• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.4
• /
• pp.194-202
• /
• 2019

Reliability analysis of the components frequently starts with the data that manufacturer provides. If enough failure data are collected from the field operations, the reliability should be recomputed and updated on the basis of the field failure data. However, when the failure time record for a component contains only a few observations, all statistical methodologies are limited. In this case, where the failure records for multiple number of identical components are available, a valid alternative is combining all the data from each component into one data set with enough sample size and utilizing the useful information in the censored data. The ROK Navy has been operating multiple Patrol Killer Guided missiles (PKGs) for several years. The Korea Multi-Function Control Console (KMFCC) is one of key components in PKG combat system. The maintenance record for the KMFCC contains less than ten failure observations and a censored datum. This paper proposes a Bayesian approach with a Dirichlet mixture model to estimate failure time density for KMFCC. Trends test for each component record indicated that null hypothesis, that failure occurrence is renewal process, is not rejected. Since the KMFCCs have been functioning under different operating environment, the failure time distribution may be a composition of a number of unknown distributions, i.e. a mixture distribution, rather than a single distribution. The Dirichlet mixture model was coded as probabilistic programming in Python using PyMC3. Then Markov Chain Monte Carlo (MCMC) sampling technique employed in PyMC3 probabilistically estimated the parameters' posterior distribution through the Dirichlet mixture model. The simulation results revealed that the mixture models provide superior fits to the combined data set over single models.

• Korean Journal of Medicinal Crop Science
• /
• v.2 no.2
• /
• pp.162-167
• /
• 1994

This study was carried out to investigate the compositions of fatty acids, inorganic components and volatile organic acids from Korean valerian roots, Valeriana fauriei var. dasycarpa Hara and Valeriana officinalis var. latifolia Miq. The contents of total lipids ranged from 3.7 % to 4.5% and the major fatty acids were linoleic, linolenic and palmitic acid. Ash contents ranged from 4.3% to 6.3%. and the contents of Na, Fe, Zn and Cu showed some quantitative differences depending upon grown region or species. Fourty components were identified from acidic fraction of dichloromethane extract of V. fauriei var. dasycarpa Hara, of which the major components were 3-methyl butanoic, dimethoxy-2-propenoic. 3, 4-dimethoxy benzoic and 3-methyl pentanoic acid.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.9
• /
• pp.1407-1414
• /
• 2018

Objective: The aim of this study was to estimate (co) variance components and genetic parameters for categorical carcass traits using Bayesian inference via mixed linear and threshold animal models in Anglonubian goats. Methods: Data were obtained from Anglonubian goats reared in the Brazilian Mid-North region. The traits in study were body condition score, marbling in the rib eye, ribeye area, fat thickness of the sternum, hip height, leg perimeter, and body weight. The numerator relationship matrix contained information from 793 animals. The single- and two-trait analyses were performed to estimate (co) variance components and genetic parameters via linear and threshold animal models. For estimation of genetic parameters, chains with 2 and 4 million cycles were tested. An 1,000,000-cycle initial burn-in was considered with values taken every 250 cycles, in a total of 4,000 samples. Convergence was monitored by Geweke criteria and Monte Carlo error chain. Results: Threshold model best fits categorical data since it is more efficient to detect genetic variability. In two-trait analysis the contribution of the increase in information and the correlations between traits contributed to increase the estimated values for (co) variance components and heritability, in comparison to single-trait analysis. Heritability estimates for the study traits were from low to moderate magnitude. Conclusion: Direct selection of the continuous distribution of traits such as thickness sternal fat and hip height allows obtaining the indirect selection for marbling of ribeye.

• Korean Journal of Food Science and Technology
• /
• v.40 no.3
• /
• pp.271-276
• /
• 2008

In this study, volatile compounds were isolated from traditional and commercial fermented soybean pastes according to different heating temperatures (room temperature, $50^{\circ}C$, $100^{\circ}C$) using headspace-solid phase microextraction (HS-SPME). The compounds were then analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 51 volatile components, including 18 esters, 3 alcohols, 6 acids, 8 pyrazines, 5 volatile phenols, 6 aldehydes, and 5 miscellaneous compounds, were identified. Esters and acids such as ethyl hexadecanoate, acetic acid, and 2/3-methyl butanoic acid were the largest groups among the quantified volatiles. By applying principal component analyses to the GCMS data sets, differences were observed in the volatile components of the soybean pastes as to the different heating temperatures. A large variation was shown between the volatile components of the traditional and commercial soybean pastes by increasing the heating temperature. Commercial samples had significantly higher levels of longer chain ethyl esters, aldehydes, and thermal degradation products such as maltol and 2-acetyl pyrrole, while traditional samples showed higher concentrations of acids and pyrazines.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.40 no.3
• /
• pp.138-147
• /
• 2017

