• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.427-432
• /
• 2005

This paper is concerned with a simultaneous design of TSK (Takagi-Sugeno-Kang)-linguistic fuzzy models with uncertain model output and the computationally efficient representation. For this purpose, we use the fundamental idea of linguistic models introduced by Pedrycz and develop their comprehensive design framework. The design process consists of several main phases such as (a) the automatic generation of the linguistic contexts by probabilistic distribution using CDF (conditional density function) and PDF (probability density function) (b) performing context-based fuzzy clustering preserving homogeneity based on the concept of fuzzy granulation (c) augment of bias term to compensate bias error (d) combination of TSK and linguistic context in the consequent part. Finally, we contrast the performance of the enhanced models with other fuzzy models for automobile MPG predication data and coagulant dosing process in a water purification plant.

• Journal of the Korean Statistical Society
• /
• 제25권4호
• /
• pp.557-566
• /
• 1996

The aim of this paper is to find a suitable design which minimizes the expected discrepancy: in fitting a first order model fearing quadratic terms as bias where there are more than two correlated responses. Kim and Draper(1994) discussed about choosing a design for straight line fits to two correlated responses The general case with r responses is examined here and the result is applied to a specific case to help understandings.

• 품질경영학회지
• /
• 제15권2호
• /
• pp.69-73
• /
• 1987

The aim of this study is to find out the optimal goods for the marketing research through analysing the factor effecting the marketing survey by using the experimental design method. The decisive effecting factors in relation with the marketing survey were investigated as follows; 1. A row effect (Ai; i = 1, 2, ... n) is the design sorts of woman-clothes bias. 2. A column effect (Bi; i = 1, 2, ... n) is the woman-consumer bias. In this paper the experimental design, execution and statistical analys is were conducted to find out the optimal goods for marketing research.

• 한국전자파학회논문지
• /
• 제22권7호
• /
• pp.683-693
• /
• 2011

본 논문에서는 고출력 증폭기의 바이어스를 위한 대전류 마이크로파 광대역 바이어스-티의 설계를 보였다. DC 블록용 커패시터는 큰 어드미턴스를 가지도록 커패시터의 병렬합을 이용하고, DC 공급 및 RF 초크용 인덕터는 광대역의 큰 임피던스를 가지는 인덕터의 직렬합을 이용하여 설계하였다. DC 블록이나 RF 초크에 사용되는 인덕터나 커패시터는 자기 공진 주파수(SRF: Self Resonance Frequency)를 가지고 있어 사용 대역이 제약된다. 이를 해결하기 위해 RF 초크에서는 저항을 추가하여 공진 주파수에서 품질 계수를 조정함으로써 해결하였다. 그리고 DC 블록에서는 별도의 품질 계수 조정없이 병렬합만으로 가능하였다. 이 결과를 이용하여 1608 칩 형태의 집중 소자들을 표면 실장 기법(surface mount)으로 PCB 패턴에 조립하여 바이어스-티를 제작하였다. 제작된 바이어스-티는 10 MHz~10 GHz에서 측정된 반사 손실이 10 dB 이하를 가지며, 입력 임피던스는 광대역에서 50 ohm 근처의 값을 만족하는 것을 확인하였다.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제13권2호
• /
• pp.87-97
• /
• 2013

Negative bias temperature instability (NBTI) and positive bias temperature instability (PBTI) are critical circuit reliability issues in highly scaled CMOS technologies. In this paper, we analyze the impacts of NBTI and PBTI on SRAM $V_{MIN}$, and present a design solution for mitigating the impact of NBTI and PBTI on SRAM $V_{MIN}$. Two different types of SRAM $V_{MIN}$ (SNM-limited $V_{MIN}$ and time-limited $V_{MIN}$) are explained. Simulation results show that SNM-limited $V_{MIN}$ is more sensitive to NBTI while time-limited $V_{MIN}$ is more prone to suffer from PBTI effect. The proposed NBTI/PBTI-aware control of wordline pulse width and woldline voltage improves cell stability, and mitigates the $V_{MIN}$ degradation induced by NBTI/PBTI.

• Journal of the Korean Data and Information Science Society
• /
• 제25권5호
• /
• pp.1127-1135
• /
• 2014

Genome-wide association studies (GWAS) are designed to discover genetic variants such as single nucleotide polymorphisms (SNPs) that are associated with human complex traits. Although there is an increasing interest in the application of GWAS methodologies to population-based cohorts, many published GWAS have adopted a case-control design, which raise an issue related to a sampling bias of both case and control samples. Because of unequal selection probabilities between cases and controls, the samples are not representative of the population that they are purported to represent. Therefore, non-random sampling in case-control study can potentially lead to inconsistent and biased estimates of SNP-trait associations. In this paper, we proposed inverse-probability of sampling weights based on disease prevalence to eliminate a case-control sampling bias in estimation and testing for association between SNPs and quantitative traits. We apply the proposed method to a data from the Korea Association Resource project and show that the standard estimators applied to the weighted data yield unbiased estimates.

