• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.145-145
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• 2021

Water distribution networks (WDNs) are designed to satisfy water requirement of an urban community. One of the central issues in human history is providing sufficient quality and quantity of water through WDNs. A WDN consists of a great number of pipelines with different ages, lengths, materials, and sizes in varying degrees of deterioration. The available annual budget for rehabilitation of these infrastructures only covers part of the network; thus it is important to manage the limited budget in the most cost-effective manner. In this study, a novel pipe replacement scheduling approach is proposed in order to smooth the annual investment time series based on a life cycle cost assessment. The proposed approach is applied to a real WDN currently operating in South Korea. The proposed scheduling plan considers both the annual budget limitation and the optimum investment on pipes' useful life. A non-dominated sorting genetic algorithm is used to solve a multi-objective optimization problem. Three decision-making objectives, including the minimum imposed LCC of the network, the minimum standard deviation of annual cost, and the minimum average age of the network, are considered to find optimal pipe replacement planning over long-term time period. The results indicate that the proposed scheduling structure provides efficient and cost-effective rehabilitation management of water network with consistent annual budget.

• BMB Reports
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• v.39 no.4
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• pp.406-411
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• 2006

Signaling lymphocyte activation molecule (SLAM; also known as CD150) is a newly identified cellular receptor for measles virus (MV). The interaction between MV Haemagglutin (MVH) and SLAM is an initial step for MV entry. We have identified several novel SLAM binding sites at residues S429, T436 and H437 of MVH protein and MVH mutants in these residues dramatically decrease the ability to interaction with the cell surface SLAM and fail to co-precipitation with SLAM in vivo as well as malfunction in syncytium formation. At the same time, K58, S59 and H61 of SLAM was also identified to be critical for MVH and SLAM binding. Further, these residues may be useful targets for the development of measles therapy.

• Journal of Power Electronics
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• v.17 no.5
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• pp.1288-1297
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• 2017

The estimation of the remaining useful life (RUL) of lithium-ion (Li-ion) batteries is important for intelligent battery management system (BMS). Data mining technology is becoming increasingly mature, and the RUL estimation of Li-ion batteries based on data-driven prognostics is more accurate with the arrival of the era of big data. However, the support vector machine (SVM), which is applied to predict the RUL of Li-ion batteries, uses the traditional single-radial basis kernel function. This type of classifier has weak generalization ability, and it easily shows the problem of data migration, which results in inaccurate prediction of the RUL of Li-ion batteries. In this study, a novel multi-kernel SVM (MSVM) based on polynomial kernel and radial basis kernel function is proposed. Moreover, the particle swarm optimization algorithm is used to search the kernel parameters, penalty factor, and weight coefficient of the MSVM model. Finally, this paper utilizes the NASA battery dataset to form the observed data sequence for regression prediction. Results show that the improved algorithm not only has better prediction accuracy and stronger generalization ability but also decreases training time and computational complexity.

• The Korean Journal of Applied Statistics
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• v.26 no.3
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• pp.531-547
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• 2013

Multiple life models are useful in multiple life insurance and multiple life annuities when the payment times of benets in these insurance products are contingent on the future life times of at least two people. A reverse mortgage is an annuity whose monthly payments terminate at the death time of the last survivor; however, actuaries have used female life table to calculate monthly payments of a reverse mortgage. This approach may overestimate monthly payments. This paper suggests a last-survivor life table rather than a female life table to avoid the overestimation of monthly payments. Next, this paper derives the distribution of the future life time of last survivor, and calculates the expected life times of male, female and last survivor. This paper calculates principal limits and monthly payments in cases of male life table, female life table and last-survivor life table, respectively. Some numerical examples are discussed.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1408-1410
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• 1997

Arrhenius plots are useful in predicting long-term use temperatures of organic materials and in choosing parameters for accelerated aging. The effects of antioxidant on the heat resistance and temperature index of EPDM rubber used for electrical insulation were investigated. The short-time points were obtained by 50% retention of elongation at break.