As the functions and structure of the system are complicated and elaborated, various types of structures are emerging to increase reliability in order to cope with a system requiring higher reliability. Among these, standby systems with standby components for each major component are mainly used in aircraft or power plants requiring high reliability. In this study, we consider a standby system with a multi-functional standby component in which one standby component simultaneously performs the functions of several major components. The structure of a parallel system with multifunctional standby components can also be seen in real aircraft hydraulic pump systems and is very efficient in terms of weight, space, and cost as compared to a basic standby system. All components of the system have complete operation, complete failure, only two states, and the system has multiple states depending on the state of the component. At this time, the multi-functional standby component is assumed to be in a non-operating standby state (Cold Standby) when the main component fails. In addition, the failure rate of each part follows the Weibull distribution which can be expressed as increasing type, constant type, and decreasing type according to the shape parameter. If the Weibull distribution is used, it can be applied to various environments in a realistic manner compared to the exponential distribution that can be reflected only when the failure rate is constant. In this paper, Markov chain analysis method is applied to evaluate the reliability of multi-functional multi-state standby system. In order to verify the validity of the reliability, a graph was generated by applying arbitrary shape parameters and scale parameter values through Excel. In order to analyze the effect of multi-functional multi-state standby system using Weibull distribution, we compared the reliability based on the most basic parallel system and the standby system.

• Journal of Ginseng Research
• /
• v.46 no.1
• /
• pp.104-114
• /
• 2022

Background: Abnormalities of myelin, which increases the efficiency of action potential conduction, are found in neurological disorders. Korean Red Ginseng (KRG) demonstrates therapeutic efficacy against some of these conditions, however effects on oligodendrocyte (OL)s are not well known. Here, we examined the effects of KRG-derived components on development and protection of OL-lineage cells. Methods: Primary OL precursor cell (OPC) cultures were prepared from neonatal mouse cortex. The protective efficacies of the KRG components were examined against inhibitors of mitochondrial respiratory chain activity. For in vivo function of Rb1 on myelination, after 10 days of oral gavage into adult male mice, forebrains were collected. OPC proliferation were assessed by BrdU incorporation, and differentiation and myelination were examined by qPCR, western blot and immunocytochemistry. Results: The non-saponin promoted OPC proliferation, while the saponin promoted differentiation. Both processes were mediated by AKT and extracellular regulated kinase (ERK) signaling. KRG extract, the saponin and non-saponin protected OPCs against oxidative stress, and both KRG extract and the saponin significantly increased the expression of the antioxidant enzyme. Among 11 major ginsenosides tested, Rb1 significantly increased OL membrane size in vitro. Moreover, Rb1 significantly increased myelin formation in adult mouse brain. Conclusion: All KRG components prevented OPC deaths under oxidative stress. While non-saponin promoted proliferation, saponin fraction increased differentiation and OL membrane size. Furthermore, among all the tested ginsenosides, Rb1 showed the biggest increase in the membrane size and significantly enhanced myelination in vivo. These results imply therapeutic potentials of KRG and Rb1 for myelin-related disorders.

