• Computers and Concrete
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• 제7권5호
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• pp.455-468
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• 2010

This paper presents a prediction and simulation method of tensile stress-strain curves of Engineered Cementitious Composites (ECC). For this purpose, the bridging stress and crack opening relations were obtained by the fiber bridging constitutive law which is quantitatively able to consider the fiber distribution characteristics. And then, a multi-linear model is employed for a simplification of the bridging stress and crack opening relation. In addition, to account the variability of material properties, randomly distributed properties drawn from a normal distribution with 95% confidence are assigned to each element which is determined on the basis of crack spacing. To consider the variation of crack spacing, randomly distributed crack spacing is drawn from the probability density function of fiber inclined angle calculated based on sectional image analysis. An equation for calculation of the crack spacing that takes into quantitative consideration the dimensions and fiber distribution was also derived. Subsequently, a series of simulations of ECC tensile stress-strain curves was performed. The simulation results exhibit obvious strain hardening behavior associated with multiple cracking, which correspond well with test results.

• 성인간호학회지
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• 제21권2호
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• pp.179-186
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• 2009

Purpose: The purpose of this study was to examine the effects of hand massage on fatigue, sleep satisfaction and blood pressure of the aged in a long-term care facility. Methods: The data were collected from June to August 2008. The subjects were randomly recruited from a long-term care facility in Junnam Providence and were randomly assigned to the experimental group (n=22) or control group (n=22). Hand massage was carried out every other day in the evening for two weeks. Massage was administered to each forearm and hand for 10 minutes. Descriptive statistics, $x^2$-test and t-test were performed using SAS program. Results: In the experimental group, the fatigue (p=.017) was significantly lower and the sleep satisfaction (p=.043) was significantly higher than for the control group. Conclusion: On the basis of the results of the study, hand massage can be recommended for the elderly with sleep disturbance to reduce fatigue.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2397-2404
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• 2011

Variable selection k nearest neighbor QSAR modeling approach was applied to a data set of 80 3-arylisoquinolines exhibiting cytotoxicity against human lung tumor cell line (A-549). All compounds were characterized with molecular topology descriptors calculated with the MolconnZ program. Seven compounds were randomly selected from the original dataset and used as an external validation set. The remaining subset of 73 compounds was divided into multiple training (56 to 61 compounds) and test (17 to 12 compounds) sets using a chemical diversity sampling method developed in this group. Highly predictive models characterized by the leave-one out cross-validated $R^2$ ($q^2$) values greater than 0.8 for the training sets and $R^2$ values greater than 0.7 for the test sets have been obtained. The robustness of models was confirmed by the Y-randomization test: all models built using training sets with randomly shuffled activities were characterized by low $q^2{\leq}0.26$ and $R^2{\leq}0.22$ for training and test sets, respectively. Twelve best models (with the highest values of both $q^2$ and $R^2$) predicted the activities of the external validation set of seven compounds with $R^2$ ranging from 0.71 to 0.93.

• 대한전자공학회논문지SD
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• 제37권4호
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• pp.71-79
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• 2000

기존의 March 알고리즘으로는 내장된 메모리의 CMOS ADOFs(Address Decoder Open Faults)를 점검할 수 없다. 번지 생성 순서 및 데이터 생성을 달리 할 수 있다는 자유도(DOF: Degree of Freedom)에 근거한 수정된 March 알고리즘이 제안되었다. 본 논문에서는 번지생성기로 완전 CA(Cellular Automata)를, 데이터 생성기로 Rl-LFSRs(Randomly Inversed LFSRs)을 사용하여 수정된 March 알고리즘을 개선하였다. 본 알고리즘은 기존의 March 알고리즘에서 점검할 수 있었던 SAF, ADF, CF, TF, 및 CMOS ADOF의 완점점검은 물론, NPSFs(Neighborhood Pattern Sensitive Faults)도 추가로 점검할 수 있으며, 알고리즘의 복잡도는 O(n)을 유지한다.

• Journal of Forest and Environmental Science
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• 제25권1호
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• pp.57-65
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• 2009

Ficus deltoidea Jack is an important and popular medicinal plant species found in the Malaysia. Plants are being collected and used based on morphology and authentication to prevent adulteration is not in practice. In this study, twenty-six accessions of F. deltoidea Jack were collected from Kelantan and Terengganu states of Peninsular Malaysia to examine their genetic similarities and differences using randomly amplified polymorphic DNA (RAPD) technique. Out of 20 arbitrary primers, two primers (D-10 and D-11) were selected which produced reliable DNA polymorphism. D-10 and D-11 primers generated 138 RAPD bands ranging from 250 bp to 3000 bp. Ninety-nine of them were polymorphic loci (72%) and thirty-nine were nonpolymorphic loci (28%). A total of 56 bands with polymorphic loci were amplified with primer D-10 and analyzed by cluster analysis and UPGMA to present a dendrogram depicting the degree of genetic relationship among 26 accessions. Eight RAPD markers were sequenced to determine their identity. RAPD analysis showed the genetic diversity among 26 accessions of F. deltoidea Jack. The RAPD profile and RAPD marker sequences reported in this paper could be used in plant and/or plant material authentication. This study also suggested that RAPD can be a useful technique to study DNA polymorphism in F. deltoidea Jack.

