• Journal of Communications and Networks
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• v.10 no.2
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• pp.213-220
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• 2008

This paper analyzes a broadcasting technique for wireless multi-hop sensor networks that uses a form of cooperative diversity called opportunistic large arrays (OLAs). We propose a method for autonomous scheduling of the nodes, which limits the nodes that relay and saves as much as 32% of the transmit energy compared to other broadcast approaches, without requiring global positioning system (GPS), individual node addressing, or inter-node interaction. This energy-saving is a result of cross-layer interaction, in the sense that the medium access control (MAC) and routing functions are partially executed in the physical (PHY) layer. Our proposed method is called OLA with a transmission threshold (OLA-T), where a node compares its received power to a threshold to decide if it should forward. We also investigate OLA with variable threshold (OLA-VT), which optimizes the thresholds as a function of level. OLA-T and OLA-VT are compared with OLA broadcasting without a transmission threshold, each in their minimum energy configuration, using an analytical method under the orthogonal and continuum assumptions. The trade-off between the number of OLA levels (or hops) required to achieve successful network broadcast and transmission energy saved is investigated. The results based on the analytical assumptions are confirmed with Monte Carlo simulations.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.1
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• pp.43-50
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• 2013

Palmitic acid (PAM), one of the most common saturated fatty acid (SFA) in animals and plants, has been shown to induce apoptosis in exocrine pancreatic AR42J cells. In this study, we investigated cellular mechanisms underlying protective effects of oleic acid (OLA) against the lipotoxic actions of PAM in AR42J cells. Exposure of cells to long-chain SFA induced apoptotic cell death determined by MTT cell viability assay and Hoechst staining. Co-treatment of OLA with PAM markedly protected cells against PAM-induced apoptosis. OLA significantly attenuated the PAM-induced increase in the levels of pro-apoptotic Bak protein, cleaved forms of apoptotic proteins (caspase-3, PARP). On the contrary, OLA restored the decreased levels of anti-apoptotic Bcl-2 family proteins (Bcl-2, Bcl-xL, and Mcl-1) in PAM-treated cells. OLA also induced up-regulation of the mRNA expression of Dgat2 and Cpt1 genes which are involved in triacylglycerol (TAG) synthesis and mitochondrial ${\beta}$-oxidation, respectively. Intracellular TAG accumulation was increased by OLA supplementation in accordance with enhanced expression of Dgat2 gene. These results indicate that restoration of anti-apoptotic/pro-apop-totic protein balance from apoptosis toward cell survival is involved in the cytoprotective effects of OLA against PAM-induced apoptosis in pancreatic AR42J cells. In addition, OLA-induced increase in TAG accumulation and up-regulation of Dgat2 and Cpt1 gene expressions may be possibly associated in part with the ability of OLA to protect cells from deleterious actions of PAM.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.559-568
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• 2007

Recently, copy number variations (CNV) of genes or genomic segments have been intensively studied and various analysis methods have been developed. In this study, quantitative oligonucleotide ligation assay (qOLA) was applied to investigate CNV of KIT gene in the Landrace breed. A combined assay using qOLA and pyrosequencing, 6 genotype classes, I1/I1 or I3/i (IBe), I1/I2 or I3/IP, I1/I3, I1/IP or I2/i (IBe), I2/I2and I2/IP, were identified from 44 Landrace pigs. Genotype assignment using grouping features of measurements on a scatter plot showed 100% agreement with those using a statistical assignment by PROC FASTCLUS procedure implemented in the SAS package. Two versions (3100 and 3130) of ABI sequencers gave the same genotyping results, indicating there was no influence on qOLA by different versions of instrument, however, the means of standard deviation and coefficient of variation from the qOLA on a ABI 3130 (2.33 and 4.10) was lower than those from the qOLA on a ABI 3100 (2.67 and 4.81). Effect of proteinase K treatment on the PCR product followed by qOLA was very clear because noise peaks were disappeared and the observed ration fit better to the reference ratio corresponding to each genotype.

• 보존과학연구
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• s.33
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• pp.5-17
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• 2012

An Ola leaf manuscript, which consists of words carved on an Ola leaf and is filled up with a mixture of herbal oils made from Vateria acuminata Hyne and charcoal, is one of the native writing media in Sri Lanka. According to historical records, Ola leaf manuscripts had been used from the 1st to the 18th century A.D. From the recent findings that Ola leaf manuscripts have been preserved well for the past 400 years and are in good state of preservation, it is supposed that herbal oils preserve Ola leaves against environmental and biological factors such as fungi and insects. To evaluate the anti-biological susceptibility of the herbal oils, the molds isolated from wooden printing blocks in Janggyeong Panjeon of Haeinsa Temple in South Korea and bacteria and fungi isolated from Ola leaves were cultured. After spreading the microorganisms suspension on an agar plate, a disk paper containing a certain volume of herbal oil was placed on the agar plate. It was found in the experiment that herbal oil exhibits a clear zone, which is optically clear and inhibits the growth of microorganisms, against some molds and bacteria. The study results indicate that the herbal oil from the plant Vateria acuminata Hyne has the anti-bacterial and anti-fungal properties.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.6
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• pp.356-367
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• 2019

