• Asian-Australasian Journal of Animal Sciences
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• v.30 no.11
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• pp.1643-1650
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• 2017

Objective: The control of psychrotrophic bacteria causing milk spoilage and illness due to toxic compounds is an important issue in the dairy industry. In South Korea, Gangwon-do province is one of the coldest terrains in which eighty percent of the area is mountainous regions, and mainly plays an important role in the agriculture and dairy industries. The purposes of this study were to analyze the indigenous microbiota of raw milk in Gangwon-do and accurately investigate a putative microbial group causing deterioration in milk quality. Methods: We collected raw milk from the bulk tank of 18 dairy farms in the Hoengseong and Pyeongchang regions of Gangwon-do. Milk components were analyzed and the number of viable bacteria was confirmed. The V3 and V4 regions of 16S rRNA gene were amplified and sequenced on an Illumina Miseq platform. Sequences were then assigned to operational taxonomic units, followed by the selection of representative sequences using the QIIME software package. Results: The milk samples from Pyeongchang were higher in fat, protein, lactose, total solid, and solid non-fat, and bacterial cell counts were observed only for the Hoengseong samples. The phylum Proteobacteria was detected most frequently in both the Hoengseong and Pyeongchang samples, followed by the phyla Firmicutes and Actinobacteria. Notably, Corynebacterium, Pediococcus, Macrococcus, and Acinetobacter were significantly different from two regions. Conclusion: Although the predominant phylum in raw milk is same, the abundances of major genera in milk samples were different between Hoengseong and Pyeongchang. We assumed that these differences are caused by regional dissimilar farming environments such as soil, forage, and dairy farming equipment so that the quality of milk raw milk from Pyeongchang is higher than that of Hoengseong. These results could provide the crucial information for identifying the microbiota in raw milk of South Korea.

• Korean Journal of Animal Reproduction
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• v.3 no.1
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• pp.30-35
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• 1979

A, B and C dilutors were used to make Ka (A plus B (1 : 1)) and Na (B plus C(1 : 1)) dilutors in this experiment. Three aliqots of semen were respectivly diluted 1 : 1 and 1 : 2 (semen: dilutor) with Ka, Na and C dilutors and stored at 5$^{\circ}C$ for 7 days in order to study their livability during storage. Fertility was checked for the diluted semen with Ka, Na and C dilutors. Whole semen and extended semen with Na dilutos with and without DMSO were cold shocked at various temperatures for 10 min. Effects of different 1st and 2nd dilution with A, B, C and Na dilutors and of vessels on freezability of spermatozoa were investigtigated. 1. Extended semen 1 : 2 with Na and C dilutors showed highest live sperm index during storage for 7 days at 5$^{\circ}C$. 2. The components of Na dilutor per 100$m\ell$ were skim milk 2.5g, trisaminomethane 0.54g, citric acid 0.265g, glucose 2.835g, fructose 1.5g, sodium lauryl sulfate, 0.08g, penicillin 0.06g, streptomycin 0.075g, and egg yolk 10$m\ell$. 3. Fertility of diluted semen was higher than that of whole semen. Ka dilutor showed higher fertility than Na and C dilutors, and there was no difference in the fertility between Na and C dilutors. 4. Na dilutor with DMSO showed slightly higher livability than Na dilutor without DMSO during storage for 7 days at 5$^{\circ}C$. 5. Cold shock at 1$0^{\circ}C$ for 10 min. decreased greatly the sperm livalility of whole semen but not of extended semen with Na dilutor. Addition of DMSO to Na dilutor has no effect in prevention of cold shock. 6. The extended semen with C. C dilutor (1st and 2nd dilution with C and C dilutor) showed higher post-thawing sperm livability than A.A and Na. B dilutors. Na. B dilution shwed higher post-thawing sperm livability than A.A dilution. There was no difference in the post-thawing livability between semen in 1$m\ell$ straw and 10$m\ell$ aluminium package.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.5
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• pp.322-330
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• 2020