• 대한기계학회논문집A
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• 제30권3호
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• pp.260-268
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• 2006

The micromechanical approach was used to investigate the interfacial strain distributions of a unidirectional composite under transverse loading in which fibers were usually found to be randomly packed. Representative volume elements (RVE) for the analysis were composed of both regular fiber arrays such as a square array and a hexagonal array, and a random fiber array. The finite element analysis was performed to analyze the normal, tangential and shear strains at the interface. Due to the periodic characteristics of the strain distributions at the interface, the Fourier series approximation with proper coefficients was utilized to evaluate the strain distributions at the interface for the regular and random fiber arrays with respect to fiber volume fractions. From the analysis, it was found that the random arrangement of fibers had a significant influence on the strain distribution at the interface, and the strain distribution in the regular fiber arrays was one of special cases of that in the random fiber array.

• Asian-Australasian Journal of Animal Sciences
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• 제9권2호
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• pp.123-126
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• 1996

Sixteen Harnai males were used to evaluate the influence of varying levels of fourwing saltbush hay on feed and water intakes as well as the blood serum mineral status in a completely randomized design. The animals were grouped randomly into four, with four animals in each. The four groups were randomly allotted low, medium, high and very high levels of saltbush hay supplementation in addition to wheat straw. The animals were given fresh water at free of choice. Weekly body weight was recorded for each individual animal. Blood serum was collected for mineral contents. The experiment lasted for eight weeks. The inclusion of saltbush leaves in the diet showed a non-significant effect on the total dry matter intake. There has been a significant increase in the water intake when very high levels of saltbush were included in the ration. Lower levels showed no effect on the water intake. The animals maintained their body weight from week 1 to week 8. No treatment by weeks interactions on the potassium and sodium levels were detected. However higher levels of saltbush increased significantly the potassium and sodium contents in the serum. Calcium contents were significantly(p<0.01) lowered with the inclusion of saltbush leaves in the diet. Whereas Phosphorous contents showed an increasing(p<0.05) trend with the higher levels of saltbush. No clinical or sub-clinical toxicological symptoms were observed in the sheep with the higher mineral contents.

• 한국산학기술학회논문지
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• 제13권1호
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• pp.343-347
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• 2012

결정 궤환 구조를 사용한 비선형 등화기법은 열악한 채널환경에서 발생하는 심각한 심볼간 간섭을 제거하는데 크게 요구되고 있다. 이 논문에서는 정보 이론적 학습방법과 랜덤 심볼에 기본을 두고 개발된 선형 자력 등화 알고리듬에 이 결정 궤환 구조를 적용한다. 제안된 결정 궤환 자력 등화기는 송신 심볼이 가지는 확률밀도함수와 동일한 모양을 갖도록 랜덤 심볼이 생성된다. 이 랜덤 심볼의 확률밀도함수와 등화기 출력이 가지는 확률밀도함수의 차이를 최소화함으로써 제안된 자력 등화 알고리듬은 등화된 출력 신호를 만들어낸다. 시뮬레이션 결과로부터 선형 알고리듬에 비해 향상된 수렴성능 및 오차 성능을 나타냈다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.106-111
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• 2002

In this paper, a new three phase RPWM(Random PWM)with fixed switching frequency is proposed. In the proposed RPWM, each of three phase pulses is located randomly in each switching interval. Based on the space vector modulation technique, the duty ratio of the pulses is calculated. Along with the the randomization of the PWM pulses, we can obtain the effects of spread spectra of voltage, current as in the case of randomly changed switching frequency. To verify the validity of the proposed RPWM, the experimental study was tried. Along with the randomization of PWM pulses, the space vector modulation is also executed in the C167 micro-controller. The experimental results show that the voltage and current harmonics are spread to a wide band area and that the audible acoustic noise is reduced by the proposed RPWM method.

• 한국지능시스템학회논문지
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• 제19권3호
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• pp.311-316
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• 2009

본 논문에서는 파티클 필터(Particle Filter)를 사용한 모바일 감시 로봇을 위한 실시간 움직임 추정 알고리즘을 제안한다. 파티클 필터는 몬테카를로(Monte Carlo) 샘플링 방법을 기반으로 사전분포확률(Prior distribution probability)와 사후분포확률(Posterior distribution probability)을 가지는 베이지안 조건 확률 모델(Bayesian conditional probabilities model)을 사용하는 방법이다. 그러나 대부분의 파티클 필터에서는 초기 확률밀도(Prior probability density)를 임의로 정의하여 사용하지만, 본 논문에서는 Sum of Absolute Difference (SAD)를 이용하여 초기 확률밀도를 구하고, 이를 파티클 필터에 적용하여 모바일 감시 로봇 환경에서 임의로 움직이는 물체를 강인하게 실시간으로 추정하고 추적하는 시스템을 구현하였다.