• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.338-342
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• 1988

Recently, in sequence control systems, high flexibility and maintenance of control software are required. This is because product life cycles become shorter and control specification must be changed frequently. The authors extend the concept of Safe Petri Net to develop the design and analysis tool for sequence control systems taking the safeness and notation of input/output functions into consideration. Extended Safe Petri Net (S-Net) is proposed as such a new graph model and real time scanning algorithm based on S-Net is developed.

• Communications for Statistical Applications and Methods
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• v.20 no.5
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• pp.417-425
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• 2013

We consider an extended version of a logarithmic series distribution and discuss the estimation of its parameters by the method of moments and the method of maximum likelihood. Test procedures are suggested to test the significance of the additional parameter of this distribution and all procedures are illustrated with the help of real life data sets. In addition, a simulation study is conducted to assess the performance of the estimators.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.737-754
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• 2019

Peaches have soft tissues compared to other fruits and are vulnerable to softness, wounds, and loss of marketability due to the weak fruit hardness after harvest. It is necessary to develop a technology to improve the shelf-life of the fruit to expand the distribution of peaches. Calcium compounds and chitosan have an important role in improving the shelf-life of fruit by maintaining the hardness and reducing the respiration rate in peach fruits. In this study, to select useful compounds to improve the shelf-life of peaches, calcium citrate, calcium chloride, calcium nitrate, GH-Ca, OS-Ca, chitosan, and chitosan dissolved in calcium chloride were sprayed onto peach trees. The characteristics of the harvested fruits were investigated after the 'Kumhong' and 'Madoka' peach tree treatments. The hardness of the fruit was kept the highest with the combined treatment and remained high with the calcium citrate, chitosan and calcium nitrate treatments. Ethylene production and respiration were effectively inhibited by the GH-Ca and chitosan treatments. There was no significant difference in soluble solids content and acidity among the fruits treated with the chemicals. The coloration of the fruit skin was not delayed by the calcium and chitosan chemical treatments. Calcium compounds were increased in the fruits and leaves of the peach trees treated with the chemicals compared to the untreated ones. These results suggest that the calcium treatment extended the shelf-life by increasing the calcium content in the leaves and fruits of the peach trees.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.3
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• pp.153-159
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• 2018

Many researches have been carried out on carbonation, a representative deterioration in underground structure. The carbonation of RC (Reinforced Concrete) structure can cause steel corrosion through pH drop in concrete pore water. However extension of service life in RC structures can be obtained through simple surface protection. Unlike the conventional deterministic maintenance technique, probabilistic technique can consider a variation of service life but it deals with only normal distributions. In the work, life time-probability distributions considering not only normal but also log distributions are induced, and repair cost estimation technique is proposed based on the induced model. The proposed technique can evaluate the repair cost through probabilistic manner regardless of normal or log distribution from initial service life and extended service life with repair. When the extended service life through repair has log distribution, repair cost is effectively reduced. The more reasonable maintenance strategy can be set up though actual determination of life-probability distribution based on long term tests and field investigations.

• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.515-520
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• 2007

본 연구의 목적은 농산물 이력추적 시스템을 사용하는 생산자들의 시스템에 대한 만족과 지속적인 사용의도에 영향을 주는 요인을 파악하여 농산물 이력추적 시스템의 활성화를 위한 기초자료를 제공하는 것이다. 실증적인 검증을 위하여 재사용의도와 관련한 선행연구들을 검토하여 TAM과 ECT를 결합시킨 Extended ECT 모델을 제안하고 실제 농산물 이력추적 사업에 시범참여하고 있는 생산자 100명을 상대로 설문조사를 실시하였다. 분석 결과, 지각된 유용성 및 용이성, 수익성은 시스템 만족에 긍정적인 영향을 미치며 이는 지속적인 사용의도로 연결되었으나 지각된 용이성과 유용성이 직접적으로 지속적인 사용의도에 영향을 미치는 것은 아닌 것으로 나타났다. 이 결과는 농산물 외의 식품 이력추적 시스템에도 포괄적으로 적용이 가능하다.

