• 한국추진공학회지
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• 제10권4호
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• pp.54-60
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• 2006

본 연구에서는 실험을 통하여 획득한 데이터로부터 유전 알고리즘(Genetic Algorithms)과 스케일링기법(Scaling Method)을 이용한 하이브리드 기법(Hybrid Method)으로 압축기 성능선도를 생성하는 방법을 제안하였다. 기 수행한 연구에서 유전 알고리즘만 이용할 경우 압축기 성능선도 생성 시 서지점들과 쵸크점들을 예측하는데 불분명한 단점이 있어 기존의 구성품 성능선도 생성에 널리 사용하는 스케일링 기법을 보완적으로 이용하여 보다 정확한 압축기 성능선도를 생성하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.460-463
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• 2000

Fuzzy logic control(FLC) has been studied extensively and has been applied in various applications. The most popular control strategy takes the Fuzzy Proportional-Integral(FPI) form while systematic methods have been developed to derive the fuzzy rules and membership functions the choice of the scaling factors remains an open problem, In this paper an analytical FPI scaling factor determining method is derived based on the functional equivalence of the PI and FPI controllers. Simulation have been carried out with a brushless DC motor drive system as test-bed the obtained results drive system as test-bed the obtained results have verified that the derived method is applicable to both the initial choice and further tuning of the FPI scaling factors.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 춘계종합학술대회
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• pp.275-278
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• 2002

MOSFET의 게이트 길이가 50nm이하로 작아지면 소자를 설계함에 있어 고려해야 하는 많은 문제점들이 존재하게 된다. 본 논문에서는 MOSFET 소자에 대한 문턱 전압 특성을 조사하였다. 소자에 대한 스케일링은 generalized scaling을 사용하였고 게이트 길이 100nm에서 30nm까지 시뮬레이션 하였다. 이때 나노 구조 MOSFET에 대한 스케일링의 한계를 볼 수 있었다. 문턱 전압을 구하는 방법으로는 선형 추출 방법을 사용하였다.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2011년도 정기 학술발표대회
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• pp.91-91
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• 2011

The quality of the surface layer in concrete structures plays an important role in the durability of the concrete. The concrete factory products are made as they improve the appearance of the surface and compressive strength in need. A common criterion to judge the quality of concrete products frequently seen in our daily life appears to be "beauty" in terms of consistent shaping. However, as for most concrete curb in such areas where a large amount of anti-freezing agents(NaCl) and ice and snow melting agents(CaCl2) are spread over roads to ensure road safety during the winter season, since deterioration advances from the surface, scaling is seen on the surface concrete due to deterioration which combined freezing damage and salt damage. Especially, In cold northern districts, the spreading amount of deicing salts increases by regulation of studded tire use, and the scaling of the concrete products, the various parts of concrete structures for roads is increasing in recent years. In this study, L-shape concrete curb were targeted, the permeable form method with the commercial permeable sheet was applied to it and the improvements of the quality were examined. By the permeable form method, surface layers got strengthened, which prevented permeation of the deterioration factor from the outside, and the scaling resistance of the upper surface where the permeable sheet was applied improved exceedingly. It will be expected by applying the permeable form method to various concrete products that frost resistance improves and scaling damage decreases.

• 한국통신학회논문지
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• 제33권7B호
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• pp.592-600
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• 2008

In this paper, a Hybrid Scaling based DTW (HS-DTW) mechanism is proposed for detection of periodic shrew TCP attacks. A low-rate TCP attack which is a type of shrew DoS (Denial of Service) attacks, was reported recently, but it is difficult to detect the attack using previous flooding DoS detection mechanisms. A pattern matching method with DTW (Dynamic Time Warping) as a type of defense mechanisms was shown to be reasonable method of detecting and defending against a periodic low-rate TCP attack in an input traffic link. This method, however, has the problem that a legitimate link may be misidentified as an attack link, if the threshold of the DTW value is not reasonable. In order to effectively discriminate between attack traffic and legitimate traffic, the difference between their DTW values should be large as possible. To increase the difference, we analyze a critical problem with a previous algorithm and introduce a scaling method that increases the difference between DTW values. Four kinds of scaling methods are considered and the standard deviation of the sampling data is adopted. We can select an appropriate scaling scheme according to the standard deviation of an input signal. This is why the HS-DTW increases the difference between DTW values of legitimate and attack traffic. The result is that the determination of the threshold value for discrimination is easier and the probability of mistaking legitimate traffic for an attack is dramatically reduced.