This study evaluates the variation characteristics of irregular wave fields for two-dimensional Low-Crested Structure (LCS) by olaFlow model based on the two-phases flow by numerical analysis. The numerical results of olaFlow model are verified by comparing irregular wave profile of target wave spectrum and measured one, and their spectra. In addition, spacial variation of irregular wave spectrum, wave transmission ratio, root-mean square wave height, time-averaged velocity and time-averaged turbulent kinetic energy by two-dimensional LCS are discussed numerically. The time-averaged velocity, one of the most important numerical results is formed counterclockwise circulating cell and clockwise nearshore current on the front of LCS, and strong uni-directional flow directing onshore side around still water level.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.6
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• pp.270-285
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• 2018

The behavior of wave-induced pore water pressure inside the rubble mound and seabed, and the resultant structure failure are investigated, which are used in design of the composite breakwater representing the coastal and harbor structures. Numerical simulation techniques have been widely used to assess these behaviors through linear and nonlinear methods in many researches. While the combination of strongly nonlinear analytical method and turbulence model have not been applied yet, which can simulate these characteristics more accurately. In this study, olaFlow model considering the wave-breaking and turbulent phenomena is applied through VOF and LES methods, which gives more exact solution by using the multiphase flow analytical method. The verification of olaFlow model is demonstrated by comparing the experimental and numerical results for the interactions of regular waves-seabed and regular waves-composite breakwater-seabed. The characteristics of the spatial distributions of horizontal wave pressure, excess-pore-water pressure, mean flow velocity and mean vorticity on the upright caisson, and inside the rubble mound and seabed are discussed, as well as the relation between the mean distribution of vorticity size and mean turbulent kinetic energy. And the stability of composite breakwater are also discussed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.4
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• pp.153-165
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• 2018

In this study, the performance of irregular wave field generation of olaFlow is first verified by comparing the frequency spectrum of the generated waves by the wave-source using olaFlow and the target wave. Based on the wave performance of irregular waves of olaFlow, the characteristics of the velocity field including the average flow velocity, longshore current and turbulent kinetic energy around the three-dimensional permeable submerged breakwaters, which act as the main external forces of the salient formation, are numerically investigated. The numerical results show that as the gap width between breakwaters decreases, the wave height in the center of the gap increases and as the gap width between breakwaters increases, the longshore currents become stronger. As a result, it is possible to understand the formation of the salient formed behind the submerged breakwaters.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.4
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• pp.199-208
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• 2019

Regular waves were generated in a wave flume under perfect reflection condition to evaluate performance of three CFD models of CADMAS-SURF, olaFlow, and KIOSTFOAM. The experiments and numerical simulations were carried out for three different conditions of non-breaking, breaking of standing waves, and breaking of incident waves. Among the three CFD models, KIOSTFOAM showed best performance in reproducing the experimental results. Although the run time was reduced by using CADMAS-SURF, its computational accuracy was worse than KIOSTFOAM. olaFlow was the fastest model, but active wave absorption at the wave generation boundary was not satisfactory. In addition, the model excessively dissipated wave energy when wave breaking occurred.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.226-228
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• 2000

최근 제안된 관찰학습(OLA: Observational Learning Algorithm)은 committee를 구성하는 각각의 학습 모델들이 다른 학습 모델들을 관찰함으로써 얻어진 가상데이터를 실제 데이터와 결합시켜 학습에 이용하는 방법이다. 본 논문에서는, UCI 데이터 셋의 분류(classification)와 예측(regression)문제에 대하여 다층 퍼셉트론을 학습 모델로 설정하고, 이에 대하여 OLA와 bagging, boosting의 성능을 비교, 분석하였다.

• Proceedings of the KAIS Fall Conference
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• 2004.11a
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• pp.114-117
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• 2004

본 논문에서는 합성에 의한 분석(Analysis-by-Synthesis) 및 가산중첩(Overlap-Add) 방식을 채택하고 있는 음성신호의 AbS/OLA 정현파 모델에 웨이블릿 변환을 적용한 새로운 모델을 제안하였다. 즉, 기존의 모델에 웨이블릿 변환을 적용하여 입력신호를 몇 개의 부대역 신호로 나눈 다음 각각 다른 길이의 분석 윈도우를 적용한다. 이는 기존 모델의 정현파 파라미터 추출 시 고정된 길이의 분석 윈도우를 이용하는 단점을 극복하여 좀 더 정확한 파라미터 추출을 가능하게 한다. 시험결과 제안된 정현파 모델이 기존 모델에 비해 합성음의 스펙트럼 및 위상 특성, 음질 등에서 성능이 개선됨을 확인할 수 있었다.