• Communications for Statistical Applications and Methods
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• 제29권3호
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• pp.373-391
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• 2022

The distribution of observations in most econometric studies with spatial heterogeneity is skewed. Usually, a single transformation of the data is used to approximate normality and to model the transformed data with a normal assumption. This assumption is however not always appropriate due to the fact that panel data often exhibit non-normal characteristics. In this work, the normality assumption is relaxed in spatial mixed models, allowing for spatial heterogeneity. An inference procedure based on Bayesian mixed modeling is carried out with a multivariate skew-elliptical distribution, which includes the skew-t, skew-normal, student-t, and normal distributions as special cases. The methodology is illustrated through a simulation study and according to the empirical literature, we fit our models to non-life insurance consumption observed between 1998 and 2002 across a spatial panel of 103 Italian provinces in order to determine its determinants. Analyzing the posterior distribution of some parameters and comparing various model comparison criteria indicate the proposed model to be superior to conventional ones.

• Asia Marketing Journal
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• 제20권1호
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• pp.49-68
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• 2018

It is appropriate and useful to interpret some product classification schemes as buyer behavior models; such classifications permit investigations of discrepancies between classification predictions and actual buyer behavior. We review existing product classifications and identify underlying behavioral assumptions of various classification schemes that have been used in the marketing discipline for more than nine decades. Recognizing the irrelevance of existing product classifications for current products, we propose a new reclassification framework by incorporating transparency concepts. Based on this extended product classification, we highlight the potential roles of product classification study as an important link between consumer research and marketing strategy, emphasizing behavioral implications.

• International Journal of Korean Welding Society
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• 제2권2호
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• pp.32-35
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• 2002

In this paper, an intelligent system to determine welding parameters for each pass and welding position in pipeline welding based on one database and FEM model, two BP neural network models and a C-NN model was developed and validated. The preliminary test of the system has indicated that the developed system could determine welding parameters fur pipeline welding quickly, from which good weldments can be produced without experienced welding personnel. Experiments using the predicted welding parameters from the developed system proved the feasibility of interface standards and intelligent control technology to increase productivity, improve quality, and reduce the cost of system integration.

• Ocean Systems Engineering
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• 제13권2호
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• pp.97-121
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• 2023

Through-the-thickness stress distribution in a tubular member has a profound effect on the fatigue behavior of tubular joints commonly found in steel offshore structures. This stress distribution can be characterized by the degree of bending (DoB). Although multi-planar joints are an intrinsic feature of offshore tubular structures and the multi-planarity usually has a considerable effect on the DoB values at the brace-to-chord intersection, few investigations have been reported on the DoB in multi-planar joints due to the complexity of the problem and high cost involved. In the present research, data extracted from the stress analysis of 243 finite element (FE) models, verified based on available parametric equations, was used to study the effects of geometrical parameters on the DoB values in two-planar tubular DYT-joints. Parametric FE study was followed by a set of nonlinear regression analyses to develop six new DoB parametric equations for the fatigue analysis and design of axially loaded two-planar DYT-joints.

• Mycobiology
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• 제51권5호
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• pp.281-287
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• 2023

The symbiotic association between fungus-gardening termites Macrotermes and its fungal symbiont has a moderate degree of specificity-although the symbiotic fungi (Termitomyces) form a monophyletic clade, there is not a one-to-one association between termite species and their fungus-garden associates. Here, we aim to determine the origin and phylogenetic relationships of Termitomyces in Oman. We used sequences of the internal transcribed spacer region (ITS) and the nuclear large subunit ribosomal RNA (LSU rRNA, 25S) gene and analyzed these with sequences of Termitomyces from other geographic areas. We find no evidence for more than a single colonization of Oman by Termitomyces. Unexpectedly, we find Termitomyces in Oman is most closely related to the symbiont of M. subhyalinus in West Africa rather than to those of geographically closer populations in East Africa.