Modeling for outliers in time series was carried out using the MSL and extreme high, low tide levels (EHL, HLL) data set in the Busan and Mokpo stations. The time-series model is seasonal ARIMA model including the components of the AO (additive outliers) and LS (level shift). The optimal model was selected based on the AIC value and the model parameters were estimated using the 'tso' function (in 'tsoutliers' package of R). The main results by the model application, i.e.. outliers and level shift detections, are as follows. (1) The two AO are detected in the Busan monthly EHL data and the AO magnitudes were estimated to 65.5 cm (by typhoon MAEMI) and 29.5 cm (by typhoon SANBA), respectively. (2) The one level shift in 1983 is detected in Mokpo monthly MSL data, and the LS magnitude was estimated to 21.2 cm by the Youngsan River tidal estuary barrier construction. On the other hand, the RMS errors are computed about 1.95 cm (MSL), 5.11 cm (EHL), and 6.50 cm (ELL) in Busan station, and about 2.10 cm (MSL), 11.80 cm (EHL), and 9.14 cm (ELL) in Mokpo station, respectively.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.2 s.35
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• pp.167-174
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• 2005

Smaller size and higher integration of electronic components make smaller gap between metal conducting layers in electronic package. Under harsh environmental conditions (high temperature/humidity), electronic component respond to applied voltages by electrochemically ionization of metal and metal filament formation, which lead to short failure and this phenomenon is termed electrochemical migration(ECM). In this work, printed circuit board(PCB) is used for determination of ECM characteristics. Copper leads of PCB are soldered by eutectic solder alloys. Insulation breakdown time is measured at $85^{\circ}C,\;85{\%}RH$. CAF is the main mechanism of ECM at PCB. Pb is more susceptible to CAF rather than Sn, which corresponds well to the corrosion resistance of solder materials in aqueous environment. Polarization tests in chloride or chloride-free solutions fur pure metal and eutectic solder alloys are performed to understand ECM characteristics. Lifetime results show well defined log-normal distribution which resulted in biased voltage factor(n=2) by voltage scaling. Details on migration mechanism and lifetime statistics will be presented and discussed.

• Journal of Science and Technology Studies
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• v.19 no.3
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• pp.201-246
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• 2019

Information technology is sometimes considered as a cause that puts education in a big crisis, or it can be seen as a savior. In 2011, the Korean government announced that it would innovate education and build a talented nation by bringing IT into schools of public education system through the SMART education policy. The policy initiative aimed to establish a standard classroom models that can be diffused all over the country's schools so that teachers and students may become familiar of using devices such as tablet PCs and laptops. This paper analyzes how the smart classrooms caused friction in the actual education practices. To this end, I analyzed the direction and ideals of the SMART education policy by reading government policy document and design guidelines officially published, and visited three elementary schools that are actually building and operating a smart classroom environment to visit the facilities and have in-depth interviews with teachers and technicians. The ideal type of classroom proposed by the smart education policy was a package equipped with various functions at once in a neatly designed space like a "model house", but it was difficult to be used as a normal classroom in everyday life of school. Instead of copying and installing the model, each school decided to get "smart" in its own way, depending on how factors such as size, local characteristics, socioeconomic conditions of students and teachers, teacher experiences, and the level of existing infrastructure were combined. In Elementary School A, the machines tamed specific space of the school to create their own space, while following the rules of the school for being mobile. Although Elementary School B could not construct fully supported environment that encompassed the entire school, the system was organized with the help of well trained teacher's experiences in other schools. In Elementary School C, the machines are concentrated on specific classrooms and they promote teacher's professionalism. The components of the smart classroom were disassembled and recombined in context to make each school's classroom "smart".

• The Korean Journal of Archival Studies
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• no.13
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• pp.41-90
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• 2006

It's needed for the archivists to design a flexible and stable ERMS(Electronic Records Management System) which can ingest and store records through a consistent way and let users search and use records easily what they want. The basis of the design for ERMS are the conceptual composition and the logical and physical structure of the records when they are stored and managed in the ERMS. This paper explains the process of defining components and designing structure of electronic records using 3-layered approaches which consist of conceptual, logical and physical layer and shows advantages of this approaches. After benchmarking the information models of OAIS which is a reference model for the long-term preservation of digital information objects, this paper applies the model of AIP to a record as a 'Record AIP' and discusses the composition and structure of it. It's a critical task to identify mandatory or optional metadata groups which consists of the 'Record AIP's in the conceptual layer. This paper emphases that the metadata group related to services for the record information to users is required as a result of benchmarking OAIS information models. Various issues about the structure of 'Record AIP's are discussed according to the kind of preservation strategy such as migration or emulation and whether the encapsulation of records is required or not in the logical layer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.695-700
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• 2018