• 유통과학연구
• /
• 제21권6호
• /
• pp.99-106
• /
• 2023

Purpose: This study aims to analyze the distribution of the role of adversity quotient in the estimation bias of future earnings. Adversity quotient is a cognitive ability that can be distributed as a reducer of bias effects that occur in profit forecasting or investment decision making. Research design, data and methodology: The study designs a full factorial within-subject 2×3 as a laboratory experiment. The study subjects are 30 accounting students who are proxied as investors. Results: The results show that the estimated earnings made by investors experience anchoring-adjustment heuristic bias which means the initial value becomes a basic belief that influences the decisions taken by investors. However, this study also provides evidence that heuristic bias can be reduced by the presence of adversity quotient. Investors who have high adversity ability are abler to reduce the estimation bias when compared to investors who have medium and low adversity ability so the higher the difficulty ability possessed by investors, the less likely the occurrence of bias in decision making. Conclusion: Thus, the adversity quotient is proven to be distributed as a reducing opportunity from the bias that will occur in estimating future earnings or making investment decisions.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2002년도 춘계학술대회논문집
• /
• pp.554-558
• /
• 2002

A magnetostrictive sensor is used to measure stress waves propagating in a ferromagnetic cylinder without physical contact. The performance of a magnetostrictive sensor is affected most significantly by the bias magnetic field applied around the measurement location. The goal of this paper is to carry out the topology optimization of the bias magnet and yoke assembly to maximize the sensor output for traveling bending waves. We will use the multi-resolution topology optimization strategy to find the assembly of the bias magnet and the yoke that is easy to realize. The effectiveness of the present design is confirmed by an actual measurement of the sensor signal with the proposed bias magnet and yoke configuration.

• Communications for Statistical Applications and Methods
• /
• 제17권4호
• /
• pp.515-525
• /
• 2010

본 논문에서는 패널회귀모형에서 회귀계수의 일반최소제곱추정량과 가중최소제곱추정량의 설계기반 성질을 살펴보았다. 복합표본이 주어진 경우에 두 추정량의 설계편향을 구하여 가중최소제곱추정량의 설계편향의 크기가 더 작음을 보였다. 또한 한국복지패널 데이터를 대상으로 모의실험을 실시하여 다음의 결과를 얻었다. 첫째, 일반최소제곱추정치의 상대편향이 가중최소제곱추정치의 상대편향보다 약 2배 정도 크게 나타났고 일반최소제곱추정치의 편향비가 더 크게 나타났다. 그리고 표본수가 증가하면 일반최소제곱 추정치의 상대편향은 완만하게 줄어든 반면 가중최소제곱추정치의 상대편향은 급속도로 줄어들었다. 둘째, 표본수가 증가하면 일반초소제곱추정치와 가중최소제곱추정치의 분산과 평균제곱오차는 모두 줄어들였다. 그러나 평균제곱오차에서 차지하는 편향제곱의 비율은 표본수가 증가할 때 일반최소제곱추정치에서는 증가하는 반면 가중최소제곱추정치에서는 감소하는 경향이 나타났다. 마지막으로 거의 모든 경우에 일반최소제곱추정치의 분산이 가중최소제곱추정치의 분산보다 작게 나타났다. 그리고 많은 경우에 일반최소제곱추정치의 평균제곱오차가 가중최소제곱추정치의 평균제곱오차보다 작게 나타났다. 그러나 표본수가 증가할수록 일반최소제곱추정치의 평균제곱오차가 가중최소제곱추정치의 평균제곱오차보다 커지는 경우가 늘어났다.

• 한국항행학회논문지
• /
• 제13권3호
• /
• pp.358-364
• /
• 2009

본 논문에서는 설계된 전력증폭기에서 가변 바이어스 기법을 이용하면 전력부가효율을 증가시킬 수 있다는 것을 보였다. 서로 다른 출력전력을 갖는 이중 모우드에서 높은 효율을 얻기 위하여 가변 바이어스 기법을 이용하고 바이어스 변화에 따른 영향을 시뮬레이션 하였다. 게이트 전압을 고정하고 드레인 바이어스를 시뮬레이션으로 최적값을 구하여 이를 변화하여 전력증폭기의 효율을 향상시킬 수 있었다. 또한 전력증폭기의 비선형 특성을 분석하고 디지털 사전왜곡 기법을 이용하여 이중 대역 증폭기의 송신기의 ACPR 특성을 최대 10dB 개선되었다.