• Journal of Applied Reliability
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• v.5 no.3
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• pp.357-371
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• 2005

Nitrogen oxide gases which were produced by spontaneous reaction of nitrocellulose (NC) in the single base propellant accelerate the decomposition of propellant, and result in the reduction of shelf life, The amount of nitrogen oxide was reduced by the addition of $0.3wt\%$ CaCO3 to conventional stabilizer(DPA) which extended the shelf life of the single base propellant as much as twice compared with commercial propellant.

• Journal of the Korea Society of Computer and Information
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• v.27 no.11
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• pp.89-98
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• 2022

Using the extended technology acceptance model, this study aims to quantitatively analyze the user experience with the . In the case of Perceived Usefulness and Perceived Ease of Use, only limited detailed factors have significant impacts on the degree of satisfaction. The degree of satisfaction has positive correlations with the degree of immersion and the variables of Behavioral Intention to Use Metaverse. Although sophisticatedly remediates using digital technology to provide visitors with the sameness of exhibits, exhibition circulation and interaction method, the metaverse exhibition does not acquire the same value of the exhibition. In conclusion, cannot replace , however, it has the potential to offer learning usefulness to visitors with low accessibility to the art museum.

• Journal of Life Science
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• v.20 no.5
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• pp.676-682
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• 2010

This study focused on typing of the extended-spectrum $\beta$-lactamase (ESBL) produced in organisms isolated from a natural environment, rather than a clinical setting. Samples were collected from drain water issuing from a sewage plant in Kwanganri (Busan, Korea). Following double disk synergy testing, 29 strains were selected as potential ESBL positive strains. Of these, 15 strains were transconjugants of the sodium azide resistant recipient strain Escherichia coli J53 and analyzed biochemically including indole, methyl-red, Voges-Proskauer, Simmon's citrate, decarboxylase-dihydrolase and sugar-fermentation tests. The tests classified the 15 strains as Klebsiella pneumoniae (n=13) and Escherichia coli (n=2). The type of ESBL from each strain was deduced by isoelectric focusing point analysis and DNA sequencing. The results indicated that the types of ESBL were SHV-12 (n=4) and SHV-12/TEM-1 (n=9) from K. pneumoniae and TEM-1 (n=2) from E. coli strains.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.4
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• pp.386-397
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• 2008

Due to the rapid advancement of technologies, a growing number of innovative products with a short life-cycle have been introduced to the market. As the life-cycles of such products are shorter than those of durable goods, the demand variation during the life-cycle adds to the difficulty of inventory management. Traditional inventory planning models and techniques mostly deal with products that have long life-cycles. The assumptions on the demand pattern and subsequent solution approaches are generally, not suitable for dealing with products with short life-cycles. In this research, inventory replenishment problems based on the logistic demand model are formulated and solved to facilitate the management of products with short life-cycles. An extended Wagner- Whitin approach is used to determine the replenishment cycle, schedules and lot-sizes.

• Korean Journal of Organic Agriculture
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• v.3 no.1
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• pp.43-70
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• 1994

Presently the concept of organic farming has not simply technical categories such as no agricul-tural chemicals and no chemical fertilizer but can be also extended to the categories of economics, food nutrition, environmental and philosophical aspects. Accordingly, in order to understand cor-rectly organic farming, it is necessary to look into the concept including these extended aspects. So the production and consumption activities of organic farming products are largely based on the fundamental philosophy of organic farming. That is, all the life that is included in an ecosystem has to live in symbiosis, which is based on life circulation principle. And if this circultaion system is destroyed, human life may be threatended. Farmers who produce organic farming prducts(organic farmer) receive price higher than general farmers. This study shows the gap of 46.9% in two products. Also, since the price of organic farming products is fluctuated less relatively, Organic farming pruducts can be competed against imported agricultural products in terms of food safety. And organic farming should be managed by crop rotation and composite farm management upon which the principle of material circulation is worked. This composite management is devided into 2 classes, which are individually livestock-have-composite management and regional composite management. These management method means that organic materials are crucial to maintain the structure and fertility and these organic materials are easily obtained from animal as by-products.