• 제어로봇시스템학회논문지
• /
• 제2권3호
• /
• pp.165-173
• /
• 1996

It is not desirable to have too large control input in control systems, because there are usually a limitation for the input magnitude and cost for the input energy. Previous papers in the iterative learning control did not considered on these points. In this paper, an iterative learning control method is proposed for a class of nonlinear systems with consideration on input magnitude by adopting a concept of cost function consisting of the output error and the input magnitude in quadratic form. We proposed a new input update law with an input penalty function. If we choose a reasonable input penalty function, the two control objectives, good command following and small input energy, can be achieved. The characteristics of the proposed method are shown in the simulation examples.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 1999년도 학술대회논문집-국제 전기방전 및 플라즈마 심포지엄 Proceedings of 1999 KIIEE Annual Conference-International Symposium of Electrical Discharge and Plasma
• /
• pp.127-131
• /
• 1999

In this paper, using a wide-band AE sensor with the frequency range from 100[kHz], the frequency spectra of AE signals generated from the corona discharges of the needle-plane electrode was analyzed to determine the proper ultrasonic sensor. We also examined the relationship between the magnitude of corona discharge and the magnitude of AE signals in peak-to-peak value under the application of 60[Hz] AC high-voltage in oil. From these results, the main frequency spectra of AE signals emitted from the corona discharges of the needle-plane gap were found to be 130[kHz] by the fast fourier transform. The magnitude of AE signals was proportional to the magnitude of corona discharge and discharge current pulse with increasing the applied voltages. Also the detection of corona discharge point location by AE signals was found to be possible by using two sensors.

• 한국생산제조학회지
• /
• 제7권3호
• /
• pp.68-78
• /
• 1998

Welding structure contains residual stress due to thermal-plastic strain during welding process, and its magnitude and distribution depend on welding conditions. Cracks initiate from various defects of the weldment, propagate and lead to final fracture, The crack initiation and propagation processes are affected by the magnitude and distribution. Therefore, the magnitude and distribution of weldment residual stress should be considered for safety design and service of welding structures. Also it is very important that more accurate assessment method of fatigue crack growth must take into account the redistributing the residual stress quantitively. because the residual stress in weldment has characteristics of its redistribution with loading magnitude, number of cycles and fatigue crack propagation. In this study fatigue crack behavior of STS-304 weldment was investigated during crack propagation into tensile residual stress region or compressive residual stress region. Crack growth rates were predicted and compared with experimental results.

• 자원환경지질
• /
• 제34권6호
• /
• pp.573-581
• /
• 2001

110 earthquake parameters (origin time, epicentral location and magnitude) were determined from 533 event records between 1905 and 1942 using data mainly from the "Annual Report of the Meteorological Observatory of the Government General of Tyosen" We adopted epicentral coordinates from the original reports for 34 events and from the Japanese Central Meteorological Observatory far another .34 events. We determined epicenters for 37 events using arrival time information from the reports. We adopted 4 epicenters from the International Seismological Summary and I from the Chinese bulletin. To determine the magnitude, we applied Tsuboi (1954) formula which is currently employed by Korea Meteorological Administration (KMA) for 94 events. For 16 events, we determined magnitude from the reef)reed felt epicentral areal using the correlation equation between known magnitude and felt area.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 2008년도 추계학술대회
• /
• pp.143-146
• /
• 2008

The objectives of this study were to evaluate color sensation for yellowish natural dye fabrics using magnitude estimation to determine physical colorimetric factors significantly related to human sensibility by establishing power function in psychophysical analysis. Fourteen different yellowish fabrics dyed with natural colorants were selected as stimuli and subjective color sensations including brightness, heaviness, softness, strength, warmth, activeness, classicalness, femininity, and pleasantness for each stimulus were evaluated. As results, yellowish natural dye fabrics in general seemed to evoke feeling of brightness, femininity, and pleasantness more strongly than that of heaviness and classicalness. Most of color sensation were significantly related with more than one of physical color properties, which leads to establishing reliable power functions between them. In the power functions, these relationships could be utilized to design color-sensible natural dye textiles.

• 방송공학회논문지
• /
• 제26권7호
• /
• pp.862-867
• /
• 2021

Although Deep Neural Networks (DNNs) have shown remarkable performance in various artificial intelligence fields, it is well known that DNNs are vulnerable to adversarial attacks. Since adversarial attacks are implemented by adding perturbations onto benign examples, increasing the sparsity of DNNs minimizes the propagation of errors to high-level layers. In this paper, unlike the traditional pruning scheme removing low magnitude weights, we eliminate high magnitude weights that are usually considered high absolute values, named 'reverse pruning' to ensure robustness. By conducting both theoretical and experimental analyses, we observe that reverse pruning ensures the robustness of DNNs. Experimental results show that our reverse pruning outperforms previous work with 29.01% in Top-1 accuracy on perturbed CIFAR-10. However, reverse pruning does not guarantee benign samples. To relax this problem, we further conducted experiments by adding a regularization term for the high magnitude weights. With adding the regularization term, we also applied conventional pruning to ensure the robustness of DNNs.

