This study aims to establish a modified analytical method with sensitivity and reliability for streptomycin (STP) and dihydrostreptomycin (DHS) of residues level in pig tissues, plasma and urine by LC-MS/MS on the basis of previous studies. The mass parameters of quantitative and qualitative ions for STP and DHS were optimized using multiple reaction monitoring in positive mode. The separation of compounds was conducted using BEH Amide column according to material’s characteristics. The analytes in plasma were extracted with only organic solvents. In muscle and kidney, KH2PO4 buffer solution containing 2% CCl3COOH and EDTA-Na was used as extraction solvent. The WCX cartridege was selected as SPE cartridge in considering high recoveries for STP and DHS. The analytes in urine were extracted by organic solvents with acid and addition of EDTA. The limits of detection (LODs) in STP and DHS ranged 0.45~3.66 μg/kg and 0.22~0.78 μg/kg, respectively. The limits of quantification (LOQs) were 1.35~11.10 μg/kg in STP and 0.66~2.36 μg/kg in DHS. The recoveries (%) were 94.29~104.5% in STP and 92.32~108.45% in DHS except for plasma with lower values (61.45/68.5%, respectively). In the precision evaluation, the coefficient of variation (CV, %) of STP showed <10.50% on intra-day and <18.04% on inter-day. The CV (%) of DHS showed <8.42% on intra-day, whereas <17.98% on inter-day. The modified method is reliable for continuous residual monitoring in pig to ensure food safety for consumer’s health. In addition, this method could be used in study relation to residue depletion and pharmacokinetics of veterinary drug.

This study aimed to identify sub-dimensions of the authenticity and fictionality of a brand story and analyze the effects of authenticity and fictionality on customer-based brand equity. Data were obtained from a group of 213 males and females in their 20s and 30s living in Korea using an online survey institute. Results showed that the authenticity and fictionality of a brand story are composed of reality, excitement, exaggeration, fictional symbolism, influence, sincerity, relativeness, mysteriousness, and unreality. Of these, sincerity, excitement, reality, influence, and mysteriousness had significant effects on brand imagery; sincerity particularly exerted a relatively more substantial influence on brand imagery. Also, influence, mysteriousness, excitement, and relativeness impacted performance positively, and exaggeration impacted performance negatively. This indicated that a well-constructed brand story with authenticity and fictionality had a positive impact on the brand image. Excitement, mysteriousness, reality, relativeness, sincerity, and influence of a brand story had significant effects on brand judgement. In contrast, only excitement and influence positively impacted brand feelings, and unreality had a negative impact on feelings. The exciting and influential brand story impacted brand attitude. Also, brand image and attitude positively impacted sharing and purchase intention, while brand performance did not affect recommendation intention. These findings contribute to identifying a brand story’s attributes, authenticity, and fictionality and provide insights for marketers on creating brand stories to increase brand image and attitude and to build customer-based brand equity.

Canine parvovirus type-2 (CPV-2) is a major etiological agent causing gastrointestinal enteritis in domestic and wild carnivores. Since the emergence of CPV-2 in the late 1970s, subtypes CPV-2a, CPV-2b, and CPV-2c have spread worldwide. CPV-2 prevalence differed according to region and season. This study aims to investigate the prevalence of CPV-2 infection in Korea. Samples were collected from 536 dog feces in animal shelters and 225 necropsied intestinal tissues of dog carcasses submitted in the Animal and Plant Quarantine Agency (APQA) for diagnostic purposes from 2016 to 2020 in Korea. Among the 761 samples, 181 (23.8%) were positive for the following subtypes: CPV-2a (n=138), CPV-2c (n=16), CPV-2b (n=14), and CPV-2 (n=2). Feline parvovirus (n=2) and co-infection with CPV-2a and CPV-2c (n=1) were also detected. There was no significant difference in the regional distribution of CPV-2 in Korea, which is prevalent in winter. This result shows the prevalence of CPV-2 according to various environments in Korea and will be useful in establishing an effective prevention strategy against CPV-2 that reflects the situation in Korea with continuous monitoring.

Electrochemical water splitting is an important process for next generation of eco-friendly energy systems. The oxygen evolution reaction (OER), which occurs at an anode during the process, requires efficient electrocatalysts to reduce activation energies. Although Ru- or Ir-containing materials show excellent electrocatalytic activities, their high cost is a critical drawback. Consequently, the development of efficient electrocatalysts composed of low-cost metal components is a great challenge. In this study, we develop a new route to produce a hybrid material (Fe–NC) containing Fe3C particles dispersed on the surface of N-doped carbon (NC) materials by heat treatment of a mixture of urea and Fe(II)Cl2(H2O)4. Microscopic analyses prove that the Fe3C particles are placed on the surfaces of thin NC materials. Additionally, various characterizations reveal that the particles contain Fe3C structure. Fe–NC shows good electrocatalytic properties with onset and overpotentials of 1.57 V and 545 mV, respectively, for OER in KOH electrolyte. This study suggests the possibility of the use of Fe3C- based composites as OER electrocatalysts.