• 한국수자원학회논문집
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• 제46권6호
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• pp.585-596
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• 2013

본 연구에서는 기후변화에 따른 수자원 영향평가를 위한 지역기후모형과 단계적 스케일링기법을 연계한 혼합상세화기법을 개발하고 그에 따른 적용성을 평가하고자 하였다. 단계적 스케일링기법은 강수량 구간을 총 3구간(극치호우사상, 무강수일수, 기타)으로 나누어 각 구간에 따라 각기 다른 방법을 적용하여 보정하는 기법으로, 극치호우사상은 회귀식을 이용한 보정기법, 무강수일수는 분위사상법, 나머지 부분은 평균 및 분산보정 기법을 적용하였다. 이 기법의 비교 평가를 위해 최근 혼합 상세화기법으로 가장 많이 적용되고 있는 선형보정기법, 분위사상법, 일기상발생기법을 활용하여 기상청 관할 기상관측소 61개 지점을 대상으로 적용성 평가를 수행하였다. 평가 결과, RCM에서 생산된 원자료 및 3가지 기존 기법(선형보정기법, 분위사상법, 일기상발생기법)으로 보정된 기후시나리오에 비해 본 연구에서 제안한 단계적 스케일링기법이 실제 기후특성을 잘 모의하는 것으로 나타나 적용성이 우수한 것으로 판단된다. 이러한 연구결과를 통해 단계적 스케일링기법은 RCM 사용이 증대될 기후변화 연구에 있어 그 활용성이 높을 것으로 기대된다.

• Structural Engineering and Mechanics
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• 제14권3호
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• pp.345-364
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• 2002

The scaling laws for vibration response of anti-symmetrically laminated plates are derived by applying the similitude transformation to the governing differential equations directly. With this approach, a closed-form solution of the governing equations is not required. This is a significant advantage over the method employed by other researchers where similitude transformation is applied to the closed-form solution. The scaling laws are tested by comparing the similitude fundamental frequencies to the theoretical fundamental frequencies determined from the available closed-form solutions. In case of complete similitude, similitude solutions from the scaling laws exactly agree with the theoretical solutions. Sometimes, it may not be feasible to select the model which obeys the similarity requirement completely, therefore partial similitude is theoretically investigated and approximate scaling laws are recommended. The distorted models in stacking sequences and laminated material properties demonstrate reasonable accuracy. On the contrary, a model with distortion in fiber angle is not recommended. The derived scaling laws are very useful to determine the vibration response of complex prototypes by performing the experiment on a model with required similarities.

• International Journal of Fluid Machinery and Systems
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• 제3권4호
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• pp.279-284
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• 2010

Tip clearance losses occur in every turbomachine. To estimate the losses in efficiency it is important to understand the mechanism of this secondary flow. Tip clearance losses are mainly caused by a spiral vortex formed on the suction side of the blade of a turbomachine, which induces a drag and also has an influence on the incident flow of the blades. In this paper a physical based scaling method is developed out of an analytical ansatz for the tip clearance losses. This scaling method is validated by measurements on an axial fan with five different tip clearances.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2268-2271
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• 1998

This paper proposes a method which can resolve the problem of existing fuzzy Pl controller using optimal scaling gains obtained by genetic algorithm. The new method adapt a fuzzy logic controller as a high level controller to perform scaling gain algorithm between two pre-determined sets.

• 대한전기학회논문지
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• 제43권5호
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• pp.819-826
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• 1994

This paper deals with a self-tuning fuzzy controller. The fuzzy controller is constructed with linguistic rules which consist of the fuzzy sets. Each fuzzy set is characterized by a membership function. The tuning fuzzy controller has paramenters that are input/output scaling factors to effect control output. In this paper we propose a tuning method for the scaling factor Computer simulations carried out on first-order and second-order processes will show how the present tuning approach improves the transient and the steady-state characteristics of the overall system.The applicability of the proposed algorithm is certified by computer simulation results.