• 한국과학교육학회지
• /
• 제23권3호
• /
• pp.229-238
• /
• 2003

일상적인 경험을 바탕으로 중학생들이 도구를 사용하지 않고 물리량의 치수를 어림하는 능력을 조사하였다. 이를 위하여 연구자들은 기본량에 해당하는 길이와 질량, 유도량에 해당하는 속력, 부피, 밀도에 대한 차수 어림 능력을 묻는 선택형 문항을 개발하였고, 서울지역 중학교 1학년과 3학년 학생 448명이 조사에 참가하였다. 전체적으로 반 이상의 학생들이 물리량의 치수를 참값과 다르게 어림하고 있었는데, 차원이 복잡한 유도량이거나 크기가 작을수록 차수 어림 능력이 낮아졌다. 학년에 따른 차이는 크지 않았으나 성별에 따라서 차수 어림 능력에 차이가 있었고 상대적으로 남학생이 길이 어림을 잘 하였다. 결론적으로 반수 이상의 학생들이 물리량이 차수를 제대로 어림하지 못한다는 점은 물리량과 단위에 대한 정성적인 이해가 부족함을 나타내며, 기능적인 측면을 강조하는 측정 교육이 가지는 한계점을 보여주었다. 따라서 실제 측정을 통하여 구한 물리량의 정성적인 의미를 이해할 수 있도록 하기 위하여 어림 교육이 필요함을 시사하고 있다.

• 한국정밀공학회지
• /
• 제17권10호
• /
• pp.186-191
• /
• 2000

We use so many plastic products in everyday. Because polymer materials have a lot of merits including low cost and easiness of forming, they are widely using at many manufacturing industries. Microcellular foaming process appeared at MIT in 1980's to save a quantity of material and increase mechanical properties. The information about the thickness of cavity plays an important role in appling microcellular foaming process to the conventional injection molding process. It is essential to make an effective foam. The goal of this research is to measure the relation between the change of cavity's thickness and foaming magnitude made after inserting a gas. R/t is a conception that indicate proportion between radius and thickness of cavity in mold system. By means of SEM observation of side surface of cavity sample, foaming magnitude of cavity is mold system. By means of SEM observation of side surface of cavity sample, foaming magnitude of polymer in microcellular foaming process is decreasing gradually as the value of R/t is increasing. The proposed foaming magnitude changes data of polymer in relation to mold system can be applied in more extensive injection molding process, such as optimum design of mold for microcellular foaming process.

• 한국지반신소재학회논문집
• /
• 제16권2호
• /
• pp.79-87
• /
• 2017

본 연구에서는 2006년부터 2013년 까지 강원도 영서 인근 지역의 토석류 피해지역 43개소에 대한 현장조사 결과를 바탕으로 토석류 규모를 산정하고 영향인자가 토석류 규모에 미치는 상관성 분석을 실시하였다. 토석류의 규모는 발생지역별로 큰 차이를 보이나 계곡형이 사면형보다 약 6.5배 큰 것으로 조사되었으며 계곡형 발생부의 토석류 규모는 전체의 약 5% 정도의 규모인 것을 확인하였다. 침식률은 계곡형에서 전체 토석류 발생량이 $10,000m^3$ 보다 큰 대규모인 경우 $19m^3/m$, $10,000m^3$ 보다 작은 경우 $8m^3/m$의 값을 갖고, 사면형은 $5m^3/m$로 산정되었다. 토석류 규모의 영향인자에 대한 상관성 분석결과, 토석류 유하부의 길이와 폭은 상관성이 높은 것으로 나타났으며, 평균경사와 침식 깊이는 상관성이 낮은 것으로 나타났다. 특히, 침식깊이는 규모와 상관성 없이 0.5~2.6m의 범위로 Ikeya(1981)가 제안한 값과 유사하였다. 연속강우량, 최대시간강우량 등 토석류 유발강우와 토석류 규모는 상관성이 낮은 것으로 분석되었다.

• 한국콘텐츠학회논문지
• /
• 제22권4호
• /
• pp.352-364
• /
• 2022

환경 개선을 위한 행동의 종류와 요구되는 수준이 다양화되면서 효과적 환경 메시지 개발의 필요성도 늘어나고 있다. 본 연구는 요구 수준이 다른 유형의 행동에 적합한 메시지를 개발하기 위해 메시지 특성인 메시지 프레이밍과 가치지향성을 활용하여 2(메시지 프레이밍: 이익/손실) × 2(가치지향성: 개인/사회) × 2(예방 행동 요구 수준: 높음/낮음) 실험을 실시하였다. 분석 결과, 프레이밍과 행동 요구 수준은 메시지 태도와 행동의도에 주효과를 보였다. 손실 프레이밍보다 이익 프레이밍에서 호의적인 효과가 나타났고, 행동 요구 수준이 낮을 경우 높은 설득 효과가 나타났다. 상호작용 분석 결과, 개인지향 메시지에서는 이익 프레이밍의 행동 의도가 높았고, 사회지향 메시지에서는 프레이밍 간의 차이가 없었다. 또, 행동 요구 수준이 낮을 경우, 개인지향 메시지에서 이익 프레이밍의 메시지 태도가 손실 프레이밍보다 호의적으로 나타났다. 반면 행동 요구 수준이 높을 경우, 사회지향 메시지에서 이익 프레이밍의 메시지 태도가 손실 프레이밍보다 호의적으로 나타났다. 행동 요구 수준에 따른 상호작용 형태의 차이는 있었으나, 개인지향 이익 프레이밍 메시지가 가장 효과적으로 나타났다.