,471 thousand won per household, (3) internal rate of return of green tourism investment is estimated as 7%. The strategies far green tourism is suggested as follows; (1) rural amenities should be well maintained for green tourism infrastructure (2) measures to internalize the value of rural amenities should be developed for market oriented peen tourism (3) effective program for inducing visitors with purchasing power should be designed.

• Tuberculosis and Respiratory Diseases
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• 제57권5호
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• pp.419-424
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• 2004

연구배경 : 기관지확장제 가역성 검사는 천식이나 COPD를 진단하거나 감별 진단할 때에 널리 사용하고 있지만 실제 천식과 COPD를 감별 진단하는데 도움이 되는지에 대해서 이견이 있고 기관지확장제 가역성을 평가하는 방법에 대해서도 일치된 의견이 없다. 기관지확장제 가역성 검사가 천식과 COPD를 감별 진단하는데 역할을 알아보고 기관지확장제 가역성 검사를 어느 방법으로 하는 것이 좋은지 알아 보았다. 방 법 : 천식 환자 26명과 COPD 환자 31명을 후향적으로 연구하였다. 기관지확장제를 흡입한 전후에 폐활량측정법을 시행하여 $FEV_1$, FVC를 얻었다. 기관지확장제 가역성 검사를 평가하는데 '기저치에 대한 백분율'과 '예측치에 대한 백분율' 그리고 '증가 절대값' 방법을 사용하였고 ROC curve의 곡선하 영역을 측정하여 비교하였다. 기관지확장제 가역성을 판단하는 기준 중 미국흉부학회 기준과 유럽호흡기학회 기준을 비교하였다. 결 과 : (1) '기저치에 대한 백분율' 방법으로 기관제확장제 가역성을 평가하였을 때 천식과 COPD를 감별 진단하는데 도움이 되지 않았지만 '예측치에 대한 백분율'이나 '증가 절대값' 방법으로 평가하였을 때는 도움이 되었다. 하지만, ROC curve의 곡선하 영역이 어느 방법을 쓰더라도 0.75 미만이므로 천식과 COPD를 감별 진단하는 능력은 약하였다. (2) 유럽호흡기학회 기준으로 기관지확장제 가역성을 평가하면 미국흉부학회 기준보다 양성 결과 우도비가 더 크고 음성 결과 우도비가 더 작으므로 천식과 COPD를 감별 진단하는데 유럽호흡기학회 기준이 더 좋았다. 결 론 : 기관지확장제 가역성은 천식과 COPD를 감별 진단하는데 도움을 줄 수 있기는 하지만 그 도움 정도가 약하므로 보조적인 검사로 사용하는 것이 좋을 것이다.

• 한국농공학회지
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• 제45권6호
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• pp.172-182
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• 2003

In this study, the back analysis was performed by means of stereo-net, plane failure and block failure method to collapsed fields among the rock slopes designed by standardized criterion, and the internal frictions from the back analysis were compared with those used to reinforcement design. It was concluded that in the result of the analysis by means of stereo net, plain failure and block failure methods, the internal frictions used to re-design of collapsed slope underestimated 10$^{\circ}$, 5$^{\circ}$ and 10$^{\circ}$ in average. At present, the internal friction on the design is used the experience value according to the state of weathering, but internal friction angle by the back analysis on collapsed slope with various methods were more reliable values than those from the present method. And it was concluded that re-design was made extravagantly because the internal friction used to re-design for reinforcement of the collapsed slope was less than back analysis.

• 플랜트 저널
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• 제8권1호
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• pp.73-80
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• 2012

The structure and combustion characteristics, and the economic feasibility of the circulating fluidized bed combustion(CFBC) boiler using low grade coal were introduced. The economic feasibility is evaluated by comparing a 500 MW CFBC boiler power plant using low grade coal and a pulverized combustion boiler power plant with high grade coal. As the result of the evaluation, the pulverized coal combustion boiler power plant has an internal rate of return of 12.95%, 1,395.9 billion Korean won of net present value, and 6.26 years of payback period. On the other hand, CFBC boiler power plant has an internal rate of return of 13.54%, 1,704.3 billion Korean won of net present value, and 6.02 years payback period. Therefore, the CFBC boiler power plant has better feasibility in all aspects, as 0.59% higher of internal rate of return, 308.4 billion Korean won of higher net present value and 0.24 year of shorter payback period.

• Journal of applied mathematics & informatics
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• 제34권1_2호
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• pp.75-84
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• 2016

The objective of this work is to perform a geometric analysis of the net present value (NPV) and Internal Rate of Return (IRR), defining analytics and in verifying the relationship between geometric properties of such functions. For this simulation, was used the values of the cash flows for each period identical and equal to US$ 200.00 cash, the initial investment US$ 1,000.00 and investments of each identical and equal to US$ 50.00 period. In addition, the discount rate and time were considered a maximum of 2 years (24 months) at a rate between 0 and 100%. The geometric analysis of the characteristics obtained from the expressions of the Net Present Value and Internal Rate of Return possible to observe that besides the analytical dependence between these quantities , the geometric relationships are relevant when studied in relation to the zero NPV and expressed a great contribution the sense of a broad vision for the administrator in the analysis of analytical variables that in uences the balance sheet of the company.

• 전자공학회논문지SC
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• 제46권3호
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• pp.8-14
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• 2009

본 논문은 성능 향상을 위하여 IMC 제어 구조를 갖는 PID 제어기 설계를 제안했다. 내부 모델은 최종값 정리와 유전자 알고리즘을 이용하여 2차의 지연시간을 갖는 모델로 동정 하였다. 그리고 제어기 파라미터 값은 성능지수 (IAE, ITAE)값이 최소가 되도록 내부 모델과 수치적 계산에 의해서 자동 동조된다. 시뮬레이션을 통하여 다양한 공정에 대하여 본 논문에서 새롭게 제안된 방법이 기존의 방법보다 우수함을 확인 할 수 있었다.

• 전기의세계
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• 제13권4호
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• pp.25-29
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• 1964

This paper shows that higher amplification can be achieved by applying load current on the internal feedback winding of the magnetic amplifier under test. Since the magnetic flux of the control winding and internal feedback winding saturate the core more fully, the permeability tends to zero and load current increases to the value more than that of ordinary magnetic amplifier without feedback.