• 한국축산식품학회지
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• 제44권3호
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• pp.499-514
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• 2024

Cultured meat has been gaining popularity as a solution to the increasing problem of food insecurity. Although research on cultured meat started later compared to other alternative meats, the industry is growing rapidly every year, with developed products evaluated as being most similar to conventional meat. Studies on cultured meat production techniques, such as culturing new animal cells and developing medium sera and scaffolds, are being conducted intensively and diversely. However, active in-depth research on the quality characteristics of cultured meat, including studies on the sensory and storage properties that directly influence consumer preferences, is still lacking. Additionally, studies on the combination or ratio of fat cells to muscle cells and on the improvement of microbiota, protein degradation, and fatty acid degradation remain to be conducted. By actively investigating these research topics, we aim to verify the quality and safety of cultured meats, ultimately improving the consumer preference for cultured meat products.

• Fisheries and Aquatic Sciences
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• 제22권12호
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• pp.30.1-30.11
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• 2019

Marine natural products isolated from the sponge Fascaplysinopsis cf reticulata, in French Polynesia, were investigated as an alternative to antibiotics to control pathogens in aquaculture. The overuse of antibiotics in aquaculture is largely considered to be an environmental pollution, because it supports the transfer of antibiotic resistance genes within the aquatic environment. One environmentally friendly alternative to antibiotics is the use of quorum sensing inhibitors (QSIs). Quorum sensing (QS) is a regulatory mechanism in bacteria which control virulence factors through the secretion of autoinducers (AIs), such as acyl-homoserine lactone (AHL) in gram-negative bacteria. Vibrio harveyi QS is controlled through three parallel pathways: HAI-1, AI-2, and CAI-1. Bioassay-guided purification of F. cf reticulata extract was conducted on two bacterial species, i.e., Tenacibaculum maritimum and V. harveyi for antibiotic and QS inhibition bioactivities. Toxicity bioassay of fractions was also evaluated on the freshwater fish Poecilia reticulata and the marine fish Acanthurus triostegus. Cyclohexanic and dichloromethane fractions of F. cf reticulata exhibited QS inhibition on V. harveyi and antibiotic bioactivities on V. harveyi and T. maritimum, respectively. Palauolide (1) and fascaplysin (2) were purified as major molecules from the cyclohexanic and dichloromethane fractions, respectively. Palauolide inhibited QS of V. harveyi through HAI-1 QS pathway at 50 ㎍ ml^-1 (26 μM), while fascaplysin affected the bacterial growth of V. harveyi (50 ㎍ ml^-1) and T. maritimum (0.25 ㎍). The toxicity of fascaplysin-enriched fraction (FEF) was evaluated and exhibited a toxic effect against fish at 50 ㎍ ml^-1. This study demonstrated for the first time the QSI potential of palauolide (1). Future research may assess the toxicity of both the cyclohexanic fraction of the sponge and palauolide (1) on fish, to confirm their potential as alternative to antibiotics in fish farming.

• Korea-Australia Rheology Journal
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• 제21권4호
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• pp.269-280
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• 2009

The drop formation dynamics of a shear thinning, elastic, yield stress ($\tau_o$) fluid (Carbopol 980 (poly(acrylic acid)) dispersions) in silicone oil has been investigated in a flow-focusing microfluidic channel. The rheological character of each solution investigated varied from Netwonian-like through to highly non-Newtonian and was varied by changing the degree of neutralization along the poly (acrylic acid) backbone. We have observed that the drop size of these non-Newtonian fluids (regardless of the degree of neutralisation) showed bimodal behaviour. At first we observed increases in drop size with increasing viscosity ratio (viscosity ratio=viscosity of dispersed phase (DP)/viscosity of continuous phase (CP)) at low flowrates of the continuous phases, and thereafter, decreasing drop sizes as the flow rate of the CP increases past a critical value. Only at the onset of pinching and during the high extensional deformation during pinch-off of a drop are any differences in the non-Newtonian characteristics of these fluids, that is extents of shear thinning, elasticity and yield stress ($\tau_o$), apparent. Changes in these break-off dynamics resulted in the observed differences in the number and size distribution of secondary drops during pinch-off for both fluid classes, Newtonian-like and non-Newtonian fluids. In the case of the Newtonian-like drops, a secondary drop was generated by the onset of necking and breakup at both ends of the filament, akin to end-pinching behavior. This pinch-off behavior was observed to be unaffected by changes in viscosity ratio, over the range explored. Meanwhile, in the case of the non-Newtonian solutions, discrete differences in behaviour were observed, believed to be attributable to each of the non-Newtonian properties of shear thinning, elasticity and yield stress. The presence of a yield stress ($\tau_o$), when coupled with slow flow rates or low viscosities of the CP, reduced the drop size compared to the Newtonian-like Carbopol dispersions of much lower viscosity. The presence of shear thinning resulted in a rapid necking event post onset, a decrease in primary droplet size and, in some cases, an increase in the rate of drop production. The presence of elasticity during the extensional flow imposed by the necking event allowed for the extended maintenance of the filament, as observed previously for dilute solutions of linear polymers during drop break-up.