• Macromolecular Research
• /
• v.17 no.12
• /
• pp.976-986
• /
• 2009

With the study goal of firstly elucidating the anisotropic interactions between oriented polymer chain segments and liquid crystal (LC) molecules, and secondly of determining the contributions of the chemical components of the polymer segments to the film surface topography, LC alignment, pretilt, and anchoring energy, we synthesized three dianhydrides, 1,4-bis(4'-t-butylphenyl)pyromellitic dianhydride (BBPD), 1,4-bis(4'-trimethylsilylphenyl)pyromellitic dianhydride(BTPD), and 2,2'-bis(4"-tert-butylphenyl)-4,4',5,5'-biphenyltetracarboxylic dianhydride (BBBPAn), and a series of their organosoluble polyirnides, BBPD-ODA, BBPD-MDA, BBPD-FDA, BTPD-FDA, and BBBPAn-FDA, which contain the diamines 4,4'-oxydianiline (ODA), 4,4'-methylenediamine (MDA), and 4,4'-(hexafluoroisopropylidene)dianiline (FDA). All the polyimides were determined to be positive birefringent polymers, regardless of the chemical components. Although all the rubbed polyimide films exhibited microgrooves which were created by rubbing process, the film surface topography varied depending on the polyimides. In all the rubbed films, the polymer chains were unidirectionally oriented along the rubbing direction. However, the degree of in-plane birefringence in the rubbed film varied depending on the polyimides. The rubbing-aligned polymer chains in the polyimide films effectively induced the alignment of nematic LCs along their orientation directors by anisotropic interactions between the preferentially oriented polymer chain segments and the LCs. The azimuthal and polar anchoring energies of the LCs ranged from $0.45{\times}10^{-4}\;-\;1.37{\times}10^{-4}\;J/m^2$ and from $0.86{\times}10^{-5}\;-\;4.26{\times}10^{-5}\;J/m^2$, respectively, depending on the polyimides. The pretilt angles of the LCs were in the range $0.10-0.62^{\circ}$. In summary, the soluble aromatic polyimides reported here are promising LC alignment layer candidates for the production of advanced LC display devices.

• Nutrition Research and Practice
• /
• v.4 no.2
• /
• pp.106-113
• /
• 2010

In this study, we compared corn gluten hydrolyzates, BCAAs, and leucine for their effects on body weight reduction in high fat-induced obese rats in order to determine the major active components in the corn gluten hydrolyzates. After obesity was induced for 13 weeks with high fat diet, the overweight-induced SD rats (n = 64) were stratified according to body weight, randomly blocked into eight treatments, and raised for 8 weeks. Four groups were changed to a normal diet and the other groups remained on the high fat diet. Each of the groups within both diets was fed either casein, corn gluten hydrolyzates, leucine, or branched chain amino acids, respectively. Daily food intake, body weight gain, and food efficiency ratio were significantly lower in the corn gluten hydrolyzate groups compared to the other groups, regardless of the high fat diet or normal fat diet. The rats fed the corn gluten hydrolyzates diet had the lowest perirenal fat pad weights whereas muscle weight was significantly increased in the corn gluten hydrolyzates groups. Plasma triglyceride, hepatic total lipid, and total cholesterol contents were significantly reduced in the corn gluten hydrolyzates groups. Other lipid profile measurements were not significantly changed. Plasma triglyceride and hepatic total lipid were also significantly reduced in the BCAA and leucine groups. Leptin levels were significantly lower and adiponectin was significantly higher in the corn gluten hydrolyzates groups. Fasting blood glucose, insulin, C-peptide, and HOMA-IR levels were also significantly reduced in the corn gluten hydrozylates groups, regardless of fat level.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.15 no.6
• /
• pp.709-713
• /
• 2005

A new algorithm is proposed for the extraction of line segments to construct 3D wire-frame models of building from the high-resolution aerial images. The purpose of this study Is the accurate and effective extraction of line segments, considering the problems such as discordance of lines and blurred edges existing in the conventional methods. Using the edge map extracted from aerial images, chain code tracking of edges was performed. Then, we extract the line segments considering the strength of edges and the direction of them. SUSAN (Smallest Uni-value Segment Assimilating Nucleus) algorithm proposed by Smith was used to extract an edge map. The proposed algorithm consists of 4 steps: removal of the horizontal, vertical and diagonal components of edges to reduce non-candidate point of line segments based on the chain code tracking of the edge map, removal of contiguous points, removal of the same angle points, and the extraction of the start and end points to be line segments. By comparing the proposed algorithm with Boldt algorithm, better results were obtained regarding the extraction of the representative line segments of buildings, having relatively less extraction of unnecessary line segments.

• KSBB Journal
• /
• v.13 no.1
• /
• pp.90-95
• /
• 1998

Experiments on the process development for the concentration of polyunsaturated fatty acid (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil by using acyl chain specificity of Candida cylindracea lipase were performed. Five kinds of oils were hydrolyzed with Candida cylindracea lipase. Among then, Candida cylindracea lipase just had low activity on the PUFAs-rich fish oil. After the hydrolysis of fish oil, free fatty acid was removed and fatty acid components of glyceride mixtures were analyzed. When the hydrolysis was about 70%, the DHA content in the glyceride mixture was about three times more than that in the original fish oil. The EPA and stearidonic acid contents in the glyceride mixtures, however, were similar to that of the original fish oil. In this work, these results showed that the concentration process of PUFAs by using the acyl chain specificity of Candida cylindreacea lipase was effective in producing glycerides that contained a high concentration of PUFAs in good yield.