• Journal of Life Science
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• v.14 no.3
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• pp.441-444
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• 2004

This study was performed to establish a simple and rapid method for measuring thrombin activity based on weight of fibrin clot formed. The new method was based on the weight measurement of fibrin clot after enzymatic reaction of thrombin with fibrinogen. The fibrin formation depended upon the activities of thrombin used, temperature, incubation time, and centrifugation time. The fibrin formation was increased proportionally up to 1.0 unit/ml of thrombin activity, 4.0mg/ml of fibrinogen concentration, and 5 min of incubation time at 37$^{\circ}C$. The fibrin clot formed was stable by centrifugation at 3,000$\times$g for 5min. This simple assay based on weight of fibrin after centrifugation would be useful for identifying natural food anticoagulants by inhibiting thrombin.

• Journal of Life Science
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• v.16 no.1
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• pp.156-161
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• 2006

The essential oil of Nardostachys jatamansi (Valerianaceae), which has been used for a long time in aroma therapy, was investigated after inhalation or oral administration for its analgesic effect, anticonvulsant action, hypnotic effect and in vitro inhibitory activity on monoamine oxidase. This fragrance oil showed a significant analgesic effect in the phenylquinone-induced .writhing test, suppressed the convulsion induced by pentylenetetrazole and lengthened the pentobarbital-induced sleeping time in a time-dependent manner after fragrance inhalation or dose-independently by oral administration. Its inhibitory activity on monoamine oxidase was remarkable, showing $49.4\%$ inhibition at a concentration of 5.0 mg/ml. Six new terpenes with seven known compounds were detected by our GC-MS analytical conditions used. As a result, the essential oil fragrance of Nardostachys jatamansi would be clinically useful for a sedative by either inhalation or oral administration.

• Korean Journal of Human Ecology
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• v.22 no.2
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• pp.375-389
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• 2013

This survey was conducted to compare the housewife's food habit and food purchase behavior on healthy dietary life. The questionnaires were collected from 151 working housewives and 159 housewives in Daejeon. The average meal time was 20~30 min., 67.6% of respondents ate breakfast and bap with guk(72.9%) was the most favourite foods. Almost half of them ate egg, fruit, vegetable everyday. They concerned highly about less intake of frozen foods(64.2%) and food additives(61.6%) for wellbeing dietary life. Because of close distance and various foods items, big discount store was chosen as food purchase place. The most considering purchase factor was food additives in working housewife and nutrition in housewife(p<0.05). In grocery shopping, working housewife considered children and their husbands(p<0.05). The most important purchase factor was the freshness in vegetables fishes fruits seaweeds eggs. TV or Radio was utilized the most frequently to obtain the useful knowledge on healthy foods. It is suggested that practical information should be offered housewives to purchase proper foods within their income and to manage dietary life according to their family's health condition.

• Journal of the Korean housing association
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• v.12 no.2
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• pp.181-190
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• 2001

The purpose of this study is to analysis web sites which relate to housing environment on Internet and to suggest guidelines which are needed in digital life. Data are in 53 web sites searched by housing environmental word such as people, living, town and so on. The web sites are analyzed by key words. The results of this study were as follow: The web sites are divided into e-housing community, e-housing management, e-housing workplace and e-housing design. These are the digital life of new type. E-housing community sitess key words are 3D virtual world, chatting, information, service, community etc. E-housing community is related to making new wired community cross time and space. E-housing management sitess key words are guard management, apartment management, building management etc. E-housing management sites provide the useful information of housing management. E-housing workplace sitess key words are virtual office. conference etc. E-housing workplace sites enable us to work in cyberspace. E-housing design sitess key words are design, interior, furniture etc. E-housing design sites provide marketing, consulting and designing in relation to the house. The web life style on cyberspace is common and makes many changes happen in house life and environment.

• Mycobiology
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• v.45 no.3
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• pp.204-208
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• 2017

Nosema ceranae is an obligate intracellular fungal parasite that causes mortality in honey bees and enhances the susceptibility of honey bees to other pathogens. Efficient purification of Nosema spores from the midgut of infected honey bees is very important because Nosema is non-culturable and only seasonably available. To achieve a higher yield of spores from honey bees, in this study, we considered that the initial release of spores from the midgut tissues was the most critical step. The use of 2 mm beads along with enzymatic treatment with collagenase and trypsin enhanced the homogenization of tissues and the yield of released spores by approximately 2.95 times compared with the use of common 3 mm beads alone. The optimal time for the enzyme treatment was determined to be 1 hr as measured by the yield and viability of the spores. A one-step filtration using a filter paper with an $8-11{\mu}m$ pore size was sufficient for removing cell debris. This method may be useful to purify not only N. ceranae spores but also other Nosema spp. spores.