This paper presents the development of compact and lightweight broadband power amplifier module using HMIC (Hybrid Microwave Integrated Circuit) technology that could be high-density integration for many non-packaged microwave components into the small area of a high dielectric constant printed circuit board, such as a ceramic substrate, also using the special design and fabrication schemes for the structure of minimized electromagnetic interference to obtain the homogeneous electrical performance at the wideband frequency. The results confirmed that the small signal gain has a gain flatness of ${\pm}1.5dB$ within the range of 32 to 36 dB. In addition, the output power satisfied more than 30 dBm. The noise figure was measured within 7 dB, and OIP3 (Output Third Order Intercept Point) was more than 39 dBm. The fabricated broadband power amplifier satisfied the target specification required to electrically drive the high power amplifiers of jamming generators for electronic warfare, so the actual applicability to the system was verified. Future studies will be aimed at designing other similar microwave power amplifiers in the future.

• The Journal of the Korea Contents Association
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• v.19 no.5
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• pp.82-93
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• 2019

Fashion cannot encourage co-consumption with other people as a personal item, but it can lead to new consumer needs if fashion sharing service can professionally replace the time and cost of purchasing and managing goods. The purpose of this study is to empirically investigate the factors influencing the acceptance of fashion-sharing services based on the integration theory of user acceptance and utilization (UTAUT), and to discuss the virtuous cycle and sustainability pursuit of resources through the activation of the sharing. In this study, the research model for the acceptance of fashion sharing applications is schematized, and the survey was conducted 300 women aged 20~49 years. The screens of 'Project Anne', a representative fashion sharing service in Korea, were provided as a visual data. Reliability analysis, correlation analysis, confirmatory factor analysis, structural equation analysis, and multiple group analysis were performed using SPSS 23.0 and AMOS 22.0 statistical package for statistical analysis. As a result, efficiency and social influence positively influenced behavioral intention to use, and age has found that efficiency and social influences modulate the intensity of behavioral intention to use. Therefore, for the consumer acceptance and activation of fashion sharing services, marketing activities emphasizing efficiency and strengthening social influence factors are essential. Also, it is necessary to maintain the existing target group, 30~40s, and also construct additional products and price services for the 20s. This study is of academic significance in presenting basic data for empirical research on consumer acceptance of fashion sharing, and suggests a study on the influence relationship among user experience components for real users in the future.

• Journal of the Korean Applied Science and Technology
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• v.39 no.5
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• pp.692-700
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• 2022

In this study, the effect of e-service quality of O2O cosmetic delivery service app on satisfaction and loyalty was investigated. To this end, a total of 210 questionnaires were collected and frequency analysis, exploratory factor analysis, reliability analysis, correlation analysis, and regression analysis were performed using the statistical package SPSS 25.0. The main results are as follows. Efficiency, order fulfillment, system availability, and privacy, which are components of O2O cosmetic delivery service app e-service quality, all had a significant effect on satisfaction and loyalty. Also, satisfaction was found to have a significant effect on loyalty. In order to increase the number of consumers who use the O2O cosmetic delivery service app, it is necessary to increase the availability and efficiency of the system, which has the greatest impact on satisfaction and loyalty. To this end, it is necessary to provide a comfortable environment without interruption and fast access while using the O2O cosmetic delivery service app, and to build a system so that it can be used efficiently.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.2
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• pp.33-42
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• 2023

Throughout all industries, eco-friendliness is being promoted worldwide with focus on suppressing the environmental impact. With recent international environment policies and regulations supported by government, the electric vehicles demand is expected to increase rapidly. Battery system itself perform an essential role in EVs technology that is arranged in cells, modules, and packs, and each of them are connected mechanically and electrically. A multifaceted approach is necessary for battery pack bonding technologies. In this paper, pros and cons of applicable bonding technologies, such as resistance welding, laser and ultrasonic bonding used in constructing electric vehicle battery packs were compared. Each bonding technique has different advantages and limitations. Therefore, several criteria must be considered when determining which bonding technology is suitable for a battery cell. In particular, the shape and production scale of battery cells are seen as important factors in selecting a bonding method. While dealing with the types and components of battery cells, package bonding technologies and general issues, we will review suitable bonding technologies and suggest future directions.