• Clean Technology
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• v.21 no.1
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• pp.33-38
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• 2015

In this research, life cycle inventory database (LCI DB) was developed for liquid CO₂ employing life cycle assessment (LCA) methodology. As are result of characterization and normalization process, production of liquid CO₂ puts on environmental impact in the order of resource depletion, global warming, acidification, eutrophication and photochemical oxidation, and among a wide variety of input, electricity contributes in most of the impact categories. Air emission plays a key role in the acidification and eutrophication while ammonia affects most on the ozone depletion. It is anticipated that development of liquid CO₂ LCI DB makes it possible for national environmental strategies to be more activated including environmental labeling scheme.

• The KIPS Transactions:PartD
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• v.14D no.7
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• pp.763-772
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• 2007

Due to increased software development cost, interest about the method and automated tool for reusing legacy system have been running high. Therefore, In this study, it proves the definition, concept and also background of legacy system by showing real market and technology trend. Automation tool is designed and developed to handle the concrete development methodology, procedure and reference. Also, we implemented the process that analyze the legacy system and extract, refine, store and reuse the candidate components by using LM(Legacy to Modern System) supporting tool presented in this paper. If LM supporting tool is applied to legacy system migration, we can expect cutting costs, shortening the developing period and succeeding the intellectual property by software re-engineering.

• Journal of Microbiology and Biotechnology
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• v.29 no.2
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• pp.222-229
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• 2019

Korean ginseng (Panax ginseng Meyer) was processed by drying, steaming, or puffing, and the effects of these processes on the ginsenoside profile were investigated. The main root of 4-year-old raw Korean ginseng was dried to produce white ginseng. Steaming, followed by drying, was employed to produce red or black ginseng. In addition, these three varieties of processed ginseng were puffed using a rotational puffing gun. Puffed ginseng showed significantly higher extraction yields of ginsenosides (49.87-58.60 g solid extract/100 g of sample) and crude saponin content (59.40-63.87 mg saponin/g of dried ginseng) than non-puffed ginseng, respectively. Moreover, puffing effectively transformed the major ginsenosides (Rb1, Rb2, Rc, Rd, Re, and Rg1) of ginseng into minor ones (F2, Rg3, Rk1, and Rg5), comparable to the steaming process effect on the levels of the transformed ginsenosides. However, steaming takes much longer (4 to 36 days) than puffing (less than 30 min) for ginsenoside transformation. Consequently, puffing may be an effective and economical technique for enhancing the extraction yield and levels of minor ginsenosides responsible for the major biological activities of ginseng.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.962-977
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• 2019

The human voice is a convenient method of information transfer between different objects such as between men, men and machine, between machines. The development of information and communication technology, the voice has been able to transfer farther than before. The way to communicate, it is to convert the voice to another form, transmit it, and then reconvert it back to sound. In such a communication process, a vocoder is a method of converting and re-converting a voice and sound. The CELP (Code-Excited Linear Prediction) type vocoder, one of the voice codecs, is adapted as a standard codec since it provides high quality sound even though its transmission speed is relatively low. The EVRC (Enhanced Variable Rate CODEC) and QCELP (Qualcomm Code-Excited Linear Prediction), variable bit rate vocoders, are used for mobile phones in 3G environment. For the real-time implementation of a vocoder, the reduction of sound quality is a typical problem. To improve the sound quality, that is important to know the size and shape of noise. In the existing sound quality improvement method, the voice activated is detected or used, or statistical methods are used by the large mount of data. However, there is a disadvantage in that no noise can be detected, when there is a continuous signal or when a change in noise is large.This paper focused on finding a better way to decrease the reduction of sound quality in lower bit transmission environments. Based on simulation results, this study proposed a preprocessor application that estimates the SNR (Signal to Noise Ratio) using the spectral SNR estimation method. The SNR estimation method adopted the IMBE (Improved Multi-Band Excitation) instead of using the SNR, which is a continuous speech signal. Finally, this application improves the quality of the vocoder by enhancing sound quality adaptively.

• Resources Recycling
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• v.28 no.4
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• pp.3-14
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• 2019

Lead is one of the common non-ferrous metals used in modern industry. The usage of lead continues to increase and has risen from 5 million tonnes per year worldwide in the 1970s to 11 million tonnes in the 2010s. In principle lead is virtually 100 % recyclable as an element without loss of quality. The recycling of lead scrap reduces the energy consumption and environmental burden, comparing to the primary metal production. Therefore production of secondary lead from scrap has been steadily growing and at present it meets approximately 60 % of usage worldwide. Lead scrap (mainly lead-acid battery) is smelted in primary and secondary smelter. Most secondary lead smelting were performed in a shaft-type furnace (blast furnace), rotary furnace and reverberatory furnace. The lead bullion is either cast into ingots and re-melted in refining kettles or refining is performed on the hot lead bullion immediately after production. This work provides an overview of the primary lead production and recycling process.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.501-506
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• 2021