• Journal of Forest and Environmental Science
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• 제11권1호
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• pp.81-101
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• 1995

지표-형질의 상관은 우량 개체 선발과 유전획득량의 증대를 위해 임목 육종에서 해결되어야 할 중요한 과제 중의 하나로 최근 분자유전학적 수준에서의 임의 증폭 다형 디엔에이 (RAPD) 기술의 발달로 이의 해결이 눈 앞에 다가왔다. 호주 퀸즈랜드산림청과 퀸즈랜드대 임목생물공학연구소가 공동 연구하고 있는 슬래쉬소나무, 카리비아소나무 및 그 교잡종에 있어 이 기술을 이용한 수피 두께에 대한 연구 및 육종 계획 전략을 소개한다. 1대 잡종에서 186개의 지표를 포함한 총 길이 1641cM의 16개 연관군의 유전적 지도가 작성되었고, 이 연관군 지도에 수피 두께를 지배하는 6개의 유전자좌가 추정되었다. 또한, 유전적 지표를 이용한 조기 선발을 위해 먼저 중요 형질을 지배하는 유전자들에 대한 종 특성 유전적 지표를 결정하고, 다음 여러가지 대립유전자형에 대한 지표-대립유전자 상관을 구명하는 2단계 전략이 제시되었다. 소나무류는 발아시 양료로 쓰이는 자성배우체는 모수에서 유래하나, 접합자인 배는 양친수로부터 유래하므로 이러한 이질적 유전 조성을 갖인 종자의 발달을 이용한 RAPD 지표와 형질의 상관 연구는 배 단계에서도 우량 개체의 선발을 가능하게 하여 소나무류 육종의 장래를 밝게 하고 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권10호
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• pp.4429-4434
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• 2015

Background: Public awareness/knowledge on oral and pharyngeal cancer (OPC), potentially malignant disorders (PMODs) and their risk factors is crucial for prevention and early detection of OPC and PMODs. Yet, there are no published data available on the awareness and knowledge of OPC and PMODs among people living in Far North Queensland, Australia. Materials and Methods: This study was conducted as a cross sectional survey. A self-administered questionnaire was designed and consisted of relevant questions to ascertain socio-demographic information, awareness and knowledge of OPC, PMODs and risk factors and questions on participant's exposure to risk factors and dietary history were also included. Survey was carried out at the Dental Clinic of the James Cook University School of Dentistry (JCU Dental), Cairns, Australia. Subjects above the age of 20 years (n=366) were randomly selected during the period from 31st July to 6th September 2013 and questionnaire was distributed to complete while they are waiting for treatment. Data analysis was carried out using SPSS version 21 and the chi -squared test was employed to compare groups. P<0.05 was considered statistically significant. Results: The study revealed that 52.3% of the respondents were aware of the existence of OPC but only 19.0% were aware of PMODs. Of those who were aware of oral cancer, 92% agreed or strongly agreed that smoking is a strong risk factor for OPC. Similarly a relatively high proportion of the respondents agreed or strongly agreed that tobacco chewing (84%), tobacco chewing with areca nut (68%), chewing areca nut alone (51%) and exposure to actinic radiation (71%) as risk factors. However, the results for alcohol intake, age, and HPV infection were found to be relatively poor with proportions 33%, 34%, and 23% respectively. Conclusions: This study revealed an alarming lack of awareness and knowledge of OPC and PMODs.