Through constructing statistical fracture network model based on discrete element method, the evolution characteristics of the fracture aperture had been directly simulated and evaluated caused by redistributed stress after the borehole excavation. This study focuses on the size effect of the discrete element method for the analysis of the effective distance of fracture aperture change after the borehole excavation. A two-dimensional trace-type domain with a maximum size of 1.1 m2 was created using a discrete fracture network with stochastic information of KURT. A total of eight domains with different sizes were constructed from the largest domain area to the 0.4 m2 analysis area. The aperture change ratio which can be depending on the domain size was examined. The ratio was investigated by comparing the aperture size before and after the simulation of borehole excavation. In addition, the effective range of aperture changes was analyzed by comparing the re-distribution distance from the center of the borehole. Based on dimensional analysis, input variables (borehole radius, occurrence distance of aperture changes, domain size) were modeled using exponential distribution form. Through the analysis model, two dimensionless variables were derived to investigate the expected distance of the aperture changes and appropriate DFN domain size for simulating bole excavation. As an application example of the 3-inch borehole simulation, the analysis model predicted that the range of aperture changes could occur within a radius of about 0.98 m from the borehole center, and the suitable size of the model had been inferred as about 5 × 5 m for minimizing the domain size effect.

This study deals with replacement analysis of deteriorated equipment for improving productivity of production system. Frequent breakdown of the deteriorated equipment causes a situation that reduces productivity such as low product quality, process delay, and repair cost. However, the replacement of new equipment will be required a high initial investment cost, so it is important to analysis the economic feasibility. Therefore, we analyze the effect of the production system due to the aging effect of the equipment and the feasibility of equipment replacement based on the economic analysis. The process flow, working time, logistics movement, etc. are analyzed in order to build the simulation modeling for a ship and land switchboard production system. Using numerical examples, the economic feasibility analysis of equipment replacement through replacement of existing deteriorated equipment and additional arrangement of new facilities is performed.

본 연구는 제도적 이중성(institutional duality)의 관점에서 해외 자회사 자율성의 선행 요인 과 그 성과에 대해 연구하였다. 해외 자회사의 자율성은 자회사가 본사의 영향을 받지 않고 전략적 의사결정을 하고 그 성과에 책임을 질 수 있는 역할을 의미한다. 경영상 본사에서 파생되었으나 물 리적으로 해외에 자리하는 해외 자회사의 자율성에 상반된 영향을 주는 본국과 현지국의 제도적 요 소는 본사의 국제화전략 지향성과 지역 이해관계자 요구이다. 해외 자회사가 직면하게 되는 이러한 상반된 제도적 환경의 자율성에의 효과를 살펴보기 위해, 19개 국가에 진출한 177개 한국기업 해 외 자회사를 대상으로 GLS 분석을 실시하였다. 본사의 국제화전략이 범세계적 통합보다 현지국에 서의 지역별 대응을 지향할수록, 또 지역 이해관계자들의 요구가 강할수록 해외 자회사의 자율성이 높아지는 것으로 분석결과는 나타났다. 해외 자회사들의 자율성이 높을수록 자회사는 해당 지역 이 해관계자 들과의 긴밀한 관계를 통해 필요한 자원을 획득하고 본사로부터 제공된 자원과의 적절한 융합을 통해 자회사만의 독특한 경쟁우위를 창출하며 이것이 종국에 기업 성과를 상승시키는 것으 로 분석결과는 보여주고 있다. 또한, 본사의 국제화전략이 현지국에서의 지역별 대응을 지향할수록 자회사 자율성이 자회사 성과에 미치는 긍정적인 영향력을 강화하는 조절 효과가 있는 것으로 나타 나고 있다. 더 나아가, 자회사 자율성은 지역 이해관계자들의 요구가 자회사 성과로 이어지는 데에 부분 매개의 역할을 하는 것으로 확인되었다. 이러한 결과는 다국적 기업의 본사는 해외 자회사의 운영에 있어 지역별 유연성을 발휘할 필요가 있고, 해외 자회사 또한 본사와 현지국 양 편에서 오 는 제도적 압력의 균형점을 찾기 위해 노력할 필요가 있음을 시사한다.

In the era of the 4th industrial revolution driven by the convergence of ICT(information and communication technology) and manufacturing, research on smart factories is being actively conducted. In particular, the manufacturing industry prefers smart factories that autonomously connect and analyze data. For the efficient implementation of smart factories, it is essential to have an integrated production system that vertically integrates separately operated production equipment and heterogeneous S/W systems such as ERP, MES. In addition, it is necessary to double-verify production data by using automatic data collection technology so that the production process can be traced transparently. In this study, we want to show a case of data-centered integration of a large aircraft parts processing factory that requires high precision, takes a long time, and has the characteristics of processing large raw materials. For this, the components of the data-oriented integrated production system were identified and the connection structure between them was explained. And we would like to share the experience gained through the design and implementation case. The integrated production system proposed in this study integrates internal components based on data, which is expected to serve as a basis for SMEs to develop into an advanced stage, and traces materials with RFID technology.

Oligosaccharide-producing lactic acid bacteria were isolated from young radish and identified as Weissella cibaria YRK005. Oligosaccharides from W. cibaria YRK005 were purified using size-exclusion high-performance liquid chromatography, and their structure was determined. The oligosaccharides consisted of glucose only, 1 H-nuclear magnetic resonance analysis revealed that the oligosaccharides consisted of 93.8% α-1,6 glycosidic linkages and 6.2% α-1,4 glycosidic linkages, and molecular weight was determined to be 1.1210 2 Da. When the oligosaccharides' prebiotic effect on probiotic strains was examined, the oligosaccharides promoted the growth of four probiotic strains, Bifidobacterium adolescentis, Lactobacillus acidophilus, Lactococcus lactis, and Lactobacillus pentosus, compared to fructo-oligosaccharides as a reference. These results indicated that oligosaccharides from W. cibaria YRK005 could be used as potential prebiotics.