Under the pressure of business competition and effectiveness, more and more organizations in the world are likely to apply modern software such as enterprise resource planning (ERP) which can help them to create better organizing practice, better managing capabilities of administrators, and better operations of personnel. In Vietnam, many firms are afraid to install it and the number of firms adopting this software is limited mainly due to the insufficient scientific evidence of the successful implementation of ERP. This study aims to identify and measure the factors influencing the successful implementation of ERP of firms in Vietnam. Qualitative research methodology combined with quantitative research methodology is used. The data are surveyed with 343 administrators of 45 organizations that have successfully deployed ERP in Ha Noi and Ho Chi Minh cities. Of these 19 were excluded from analyses due to unsatisfactory responses, and only 324 were used for statistical processing. The collected data were processed by using the SPSS software. The result of the study shows that there are six factors affecting the successful implementation of ERP of firms in Vietnam, (ranked in descending order of importance), they are top management commitment and support, business process re-engineering, user involvement, project management board, vendor support, and suitability of software and hardware.

• Korean Journal of Materials Research
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• v.32 no.1
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• pp.44-50
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• 2022

Transition metal carbides (TMCs) are used to process difficult-to-cut materials due to the trend of requiring superior wear and corrosion properties compared to those of cemented carbides used in the cutting industry. In this study, TMC (TiC, TaC, Mo₂C, and NbC)-based cermets were consolidated by spark plasma sintering at 1,300 ℃ (60 ℃min) with a pressure of 60 MPa with Co addition. The sintering behavior of TMCs depended exponentially on the function of the sintering exponent. The Mo₂C-6Co cermet was fully densified, with a relative density of 100.0 %. The Co-binder penetrated the hard phase (carbides) by dissolving and re-precipitating, which completely densified the material. The mechanical properties of the TMCs were determined according to their grain size and elastic modulus: TiC-6Co showed the highest hardness of 1,872.9 MPa, while NbC-6Co showed the highest fracture toughness of 10.6 MPa^*m^1/2. The strengthened grain boundaries due to high interfacial energy could cause a high elastic modules; therefore, TiC-6Co showed a value of 452 ± 12 GPa.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.1
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• pp.1-9
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• 2022

Objectives: The purpose of this study is to evaluate exposure characteristics of lead using data from the domestic occupational exposure literature. Methods: Occupational airborne exposure data on lead reported in the domestic literature from 1981 to 2018 were collected and re-analyzed. The exposure levels in the data were expressed as an estimated arithmetic mean and a weighted arithmetic mean (WAM) of the number of samples. Lead exposure characteristics were analyzed by industry, process, and year. Results: From a total of 14 documents, 8,305 airborne lead measurements for 17 industries were identified, and the WAM concentration in eight industries exceeded the occupational exposure limit of 50 ㎍/m³. Three industries (battery manufacturing, lead smelting, and litharge manufacturing) accounted for 95% of the total data, and exposure trends could be confirmed over 10 years. Exposure levels continue to decrease in all three industries. Conclusions: Considering the distribution outlook of lead and lead compounds, the main management targets are lead storage battery manufacturing and secondary smelting for lead regeneration.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.85-96
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• 2022

The purpose of this study was to analyze the effect of service factors of used book transactions, which are becoming a major service in online bookstores, on customer satisfaction and the effect of customer satisfaction on reuse intention. 235 samples were collected through a survey for users of used book transaction services in their 20s or older, and 205 surveys were adopted through the refining process. Hypotheses were verified through factor analysis, reliability analysis, and structural model analysis using SPSS22.0 and AMOS22.0 statistical programs. Some factors were supported between service factors and customer satisfaction, and customer satisfaction had a significant effect on reuse intention, and moderating effects according to the preferred genre of reading were founded. More differentiated services should be considered according to the customer's preferred genre, as the services of online bookstores are becoming more standardized, customers do not feel differentiated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.252-254
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• 2022

The purpose of this study is to show the works of Jeju artists and ways to contribute to the Jeju tourism industry, with the research background in that it has recently continued to accept the works of Jeju contemporary artists and draws active works. As a measure to achieve this research purpose, the Deep Dream Generator software was judged to be an effective method for promoting this study. As a specific research process, we will use the Deep Dream Generator to synthesize each of the works of Jeju artists and works of famous foreign artists provided by Deep Dream Generators with their own photos of Jeju Oreum and display the results, and attempt to reinterpret Jeju Oreum using artificial intelligence. In addition, it is expected to revitalize Jeju's art works and tourism by seeking ways to use the results in Jeju tourism products.